Control device

Abstract

To prevent a vehicle from running backward even when a state of a road surface varies, while suppressing variation in hydraulic brake feeling, in performing stop control in a vehicle equipped with a rotary electric machine and a hydraulic brake.SOLUTION: A control device, which controls a vehicular driving device, executes: first vehicle-stop pre-control in which braking operation is performed using a hydraulic brake in addition to regenerative braking performed by a rotary electric machine and rotation speed control of the rotary electric machine is performed, in a state where vehicle speed is equal to or below first reference speed, when a running vehicle stops; and second vehicle-stop pre-control in which rotation speed control of the rotary electric machine is performed, in a state where the vehicle speed is equal to or below second reference speed less than the first reference speed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] For example, vehicles equipped with rotating electric machines as a driving force source for wheels, such as electric vehicles and hybrid vehicles, are in use. An example of a control device for controlling such a vehicle drive device is disclosed in Japanese Patent Application Laid-Open No. 2022-99702 (Patent Document 1).

[0003] The control device (control device 10) of Patent Document 1, when a vehicle (vehicle 100) stops from a running state, outputs a braking / driving torque to a rotating electric machine (rotating electric machine 141) to cause the rotating electric machine to regenerate, thereby improving electricity efficiency. At this time, the control device controls the rotating electric machine to stop by changing the torque of the rotating electric machine along a predetermined stopping waveform just before the vehicle stops. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-99702 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the stopping control in Patent Document 1 merely controls the torque of the rotating electric machine using a feedforward method. As a result, there is a possibility that the vehicle may move in reverse if, for example, the gradient of the road surface or surface friction changes. Also, since some drivers feel uncomfortable stopping the vehicle using only the torque of the rotating electric machine, it is possible to use hydraulic brakes in combination, but variations in hydraulic pressure may result in variations in the hydraulic brake feeling.

[0006] Therefore, when performing stopping control on a vehicle equipped with a rotating electric machine and hydraulic brakes, it is desirable to minimize variation in hydraulic brake feeling while making it less likely for the vehicle to move backward even when road surface conditions change. [Means for solving the problem]

[0007] The control device according to the present disclosure includes: A control device that controls a vehicle drive device mounted on a vehicle that is equipped with a rotating electric machine and a hydraulic brake, When the vehicle stops from a running state with the rotating electric machine rotating in conjunction with the wheels, a first pre-stop control that, when the vehicle speed is equal to or lower than a first reference speed, performs a braking operation by the hydraulic brake in addition to regenerative braking by the rotating electric machine, and controls a torque of the rotating electric machine so that the rotational speed of the rotating electric machine approaches a target rotational speed that is gradually reduced; a second pre-stop control that controls the torque of the rotating electric machine so that the rotation speed of the rotating electric machine approaches a target rotation speed that decreases toward zero when the vehicle speed is equal to or less than a second reference speed that is lower than the first reference speed; Execute.

[0008] According to this configuration, when a traveling vehicle is about to stop, first executing the first pre-stop control can provide a hydraulic brake feeling by using the hydraulic brake in combination. Even if there is variation in the hydraulic pressure for operating the hydraulic brake, this appears as a deviation between the actual rotational speed of the rotating electric machine and the target rotational speed, and the torque of the rotating electric machine is controlled to reduce this deviation, thereby minimizing variation in the hydraulic brake feeling. Furthermore, by executing the second pre-stop control when the vehicle speed has further decreased, the rotational speed of the rotating electric machine can be reduced toward zero in accordance with the target rotational speed set in the second pre-stop control. Even if the road surface conditions (e.g., gradient, surface friction, etc.) change and the rotational speed deviates from the target rotational speed, the torque of the rotating electric machine is controlled to reduce the deviation and bring the rotational speed of the rotating electric machine closer to the target rotational speed, making it less likely that the vehicle will move in reverse. As a result, when stopping control is being performed on a vehicle equipped with a rotating electric motor and hydraulic brakes, it is possible to minimize variation in hydraulic brake feeling and make it less likely for the vehicle to move backward even when road surface conditions change.

[0009] Further features and advantages of the techniques according to the present disclosure will become more apparent from the following description of exemplary and non-limiting embodiments, which proceeds with reference to the drawings. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a vehicle drive device and a control device according to an embodiment; [Figure 2] Control device block diagram [Figure 3] Time chart for each part during stopping control [Figure 4] Control block diagram for determining torque command for a rotating electrical machine [Figure 5] Flowchart showing the processing procedure for vehicle stop control DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the control device will be described with reference to the drawings. As shown in Fig. 1, this control device 1 is a control device for a vehicle drive device that controls a vehicle drive device 3 mounted on a vehicle V. In this embodiment, the vehicle V is described as an electric vehicle (electrically driven vehicle) as an example. That is, the control device 1 of this embodiment is a control device for an electric vehicle drive device.

[0012] In the following description, the term "rotating electric machine" is used as a concept that includes motors (electric motors), generators (electric generators), and motor-generators that function as both motors and generators as needed.

[0013] As shown in FIG. 1, the vehicle drive device 3 includes a rotating electric machine 31, a power transmission device 32, and an output shaft 33. These are housed in a case 35. The rotating electric machine 31 functions as a driving force source for the wheels W. As is well known, the rotating electric machine 31 includes a stator fixed to the case 35, which is a non-rotating member, and a rotor rotatably supported radially inside the stator. The rotating electric machine 31 receives a supply of electric power from an electric storage device (not shown) for power running, or supplies electric power generated by the inertial force of the vehicle or the like to the electric storage device for storage.

[0014] The power transmission device 32 is provided in a power transmission path connecting the rotating electric machine 31 and the wheels W, and transmits the driving force of the rotating electric machine 31 to the wheels W. The power transmission device 32 is configured to include, for example, a speed change mechanism or a differential gear mechanism, and may also be configured to include, for example, a counter drive mechanism. The output shafts 33 function as output members of the vehicle drive device 3, and are provided in pair on the left and right. Each of the pair of output shafts 33 is drivingly connected to the wheels W via, for example, a drive shaft.

[0015] The vehicle V on which the vehicle drive device 3 is mounted is equipped with various components necessary for safely driving the vehicle V with passengers on board. The vehicle V is equipped with, for example, an accelerator pedal, a brake pedal P, a steering wheel, a suspension, wheels W, etc. In particular, the vehicle V of this embodiment is equipped with a hydraulic brake B that operates in conjunction with the operation of the brake pedal P and functions to stop the rotation of the wheels W.

[0016] The control device 1 functions as a core for controlling the operation of each part of the vehicle drive device 3. The control device 1 mainly controls the operation of the rotating electric machine 31 as a driving force source for the wheels W. The control device 1 is configured to include, for example, an inverter circuit including a switching element, a smoothing capacitor, a control board, etc., and may also be configured to include, for example, a boost circuit, etc. In the illustrated example, the control device 1 is provided integrally with a case 35 of the vehicle drive device 3.

[0017] 2, the control device 1 includes an integrated control unit 11, a rotating electrical machine control unit 12, and a stopping control unit 13. Each of these functional units is configured by software (programs) stored in a storage medium such as a memory, or by hardware such as a separately provided arithmetic circuit, or by both. The functional units are configured to be able to exchange information with each other. The control device 1 is also configured to be able to acquire information on the detection results of various sensors (in this example, a first sensor 41 to a fourth sensor 44) provided in each part of the vehicle V.

[0018] The first sensor 41 detects the rotational speed of the rotating electric machine 31 (specifically, the rotor) or a rotating member that rotates integrally with the rotating electric machine 31 (for example, a transmission input member when the power transmission device 32 includes a transmission mechanism). The second sensor 42 detects the rotational speed of the output shaft 33 or a rotating member that rotates integrally with the output shaft 33 (for example, wheels W). The control device 1 can calculate the vehicle speed (travel speed of the vehicle V) based on the detection result by the second sensor 42. Alternatively, the second sensor 42 may directly detect the vehicle speed. The third sensor 43 detects the operation amount (accelerator opening) of an accelerator pedal provided on the vehicle V. The fourth sensor 44 detects the operation amount of a brake pedal P provided on the vehicle V.

[0019] The control device 1 can also calculate the rotational acceleration, which is the rate of change of the rotational speed of each rotating member detected by the first sensor 41 and the second sensor 42, based on the rotational speed of each rotating member detected by the first sensor 41 and the second sensor 42.

[0020] The integrated control unit 11 performs control that integrates various controls necessary for the vehicle V to travel as a whole of the vehicle V. The integrated control unit 11 calculates the torque required to drive the vehicle V (vehicle required torque) based on, for example, vehicle speed information calculated based on the detection result by the second sensor 42 and accelerator opening information detected by the third sensor 43. If the rotating electric machine 31 is the only driving force source for the wheels W as in this embodiment, the vehicle required torque becomes the torque required of the rotating electric machine 31 (rotating electric machine required torque).

[0021] In this embodiment, the integrated control unit 11 calculates the torque (required braking torque) required to decelerate the vehicle V based on, for example, the amount of brake operation detected by the fourth sensor 44. The integrated control unit 11 determines the share of the required braking torque to be contributed by the hydraulic brake B provided on the vehicle and the share of the negative torque output by the rotating electric machine 31.

[0022] The rotating electric machine control unit 12 controls the rotating electric machine 31. The rotating electric machine control unit 12 can execute torque control and rotational speed control of the rotating electric machine 31 according to the running state of the vehicle. The torque control of the rotating electric machine 31 is a control that commands a target torque (for example, a torque according to the above-mentioned rotating electric machine required torque or braking torque) to the rotating electric machine 31 and makes the output torque of the rotating electric machine 31 follow the target torque. The torque control is typically executed by feedforward control.

[0023] The rotational speed control of the rotating electric machine 31 is a control that commands a target rotational speed to the rotating electric machine 31 and adjusts the output torque so that the rotational speed of the rotating electric machine 31 follows the target rotational speed. The rotational speed control is typically performed by feedback control. In the rotational speed control of the rotating electric machine 31, the rotating electric machine control unit 12 can set a target value for the output torque and perform feedforward control, while also setting a target value for the rotational speed and performing feedback control.

[0024] The stopping control unit 13 performs stopping control to gradually decelerate and stop the vehicle V while it is running. The stopping control is executed when the vehicle V stops from a running state with the rotating electric machine 31 rotating in conjunction with the wheels W. The stopping control is executed when, while the vehicle V is running, for example, the driver applies the brakes or the vehicle speed decreases due to road resistance or the like, and it is determined that the vehicle V will stop within a predetermined time. The stopping control unit 13 of this embodiment executes initial deceleration control, first pre-stop control, and second pre-stop control as stopping controls. After executing the initial deceleration control, the stopping control unit 13 executes the first pre-stop control, and then executes the second pre-stop control. The stopping control unit 13 executes the initial deceleration control, the first pre-stop control, and the second pre-stop control in cooperation with the rotating electric machine control unit 12.

[0025] The initial deceleration control is executed after the start condition is met while the vehicle speed is higher than the first reference speed Vs1. Here, the start condition is, for example, that the operation amount (braking operation amount) of the brake pedal P is equal to or greater than the reference operation amount. The reference operation amount is set to an operation amount of the brake pedal P that is expected to cause the vehicle V to stop within a predetermined time thereafter. Furthermore, the first reference speed Vs1 is set to, for example, 3 to 7 km / h. Note that the contents of the start condition and the magnitude of the first reference speed Vs1 mentioned here are merely examples and may be changed as appropriate depending on required specifications, etc.

[0026] In the initial deceleration control, no braking operation is performed by the hydraulic brake B, and only regenerative braking is performed by the rotating electric machine 31. In this initial deceleration control, control is executed to make the torque of the rotating electric machine 31 follow a target torque set to a negative value. Here, the negative target torque is set to the required braking torque. As shown in FIG. 3, the initial deceleration control is executed by feedforward control with the target torque set to a negative value as the target value. By executing such initial deceleration control, it is possible to appropriately decelerate the vehicle V while efficiently regenerating power in the rotating electric machine 31, thereby improving electricity efficiency.

[0027] The first pre-stop control is executed during the period from when the vehicle speed becomes equal to or less than the first reference speed Vs1 until the vehicle speed is higher than a second reference speed Vs2 that is less than the first reference speed Vs1. Here, the second reference speed Vs2 is set to, for example, 1 to 2 km / h. Note that the magnitude of the second reference speed Vs2 mentioned here is merely an example and may be changed as appropriate depending on the required specifications, etc.

[0028] In the first pre-stop control, in addition to regenerative braking by the rotating electric machine 31, a braking operation is performed by the hydraulic brake B. In the first pre-stop control, the braking torque by the hydraulic brake B, which was zero before (i.e., during the initial deceleration control), is gradually increased, and conversely, the regenerative braking torque by the rotating electric machine 31 is gradually decreased. The increase in braking torque by the hydraulic brake B and the decrease in regenerative braking torque by the rotating electric machine 31 are balanced, and the sum of the braking torque by the hydraulic brake B and the regenerative braking torque by the rotating electric machine 31 matches the required braking torque. This makes it possible to provide a hydraulic brake feeling while ensuring the required braking torque.

[0029] In the first pre-stop control, control is executed to adjust the torque of the rotating electric machine 31 so that the rotation speed of the rotating electric machine 31 approaches the gradually decreasing target rotation speed. In this first pre-stop control, feedforward control is executed in combination, with the target torque set to a negative value according to the portion of the required braking force contributed by regenerative braking of the rotating electric machine 31 as the target value, and feedback control is executed in combination, with the torque of the rotating electric machine 31 being controlled so that the rotation speed of the rotating electric machine 31 approaches the gradually decreasing target rotation speed.

[0030] For this reason, the control device 1 of this embodiment includes a feedforward controller (FF controller) 51 and a feedback controller (FB controller) 52, as shown in Fig. 4. The feedforward controller 51 calculates a torque target value (shown as an "FF term" in Fig. 3) according to the portion of the required braking force that is due to regenerative braking of the rotating electric machine 31 (regenerative required torque). The feedback controller 52 calculates an adjustment torque (shown as an "FB term" in Fig. 3) for canceling out the deviation of the actual rotation speed from the target rotation speed of the rotating electric machine 31. The torque command for the rotating electric machine 31 is the sum of these two (shown as "FF+FB" in Fig. 3).

[0031] The feedback control in the first pre-stop control can be, for example, proportional control (P control), proportional-integral control (PI control), or proportional-integral-derivative control (PID control). Among these, a control including an integral term, i.e., proportional-integral control (PI control) or proportional-integral-derivative control (PID control), is preferred because it can eliminate steady-state deviations caused by disturbances and bring the rotation speed of the rotating electric machine 31 closer to the target rotation speed with higher accuracy. In this embodiment, the disturbances that cause deviations of the actual rotation speed of the rotating electric machine 31 from the target rotation speed are mainly variations in the hydraulic pressure of the hydraulic brake B (and thus variations in the braking torque caused by such variations), and since sudden changes are not generally expected, proportional-integral control (PI control) is used.

[0032] By executing feedforward control in the first pre-stop control, the torque of the rotating electric machine 31 can be quickly brought closer to the target torque, and the share of the regenerative braking of the rotating electric machine 31 (required regenerative torque) can be quickly output. Furthermore, by executing feedback control in the first pre-stop control, even if there is variation in the hydraulic pressure of the hydraulic brake B (and therefore variation in the braking torque due to this), variation in the hydraulic brake feeling can be kept small. If there is variation in the hydraulic pressure of the hydraulic brake B, this will appear as a deviation between the actual rotation speed and the target rotation speed of the rotating electric machine 31, and therefore, by using feedback control to adjust the torque of the rotating electric machine 31 to cancel out this deviation, an appropriate total required braking force can be ensured.

[0033] The target rotation speed of the rotating electric machine 31 in the first pre-stop control is set based on at least one of the actual rotation speed and the actual rotation acceleration of the rotating electric machine 31 at the end of the initial deceleration control (i.e., when the vehicle speed has decreased to the first reference speed Vs1). In this embodiment, the target rotation speed is set based on both the actual rotation speed and the actual rotation acceleration of the rotating electric machine 31 at the end of the initial deceleration control. As shown in Fig. 3, the target rotation speed is set so that the actual rotation speed of the rotating electric machine 31 at the end of the initial deceleration control is used as an initial value, and so as to change over time at the same time rate as the actual rotation acceleration of the rotating electric machine 31 at that time.

[0034] The second pre-stop control is executed during a period when the vehicle speed is equal to or lower than the second reference speed Vs2. In the second pre-stop control, regenerative braking by the rotating electric machine 31 is switched over to braking operation by the hydraulic brake B. In the second pre-stop control, the braking torque by the hydraulic brake B, which was relatively small before (i.e., during the first pre-stop control), is increased in a short period of time, and conversely, the regenerative braking torque by the rotating electric machine 31 is reduced in a short period of time. This allows for a clearer hydraulic brake feeling, and ultimately allows the hydraulic brake B to reliably maintain the vehicle V in a stopped state.

[0035] In the second pre-stop control, control is executed to adjust the torque of the rotating electric machine 31 so that the rotation speed of the rotating electric machine 31 approaches a target rotation speed that decreases toward zero. In this second pre-stop control, feedforward control is executed in combination, with the target value being a target torque that is set to approach zero while taking a negative value, and feedback control is executed in combination to adjust the torque of the rotating electric machine 31 so that the rotation speed of the rotating electric machine 31 approaches the target rotation speed that decreases toward zero. In this second pre-stop control, as in the first pre-stop control described above, both the feedforward controller 51 and the feedback controller 52 are used.

[0036] As described above, the feedback controller 52 of this embodiment is configured to execute proportional-integral control (PI control), and the adjustment torque includes a proportional component and an integral component. At the end of the first pre-stop control, an adjustment torque component due to the integral term remains as a component for canceling out the steady-state deviation. Therefore, in this embodiment, the adjustment torque component due to the integral term in the first pre-stop control is reset to zero when transitioning from the first pre-stop control to the second pre-stop control. The torque command value at the end of the first pre-stop control is set as the initial value of the target torque for the feedforward control in the second pre-stop control. In the feedforward control in the second pre-stop control, a torque target is set that approaches zero at a constant time rate, using the torque command value at the end of the first pre-stop control as the initial value.

[0037] By executing feedforward control in the second pre-stop control, the torque of the rotating electric machine 31 is quickly brought close to zero, gradually eliminating regenerative braking by the rotating electric machine 31, and braking operation can be switched to hydraulic brake B early. Furthermore, by executing feedback control in the second pre-stop control, the actual rotational speed of the rotating electric machine 31 decreases while maintaining a positive value. Therefore, when the vehicle V is stopped with the rotating electric machine 31 rotating in conjunction with the wheels W, the wheels W also decrease while maintaining forward rotation. Therefore, even if the road surface conditions (e.g., gradient, surface friction, etc.) change or there is a slight delay in the rise of the hydraulic pressure of the hydraulic brake B, it is possible to make it less likely that the vehicle V will move in reverse.

[0038] The target rotation speed of the rotating electric machine 31 in the second pre-stop control is set based on at least one of the actual rotation speed and the actual rotation acceleration of the rotating electric machine 31 at the end of the first pre-stop control (i.e., when the vehicle speed has decreased to the second reference speed Vs2). In this embodiment, the target rotation speed is set based on both the actual rotation speed and the actual rotation acceleration of the rotating electric machine 31 at the end of the first pre-stop control. As shown in FIG. 3 , the target rotation speed is set so that the actual rotation speed of the rotating electric machine 31 at the end of the first pre-stop control is used as an initial value, and so that it changes over time at the same time rate as the actual rotation acceleration of the rotating electric machine 31 at that time. Furthermore, the target rotation speed is set so that after it has decreased to zero, it is maintained at zero.

[0039] The processing procedure of the vehicle stopping control, which includes the initial deceleration control, the first pre-stop control, and the second pre-stop control, will be described with reference to Fig. 5. When the vehicle V is traveling under normal control and the start condition is met (step #01: Yes), the initial deceleration control is executed (#02). In the initial deceleration control, with the hydraulic brake B inactive, control is executed to make the torque of the rotating electrical machine 31 follow a target torque set according to the required braking torque.

[0040] When the vehicle speed is decreasing due to the execution of the initial deceleration control and the vehicle speed becomes equal to or less than the first reference speed Vs1 (#03: Yes, time t1), the first pre-stop control is initiated. In the first pre-stop control, the braking torque by the hydraulic brake B is gradually increased, and the regenerative braking torque by the rotating electric machine 31 is gradually decreased (#04). Then, feedforward control, which sets a target torque corresponding to the share of regenerative braking by the rotating electric machine 31 as a target value, and feedback control, which controls the torque of the rotating electric machine 31 so that the rotational speed of the rotating electric machine 31 approaches the gradually decreasing target rotational speed, are executed together (#05).

[0041] The vehicle speed continues to decrease while the first pre-stop control is being executed, and when the vehicle speed becomes equal to or less than the second reference speed Vs2 under such circumstances (#06: Yes, time t2), the second pre-stop control is initiated. In the second pre-stop control, the braking torque by the hydraulic brake B is rapidly increased, and the regenerative braking torque by the rotating electric machine 31 is rapidly decreased (#07). Then, feedforward control is executed in which the target torque is set to a target value that gradually approaches zero using the torque command value at the end of the first pre-stop control as the initial value, and feedback control is executed in which the torque of the rotating electric machine 31 is controlled so that the rotational speed of the rotating electric machine 31 approaches the target rotational speed that decreases toward zero (#08).

[0042] When the time during which the vehicle speed remains zero exceeds a certain period of time (#09: Yes), the vehicle V is considered to have come to a complete stop, and the stopping control is terminated.

[0043] Other Embodiments (1) In the above embodiment, an example has been described in which the first pre-stop control executes both feedforward control of the torque of the rotating electric machine 31 and feedback control of the rotation speed of the rotating electric machine 31. However, the present invention is not limited to such a configuration, and the first pre-stop control may execute only feedback control of the rotation speed of the rotating electric machine 31.

[0044] (2) In the above embodiment, an example has been described in which the target rotation speed of the rotating electric machine 31 in the first pre-stop control is set based on both the actual rotation speed and the actual rotation acceleration of the rotating electric machine 31 at the end of the initial deceleration control. However, the present invention is not limited to such a configuration, and the target rotation speed may be set based on only one of the actual rotation speed and the actual rotation acceleration of the rotating electric machine 31 at the end of the initial deceleration control. For example, the actual rotation speed of the rotating electric machine 31 at the end of the initial deceleration control may be set as an initial value, and the target rotation speed may be set so as to change over time at a time change rate close to the actual rotation acceleration of the rotating electric machine 31 at that time. Furthermore, the slope of the target rotation speed may change in a stepwise manner.

[0045] (3) In the above embodiment, the adjustment torque due to the integral term in the feedback control in the first pre-stop control is reset when the first pre-stop control is switched to the second pre-stop control. However, the present invention is not limited to such a configuration, and the adjustment torque due to the integral term may be removed at any time during the second pre-stop control (for example, immediately before the vehicle speed becomes zero).

[0046] (4) In the above embodiment, an example has been described in which the second pre-stop control performs both feedforward control of the torque of the rotating electric machine 31 and feedback control of the rotation speed of the rotating electric machine 31. However, the present invention is not limited to such a configuration, and the second pre-stop control may perform only feedback control of the rotation speed of the rotating electric machine 31.

[0047] (5) In the above embodiment, an example has been described in which the target rotation speed of the rotating electric machine 31 in the second pre-stop control is set based on both the actual rotation speed and the actual rotation acceleration of the rotating electric machine 31 at the end of the first pre-stop control. However, the present invention is not limited to such a configuration, and the target rotation speed may be set based on only one of the actual rotation speed and the actual rotation acceleration of the rotating electric machine 31 at the end of the first pre-stop control. For example, the actual rotation speed of the rotating electric machine 31 at the end of the first pre-stop control may be set as an initial value, and the target rotation speed may be set to change over time at a time change rate close to the actual rotation acceleration of the rotating electric machine 31 at that time. Furthermore, the slope of the target rotation speed may change in a stepwise manner.

[0048] (6) In the above embodiment, an example has been described in which the vehicle required torque and the required braking torque are calculated by the integrated control unit 11 provided in the control device 1. However, the present invention is not limited to such a configuration, and for example, the vehicle required torque and the required braking torque may be calculated by a vehicle ECU provided separately from the control device 1, and the control device 1 may receive this information from the vehicle ECU and perform various controls.

[0049] (7) In the above embodiment, the control device 1 is described as an example of a configuration in which the object to be controlled by the control device 1 is a drive device for an electric vehicle (electrically driven vehicle) that has only a rotating electric machine 31 as a drive power source for the wheels W. However, the control device 1 is not limited to such a configuration, and can also be used to control a drive device for a hybrid vehicle that has an internal combustion engine in addition to the rotating electric machine 31 as a drive power source for the wheels W.

[0050] (8) The configurations disclosed in the above-described embodiments (including the above-described embodiments and other embodiments; the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no contradiction occurs. Regarding other configurations, the embodiments disclosed in this specification are illustrative in all respects and can be appropriately modified within the scope of the present disclosure.

[0051] Summary of the embodiment To summarize the above, the control device according to the present disclosure preferably has the following configurations.

[0052] A control device (1) for controlling a vehicle drive device (3) mounted on a vehicle (V) equipped with a rotating electric machine (31) and a hydraulic brake (B), When the vehicle (V) stops from a traveling state while the rotating electric machine (31) rotates in conjunction with the wheels (W), a first pre-stop control that performs a braking operation by the hydraulic brake (B) in addition to regenerative braking by the rotating electric machine (31) when the vehicle speed is equal to or lower than a first reference speed (Vs1) and controls the torque of the rotating electric machine (31) so that the rotational speed of the rotating electric machine (31) approaches a gradually decreasing target rotational speed; a second pre-stop control for controlling the torque of the rotating electric machine (31) so that the rotation speed of the rotating electric machine (31) approaches a target rotation speed that decreases toward zero when the vehicle speed is equal to or less than a second reference speed (Vs2) that is lower than the first reference speed (Vs1); Execute.

[0053] According to this configuration, when a traveling vehicle (V) is about to stop, first executing the first pre-stop control can provide a hydraulic brake feeling by using the hydraulic brake (B) in combination. Even if there is a variation in the hydraulic pressure for operating the hydraulic brake (B), this appears as a deviation between the actual rotational speed of the rotating electric machine (31) and the target rotational speed. The torque of the rotating electric machine (31) is controlled to reduce the deviation, thereby minimizing the variation in the hydraulic brake feeling. Furthermore, by executing the second pre-stop control when the vehicle speed is further reduced, the rotational speed of the rotating electric machine (31) can be reduced toward zero in accordance with the target rotational speed set in the second pre-stop control. Even if the road surface conditions (e.g., gradient, surface friction, etc.) change and the rotational speed deviates from the target rotational speed, the torque of the rotating electric machine (31) is controlled to reduce the deviation and bring the rotational speed of the rotating electric machine (31) closer to the target rotational speed. This makes it difficult for the vehicle (V) to move in reverse. As a result, when stopping control is being performed on a vehicle (V) equipped with a rotating electric machine (31) and a hydraulic brake (B), it is possible to minimize variations in the hydraulic brake feeling and make it less likely for the vehicle (V) to move backward even when the road surface conditions change.

[0054] In one embodiment, while the vehicle speed is higher than the first reference speed (Vs1), an initial deceleration control is executed to make the torque of the rotating electric machine (31) follow a target torque set to a negative value without performing a braking operation by the hydraulic brake (B); The target rotation speed in the first pre-stop control is preferably set based on at least one of the rotation speed and the rotation acceleration of the rotating electric machine (31) at the end of the initial deceleration control.

[0055] According to this configuration, by executing the initial deceleration control using only regenerative braking of the rotating electric machine (31) while the vehicle speed is higher than the first reference speed (Vs1), it is possible to appropriately decelerate the vehicle (V) and efficiently perform regeneration. Furthermore, since the target rotation speed in the first pre-stop control, which is started when the vehicle speed becomes equal to or lower than the first reference speed (Vs1), is set based on at least one of the rotation speed and the rotation acceleration of the rotating electric machine (31) at the end of the initial deceleration control, it is possible to minimize changes in the behavior of the vehicle (V) when the control mode is transitioned from the initial deceleration control to the first pre-stop control.

[0056] In one embodiment, During execution of each of the first pre-stop control and the second pre-stop control, a feedforward control is also executed, the target torque being set to a value equal to or less than zero; the first pre-stop control is executed by feedback control including at least a proportional term and an integral term, When transitioning from the first pre-stop control to the second pre-stop control, it is preferable to reset the adjustment torque due to the integral term in the first pre-stop control, and set the torque command value at the end of the first pre-stop control to the initial value of the target torque of the feedforward control in the second pre-stop control.

[0057] According to this configuration, in each of the first pre-stop control and the second pre-stop control, the torque of the rotating electric machine (31) can be quickly brought closer to the target torque by the feedforward control, while the feedback control can reduce the variation in the hydraulic brake feeling and make it difficult for the vehicle (V) to move backward even when the road surface condition changes, as described above. Furthermore, since the first pre-stop control includes an integral term in addition to a proportional term, the rotation speed of the rotating electric machine (31) can be brought closer to the target rotation speed with higher accuracy in the first pre-stop control. Furthermore, by resetting the adjustment torque amount by the integral term to zero when transitioning from the first pre-stop control to the second pre-stop control, the influence of the value of the integral term on the second pre-stop control can be reduced, and the second pre-stop control can be appropriately performed.

[0058] In one embodiment, In the second pre-stop control, it is preferable that the regenerative braking torque by the rotary electric machine (31) is gradually decreased and the braking torque by the hydraulic brake (B) is gradually increased.

[0059] According to this configuration, the vehicle (V) can be finally brought to a reliable stop by the braking torque of the hydraulic brake (B).

[0060] It is sufficient for the control device according to the present disclosure to achieve at least one of the above-described effects. [Explanation of symbols]

[0061] 1: control device, 3: vehicle drive device, 11: integrated control unit, 12: rotating electric machine control unit, 13: stopping control unit, 31: rotating electric machine, 32: power transmission device, 33: output shaft, 35: case, 41: first sensor, 42: second sensor, 43: third sensor, 44: fourth sensor, 51: feedforward controller, 52: feedback controller, B: hydraulic brake, P: brake pedal, V: vehicle, Vs1: first reference speed, Vs2: second reference speed, W: wheel

Claims

1. A control device that controls a vehicle drive device mounted on a vehicle that is equipped with a rotating electric machine and a hydraulic brake, When the vehicle stops from a running state with the rotating electric machine rotating in conjunction with the wheels, a first pre-stop control that, when the vehicle speed is equal to or lower than a first reference speed, performs a braking operation by the hydraulic brake in addition to regenerative braking by the rotating electric machine, and controls a torque of the rotating electric machine so that the rotational speed of the rotating electric machine approaches a target rotational speed that is gradually reduced; a second pre-stop control for controlling the torque of the rotating electric machine so that the rotation speed of the rotating electric machine approaches a target rotation speed that decreases toward zero when the vehicle speed is equal to or less than a second reference speed that is lower than the first reference speed; A control device that executes the above.

2. while the vehicle speed is higher than the first reference speed, an initial deceleration control is executed to make the torque of the rotating electrical machine follow a target torque set to a negative value without performing a braking operation by the hydraulic brake; The control device according to claim 1 , wherein the target rotation speed in the first pre-stop control is set based on at least one of the rotation speed and the rotation acceleration of the rotating electric machine at the end of the initial deceleration control.

3. During execution of each of the first pre-stop control and the second pre-stop control, a feedforward control is also executed, the target torque being set to a value equal to or less than zero; the first pre-stop control is executed by feedback control including at least a proportional term and an integral term, 3. The control device according to claim 1, wherein, when transitioning from the first pre-stop control to the second pre-stop control, the adjustment torque due to the integral term in the first pre-stop control is reset, and the torque command value at the end of the first pre-stop control is set to the initial value of the target torque of the feedforward control in the second pre-stop control.

4. 3. The control device according to claim 1, wherein in the second pre-stop control, the regenerative braking torque by the rotary electric machine is gradually reduced and the braking torque by the hydraulic brake is gradually increased.

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