JP2018011428A - Vehicle - Google Patents

Abstract

The present invention suppresses a slow change in braking force with respect to a driver's expectation. When a braking force reduction condition is satisfied when the accelerator is off, a braking force reduction that controls the motor so that a smaller braking force acts on the vehicle than when the reduction condition is not satisfied. Execute control. Further, when the braking force reduction control is stopped by performing the first operation (operation of the driver who expects a rapid change in driving force) during the execution of the braking force reduction control, the braking force reduction control is being executed. The braking force when the braking force acting on the vehicle does not satisfy the reduction condition at a higher rate value than when the braking force reduction control is stopped by performing the second operation different from the first operation. The motor is controlled to change toward. [Selection] Figure 3

Description

  The present invention relates to an automobile, and more particularly, to an automobile provided with a motor for traveling.

  2. Description of the Related Art Conventionally, as this type of automobile, there has been proposed an automobile that includes a running motor and controls the motor so that braking force acts on the automobile when the accelerator is off (see, for example, Patent Document 1). In this vehicle, when the accelerator mode is off, when the eco mode switch is on, braking force reduction control is performed to reduce the braking force applied to the vehicle compared to when the eco mode switch is off. .

JP 2013-35370 A

  In such an automobile, when the braking force reduction control is stopped and the braking force applied to the vehicle is increased, the braking force is gradually increased at a relatively low rate value. However, in this case, the change in the braking force may be slow with respect to the driver's expectation. For example, when the eco-mode switch is turned off or when the shift position is changed from the drive range to the sequential range, the braking force reduction control is canceled by an operation that expects the driver to feel crisp driving (moderate feeling). In some cases, the change in braking force may be slower than the driver's expectation.

  The main object of the automobile of the present invention is to suppress a slow change in the braking force with respect to the driver's expectation when increasing the braking force when the accelerator is off.

  The automobile of the present invention has taken the following means in order to achieve the main object described above.

The automobile of the present invention
A motor capable of outputting power to a drive shaft connected to the axle;
A control device for controlling the motor;
A car equipped with
The controller is
When the braking force reduction condition is satisfied when the accelerator is off, braking force reduction control is performed to control the motor so that a smaller braking force acts on the vehicle than when the reduction condition is not satisfied. Run,
Further, the control device includes:
When the braking force reduction control is stopped by an operation of a driver who expects a rapid change in driving force during the execution of the braking force reduction control, the operation is performed during the execution of the braking force reduction control. The braking force acting on the vehicle changes toward the braking force when the reduction condition is not satisfied at a larger rate value than when the braking force reduction control is stopped by performing a different operation. Controlling the motor to
This is the gist.

  In the automobile of the present invention, when the braking force reduction condition is satisfied when the accelerator is off, the motor is controlled so that a smaller braking force is applied to the vehicle than when the reduction condition is not satisfied. Brake force reduction control is executed. Further, when the braking force reduction control is canceled due to the driver's operation expecting a rapid change in the driving force during the execution of the braking force reduction control, an operation different from the operation during the execution of the braking force reduction control is performed. The motor is adjusted so that the braking force acting on the vehicle changes toward the braking force when the reduction condition is not satisfied, at a larger rate value than when the braking force reduction control is stopped. Control. As a result, when the braking force reduction control is canceled due to a driver's operation that expects a rapid change in the driving force during execution of the braking force reduction control, the condition for reducing the braking force acting on the vehicle is satisfied. It is possible to change the braking force more quickly toward the braking force when not. Thereby, it can suppress that the change of braking force becomes slow with respect to a driver | operator's expectation. Here, the “operation of the driver who expects a rapid change in driving force” includes an operation of turning off the eco switch and an operation of setting the shift position to a sequential position. The “operation different from the operation of the driver who expects a rapid change in driving force” includes an operation of turning off the brake.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is a flowchart which shows an example of the rate value setting routine performed by HVECU70 of an Example. It is explanatory drawing which shows an example of the time change of the execution state of braking force reduction control, shift position SP, rate value R, request torque Td *, and torque command Tm2 *. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. It is a block diagram which shows the outline of a structure of the electric vehicle 220 of a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as “HVECU”). 70.

  The engine 22 is configured as an internal combustion engine that outputs power using gasoline or light oil as a fuel. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port. . The engine ECU 24 receives signals from various sensors necessary to control the operation of the engine 22, for example, a crank angle θcr from a crank position sensor that detects the rotational position of the crankshaft 26 of the engine 22 from an input port. ing. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via an output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23.

  The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of planetary gear 30 is connected to the rotor of motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 36 that is coupled to the drive wheels 39a and 39b via a differential gear 38. A crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28.

  The motor MG1 is configured as, for example, a synchronous generator motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator motor, and a rotor is connected to the drive shaft 36. Inverters 41 and 42 are connected to motors MG <b> 1 and MG <b> 2 and to battery 50 via power line 54. The motors MG1 and MG2 are driven to rotate by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The motor ECU 40 receives signals from various sensors necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 from rotational position detection sensors 43 and 44 that detect rotational positions of the rotors of the motors MG1 and MG2. , Θm2, etc. are input via the input port. From the motor ECU 40, switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 are output via an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44.

  The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the inverters 41 and 42 via the power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include a battery voltage Vb from a voltage sensor 51 a installed between terminals of the battery 50, a battery current Ib from a current sensor 51 b attached to an output terminal of the battery 50, and a battery 50. The battery temperature Tb from the temperature sensor 51c attached to can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the battery current Ib from the current sensor 51b. The storage ratio SOC is a ratio of the capacity of power that can be discharged from the battery 50 to the total capacity of the battery 50.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Here, the shift position SP includes a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position), a sequential position (S position), and the like. The S position is a position where the driving force when the accelerator is on and the braking force when the accelerator is off during traveling are changed according to the gear stage M of the virtual stepped transmission. Thereby, in the S position, it is possible to give the driver a feeling of shifting by a virtual stepped transmission. In the embodiment, a six-speed transmission is considered as a virtual stepped transmission. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88 The vehicle speed V can also be mentioned. Furthermore, an eco-switch signal from the eco-switch 90 that instructs the eco-mode that gives higher priority to fuel efficiency than the normal mode can be cited as the travel mode Md. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

In the hybrid vehicle 20 of the embodiment thus configured, the required driving force of the drive shaft 36 is set based on the accelerator opening Acc and the vehicle speed V, and the required power corresponding to the required driving force is output to the drive shaft 36. In addition, the engine 22 and the motors MG1, MG2 are controlled to operate. As operation modes of the engine 22 and the motors MG1, MG2, there are the following modes (1) to (3).
(1) Torque conversion operation mode: The engine 22 is operated and controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motors MG1 and MG2. (2) Charging / discharging operation mode: sum of required power and electric power necessary for charging / discharging of the battery 50. In this mode, the motor MG1 and MG2 are driven and controlled so that the required power is output to the drive shaft 36. The engine 22 is operated and controlled so that the power suitable for the engine 22 is output from the engine 22, and all or a part of the power output from the engine 22 is charged with the battery 50 by the planetary gear 30 and the motors MG1 and MG2. The motors MG1 and MG2 are driven so that the torque is converted by the motor and the required power is output to the drive shaft 36. Gosuru mode (3) motor drive mode: stop the operation of the engine 22, required power to drive control of the motor MG2 to be outputted to the drive shaft 36 mode

  In the hybrid vehicle 20 of the embodiment thus configured, the motor MG2 is controlled as follows when the accelerator is off during forward travel. In parallel with the control of motor MG2, switching control of a plurality of switching elements of inverter 41 is performed so that engine 22 is stopped and torque is not output from motor MG1 by cooperative control of HVECU 70, engine ECU 24, and motor ECU 40. To do.

  When the accelerator is off during forward traveling, first, a required torque Td * required for the vehicle (required for the drive shaft 36) is set based on the vehicle speed V, the shift position SP, and the braking force reduction flag Fbr. Here, the vehicle speed V is input as detected by the vehicle speed sensor 88. The braking force reduction flag Fbr is a flag indicating whether or not to reduce the braking force when the accelerator is off. The braking force reduction flag Fbr indicates the amount of depression of the brake pedal 85 based on the brake pedal position BP from the brake pedal position sensor 86 when the eco switch 90 is off (in normal mode) or the brake pedal 85 is on. Set to 0 when the off-threshold value is exceeded, or when the shift position SP from the shift position sensor 82 is a shift position different from the forward position (D position) (for example, at the sequential position (S position)). Is done. The braking force reduction flag Fbr is when the eco switch 90 is on and when the brake pedal 85 is off (the amount of depression of the brake pedal 85 based on the brake pedal position BP from the brake pedal position sensor 86 is less than or equal to the off threshold) When the shift position SP from the shift position sensor 82 is the forward position (D position), the value is set to 1. In the embodiment, the required torque Td * is stored in a ROM (not shown) as a required torque setting map in which the relationship among the vehicle speed V, the braking force reduction flag Fbr, the shift position SP, and the required torque Td * is determined in advance. When V, braking force reduction flag Fbr, and shift position SP are given, the corresponding required torque Td * is derived from this map and set.

  An example of the required torque setting map is shown in FIG. As shown in the figure, when the shift position SP is at the S position, the required torque Td * is set to be smaller as the speed is lower than when the gear M is at the lower speed, more specifically, at the lower speed. To do. When the shift position SP is at the S position, the braking force reduction flag Fbr has a value of 0. Further, when the shift position SP is the D position and the braking force reduction flag Fbr is 0, the required torque Td * is set to be the same as that at the S position when the gear stage M is the fourth speed stage. Further, when the braking force reduction flag Fbr is a value 1 when the shift position SP is the D position, the required torque is set to be larger than that when the shift speed M is the highest speed (6th speed in the embodiment) at the S position. Set Td *. When the required torque Td * is negative, it means that the braking torque is required for the vehicle (drive shaft 36). Thus, as shown in the figure, the required torque Td * is set to be larger when the braking force reduction flag Fbr is 1 than when the braking force reduction flag Fbr is 0 (smaller as braking force).

  When the required torque Td * is thus set, the torque command Tm2 * is set so that the torque command Tm2 * gradually changes at the rate value R toward the required torque Td *, and the motor MG2 is driven by the torque command Tm2 *. Thus, switching control of a plurality of switching elements of the inverter 42 is performed. When the required torque Td *, that is, the torque command Tm2 * of the motor MG2 is negative (when it is a braking torque), a negative torque, that is, a braking torque is output to the drive shaft 36 by regenerative driving of the motor MG2. By such control, when the braking force reduction flag Fbr is a value 1, the required torque Td *, that is, the torque command Tm2 * of the motor MG2 is gradually increased at the rate value R compared to when the braking force reduction flag Fbr is a value 0. The motor MG2 is controlled with a small braking force. Therefore, hereinafter, the control when the braking force reduction flag Fbr is 1 is referred to as “braking force reduction control”.

  Next, the setting of the rate value R when the braking force reduction flag Fbr changes from the value 1 to the value 0 will be described. FIG. 3 is a flowchart illustrating an example of a rate value setting routine executed by the HVECU 70 of the embodiment. This routine is executed when the braking force reduction flag Fbr changes from the value 1 to the value 0.

  When this routine is executed, the HVECU 70 determines whether the braking force reduction flag Fbr has a value of 0 due to an operation (hereinafter referred to as “first operation”) that expects the driver to quickly change the driving force. It is determined whether or not (step S100). Here, as the first operation, in the embodiment, among the operations by the driver in which the braking force reduction flag Fbr is set to the value 0, the operation to turn off the eco switch 90 and the shift position SP to the sequential position (S Switching to (position). The second operation different from the first operation described later includes an operation of turning off the brake pedal 85 among the operations by the driver in which the braking force reduction flag Fbr is set to 0.

  When it is determined that the braking force reduction flag Fbr has a value of 0 by the second operation, that is, it is determined that the braking force reduction control has been stopped by the second operation, the value R1 is set to the rate value R for changing the required torque Td *. (Positive value) is set (step S110), and it is determined that the braking force reduction flag Fbr has a value of 0 by the first operation, that is, the braking force reduction control has been stopped by performing the second operation. Sometimes, the rate value R is set to a value R2 greater than the value R1 (step S120), and this routine is terminated. Receiving the torque command Tm2 *, the motor ECU 24 performs switching control of the plurality of switching elements of the inverter 42 such that the motor MG2 is driven by the torque command Tm2 * that changes at the rate value R toward the required torque Td *.

  FIG. 4 shows an example of a time change of the execution state of the braking force reduction control, the shift position SP, the rate value R, the required torque Td *, and the torque command Tm2 *. In the figure, the alternate long and short dash line is an example of a time change of the torque command Tm2 * when the first operation is performed. A broken line is an example of a time change of the torque command Tm2 * when the second operation is performed. As shown in the drawing, the torque command Tm2 * when the braking force limit control is stopped due to the first operation being performed is more than the torque command Tm2 * when the braking force limit control is stopped due to the second operation being performed. It changes toward the required torque Td * at a large rate value. Thus, when the braking force limit control is stopped due to the first operation being performed, the rate value R (value R2) is larger than when the braking force limit control is stopped due to the second operation being performed. Thus, the negative torque that changes quickly and reaches the required torque Td * can be output from the motor MG2 to the drive shaft 36, and the change of the braking force can be suppressed from slowing with respect to the driver's expectation. it can. It should be noted that when the braking force limit control is stopped due to the second operation being performed, the rate value R (value R1) is smaller than when the braking force limit control is stopped due to the first operation being performed. A negative torque that changes relatively slowly and reaches the required torque Td * is output from the motor MG2 to the drive shaft 36, so that the driver can feel more secure.

  According to the hybrid vehicle 20 of the embodiment described above, when the braking force reduction condition is satisfied when the accelerator is off, a smaller braking force is applied to the vehicle than when the reduction condition is not satisfied. Thus, the braking force reduction control for controlling the motor MG2 is executed. Further, when the braking force reduction control is stopped by performing the first operation (operation of the driver who expects a rapid change in driving force) during the execution of the braking force reduction control, the braking force reduction control is being executed. As a result of the second operation being performed, the braking force acting on the vehicle changes toward the braking force when the reduction condition is not satisfied at a larger rate value than when the braking force reduction control is stopped. Since the motor MG2 is controlled as described above, it is possible to suppress a slow change in the braking force with respect to the driver's expectation.

  In the hybrid vehicle 20 of the embodiment, when the condition for reducing the braking force is satisfied, the motor MG2 outputs a negative torque to the drive shaft 36 to cause the braking force to act on the vehicle. By ringing, the negative torque via the planetary gear 30 and the negative torque from the motor MG2 may be output to the drive shaft 36 to cause the braking force to act on the vehicle.

  In the hybrid vehicle 20 of the embodiment, the engine ECU 24, the motor ECU 40, and the HVECU 70 are provided. However, the engine ECU 24, the motor ECU 40, and the HVECU 70 may be configured as a single electronic control unit.

  In the hybrid vehicle 20 of the embodiment, the engine 22 and the motor MG1 are connected to the drive shaft 36 connected to the drive wheels 39a and 39b via the planetary gear 30, and the motor MG2 is connected to the drive shaft 36. However, as shown in the modified hybrid vehicle 120 of FIG. 5, the motor MG is connected to the drive shaft 36 connected to the drive wheels 39a and 39b via the transmission 130 and the clutch 129 is attached to the rotation shaft of the motor MG. It is good also as a structure which connects the engine 22 via. Moreover, as shown in the electric vehicle 220 of the modification of FIG. 6, it is good also as a structure of the electric vehicle which connects the motor MG for driving | running | working to the drive shaft 36 connected with the drive wheels 39a and 39b. In other words, any configuration may be used as long as it includes a traveling motor.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor MG2 corresponds to a “motor”, and the HVECU 70, the engine ECU 24, and the motor ECU 40 correspond to a “control device”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the automobile manufacturing industry.

  20, 120 Hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 planetary gear, 36 drive shaft, 38 differential gear, 39a, 39b drive wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position sensor, 50 battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Battery electronic control unit (battery ECU), 54 Electric power Line, 70 hybrid electronic control unit (HV ECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position Deployment sensor, 85 brake pedal, 86 a brake pedal position sensor, 88 vehicle speed sensor, 90 eco switch, 129 the clutch, 130 transmission, 220 electric vehicle, MG, MG1, MG2 motor.

Claims (1)

A motor capable of outputting power to a drive shaft connected to the axle;
A control device for controlling the motor;
A car equipped with
The controller is
When the braking force reduction condition is satisfied when the accelerator is off, braking force reduction control is performed to control the motor so that a smaller braking force acts on the vehicle than when the reduction condition is not satisfied. Run,
Further, the control device includes:
When the braking force reduction control is stopped by an operation of a driver who expects a rapid change in driving force during the execution of the braking force reduction control, the operation is performed during the execution of the braking force reduction control. The braking force acting on the vehicle changes toward the braking force when the reduction condition is not satisfied at a larger rate value than when the braking force reduction control is stopped by performing a different operation. Controlling the motor to
Automobile.

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