Regenerative braking force control device

Abstract

To provide a regenerative brake force control device which can make a regenerative brake force be a desired brake force without giving troublesome feeling to a driver.SOLUTION: A regenerative brake force control device comprises: a drive motor 2 which can output a regenerative brake force; a paddle shift switch 13 which accepts an input of a correction method of the regenerative brake force; a brake force learning part 32 which stores correction amount of the regenerative brake force determined by the input of the paddle shift switch 13; and a brake force calculation part 31 which corrects, when outputting the regenerative brake force next time, the prescribed brake force on the basis of the correction amount to be the regenerative brake force.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a regenerative braking force control device. [Background technology]

[0002] Patent document 1 describes how, when the accelerator pedal is released, regenerative braking is performed by operating the motor as a generator, and the level of the regenerative braking force can be set at the driver's discretion.

[0003] In the control device described in Patent Document 1, when the accelerator pedal is depressed while regenerative braking is being performed, regenerative braking is stopped, the level of regenerative braking force set by the driver is canceled, and an initial value is set. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-79907 Summary of the Invention [Problem to be solved by the invention]

[0005] In such a regenerative braking force control device, the regenerative braking level set by the driver is reset every time regenerative braking is stopped. Therefore, if the vehicle's specified regenerative braking force does not meet the driver's preferences, the desired braking force must be adjusted every time regenerative braking is performed, which may be annoying for the driver.

[0006] SUMMARY OF THE PRESENT DISCLOSURE OF THE PRESENT DISCLOSURE An object of the present invention is to provide a regenerative braking force control device that can adjust the regenerative braking force to a desired braking force without causing the driver any inconvenience. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a regenerative braking force control device for a vehicle equipped with a rotating electric machine capable of outputting a regenerative braking force, the regenerative braking force control device including: an adjustment unit that receives an input of a method for correcting the regenerative braking force; a braking force learning unit that stores a correction amount of the regenerative braking force determined by the input to the adjustment unit; and a braking force calculation unit that corrects a specified braking force by the correction amount to obtain the regenerative braking force when the regenerative braking force is next output. The adjustment unit uses the received input to change the gear stage of the transmission when the accelerator pedal is depressed, and uses the received input to adjust the regenerative braking force when the accelerator pedal is released or the foot is released from the pedal. This is what we have in mind. Effect of the Invention

[0008] In this way, according to the present invention, the regenerative braking force can be set to a desired braking force without causing the driver any inconvenience. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram of a regenerative braking force control device according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an example of the arrangement of paddle shift switches of the regenerative braking force control device according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a diagram showing an example of a map for determining a prescribed braking force of the regenerative braking force control device according to one embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing an example of correction of a prescribed braking force in the regenerative braking force control device according to one embodiment of the present invention. [Diagram 5] FIG. 5 is a flowchart showing a procedure of a braking force adjustment process of the regenerative braking force control device according to one embodiment of the present invention. [Figure 6] FIG. 6 is a flowchart showing a procedure of a braking force correction process of the regenerative braking force control device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A regenerative braking force control device according to one embodiment of the present invention is a regenerative braking force control device for a vehicle equipped with a rotating electric machine capable of outputting regenerative braking force, and is configured to include an adjustment unit that accepts input of a method for correcting the regenerative braking force, a braking force learning unit that stores a correction amount for the regenerative braking force determined by the input to the adjustment unit, and a braking force calculation unit that corrects a specified braking force with the correction amount to obtain the regenerative braking force when the next regenerative braking force is output.

[0011] As a result, the regenerative braking force control device according to one embodiment of the present invention can set the regenerative braking force to a desired braking force without causing the driver to feel bothered. EXAMPLES

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A regenerative braking force control device according to an embodiment of the present invention will be described in detail below with reference to the drawings.

[0013] In FIG. 1, a vehicle 1 equipped with a regenerative braking force control device according to one embodiment of the present invention includes a drive motor 2 as a rotating electric machine, and an ECU (Electronic Control Unit) 3 as a control unit.

[0014] The vehicle 1 is, for example, a hybrid vehicle that can use the power of both an engine and a drive motor 2 (not shown) to drive the vehicle 1. The vehicle 1 is not limited to a hybrid vehicle, and may be an electric vehicle as long as it is equipped with a drive motor 2 and uses the regenerative braking force of the drive motor 2 to brake the vehicle 1.

[0015] The drive motor 2 is, for example, a synchronous motor equipped with a rotor in which multiple permanent magnets are embedded and a stator around which a stator coil is wound. When a three-phase AC voltage is applied to the stator coil, a rotating magnetic field is generated in the stator of the drive motor 2, which rotates the rotor and generates a driving force.

[0016] Furthermore, the drive motor 2 is driven so that the rotational resistance during power generation is utilized for braking the vehicle 1. This allows the drive motor 2 to have the function of generating power through regeneration.

[0017] The ECU 3 is composed of a computer unit equipped with a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, etc., an input port, and an output port.

[0018] The ROM of this computer unit stores various constants, various maps, and the like, as well as a program for causing the computer unit to function as the ECU 3.

[0019] That is, the CPU executes the programs stored in the ROM using the RAM as a working area, whereby this computer unit functions as the ECU 3 in this embodiment.

[0020] An input port of the ECU 3 is connected to various sensors and switches, such as an accelerator opening sensor 11, a vehicle speed sensor 12, a paddle shift switch 13 as an adjustment unit, a tilt angle sensor 14, a camera 15, a navigation system 16, and the like.

[0021] The accelerator opening sensor 11 detects the opening of an accelerator pedal (not shown) operated by a driver. The vehicle speed sensor 12 detects the speed of the vehicle 1.

[0022] The paddle shift switch 13 is a switch for changing gears in a transmission (not shown) of the vehicle 1. For example, as shown in Fig. 2, the paddle shift switch 13 is disposed on the left and right rear sides of the spoke portion 17a of the steering wheel 17. On the right side of the spoke portion 17a, an upshift switch 13a for changing the gear of the transmission from the current gear to one step higher is provided, and on the left side, a downshift switch 13b for changing the gear of the transmission from the current gear to one step lower is provided.

[0023] In FIG. 1, the tilt angle sensor 14 is configured by, for example, a gyroscope or an acceleration sensor, and outputs sensor information (voltage signal) corresponding to the angle of the traveling direction of the vehicle 1 with respect to the horizontal plane.

[0024] The camera 15 is provided, for example, to capture an image of the area ahead of the vehicle 1. The camera 15 outputs the captured image to the ECU 3. The ECU 3 detects the weather at the current location, the traffic congestion status of the road, and the like from the image captured by the camera 15.

[0025] The navigation system 16 acquires traffic congestion information, road information, and the like from a vehicle information and communication system (VICS) or the like, and outputs the information to the ECU 3.

[0026] On the other hand, various control targets including the drive motor 2 described above are connected to the output port of the ECU 3.

[0027] In this embodiment, the ECU 3 transitions to a one-pedal drive mode in which the vehicle 1 is accelerated and decelerated, and even stopped, by the driver operating a switch, for example, by operating the accelerator pedal only.

[0028] In the one-pedal drive mode, for example, the ECU 3 accelerates when the accelerator pedal is depressed, and decelerates when the accelerator pedal is released or the foot is taken off the accelerator pedal. The ECU 3 utilizes the regenerative braking force of the drive motor 2 during this deceleration.

[0029] For this reason, the ECU 3 includes a braking force calculation unit 31. The braking force calculation unit 31 obtains the regenerative braking force of the drive motor 2, for example, from a map in which the braking force is determined by the accelerator opening and the vehicle speed, as shown in Fig. 3. The regenerative braking force is set to be smaller as the vehicle speed is higher, and smaller as the accelerator opening is larger.

[0030] When the paddle shift switch 13 is operated while the drive motor 2 is outputting a regenerative braking force, the braking force calculation unit 31 adjusts the regenerative braking force.

[0031] At this time, the paddle shift switch 13 becomes a switch for adjusting the regenerative braking force of the vehicle 1, with the upshift switch 13a switching to a regenerative force increase switch 13a that increases the regenerative braking force, and the downshift switch 13b switching to a regenerative force decrease switch 13b that decreases the regenerative braking force.

[0032] The braking force calculation unit 31 adjusts the regenerative braking force to be stronger when the regenerative force increase switch (upshift switch) 13a of the paddle shift switch 13 is operated. The braking force calculation unit 31 adjusts the regenerative braking force to be weaker when the regenerative force decrease switch (downshift switch) 13b of the paddle shift switch 13 is operated.

[0033] The regenerative braking force can be adjusted without using the paddle shift switch 13, and a switch for adjusting the regenerative braking force can be provided. For example, the paddle shift switch 13 is used to change the gear position of the transmission when the accelerator pedal is depressed, and is used to adjust the regenerative braking force when the accelerator pedal is released or the foot is taken off the accelerator pedal. The paddle shift switch 13 may be switched by a switch or the like between being used to change the gear position of the transmission and to adjust the regenerative braking force.

[0034] For example, as shown in Fig. 4, the braking force calculation unit 31 corrects the map as shown by the dotted line when the braking force is to be increased from the specified braking force shown in Fig. 3, and corrects the map as shown by the dashed line when the braking force is to be decreased. The braking force calculation unit 31 may correct the specified braking force by a preset constant amount.

[0035] The braking force calculation unit 31 may be configured to increase the amount of correction of the braking force caused by the operation of the paddle shift switch 13 the first time and decrease it each time the switch is operated. In this way, the braking force desired by the driver can be achieved more quickly.

[0036] The ECU 3 stores the correction amount of the regenerative braking force according to the driver's operation of the paddle shift switch 13, and when outputting the next regenerative braking force, sets the regenerative braking force to the braking force obtained by adding the correction amount to the specified braking force obtained from the map of Fig. 3. For this reason, the ECU 3 is provided with a braking force learning unit 32.

[0037] The braking force learning unit 32 stores the amount of correction to the regenerative braking force in response to the operation of the paddle shift switch 13 by the driver.

[0038] The braking force learning unit 32 may store the correction amount of the regenerative braking force for each driving situation of the vehicle 1.

[0039] The braking force learning unit 32 separately stores a correction amount for the regenerative braking force when the vehicle 1 is traveling downhill with an inclination angle of a predetermined angle or more detected by the inclination angle sensor 14, and adds the correction amount to the specified braking force when the vehicle 1 is traveling downhill with an inclination angle of a predetermined angle or more.

[0040] The braking force learning unit 32 detects the weather at the current location of the vehicle 1, for example, from an image captured by the camera 15 or information obtained from the navigation system 16, separately stores the correction amount for the regenerative braking force when it is raining or the road surface is frozen, and adds the correction amount to the specified braking force when it is raining or the road surface is frozen.

[0041] The braking force learning unit 32 detects the traffic congestion situation on the road on which the vehicle 1 is currently traveling, for example, from an image captured by the camera 15 or information obtained from the navigation system 16, separately stores the correction amount of the regenerative braking force in the case of a specified traffic congestion situation, and adds the correction amount to the specified braking force in the case of the specified traffic congestion situation.

[0042] The braking force learning unit 32 may store the correction amount of the regenerative braking force for each driver. In this way, the braking force can be adjusted to suit the preferences of each driver.

[0043] The braking force adjustment process performed by the regenerative braking force control device according to this embodiment configured as above will be described with reference to Fig. 5. The braking force adjustment process described below is started when the ECU 3 starts operating, and is executed at preset time intervals.

[0044] In step S11, the ECU 3 determines whether or not the accelerator pedal is released.

[0045] If it is determined that the accelerator pedal is released, the ECU 3 executes the process of step S12. If it is determined that the accelerator pedal is not released, the ECU 3 executes the process of step S16.

[0046] In step S12, the ECU 3 determines whether the paddle shift switch 13 has been operated to increase the braking force.

[0047] If it is determined that the paddle shift switch 13 has been operated to increase the braking force, the ECU 3 executes the process of step S13. If it is determined that the paddle shift switch 13 has not been operated to increase the braking force, the ECU 3 executes the process of step S14.

[0048] In step S13, the ECU 3 corrects the prescribed braking force so as to increase the braking force. After executing the process of step S13, the ECU 3 executes the process of step S16.

[0049] In step S14, the ECU 3 determines whether the paddle shift switch 13 has been operated to reduce the braking force.

[0050] If it is determined that the paddle shift switch 13 has been operated to weaken the braking force, the ECU 3 executes the process of step S15. If it is determined that the paddle shift switch 13 has not been operated to weaken the braking force, the ECU 3 executes the process of step S16.

[0051] In step S15, the ECU 3 corrects the specified braking force so as to weaken the braking force. After executing the process of step S14, the ECU 3 executes the process of step S16.

[0052] In step S16, the ECU 3 stores and learns the correction amount. After executing the process of step S16, the ECU 3 ends the braking force adjustment process.

[0053] Next, the braking force correction process performed by the regenerative braking force control device according to this embodiment will be described with reference to Fig. 6. The braking force correction process described below is started when the ECU 3 starts operating, and is executed at preset time intervals.

[0054] In step S21, the ECU 3 calculates a prescribed braking force from the accelerator opening and the vehicle speed. After executing the process of step S21, the ECU 3 executes the process of step S22.

[0055] In step S22, the ECU 3 calculates the braking force by adding the learned braking force correction amount to the specified braking force. After executing the process of step S22, the ECU 3 ends the braking force correction process.

[0056] Thus, in this embodiment, the ECU 3 stores the correction amount of the regenerative braking force resulting from the driver's operation of the paddle shift switch 13, and when outputting the next regenerative braking force, the regenerative braking force is the specified braking force corrected by the correction amount.

[0057] As a result, the regenerative braking force adjusted by the driver is output the next time the regenerative braking force is output, and by repeating this, the driver can obtain the desired regenerative braking force without making any adjustments, thereby reducing the inconvenience to the driver.

[0058] In addition, the ECU 3 stores a correction amount for the regenerative braking force for each specified driving condition of the vehicle 1, and during a specified driving condition, the regenerative braking force is a braking force obtained by correcting a specified braking force with a correction amount corresponding to the specified driving condition.

[0059] This eliminates the need to adjust the regenerative braking force for each driving situation, and allows the driver to obtain a desired regenerative braking force, thereby reducing inconvenience to the driver.

[0060] In addition, the ECU 3 separately stores a correction amount for the regenerative braking force when the vehicle 1 is traveling downhill at a predetermined angle or more, and corrects the specified braking force with that correction amount when the vehicle 1 is traveling downhill at a predetermined angle or more.

[0061] This eliminates the need to adjust the regenerative braking force every time on a downhill road of a predetermined angle or more, where the braking force required is different from that on a flat road, thereby reducing the inconvenience to the driver.

[0062] Furthermore, the ECU 3 separately stores a correction amount for the regenerative braking force when the weather at the current location of the vehicle 1 is raining or when the road surface is frozen, and corrects the specified braking force with that correction amount when the weather at the current location of the vehicle 1 is raining or when the road surface is frozen.

[0063] This eliminates the need to adjust the regenerative braking force every time when it is raining, which requires a different braking force than when it is not raining, or when the road surface is frozen, thereby reducing the inconvenience to the driver.

[0064] Furthermore, the ECU 3 separately stores a correction amount for the regenerative braking force when the traffic congestion situation on the road on which the vehicle 1 is currently traveling is a specified traffic congestion situation, and corrects the specified braking force with that correction amount when the traffic congestion situation on the road on which the vehicle 1 is currently traveling is the specified traffic congestion situation.

[0065] This eliminates the need to adjust the regenerative braking force every time in a specific congestion situation where the braking force required is different from that required when there is no congestion, thereby reducing the inconvenience to the driver.

[0066] The ECU 3 also controls a one-pedal drive function that performs control of acceleration / deceleration and stopping of the vehicle 1 by operating only the accelerator pedal.

[0067] This eliminates the need to shift pedal pressure to obtain braking force, and allows regenerative braking force to be obtained instantly.

[0068] In addition, the paddle shift switch 13 is provided on a spoke portion 17 a of the steering wheel 17 .

[0069] This makes it possible to adjust the regenerative braking force without moving the hands from the steering wheel 17 more than necessary.

[0070] Furthermore, the ECU 3 calculates a prescribed braking force based on the accelerator opening and the vehicle speed. This makes it possible to obtain an appropriate braking force according to the accelerator opening and vehicle speed.

[0071] In this embodiment, an example has been described in which the ECU 3 performs various determinations and calculations based on various sensor information, but the present invention is not limited to this. The vehicle 1 may be provided with a communication unit capable of communicating with an external device such as an external server, and various determinations and calculations may be performed by the external device based on the detection information of the various sensors transmitted from the communication unit. The determination results and calculation results may be received by the communication unit, and various controls may be performed using the received determination results and calculation results.

[0072] Although an embodiment of the invention has been disclosed, it will be apparent to one of ordinary skill in the art that modifications may be made thereto without departing from the spirit and scope of the invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0073] 1 vehicle 2 Drive motor (rotating electric machine) 3 ECU 11 Accelerator opening sensor 12 Vehicle speed sensor 13 Paddle shift switch (adjustment part) 13a Upshift switch (regenerative power increase switch) 13b Downshift switch (regenerative power reduction switch) 14 Inclination sensor 15 Camera 16 Navigation system 17 Steering 17a spoke section 31 Braking force calculation section 32 Braking force learning section

Claims

1. A regenerative braking force control device for a vehicle equipped with a rotating electric machine capable of outputting a regenerative braking force, an adjustment unit that receives an input of a method for correcting the regenerative braking force; a braking force learning unit that stores a correction amount of the regenerative braking force determined by an input to the adjustment unit; a braking force calculation unit that corrects a specified braking force by the correction amount to obtain the regenerative braking force when the regenerative braking force is next output; The adjustment unit uses the received input to change the gear ratio of a transmission when an accelerator pedal is depressed, and uses the received input to adjust the regenerative braking force when the accelerator pedal is released or the foot is released.

2. 2. The regenerative braking force control device according to claim 1, wherein the braking force learning unit stores the correction amount for each specified driving condition of the vehicle, and during the specified driving condition, the regenerative braking force is a braking force obtained by correcting the specified braking force with the correction amount corresponding to the specified driving condition.

3. 3. The regenerative braking force control device according to claim 2, wherein the braking force learning unit stores the correction amount when the vehicle is traveling on a downhill slope of a predetermined angle or more as the predetermined driving condition.

4. The regenerative braking force control device according to claim 2 , wherein the braking force learning unit stores the correction amount according to weather at a current location of the vehicle as the predetermined driving condition.

5. 3. The regenerative braking force control device according to claim 2, wherein the braking force learning unit stores the correction amount when a traffic congestion situation on a road on which the vehicle is currently traveling is a predetermined traffic congestion situation as the predetermined driving situation.

6. The regenerative braking force control device according to any one of claims 1 to 5, wherein the vehicle has a one-pedal drive function that enables acceleration and deceleration to be controlled with one pedal.

7. The regenerative braking force control device according to any one of claims 1 to 6, wherein the adjustment unit is provided on a steering wheel of the vehicle.

8. 8. The regenerative braking force control device according to claim 1, wherein the braking force calculation unit calculates the specified braking force based on an accelerator opening and a vehicle speed.

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