JP2009040094A - Output control device and method for hybrid vehicle - Google Patents

Abstract

In a hybrid vehicle, energy efficiency in the entire vehicle is improved.
An output control apparatus for a hybrid vehicle includes, as power sources, an internal combustion engine and a motor generator, and coordinates having an output torque output from the internal combustion engine as a first axis and a rotational speed of the internal combustion engine as a second axis. An operation line selecting means for selecting one operation line having a small distance from the vehicle required power required by the vehicle among a plurality of operation lines having a fuel consumption rate within a predetermined range on the plane; Predetermined operating point determining means for determining a predetermined operating point as a target of the internal combustion engine on a coordinate plane based on the operating line; and target value determining means for determining a target torque or target rotational speed as a target of the motor generator; And second control means for controlling the motor generator.
[Selection] Figure 3

Description

  The present invention relates to a technical field of a hybrid vehicle output control apparatus and method for controlling an operation state of an internal combustion engine in a hybrid vehicle including an internal combustion engine and a motor generator as a power source.

  With respect to this type of hybrid vehicle output control device, in Patent Document 1, in a hybrid vehicle having a plurality of travel modes, an output control device that calculates an optimum target torque between the engine and the motor generator based on the required driving force. The technique regarding is disclosed.

  In addition, a technique related to an output control device that controls an engine operating point in consideration of power transmission efficiency of a power transmission system in a THS (Toyota Hybrid System) that changes an engine operating point in a power circulation mode has been proposed.

  Further, in Patent Document 2, in THS, during reverse running in which the engine power is generated by the first motor generator while traveling by the second motor generator, the operating point of the engine is determined according to the required driving force. A technique related to an output control device that changes the speed to the high rotation side is disclosed.

JP 2005-218221 A JP 2006-57617 A

  However, in the above-mentioned Patent Document 1 and the like, the operation line that minimizes the fuel consumption rate of the engine is selected as the operation line that minimizes the fuel consumption rate of the engine in a plurality of types of existing operation lines. In this case, the fuel consumption rate of the engine alone can be minimized, but there is a problem that it may become technically difficult to optimize the energy efficiency of the entire vehicle.

  Accordingly, the present invention has been made in view of the above-described problems, and it is an object of the present invention to provide a hybrid vehicle output control device and method for improving the energy efficiency of the entire vehicle in a hybrid vehicle. To do.

(Output control device for hybrid type vehicle)
In order to solve the above-described problems, an output control device for a hybrid vehicle according to the present invention is an output control device for a hybrid vehicle including an internal combustion engine and a motor generator as a power source, and the internal combustion engine outputs The vehicle is required among a plurality of operation lines in which a fuel consumption rate in the internal combustion engine exists within a predetermined range on a coordinate plane having the output torque to be operated as the first axis and the rotational speed of the internal combustion engine as the second axis. An operation line selection means for selecting one operation line having a small distance from the required vehicle power, and a predetermined operation point that is a target of the internal combustion engine on the coordinate plane based on the selected one operation line ( Predetermined operating point determining means for determining a target torque, a target rotational speed, etc.) and the internal combustion engine so as to approach the operating state indicated by the determined predetermined operating point A first control means for controlling, and a target for determining a target motor torque or a target motor rotational speed to be a target of the motor generator based on a difference between the determined predetermined operating point and a vehicle required power required by the vehicle Value determining means, and second control means for controlling the motor generator so as to approach the operation state indicated by the target motor torque or the target motor rotational speed.

  The hybrid vehicle output control apparatus according to the present invention includes an internal combustion engine and a motor generator as a power source. The “internal combustion engine” in the present invention is a general term for engines that convert combustion of fuel into motive power, but preferably refers to engines that use gasoline, diesel, LPG, or the like as fuel. The motor generator according to the present invention converts the electrical energy supplied from the battery into mechanical energy, thereby operating as an electric motor, and converts mechanical energy into electrical energy, for example, to supply power to a battery or the like. And a function of operating as a generator to be supplied. Two types of motor generators may be installed in advance: a motor generator mainly used as an electric motor (motor) and a motor generator mainly used as a generator (generator). In the hybrid vehicle according to the present invention including such an internal combustion engine and a motor generator, so-called parallel control is suitably performed in which the motor generator can appropriately assist the power of the internal combustion engine.

  In particular, according to the present invention, the fuel consumption rate of the internal combustion engine can be made better and lower than a predetermined level by the operation line selection means, and the vehicle that the entire vehicle requires from the internal combustion engine. One operation line that can be closest to the required power is selected and set. Here, the “fuel consumption rate” in the present invention is an index value representing the fuel injection amount per unit electric energy (for example, the unit is kWh) in the internal combustion engine. The output (ie, electric power) of the internal combustion engine is proportional to the product of the torque and the rotational speed of the internal combustion engine. Further, “vehicle required power” according to the present invention includes (i) drive power required for the drive shaft of the vehicle, and (ii) charge power (charge power) required by the battery to the internal combustion engine via the motor generator. And the power required by the entire vehicle for the internal combustion engine (that is, the product of the rotation speed and the torque).

  In other words, according to the present invention, the fuel consumption rate of the internal combustion engine can be made better and lower than a predetermined level by the operation line selection means, and the engine output power output from the internal combustion engine can be maximized. One operating line that can be brought to a high level is selected. This “one operation line” can prescribe the operation state of the internal combustion engine on the coordinate plane with the torque of the internal combustion engine and the rotational speed of the internal combustion engine as the first axis and the second axis, respectively. It can be represented by a line defined by a plurality of operating points set in association with the engine output value. The operation line is preferably a line obtained by connecting these preset operation points to each other. At this time, the operating points corresponding to the individual output values may be appropriately interpolated.

  Next, the predetermined operation point determination means determines a predetermined operation point such as a target torque and a target rotation speed, which is a target of the internal combustion engine on the coordinate plane, based on the selected one operation line. Subsequently, the internal combustion engine is controlled so as to realize the operation state indicated by the determined predetermined operation point under the control of the first control means. More specifically, the first control means determines an operating point on the operating line, and controls the internal combustion engine to an operating state defined by the determined operating point.

  Simultaneously or in succession, based on the difference between the predetermined operating point determined by the target value determination means and the required vehicle power required by the vehicle, the target motor torque or the target motor speed that is the target of the motor generator Is determined. Subsequently, under the control of the second control means, the motor generator is controlled so as to approach the operation state indicated by the target motor torque or the target motor rotation speed.

  As a comparative example, when another operation line that only minimizes the fuel consumption rate of the internal combustion engine is selected, the motor generator uses the rotational speed of the internal combustion engine (that is, a variable proportional to the vehicle speed) as a variable. The total amount (total amount) of assist power shared by the engine can make the fuel consumption rate of the internal combustion engine better than a predetermined level, and is the closest to the vehicle required power that the entire vehicle requires for the internal combustion engine. As compared with the case where one operation line capable of being selected is selected, the operation line becomes significantly larger. Therefore, in the comparative example, there are a plurality of types of operation lines that minimize the fuel consumption rate of the internal combustion engine.For internal combustion engines that exist, the fuel consumption rate of the internal combustion engine alone can be minimized. Optimizing the energy efficiency of the entire vehicle can be technically difficult.

  On the other hand, according to the present invention, the fuel consumption rate of the internal combustion engine can be made better than a predetermined level and minimized by the operation line selection means, and the entire vehicle can be compared with the internal combustion engine. One operation line that can be closest to the requested vehicle power is selected and set. In other words, the fuel consumption rate of the internal combustion engine can be made better and lower than a predetermined level, and at the same time, it is possible to make the engine output power output from the internal combustion engine the highest level. Is selected. In other words, the fuel consumption rate of the internal combustion engine can be made better than a predetermined level and minimized, the engine torque output from the internal combustion engine can be increased, and the rotation speed of the internal combustion engine can be increased. One operating line is selected.

  Therefore, since the ratio of the assist torque shared by the motor generator can be reduced as compared with the case of selecting another operation line that only minimizes the fuel consumption rate of the internal combustion engine, the assist power by the motor generator can be reduced. It is possible to reduce the discharge amount of the battery. As a result, it is possible to remarkably improve the ratio of the engine output power that bears the power required by the drive shaft, the so-called direct ratio.

  As a result of the above, there are a plurality of types of operation lines that minimize the fuel consumption rate of the internal combustion engine. In addition to reducing the fuel consumption rate of the internal combustion engine and improving the thermal efficiency of the internal combustion engine, The energy efficiency of the entire vehicle including the motor generator can be significantly improved and optimized.

  In an aspect of the hybrid vehicle output control apparatus according to the present invention, the operation line selection means increases the output power (product of the output torque and the rotation speed) output from the internal combustion engine from a standard power. Thus, the one operation line is selected.

  According to this aspect, it is possible to more significantly improve the ratio of the engine output power that bears the power required by the drive shaft, that is, the so-called direct ratio, based on comparison with the standard value. Here, the standard power may simply mean a power defined corresponding to another operation line that minimizes the fuel consumption rate of the internal combustion engine.

  In another aspect of the hybrid vehicle output control apparatus according to the present invention, the operation line selection means includes: (i) when the motor generator functions as an electric motor, the output torque is a vehicle request required by the vehicle. (Ii) When the motor generator functions as a generator, the one operation line is selected so that the output torque is greater than the vehicle required torque. select.

  According to this aspect, the case where the motor generator functions as an electric motor and the case where the motor generator functions as a generator are distinguished, and the one selected by comparing the output torque with the vehicle request torque required by the vehicle. Based on the operation line, the ratio of the engine output power to the power required by the drive shaft, the so-called direct ratio, can be improved with higher accuracy.

  In another aspect of the hybrid vehicle output control device according to the present invention, the hybrid vehicle further includes an operating point correcting means for correcting the predetermined operating point (target torque, target rotational speed, etc.), When the output power (the product of the output torque and the rotational speed) output from the internal combustion engine in the operating state indicated by the predetermined operating point decreases due to the determined target motor torque or the target motor rotational speed, The predetermined operating point (target torque, target rotational speed, etc.) is corrected so as to increase the output power.

  According to this aspect, the engine output power is required for the drive shaft while appropriately responding to a decrease in the power level of the operation state indicated by the predetermined operation point due to the target motor torque or the target motor rotation speed. It is possible to improve the ratio of carrying power, the so-called direct ratio, with higher accuracy.

  In another aspect of the hybrid vehicle output control apparatus according to the present invention, the operation line selecting means selects the one operation line based on a change in temperature of the internal combustion engine.

  According to this aspect, while appropriately responding to a change in the temperature of the internal combustion engine, based on the selected one operation line, the ratio of the engine output power that bears the power required by the drive shaft, the so-called direct ratio, is set. It is possible to improve with higher accuracy.

(Output control method for hybrid type vehicle)
In order to solve the above-mentioned problem, an output control method for a hybrid vehicle according to the present invention is an output control method in an output control device for a hybrid vehicle including an internal combustion engine and a motor generator as a power source, Among a plurality of operation lines for causing a fuel consumption rate in the internal combustion engine to exist within a predetermined range on a coordinate plane having an output torque output from the internal combustion engine as a first axis and a rotational speed of the internal combustion engine as a second axis, An operation line selection step of selecting one operation line having a small distance from the vehicle required power required by the vehicle, and a target of the internal combustion engine on the coordinate plane based on the selected one operation line A predetermined operating point determination step for determining a predetermined operating point (target torque, target rotational speed, etc.) and an operating state indicated by the determined predetermined operating point Thus, based on the first control step for controlling the internal combustion engine and the difference between the determined predetermined operating point and the required vehicle power required by the vehicle, the target torque or the target rotational speed that is the target of the motor generator And a second control step of controlling the motor generator so as to approach the operating state indicated by the target torque or the target rotational speed.

  According to the hybrid vehicle output control method of the present invention, it is possible to receive various benefits of the above-described embodiment of the hybrid vehicle output control device of the present invention.

  Incidentally, in response to the various aspects of the embodiment of the hybrid vehicle output control apparatus according to the present invention described above, the embodiment of the hybrid vehicle output control method according to the present invention also adopts various aspects. It is possible.

  According to the hybrid vehicle output control apparatus of the present invention, in an internal combustion engine in which there are a plurality of types of operation lines that minimize the fuel consumption rate of the internal combustion engine, the fuel consumption rate of the internal combustion engine is reduced. It is possible not only to improve the thermal efficiency of the vehicle, but also to significantly improve and optimize the energy efficiency of the entire vehicle including the battery and the motor generator.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
(1) Basic configuration of the embodiment
(1-1) Configuration of hybrid system
First, the configuration of the hybrid system 10 according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of the hybrid system 10 according to this embodiment.

  In FIG. 1, the hybrid system 10 includes a control unit 100, an engine 200, a motor generator MG1, a motor generator MG2, a power split mechanism 300, an inverter 400, a battery 500, a vehicle speed sensor 600, and an accelerator opening sensor 610. It is a system to control.

  The control unit 100 includes an operation line selection unit 110, an engine ECU 120, a motor ECU 130, and a storage unit 140, and controls the overall operation of the hybrid system 10, and is a control unit such as an ECU (Engine Controlling Unit). It functions as an example of the “internal combustion engine output control device for a hybrid vehicle” according to the invention.

  The operation line selection unit 110 selects an operation line of the engine 200.

  The engine ECU 120 is configured to be able to control the operating state of the engine 200 in accordance with the operating point defined by the target torque on the operating line of the engine 200 and the target rotational speed. It is an example of “first control means” or “predetermined operating point determination means” according to the present invention.

  The motor ECU 130 can control the operation state of the motor generators MG1 and MG2 corresponding to the operation point defined by the target motor torque and the target motor rotation speed in the motor generators MG1 and MG2. It is an example of “second control means” according to the present invention or “target value determination means” according to the present invention.

  The storage unit 140 is a storage medium having a non-volatile storage area configured with, for example, a ROM (Read Only Memory) and a volatile storage area configured with a RAM (Random Access Memory). In the storage unit 140, various predetermined control programs, a control map described later, and the like are stored in the nonvolatile area.

  The engine 200 is a gasoline engine as an example of the “internal combustion engine” according to the present invention, and functions as a main power source of the hybrid vehicle 20. The detailed configuration of the engine 200 will be described later.

  Motor generator MG1 is an example of the “motor generator” according to the present invention, and is configured to function as a generator for charging battery 500 or as an electric motor for assisting the driving force of engine 200.

  Motor generator MG2 is another example of the “motor generator” according to the present invention, and is configured to function as an electric motor for assisting the output of engine 200 or as a generator for charging battery 500.

  The motor generator MG1 and the motor generator MG2 are configured as, for example, a synchronous motor generator, and include a rotor having a plurality of permanent magnets on the outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. Prepare. However, other types of motor generators may be used.

  The power split mechanism 300 is a planetary gear mechanism including a sun gear, a planetary carrier, a pinion gear, and a ring gear (not shown). Among these gears, the rotation shaft of the sun gear on the inner periphery is connected to the motor generator MG1, and the rotation shaft of the ring gear on the outer periphery is connected to the motor generator MG2. The rotation shaft of the planetary carrier located between the sun gear and the ring gear is connected to the engine 200, and the rotation of the engine 200 is transmitted to the sun gear and the ring gear by the planetary carrier and further the pinion gear. Is configured to be divided into two systems. In the hybrid vehicle 20, the rotating shaft of the ring gear is connected to the transmission mechanism 21 in the hybrid vehicle 20, and the driving force is transmitted to the wheels 22 through the transmission mechanism 21.

  Inverter 400 converts DC power extracted from battery 500 into AC power and supplies it to motor generator MG1 and motor generator MG2, and also converts AC power generated by motor generator MG1 and motor generator MG2 into DC power. The battery 500 can be supplied.

  The battery 500 is a rechargeable storage battery configured to be able to function as a power source for driving the motor generator MG1 and the motor generator MG2. The battery 500 is provided with an SOC sensor 510 that detects the remaining capacity of the battery 500 and is electrically connected to the control unit 100.

  The vehicle speed sensor 600 is a sensor that detects the speed of the hybrid vehicle 20 and is electrically connected to the control unit 100.

  Here, with reference to FIG. 2, an example of a detailed configuration of the engine 200 that outputs power to the power split mechanism will be described together with its basic operation. FIG. 2 is a schematic diagram showing a cross section of the engine 200 and a system system of the engine according to the present embodiment.

In FIG. 3, the engine 200 causes the air-fuel mixture to explode in the cylinder 201 under the control of the engine ECU 120, and the reciprocating motion of the piston 203 generated according to the explosive force is cranked via the connection rod 204. This is converted into the rotational motion of the shaft 205. At this time, the air sucked from the outside passes through the intake pipe 206 and is mixed with the fuel injected from the injector 207 to become the aforementioned air-fuel mixture. Fuel is supplied to the injector 207 from the fuel tank 223 via the filter 224. A fuel sensor 225 is installed in the fuel tank 223. The air-fuel mixture burned in the cylinder 201 becomes exhaust gas, passes through the exhaust valve 209 that opens and closes in conjunction with opening and closing of the intake valve 208, and is exhausted through the exhaust pipe 210. A cleaner 211 is disposed in the intake pipe 206, and an air flow meter 212 and an intake air temperature sensor 213 are installed on the downstream side of the cleaner 211. A throttle position sensor 215 is electrically connected to a throttle valve 214 disposed on the downstream side of the air flow meter 212 in the intake pipe 206. Around the throttle valve 214, an accelerator position sensor 216 for detecting the amount of depression of the accelerator pedal 226 by the driver and a throttle valve motor 217 for driving the throttle valve 214 are also provided. A crank position sensor 218 that detects the rotational position of the crankshaft 205 is provided in the vicinity of the crankshaft 205. The cylinder block is provided with a knock sensor 219 and a water temperature sensor 220, and the exhaust pipe 210 is provided with a three-way catalyst 222 and an air-fuel ratio sensor 221.
(2) Operating principle of the embodiment
(2-1) Basic operation of hybrid system
In the hybrid system 10 of FIG. 1, the driving force distribution among the motor generator MG1 that mainly functions as a generator, the motor generator MG2 that mainly functions as an electric motor, and the engine 200 is an operation state control unit 100a and a power split mechanism 300. To control the traveling state of the hybrid vehicle 20. Below, operation | movement of the hybrid system 10 according to several situations is demonstrated.
(2-1-1) At startup
For example, when hybrid vehicle 20 is started, motor generator MG1 driven using the electric energy of battery 500 functions as an electric motor. With this power, the engine 200 is cranked and the engine 200 is started.
(2-1-2) When starting
At the time of departure, two types of modes can be adopted depending on the storage state of the battery 500. The storage state of battery 500 is grasped by operation state control unit 100a based on the output signal of SOC sensor 510. For example, during a normal start (that is, with a good SOC), it is not necessary to charge the battery 500 by the motor generator MG1, so the engine 200 is started only for warm-up, and the hybrid vehicle 20 The vehicle starts with the driving force of the generator MG2. On the other hand, when the state of charge is not good (that is, the SOC is lowered), motor generator MG1 functions as a generator by the power of engine 200, and battery 500 is charged.
(2-1-3) During light load driving
For example, when the vehicle is traveling at a low speed or on a gentle hill, the efficiency of the engine 200 is relatively poor, so the engine 200 is stopped and the hybrid vehicle 20 travels only with the driving force of the motor generator MG2. At this time, if the SOC is lowered, engine 200 starts to drive motor generator MG1, and battery 500 is charged by motor generator MG1.
(2-1-4) During normal driving
In an operation region where the efficiency of the engine 200 is relatively good, the hybrid vehicle 20 travels mainly by the power of the engine 200. At this time, the power of the engine 200 is divided into two systems by the power split mechanism 300, one is transmitted to the wheels 22 via the transmission mechanism 21, and the other is driven by the motor generator MG1 to generate power. Furthermore, motor generator MG2 is driven by the generated electric power, and the power of engine 200 is assisted by motor generator MG2. At this time, if the SOC is lowered, the output of engine 200 is increased, and a part of the electric power generated by motor generator MG1 is charged to battery 500.
(2-1-5) During braking
When deceleration is performed, the motor generator MG2 is rotated by the power transmitted from the wheels 22 to operate as a generator. Thereby, the kinetic energy of the wheel 22 is converted into electric energy, and so-called “regeneration” is performed in which the battery 500 is charged.
(2-2) Basic control operation of the engine in the embodiment
Next, a basic control operation of the engine 200 will be described.

The control unit 100 repeatedly calculates an engine request output, which is an output required for the engine 200, at a constant period. The engine ECU 120 acquires the accelerator opening and the vehicle speed based on the output signals of the throttle position sensor and the vehicle speed sensor 600, and corresponds to the accelerator opening and the vehicle speed with reference to a map recorded in the nonvolatile area of the storage unit 140. The obtained output shaft torque (torque to be output to the transmission mechanism 21) is obtained. Further, engine ECU 120 obtains the required power generation amount based on the output signal of SOC sensor 510. The engine required output is obtained by correcting the output shaft torque with reference to the required power generation amount and the required amounts of various auxiliary machines (A / C, power steering, etc.). It should be noted that the calculation method of the engine required output may be as executed in a known hybrid vehicle, and the details thereof may be variously changed as necessary.
(2-3) Overall Process for Controlling Engine Operating State (Target Revolution, etc.) Next, referring to FIGS. 3 and 4, the engine operating state (target rotation speed, etc.) according to this embodiment is determined. The overall process to be controlled will be described. FIG. 3 is a flowchart showing the flow of overall processing for controlling the operating state (target rotational speed and the like) of the engine according to the present embodiment. FIG. 4 is a graph (FIG. 4A) showing the relationship between the drive shaft required torque required for the drive shaft of the vehicle and the vehicle speed according to the present embodiment, the target engine speed and the target. It is the graph (Drawing 4 (b)) showing the relation between the operation line of the engine for determining torque, and the vehicles demand power required for an engine. It should be noted that the overall processing for controlling the engine operating state (target rotational speed, etc.) according to this embodiment is repeatedly executed by the control unit at a predetermined cycle such as several tens of microseconds or several microseconds. .

  As shown in FIG. 3, first, under the control of the control unit 100, (i) the drive shaft required torque required for the drive shaft of the vehicle, and (ii) the entire vehicle including the battery and the motor generator is an engine. The vehicle required power required for the vehicle is determined based on, for example, the accelerator opening and the vehicle speed (step S101). Here, “vehicle required power” according to the present embodiment includes (i) drive power required for the drive shaft of the vehicle, and (ii) charge power (charge) required by the battery to the internal combustion engine via the motor generator. Force), and (iii) power required by the entire vehicle for the internal combustion engine (that is, the product of the rotation speed and torque), including various types of loss power.

  Specifically, when the drive control routine is executed, the CPU (Central Processing Unit) of the control unit 100 firstly, the accelerator opening from the accelerator pedal position sensor, the vehicle speed from the vehicle speed sensor, the rotational speed of the engine 200, Motor generator MG1, MG2 rotation speed, charging or discharging required power, battery 500 input / output limitation, transmission gear ratio, engine 200 cooling water temperature, oil temperature of lubricating cooling oil from temperature sensor, motor generator MG1 Then, a process for acquiring data necessary for control of the carrier frequency of MG2 is executed. Based on the acquired accelerator opening Acc and the vehicle speed V, (i) the required torque of the drive shaft to be output to the ring gear shaft as the drive shaft connected to the drive wheel as the torque required for the vehicle Tr, (ii) charging power (charging power) required by the battery to the engine via the motor generator, and (iii) vehicle required power Pe required by the entire vehicle for the engine, including various loss powers It is determined. More specifically, the drive shaft required torque Tr is stored in the ROM 74 as a drive shaft required torque setting map by predetermining the relationship among the accelerator opening Acc, the vehicle speed V, and the drive shaft required torque Tr in the embodiment. Alternatively, when the accelerator opening Acc and the vehicle speed V are given, the corresponding drive shaft required torque Tr may be derived and set from the stored map. FIG. 4A shows an example of a drive shaft required torque setting map. The required vehicle power Pe required for the engine by the entire vehicle is (i) the set required torque Tr of the drive shaft multiplied by the rotational speed Nr of the ring gear shaft 32a, and (ii) the required charge or discharge power. And (iii) energy loss.

  Next, an engine operating line is determined under the control of the control unit 100 (step S102). As shown in FIG. 4B, the target engine speed Ne1 and target torque Te1 of the engine 200, which will be described later, are determined from the determined engine operating line and the vehicle required power Pe (ie, Ne1 × Te1). Is determined based on the intersection of the curve with a constant value. The details of the engine operating line determination method will be described later.

  Next, under the control of the control unit 100, the maximum discharge power (maximum discharge power) that can be output by the battery is calculated (step S103). Note that the charging power (charging power) required by the battery may be calculated. Specifically, under the control of the battery ECU that controls the charge / discharge state of the battery, the maximum discharge power (maximum discharge power) that the battery can output is the remaining capacity of the battery (SOC: State Of Charge), the battery Calculated based on temperature and the like.

  Next, under the control of the control unit 100, the discharge power (discharge power) that the battery actually outputs is calculated (step S104). Specifically, the discharge power (discharge power) that is actually output under the control of the battery ECU is calculated based on the remaining capacity (SOC) of the battery, the temperature of the battery, and the like.

  Next, under the control of the control unit 100, (i) the determined engine operating line, (ii) the vehicle required power required by the entire vehicle including the battery and the motor generator, and (iii) the battery Based on the assist power by the motor generator corresponding to the discharge power (discharge power) that is actually output, the operating point of the engine, that is, the target torque and target speed required for the engine are determined (step S105). Specifically, the target engine speed is calculated by the following equation (1).

(Target engine speed) =
{(Vehicle required power)-(Assist power)} / (Target engine torque)
(1)
Specifically, instructed to realize the target rotational speed “Ne1” and target torque “Te1” of the engine 200 determined under the control of the control unit 100 simultaneously with or before or after step S105 described above. An instruction command to be transmitted is transmitted to an engine ECU that controls the engine. Based on the received instruction command, the engine ECU 120 controls the intake air amount in the engine 200, controls the fuel injection amount so as to operate at the operating point indicated by the target rotational speed Ne1 and the target torque Te1, Various controls such as ignition timing control are performed.

  Next, under the control of the control unit 100, based on the determined target engine speed, the rotation speed of the ring gear shaft 32a, and the gear ratio of the power distribution and integration mechanism, the target motor speed of the motor generator, A target motor torque is determined (step S106).

Specifically, an instruction command for instructing to achieve the target motor rotational speed of the motor generator, which is determined under the control of the control unit 100, is transmitted to the inverter simultaneously with or before or after step S106 described above. Is done. Then, based on the received instruction command, the inverter performs switching control of the switching element of the inverter so that the motor generator is driven at an operating point indicated by the target motor rotation speed and the target motor torque.
(2-4) Engine operating line determination method
Next, with reference to FIG.5 and FIG.6, the detail of the determination method of the engine operating line based on this embodiment is demonstrated. FIG. 5 shows the relationship between the engine operating line for determining the target engine speed and target torque in the engine and the required vehicle power required by the entire vehicle for the engine according to this embodiment. 6 is a graph shown in FIG. 5A and FIG. 5B when charging is not required and when charging is required. FIG. 6 is a graph (FIG. 6 (a)) showing the relationship between the contour lines indicating the level of the fuel consumption rate of the engine and the engine operation line, and the fuel consumption rate of the engine according to this embodiment. It is the graph (FIG.6 (b)) which showed the relationship between the contour line which showed the height, the operation line of an engine, a drive shaft required torque, and the running resistance of a vehicle.

  In addition to FIG. 5 and FIG. 6, the graph in FIG. 8 to be described later shows an example of the control map used by the control unit to determine the operation line. An example of the first axis) is a coordinate plane in which the torque Te of the engine 200 is represented, and the horizontal axis (that is, an example of the “second axis” according to the present invention) is the rotational speed Ne of the engine 200. It is an example of a “coordinate plane”. This control map is stored in advance in a non-volatile area in the storage unit 100e of the control unit.

  On this control map, it is possible to represent the relationship between the engine torque Te and the engine speed Ne for various parameters. Among these, the equal output line is a relationship line between the engine torque Te and the engine speed Ne when the output value of the engine 200 is constant. In addition to FIG. 5 and FIG. 6, in the graph in FIG. 8 described later, only one equal output line is drawn for the sake of simplification, but actually there are a plurality of equal output lines. The book can be set and can be set more finely.

  As shown in FIG. 5 (a) and FIG. 6 (a), when there are multiple types of engine operation lines that can make the fuel consumption rate of the engine better than a predetermined level, Then, the operation line L1 that can bring the engine output power output from the engine to the highest level is selected to determine the operation line. Here, the “fuel consumption rate” according to the present embodiment is an index value representing the fuel injection amount per unit power amount (for example, the unit is “kWh”) in the internal combustion engine. The output (ie, electric power) of the internal combustion engine is proportional to the product of the torque and the rotational speed of the internal combustion engine. Specifically, as an example of a factor that affects the fuel consumption rate of the engine 200, that is, the thermal efficiency of the engine 200, the temperature of the cooling water of the engine 200 can be cited. Note that the engine ECU 120 acquires the coolant temperature of the engine 200 detected by the temperature sensor.

  That is, as shown in FIG. 6 (a), an operation line that can make the fuel consumption rate of the engine better than a predetermined level based on the contour lines that indicate the level of the fuel consumption rate of the engine, For example, when the operation lines L1, L2, and L3 exist, the engine output power output from the engine can be set to the highest level (that is, the engine torque output from the engine is increased and the engine speed is increased). The operating line L1 is selected. The relationship between the operation line in FIG. 5 and the like, the target engine speed and target torque in FIG. 5 and the like, and the operation line and the target engine speed and target torque in FIG. And the contour lines that indicate the level of fuel consumption of the engine, based on experimental, theoretical, empirical, simulation, etc., corresponding to engine control conditions, environmental conditions, design conditions, etc. It can be specifically defined.

  More specifically, as shown in FIGS. 5 (a) and 6 (a), the motor generator does not require charging from the engine, and the motor generator is based on the discharge power (discharge power) of the battery. When the assist power exists, the operation line L1 that can be closest to the vehicle required power that the entire vehicle requests from the engine may be selected.

  Therefore, as shown in FIG. 6 (b), the ratio of the assist torque shared by the motor generator is made lower than when the operation line L2 is selected (see the dotted arrow line in FIG. 6 (b)). Since the assist power generated by the motor generator can be reduced, the amount of battery discharge can be reduced. As a result, it is possible to remarkably improve the ratio of the engine output power that bears the power required by the drive shaft, the so-called direct ratio.

  As a result of the above, in an engine where there are multiple types of operation lines that minimize the fuel consumption rate of the engine, not only can the engine fuel consumption rate be reduced and the engine thermal efficiency improved, but also the battery and motor generator It is possible to significantly improve and optimize the energy efficiency of the entire vehicle including.

In substantially the same manner, as shown in FIGS. 5B and 6A, when the battery requests the engine to charge via the motor generator, the entire vehicle requests the engine. You may make it select the operation line L1 which can output larger engine output power compared with vehicle request | requirement power.
(3) Examination of actions and effects according to this embodiment
Next, with reference to FIG. 7, the operation and effect according to the present embodiment will be examined. FIG. 7 is a graph (FIG. 7A) showing the relationship between the engine operating line, the torque shared by the motor generator, and the torque shared by the engine, according to the present embodiment. 8 is a graph (FIG. 7B) showing a relationship between an engine operation line, a torque shared by a motor generator, and a torque shared by an engine according to a comparative example.

  As shown in FIG. 7A, according to the present embodiment, the fuel consumption rate of the engine can be made better than a predetermined level, and the vehicle required power that the entire vehicle requests from the engine. The operation line L1 that can be closest to is selected. In other words, the operation line L1 capable of bringing the engine output power output (to be output) by the engine to the highest level is selected. In other words, it is possible to make the fuel consumption rate of the engine better than a predetermined level, to minimize it, to increase the engine torque output from the engine, and to increase the engine speed. L1 is selected.

  As shown in the comparative example of FIG. 7B, when another operation line L0 that minimizes the fuel consumption rate of the engine is selected, the engine speed “Ne” (that is, the vehicle speed) The total amount (total amount) of assist power shared by the motor generator with a variable proportional to the engine power consumption rate shown in FIG. 7 (a) can be made better than a predetermined level. In addition, the operation line L1 that can be brought closest to the vehicle required power that the entire vehicle requests from the engine is significantly increased. Therefore, in the comparative example, the engine consumption rate of the engine can be minimized. For engines having a plurality of types of operation lines, the fuel consumption rate of the engine alone can be minimized. Optimizing energy efficiency can be technically difficult.

  On the other hand, according to the present embodiment, the fuel consumption rate of the engine can be made better than a predetermined level and minimized, and the vehicle power required by the entire vehicle to the engine can be maximized. An operation line L1 that can be approached is selected and set. In other words, the fuel consumption rate of the engine can be made better and lower than a predetermined level, and the engine output power output (to be output) by the engine can be made the highest level. Line L1 is selected. In other words, it is possible to make the fuel consumption rate of the engine better than a predetermined level, to minimize it, to increase the engine torque output from the engine, and to increase the engine speed. L1 is selected.

  Accordingly, as shown in FIG. 7 (a), when the operation line L0 that minimizes the fuel consumption rate of the engine is selected as the ratio of the assist torque shared by the motor generator (in FIG. 7 (b)). The assist power by the motor generator can be reduced, so that the amount of battery discharge can be reduced. As a result, it is possible to remarkably improve the ratio of the engine output power that bears the power required by the drive shaft, the so-called direct ratio.

As a result of the above, in an engine where there are multiple types of operation lines that minimize the fuel consumption rate of the engine, not only can the engine fuel consumption rate be reduced and the engine thermal efficiency improved, but also the battery and motor generator It is possible to significantly improve and optimize the energy efficiency of the entire vehicle including.
(4) Other embodiments
Next, with reference to FIG. 8, the details of the determination method of the engine operation line according to another embodiment will be described. FIG. 8 shows the relationship between the engine operation line for determining the target engine speed and target torque in the engine and the required vehicle power required by the entire vehicle for the engine according to another embodiment. It is a graph.

  As shown in FIG. 8, the engine output power output by the engine is set to the highest level among a plurality of types of engine operation lines capable of making the fuel consumption rate of the engine better than a predetermined level. After selecting the operation line L1 that can be operated and determining the operation line, the operating point of the engine may be corrected as follows.

  That is, when the motor generator does not require charging to the engine and there is assist power by the motor generator corresponding to the maximum discharge power (discharge power) that the battery can output, the entire vehicle On the operation line L1 that can be closest to the required vehicle power, the operating point of the engine that increases the engine output power output by the engine may be selected.

  Accordingly, as shown in FIG. 8, the assist torque ratio shared by the motor generator can be reduced more than when the battery is discharged to the maximum, and the assist power by the motor generator can be reduced. It is possible to effectively reduce the amount of discharge. As a result, it is possible to remarkably improve the ratio of the engine output power that bears the power required by the drive shaft, the so-called direct ratio.

  As a result of the above, in an engine where there are multiple types of operation lines that minimize the fuel consumption rate of the engine, not only can the engine fuel consumption rate be reduced and the engine thermal efficiency improved, but also the battery and motor generator It is possible to improve and optimize the energy efficiency of the entire vehicle including it more significantly.

  The present invention is not limited to the above-described embodiments, and may be implemented in various forms. For example, the present invention is not limited to gasoline, and may be applied to an output control device for a hybrid vehicle having various internal combustion engines that use a diesel engine or other fuel.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification, and a hybrid vehicle with such a change These output control devices and methods are also included in the technical scope of the present invention.

1 is a block diagram of a hybrid system 10 according to an embodiment of the present invention. It is the schematic diagram which showed the system system of the engine while showing the cross section of the engine 200 based on this embodiment. It is the flowchart which showed the flow of the whole process which controls the operation state (target rotation speed etc.) of an engine based on this embodiment. The graph (FIG. 4 (a)) showing the relationship between the drive shaft required torque required for the drive shaft of the vehicle and the vehicle speed according to the present embodiment, the target engine speed and the target torque are determined. 5 is a graph (FIG. 4B) showing the relationship between the engine operation line for the engine and the required vehicle power required for the engine. The relationship between the engine operating line for determining the target rotational speed and target torque in the engine and the required vehicle power required by the entire vehicle for the engine, when charging is not required, and charging 6 is a graph shown in FIG. 5A and FIG. 5B. The graph (FIG. 6 (a)) showing the relationship between the contour line indicating the level of the fuel consumption rate of the engine and the operation line of the engine, and the level of the fuel consumption rate of the engine according to this embodiment. It is the graph (FIG.6 (b)) which showed the relationship between a contour line, an engine operating line, a drive shaft request | requirement torque, and the running resistance of a vehicle. The graph (FIG. 7A) showing the relationship between the engine operation line, the torque shared by the motor generator, and the torque shared by the engine according to the present embodiment, and the engine according to the comparative example It is the graph (FIG.7 (b)) which showed the relationship between an operation line, the torque which a motor generator shares, and the torque which an engine shares. It is the graph which showed the relationship between the engine operating line for determining the target rotation speed and target torque in an engine, and the vehicle request | requirement power which the whole vehicle requests | requires with respect to an engine based on other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Hybrid system, 11 ... Hybrid system, 12 ... Hybrid system, 13 ... Hybrid system, 20 ... Hybrid vehicle, 21 ... Transmission mechanism, 22 ... Wheel, 30 ... Control map, 100 ... Control unit, 110 ... Operation line selection means , 120 ... engine ECU, 130 ... motor ECU, 140 ... storage unit, 200 ... engine, MG1 ... motor generator, MG2 ... motor generator, 300 ... power split mechanism, 400 ... inverter, 500 ... battery, 510 ... SOC sensor, 600 ... Vehicle speed sensor

Claims (6)

A hybrid vehicle output control device including an internal combustion engine and a motor generator as a power source,
Among the plurality of operation lines for causing the fuel consumption rate in the internal combustion engine to exist within a predetermined range on a coordinate plane having the output torque output from the internal combustion engine as the first axis and the rotation speed of the internal combustion engine as the second axis , An operation line selection means for selecting one operation line having a small distance from the vehicle required power required by the vehicle;
Predetermined operating point determining means for determining a predetermined operating point as a target of the internal combustion engine on the coordinate plane based on the selected one operating line;
First control means for controlling the internal combustion engine so as to approach the operating state indicated by the determined predetermined operating point;
Target value determining means for determining a target motor torque or a target motor rotation speed to be a target of the motor generator based on a difference between the determined predetermined operating point and a vehicle required power required by the vehicle;
Second control means for controlling the motor generator so as to approach an operation state indicated by the target motor torque or the target motor rotation speed;
An output control device for a hybrid vehicle, comprising:   2. The hybrid vehicle output control according to claim 1, wherein the operation line selection unit selects the one operation line so that an output power output from the internal combustion engine is increased from a standard power. apparatus.   The operation line selection means selects (i) the one operation line so that the output torque approaches a vehicle request torque required by the vehicle when the motor generator functions as an electric motor, and (ii) 3. The hybrid system according to claim 1, wherein when the motor generator functions as a generator, the one operation line is selected so that the output torque is larger than the vehicle required torque. 4. Vehicle output control device. Further comprising an operating point correcting means for correcting the predetermined operating point;
When the output power output from the internal combustion engine in the operating state indicated by the predetermined operating point decreases due to the determined target motor torque or target motor speed, the operating point correction means The hybrid vehicle output control apparatus according to any one of claims 1 to 3, wherein the predetermined operating point is corrected so as to increase the value.   5. The hybrid vehicle according to claim 1, wherein the operation line selection unit selects the one operation line based on a change in temperature of the internal combustion engine. 6. Output control device. An output control method in an output control device of a hybrid vehicle including an internal combustion engine and a motor generator as a power source,
Among the plurality of operation lines for causing the fuel consumption rate in the internal combustion engine to exist within a predetermined range on a coordinate plane having the output torque output from the internal combustion engine as the first axis and the rotation speed of the internal combustion engine as the second axis An operation line selection step of selecting one operation line having a small distance from the vehicle request power required by the vehicle;
A predetermined operating point determining step for determining a predetermined operating point as a target of the internal combustion engine on the coordinate plane based on the selected one operating line;
A first control step of controlling the internal combustion engine so as to approach the operating state indicated by the determined predetermined operating point;
A target value determining step for determining a target motor torque or a target motor rotation speed as a target of the motor generator based on a difference between the determined predetermined operating point and a vehicle required power required by the vehicle;
A second control step of controlling the motor generator so as to approach an operation state indicated by the target motor torque or the target motor rotation speed;
An output control method for a hybrid vehicle, comprising:

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