JP4581406B2 - Regenerative braking control device - Google Patents

Description

  The present invention relates to a regenerative braking control device for an automobile that performs braking using regenerative braking of a motor, and more particularly to a regenerative braking control device that can prevent noise.

  Patent Document 1 discloses a regenerative braking control device for an electric vehicle. The electric vehicle includes a driving induction motor and a speed reducer that decelerates the rotation of the driving induction motor and outputs the reduced speed to driving wheels. The regenerative braking control means includes rotation fluctuation detection means, calculation comparison means, and braking torque control means.

  The rotation fluctuation detecting means detects a rotation fluctuation in the output shaft of the speed reducer. The operation comparison means compares the rotation fluctuation detected by the rotation fluctuation detection means with a reference value. The braking torque control means increases the regenerative braking torque when the rotational fluctuation becomes larger than the reference value.

In this way, the regenerative braking control means detects the rotational fluctuation in the output shaft of the speed reducer, and increases the braking torque when the detected rotational fluctuation becomes larger than the reference value. Thereby, the regenerative braking control means prevents vibration and noise due to rattling of the gear of the speed reducer.
JP-A-3-261306

  However, since the method disclosed in Patent Document 1 is to prevent noise caused by rattling of the gear of the speed reducer, it is difficult to suppress the noise of the motor that drives the drive wheels during deceleration regeneration.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide a regenerative braking control device capable of suppressing noise of a driving motor during deceleration regeneration.

  A regenerative braking control device according to the present invention is a regenerative braking control device mounted on an automobile including drive wheels and a drive motor for driving the drive wheels, and includes a transmission and control means. The transmission changes the reduction ratio between the drive wheel and the drive motor. The control means controls the transmission so that the reduction ratio becomes high during deceleration regeneration of the drive motor.

  Preferably, the control means controls the transmission so that the gear in the transmission is switched from a high gear having a relatively small reduction ratio to a low gear having a relatively large reduction ratio during deceleration regeneration.

  Preferably, the control means controls the transmission so that the reduction ratio is increased when the speed of the automobile is reduced to a predetermined speed at which the noise of the driving motor becomes a reference value.

  Preferably, the regenerative braking control device further includes a vehicle speed sensor that detects a speed of the automobile. And a control means controls a transmission so that a reduction ratio may become high, when the speed from a vehicle speed sensor falls to predetermined speed.

  Preferably, the control means holds a map indicating the relationship between the noise of the driving motor and the speed of the automobile, and when detecting that the speed from the vehicle speed sensor has decreased to a predetermined speed with reference to the map, the control means The transmission is controlled so that the ratio becomes high.

  Further, according to the present invention, the regenerative braking control device is a regenerative braking control device mounted on an automobile including drive wheels and a drive motor for driving the drive wheels, and includes a drive circuit and control means. . The drive circuit drives a drive motor. The control means performs regeneration amount suppression control for controlling the drive circuit so as to suppress the regeneration amount in the drive motor during a predetermined period when the noise of the drive motor is equal to or higher than a reference value during deceleration regeneration of the drive motor.

  Preferably, the regenerative braking control device further includes a hydraulic brake that brakes the drive wheels. Then, the control means further performs braking force reinforcement control for controlling the hydraulic brake so as to compensate for a decrease in the braking force of the driving wheel due to the suppression of the regeneration amount for a predetermined period.

  Preferably, when the rotation speed of the drive motor is reduced to a predetermined rotation speed at which the noise of the drive motor becomes a reference value, the control means performs regeneration amount suppression control and braking force reinforcement control.

  Preferably, the regenerative braking control means further includes a rotation speed sensor that detects a rotation speed of the drive motor. And a control means will perform regeneration amount suppression control and braking force reinforcement control, if the rotational speed from a rotational speed sensor falls to predetermined rotational speed.

  Preferably, the control means holds a map indicating a relationship between the regenerative braking force by the drive motor and the brake braking force by the hydraulic brake and the rotational speed of the drive motor, and the regeneration amount suppression control and the braking force reinforcement are performed according to the map. Take control.

  Further, according to the present invention, the regenerative braking control device is a regenerative braking control device mounted on an automobile including a drive wheel and a drive motor for driving the drive wheel, the transmission, the drive circuit, 1 and 2nd control means. The transmission changes the reduction ratio between the drive wheel and the drive motor. The drive circuit drives a drive motor. The first control means performs a reduction ratio control for controlling the transmission so that the reduction ratio becomes high during the deceleration regeneration of the drive motor. The second control means is a regeneration amount suppression control for controlling the drive circuit so as to suppress the regeneration amount in the drive motor during a predetermined period when the noise of the drive motor is greater than or equal to a reference value during the deceleration regeneration of the drive motor. To do.

  Preferably, the regenerative braking control means further includes a hydraulic brake that brakes the drive wheels. Then, the second control means further performs a braking force reinforcement control for controlling the hydraulic brake so as to compensate for a decrease in the braking force of the driving wheel due to the suppression of the regeneration amount for a predetermined period.

  In the regenerative braking control device according to the present invention, when the automobile is decelerated, the reduction ratio in the transmission is controlled to be high. And the period when the noise of a drive motor becomes more than a reference value is shortened.

  Therefore, according to this invention, the noise of the drive motor can be suppressed.

  In the regenerative braking control device according to the present invention, the regenerative amount of the drive motor is suppressed when the automobile is decelerated.

  Therefore, according to the present invention, noise due to regeneration of the drive motor can be suppressed.

  Furthermore, in the regenerative braking control device according to the present invention, when the automobile is decelerated, the reduction ratio of the transmission is controlled to be high, and the regenerative amount of the drive motor is suppressed.

  Therefore, according to this invention, the noise of the drive motor can be further suppressed.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
1 is a schematic block diagram of a drive system including a regenerative braking control device according to Embodiment 1 of the present invention. Referring to FIG. 1, drive system 100 includes drive wheel 10, power transmission gear 20, power take-off gear 30, planetary gear 40, transmission 50, engine 60, inverter 70, and hydraulic brake 80. Vehicle speed sensor 90, hybrid ECU (Electrical Control Unit) 110, engine ECU 120, hydraulic controller 130, brake ECU 140, and motor generators MG1 and MG2. The drive system 100 is mounted on a hybrid vehicle.

  The drive wheel 10 includes a shaft 11 and a tire 12. The tire 12 is attached to the shaft 11 and is rotated by the power transmitted to the shaft 11 via the power transmission gear 20. The power transmission gear 20 is provided on the shaft 11 of the drive wheel 10. The power take-off gear 30 is provided on the ring gear shaft 41 of the planetary gear 40 between the planetary gear 40 and the transmission 50. The power takeout gear 30 is connected to the power transmission gear 20.

  Motor generator MG2 is coupled to ring gear shaft 41 of planetary gear 40. Transmission 50 is provided on ring gear shaft 41 between power take-off gear 30 and motor generator MG2.

  The engine 60 is connected to the carrier shaft 42 of the planetary gear 40. Motor generator MG <b> 1 is connected to sun gear shaft 43 of planetary gear 40. Thereby, motor generator MG1 and engine 60 are connected to each other via planetary gear 40. The hydraulic brake 80 is provided on the shaft 11 of the drive wheel 10.

  The drive wheel 10 is rotated by the power transmitted to the power transmission gear 20. The power transmission gear 20 transmits the power received from the power take-out gear 30 to the drive wheels 10.

  The power take-off gear 30 takes out the power output from the engine 60 to the ring gear shaft 41 via the planetary gear 40 and / or the power output from the motor generator MG2 to the ring gear shaft 41 via the transmission 50, and The extracted power is transmitted to the power transmission gear 20.

  Planetary gear 40 transmits the power output from motor generator MG1 to sun gear shaft 43 to engine 60 via carrier shaft 42, and divides the power output from engine 60 to carrier shaft 42 to split ring gear shaft 41 and Output to the sun gear shaft 43.

  Transmission 50 reduces the rotational speed of motor generator MG2 to increase the output torque output from motor generator MG2, and outputs the increased output torque to ring gear shaft 41. When transmission 50 receives shift signal CHS from hybrid ECU 110, transmission 50 switches from a high gear having a relatively small reduction ratio to a low gear having a relatively large reduction ratio, and reduces the rotational speed of motor generator MG2 to generate a large output torque. Is output to the ring gear shaft 41. That is, the transmission 50 increases the reduction ratio and reduces the rotational speed in accordance with the shift signal CHS.

  Engine 60 is activated by power received from motor generator MG1 via planetary gear 40, and outputs predetermined power in accordance with control from engine ECU 120.

  Motor generator MG1 is driven by inverter 70 and outputs a predetermined torque to sun gear shaft 43 of planetary gear 40. In addition, motor generator MG1 generates an AC voltage using the power of engine 60 output to sun gear shaft 43 of planetary gear 40, and supplies the generated AC voltage to inverter 70 via three-phase power line 71. Further, motor generator MG1 includes rotation speed sensor 13 and outputs rotation speed signal RSD1 detected by rotation speed sensor 13 to hybrid ECU 110.

  Motor generator MG <b> 2 is driven by inverter 70 and outputs a predetermined torque to transmission 50. Motor generator MG <b> 2 generates an AC voltage using the power of drive wheel 10, and supplies the generated AC voltage to inverter 70 via three-phase power line 72. Further, motor generator MG2 includes a rotation speed sensor 14 and outputs rotation speed signal RSD2 detected by rotation speed sensor 14 to hybrid ECU 110.

  Inverter 70 is connected to motor generator MG1 by a three-phase power line 71 and is connected to motor generator MG2 by a three-phase power line 72. Inverter 70 converts a DC voltage from a battery (not shown) into an AC voltage in accordance with drive signal DRV from hybrid ECU 110, and supplies the converted AC voltage to motor generator MG1 via three-phase power line 71. Then, motor generator MG1 is driven in the power running mode or the regeneration mode.

  Inverter 70 converts a DC voltage from a battery (not shown) into an AC voltage in accordance with drive signal DRV from hybrid ECU 110, and supplies the converted AC voltage to motor generator MG2 via three-phase power line 72. Then, motor generator MG2 is driven in the power running mode or the regeneration mode.

  The hydraulic brake 80 receives the brake hydraulic pressure from the hydraulic controller 130 and applies a braking force to the drive wheels 10 according to the received brake hydraulic pressure. As a result, the hybrid vehicle on which the drive system 100 is mounted decelerates.

  The vehicle speed sensor 90 detects the rotational speed of the drive wheel 10, converts the detected rotational speed into a vehicle speed SPD, and outputs the vehicle speed SPD to the hybrid ECU 110. The hybrid ECU 110 includes an accelerator pedal position (accelerator pedal depression amount) AP from an accelerator pedal position sensor (not shown), a brake pedal position (brake pedal depression amount) BP from a brake pedal position sensor (not shown), Shift position SP from a shift position sensor (not shown), motor currents MCRT1 and 2 from current sensors (not shown) attached to motor generators MG1 and MG2, and rotational speed signals from rotational speed sensors 13 and 14 Receive RSD1,2. Based on these signals, hybrid ECU 110 generates a drive signal DRV for driving motor generators MG1 and MG2 by controlling the current flowing through the three-phase coils of motor generators MG1 and MG2. Drive signal DRV is output to inverter 70.

  Further, when hybrid ECU 110 detects deceleration of the hybrid vehicle based on brake pedal position BP, hybrid ECU 110 generates a shift signal CHS for controlling transmission 50 so as to increase the reduction ratio in transmission 50 and outputs it to transmission 50. To do.

  Further, the hybrid ECU 110 calculates a required braking force based on the brake pedal position BP. Hybrid ECU 110 then regenerates motor generator MG2 based on the calculated required braking force, the SOC (State Of Charge) of a battery (not shown), and the rotational speed of motor generator MG2 indicated by rotational speed signal RSD2. The amount is calculated, and the distribution of the calculated regenerative amount (= braking force by regeneration) to the required braking force is further calculated.

  Then, hybrid ECU 110 generates regeneration amount signal REGV indicating the calculated distribution and outputs it to brake ECU 140. Hybrid ECU 110 receives regeneration permission amount signal REGA from brake ECU 140, calculates a regeneration amount that motor generator MG2 can regenerate based on the received regeneration permission amount signal REGA, and uses the calculated regeneration amount as motor generator MG2. A drive signal DRV (regeneration instruction signal) for driving the inverter 70 is generated so as to be regenerated and output to the inverter 70.

  Further, hybrid ECU 110 instructs engine ECU 120 on the power to be output by engine 60.

  Engine ECU 120 drives engine 60 such that engine 60 outputs the power instructed from hybrid ECU 110. More specifically, engine ECU 120 drives engine 60 to output a predetermined power by controlling the fuel injection amount, the rotational speed, and the like.

  The hydraulic controller 130 receives the brake control signal BCTL from the brake ECU 140, calculates the brake hydraulic pressure for applying the braking force indicated by the received brake control signal BCTL to the drive wheels 10, and uses the calculated brake hydraulic pressure as the hydraulic brake 80. Output to.

  The brake ECU 140 receives the regeneration amount signal REGV from the hybrid ECU 110, and receives the rotational speed signal RSD2 from the rotational speed sensor 14 built in the motor generator MG2. Then, brake ECU 140 determines the distribution of braking force by hydraulic brake 80 and the distribution of braking force by regeneration of motor generator MG2 in accordance with the rotational speed of motor generator MG2 indicated by the received rotational speed signal RSD2.

  FIG. 2 is a relationship diagram between the distribution of braking force and the rotational speed of the motor. In FIG. 2, the horizontal axis represents the rotational speed of the motor, and the vertical axis represents the distribution of braking force. Referring to FIG. 2, the distribution of braking force is performed according to rotation speed RSD2 of motor generator MG2 according to straight line LN1. Region RE1 shows the distribution of braking force by hydraulic brake 80, and region RE2 shows the distribution of braking force by regeneration of motor generator MG2.

  Then, the brake ECU 140 distributes the braking force by the hydraulic break 80 and the braking force by regeneration of the motor generator MG2 in accordance with the rotational speed of the motor generator MG2 indicated by the rotational speed signal RSD2 from the rotational speed sensor 14. Determine according to straight line LN1.

  Then, the brake ECU 140 adjusts the distribution of the regeneration amount indicated by the regeneration amount signal REGV based on the determined braking force distribution by regeneration, generates a regeneration permission amount signal REGA indicating the distribution of the adjusted regeneration amount, and hybrids. Output to ECU 110. Further, the brake ECU 140 calculates a braking force that the hydraulic brake 80 applies to the drive wheels 10 according to the determined distribution of the braking force by the hydraulic brake 80, generates a brake control signal BCTL indicating the calculated braking force, and generates the hydraulic controller 130. Output to.

  In the first embodiment, the transmission 50, the vehicle speed sensor 90, and the hybrid ECU 110 that controls the transmission 50 constitute the “regenerative braking control device 200” according to the first embodiment.

  FIG. 3 is a relationship diagram between motor noise and motor rotation speed. In FIG. 3, the horizontal axis represents the motor rotation speed, and the vertical axis represents the motor noise. The motor noise is generated when the natural frequency of the motor housing matches the regenerative sound frequency of the motor. Referring to FIG. 3, there is a relationship indicated by curve k1 between motor noise and motor rotation speed. That is, the motor noise becomes the largest in a predetermined range of the motor rotation speed.

  FIG. 4 is a relationship diagram between motor noise and vehicle speed. In FIG. 4, the horizontal axis represents vehicle speed, and the vertical axis represents motor noise. Referring to FIG. 4, there is a relationship indicated by curves k2 and k3 between the motor noise and the vehicle speed. Curve k2 shows the relationship between motor noise and vehicle speed when the reduction ratio set in transmission 50 is small (that is, when high gear is selected), and curve k3 is set in transmission 50. The relationship between the motor noise and the vehicle speed when the reduction ratio is large (that is, when the low gear is selected) is shown.

  In both cases where the reduction ratio is large and the reduction ratio is small, the noise of the motor becomes equal to or higher than the reference value STD within a predetermined range of the vehicle speed. Therefore, the relationship between motor noise and vehicle speed is similar to the relationship between motor noise and motor rotation speed. This is because the rotational speed of the motor has a linear relationship with the vehicle speed.

  When the reduction ratio is small, the range of the vehicle speed at which the motor noise is equal to or higher than the reference value STD is the range of v1 to v2, and the interval of the vehicle speed is ITV1 (see curve k2). In addition, when the reduction ratio is large, the range of the vehicle speed where the motor noise is equal to or higher than the reference value STD is the range of v3 to v4, and the interval of the vehicle speed is ITV2 (see curve k3). The interval ITV2 is narrower than ITV1. That is, the time during which the motor noise is equal to or higher than the reference value STD is shortened.

  Therefore, in the first embodiment, when the hybrid vehicle is decelerated, hybrid ECU 110 generates shift signal CHS and outputs it to transmission 50, and the reduction ratio in transmission 50 is small when motor generator MG2 decelerates and regenerates. The transmission 50 is controlled to switch from the state (high gear) to the large state (low gear).

  As a result, the time during which the motor noise is equal to or higher than the reference value STD can be shortened. That is, motor noise can be suppressed. Further, the resonance peak between the natural vibration of the motor housing and the motor noise can be reduced.

  When the hybrid ECU 110 detects the deceleration of the hybrid vehicle based on the brake pedal position BP, the hybrid ECU 110 may generate a shift signal CHS at any timing and output it to the transmission 50. After detecting the deceleration of the hybrid vehicle, the vehicle speed sensor 90 The shift signal CHS may be generated and output to the transmission 50 at a timing when the vehicle speed from the vehicle speed decreases to a predetermined vehicle speed v1. In this case, the hybrid ECU 110 holds a map (curve k2) indicating the relationship between the motor noise and the vehicle speed. With reference to the map, the hybrid ECU 110 indicates that the vehicle speed from the vehicle speed sensor 90 has decreased to the predetermined vehicle speed v1. When detected, a shift signal CHS is generated and output to the transmission 50.

  Thereby, the noise of the motor changes according to the curve k2 until the vehicle speed decreases to the vehicle speed v1, and changes according to the curve k2 when the vehicle speed is equal to or less than v1. As a result, the vehicle speed interval at which the motor noise becomes equal to or higher than the reference value STD can be narrowed to the interval ITV2.

  Further, after detecting the deceleration of the hybrid vehicle, the hybrid ECU 110 generates a shift signal CHS and outputs it to the transmission 50 when the vehicle speed from the vehicle speed sensor 90 decreases to the vehicle speed v1, and the vehicle speed from the vehicle speed sensor 90 becomes the vehicle speed v5. When the speed decreases, the shift signal CHSU may be generated and output to the transmission 50. This shift signal CHSU is a signal for controlling the transmission 50 so that the gear in the transmission 50 is switched from a low gear having a relatively large reduction ratio to a high gear having a relatively small reduction ratio.

  Thus, the motor noise changes according to the curve k2 until the vehicle speed decreases to the vehicle speed v1, changes according to the curve k3 when the vehicle speed is in the range of v1 to v5, and changes according to the curve k2 when the vehicle speed is v5 or less. . As a result, the vehicle speed interval at which the motor noise becomes equal to or higher than the reference value STD can be reduced to the interval ITV3 (<ITV2).

  As described above, the first embodiment is characterized in that the reduction ratio is switched from a small state (high gear) to a large state (low gear) by regenerative braking control device 200 when motor generator MG2 is decelerated and regenerated. That is, the gear is switched so that the reduction ratio becomes high.

  Referring again to FIG. 1, in drive system 100, engine 60 is activated by the output torque of motor generator MG <b> 1 received via planetary gear 40 in accordance with control from engine ECU 120. The engine 60 transmits predetermined power to the drive wheels 10 via the planetary gear 40, the power take-out gear 30 and the power transmission gear 20. As a result, the hybrid vehicle equipped with the drive system 100 is started.

  Thereafter, when acceleration of the hybrid vehicle is detected by accelerator pedal position AP, hybrid ECU 110 controls inverter 70 to drive motor generator MG2, and inverter 70 outputs motor generator MG2 to output a predetermined torque. Drive. Motor generator MG2 outputs a predetermined torque, and transmission 50 decelerates the rotational speed of motor generator MG2 and transmits the predetermined torque to drive wheels 10 via power take-off gear 30 and power transmission gear 20. To do. Thus, drive wheel 10 is driven by the power from engine 60 and the power from motor generator MG2, and the hybrid vehicle is accelerated.

  When deceleration of the hybrid vehicle is detected by the brake pedal position BP, the hybrid ECU 110 generates a shift signal CHS and outputs it to the transmission 50. The transmission 50 switches from a high gear having a relatively small reduction ratio to a low gear having a relatively large reduction ratio in accordance with a shift signal CHS from the hybrid ECU 110. Then, drive system 100 brakes drive wheel 10 by regeneration of motor generator MG2 with the reduction ratio increased. As a result, in a hybrid vehicle equipped with drive system 100, motor noise can be suppressed when motor generator MG2 is decelerated and regenerated.

  Hybrid ECU 110 constitutes “control means” for controlling transmission 50 such that the reduction ratio in transmission 50 is increased.

  Motor generator MG2 constitutes a “drive motor” that drives drive wheels 10.

  Furthermore, inverter 70 constitutes a “drive circuit” that drives a drive motor (motor generator MG2).

[Embodiment 2]
FIG. 5 is a schematic block diagram of a drive system including a regenerative braking control device according to the second embodiment. Referring to FIG. 5, in drive system 100A according to the second embodiment, transmission 50 of drive system 100 shown in FIG. 1 is replaced with transmission 50A, hybrid ECU 110 is replaced with hybrid ECU 110A, and brake ECU 140 is replaced with brake ECU 140A. The rest is the same as the drive system 100.

  The transmission 50A receives the shift signal CHSC from the hybrid ECU 110A, and continuously switches the reduction ratio from a small state (high gear) to a large state (low gear) by the received shift signal CHSC. That is, the transmission 50A does not change the reduction ratio from a small state (high gear) to a large state (low gear) at a stretch by the shift signal CHSC, but gradually from a small state (high gear) to a large state (low gear). Switch continuously.

  When hybrid ECU 110A detects deceleration of the hybrid vehicle based on brake pedal position BP, hybrid ECU 110A generates shift signal CHSC and outputs it to transmission 50A. Hybrid ECU 110A calculates a regeneration amount that motor generator MG2 can regenerate based on regeneration permission amount signal REGA from brake ECU 140A, and instructs regeneration to instruct inverter 70 so that motor generator MG2 regenerates the calculated regeneration amount. A signal REG is generated and output to the inverter 70. The hybrid ECU 110A performs the same functions as the hybrid ECU 110.

  The brake ECU 140A determines the distribution of the regeneration amount by the motor generator MG2 so that the noise by the motor generator MG2 is reduced during the deceleration regeneration of the motor generator MG2, and generates a regeneration permission amount signal REGA2 indicating the distribution of the determined regeneration amount. And output to the hybrid ECU 110A.

  The brake ECU 140A performs the same functions as the brake ECU 140.

  In the second embodiment, inverter 70, hydraulic brake 80, hybrid ECU 110A, hydraulic controller 130, and brake ECU 140A constitute “regenerative braking control device 200A” according to the second embodiment.

  FIG. 6 is a relationship diagram between the motor regenerative sound and the distribution of the braking force and the rotational speed of the motor. In FIG. 6, the horizontal axis represents the rotational speed of the motor, and the vertical axis represents the distribution of the motor regenerative sound and the braking force.

  Referring to FIG. 6, curve k4 represents the motor regenerative sound when the distribution of braking force by hydraulic brake 80 and the distribution of braking force by regeneration of motor generator MG2 are determined according to straight line LN1 as in the first embodiment. The relationship with the rotational speed of a motor is shown. Curve k5 shows the relationship between the motor regenerative sound and the rotation speed of the motor when the distribution of braking force by hydraulic brake 80 and the distribution of braking force by regeneration of motor generator MG2 are determined according to curve k6. Furthermore, region RE3 shows the distribution of braking force by hydraulic brake 80, and region RE4 shows the distribution of braking force by regeneration of motor generator MG2.

  When the rotational speed of the motor is in the range of MRS1 to MRS2, the regenerative sound of the motor suddenly increases. In this rotational speed range, the brake ECU 140A follows the curve k6 to distribute the braking force by the hydraulic brake 80 and the motor. The distribution of braking force by regeneration of the generator MG2 is determined. In other words, in the range where the motor regenerative sound is high (the rotational speed is in the range of MRS1 to MRS2), brake ECU 140A reduces the distribution of the regenerative amount by motor generator MG2, and reduces the braking force accompanying the decrease in the regenerative amount. To compensate, the distribution of the braking force by the hydraulic brake 80 is increased.

  As a result, the regenerative sound of the motor can be greatly reduced when the rotational speed is in the range of MRS1 to MRS2 as indicated by the curve k5.

  The brake ECU 140A holds a map (curve k6) indicating the relationship between the distribution of braking force and the rotational speed of the motor, and according to the rotational speed indicated by the rotational speed signal RSD2 from the rotational speed sensor 14. With reference to the map, the distribution of braking force by hydraulic brake 80 and the distribution of braking force by regeneration of motor generator MG2 are determined.

  The operation of brake ECU 140A after determining the distribution of braking force by hydraulic brake 80 and the distribution of braking force by regeneration of motor generator MG2 is the same as the operation of brake ECU 140 described above.

  Thus, the second embodiment is characterized in that the regenerative sound (= noise) of the motor is suppressed by reducing the regenerative amount of the motor generator MG2. When reducing the regeneration amount of motor generator MG2, preferably, the distribution of braking force by hydraulic brake 80 is increased so as to compensate for the decrease in braking force accompanying the decrease in regeneration amount. Thereby, the noise of a motor can be suppressed, ensuring fuel consumption by regenerative braking.

  When the rotational speed is in the range of MRS1 to MRS2, the distribution of the regeneration amount by motor generator MG2 is decreased, and the distribution of the braking force by hydraulic brake 80 is increased so as to compensate for the decrease in braking force accompanying the decrease in the regeneration amount. In this way, the hydraulic pressure is reduced so as to reduce the distribution of the regeneration amount by the motor generator MG2 during a predetermined period (the period during which the rotational speed becomes MRS1 to MRS2) and compensate for the decrease in the braking force accompanying the decrease in the regeneration amount. This corresponds to controlling so that the distribution of the braking force by the brake 80 is increased.

  Hybrid ECU 110A and brake ECU 140A constitute “control means” that performs regeneration amount suppression control for controlling the drive circuit (inverter 70) so as to suppress the regeneration amount in drive motor (motor generator MG2).

  Others are the same as in the first embodiment.

[Embodiment 3]
FIG. 7 is a schematic block diagram of a drive system including a regenerative braking control device according to the third embodiment. Referring to FIG. 7, drive system 100B according to the third embodiment is obtained by replacing hybrid ECU 110 of drive system 100 shown in FIG. 1 with hybrid ECU 110B, and replacing brake ECU 140 with brake ECU 140A. The same as 100.

  The hybrid ECU 110B has both the function of the hybrid ECU 110 and the function of the hybrid ECU 110A. The brake ECU 140A is as described in the second embodiment.

  Therefore, in drive system 100B, at the time of deceleration regeneration of motor generator MG2, the reduction ratio of transmission 50 is switched from a high gear having a relatively small reduction ratio to a low gear having a relatively large reduction ratio as described in the first embodiment. Thus, noise due to regeneration of motor generator MG2 is suppressed, and noise due to regeneration of motor generator MG2 is suppressed by reducing the amount of regeneration of motor generator MG2 as described in the second embodiment.

  Therefore, in the drive system 100B, the noise of the motor can be further suppressed as compared with the drive systems 100 and 100A.

  In the third embodiment, the transmission 50, the inverter 70, the hydraulic brake 80, the vehicle speed sensor 90, the hybrid ECU 110B, and the brake ECU 140A constitute the “regenerative braking control device 200B” according to the third embodiment.

  Hybrid ECU 110 </ b> B constitutes “first control means” for controlling transmission 50 so that the reduction ratio in transmission 50 is increased.

  Further, hybrid ECU 110B and brake ECU 140A constitute “second control means” that performs regeneration amount suppression control for controlling the drive circuit (inverter 70) so as to suppress the regeneration amount in drive motor (motor generator MG2). .

  The rest is the same as in the first and second embodiments.

  In Embodiments 1 to 3 described above, drive systems 100, 100A, 100B and regenerative braking control devices 200, 200A, 200B have been described as being mounted on a hybrid vehicle. However, in the present invention, Not limited to this, the drive systems 100, 100A, 100B and the regenerative braking control devices 200, 200A, 200B may be mounted on an electric vehicle. In this case, motor generators MG1 and MG2 are coupled to drive wheels of the electric vehicle.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a regenerative braking control device capable of suppressing noise of a driving motor during deceleration regeneration.

It is a schematic block diagram of a drive system provided with the regenerative braking control apparatus by Embodiment 1 of this invention. FIG. 6 is a relationship diagram between the distribution of braking force and the rotation speed of a motor. FIG. 6 is a relationship diagram between motor noise and motor rotation speed. FIG. 5 is a relationship diagram between motor noise and vehicle speed. 6 is a schematic block diagram of a drive system including a regenerative braking control device according to Embodiment 2. FIG. FIG. 6 is a relationship diagram between motor regenerative sound and braking force distribution and motor rotation speed. FIG. 10 is a schematic block diagram of a drive system including a regenerative braking control device according to Embodiment 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Drive wheel, 11 Shaft, 12 Tire, 13, 14 Rotational speed sensor, 20 Power transmission gear, 30 Power take-off gear, 40 Planetary gear, 41 Ring gear shaft, 42 Carrier shaft, 43 Sun gear shaft, 50, 50A Transmission, 60 engine, 70 inverter, 71, 72 three-phase power line, 80 hydraulic brake, 90 vehicle speed sensor, 100, 100A, 100B drive system, 110, 110A, 110B hybrid ECU, 120 engine ECU, 130 hydraulic controller, 140, 140A brake ECU , 200, 200A, 200B Regenerative braking control device.

Claims (6)

A regenerative braking control device mounted on an automobile comprising a drive wheel and a drive motor for driving the drive wheel,
A transmission that changes a reduction ratio between the drive wheel and the drive motor;
A first control means for controlling the transmission so that the reduction ratio is increased when the speed of the automobile is reduced to a predetermined speed at which the noise of the drive motor becomes a reference value during deceleration regeneration of the drive motor. And a regenerative braking control device. The first control means controls the transmission so that a gear in the transmission is switched from a high gear having a relatively small reduction ratio to a low gear having a relatively large reduction ratio during the deceleration regeneration. The regenerative braking control device according to Item 1. A vehicle speed sensor for detecting the speed of the automobile;
2. The regenerative braking control device according to claim 1 , wherein the first control unit controls the transmission such that the reduction ratio is increased when a speed from the vehicle speed sensor is decreased to the predetermined speed. The first control means holds a map indicating a relationship between the noise of the driving motor and the speed of the automobile, and the speed from the vehicle speed sensor has decreased to the predetermined speed with reference to the map. The regenerative braking control device according to claim 3 , wherein the transmission is controlled so that the reduction ratio becomes high when this is detected. And a drive circuit for driving the previous Symbol drive motor,
Predetermined period of time the noise is equal to or greater than the reference value of the drive motor before SL during deceleration regeneration, the second performing regeneration amount suppression control for controlling the drive circuit so as to suppress the regeneration amount of the driving motor The regenerative braking control device according to claim 1 , further comprising control means. A hydraulic brake for braking the drive wheel;
Said second control means, the predetermined time period, further the braking force reinforcement control for controlling the hydraulic braking so as to compensate for the reduction in the braking force of the drive wheels by said regeneration amount of suppression, according to claim 5 Regenerative braking control device.

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