JP5092423B2 - Vehicle and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the occurrence of an abnormal noise when a braking force of an electric motor is replaced with a braking force of an apparatus such as a hydraulic brake for imparting a braking force, and to maintain the driving quality in low-speed driving. <P>SOLUTION: After a vehicle speed V becomes lower than a threshold value Vref, a motor torque Tm2 is replaced with a braking torque Tb of the hydraulic brake so that a rate value is changed in the middle and the regenerative torque of a motor is replaced with the braking force by the hydraulic brake. Thus, the abnormal noise to be generated in a state of outputting a large regenerative torque from the motor when the vehicle speed V is a little smaller than the threshold value Vref, is suppressed, and the braking force is smoothly replaced, thereby excellently maintaining riding quality in low vehicle speed. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a vehicle and a control method thereof.

Conventionally, as this type of vehicle, there has been proposed a vehicle that sequentially replaces a braking force by regenerative control of an electric motor and a braking force by a hydraulic brake during braking (see, for example, Patent Document 1). In this vehicle, the braking force of the hydraulic brake is increased linearly and the braking force of the motor is decreased by the increased amount, so that the braking force of the motor is replaced with the braking force of the hydraulic brake without impairing the comfort in the vehicle. Yes.
JP 2006-232117 A

  As described above, in a vehicle in which a braking force is applied to the vehicle using both the electric motor and the hydraulic brake, the motor is regeneratively controlled to a low vehicle speed with a large braking torque in order to increase the energy efficiency of the vehicle. In order to maintain good riding comfort, the braking force by the motor is smoothly replaced with the braking force by the hydraulic brake, but when replacing the braking force by the motor with the braking force by the hydraulic brake, the noise caused by the regeneration control of the motor May occur. The occurrence of such abnormal noise gives the passenger a sense of incongruity.

  The vehicle of the present invention and the control method thereof suppress the generation of abnormal noise that may occur when replacing the braking force by an electric motor and the braking force by a device that applies a braking force such as a hydraulic brake, and reduce the riding comfort at low vehicle speeds. It aims to keep well.

  The vehicle and the control method thereof according to the present invention employ the following means in order to achieve the above-described object.

The vehicle of the present invention
An electric motor capable of outputting braking force to the axle;
Braking force applying means capable of applying braking force to the vehicle;
Vehicle speed detection means for detecting the vehicle speed;
Requested braking force setting means for setting a requested braking force required for the vehicle;
When the detected vehicle speed is equal to or higher than a predetermined vehicle speed, a predetermined braking force is output from the electric motor within a range of the set required braking force, and the electric motor and the electric motor are configured so that the set required braking force acts on the vehicle. The braking force applying means is controlled, and when the detected vehicle speed is less than the predetermined vehicle speed, the braking force is reduced to a value of 0 except for an abnormal noise generation region where abnormal noise is generated when the braking force is output from the electric motor. Braking time control means for controlling the electric motor and the braking force applying means so that power is output from the electric motor and the set required braking force acts on the vehicle;
It is a summary to provide.

In the vehicle of the present invention, when the vehicle speed is equal to or higher than the predetermined vehicle speed, the electric motor and the braking force are applied so that the predetermined braking force is output from the motor within the range of the required braking force required for the vehicle and the required braking force acts on the vehicle. Control means. Thereby, the required braking force can be applied to the vehicle by the braking force by the electric motor and the braking force by the braking force applying means. When the vehicle speed is less than the predetermined vehicle speed, a braking force that decreases to a value of 0 is output from the motor except for an abnormal noise generation region that generates abnormal noise when the braking force is output from the motor, and the required braking force is The electric motor and the braking force applying means are controlled so as to act on the motor. Thereby, the braking force by the electric motor and the braking force by the braking force applying means can be replaced without causing abnormal noise. Of course, since the braking force by the electric motor and the braking force by the braking force applying means can be replaced smoothly, the ride comfort of the occupant at a speed lower than the predetermined vehicle speed can be maintained well.

In such a vehicle of the present invention , the abnormal sound generation region may be a region of high braking speed and high braking force in a region below the predetermined vehicle speed.

In the vehicle of the present invention , the internal combustion engine is connected to a drive shaft connected to an axle, and is connected to the output shaft of the internal combustion engine so as to be rotatable independently of the drive shaft, with input and output of electric power and power. Power power input / output means for inputting / outputting power to / from the drive shaft and the output shaft, and power storage means capable of exchanging power with the power power input / output means and the electric motor. . In this case, the power motive power input / output means is connected to three axes of a generator capable of exchanging electric power with the power storage means, the drive shaft, the output shaft, and the rotating shaft of the generator. It can also be a means provided with three-axis type power input / output means for inputting / outputting power to / from the remaining shafts based on power input / output to / from any two axes.

The vehicle control method of the present invention includes:
A control method during braking of a vehicle comprising: an electric motor capable of outputting a braking force to an axle; a braking force applying means capable of applying a braking force to the vehicle; and a vehicle speed detecting means for detecting a vehicle speed,
When the detected vehicle speed is equal to or higher than a predetermined vehicle speed, a predetermined braking force is output from the electric motor within a range of the set required braking force, and the electric motor and the electric motor are configured so that the set required braking force acts on the vehicle. The braking force applying means is controlled, and when the detected vehicle speed is less than the predetermined vehicle speed, the braking force is reduced to a value of 0 except for an abnormal noise generation region where abnormal noise is generated when the braking force is output from the electric motor. Controlling the electric motor and the braking force applying means so that power is output from the electric motor and the set required braking force acts on the vehicle;
It is characterized by that.

In the vehicle control method of the present invention, when the vehicle speed is equal to or higher than the predetermined vehicle speed, the electric motor is configured so that the predetermined braking force is output from the electric motor and the required braking force acts on the vehicle within the range of the required braking force required for the vehicle. The braking force applying means is controlled. Thereby, the required braking force can be applied to the vehicle by the braking force by the electric motor and the braking force by the braking force applying means. When the vehicle speed is less than the predetermined vehicle speed, a braking force that decreases to a value of 0 is output from the motor except for an abnormal noise generation region that generates abnormal noise when the braking force is output from the motor, and the required braking force is The electric motor and the braking force applying means are controlled so as to act on the motor. Thereby, the braking force by the electric motor and the braking force by the braking force applying means can be replaced without causing abnormal noise. Of course, since the braking force by the electric motor and the braking force by the braking force applying means can be replaced smoothly, the ride comfort of the occupant at a speed lower than the predetermined vehicle speed can be maintained well.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as a first embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the first embodiment includes an engine 22, a three-shaft power distribution and integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, A motor MG1 capable of generating electricity connected to the distribution integration mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution integration mechanism 30, and a motor MG2 connected to the reduction gear 35 A brake actuator 92 for controlling the brakes of the drive wheels 39a and 39b and driven wheels (not shown), and a hybrid electronic control unit 70 for controlling the entire drive system of the vehicle.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as an engine ECU) that receives signals from various sensors that detect the operating state of the engine 22. ) 24 is subjected to operation control such as fuel injection control, ignition control, intake air amount adjustment control and the like. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 39a and 39b of the vehicle through the gear mechanism 37 and the differential gear 38.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. Further, the battery ECU 52 calculates the remaining capacity (SOC) based on the integrated value of the charging / discharging current detected by the current sensor in order to manage the battery 50, and calculates the remaining capacity (SOC) and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the above.

  The brake actuator 92 has a braking torque corresponding to the share of the brake in the braking force applied to the vehicle by the pressure (brake pressure) of the brake master cylinder 90 and the vehicle speed V generated in response to the depression of the brake pedal 85. The brake wheel cylinders 96a to 96d are adjusted so as to act on the driven wheels 39b and the driven wheels (not shown), and the braking torques are applied to the drive wheels 39a and 39b and the driven wheels regardless of the depression of the brake pedal 85. The hydraulic pressures of 96a to 96d can be adjusted. Hereinafter, a case where a braking force is applied to the drive wheels 39a and 39b and a driven wheel (not shown) by the operation of the brake actuator 92 is referred to as a hydraulic brake. The brake actuator 92 is controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 94. The brake ECU 94 inputs signals such as a wheel speed from a wheel speed sensor (not shown) attached to the drive wheels 39a and 39b and the driven wheel and a steering angle from a steering angle sensor (not shown) through a signal line (not shown). When the driver depresses the brake pedal 85, an anti-lock brake system function (ABS) that prevents any of the driving wheels 39a, 39b or the driven wheels from slipping due to locking, or when the driver depresses the accelerator pedal 83 Traction control (TRC) for preventing any one of the drive wheels 39a and 39b from slipping due to idling, posture holding control (VSC) for holding the posture while the vehicle is turning, and the like are also performed. The brake ECU 94 communicates with the hybrid electronic control unit 70, and controls the drive of the brake actuator 92 by a control signal from the hybrid electronic control unit 70, and the data regarding the state of the brake actuator 92 is used for the hybrid as necessary. Output to the electronic control unit 70.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and the engine ECU 24, the motor ECU 40, the battery ECU 52, the brake ECU 94, and various control signals and data. We are exchanging.

  The hybrid vehicle 20 of the first embodiment configured in this way is the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc corresponding to the amount of depression of the accelerator pedal 83 by the driver and the vehicle speed V. The engine 22, the motor MG1, and the motor MG2 are controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is 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 the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution and integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on.

  Next, the operation of the hybrid vehicle 20 of the first embodiment thus configured and the operation when the brake pedal 85 is depressed will be described. FIG. 2 is a flowchart showing an example of a braking control routine executed by the hybrid electronic control unit 70 when the brake pedal 85 is depressed. This routine is repeatedly executed every predetermined time (for example, every several msec). When the brake pedal 85 is depressed, in parallel with the braking time control routine of FIG. 2, the motor ECU 40 controls the motor MG1 so that the engine 22 operates independently at the idle speed Nidl without outputting torque from the motor MG1. Then, control of the engine 22 by the engine ECU 24 is executed. Since the control of the motor MG1 and the engine 22 does not form the core of the present invention, further detailed description is omitted.

  When the braking control routine is executed, the CPU 72 of the hybrid electronic control unit 70 firstly, the brake pedal position BP from the brake pedal position sensor 86, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Nm1 of the motors MG1 and MG2. , Nm2, etc., a process for inputting data necessary for control is executed (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do.

  When the data is thus input, the required braking torque to be output to the ring gear shaft 32a as the driving shaft connected to the driving wheels 39a, 39b as the braking torque required for the vehicle based on the input brake pedal position BP and the vehicle speed V. Tr * is set (step S110). In the first embodiment, the required braking torque Tr * is stored in the ROM 74 as a required braking torque setting map by predetermining the relationship among the brake pedal position BP, the vehicle speed V, and the required braking torque Tr *. When BP and vehicle speed V are given, the corresponding required braking torque Tr * is derived from the stored map and set. FIG. 3 shows an example of the required braking torque setting map.

  Subsequently, the input vehicle speed V is compared with a threshold value Vref (step S120). When the vehicle speed V is equal to or higher than the threshold value Vref, a torque obtained by dividing the required braking torque Tr * by the gear ratio Gr of the reduction gear 35 is set as a temporary motor torque Tm2tmp. While calculating (step S130), the smaller one of the calculated temporary motor torque Tm2tmp and maximum regenerative torque Tset1 is set as the torque command Tm2 * of the motor MG2 (step S140). Here, the threshold value Vref is a vehicle speed at which a replacement operation for smoothly replacing the regenerative torque by the motor MG2 with the braking force by the hydraulic brake is started. For example, 15 km / h, 17 km / h, or the like can be used. The maximum regenerative torque Tset1 is the maximum torque that can efficiently regenerate the kinetic energy of the vehicle when the regenerative control of the motor MG2 is performed, and can be set according to the performance of the motor MG2. As described above, when the vehicle speed V is equal to or higher than the threshold value Vref, the kinetic energy of the vehicle is efficiently regenerated by setting the maximum regenerative torque Tset1 to the torque command Tm2 * of the motor MG2 within the range of the required braking torque Tr *. Can do.

  When the torque command Tm2 * of the motor MG2 is set in this way, a brake required for the hydraulic brake when the torque command Tm2 * multiplied by the gear ratio Gr is subtracted from the required braking torque Tr * is converted into the ring gear shaft 32a. The torque Tb * is set (step S200), the torque command Tm2 * of the motor MG2 is transmitted to the motor ECU 40, and the brake torque Tb * is transmitted to the brake ECU 94 (step S210), and this routine is terminated. The motor ECU 40 that has received the torque command Tm2 * performs switching control of the switching element of the inverter 42 so that torque corresponding to the torque command Tm2 * is output from the motor MG2. The brake ECU 94 that has received the brake torque Tb * drives and controls the brake actuator 92 so that the braking force by the brake wheel cylinders 96a to 96d becomes a torque corresponding to the brake torque Tb * when converted to the ring gear shaft 32a. Thereby, the braking torque which becomes the required braking torque Tr * when converted to the ring gear shaft 32a by the torque output from the motor MG2 and the braking force by the brake wheel cylinders 96a to 96d can be applied to the vehicle. FIG. 4 shows an example of a collinear diagram for dynamically explaining the rotating elements of the power distribution and integration mechanism 30 in this state.

  If it is determined in step S120 that the vehicle speed V is less than the threshold value Vref, the previously set torque command Tm2 * of the motor MG2 is not 0 in order to smoothly replace the regenerative torque by the motor MG2 with the braking force by the hydraulic brake. (S150), it is determined whether or not the previously set torque command Tm2 * of the motor MG2 is greater than or equal to the regenerative torque Tset2 (step S170), and the previous torque command Tm2 * is greater than or equal to the regenerative torque Tset2. Sometimes, the value obtained by subtracting the rate value Trt1 from the previous torque command Tm2 * is set as the torque command Tm2 * of the current motor MG2 (step S160), and the brake torque Tb * is set using the set torque command Tm2 *. To execute the process of transmitting the set value (steps S200 and S210) To end the routine. On the other hand, when the previous torque command Tm2 * is less than the regenerative torque Tset2, a value obtained by subtracting a rate value Trt2 (Trt1 <Trt2) larger than the rate value Trt1 from the previous torque command Tm2 * is set as the temporary motor torque Tm2tmp. (Step S180) The larger one of the set temporary motor torque Tm2tmp and the value 0 as the regenerative torque is set as the current torque command Tm2 * of the motor MG2 (Step S190), and the set torque command Tm2 * is used. Processing for setting the brake torque Tb * and transmitting the set value (steps S200 and S210) is executed, and this routine is terminated. Here, the regenerative torque Tset2 is a torque that changes the degree of reduction of the regenerative torque of the motor MG2 when the regenerative torque by the motor MG2 is replaced with a braking force by the hydraulic brake, and is smaller than the maximum regenerative torque Tset1 and larger than 0. And can be determined by the performance of the motor MG2. The rate values Trt1 and Trt2 are the degree of reduction in the regenerative torque of the motor MG2 when the regenerative torque by the motor MG2 is replaced with the braking force by the hydraulic brake, and are set so that Trt1 <Trt2 as described above. . As a result, the regenerative torque of the motor MG2 decreases relatively gently by the rate value Trt1, and then decreases relatively rapidly by the rate value Trt2. In step S190, the larger one of the temporary motor torque Tm2tmp and the value 0 as the regenerative torque is set as the torque command Tm2 * of the motor MG2. The torque command Tm2 * of the motor MG2 is negative torque, that is, driving This is to prevent the torque from being set. If the torque command Tm2 * is less than the regenerative torque Tset2 and the braking time control routine is repeatedly executed to set the value 0 to the torque command Tm2 * of the motor MG2 in step S190, the previous torque is set in step S150. It is determined that the command Tm2 * is a value of 0, the process of setting the brake torque Tb * using the torque command Tm2 * of the value 0 and transmitting the set value (steps S200 and S210) is executed, and this routine is terminated. To do.

  FIG. 5 shows the time change of the vehicle speed V when the regenerative torque by the motor MG2 is replaced with the braking force by the hydraulic brake, the torque Tm2 of the motor MG2, and the brake torque Tb by the hydraulic brake when converted to the ring gear shaft 32a. It is explanatory drawing which shows this typically. In FIG. 5, the maximum regenerative torque Tset1 is output from the motor MG2 until the vehicle speed V reaches the threshold value Vref, and the brake torque Tb is output from the hydraulic brake so that the required braking torque Tr * acts when converted to the ring gear shaft 32a. Has been. At time T11 when the vehicle speed V reaches the threshold value Vref, replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake by the rate value Trt1 is started, and when the torque Tm2 of the motor MG2 reaches the regenerative torque Tset2, the motor MG2 The rate value Trt1 as the degree of reduction when the regenerative torque is replaced with the braking force by the hydraulic brake is changed to a larger value Trt2, and the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake is continued. Then, at time T13 when the torque Tm2 of the motor MG2 becomes 0, the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake is completed. Thus, by changing the rate value during the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake, a state in which the motor MG2 outputs a large regenerative torque at a vehicle speed slightly lower than the threshold value Vref. Can be avoided. In general, when a large regenerative torque is output from the motor MG2 at a vehicle speed V slightly lower than the threshold Vref, an abnormal noise called regenerative noise is generated from the motor MG2, but the regenerative torque of the motor MG2 is replaced with a braking force by a hydraulic brake. The occurrence of this abnormal noise can be suppressed by changing the rate value during the period.

  According to the hybrid vehicle 20 of the first embodiment described above, the degree of decrease in the regenerative torque of the motor MG2 is larger than the rate value Trt1 during the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake. By changing to the rate value Trt2, it is possible to suppress the generation of abnormal noise from the motor MG2 that may occur in a state where the vehicle speed V outputs a large regenerative torque from the motor MG2 at a vehicle speed slightly lower than the threshold value Vref. Of course, since the regenerative torque of the motor MG2 is gradually replaced with the braking force by the hydraulic brake using the rate values Trt1, Trt2, the regenerative torque of the motor MG2 can be smoothly replaced with the braking force by the hydraulic brake. It is possible to satisfactorily maintain the riding comfort when replacing the regenerative torque of the motor MG2 with the braking force by the hydraulic brake at the vehicle speed. Further, when the vehicle speed V is equal to or higher than the threshold value Vref, the motor MG2 is regeneratively controlled by the maximum regenerative torque Tset1, so that the kinetic energy of the vehicle can be efficiently regenerated and the fuel consumption of the vehicle can be improved.

  In the hybrid vehicle 20 of the first embodiment, the degree of decrease in the regenerative torque of the motor MG2 is changed from the rate value Trt1 to a larger rate value Trt2 during the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake. However, the degree of decrease in the regenerative torque of the motor MG2 may be changed from the rate value Trt3 to a smaller rate value Trt4 during the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake. Good. In this case, the rate value Trt2 of the first embodiment may be used as the rate value Trt3 and the rate value Trt1 may be used as the rate value Trt4. FIG. 6 shows an example schematically showing a time change of the vehicle speed V, the torque Tm2 of the motor MG2, and the brake torque Tb due to the hydraulic brake when converted into the ring gear shaft 32a. Even in this case, by changing the rate value during the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake, the vehicle speed V outputs a large regenerative torque from the motor MG2 at a vehicle speed slightly lower than the threshold value Vref. Therefore, the generation of abnormal noise from the motor MG2 that can occur when the vehicle speed V is a vehicle speed slightly lower than the threshold value Vref and a large regenerative torque is output from the motor MG2 can be suppressed, and the regeneration of the motor MG2 can be suppressed. The torque can be smoothly replaced with the braking force by the hydraulic brake.

  Next, a hybrid vehicle 20B as a second embodiment of the present invention will be described. The hybrid vehicle 20B of the second embodiment has the same hardware configuration as the hybrid vehicle 20 of the first embodiment described with reference to FIG. Therefore, in order to avoid redundant description, detailed description of the hardware configuration of the hybrid vehicle 20B of the second embodiment is omitted.

  In the hybrid vehicle 20B of the second embodiment, the braking time control routine of FIG. 7 is executed instead of the braking time control routine of FIG. The processing of steps S300 to S340 and the processing of steps S400 and S410 of this braking time control routine are the same as the processing of steps S100 to S140 and the processing of steps S200 and S210 of the braking time control routine of FIG. Therefore, in the second embodiment, only the processing after the vehicle speed V reaches less than the threshold value Vref will be described in order to avoid redundant description.

  If it is determined in step S320 that the vehicle speed V is less than the threshold value Vref, the previously set torque command Tm2 * of the motor MG2 is regenerated torque Tset3 in order to smoothly replace the regenerative torque by the motor MG2 with the braking force by the hydraulic brake. It is determined whether or not it is above (step S350), and when the previous torque command Tm2 * is equal to or higher than the regenerative torque Tset3, a value obtained by subtracting the rate value Trt from the previous torque command Tm2 * is set as the temporary motor torque Tm2tmp. At the same time (step S370), the larger of the set temporary motor torque Tm2tmp and the value 0 as the regenerative torque is set as the torque command Tm2 * of the current motor MG2 (step S380), and the set torque command Tm2 * is used. Set the brake torque Tb * Perform transmits the processing (step S400, S410) and ends this routine. Here, the regenerative torque Tset3 is a torque for temporarily stopping the decrease of the regenerative torque of the motor MG2, and is set to a level that does not cause abnormal noise from the motor MG2 when the vehicle speed is slightly smaller than the threshold value Vref. be able to.

  On the other hand, when the previous torque command Tm2 * is less than the regenerative torque Tset3, a predetermined time (for example, 0.1 seconds, 0.2 seconds, 0.3 seconds, etc.) after the previous torque command Tm2 * has become less than the regenerative torque Tset3. ) It is determined whether or not it has elapsed (step S360). Until the predetermined time has elapsed, the torque command Tm2 * of the motor MG2 is not reduced by the rate value Trt, and the brake torque Tb is used using the torque command Tm2 * that is not changed. The process of setting * and transmitting the set value (steps S400 and S410) is executed, and this routine is terminated. When a predetermined time elapses after the previous torque command Tm2 * reaches less than the regenerative torque Tset3, a value obtained by subtracting the rate value Trt from the previous torque command Tm2 * is set as the temporary motor torque Tm2tmp (step S370). The larger of the set temporary motor torque Tm2tmp and the value 0 as the regenerative torque is set as the torque command Tm2 * of the current motor MG2 (step S380), and the brake torque Tb * is set using the set torque command Tm2 *. Processing for setting and transmitting the set value (steps S400 and S410) is executed, and this routine is terminated.

  FIG. 8 shows the brake by the hydraulic brake when converted to the vehicle speed V, the torque Tm2 of the motor MG2 and the ring gear shaft 32a when the regenerative torque by the motor MG2 is replaced with the braking force by the hydraulic brake by the control routine at the time of braking of the second embodiment. It is explanatory drawing which shows the time change of torque Tb typically. In FIG. 8, until the vehicle speed V reaches the threshold value Vref, the maximum regenerative torque Tset1 is output from the motor MG2, and the brake torque Tb is output from the hydraulic brake so that the required braking torque Tr * acts when converted to the ring gear shaft 32a. Has been. At time T21 when the vehicle speed V reaches the threshold value Vref, replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake by the rate value Trt is started, and when the torque Tm2 of the motor MG2 reaches the regenerative torque Tset3, The replacement of the regenerative torque with the braking force by the hydraulic brake is temporarily stopped. Then, the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake by the rate value Trt is resumed at a time T23 when a predetermined time has elapsed from the time T22, and the motor MG2 is turned on at a time T24 when the torque Tm2 of the motor MG2 becomes zero. Complete replacement of regenerative torque with braking force by hydraulic brake. As described above, by stepwise replacing the regenerative torque of the motor MG2 with the braking force by the hydraulic brake, the motor that can be generated in a state where the motor MG2 outputs a large regenerative torque at a vehicle speed slightly lower than the threshold value Vref. Generation of abnormal noise from MG2 can be suppressed.

  According to the hybrid vehicle 20B of the second embodiment described above, by replacing the regenerative torque of the motor MG2 with the braking force by the hydraulic brake in stages, the vehicle speed V is reduced from the motor MG2 at a vehicle speed slightly lower than the threshold value Vref. Generation of abnormal noise from the motor MG2 that can occur in a state where a large regenerative torque is output can be suppressed. Of course, since the regenerative torque of the motor MG2 is gradually replaced with the braking force by the hydraulic brake using the rate values Trt1, Trt2, the regenerative torque of the motor MG2 can be smoothly replaced with the braking force by the hydraulic brake. It is possible to satisfactorily maintain the riding comfort when replacing the regenerative torque of the motor MG2 with the braking force by the hydraulic brake at the vehicle speed. Further, when the vehicle speed V is equal to or higher than the threshold value Vref, the motor MG2 is regeneratively controlled by the maximum regenerative torque Tset1, so that the kinetic energy of the vehicle can be efficiently regenerated and the fuel consumption of the vehicle can be improved.

  In the hybrid vehicle 20B of the second embodiment, the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake is performed stepwise using the same rate value Trt. However, the hydraulic brake of the regenerative torque of the motor MG2 is used. The replacement to the braking force by may be performed step by step using different rate values.

  In the hybrid vehicle 20B of the second embodiment, the regenerative torque of the motor MG2 is replaced with the braking force by the hydraulic brake over two stages using the same rate value Trt, but the regenerative torque of the motor MG2 is The replacement with the braking force by the hydraulic brake may be performed over three stages or more using the same rate value Trt.

  In both the braking control by the hybrid vehicle 20 of the first embodiment and the braking control by the hybrid vehicle 20B of the second embodiment, the vehicle speed V outputs a large regenerative torque from the motor MG2 at a vehicle speed slightly lower than the threshold value Vref. Since the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake is smoothly performed while suppressing the occurrence of abnormal noise from the motor MG2 that may occur, the high vehicle speed and the high regenerative speed in a range where the vehicle speed V is smaller than the threshold value Vref. It can be said that the control of smoothly performing the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake while avoiding the region where the noise of the torque MG2 is generated. Thus, it is sufficient to avoid the region where abnormal noise is generated from the motor MG2, and to smoothly replace the regenerative torque of the motor MG2 with the braking force by the hydraulic brake. Therefore, the braking force of the regenerative torque of the motor MG2 by the hydraulic brake is sufficient. The rate value may not be changed during the replacement, and the replacement of the regenerative torque of the motor MG2 with the braking force by the hydraulic brake may not be performed stepwise.

  In the hybrid vehicles 20 and 20B of the first and second embodiments, the power of the motor MG2 is shifted by the reduction gear 35 and output to the ring gear shaft 32a. However, the hybrid vehicle 120 of the modification of FIG. As illustrated, the power of the motor MG2 is connected to an axle (an axle connected to the wheels 64a and 64b in FIG. 9) different from the axle to which the ring gear shaft 32a is connected (the axle to which the drive wheels 63a and 63b are connected). It is good also as what to do.

  In the hybrid vehicles 20 and 20B of the first and second embodiments, the power of the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30. However, as illustrated in the hybrid vehicle 220 of the modified example of FIG. 10, the inner rotor 232 connected to the crankshaft 26 of the engine 22 and the outer shaft connected to the drive shaft that outputs power to the drive wheels 63a and 63b. The rotor 234 may be provided, and a counter-rotor motor 230 that transmits a part of the power of the engine 22 to the drive shaft and converts the remaining power into electric power may be provided.

  In the embodiment, the hybrid vehicle including the engine 22 and the two motors MG1 and MG2 has been described. However, the present invention includes an electric motor that does not have an engine and can output a braking force to the vehicle, and a hydraulic brake for braking. It may be applied to a vehicle equipped.

Here, 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 engine 22 corresponds to an “internal combustion engine” , the motor MG2 corresponds to an “electric motor” , the brake actuator 92, the brake wheel cylinders 96a to 96d, and the brake ECU 94 correspond to “braking force applying means” , and the vehicle speed. The sensor 88 corresponds to “vehicle speed detection means” and sets the required braking torque Tr * based on the brake pedal position BP and the vehicle speed V. The processing in step S110 of the braking time control routine of FIG. 2 and the braking time control of FIG. The hybrid electronic control unit 70 that executes the process of step S310 of the routine corresponds to “required braking force setting means” . When the vehicle speed V is equal to or higher than the threshold Vref, the torque command Tm2 * of the motor MG2 is set so that the maximum regenerative torque Tset1 is output from the motor MG2, and the brake torque Tb is set so that the required braking torque Tr * is output to the ring gear shaft 32a. * Is set and transmitted to the motor ECU 40 and the brake ECU 94. After the vehicle speed V reaches less than the threshold value Vref, the rate value Trt1 is changed to a larger rate value Trt2 on the way and the hydraulic brake of the regenerative torque of the motor MG2 is performed. The torque command Tm2 * of the motor MG2 is set so that the brake force is replaced by the brake force, and the brake torque Tb * by the hydraulic brake is set so that the required brake torque Tr * is output to the ring gear shaft 32a. It is a process to transmit to the ECU 94 2, the hybrid electronic control unit 70 that executes the processing of steps S120 to S210 of the braking time control routine, the motor ECU 40 that receives the torque command Tm2 * and controls the drive of the motor MG2, and the brake torque Tb * that receives the brake torque Tb *. The brake ECU 94 that controls the driving of the motor 92 corresponds to a “braking control means” , and sets the torque command Tm2 * of the motor MG2 so that the maximum regenerative torque Tset1 is output from the motor MG2 when the vehicle speed V is equal to or higher than the threshold value Vref. The brake torque Tb * is set and transmitted to the motor ECU 40 and the brake ECU 94 so that the required braking torque Tr * is output to the ring gear shaft 32a. After the vehicle speed V reaches less than the threshold value Vref, the rate value Trt is used. Stepwise motor MG2 regeneration torque oil The torque command Tm2 * of the motor MG2 is set so that the braking force is replaced by the brake, and the brake torque Tb * is set by the hydraulic brake so that the required braking torque Tr * is output to the ring gear shaft 32a. The hybrid electronic control unit 70 that executes the processing of steps S320 to S410 of the braking control routine of FIG. 7 that is processing to be transmitted to the brake ECU 94, the motor ECU 40 that receives the torque command Tm2 * and controls the motor MG2, and the brake The brake ECU 94 that receives the torque Tb * and controls the driving of the brake actuator 92 corresponds to the “braking time control means” . Further, the engine 22 corresponds to an “internal combustion engine”, the combination of the power distribution and integration mechanism 30 and the motor MG1 and the anti-rotor motor 230 correspond to “power power input / output means”, and the battery 50 corresponds to “power storage means”. To do. The motor MG1 corresponds to a “generator”, and the power distribution and integration mechanism 30 corresponds to a “3-axis power input / output unit”. Here, the “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor that can input and output power to an input shaft, such as an induction motor. It doesn't matter. The “braking force applying means” is not limited to the hydraulic brake including the brake actuator 92, the brake wheel cylinders 96a to 96d, and the brake ECU 94, and can apply a braking force to the vehicle such as a brake that is not hydraulically driven. It does not matter as long as there is any. The “vehicle speed detection means” is not limited to the vehicle speed sensor 88, and detects vehicle speed, such as that calculated from the rotational speed Nm2 of the motor MG2 or calculated based on a signal from the wheel speed sensor. It does not matter as long as there is any. The “required braking force setting means” is not limited to the one that sets the required braking torque Tr * based on the brake pedal position BP and the vehicle speed V, but the required braking torque Tr based only on the brake pedal position BP. Any device may be used as long as it sets the required braking force required for the vehicle, such as a device for setting * and a device for setting the required braking torque based on the traveling position. The “braking time control means” is not limited to the processing by the braking time control routine of FIG. 2 described above or the processing by the braking time control routine of FIG. 7, and is required for the vehicle when the vehicle speed is equal to or higher than the predetermined vehicle speed. A predetermined braking force is output from the electric motor within the range of the required braking force, and the electric motor and the braking force applying means are controlled so that the required braking force acts on the vehicle. When the vehicle speed becomes less than the predetermined vehicle speed, the electric motor generates a braking force. Controls the electric motor and the braking force application means so that the braking force that is reduced to a value of 0 is output from the electric motor, and the required braking force acts on the vehicle, except for the abnormal noise generating region that generates abnormal noise when outputting Anything can be used. 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. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. 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.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

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

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to a first embodiment of the present invention. It is a flowchart which shows an example of the control routine at the time of a brake performed by the electronic control unit for hybrids 70 of 1st Example. It is explanatory drawing which shows an example of the map for request | requirement braking torque setting. FIG. 4 is an explanatory diagram showing an example of a collinear diagram for dynamically explaining rotational elements of a power distribution and integration mechanism 30. Time of the vehicle speed V when replacing the regenerative torque by the motor MG2 with the braking force by the hydraulic brake, the torque Tm2 of the motor MG2, and the brake torque Tb by the hydraulic brake when converted into the ring gear shaft 32a according to the braking control routine of the first embodiment. It is explanatory drawing which shows a change typically. An explanation schematically showing the time change of the vehicle speed V when replacing the regenerative torque by the motor MG2 in the modified example with the braking force by the hydraulic brake, the torque Tm2 of the motor MG2, and the brake torque Tb by the hydraulic brake when converted to the ring gear shaft 32a. FIG. It is a flowchart which shows an example of the control routine at the time of a braking performed by the electronic control unit for hybrid 70 of 2nd Example. Time of the vehicle speed V when replacing the regenerative torque by the motor MG2 with the braking force by the hydraulic brake, the torque Tm2 of the motor MG2, and the brake torque Tb by the hydraulic brake when converted to the ring gear shaft 32a according to the braking control routine of the second embodiment. It is explanatory drawing which shows a change typically. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example.

20, 20B, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 Carrier, 35 Reduction gear, 37 Gear mechanism, 38 Differential gear, 39a, 39b Drive wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 Battery, 51 Temperature Sensor, 52 Battery electronic control unit (battery ECU), 54 Power line, 63a, 63b Driving wheel, 64a, 64b Wheel, 70 Hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 Ignition Switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 90 brake master cylinder, 92 brake actuator, 94 electronic control unit for brake (Brake ECU), 96a to 96d, brake wheel cylinder, 230 pair rotor motor, 232 inner rotor 234
Outer rotor, MG1, MG2 motor.

Claims (4)

An electric motor capable of outputting braking force to the axle;
Braking force applying means capable of applying braking force to the vehicle;
Vehicle speed detection means for detecting the vehicle speed;
Requested braking force setting means for setting a requested braking force required for the vehicle;
When the detected vehicle speed is equal to or higher than a predetermined vehicle speed, a predetermined braking force that can efficiently regenerate the kinetic energy of the vehicle within the range of the set required braking force is output from the electric motor and the set required braking force is The motor and the braking force applying means are controlled so as to act on the vehicle. When the detected vehicle speed is less than the predetermined vehicle speed, the predetermined braking force is output from the electric motor at a vehicle speed lower than the predetermined vehicle speed. The motor and the braking force applying means are controlled so that a braking force that decreases to a value of 0 is output from the electric motor except for an abnormal noise generation region that generates a sound, and the set required braking force acts on the vehicle. Braking control means,
A vehicle comprising: The vehicle according to claim 1 ,
An internal combustion engine;
Connected to the drive shaft connected to the axle and connected to the output shaft of the internal combustion engine so as to be rotatable independently of the drive shaft, and to the drive shaft and the output shaft with input and output of electric power and power Electric power input / output means for inputting / outputting power;
A power storage means capable of exchanging power with the electric power drive input / output means and the electric motor;
A vehicle comprising: The electric power drive input / output means is connected to three axes of a generator capable of exchanging electric power with the power storage means, the drive shaft, the output shaft, and a rotating shaft of the generator, and any of the three axes The vehicle according to claim 2 , further comprising: a three-axis power input / output unit that inputs / outputs power to the remaining shaft based on power input / output to / from the two shafts. A control method during braking of a vehicle comprising: an electric motor capable of outputting a braking force to an axle; a braking force applying means capable of applying a braking force to the vehicle; and a vehicle speed detecting means for detecting a vehicle speed,
When the detected vehicle speed is equal to or higher than a predetermined vehicle speed, a predetermined braking force that can efficiently regenerate the kinetic energy of the vehicle within the range of the set required braking force is output from the electric motor and the set required braking force is The motor and the braking force applying means are controlled so as to act on the vehicle. When the detected vehicle speed is less than the predetermined vehicle speed, the predetermined braking force is output from the electric motor at a vehicle speed lower than the predetermined vehicle speed. The motor and the braking force applying means are controlled so that a braking force that decreases to a value of 0 is output from the electric motor except for an abnormal noise generation region that generates a sound, and the set required braking force acts on the vehicle. ,
A method for controlling a vehicle.

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