JP2007246009A - Controller for hybrid electric car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the controller of a hybrid electric car for suppressing deterioration of a battery, by suppressing the fluctuation of the SOC of a battery, while maintaining satisfactory driving performance or exhaust gas performance of a vehicle. <P>SOLUTION: When request torque is distributed to an engine 2 and a motor 6, according to an output region determined based on the revolution speed and request torque of a motor 6, when the charging rate of a battery 18 is within a predetermined charging rate range, the output torque of the engine 2 is limited to predetermined allowable torque which is smaller than the maximum output torque of the engine 2; and when the output torque of the engine 2 is insufficient for request torque, the insufficient torque is defined as the output torque of the motor 6; and when the charging rate is lower than the predetermined charging rate range, a region where torque is distributed to the motor 6 is made smaller than that in the first case; and when the charging rate is higher than the predetermined charging rate range, a region where torque is distributed to the motor 6 is made larger than that in the first case. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for a hybrid electric vehicle, and more particularly to a control device for a hybrid electric vehicle capable of transmitting an engine driving force and an electric motor driving force to driving wheels of a vehicle.

Conventionally, a so-called parallel type hybrid electric vehicle has been developed and put into practical use in which an engine and an electric motor are mounted on a vehicle and the driving force of the engine and the driving force of the electric motor can be transmitted to the driving wheels of the vehicle, respectively.
As such a parallel type hybrid electric vehicle, a clutch for mechanically connecting and disconnecting an engine and an automatic transmission is provided, and a rotating shaft of an electric motor is connected between an output shaft of the clutch and an input shaft of the automatic transmission. For example, Patent Document 1 proposes.

In a hybrid electric vehicle as disclosed in Patent Document 1, the clutch is disengaged when starting the vehicle, the motor is operated by supplying power from the battery, and the vehicle is started only by the driving force of the motor. During traveling, the clutch is connected so that the driving force of the engine and the driving force of the electric motor can be transmitted to the driving wheels via the transmission.
When the vehicle is traveling with the clutch connected in this manner, the torque necessary for traveling the vehicle is appropriately distributed to the engine and the electric motor, the motor is operated to assist the driving force, and the vehicle is decelerated. Sometimes, the electric motor is operated to generate a regenerative braking force, and the battery is charged by converting the braking energy into electric power.

Also, in such a hybrid electric vehicle, when the battery charging rate (hereinafter referred to as SOC) decreases too much, the battery is forcibly charged by operating the motor to prevent the battery from being over-discharged. The SOC is recovered. Conversely, if the SOC increases too much, the motor is operated to prevent overcharging of the battery and the torque distribution on the motor side is increased to forcibly discharge the battery to bring the SOC to an appropriate value. I try to lower it.
JP-A-5-176405

However, there is a problem in that deterioration of the battery is promoted if the variation of the SOC is allowed to the extent that forced charging and forced discharging are performed in this way.
In general, when an engine is operated in a state where a high torque is output in a middle rotation region (for example, 700 to 2000 rpm), the NOx emission amount tends to increase.
However, when the torque distribution between the engine and the electric motor is simply controlled according to the driving state of the vehicle as in the hybrid electric vehicle of Patent Document 1, the range of fluctuation of the SOC of the battery is not considered at all. It has been difficult to suppress the deterioration of the battery due to the expansion of the SOC fluctuation range. Also, simply distributing the torque between the engine and the electric motor according to the driving state of the vehicle may result in a driving state in which the engine output torque is high in the middle rotation range, and such a driving state continues. In this case, there is a problem that the amount of NOx emission from the engine increases.

  The present invention has been made in view of such problems, and the object of the present invention is to suppress battery deterioration by suppressing fluctuations in the SOC of the battery while maintaining good driving performance and exhaust gas performance of the vehicle. An object of the present invention is to provide a control apparatus for a hybrid electric vehicle that can be used.

  In order to achieve the above object, the hybrid electric vehicle control device of the present invention is capable of transmitting the driving force of the engine and the driving force of the electric motor to the driving wheels of the vehicle, respectively, according to the driving state of the vehicle. In a control apparatus for a hybrid electric vehicle configured to control the engine and the electric motor based on the required drive torque obtained, when the electric motor operates as a motor, electric power is supplied to the electric motor, and the electric motor serves as a generator. A battery in which the electric power generated by the motor is charged when operating, a charge rate detection means for detecting a charge rate of the battery, a rotation speed detection means for detecting the rotation speed of the motor, and the rotation speed detection means. The required torque is increased with the engine according to an output range determined based on the detected rotation speed of the motor and the required torque. And a control means for controlling the engine and the electric motor in accordance with each of the distributed torques, the control means having the charge rate detected by the charge rate detection means as a predetermined charge. In the first case within the rate range, the engine output torque is limited to a predetermined allowable torque smaller than the maximum engine output torque at the engine speed at that time, and the engine output torque is the required torque. In the second case, the output region is set so that the shortage is the output torque of the electric motor, and the charge rate detected by the charge rate detection means is lower than the predetermined charge rate range. In the output region, the region in which torque is distributed to the motor is reduced more than in the first case, while the charging rate detection means is used. In the third case where the detected charging rate is higher than the predetermined charging rate range, a region in which torque is distributed to the electric motor in the output region is expanded as compared to the first case ( Claim 1).

According to the hybrid electric vehicle control apparatus configured as described above, the control means outputs based on the rotational speed of the electric motor detected by the rotational speed detection means and the required drive torque obtained in accordance with the driving state of the vehicle. According to the region, the required torque is distributed to the engine and the electric motor, and the engine and the electric motor are controlled according to the allocated torque.
At this time, in the first case where the charging rate of the battery detected by the charging rate detection means is within the predetermined charging rate range, the engine output torque is smaller than the maximum engine output torque at the engine speed at that time. The engine torque is limited to a predetermined allowable torque, and when the output torque of the engine is insufficient with respect to the required torque, the shortage is set as the output torque of the electric motor.

Further, in the second case where the charging rate of the battery detected by the charging rate detecting means is lower than the predetermined charging rate range, the region where the torque is distributed to the motor in the output region is reduced as compared with the first case. Thereby, the energy consumption from the battery by an electric motor reduces from the 1st case.
On the other hand, in the third case where the charging rate of the battery detected by the charging rate detecting means is higher than the predetermined charging rate range, the region where the torque is distributed to the motor in the output region is expanded as compared with the first case. As a result, the amount of energy consumed from the battery by the electric motor increases compared to the first case.

  Further, in the hybrid electric vehicle control apparatus, a filter for collecting particulates contained in the exhaust of the engine, and a regeneration means for regenerating the filter by incinerating the particulates collected and accumulated in the filter The control means, in the first case, when the regeneration of the filter is performed by the regeneration means, compared with a case where the regeneration of the filter is not performed, in the low rotation region of the engine. The output region is determined so that the allowable torque increases and the allowable torque decreases in a high rotation region of the engine (claim 2).

According to the hybrid electric vehicle control apparatus configured as described above, when the control means distributes the required torque in the first case, when the regeneration of the filter is performed by the regeneration means, the regeneration of the filter is not performed. The allowable torque is increased in the low engine speed range and the allowable torque is decreased in the high engine speed range as compared with the case where the engine is not performed.
As a result, the output torque of the engine in the first case can be increased in the low engine rotation region when the filter is regenerated and when the filter is not regenerated. In the high rotation region, the limit is smaller.

  Further, in such a control apparatus for a hybrid electric vehicle, in the third case, when the filter is not regenerated, the control means determines the output torque of the motor first and uses the rest as the output of the engine. On the other hand, when the regeneration of the filter is performed, the output region is determined so that the output torque of the engine is determined first and the rest is set as the output torque of the electric motor (claim 3).

  According to the control apparatus for a hybrid electric vehicle configured as described above, the control means determines the output torque of the electric motor first when the required torque is distributed in the third case and the filter is not regenerated. When the output torque of the motor is insufficient with respect to the required torque, the rest is set as the engine output torque. On the other hand, when the filter is regenerated, the output torque of the engine is determined first, and when the output of the engine is insufficient with respect to the required torque, the remaining is set as the output torque of the motor.

More specifically, in such a control apparatus for a hybrid electric vehicle, the output area when the filter is regenerated in the third case is regenerated, and the filter is regenerated in the first case. It is the same as the output area at the time (claim 4).
According to the hybrid electric vehicle control apparatus configured as described above, the same is true when the filter is regenerated in the third case and when the filter is regenerated in the first case. Torque is distributed to the engine and the electric motor based on the output region.

  In the control apparatus for a hybrid electric vehicle, in the second case, the control means allows the output torque of the engine up to the maximum output torque of the engine at the engine speed at that time. When the output torque is insufficient with respect to the required torque, the output region is defined so that the shortage is the output torque of the electric motor.

  According to the hybrid electric vehicle control apparatus configured as described above, when the control means distributes the required torque in the second case, the engine output torque is set to the maximum output of the engine at the engine speed at that time. Torque is allowed, and when the engine output torque is insufficient with respect to the required torque, the shortage is set as the output torque of the electric motor. By doing in this way, the area | region where torque is allocated to an engine among output area | regions expands rather than the said 1st case, As a result, the area | region where torque is allocated to an electric motor becomes smaller than the 1st case.

  The control device for the hybrid electric vehicle further includes a clutch capable of disconnecting the transmission of the driving force from the engine to the driving wheel while maintaining the transmission of the driving force from the electric motor to the driving wheel. In the third case, the control means permits the output torque of the electric motor to the maximum torque that can be output by the electric motor at the rotation speed of the electric motor at that time, and when the required torque is less than the maximum torque, the control means And when the maximum torque is insufficient with respect to the required torque, the clutch is connected to make the output torque of the electric motor the required torque and the lack thereof. The output region is determined so that the minute is the output torque of the engine (claim 6).

  According to the hybrid electric vehicle control device configured as described above, when the control means distributes the required torque in the third case, the maximum output torque of the motor can be output at the rotation speed of the motor at that time. Torque is allowed, and when the required torque is below the maximum torque, the motor is controlled so that the clutch is disconnected and the required torque is output only by the electric motor. As a result, the clutch is disengaged while the required torque is equal to or less than the maximum torque, and the required torque is output only by the electric motor.

  On the other hand, when allocating the required torque in the third case, the control means connects the clutch when the output torque of the motor is the maximum torque but is insufficient with respect to the required torque, and uses the shortage as the engine output torque. To control. As a result, the sum of the output torque of the electric motor set to the maximum torque and the output torque of the engine transmitted via the clutch becomes the required torque.

  In the control apparatus for a hybrid electric vehicle, the control means determines the output torque of the electric motor first when the vehicle starts in any of the first to third cases. The remaining output is the output torque of the engine, and the output region is determined so as to allow the output of the electric motor up to the maximum torque that can be output from the electric motor at the rotation speed of the electric motor at that time. Item 7).

According to the hybrid electric vehicle control apparatus configured as described above, when the required torque is distributed at the start of the vehicle in any of the first to third cases, the output torque of the motor Is determined first, and the remainder is set as the output torque of the engine, and the output of the motor is allowed up to the maximum torque that can be output from the motor at the rotation speed of the motor at that time.
More specifically, in such a hybrid electric vehicle control device, the transmission of the driving force from the engine to the driving wheel can be cut off while the transmission of the driving force from the electric motor to the driving wheel is maintained. The control means further includes a clutch that disengages the clutch when the required torque is equal to or less than a maximum torque that can be output from the motor at a rotational speed of the motor at the time of starting the vehicle. Controls the electric motor to output the required torque, while when the required torque is greater than the maximum torque, the sum of the output torque of the motor and the torque output from the clutch becomes the required torque. It controls the engagement state of the clutch and the output torque of the engine and the electric motor. Section 8).

According to the hybrid electric vehicle control apparatus configured as described above, when the vehicle starts, the clutch is disengaged if the required torque is equal to or less than the maximum torque that can be output from the motor at the number of rotations of the motor at that time. The motor is controlled to output the required torque.
On the other hand, when the required torque is greater than the maximum torque at the start of the vehicle, the engine and motor are controlled while controlling the clutch connection state so that the sum of the output torque of the motor and the torque output from the clutch becomes the required torque. The output torque is controlled.

  According to the control apparatus for a hybrid electric vehicle of the present invention, in the first case where the charging rate of the battery is within the predetermined charging rate range, the maximum output torque of the engine at the engine speed at that time is determined as the engine output torque. By limiting to a smaller predetermined allowable torque, the engine can be operated while avoiding a high torque region where the NOx emission amount increases in the middle rotation region, and an increase in the NOx emission amount can be prevented.

Further, at this time, when the engine output torque is insufficient with respect to the required torque, the shortage is used as the output torque of the electric motor, thereby suppressing the decrease in the driving performance of the vehicle due to the limitation of the engine output torque. .
In the second case where the charging rate of the battery is lower than the predetermined charging rate range, the region where the torque is distributed to the motor is reduced compared to the first case in the output region determined by the rotation speed of the motor and the required torque. By doing so, the amount of energy consumed from the battery by the electric motor is reduced compared to the first case. As a result, the amount of energy consumed from the battery by the electric motor is reduced, and further reduction in the charging rate can be suppressed.

If the vehicle travels at a reduced speed during this time and regenerative braking is performed by the electric motor, it is possible to recover the charge rate of the battery by recovering energy during deceleration and to return it to the predetermined charge rate range.
Further, in the third case where the charging rate of the battery is higher than the predetermined charging rate range, the region where the torque is distributed to the motor in the output region is expanded from that in the first case, so that The amount of energy consumption increases from the first case. As a result, the amount of energy consumed from the battery by the electric motor increases, and further increase in the charging rate can be suppressed, and the charging rate can be returned to the predetermined charging rate range.

Thus, when the charging rate of the battery is not within the predetermined charging rate range, the output range of the motor torque determined by the number of rotations of the motor and the required torque is changed, and further fluctuations in the direction of deterioration of the charging rate. Therefore, it is possible to suppress the deterioration of the battery due to the large change in the charging rate.
According to the control apparatus for a hybrid electric vehicle of claim 2, when the required torque is distributed in the first case, when the regeneration of the filter is performed by the regeneration means, the regeneration of the filter is not performed. In comparison with the above, the allowable torque is increased in the low engine speed range and the allowable torque is decreased in the high engine speed range. As a result, when the filter is regenerated, it is possible to increase the output torque of the engine in the low engine speed range and in the high engine speed range than when the filter is not regenerated. The engine output is limited to a smaller value.

For this reason, when the filter is regenerated in the first case, the engine output torque increases in the low engine speed region where the exhaust temperature does not easily rise, so that the exhaust temperature required for filter regeneration can be easily obtained. Thus, it is possible to prevent the deterioration of fuel consumption and the failure of filter regeneration due to prolonged filter regeneration.
In the first case, the battery charge rate is within the predetermined charge rate range. Thus, the amount of battery power consumed by the motor due to the increase in the engine output torque in the low engine speed range. Decrease. On the other hand, in the high engine speed region, the ratio of the engine output torque to the required torque decreases and the ratio of the motor output torque increases, so that the battery power is consumed correspondingly.

For this reason, even if the electric power consumption by the electric motor decreases in the low engine speed range, the battery charging rate does not increase excessively due to the increased electric power consumption by the electric motor in the high engine speed range. While maintaining in the charge rate range, it is possible to suppress deterioration of the battery and to prevent an increase in NOx emission from the engine.
According to the control device for a hybrid electric vehicle of claim 3, when distributing the required torque in the third case, when the filter is not regenerated, the output torque of the motor is determined first, and the rest is determined by the engine. Output torque. As a result, the output torque of the electric motor can be set with priority, and the output torque of the electric motor can be controlled to prevent an increase in the charging rate of the battery or to quickly return to the predetermined charging rate range. Can be easily obtained without being influenced by the output torque of the engine.

On the other hand, when the filter is regenerated, the engine output torque is determined and the remainder is used as the output torque of the motor, so that the engine output can be preferentially set, and the exhaust temperature required for filter regeneration can be set. The engine output torque that can be obtained can be easily obtained without being influenced by the output torque of the electric motor.
According to the control device for a hybrid electric vehicle of claim 4, the distribution of the required torque in the third case when the filter is regenerated is divided into the distribution of the required torque in the first case when the filter is regenerated. Same as the required torque distribution. By doing in this way, the map and arithmetic expression for distributing the required torque when the filter is regenerated can be shared between the first case and the third case, and the control is efficiently performed. And the capacity of a storage device for storing maps and arithmetic expressions can be reduced.

  According to the hybrid electric vehicle control apparatus of the fifth aspect, in the second case, the engine output torque is allowed up to the maximum engine output torque at the engine speed at that time. The engine torque output range determined by the number of rotations and the required torque is maximized. As a result, the possibility of torque being distributed to the motor is reduced, and the output torque of the motor when used in combination with the engine torque can be kept as small as possible, and the energy consumption from the battery by the motor is minimized. In addition, it is possible to effectively suppress a decrease in the charging rate of the battery.

Furthermore, when the output torque of the engine is insufficient with respect to the required torque at this time, the required torque required for traveling of the vehicle can be reliably obtained by setting the shortage as the output torque of the electric motor. It is possible to prevent a decrease in driving performance of the vehicle due to insufficient torque.
According to the hybrid electric vehicle control apparatus of the sixth aspect, in the third case, when the required torque is less than the maximum torque that can be output at the number of rotations of the motor at that time, the clutch is disconnected and the request is made only by the motor. Output torque. As a result, the output range of the motor torque determined by the number of revolutions of the motor and the required torque is maximized, the energy consumption from the battery by the motor is maximized, and the increase in the charging rate of the battery is effectively suppressed. The charging rate can be returned to the predetermined charging rate range.

In addition, even if the output torque of the motor is the maximum torque at this time, the clutch is connected and the insufficient torque is output from the engine when the required torque is insufficient. Therefore, the required torque necessary for running the vehicle is ensured. Therefore, it is possible to prevent a decrease in driving performance of the vehicle due to insufficient torque.
According to the control apparatus for a hybrid electric vehicle of claim 7, in any case of the first to third cases, when the vehicle starts, the output torque of the electric motor is determined first. The remaining is the engine output torque, and the output of the motor is allowed up to the maximum torque that can be output from the motor at the number of rotations of the motor at that time. In this way, by avoiding the use of an engine with relatively low driving efficiency as much as possible in the low rotation speed region, the fuel efficiency is improved and the vehicle torque is positively used when starting the vehicle. You can start smoothly.

Furthermore, if the required torque is larger than the maximum torque of the motor at this time, the shortage is compensated by the output torque of the engine, and the required torque necessary for starting the vehicle is obtained reliably, so that the driving feeling is reduced due to insufficient torque. Can be prevented.
According to the control apparatus for a hybrid electric vehicle of the eighth aspect, when the motor can output the required torque when the vehicle starts, the clutch is disengaged and the driving wheels are driven only by the driving force of the motor. Therefore, by not using an engine with relatively low driving efficiency in the low speed range for driving the drive wheels, the fuel consumption is further improved, and the vehicle is further improved by using only the motor torque when starting the vehicle. You can start smoothly.

  Further, when the required torque is larger than the maximum torque when the vehicle starts, the engine and motor are controlled while controlling the clutch connection state so that the sum of the output torque of the motor and the torque output from the clutch becomes the required torque. Since the output torque is controlled, it is possible to reliably obtain the required torque required for starting the vehicle and to prevent the driving feeling from being lowered due to insufficient torque.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a main part of a control device for a hybrid electric vehicle 1 according to an embodiment of the present invention. An input shaft of a clutch 4 is connected to an output shaft of a diesel engine (hereinafter referred to as an engine) 2, and the output shaft of the clutch 4 is an automatic transmission via a rotating shaft of a permanent magnet type synchronous motor (hereinafter referred to as an electric motor) 6. 8 input shafts (hereinafter referred to as transmissions) are connected. The output shaft of the transmission 8 is connected to the left and right drive wheels 16 via a propeller shaft 10, a differential device 12 and a drive shaft 14.

Therefore, when the clutch 4 is connected, both the output shaft of the engine 2 and the rotating shaft of the electric motor 6 can be mechanically connected to the drive wheels 16 via the transmission 8, and the clutch 4 is disconnected. Sometimes only the rotating shaft of the electric motor 6 can be mechanically connected to the drive wheels 16 via the transmission 8.
The electric motor 6 operates as a motor when DC power stored in the battery 18 is converted into AC power by the inverter 20 and supplied thereto, and the output torque of the motor 6 is changed to an appropriate speed by the transmission 8. 16 is transmitted. Further, when the vehicle is decelerated, the electric motor 6 operates as a generator, and kinetic energy generated by the rotation of the drive wheels 16 is transmitted to the electric motor 6 through the transmission 8 and converted into AC power, thereby generating a regenerative braking force. Then, the AC power is converted into DC power by the inverter 20, and then charged in the battery 18. The kinetic energy generated by the rotation of the drive wheels 16 is recovered as electric energy.

  On the other hand, the output torque of the engine 2 is transmitted to the transmission 8 via the rotating shaft of the electric motor 6 when the clutch 4 is connected, and is transmitted to the drive wheels 16 after being shifted to an appropriate speed. It has become. Therefore, when the electric motor 6 operates as a motor when the output torque of the engine 2 is transmitted to the drive wheels 16, the output torque of the engine 2 and the output torque of the electric motor 6 are driven via the transmission 8, respectively. It will be transmitted to the wheel 16. That is, a part of the torque to be transmitted to the drive wheels 16 for driving the vehicle is supplied from the engine 2 and the remaining part is supplied from the electric motor 6.

When the charging rate (hereinafter referred to as SOC) of the battery 18 decreases and the battery 18 needs to be charged, the electric motor 6 operates as a generator, and the electric motor 6 is operated using a part of the output torque of the engine 2. Power generation is performed by driving, and the generated AC power is converted into DC power by the inverter 20 and then the battery 18 is charged.
The vehicle ECU 22 (control means) controls the connection / disconnection of the clutch 4 and the transmission 8 according to the operating state of the vehicle and the engine 2 and information from the engine ECU (regeneration means) 24, the inverter ECU 26, and the battery ECU 28. In addition to performing gear change control, integrated control for appropriately operating the engine 2 and the electric motor 6 is performed in accordance with various control states such as these control states and vehicle start, acceleration, and deceleration.

  When the vehicle ECU 22 performs such control, the accelerator opening sensor 32 that detects the depression amount of the accelerator pedal 30, the vehicle speed sensor 34 that detects the traveling speed of the vehicle, and the rotation that detects the rotation speed of the electric motor 6. Based on the detection result of the number sensor (rotational speed detection means) 36, a required torque required for traveling of the vehicle is calculated, and a torque generated by the engine 2 and a torque generated by the electric motor 6 are set from the required torque. .

The rotational speed of the electric motor 6 detected by the rotational speed sensor 36 coincides with the rotational speed of the engine 2 when the clutch 4 is connected.
The engine ECU 24 performs various controls necessary for the operation of the engine 2 itself, such as start / stop control of the engine 2 and idle control, and the engine 2 generates torque required for the engine 2 set by the vehicle ECU 22. Thus, the fuel injection amount and injection timing of the engine 2 are controlled.

The inverter ECU 26 controls the operation of the electric motor 6 by operating the motor or the generator by controlling the inverter 20 based on the torque that should be generated by the electric motor 6 set by the vehicle ECU 22.
The battery ECU (charge rate detection means) 28 detects the temperature of the battery 18, the voltage of the battery 18, the current flowing between the inverter 20 and the battery 18, and obtains the SOC of the battery 18 from these detection results. The obtained SOC is sent to the vehicle ECU 22 together with the detection result.

The exhaust passage 38 of the engine 2 is provided with an exhaust aftertreatment device 40 for purifying the exhaust of the engine. An oxidation catalyst 42 is disposed in the exhaust aftertreatment device 40, and the oxidation catalyst 42 A particulate filter (hereinafter referred to as a filter) 44 is disposed on the downstream side.
The filter 44 is made of a honeycomb-type ceramic carrier, and a large number of passages communicating the upstream side and the downstream side are arranged side by side, and the upstream side opening and the downstream side opening of the passage are alternately closed. The exhaust of the engine 2 is purified by collecting particulates contained in the exhaust.

Further, the oxidation catalyst 42 oxidizes and purifies CO (carbon monoxide) and HC (hydrocarbon) contained in the exhaust of the engine 2, and the amount of particulates deposited on the filter 44 increases, so that the filter 44 is regenerated. It is provided to oxidize HC supplied into the exhaust passage 38 of the engine 2 and raise the temperature of the exhaust gas flowing into the filter 44 when necessary.
Control for regeneration of the filter 44 is performed by the engine ECU 24, and the contents thereof are as follows.

When the engine ECU 24 determines that the accumulated amount of particulates in the filter 44 has become equal to or greater than a predetermined amount from the difference in exhaust pressure before and after the filter 44, the engine ECU 24 starts the regeneration control of the filter 44.
In order to regenerate the filter 44, it is necessary to oxidize the HC in the exhaust gas by the oxidation catalyst 42 as described above to raise the temperature of the exhaust gas flowing into the filter 44. However, the oxidation catalyst 42 oxidizes the HC. When the exhaust temperature of the engine 2 is not sufficiently increased to a possible activation temperature (for example, 250 ° C.), additional fuel injection is performed in the expansion stroke separately from the main injection of fuel into the combustion chamber of the engine 2, The exhaust temperature is raised by burning fuel in the exhaust port 2 and exhaust manifold (both not shown) or by reducing the amount of intake air.

  When the exhaust temperature reaches a temperature at which HC can be oxidized by the oxidation catalyst 42, the engine ECU 24 performs post injection in the exhaust stroke separately from the main fuel injection, or a fuel addition valve (not shown) is provided in the exhaust passage 38. In this case, fuel is injected from the fuel addition valve into the exhaust passage 38 to supply HC into the exhaust. The HC in the exhaust is oxidized by the oxidation catalyst 42 to raise the temperature of the exhaust, and the temperature of the exhaust flowing into the filter 44 rises to a temperature at which particulates can be combusted (for example, 600 ° C.). The accumulated particulates are incinerated, and the filter 44 is regenerated.

When the pressure difference between the front and rear of the filter 44 is reduced by burning the particulates in the filter 44, the engine ECU 24 ends the regeneration control assuming that the regeneration of the filter 44 is completed.
In the hybrid electric vehicle 1 configured as described above, the following control is performed around the vehicle ECU 22 in order to drive the vehicle.

  First, when the vehicle is stopped, the engine 2 is stopped, and the change lever (not shown) of the transmission 8 is in the neutral position, the driver starts the engine 2 with a starter switch (not shown). When the operation is performed, the vehicle ECU 22 confirms that the transmission 8 is in the neutral position, the mechanical connection between the electric motor 6 and the drive wheel 16 is cut off, and the clutch 4 is connected, and then the inverter ECU 26 Is instructed with respect to the output torque of the electric motor 6 necessary for starting the engine 2 and the engine ECU 24 is instructed to operate the engine 2.

Based on an instruction from the vehicle ECU 22, the inverter ECU 26 operates the motor 6 to generate torque, cranks the engine 2, and the engine ECU 24 starts supplying fuel to the engine 2, thereby starting the engine 2. Idle operation.
After the engine 2 is started in this way, when the driver operates the change lever to the drive position or the like, the clutch 4 is disengaged and the transmission 8 is switched from the neutral state to the starting gear stage, and the accelerator pedal 30 is further depressed. When the vehicle is stepped on, the vehicle ECU 22 sets a required torque to be transmitted to the transmission 8 in order to start and run the vehicle according to the depression amount of the accelerator pedal 30 detected by the accelerator opening sensor 32.

The vehicle ECU 22 stores in advance a control map indicating an output region in which the torque distributed to the engine 2 and the electric motor 6 is determined based on the required torque and the rotational speed of the electric motor 6, and using this control map, The torque to be output by the engine 2 and the electric motor 6 is distributed and set, and the clutch 4 and the transmission 8 are controlled as necessary.
There are a plurality of control maps stored in the vehicle ECU 22, which are used by appropriately switching depending on the SOC of the battery 18 detected by the battery ECU 28 and whether or not the filter 44 is regenerated. A control map is shown.

When switching between control maps, it is not necessary to immediately switch from one control map to the other, but during a predetermined transition period, the control amount corresponding to one control map and the other Switching is performed gradually while performing interpolation processing so that the control amount is between the control amounts according to the control map.
FIG. 2 shows a control map A used when the SOC of the battery 18 is within a predetermined SOC range (for example, 40 to 50%) (first case) and the filter 44 is not regenerated. .

  As shown in FIG. 2, the control map A defines the torque output region of the engine 2 and the electric motor 6 based on the rotation speed of the electric motor 6 and the required torque, and in the region below the upper limit value Tmax of the required torque. It is divided into several output areas by a solid line in the figure. Such a configuration of the control map is the same in the control maps of FIGS. 3 to 5, and the method of dividing the output area is different in each control map.

In the control map A of FIG. 2, the output region is divided with the rotational speed N1 as a boundary, and the rotational speed N1 substantially coincides with the idle rotational speed (for example, 650 rpm) of the engine 2.
2 indicates the maximum torque Tm that can be output by the electric motor 6 at each rotational speed. This maximum torque Tm is preset according to the rotational speed of the electric motor 6 based on the specifications of the electric motor 6 as an output torque at which the electric motor 6 and the battery 18 do not overheat when the electric motor 6 is continuously operated. As shown in FIG. 6, the rotation region below the rotation speed N1 overlaps the solid line indicating the boundary of the output region.

  In such a control map A, the output region is divided into two regions, M11 and E11, with a curve indicating the maximum torque Tm of the electric motor 6 as a boundary in the rotation region where the rotational speed is N1 or less. When the point determined by the rotational speed of the electric motor 6 and the required torque is within the region M11, the rotational speed of the electric motor 6 is lower than the idle rotational speed of the engine 2, and the required torque is output only by the electric motor 6. Therefore, the clutch 4 is disengaged and only the output torque from the electric motor 6 is transmitted to the transmission 8.

  In addition, when the point determined by the rotation speed and the required torque of the electric motor 6 is within the region E11, the required torque cannot be obtained only by the maximum torque Tm of the electric motor 6, and therefore the electric motor 6 has the rotation speed at that time. The corresponding maximum torque Tm is output, and the amount of shortage of the maximum torque Tm with respect to the required torque is supplied from the engine 2 and the clutch 4 is put into a half-clutch state. I am trying not to.

  In the rotation region higher than the rotation speed N1, the output region is divided into three regions E12, M12, and E13, and the boundary line between the region E12 and the region M12 is the engine 2 as shown by the two-dot chain line in the figure. This corresponds to an allowable torque set smaller than the maximum torque Te that can be output. Such an allowable torque is generally provided to keep the output torque of the engine 2 in a region where the NOx emission amount is relatively small because the NOx emission amount of the engine 2 tends to increase in the region of the high output torque. It has been.

When the required torque is in such a region E12, control is performed so that the clutch 4 is connected and the output torque of the electric motor 6 is set to 0 N · m, and only the engine 2 outputs the required torque.
The region M12 is an output region obtained by adding the maximum torque Tm of the electric motor 6 to the region E12. When the point determined by the rotational speed of the electric motor 6 and the required torque is within the region M12, the clutch 4 is connected. Then, the output torque of the allowable torque is output from the engine 2 and the electric motor 6 outputs the amount of the output torque of the engine 2 that is insufficient with respect to the required torque.

  The region E13 is a region in which the required torque cannot be obtained only by the sum of the allowable torque output from the engine 2 and the maximum torque Tm output from the electric motor 6, and is limited when the vehicle suddenly accelerates or climbs up. The required torque may enter such a region E13 when the conditions are met. When the point determined by the rotation speed and the required torque of the electric motor 6 is within the region E13, the clutch 4 is brought into the connected state, the maximum torque Tm is output from the electric motor 6, and the output torque of the engine and the output of the electric motor are output. The engine output torque is increased from the allowable torque so that the sum of the torque becomes the required torque.

Next, FIG. 3 shows a case where the SOC of the battery 18 is within the predetermined SOC range, when the filter 44 is being regenerated, and when the SOC of the battery 18 is larger than the predetermined SOC range (third case). ) Shows a control map B used when the filter 44 is being regenerated.
The dashed-dotted line in FIG. 3 indicates the maximum torque Tm that can be output by the motor 6 at each rotational speed, as in FIG. 2, and overlaps the solid line indicating the boundary of the region in the region below the rotational speed N1. ing. Further, in the area below the rotation speed N1, the output area is divided into two areas M21 and E21. These areas M21 and E21 are exactly the same as the areas M11 and E11 in the control map A of FIG. .

  In the rotation region higher than the rotation speed N1, the output region is divided into two regions E22 and M22 as shown in FIG. 3, and the boundary between the region E22 and the region M22 corresponds to the allowable torque of the engine 2. . When the point determined by the rotation speed and the required torque of the electric motor 6 is in the area E22, the clutch 4 is connected and the electric motor 6 is connected as in the area E12 when the control map A of FIG. 2 is used. Control is performed so that the output torque is 0 N · m, and only the engine 2 outputs the required torque.

When the required torque is within the region M22, the clutch 4 is connected to output the output torque of the allowable torque from the engine 2 as in the region M12 when using the control map A of FIG. The motor 6 is made to output the amount of output torque of the engine 2 that is insufficient with respect to the required torque.
3 indicates the boundary between the region E12 and the region M12 in the control map A of FIG. 2, and the filter 44 is regenerated in a rotational region lower than the rotational speed N2 (for example, 1800 rpm). While the allowable torque is larger than the allowable torque when the filter 44 is not regenerated, the allowable torque when the filter 44 is regenerated performs the regeneration of the filter 44 in the rotation region higher than the rotation speed N2. It is smaller than the allowable torque when there is no.

That is, the clutch 4 is connected in the rotation range higher than the rotation speed N1, and the rotation speed of the electric motor 6 and the rotation speed of the engine 2 coincide with each other. Therefore, in the low rotation area of the engine 2 lower than the rotation speed N2, the filter 44 is provided. When the regeneration is performed, the allowable torque is larger than when the filter 44 is not regenerated, so that a large torque can be output from the engine 2.
Further, in the high engine speed range of the engine 2 higher than the rotational speed N2, the output torque of the engine 2 is reduced because the allowable torque is smaller when the filter 44 is regenerated than when the filter 44 is not regenerated. It can be suppressed. For this reason, as shown in FIG. 3, the output torque of the electric motor 6 is larger by that amount when the regeneration of the filter 44 is not performed than when the regeneration is performed.

  In the control map B, since the allowable torque is increased in the low rotation region of the engine 2 in this way, the sum of the allowable torque of the engine 2 and the maximum torque of the electric motor 6 is the required torque in the region higher than the rotation speed N1. Since it exceeds the upper limit value Tmax, an area such as the area E13 of the control map A is not necessary. Therefore, if the sum of the allowable torque and the maximum torque Tm of the electric motor 6 is insufficient with respect to the required torque even if the allowable torque is increased in the low rotation region of the engine 2 due to the characteristics of the engine 2 and the electric motor 6, the filter An area corresponding to the area E13 of the control map A may be provided also in the control map B in the case of performing the reproduction of 44 to ensure the driving performance of the vehicle.

  As described above, when the SOC of the battery 18 is within the predetermined SOC range, in the rotational range higher than the rotational speed N1, the engine output torque is a predetermined allowable torque smaller than the engine maximum output torque at the engine rotational speed at that time. When the engine output torque is insufficient with respect to the required torque, the shortage is used as the output torque of the electric motor. When the filter is regenerated, the permissible torque is increased in the low engine speed range and the permissible torque is decreased in the high engine speed range compared to when the filter is not regenerated.

FIG. 4 shows a control map C used when the SOC of the battery 18 is lower than the predetermined SOC range (second case) regardless of whether or not the filter 44 is being regenerated.
4 indicates the maximum torque Tm that can be output by the electric motor 6 at each rotation speed, as in the case of FIGS. 2 and 3, and indicates the boundary of the area in the rotation area below the rotation speed N1. It overlaps with the solid line. In the region lower than the rotational speed N1, the output region is divided into two regions M31 and E31. These regions M31 and E31 are exactly the same as regions M11 and E11 in the control map A of FIG. .

  In the rotation range higher than the rotation speed N1, the output area is divided into two areas E32 and M32 as shown in FIG. 3, and the engine 2 can output the boundary between the area E32 and the area M32 at the rotation speed at that time. It corresponds to the maximum torque Te. When the point determined by the rotation speed and the required torque of the electric motor 6 is in the area E32, the clutch 4 is connected and the electric motor 6 is connected as in the area E12 when the control map A of FIG. Control is performed so that the output torque is 0 N · m, and only the engine 2 outputs the required torque.

Further, when the required torque is within the region M32, the clutch 4 is connected to output the maximum torque Te from the engine 2, and the amount of the output torque of the engine 2 that is insufficient with respect to the required torque is output to the electric motor 6. Let
As described above, when the SOC of the battery 18 is lower than the predetermined SOC range, in the rotation range higher than the rotation speed N1, the output torque of the engine 2 is allowed up to the maximum torque Te, whereby the torque is applied to the engine 2 in the control map C. The area E32 to be distributed is enlarged more than the area E12 of the control map A in FIG. 2, and as a result, the area M32 to which torque is distributed to the electric motor 6 is reduced more than the area M12 of the control map A in FIG.

  When the SOC of the battery 18 is lower than the predetermined SOC range, the output torque of the engine 2 is allowed up to the maximum torque in this way, so that the SOC of the battery 18 is within the predetermined SOC range. In addition, it is assumed that there is no need to switch the control map in accordance with the necessity of regeneration of the filter 44, and the common control map C is used regardless of the necessity of regeneration of the filter 44.

FIG. 5 shows a control map D used when the SOC of the battery 18 is higher than the predetermined SOC range (third case) and the filter 44 is not regenerated.
In the control map D of FIG. 5, the rotational speed N1 is not defined as a boundary as in the other three control maps A to C described so far, and the maximum torque Tm that can be output by the electric motor 6 at each rotational speed is defined as a boundary. Are divided into two areas M41 and E41. Therefore, as long as the rotational speed region is equal to or lower than the rotational speed N1, the maximum torque Tm that can be output by the electric motor 6 is the boundary in the other three control maps A to C. This is exactly the same as the areas M11 and E11 in the map A.

Further, in the control map D of FIG. 5, even in the rotational region higher than the rotational speed N1, it is divided into two regions M41 and E41, and a point determined by the rotational speed of the motor 6 and the required torque is in the region M41. The clutch 4 is disengaged and only the output torque from the electric motor 6 is transmitted to the transmission 8.
On the other hand, when the point determined by the rotational speed and the required torque of the electric motor 6 is in the region E41, the required torque cannot be obtained only by the maximum torque Tm of the electric motor 6, and therefore the electric motor 6 has the rotational speed at that time. The corresponding maximum torque Tm is output, and the clutch 4 is connected to output from the engine 2 the amount that the maximum torque Tm is insufficient with respect to the required torque.

  As described above, when the SOC of the battery 18 is higher than the predetermined SOC range, the output torque of the electric motor 6 is allowed up to the maximum torque Tm in the rotational speed region higher than the rotational speed N1, and the clutch is disengaged only by the electric motor 6. By outputting the required torque, the region M41 in which the torque is distributed to the electric motor 6 in the relatively high rotational speed region as shown in FIG. 5 is larger than the region M12 in the control map of FIG.

  Further, when the regeneration of the filter 44 is performed when the SOC of the battery 18 is higher than the predetermined SOC range, the control map B of FIG. 3 is used as described above. When the filter 44 is not regenerated, the output torque of the electric motor 6 is preferentially set by using the control map D of FIG. 5, but when the filter 44 is regenerated, the control map of FIG. By using B, the output torque of the engine 2 that preferentially sets the output torque of the engine 2 and can obtain the exhaust temperature necessary for the regeneration of the filter 44 depends on the output torque of the electric motor 6. It can be easily obtained without any problems.

  Further, the control map B of FIG. 3 is used for the regeneration of the filter 44 by expanding the region where the torque is distributed to the engine 2 in the low rotation region of the engine 2 as compared with the control map A of FIG. While making it easy to obtain the required exhaust temperature, the increase in the SOC accompanying the decrease in the output torque of the electric motor 6 in the low rotation region of the engine 2 is expanded, and the region where the torque is distributed to the electric motor 6 in the high rotation region of the engine 2 is expanded. Therefore, the control map is suitable when the filter 44 is regenerated.

As described above, the regions where the torque is distributed to the engine 2 and the electric motor 6 in the region below the rotational speed N1 are exactly the same in each control map, and the engine 2 and the electric motor in the rotational speed region higher than the rotational speed N1. The output area where torque is distributed to 6 increases or decreases in each control map.
These control maps are switched and used by control map switching control executed by the vehicle ECU 22. This control map switching control is started when the starter switch is operated by the driver and power is supplied to each ECU including the vehicle ECU 22, and is executed at a predetermined control cycle according to the flowchart shown in FIG.

When the process proceeds to step S1 in the first control cycle after the start of control, it is determined whether or not the value of the flag F1 is 1. The flag F1 having a value of 0 indicates that the control cycle is the first control cycle after the start of control, and is reset when the starter switch is turned off to end the control. Becomes 0.
Accordingly, the process proceeds to step S2 here, and the determination values K1 and K2 used to determine whether or not the SOC of the battery 18 is within the predetermined SOC range in the subsequent step are set, and K1 = It is set as SOC1 (for example, 40%) and K2 = SOC2 (for example, 50%), and the process proceeds to step S3.

In step S3, the value of the flag F1 is set to 1. In the next step S4, the SOC of the battery 18 detected by the battery ECU 28 is read.
In step S5, it is determined whether the SOC of the battery 18 read in step S4 is smaller than the determination value K1 set in step S2.
If the SOC of the battery 18 is greater than or equal to the determination value K1 set in step S2, the process proceeds to step S6, the value of the determination value K1 is again set to SOC1, the process proceeds to step S7, and the SOC of the battery 18 read in step S4 is read. Is greater than the determination value K2 set in step S2.

When the SOC of the battery 18 is equal to or less than the determination value K2 set in step S2, it is within the predetermined SOC range of the determination values K1 to K2, but in this case, the process proceeds to step S8 and the determination value K2 is set. After setting the value to SOC2 again, the process proceeds to step S9.
In step S9, it is determined from information from the engine ECU 24 whether or not the filter 44 is being regenerated. If the filter 44 is not being regenerated, the process proceeds to step S10 to select the control map A in FIG. When 44 is being reproduced, the process proceeds to step S11, the control map B of FIG. 3 is selected, and the current control cycle ends.

In the next control cycle, the process starts again from step S1, but the value of the flag F1 is already 1, and this time the process proceeds directly to step S4.
Then, after the current SOC of the battery 18 is read in step S4, the process proceeds to step S5 to determine again whether or not the SOC of the battery 18 is smaller than the determination value K1. Therefore, as long as the SOC of the battery 18 read in step S4 is within the predetermined SOC range of the determination values K1 to K2 in each control period, the control map A is selected in step S10 when the regeneration of the filter 44 is not performed. When the filter 44 is regenerated, the control map B is selected in step S11.

  On the other hand, if the SOC of the battery 18 decreases and it is determined in step S5 that it is smaller than the determination value K1, the process proceeds to step S12, and the value of the determination value K1 is set to SOC1 + a. When the SOC of the battery 18 is recovered and returned to the predetermined SOC range again, if SOC1 is used as the determination value K1, hunting is performed for switching the control map when the SOC of the battery 18 is in the vicinity of the determination value K1. Therefore, it is provided as a hysteresis for preventing this, for example, 2%.

When proceeding from step S12 to the next step S13, the control map C of FIG. 4 is selected and the current control cycle is terminated.
In the next control cycle, the process is started again from step S1, and after reading the current SOC of the battery 18 in step S4 as described above, the process proceeds to step S5 to check whether the SOC of the battery 18 is smaller than the determination value K1. It is determined again whether or not.

The determination value K1 used for the determination at this time is set to SOC1 + a in step S12 of the previous control cycle. Unless the SOC of the battery 18 read in step S4 in each control cycle is equal to or higher than SOC1 + a, the determination value K1 is passed through step S12. In step S13, the control map C is selected.
Then, when the SOC of the battery 18 is recovered and it is determined in step S5 that the SOC of the battery 18 is greater than or equal to the determination value K1 (= SOC1 + a), the process again proceeds to step S6. In step S6, the determination value K1 Return the value to SOC1.

  Further, when the SOC of the battery 18 rises and proceeds from step S6 to step S7, when it is determined that the SOC of the battery 18 read in step S4 is larger than the determination value K2, the process proceeds to step S14 and the determination value K2 is set. Let the value be SOC2-b. This b is also used for the same purpose as a used in step S12, and prevents hunting in switching of the control map when the SOC of the battery 18 decreases and returns to the predetermined SOC range again. It is provided as a hysteresis and is 3% here, for example.

  When the process proceeds from step S14 to the next step S15, it is determined from information from the engine ECU 24 whether or not the filter 44 is being regenerated. If the filter 44 is not being regenerated, the process proceeds to step S16 and the control of FIG. If the map D is selected and the filter 44 is being regenerated, the process proceeds to step S11 to select the control map B in FIG. 3, and the current control cycle is terminated.

In the next control cycle, the process is started again from step S1, and after reading the current SOC of the battery 18 in step S4 as described above, the process proceeds to step S5 to check whether the SOC of the battery 18 is smaller than the determination value K1. It is determined again whether or not.
The determination value K1 used for determination at this time is returned to SOC1, and as long as the SOC of the battery 18 read in step S4 in each control cycle is equal to or higher than SOC1, the process proceeds to step S7 through step S6 as described above. move on.

  In Step S7, it is determined whether or not the SOC of the battery 18 read in Step S4 is larger than the determination value K2, and the determination value K2 at this time is set to SOC2-b in Step S14 of the previous control cycle. As long as the SOC of the battery 18 read in step S4 is not lower than SOC2-b in each control cycle, it is determined whether or not the filter 44 is being regenerated in step S15 after step S14, and then the filter 44 is being regenerated. If not, the control map D is selected in step S16, and if the filter 44 is being regenerated, the control map B is selected in step S11.

Then, when the SOC of the battery 18 decreases and it is determined in step S7 that the SOC of the battery 18 is equal to or less than the determination value K2 (= SOC2-b), the process again proceeds to step S8, and in step S8, the determination value is reached. Return the value of K2 to SOC2.
By performing the control map switching control as described above, when the SOC of the battery 18 is within the predetermined SOC range of the determination values K1 to K2, if the filter 44 is not regenerated, the control map of FIG. A is selected.

  When the control map A in FIG. 2 is selected, the control region applied when the vehicle starts is a low rotation region lower than the rotation speed N1, and therefore the required torque and rotation set according to the depression amount of the accelerator pedal 30 The torque distribution between the engine 2 and the electric motor 6 differs depending on whether the operating point determined by the number of rotations of the electric motor 6 detected by the number sensor 36 is in the region M11 or the region E11 of FIG.

That is, when the operating point is within the region M11, the vehicle ECU 22 instructs the inverter ECU 26 so that the clutch 4 is disconnected and the output torque of the electric motor 6 becomes the required torque.
The inverter ECU 26 controls the inverter 20 according to the required torque set by the vehicle ECU 22, and the DC power of the battery 18 is converted into AC power by the inverter 20 and supplied to the electric motor 6. The electric motor 6 is operated by a motor when AC power is supplied to output a required torque. The output torque of the electric motor 6 is transmitted to the drive wheels 16 via the transmission 8 and the vehicle starts.

On the other hand, when the operating point is within the region E11, the vehicle ECU 22 instructs the inverter ECU 26 to output the upper limit torque Tm from the electric motor 6, and the upper limit torque Tm is insufficient with respect to the required torque. Is output from the engine 2 to the engine ECU 24.
At this time, since the rotational speed of the electric motor 6 is lower than the rotational speed of the engine 2, the vehicle ECU 22 controls the clutch 4 to a half-clutch state, and the torque transmitted from the clutch 4 to the transmission 8 becomes equal to the shortage. The engine ECU 24 is instructed to output such output torque from the engine 2.

Inverter ECU 26 controls inverter 20 as described above in accordance with an instruction from vehicle ECU 22, and motor 6 operates as a motor to output upper limit torque Tm.
Further, the engine ECU 24 controls the engine 2 so that the engine 2 outputs the torque instructed from the vehicle ECU 22, and the sum of the output torque from the engine 2 and the output torque from the electric motor 6 becomes a required torque to change the speed. The vehicle is transmitted to the machine 8 and the vehicle starts.

As described above, when the vehicle starts, the electric motor 6 is preferentially used to output up to the upper limit torque Tm, thereby reducing the usage ratio of the engine 2 having relatively low driving efficiency in the low rotation range. As a result, the fuel consumption can be improved and the vehicle can be smoothly started by the electric motor 6.
In addition, when the required torque cannot be obtained only with the output torque of the electric motor 6, the required torque is obtained by using the output torque of the engine 2 together. Good driving performance of the vehicle can be ensured.

When the vehicle starts and accelerates in this way and enters a traveling state, the vehicle ECU 22 determines the vehicle based on the depression amount of the accelerator pedal 30 detected by the accelerator pedal opening sensor 32 and the traveling speed detected by the vehicle speed sensor 34. Set the required torque required for driving.
When the rotational speed of the motor 6 rises and enters a region higher than the rotational speed N1, the vehicle ECU 22 has an operating point determined by the rotational speed of the motor 6 and the required torque detected by the rotational speed sensor 36 as shown in FIG. The control is switched depending on which of E12, M12 and E13.

When the operating point is within the region E12, the vehicle ECU 22 connects the clutch 4, instructs the inverter ECU 26 to set the output torque of the electric motor 6 to 0 N · m, and outputs the required torque from the engine 2. The engine ECU 24 is instructed.
The inverter ECU 26 controls the inverter 20, sets the output torque to 0 N · m in a state where the electric motor 6 is not operated by either the motor or the generator, and the engine ECU 24 controls the engine 2 so that the engine 2 outputs the required torque. Thus, the required torque output from the engine 2 is transmitted to the transmission 8.

When the operating point is within the region M12, the vehicle ECU 22 connects the clutch 4 to instruct the engine ECU 24 so that the output torque of the engine 2 becomes the allowable torque, and the engine 2 is in response to the required torque. The inverter ECU 26 is instructed so that the electric motor 6 outputs the shortage of the output torque.
The engine ECU 24 controls the engine 2 so that the output torque of the engine 2 becomes an allowable torque, and the inverter ECU 26 operates so that the electric motor 6 operates as a motor and the output torque becomes the torque instructed by the vehicle ECU 22. As a result, the sum of the output torque of the engine 2 and the output torque of the electric motor 6 is transmitted to the transmission 8 as a required torque.

Thus, in the region where the rotational speed of the electric motor 6 is higher than N1, the engine 2 is operated in a region where the NOx emission amount is relatively small by limiting the output torque of the engine 2 to be equal to or less than the allowable torque.
Furthermore, since the output torque of the engine 2 is limited to the allowable torque, the shortage from the required torque is compensated by the output torque of the electric motor 6, so that the required torque necessary for traveling of the vehicle is transmitted to the transmission 8. Thus, good driving performance of the vehicle can be ensured without causing torque shortage.

  When the operating point is within the region E13, the vehicle ECU 22 instructs the inverter ECU 26 to output the upper limit torque Tm from the electric motor 6 with the clutch 4 engaged, and the output torque of the engine 2 and the electric motor 6 The engine ECU 24 is instructed to output an output torque such that the sum of the output torque and the required torque is the required torque. Therefore, the output torque of the engine 2 instructed by the engine ECU 24 is larger than the allowable torque.

  The inverter ECU 26 controls the inverter 20 so that the electric motor 6 operates as a motor and outputs the upper limit torque Tm, and the engine ECU 24 controls the engine 2 so that the engine 2 outputs the output torque instructed by the vehicle ECU 22. As a result, the sum of the output torque of the engine 2 and the output torque of the electric motor 6 is transmitted to the transmission 8 as a required torque.

By performing such control, it is possible to reliably transmit the required torque to the transmission 8 even when a large required torque is temporarily required due to sudden acceleration or climbing of the vehicle. Thus, good driving performance of the vehicle can be ensured without causing torque shortage.
Further, when the SOC of the battery 18 is within the predetermined SOC range and the filter 44 is being regenerated by the control map switching control, the control map B of FIG. 3 is selected. Note that the control in the region below the rotation speed N1 and the effect obtained thereby are the same as the case where the regeneration of the filter 44 is not performed because the region setting in the control map is the same as described above. Is omitted. Further, the control of the engine 2 and the electric motor 6 performed by the engine ECU 24 and the inverter ECU 26 according to the torque distributed to the engine 2 and the electric motor 6 by the vehicle ECU 22 is performed in the same manner as the case where the regeneration of the filter 44 is not performed. It is omitted in the description.

The vehicle starts and accelerates to enter a traveling state, and the vehicle ECU 22 sets a required torque necessary for traveling of the vehicle as described above.
When the operating point determined by the rotational speed and the required torque of the electric motor 6 detected by the rotational speed sensor 36 is within the region E22 in the control map B of FIG. 3, the vehicle ECU 22 connects the clutch 4 and the electric motor 6 is instructed to the inverter ECU 26 to set the output torque of the engine 6 to 0 N · m, and the engine ECU 24 is instructed to output the required torque from the engine 2.

When the operating point is within the region M22, the vehicle ECU 22 connects the clutch 4 to instruct the engine ECU 24 so that the output torque of the engine 2 becomes an allowable torque, and the engine 2 is in response to the required torque. The inverter ECU 26 is instructed so that the electric motor 6 outputs the shortage of the output torque.
As described above, in the region where the rotational speed of the electric motor 6, that is, the rotational speed of the engine 2 is higher than N1, the output torque of the engine 2 is limited to an allowable torque or less, but at this time, the rotational speed of the engine 2 is lower than N2. In the rotation region, the engine 2 can output up to a larger allowable torque than when the filter 44 is not regenerated. For this reason, the exhaust temperature of the engine 2 rises, and it is possible to easily raise the temperature to the exhaust temperature necessary for the regeneration of the filter 44. Thus, an increase in fuel consumption for increasing the exhaust temperature and the regeneration of the filter 44 are achieved. It is possible to prevent deterioration in fuel consumption due to prolonged pulling and to prevent regeneration failure of the filter 44.

  Further, in the low rotation range, the output torque of the electric motor 6 is reduced by increasing the allowable torque of the engine 2 in this way. For this reason, although the power consumption of the battery 18 by the electric motor 6 decreases in the low rotation region, the engine has a smaller allowable torque than in the case where the regeneration of the filter 44 is not performed in the high rotation region where the rotation speed of the engine 2 is higher than N2. By limiting the output of 2, the output of the electric motor 6 increases correspondingly, and the power consumption of the battery 18 by the electric motor 6 increases.

Therefore, even if the electric power consumption of the electric motor 6 decreases in the low rotation region of the engine 2, the SOC of the battery 18 can be maintained within an appropriate range and deterioration of the battery 18 can be suppressed.
Also in this case, since the output torque of the engine 2 is limited to the allowable torque, the shortage from the required torque is compensated by the output torque of the electric motor 6, so that the transmission 8 is necessary for running the vehicle. The required torque is transmitted, and good driving performance of the vehicle can be ensured without causing torque shortage.

  Next, when the SOC of the battery 18 falls below the predetermined SOC range, the control map C of FIG. 4 is selected by the control map switching control described above regardless of whether the filter 44 is regenerated. As described above, the control in the region where the rotation speed is N1 or less and the effect obtained thereby are the same as when the SOC of the battery 18 is within the predetermined SOC range, and thus the description thereof is omitted.

Control of the engine 2 and the electric motor 6 performed by the engine ECU 24 and the inverter ECU 26 according to the torque distributed to the engine 2 and the electric motor 6 by the vehicle ECU 22 is performed in the same manner as when the SOC of the battery 18 is within the predetermined SOC range. Therefore, it is omitted in the following description.
The vehicle starts and accelerates to enter a traveling state, and the vehicle ECU 22 sets a required torque necessary for traveling of the vehicle as described above.

  When the operating point determined by the rotational speed and the required torque of the electric motor 6 detected by the rotational speed sensor 36 is within the region E32 in the control map C of FIG. 4, the vehicle ECU 22 connects the clutch 4 and the electric motor 6 is instructed to the inverter ECU 26 to set the output torque of the engine 6 to 0 N · m, and the engine ECU 24 is instructed to output the required torque from the engine 2.

When the operating point is within the region M32, the vehicle ECU 22 connects the clutch 4 and instructs the engine ECU 24 so that the output torque of the engine 2 becomes the maximum torque Te that can be output at the rotational speed. The inverter ECU 26 is instructed so that the electric motor 6 outputs an amount that the output torque of the engine 2 is insufficient with respect to the required torque.
As described above, when the SOC of the battery 18 is lower than the predetermined SOC range, in the rotation range higher than the rotation speed N1, the output torque of the engine 2 is allowed up to the maximum torque Te, whereby the torque is applied to the engine 2 in the control map C. The area E32 to be distributed is enlarged more than the area E12 of the control map A in FIG. 2, and as a result, the area M32 to which torque is distributed to the electric motor 6 is reduced more than the area M12 of the control map A in FIG.

Therefore, compared with the case where the SOC of the battery 18 is within the predetermined SOC range, the amount of energy consumed from the battery 18 by the electric motor 6 is reduced, and a further decrease in the SOC of the battery 18 can be suppressed.
Further, at this time, the output torque of the engine 2 is allowed up to the maximum torque Te, so that the output region where the torque is distributed to the engine 2 is maximized, and the output torque of the electric motor 6 is kept as small as possible. Can do. Thereby, the energy consumption from the battery 18 by the electric motor 6 can be suppressed to the maximum, and the decrease in the SOC of the battery 18 can be effectively suppressed.

If the vehicle decelerates during this time and regenerative braking is performed by the electric motor 6, the SOC of the battery 18 is recovered by energy recovery during deceleration and can be returned to the predetermined SOC range.
When the SOC of the battery 18 is lower than the predetermined SOC range, the output torque of the engine 2 is allowed up to the maximum torque in this way, so that the SOC of the battery 18 is within the predetermined SOC range. Assuming that it is not necessary to switch the control map in accordance with the necessity of regeneration of the filter 44, the torque is distributed using the common control map C regardless of the necessity of regeneration of the filter 44.

  When the SOC of the battery 18 is higher than the predetermined SOC range and the filter 44 is not regenerated, the control map D in FIG. 5 is selected by the control map switching control. As described above, the control in the region where the rotation speed is N1 or less and the effect obtained thereby are the same as when the SOC of the battery 18 is within the predetermined SOC range, and thus the description thereof is omitted. Control of the engine 2 and the electric motor 6 performed by the engine ECU 24 and the inverter ECU 26 according to the torque distributed to the engine 2 and the electric motor 6 by the vehicle ECU 22 is performed in the same manner as when the SOC of the battery 18 is within the predetermined SOC range. Therefore, it is omitted in the following description.

The vehicle starts and accelerates to enter a traveling state, and the vehicle ECU 22 sets a required torque necessary for traveling of the vehicle as described above.
When the operating point determined by the rotational speed and the required torque of the electric motor 6 detected by the rotational speed sensor 36 is within the region M41 in the control map D of FIG. 5, the clutch 4 is disconnected and the output of the electric motor 6 is output. The vehicle ECU 22 instructs the inverter ECU 26 so that the torque becomes the required torque.

On the other hand, when the operating point is within the region E41, the vehicle ECU 22 instructs the inverter ECU 26 to connect the clutch 4 and output the upper limit torque Tm from the electric motor 6, and the upper limit for the required torque. The vehicle ECU 22 instructs the engine ECU 24 to output from the engine 2 the shortage of the torque Tm.
As described above, when the SOC of the battery 18 is higher than the predetermined SOC range and the filter 44 is not regenerated, the output torque of the electric motor 6 is preferentially set in the rotation region higher than the rotation speed N1, and the maximum torque is set. By allowing up to Tm, the region M41 where the torque is distributed to the electric motor 6 in the region of relatively high rotational speed as shown in FIG. 5 is shown in FIG. 2 when the SOC of the battery 18 is within the predetermined SOC range. The area is larger than the area M12 in the control map.

As a result, compared with the case where the SOC of the battery 18 is within the predetermined SOC range, the amount of energy consumed from the battery 18 by the electric motor 6 is increased, and further increase in the SOC of the battery 18 is suppressed, and the SOC is charged to the predetermined charging rate. It becomes possible to return within the range.
Further, at this time, the output torque of the motor 6 is allowed up to the maximum torque Tm, so that the output region to which the torque of the motor 6 is distributed is expanded to the maximum, and the energy consumption from the battery 18 by the motor 6 is maximized. As a result, the increase in the SOC of the battery 18 can be effectively suppressed, and the SOC can be returned to the predetermined SOC range.

Further, even when the output torque of the electric motor 6 does not reach the maximum torque Tm, the output torque of the electric motor 6 is set preferentially as described above, and therefore depends on the output torque of the engine 2. Therefore, it becomes possible to positively consume the energy of the battery 18 by the electric motor 6, and to suppress the increase in the SOC of the battery 18.
On the other hand, when the SOC of battery 18 is higher than the predetermined SOC range and filter 44 is being regenerated, control map B in FIG. 3 is selected by control map switching control. This control map B is also used when the SOC of the battery 18 is within the predetermined SOC range and when the filter 44 is sanctioned. The contents of control by the vehicle ECU 22 based on the control map B are As described in.

  Since the output torque of the engine 2 is preferentially set by using the control map B when the regeneration of the filter 44 is being performed when the SOC of the battery 18 is higher than the predetermined SOC range, the electric motor 6 The output torque of the engine 2 can be set relatively large without being influenced by the output torque of the engine 44, and the exhaust temperature necessary for the regeneration of the filter 44 can be easily obtained.

  Further, the control map B of FIG. 3 is used for the regeneration of the filter 44 by expanding the region where the torque is distributed to the engine 2 in the low rotation region of the engine 2 as compared with the control map A of FIG. While making it easy to obtain the required exhaust temperature, an increase in the SOC accompanying a decrease in the output torque of the electric motor 6 in the low rotation region is prevented by expanding the region where the torque is distributed to the electric motor 6 in the high rotation region. I have to. Therefore, it is suitable for regeneration of the filter 44 in a state where the SOC of the battery 18 is higher than the predetermined SOC range, and the exhaust temperature required for regeneration of the filter 44 can be easily obtained, while the SOC of the battery 18 is Can be effectively suppressed.

Further, by sharing the control map with the regeneration of the filter 44 when the SOC of the battery 18 is within the predetermined SOC range, the control map switching control can be performed efficiently without complicating the control. The capacity of the storage device for storing the map can be reduced.
As described above, the control map showing the output region determined based on the rotation speed and the required torque of the electric motor 6 is switched according to the SOC of the battery 18 and the presence or absence of regeneration of the filter 44. It is possible to suppress the deterioration of the battery 18 so that the SOC of 18 does not deviate from the predetermined SOC range. Further, during regeneration of the filter 44, it is possible to easily raise the temperature to the exhaust temperature necessary for regeneration of the filter 44. Thus, the fuel consumption can be improved and the regeneration failure of the filter 44 can be prevented.

  Further, when the SOC of the battery 18 is within the predetermined SOC range and the filter 44 is not regenerated, in the region where the rotational speed of the electric motor 6, that is, the rotational speed of the engine 2 is higher than N1, during sudden start or climbing Except for special cases such as the above, the output torque of the engine 2 is limited to the allowable torque or less which is a torque region where the NOx emission amount is relatively small. Exhaust gas performance can be obtained.

Although the description of the control apparatus for a hybrid electric vehicle according to one embodiment of the present invention is finished above, the present invention is not limited to the above embodiment.
For example, in the above embodiment, the electric motor 6 is arranged between the clutch 4 and the transmission 8, but the arrangement of the electric motor 6 is not limited to this, and for example, between the engine 2 and the clutch 4. Similar effects can be obtained as long as the hybrid electric vehicle is capable of transmitting the driving force of the engine 2 and the driving force of the electric motor 6 to the driving wheels, such as a hybrid electric vehicle in which the electric motor 6 is disposed.

However, in the above embodiment, when the clutch 4 is disengaged and the driving wheel 16 is driven by the electric motor 6 alone, the driving torque of the engine 2 is simultaneously transmitted to the driving wheel, and the output torque of the engine 2 is minimized. Such control is necessary.
Further, when the SOC of the battery 18 is lower than the predetermined SOC range, the SOC of the battery 18 is within the predetermined SOC range by allowing the output of the engine 2 to the maximum torque in the region where the rotational speed of the electric motor 6 is higher than N1. Although the region where torque is distributed to the engine 2 is expanded as compared with a certain case, it is not always necessary to allow the maximum torque, and if the region where torque is distributed to the engine 2 is expanded. Good.

  Further, when the SOC of the battery 18 is higher than the predetermined SOC range, the output of the motor 6 is allowed to the maximum torque over a relatively high rotation region in the region where the rotation speed of the motor 6 is higher than N1, thereby The region in which the torque is distributed to the engine 2 is expanded as compared with the case where the SOC is within the predetermined SOC range, but it is not always necessary to allow the maximum torque, and the region in which the torque is distributed to the electric motor 6 is expanded. It only has to be adapted.

In the above embodiment, the rotational speed of the electric motor 6 detected by the rotational speed sensor 36 is used. However, the output rotational speed of the transmission 8 is detected and converted into the rotational speed of the electric motor 6 using the gear ratio. Alternatively, the rotational speed of the electric motor 6 may be obtained from an amount that changes according to the rotational speed of the electric motor 6.
In the above embodiment, the engine 2 is a diesel engine, but the engine type is not limited to this, and a gasoline engine or the like may be used.

Moreover, in the said embodiment, although the electric motor 6 was made into the permanent magnet type synchronous motor, the form of an electric motor is not restricted to this.
Furthermore, although the transmission 8 is an automatic transmission in the above embodiment, the type of transmission is not limited to this, and may be a continuously variable transmission, a manual transmission, or the like.

1 is an overall configuration diagram of a control apparatus for a hybrid electric vehicle according to an embodiment of the present invention. It is a figure which shows the control map A used in the control apparatus of FIG. It is a figure which shows the control map B used in the control apparatus of FIG. It is a figure which shows the control map C used in the control apparatus of FIG. It is a figure which shows the control map D used in the control apparatus of FIG. 3 is a flowchart of control map switching control executed in the control device of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hybrid electric vehicle 2 Engine 4 Clutch 6 Electric motor 16 Drive wheel 18 Battery 22 Vehicle ECU (control means)
24 Engine ECU (regeneration means)
28 Battery ECU (charging rate detection means)
36 Rotational speed sensor (Rotational speed detection means)
38 Exhaust passage 44 Filter

Claims (8)

The driving force of the engine and the driving force of the electric motor can be transmitted to the driving wheels of the vehicle, respectively, and the engine and the electric motor are controlled based on the required driving torque obtained according to the driving state of the vehicle. In a control device for a hybrid electric vehicle,
A battery for supplying electric power to the electric motor when the electric motor operates as a motor, and charging the electric power generated by the electric motor when the electric motor operates as a generator;
Charging rate detection means for detecting the charging rate of the battery;
A rotational speed detection means for detecting the rotational speed of the electric motor;
The required torque is distributed to the engine and the electric motor according to an output region determined based on the rotational speed of the electric motor detected by the rotational speed detection means and the required torque, and according to each distributed torque. Control means for controlling the engine and the electric motor,
In the first case where the charging rate detected by the charging rate detection unit is within a predetermined charging rate range, the control means sets the output torque of the engine at the rotational speed of the engine at that time. The output range is determined so that the output torque of the motor is limited to a predetermined allowable torque smaller than the maximum output torque, and when the engine output torque is insufficient with respect to the required torque, the shortage is set as the output torque of the motor. In the second case where the charging rate detected by the control unit is lower than the predetermined charging rate range, the region in which the torque is distributed to the electric motor in the output region is reduced compared to the first case, while the charging rate is reduced. In the third case where the charging rate detected by the detecting means is higher than the predetermined charging rate range, torque is distributed to the motor in the output region. Control apparatus for a hybrid electric vehicle, characterized in that the enlarged than the area of the first to be. A filter that collects particulates contained in the exhaust of the engine;
Regenerating means for incinerating the particulates collected and deposited on the filter to regenerate the filter;
In the first case, when the filter is regenerated by the regenerating unit, the control means increases the allowable torque in the low engine speed region when the filter is not regenerated. The control device for a hybrid electric vehicle according to claim 1, wherein the output region is determined so that the allowable torque decreases in a high rotation region of the engine.   In the third case, when the filter is not regenerated, the control means determines the output torque of the electric motor first and uses the rest as the output torque of the engine, while when regenerating the filter, 3. The control apparatus for a hybrid electric vehicle according to claim 2, wherein the output region is determined so that the output torque of the engine is determined first and the remainder is set to the output torque of the electric motor.   4. The output area when the filter is regenerated in the third case is the same as the output area when the filter is regenerated in the first case. The control apparatus of the hybrid electric vehicle described in 1.   In the second case, the control means allows the output torque of the engine to the maximum output torque of the engine at the engine speed at that time, and the engine output torque is insufficient with respect to the required torque. 2. The control apparatus for a hybrid electric vehicle according to claim 1, wherein the output region is determined so that the shortage is sometimes used as the output torque of the electric motor. A clutch capable of disconnecting transmission of driving force from the engine to the driving wheel in a state where transmission of driving force from the electric motor to the driving wheel is maintained;
In the third case, the control means allows the output torque of the motor to be the maximum torque that the motor can output at the rotation speed of the motor at that time, and when the required torque is less than or equal to the maximum torque, While the clutch is disconnected and the output torque of the electric motor is set as the required torque, when the maximum torque is insufficient with respect to the required torque, the clutch is connected to set the output torque of the electric motor as the required torque and 2. The control apparatus for a hybrid electric vehicle according to claim 1, wherein the output region is determined so that a shortage is an output torque of the engine.   In any case of the first to third cases, the control means determines the output torque of the electric motor first and sets the rest as the output torque of the engine when the vehicle starts. 2. The control apparatus for a hybrid electric vehicle according to claim 1, wherein the output region is determined so that the output of the electric motor is allowed up to a maximum torque that can be output from the electric motor at a rotation speed of the electric motor at that time. A clutch capable of disconnecting transmission of driving force from the engine to the driving wheel in a state where transmission of driving force from the electric motor to the driving wheel is maintained;
When the vehicle starts, the control means sets the clutch in a disengaged state when the required torque is equal to or less than the maximum torque that can be output from the electric motor at the rotation speed of the electric motor at that time. While controlling the electric motor to output, when the required torque is larger than the maximum torque, the clutch is connected so that the sum of the output torque of the motor and the torque output from the clutch becomes the required torque. The control apparatus for a hybrid electric vehicle according to claim 7, wherein the control unit controls an output torque of the engine and the electric motor.

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