Control device for a vehicle

Abstract

A control device (80) includes a motor control section (70, 33a, 33b) that controls output torque of a motor generator, and a bias torque calculation section (702) that calculates bias torque that needs to be applied to a wheel in order to stop a vehicle on a road surface having a prescribed slope. When stopping the vehicle in motion on the road surface having the prescribed slope, the motor control section controls the output torque of the motor generator so as to gradually approach the bias torque.

Description

[0001] Citation of relevant applications

[0002] This application claims priority to Japanese Patent Application No. 2020-066556, filed on April 2, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a vehicle control device. Background Technology

[0004] Conventionally, there exists a vehicle control device as described in Patent Document 1. The vehicle described in Patent Document 1 is a so-called electric vehicle that moves by transmitting power from an electric generator to the wheels. This vehicle is equipped with a braking device that applies braking force to the wheels using hydraulic pressure. The control device described in Patent Document 1 controls the vehicle's movement by driving the electric generator. Furthermore, this control device controls the vehicle's braking by driving the braking device to apply braking force to the wheels.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2020-22268 Summary of the Invention

[0008] Some vehicles have an ACC (Adaptive Cruise Control) function that automatically controls the vehicle's movement to follow the vehicle in front. In recent years, in vehicles with such ACC function, when the vehicle stops along with the vehicle in front, there is a requirement to stop the vehicle smoothly and as early as possible.

[0009] On the other hand, in the electric vehicle described in Patent Document 1, braking force can be applied to the wheels not only by driving the braking device but also by regenerating the operation of the electric generator. Generally, compared to braking the wheels using hydraulic pressure from the braking device, braking the wheels using the regenerative operation of the electric generator allows for more precise control of the braking torque applied to the wheels and is also advantageous in terms of power consumption. Therefore, it is considered effective to use the braking force of the electric generator to stop the vehicle when automatically driving with the ACC function in the future in an electric vehicle equipped with ACC.

[0010] Furthermore, when using the braking force of an electric generator to stop a vehicle on a slope, the gradient of the slope or the weight of the vehicle can become an obstacle, potentially preventing the vehicle from stopping properly. Specifically, if the braking force of the electric generator is too weak, the vehicle may not be able to stop on a slope. Conversely, if the braking force of the electric generator is too strong, although the vehicle may be able to stop on a slope, the impact during stopping may cause discomfort to the passengers.

[0011] Furthermore, this technical problem is not limited to vehicles with ACC functionality; it is a common technical problem for all types of vehicles that can use the braking force of an electric generator to stop the vehicle.

[0012] The purpose of this disclosure is to provide a vehicle control device that enables smoother parking of a vehicle on an inclined road.

[0013] According to one aspect of this disclosure, a vehicle control device includes an electric generator capable of applying driving and braking forces to the wheels of the vehicle. Braking force is applied to the wheels by regenerating the electric generator when the vehicle is stopped. The control device includes: an electric motor control unit that controls the output torque of the electric generator; and a bias torque calculation unit that calculates the bias torque required to be applied to the wheels to stop the vehicle on a road surface with a predetermined slope. When stopping the vehicle on a road surface with a predetermined slope, the electric motor control unit controls the vehicle to gradually approach the bias torque by making the output torque of the electric generator approach the bias torque.

[0014] According to this structure, when a vehicle is stopped on a road surface with a specified gradient, the output torque of the electric generator gradually changes towards the bias torque, thus reducing the likelihood of impact when the vehicle stops. Furthermore, because the electric generator applies a bias torque to the wheels when the vehicle stops, the vehicle can maintain its stationary state on a road surface with a specified gradient. Therefore, it is possible to stop the vehicle more smoothly on inclined roads. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the structure of the vehicle according to the first embodiment.

[0016] Figure 2 This is a block diagram showing the electrical structure of the vehicle according to the first embodiment.

[0017] Figure 3 This is a block diagram showing the structure of the EVECU in the first embodiment.

[0018] Figure 4It is a mapping diagram used to calculate the normal torque command value T10* based on the accelerator pedal operation position AP, shift position SP, and vehicle speed VC used by the EVECU of the first embodiment.

[0019] Figure 5 (A) and (B) are schematic diagrams showing vehicles traveling on an uphill road and vehicles traveling on a downhill road.

[0020] Figure 6 This is a flowchart illustrating the steps of learning and processing the bias torque performed by the parking adjustment unit of the first embodiment.

[0021] Figure 7 This is a flowchart illustrating a portion of the parking control processing steps performed by the parking adjustment unit of the first embodiment.

[0022] Figure 8 This is a flowchart illustrating a portion of the parking control processing steps performed by the parking adjustment unit of the first embodiment.

[0023] Figure 9 This is a timing diagram showing the shifts in vehicle speed VC, output torque TM of electric generator, acceleration AC, AG, and bias torque T0 of the vehicle in the first embodiment.

[0024] Figure 10 It is a timing diagram showing the vehicle speed VC, parking control mode setting value M, final torque command value T40*, and braking force shift of the vehicle in the first embodiment.

[0025] Figure 11 This is a block diagram showing the structure of the EVECU in the second embodiment.

[0026] Figure 12 It is a mapping diagram calculated based on the vehicle speed VC and bias torque T0 used by the parking adjustment unit in another embodiment to the specified value ΔT. Detailed Implementation

[0027] The implementation of the vehicle control device will now be described with reference to the accompanying drawings. For ease of understanding, the same symbols will be used to label the same components in each drawing whenever possible, and repeated descriptions will be omitted.

[0028] <First Implementation>

[0029] First, a schematic structure of a vehicle equipped with the control device of this embodiment will be described.

[0030] like Figure 1 As shown, the vehicle 10 of this embodiment includes a steering device 20, in-wheel motors 30a and 30b, and braking devices 40a to 40d.

[0031] In the steering system 20, when the driver rotates the steering wheel 21, the steering torque applied to the steering wheel 21 is transmitted to the steering mechanism 23 via the steering shaft 22, thereby changing the steering angle of the right front wheel 13 and the left front wheel 14. The steering system 20 includes a torque sensor 24 and an actuator device 25. The torque sensor 24 detects the steering torque applied to the steering wheel 21 by the driver. The actuator device 25 applies an auxiliary torque to the steering shaft 22 corresponding to the steering torque detected by the torque sensor 24, thereby assisting the driver's steering operation.

[0032] In-wheel motors 30a and 30b are respectively installed in the right rear wheel 11 and the left rear wheel 12. For example... Figure 2 As shown, the in-wheel motors 30a and 30b each include electric generators 31a and 31b, inverter devices 32a and 32b, MG (Motor Generator) ECU (Electronic Control Unit) 33a and 33b, torque sensors 34a and 34b, and rotation sensors 35a and 35b. In this embodiment, torque sensors 34a and 34b correspond to torque detection units.

[0033] The inverter device 32a converts the DC power supplied from the battery installed in the vehicle 10 into three-phase AC power, and supplies the converted three-phase AC power to the electric generator 31a.

[0034] The electric generator 31a operates as a generator when the vehicle 10 is driven. When operating as a generator, the electric generator 31a is driven based on three-phase AC power supplied from the inverter unit 32a. The driving force of the electric generator 31a is transmitted to the wheels 11, causing the wheels 11 to rotate and the vehicle 10 to move. Additionally, the electric generator 31a operates as a generator when the vehicle 10 is braked. When operating as a generator, the electric generator 31a generates electricity through regenerative braking. Braking force is applied to the wheels 11 through this regenerative braking. The three-phase AC power generated by the electric generator 31a is converted into DC power by the inverter unit 32a and used to charge the battery of the vehicle 10.

[0035] The MGECU 33a is centered around a microcomputer with a CPU or memory. The MGECU 33a controls the power supply to the electric generator 31a by executing a program pre-stored in the memory, which drives the inverter device 32a.

[0036] Torque sensor 34a detects the output torque of electric generator 31a and outputs a signal corresponding to the detected torque to MGECU 33a. Rotation sensor 35a detects the rotational speed of the output shaft of electric generator 31a and outputs a signal corresponding to the detected rotational speed to MGECU 33a. MGECU 33a can obtain information on the output torque and rotational speed of electric generator 31a based on the output signals of torque sensor 34a and rotation sensor 35a respectively.

[0037] The electric generator 31b, inverter device 32b, MGECU 33b, torque sensor 34b, and rotation angle sensor 35b of the in-wheel motor 30b operate in the same manner as the components of the in-wheel motor 30a, therefore detailed descriptions of them are omitted.

[0038] like Figure 1 As shown, braking devices 40a to 40d are respectively installed on wheels 11 to 14 of vehicle 10. Braking devices 40a to 40d apply braking force to wheels 11 to 14 based on hydraulic pressure supplied from a hydraulic circuit installed in vehicle 10, thereby braking vehicle 10. For example, friction braking devices can be used as braking devices 40a to 40d, which apply braking force to wheels 11 to 14 by being integral with them and applying friction to the rotating body.

[0039] In the vehicle 10 of this embodiment, the right rear wheel 11 and the left rear wheel 12 function as drive wheels, and the right front wheel 13 and the left front wheel 14 function as driven wheels. Hereinafter, the right rear wheel 11 and the left rear wheel 12 will be collectively referred to as "drive wheels 11 and 12". Next, referring to… Figure 2 The electrical structure of vehicle 10 will be described in detail.

[0040] like Figure 2 As shown, vehicle 10 includes a throttle position sensor 60, a shift position sensor 61, an acceleration sensor 62, a vehicle speed sensor 63, a preceding vehicle detection sensor 64, an operating unit 65, and a brake position sensor 66. Additionally, as components performing various controls, vehicle 10 includes an EV (Electric Vehicle) ECU 70, an ACC (Adaptive Cruise Control) ECU 71, and a brake ECU 72. In this embodiment, the acceleration sensor 62 corresponds to a first acceleration detection unit. Furthermore, Figure 2 The various elements shown constitute the control device 80 of this embodiment.

[0041] The throttle position sensor 60 detects the operating position of the throttle pedal of the vehicle 10 and outputs the signal corresponding to the detected operating position of the throttle pedal to the EVECU 70.

[0042] The shift position sensor 61 detects the operating position of the gear lever of the vehicle 10 and outputs a signal corresponding to the detected gear lever operating position to the EVECU 70. In the vehicle 10 of this embodiment, the operating positions of the gear lever are provided as "D (drive) gear" and "R (reverse) gear".

[0043] Accelerometer 62 detects the acceleration of vehicle 10 in the direction of travel and outputs a signal corresponding to the detected acceleration to EVECU 70. When vehicle 10 accelerates in the direction of travel, acceleration sensor 62 detects positive acceleration. When vehicle 10 decelerates in the direction of travel, acceleration sensor 62 detects negative acceleration.

[0044] The vehicle speed sensor 63 detects the vehicle speed in the direction of travel of the vehicle 10 and outputs the signal corresponding to the detected vehicle speed to the EVECU 70 and ACCECU 71.

[0045] The lead vehicle detection sensor 64 detects the lead vehicle traveling in front of the vehicle 10 and outputs the detected lead vehicle information to the ACCECU 71. As the lead vehicle detection sensor 64, it is possible to use a camera that detects the lead vehicle by photographing the front of the vehicle 10, a millimeter-wave radar device that detects the lead vehicle based on the reflected waves of radio waves radiated in front of the vehicle 10, etc.

[0046] The operation unit 65 is operated by the passengers of the vehicle 10. Using the operation unit 65, for example, it is possible to switch the so-called ACC function (automatic control of the vehicle 10 by following a preceding vehicle) on and off, and to set the driving speed of the vehicle 10 when the ACC function is on. The operation unit 65 sends the operation information to the ACCECU 71.

[0047] The brake position sensor 66 detects the operating position of the brake pedal of the vehicle 10 and outputs a signal corresponding to the detected operating position of the brake pedal to the brake ECU 72.

[0048] Each ECU 70-72 is centered around a microcomputer with a CPU, memory, etc. Each ECU 70-72 can receive and initiate various information via an in-vehicle network 50 such as CAN installed in the vehicle 10.

[0049] The ACCECU 71 performs ACC control of the vehicle 10 by executing a program pre-stored in the memory. Specifically, the ACCECU 71 performs ACC control when the operation unit 65 detects that the ACC function has been activated.

[0050] For example, when the ACC function is enabled, ACCECU 71 sets the ACC flag Fa to the enabled state and then sends the ACC flag Fa to EVECU 70. Conversely, when the ACC function is disabled, ACCECU 71 sets the ACC flag Fa to the disabled state and then sends the ACC flag Fa to EVECU 70. Thus, EVECU 70 can determine whether the ACC function is enabled or disabled based on whether the ACC flag Fa is enabled or disabled.

[0051] Furthermore, when the ACC function is activated, if no preceding vehicle is detected by the preceding vehicle detection sensor 64, the ACCECU 71 sends the first ACC torque command value T21* along with the ACC flag Fa to the EVECU 70. The first ACC torque command value T21* is the target value of the total torque output from the electric generators 31a and 31b of the in-wheel motors 30a and 30b to enable the vehicle 10 to travel at a certain speed set by the operation unit 65. Based on this first ACC torque command value T21*, the EVECU 70 controls the electric generators 31a and 31b of the in-wheel motors 30a and 30b to enable the vehicle 10 to travel at the preset speed.

[0052] Furthermore, when the ACC function is activated, the ACCECU 71 calculates the relative speed or relative distance of the preceding vehicle based on the detection information from the preceding vehicle detection sensor 64 when the preceding vehicle detection sensor 64 detects a preceding vehicle traveling in front of the vehicle 10. The ACCECU 71 calculates the second ACC torque command value T22* based on the relative speed and relative distance of the preceding vehicle, and sends the calculated second ACC torque command value T22* along with the ACC flag Fa to the EVECU 70. The second ACC torque command value T22* is the target value of the total torque output from the electric generators 31a and 31b of the in-wheel motors 30a and 30b to maintain the relative distance between the vehicle 10 and the preceding vehicle at a specified distance. The second ACC torque command value T22* is set to a positive value when it is necessary to accelerate the vehicle 10, and a negative value when it is necessary to decelerate the vehicle 10. The EVECU 70 controls the electric generators 31a and 31b of the in-wheel motors 30a and 30b respectively based on the second ACC torque command value T22*, so that the vehicle 10 can follow the preceding vehicle while maintaining a specified distance.

[0053] Thus, when the ACC function is enabled, the first ACC torque command value T21* or the second ACC torque command value T22*, along with the ACC flag Fa set to the enabled state, is sent from the ACCECU 71 to the EVECU 70. Conversely, when the ACC function is disabled, the ACC flag Fa set to the disabled state is sent from the ACCECU 71 to the EVECU 70.

[0054] The EVECU 70 is the part that comprehensively controls the driving state of the vehicle 10 by executing programs pre-stored in memory. Specifically, such as... Figure 3 As shown, the EVECU 70 has a normal torque command value calculation unit 700, a torque command value adjustment unit 701, a parking adjustment unit 702, and a torque command value distribution unit 703.

[0055] The output signals of the throttle position sensor 60, shift position sensor 61, and vehicle speed sensor 63 are input to the normal torque command value calculation unit 700. Based on the output signals of these sensors, the normal torque command value calculation unit 700 obtains information about the throttle pedal operating position AP, shift position SP, and vehicle speed VC, and uses this information to... Figure 4 The mapping shown is used to calculate the normal torque command value T10* corresponding to the driver's operation on the vehicle 10. The normal torque command value T10* is the target value of the total torque that should be output from the electric generators 31a and 31b of the in-wheel motors 30a and 30b respectively. When the normal torque command value T10* is a positive value, the target value of the total torque that should be output from the electric generators 31a and 31b is the target value of the direction that causes the vehicle 10 to accelerate. When the normal torque command value T10* is a negative value, the target value of the total torque that should be output from the electric generators 31a and 31b is the target value of the direction that causes the vehicle 10 to decelerate. The normal torque command value calculation unit 700 outputs the calculated normal torque command value T10* to the torque command value adjustment unit 701.

[0056] The torque command value adjustment unit 701 receives the normal torque command value T10* calculated by the normal torque command value calculation unit 700, as well as the ACC flag Fa and ACC torque command values ​​T21* and T22* sent from the ACCECU 71. When the ACC flag Fa is in the off state, i.e., the ACC function is off, the torque command value adjustment unit 701 sends the normal torque command value T10* as the basic torque command value T30* to the parking adjustment unit 702. On the other hand, when the ACC flag Fa is in the on state, i.e., the ACC function is on, the torque command value adjustment unit 701 sends either the first ACC torque command value T21* or the second ACC torque command value T22* sent from the ACCECU 71 as the basic torque command value T30* to the parking adjustment unit 702.

[0057] The basic torque command value T30* sent from the torque command value adjustment unit 701 and the ACC flag Fa set by the ACCECU 71 are input to the parking adjustment unit 702. In addition, the output signals of the acceleration sensor 62 and the vehicle speed sensor 63 are input to the parking adjustment unit 702. The parking adjustment unit 702 can obtain information on the vehicle 10's acceleration AS and vehicle speed VC based on the output signals of these sensors. Information on the output torque TMa, TMb and speed ωMa, ωb of the electric generators 31a and 31b is input to the parking adjustment unit 702 from the respective MGECUs 33a and 33b of the in-wheel motors 30a and 30b.

[0058] When the vehicle 10 is accelerating, the adjustment unit 702 sends the basic torque command value T30* as the final torque command value T40* to the torque command value distribution unit 703, regardless of whether the ACC flag Fa is on or off. Similarly, when the vehicle 10 is decelerating and the ACC flag Fa is off, the adjustment unit 702 sends the basic torque command value T30* as the final torque command value T40* to the torque command value distribution unit 703. In contrast, when the vehicle 10 is stopped, the adjustment unit 702 corrects the basic torque command value T30* based on the vehicle 10's acceleration AS, vehicle speed VC, and the respective output torques TMa, TMb and speeds ωMa, ωMb of the electric generators 31a and 31b to mitigate the impact when the vehicle 10 stops. The corrected basic torque command value T30* is then sent to the torque command value distribution unit 703 as the final torque command value T40*.

[0059] The torque command value allocation unit 703 calculates a first torque command value T51* and a second torque command value T52* based on the final torque command value T40* sent from the parking adjustment unit 702. The first torque command value T51* is the target value of the torque to be output from the electric generator 31a of one in-wheel motor 30a, and the second torque command value T52* is the target value of the torque to be output from the electric generator 31b of the other in-wheel motor 30b. For example, when the steering angle of the steering wheel 21 is "0°", i.e., when the vehicle 10 is traveling straight, the torque command value allocation unit 703 sets each torque command value T51* and T52* by equally dividing the final torque command value T40* into the first torque command value T51* and the second torque command value T52*. Furthermore, when the steering angle of the steering wheel 21 is a value other than "0°", the torque command value allocation unit 703 calculates the torque distribution rate for each of the electric generators 31a and 31b based on the steering angle. Then, the torque command value allocation unit 703 sets a first torque command value T51* and a second torque command value T52* based on the calculated torque distribution ratio and the final torque command value T40*. The torque command value allocation unit 703 sends the set first torque command value T51* and second torque command value T52* to the MGECUs 33a and 33b of the in-wheel motors 30a and 30b, respectively.

[0060] In the in-wheel motor 30a, when the MGECU 33a receives a first torque command value T51* sent from the torque command value distribution unit 703, it calculates a power-on control value based on the first torque command value T51*, and drives the inverter device 32a based on the calculated power-on control value. Thus, by supplying power corresponding to the power-on control value from the inverter device 32a to the electric generator 31a, the electric generator 31a outputs torque corresponding to the first torque command value T51*. Similarly, in the in-wheel motor 30b, the electric generator 31b outputs torque corresponding to the second torque command value T52*.

[0061] Thus, in the vehicle 10 of this embodiment, the EVECU 70 functions as a first control unit that sets the torque command value, and the MGECUs 33a and 33b function as a second control unit that controls the energization of the electric generators 31a and 31b. Furthermore, the EVECU 70 and MGECUs 33a and 33b constitute an electric motor control unit that controls the output torque of the electric generators 31a and 31b.

[0062] like Figure 2As shown, the brake ECU 72 controls the braking devices 40a to 40d by executing a program pre-stored in the memory. Specifically, when the brake ECU 72 detects that the brake pedal is depressed based on the operating position of the brake pedal detected by the brake position sensor 66, it drives the braking devices 40a to 40d to apply braking force to each wheel 11 to 14.

[0063] Additionally, the brake ECU 72, upon detecting that the brake pedal has been pressed, if... Figure 3 As shown, the torque command value adjustment unit 701 sends the braking torque command value T60* to the EVECU 70. The braking torque command value T60* is the target value of the total braking torque that should be output from the electric generators 31a and 31b of the in-wheel motors 30a and 30b to decelerate the vehicle 10. When the braking torque command value T60* is sent from the brake ECU 72, the torque command value adjustment unit 701 prioritizes the braking torque command value T60* over the normal torque command value T10* and the ACC torque command values ​​T21* and T22*, and sends the braking torque command value T60* as the basic torque command value T30* to the parking adjustment unit 702. The parking adjustment unit 702 sends the basic torque command value T30*, set as the braking torque command value T60*, to the torque command value distribution unit 703. The torque command value distribution unit 703 sends a first torque command value T51* and a second torque command value T52*, corresponding to the braking torque command value T60*, to the MGECUs 33a and 33b of the in-wheel motors 30a and 30b, respectively. Based on the first torque command value T51* and the second torque command value T52*, the MGECUs 33a and 33b control the energization of the electric generators 31a and 31b, thereby causing the electric generators 31a and 31b to perform regenerative operation. As a result, braking force corresponding to the braking torque command value T60* is applied from the electric generators 31a and 31b to the drive wheels 11 and 12.

[0064] In this way, the brake ECU 72 applies braking force to each wheel 11-14 through the braking devices 40a-40d, and applies braking force to the drive wheels 11-12 through the electric generators 31a and 31b, thereby stopping the vehicle 10. In this embodiment, the brake ECU 72 is equivalent to the brake control unit.

[0065] Next, the correction principle of the basic torque command value T30* executed by the parking adjustment unit 702 when the ACC function is turned on will be explained.

[0066] like Figure 5As shown in (A), when parking vehicle 10 on an uphill road with a slope θ, gravity exerts a backward force on vehicle 10. Therefore, if the prescribed torque in the driving direction is not applied to wheels 11-14, vehicle 10 cannot maintain its stationary state. Similarly, as Figure 5 As shown in (B), when the vehicle 10 is stopped on a downhill road with a slope θ, the force in the direction of travel will be applied to the vehicle 10 due to the influence of gravity. Therefore, if the prescribed torque in the braking direction is not applied to the wheels 11 to 14, the vehicle 10 cannot maintain a stopped state.

[0067] In addition, the following will be as follows: Figure 5 The road surfaces with a slope θ shown in (A) and (B) of 5 are called "sloping roads". In addition, the slope θ of a flat road is set to "0°", with a positive angle representing the angle between an uphill slope and a flat road, and a negative angle representing the angle between a downhill slope and a flat road.

[0068] like Figure 5 As shown in (A) and (B), in order to stop the vehicle 10 on a road surface with a slope θ, a predetermined offset torque must be applied to the wheels 11 to 14. Therefore, the parking adjustment unit 702 of this embodiment first learns the offset torque that can maintain the vehicle 10 in a stopped state on a road surface with a slope while the vehicle 10 is in motion. Then, when stopping the vehicle 10, the parking adjustment unit 702 applies braking torque to the drive wheels 11 and 12 by regenerating the electric generators 31a and 31b to decelerate the vehicle 10, and at the same time corrects the final torque command value T40* by gradually bringing the torque applied to the drive wheels 11 and 12 from the electric generators 31a and 31b closer to the offset torque. As a result, at the point in time when the vehicle 10 stops, the braking torque applied to the drive wheels 11 and 12 becomes the offset torque, and therefore, the vehicle 10 can maintain a stopped state. In addition, by gradually bringing the braking torque applied to the drive wheels 11 and 12 closer to the bias torque, the impact when the vehicle 10 stops can also be mitigated.

[0069] In addition, Figure 5 When stopping vehicle 10 on an uphill road surface as shown in (A), a torque in the direction of travel of vehicle 10 needs to be applied to the drive wheels 11 and 12. Therefore, the bias torque is a positive value. Additionally, in Figure 5 When stopping vehicle 10 on a downhill road surface as shown in (B), a torque in the reverse direction of vehicle 10 needs to be applied to the drive wheels 11 and 12. Therefore, the bias torque is a negative value. Furthermore, the larger the absolute value of the slope θ, the larger the absolute value of the bias torque. Thus, there is a correlation between the bias torque and the slope θ.

[0070] Next, the calculation principle of the bias torque will be explained.

[0071] like Figure 5 As shown in (A) and (B), when vehicle 10 is traveling on a road surface with a slope θ, the following equation f1 holds true in vehicle 10. Furthermore, in equation f1, "TM" represents the total output torque of electric generators 31a and 31b, "W" represents the vehicle weight, "g" represents gravitational acceleration, "TL" represents the rolling resistance on a flat road, "I" represents the vehicle's moment of inertia, and "AC" represents the acceleration of vehicle 10.

[0072] TM-W·g·sinθ-TL=I·AC(f1)

[0073] Furthermore, the vehicle weight W includes not only the weight of the vehicle 10 itself, but also the total weight of the passengers riding in the vehicle 10. Acceleration AC represents the acceleration of the vehicle 10 in the direction of travel.

[0074] Here, since vehicle 10 is traveling at a low speed just before coming to a stop, the rolling resistance TL on a flat road can be considered approximately zero. Furthermore, the term "W·g·sinθ" corresponds to the bias torque required to maintain vehicle 10 at a stop on a sloping road surface. Therefore, if the bias torque is set to "T0", equation f2 can be obtained from equation f1.

[0075] T0 = ​​TM - I·AC(f2)

[0076] Furthermore, when vehicle 10 is stationary or about to stop, in equation f1, the total output torque TM of the electric generators 31a and 31b is approximately zero, and the rolling resistance TL of the flat road is also approximately zero. Additionally, the vehicle 10 is subjected to only gravity. Therefore, when vehicle 10 is stationary or about to stop, the following equation f3 holds true. In equation f3, "AG" represents the acceleration component of gravitational acceleration in the vehicle's direction of travel.

[0077] -W·g·sinθ=I·AG(f3)

[0078] Therefore, when vehicle 10 is stopped or about to stop, the bias torque T0 can be calculated using the following formula f4.

[0079] T0 = ​​-I·AG(f4)

[0080] On the other hand, the acceleration detected by the accelerometer 62 includes not only the acceleration in the direction of travel of the vehicle 10, but also the acceleration component of the vehicle's direction of travel due to gravitational acceleration. Here, when the vehicle 10 is stationary or about to stop, the acceleration in the direction of travel of the vehicle 10 can be considered approximately zero. Therefore, the acceleration AS detected by the accelerometer 62 is only the acceleration component AG of the vehicle's direction of travel due to gravitational acceleration. Therefore, the acceleration AS detected by the accelerometer 62 can be directly used as the acceleration component AG of the vehicle's direction of travel due to gravitational acceleration in Equation f4. Thus, in this embodiment, the acceleration AS detected by the accelerometer 62 is equivalent to the acceleration component AG of the vehicle's direction of travel due to gravitational acceleration, i.e., the second acceleration. Furthermore, the accelerometer 62 is equivalent to a second acceleration detection unit.

[0081] Furthermore, the acceleration of vehicle 10 is related to the rotational acceleration of electric generators 31a and 31b. Therefore, based on the changes in the rotational speeds ωMa and ωMb of electric generators 31a and 31b over time detected by the rotation sensors 35a and 35b of the in-wheel motors 30a and 30b—in other words, the differential values ​​of the rotational speeds ωMa and ωMb of electric generators 31a and 31b—the acceleration AC of vehicle 10 can be calculated. This calculation of the acceleration AC of vehicle 10 based on the differential values ​​of the rotational speeds ωMa and ωMb of electric generators 31a and 31b can be performed, for example, by the EVECU 70. Thus, in this embodiment, the rotation sensors 35a and 35b correspond to the rotational speed detection unit. Additionally, the acceleration AC of vehicle 10 calculated based on the differential values ​​of the rotational speeds ωMa and ωMb of electric generators 31a and 31b corresponds to the first acceleration. Furthermore, the EVECU 70 is equivalent to a first acceleration detection unit that calculates the acceleration AC of the vehicle 10 based on the rotational speeds ωMa and ωMb detected by the rotational sensors 35a and 35b.

[0082] Next, refer to Figure 6 The specific steps for learning and processing the bias torque T0 executed by the parking adjustment unit 702 using the above principle will be explained. Furthermore, the parking adjustment unit 702 repeatedly executes the process at a predetermined cycle. Figure 6 The processing shown.

[0083] like Figure 6 As shown, firstly, as part of step S10, when parking, the adjustment unit 702 determines whether the vehicle speed VC detected by the vehicle speed sensor 63 is above a predetermined speed Vth10. The predetermined speed Vth10 is preset to determine whether the vehicle 10 is in a stopped state or whether the vehicle 10 is about to stop. The predetermined speed Vth10 is, for example, set to "1 [km / h]".

[0084] When the parking adjustment unit 702 makes a positive determination in step S10, that is, when the vehicle speed VC is a predetermined speed Vth10 or higher, it performs the driving learning process as the process in step S11. Specifically, the parking adjustment unit 702 calculates the acceleration AC of the vehicle 10 using a calculation formula or mapping based on at least one of the rotational speeds ωMa and ωMb of the electric generators 31a and 31b detected by the rotation sensors 35a and 35b of the in-wheel motors 30a and 30b, respectively. In addition, the parking adjustment unit 702 calculates the total output torque TM of the electric generators 31a and 31b by adding the output torques TMa and TMb of the electric generators 31a and 31b detected by the torque sensors 34a and 34b of the in-wheel motors 30a and 30b. When the vehicle is parked, the adjustment unit 702 calculates the bias torque T0 using the above formula f2 based on the acceleration AC of the vehicle 10 obtained in this way, the total output torque TM of the electric generators 31a and 31b, and the inertia I of the vehicle 10 stored in the memory of the EVECU 70.

[0085] On the other hand, if the parking adjustment unit 702 makes a negative judgment in step S10, that is, if the vehicle speed VC is less than the specified speed Vth, then as part of step S12, it performs parking learning processing. Specifically, the parking adjustment unit 702 uses the acceleration AS detected by the acceleration sensor 62 as the acceleration component AG of the vehicle's direction of travel under gravitational acceleration, and calculates the bias torque T0 using the above-mentioned formula f4.

[0086] When the parking adjustment unit 702 has performed the processing in step S11 or step S12, as part of step S13, it performs filtering processing on the calculated bias torque T0. This filtering processing is, for example, based on a low-pass filter with a time constant set to approximately 1 [s]. After storing the bias torque T0 calculated in step S13 in its memory, the parking adjustment unit 702 temporarily terminates the process. Figure 6 The processing shown.

[0087] Thus, in this embodiment, the adjustment unit 702 during parking is equivalent to the bias torque calculation unit that calculates the bias torque T0.

[0088] Next, refer to Figure 7 and Figure 8 The specific steps of parking control performed by the parking time adjustment unit 702 are explained. Furthermore, the parking time adjustment unit 702 repeatedly performs this operation at a predetermined cycle. Figure 7 and Figure 8 The processing shown.

[0089] like Figure 7 As shown, firstly, as part of step S20, the parking adjustment unit 702 determines whether the ACC function is enabled based on the ACC flag Fa sent from the ACCECU 71. If the parking adjustment unit 702 makes a negative determination in step S20, i.e., the ACC function is disabled, it determines that parking control corresponding to the inclined road is not required, and executes the processing after step S32. Specifically, if, as part of step S32, the parking adjustment unit 702 requests the brake ECU 72 to operate the braking devices 40a to 40d, it cancels the request. Furthermore, as part of step S33 following step S32, the parking adjustment unit 702 sets the parking control mode setting value M to "0", and as part of the subsequent step S34, the parking adjustment unit 702 initializes the value of the counter C to "0". In addition, as part of step S35b, the parking adjustment unit 702 sets the parking torque command value TS* to the current basic torque command value T30*. Additionally, as a result of step S35 Figure 8 In step S36, the parking adjustment unit 702 determines whether the parking control mode setting value M satisfies "M≥1". In this case, since the parking control mode setting value M was set to "0" in step S33, the parking adjustment unit 702 performs a negative determination in step S36. Therefore, as part of step S38, the parking adjustment unit 702 temporarily terminates the process after setting the final torque command value T40* to the basic torque command value T30*. Figure 7 and Figure 8 The processing shown.

[0090] like Figure 7 As shown, if a positive judgment is made in step S20, then as part of step S21, the parking adjustment unit 702 determines whether the basic torque command value T30* is below a predetermined value Tth. The predetermined value Tth is preset to determine whether deceleration of the vehicle 10 is required and is stored in the memory of the EVECU 70. The predetermined value Tth is, for example, set to "0". If a negative judgment is made in step S21, that is, if deceleration of the vehicle 10 is not required, then steps S32 to S36 and S38 are executed.

[0091] Furthermore, if a positive judgment is made in step S21, then as part of step S22, the parking adjustment unit 702 determines whether the vehicle speed VC is less than a predetermined speed Vth11. The predetermined speed Vth11 is preset to determine whether the vehicle 10 is traveling at a low speed and is stored in the memory of the EVECU 70. The predetermined speed Vth11 is, for example, set to "3 [km / h]". In this embodiment, the predetermined speed Vth11 corresponds to a predetermined control start speed. If a negative judgment is made in step S22, i.e., if the vehicle speed VC is greater than or equal to the predetermined speed Vth11, then steps S33 to S36 and S38 are executed.

[0092] Thus, when the ACC function is off, and when no deceleration is required for vehicle 10, or when vehicle 10 is traveling at a speed above a specified speed Vth11, the final torque command value T40* is set to the basic torque command value T30* by executing step S38. Therefore, driving force or braking force corresponding to the basic torque command value T30* is applied from the electric generators 31a and 31b to the drive wheels 11 and 12.

[0093] On the other hand, if the parking adjustment unit 702 makes a positive determination in all the processes of steps S20 to S22, that is, if the ACC function is on and the vehicle 10 is required to decelerate and the vehicle speed VC is less than the specified speed Vth11, then the processing after step S23 is executed. Specifically, as a process of step S23, the parking adjustment unit 702 sets the parking control mode setting value M to "1", and as a process of step S24, the parking adjustment unit 702 corrects the parking torque command value TS* based on the following formula f5. In formula f5, TS(i-1) represents the previous value of the parking torque command value TS*. In addition, "ΔT" is a preset value and is stored in the memory of the EVECU 70.

[0094] TS*=TS(i-1)+ΔT(f5)

[0095] As part of the processing following step S24, step S25 involves the parking adjustment unit 702 determining whether the parking torque command value TS* is greater than or equal to the bias torque T0 stored in the memory. If a negative determination is made in step S25, i.e., if the parking torque command value TS* is less than the bias torque T0, then... Figure 8 In step S36 shown, the adjustment unit 702 determines whether the parking control mode setting value M satisfies "M≥1" during parking. In this case, since... Figure 7In step S23, the parking control mode setting value M is set to "1". Therefore, the parking adjustment unit 702 makes an affirmative determination in step S36. Thus, as part of step S37, after setting the final torque command value T40* to the parking torque command value TS*, the parking adjustment unit 702 temporarily terminates the process. Figure 7 and Figure 8 The processing shown.

[0096] Subsequently, during the period from which the parking adjustment unit 702 makes a positive determination in step S25, that is, until the parking torque command value TS* reaches the bias torque T0, the processing of step S24 is repeatedly executed. Therefore, the parking torque command value TS* gradually increases towards the bias torque T0. During this period, the parking adjustment unit 702 executes the processing of step S37, setting the final torque command value T40* as the parking torque command value TS*. Therefore, the total output torque TM of the electric generators 31a and 31b changes towards the bias torque T0.

[0097] Subsequently, when the parking torque command value TS* reaches the bias torque T0, the parking adjustment unit 702 makes a positive determination in step S25, sets the parking torque command value TS* to the bias torque T0 as the next step S26, and increments the value of the counter C as the next step S27. Then, as the next step S28, the parking adjustment unit 702 determines whether the value of the counter C is above or above a first threshold Cth11. The first threshold Cth11 is set to a value that can determine whether a first predetermined time T11 has elapsed since the time point in step S26 when the parking torque command value TS* was set to the bias torque T0, and is stored in the memory of the EVECU 70. This first predetermined time T11 is, for example, "1 [s]".

[0098] If the adjustment unit 702 makes a negative judgment in step S28, that is, if the first predetermined time T11 has not elapsed since the time point when the parking torque command value TS* was set to the bias torque T0, then... Figure 8 In step S36, a negative judgment is made, and step S37 is executed. Therefore, during the period from the time point when the parking torque command value TS* is set to the bias torque T0 until the first predetermined time T11 has elapsed, the parking torque command value TS* and the final torque command value T40* are maintained at the bias torque T0.

[0099] Then, after a first predetermined time T11 has elapsed since the time point at which the parking torque command value TS* was set to the bias torque T0, the parking adjustment unit 702... Figure 7In the process shown in step S28, a positive judgment is made, and this is used as the basis for subsequent... Figure 8 In step S29, the parking control mode setting value M is set to "2". Furthermore, in the subsequent step S30, the adjustment unit 702 requests the brake ECU 72 to activate the braking devices 40a-40d. Based on this request, the brake ECU 72 activates the braking devices 40a-40d, thereby enabling the vehicle 10 to remain stationary on an inclined road by applying braking force from the braking devices 40a-40d to each wheel 11-14.

[0100] As a follow-up to step S30, step S31 involves the parking adjustment unit 702 determining whether the value of counter C is greater than or equal to a second threshold Cth12. The second threshold Cth12 is set to a value that determines whether a second predetermined time T12 has elapsed since the execution of step S30, i.e., since the braking request was made to the brake ECU 72, and is stored in the memory of the EVECU 70. This second predetermined time T12 is a time delay that takes into account the time delay from the braking request made to the brake ECU 72 until sufficient braking force is applied to the wheels 11-14, and is, for example, "2 [s]". If the parking adjustment unit 702 makes a negative determination in step S31, i.e., if the second predetermined time T12 has not elapsed since the braking request was made to the brake ECU 72, a negative determination is made in step S36, and step S37 is executed. Therefore, during the period from the time when the brake ECU 72 made a braking request until the second predetermined time T12 has elapsed, the torque command value TS* at the time of stopping is maintained at the bias torque T0.

[0101] Subsequently, after a second predetermined time T12 elapses from the point when the brake ECU 72 made a braking request, the parking adjustment unit 702 makes a positive determination in the processing of step S31 and executes... Figure 7 The processing after step S33 is shown. Specifically, as part of step S33, the parking adjustment unit 702 sets the parking control mode setting value M to "0", and as part of the subsequent step S34, the parking adjustment unit 702 initializes the value of the counter C to "0". Furthermore, as part of step S35b, the parking adjustment unit 702 sets the parking torque command value TS* to the current basic torque command value T30*. In this case, since the basic torque command value T30* is "0" or a value near "0", the parking torque command value TS* is set to "0" or a value near "0". Afterwards, the parking adjustment unit 702... Figure 8When a negative judgment is made in step S36, as part of step S38, the final torque command value T40* is set to the basic torque command value T30*, and the process is temporarily terminated. Figure 7 and Figure 8 The processing shown.

[0102] Next, refer to Figure 9 and Figure 10 An example of the operation of the vehicle 10 in this embodiment will be described.

[0103] like Figure 9 As shown, suppose that during the period from time t10 to time t11, vehicle 10 travels downhill, then during the period from time t11 to time t12, vehicle 10 travels on a flat road, and after time t12, vehicle 10 travels uphill. If the accelerator pedal is kept depressed for a certain amount after time t10, then... Figure 9 As shown in (B), the total output torque TM of the electric generators 31a and 31b remains at a constant value. Therefore, the vehicle speed VC is as follows: Figure 9 As shown in (A), it moves as indicated. – Specifically, during the period from time t10 to time t11 when vehicle 10 is traveling downhill, gravity acts on vehicle 10 in the direction of travel, therefore, the vehicle speed VC gradually increases. Furthermore, during the period from time t11 to time t12, gravity acts on vehicle 10 in a direction orthogonal to the direction of travel, therefore, the vehicle speed VC is maintained at a certain speed. Moreover, after time t12, gravity acts on vehicle 10 in the reverse direction, therefore, the vehicle speed VC gradually decreases.

[0104] Vehicle speed VC Figure 9 The result of the change shown in (B) is as follows: Figure 9 As shown by the dashed line in (C), during the period from time t10 to time t11, the acceleration AC of vehicle 10 increases with a positive value, and during the period from time t11 to time t12, the acceleration AC of vehicle 10 increases with a value of "0". Furthermore, after time t12, the acceleration AC of vehicle 10 increases with a negative value. On the other hand, the acceleration AS detected by the acceleration sensor 62 includes not only the acceleration AC of vehicle 10 but also gravitational acceleration; therefore, the acceleration AS is as follows... Figure 9 It moves as shown by the solid line in (C).

[0105] When parking, the adjustment unit 702 is based on, for example Figure 9 The acceleration AC of the vehicle 10 being pushed as shown in (C) and as shown in (C) Figure 9The total output torque TM of the electric generators 31a and 31b, which are shifted as shown in (B), is obtained by learning the bias torque T0 using the above formula f2, as follows: Figure 9 The bias torque T0 is obtained as shown in (D).

[0106] Next, refer to Figure 10 This section describes an example of the actions of vehicle 10, with ACC function enabled, when parking uphill.

[0107] When vehicle 10 is traveling uphill, in order to stop vehicle 10 based on the driving status of the preceding vehicle, ACCECU 71 sends a second ACC torque command value T22*, set to a negative value, to EVECU 70. In this case, since the basic torque command value T30* is set as the second ACC torque command value T22*, and this basic torque command value T30* is directly used as the final torque command value T40*, the final torque command value T40* is set as the second ACC torque command value T22*. If the moment when the final torque command value T40* is set as the second ACC torque command value T22* is set to "t20", then as follows... Figure 10 As shown in (C), the final torque command value T40* is set to a negative value at time t20. Therefore, due to the regenerative operation of the electric generators 31a and 31b, braking force is applied to the drive wheels 11 and 12. As a result, as... Figure 10 As shown in (A), the vehicle speed VC gradually decreases. At this time, as... Figure 10 As shown in (B), the parking control mode setting value M is "0".

[0108] Then, if at time t21 the vehicle speed VC decreases to the specified speed Vth11, then as follows Figure 10 As shown in (B), the parking control mode setting value M is set to "1". Furthermore, the parking torque command value TS* is calculated based on the above formula f5, and the calculated parking torque command value TS* is used as the final torque command value T40*. Therefore, as... Figure 10 As shown in (C), after time t21, the final torque command value T40* gradually increases toward the bias torque T0 with a slope ΔT.

[0109] Then, if the torque command value TS* reaches the bias torque T0 when stopping at time t22, the stopping torque command value TS* is fixed at the bias torque T0, and this stopping torque command value TS* is used as the final torque command value T40*. Therefore, as Figure 10 As shown in (C), after time t22, the final torque command value T40* remains at the bias torque T0.

[0110] Then, at time point t23, which is the first predetermined time T11 elapsed from time t22, as... Figure 10 As shown in (B), the parking control mode setting value M is set to "2". At time t23, a request is made to the brake ECU 72 to activate the braking devices 40a to 40d. Therefore, as... Figure 10 As shown in (D), after time t23, the braking force applied from braking devices 40a to 40d to wheels 11 to 14 gradually increases. Then, at time t24, after a second predetermined time T12 has elapsed from time t23, the final torque command value T40* is returned to the basic torque command value T30*, as shown in (D). Figure 10 As shown in (C), the final torque command value T40* is set to, for example, "0". That is, the braking force applied from the electric generators 31a and 31b to the drive wheels 11 and 12 is released. At time t24, as... Figure 10 As shown in (D), since braking force is applied to wheels 11-14 from braking devices 40a-40d, vehicle 10 is able to maintain a stationary state.

[0111] According to the above description, the control device 80 of the vehicle 10 of this embodiment can achieve the following functions and effects (1) to (6).

[0112] (1) When the vehicle 10 is stopped on a road surface with a specified gradient θ, the EVECU 70 and MGECUs 33a and 33b control the vehicle by gradually bringing the total output torque TM of the electric generators 31a and 31b closer to the bias torque T0. According to this structure, since the total output torque TM of the electric generators 31a and 31b gradually changes towards the bias torque T0, it is less likely to cause a shock when the vehicle 10 stops. Furthermore, when the vehicle 10 stops, since the bias torque T0 is applied from the electric generators 31a and 31b to the drive wheels 11 and 12, the vehicle 10 can maintain a stopped state on a road surface with a specified gradient θ. Therefore, it is possible to stop the vehicle 10 more smoothly on an inclined road.

[0113] (2) In Figure 6 In the processing shown, when the vehicle speed VC is above the specified speed Vth10, the parking adjustment unit 702 calculates the bias torque T0 based on the total output torque TM of the electric generators 31a and 31b and the acceleration AC of the vehicle 10, according to equation f2 above. Furthermore, when the vehicle speed VC is less than the specified speed Vth10, the parking adjustment unit 702 calculates the bias torque T0 based on the acceleration AS detected by the acceleration sensor 62, according to equation f4 above. With this structure, the bias torque T0 can be easily calculated.

[0114] (3) The EVECU 70 calculates the acceleration AC of the vehicle 10 based on the rotational speeds ωMa and ωMb of the electric generators 31a and 31b detected by the rotation sensors 35a and 35b. Based on this structure, the acceleration AC of the vehicle 10 can be easily calculated.

[0115] (4) When parking, the adjustment unit 702 operates at a predetermined cycle. Figure 6 The calculation of the bias torque T0 is shown, and a low-pass filter-based filtering process is applied to the bias torque T0 calculated at a specified period. According to this structure, since the bias torque T0 can be smoothed, a more appropriate bias torque T0 with suppressed external interference can be obtained.

[0116] (5) When the vehicle speed VC is less than the specified speed Vth11, EVECU 70 and MGECU 33a, 33b begin to control the total output torque TM of the electric generators 31a, 31b to gradually approach the bias torque T0. According to this structure, since the control to gradually approach the bias torque T0 of the total output torque TM of the electric generators 31a, 31b can be performed when the vehicle 10 is more likely to stop, this control can be performed at a more appropriate time.

[0117] (6) When braking force is continuously applied to the drive wheels 11 and 12 from the electric generators 31a and 31b to maintain the vehicle 10 in a stationary state, the continued operation of the electric generators 31a and 31b may increase power consumption. To address this, in this embodiment, after the output torques TMa and TMb of the electric generators 31a and 31b reach the bias torque T0, the EVECU 70 requests the brake ECU 72 to apply braking force to the wheels 11 and 14 from the braking devices 40a to 40d, and stops the electric generators 31a and 31b. According to this structure, by applying braking force to the wheels 11 and 14 from the braking devices 40a to 40d, the vehicle 10 can be kept stationary, and by stopping the electric generators 31a and 31b, power consumption can be reduced.

[0118] <Second Implementation>

[0119] Next, a second embodiment of the control device 80 for the vehicle 10 will be described. Hereinafter, the description will focus on the differences between the control device 80 and the first embodiment.

[0120] like Figure 11As shown, in the EVECU 70 of this embodiment, the basic torque command value T30* calculated by the torque command value adjustment unit 701 is input to the torque command value allocation unit 703. The torque command value allocation unit 703 calculates a first torque command value T51* and a second torque command value T52* based on the basic torque command value T30*. The first torque command value T51* is the target value of the torque to be output from the electric generator 31a of one in-wheel motor 30a, and the second torque command value T52* is the target value of the torque to be output from the electric generator 31b of the other in-wheel motor 30b. The torque command value allocation unit 703 sends the set first torque command value T51* and second torque command value T52* to the MGECUs 33a and 33b of the in-wheel motors 30a and 30b, respectively.

[0121] The MGECUs 33a and 33b of the in-wheel motors 30a and 30b respectively have parking adjustment units 330a and 330b and power-on control units 331a and 331b.

[0122] The parking adjustment unit 330a receives a first torque command value T51* sent from the torque command value allocation unit 703 and an ACC flag Fa sent from the ACCECU 71. Based on the output signals from the acceleration sensor 62, vehicle speed sensor 63, torque sensors 34a, 34b, and rotation sensor 35a, the parking adjustment unit 330a acquires information on the vehicle 10's acceleration AS, vehicle speed VC, output torque TMa, TMb of the electric generators 31a, 31b, and rotational speed ωMa. Based on this information, the parking adjustment unit 330a performs processing similar to that of the parking adjustment unit 702 in the first embodiment, thereby correcting the first torque command value T51* and sending the corrected first torque command value T51* to the power-on control unit 331a. The power-on control unit 331a drives the inverter device 32a based on the corrected first torque command value T51*, thereby controlling the power-on of the electric generator 31a. Thus, the electric generator 31a outputs torque corresponding to the corrected first torque command value T51*.

[0123] Furthermore, the parking adjustment unit 330b and the power control unit 331b of the in-wheel motor 30b located on the other side operate in the same manner as the parking adjustment unit 330a and the power control unit 331a located on the in-wheel motor 30a, so their detailed descriptions are omitted.

[0124] Even with such a structure, the control device 80 can control the vehicle 10 to stop on a road surface with a specified slope θ by gradually bringing the total output torque TM of the electric generators 31a and 31b closer to the bias torque T0.

[0125] The control device 80 of the vehicle 10 according to the above-described embodiment can further achieve the following functions and effects (7).

[0126] (7) The MGECUs 33a and 33b of the in-wheel motors 30a and 30b are controlled in such a way that the total output torque TM of the electric generators 31a and 31b gradually approaches the bias torque T0. According to this structure, since the control to gradually approach the bias torque TMa and TMb of the electric generators 31a and 31b is performed in the MGECUs 33a and 33b, the processing burden of the EVECU 70 can be reduced compared with the control device 80 of the first embodiment.

[0127] <Other Implementation Methods>

[0128] Alternatively, each implementation method can also be implemented in the following ways.

[0129] • As a method for calculating the bias torque T0, instead of the above formula f2, the adjustment unit 702 can also calculate the bias torque T0 based on the difference between the acceleration AC of the vehicle 10 and the acceleration AS detected by the acceleration sensor 62 when the vehicle is parked.

[0130] Alternatively, when parking, the adjustment unit 702 can be adjusted, for example, by using... Figure 12 The mapping shown changes the specified value ΔT used in equation f5 above, based on the bias torque T0 and vehicle speed VC. Furthermore, since the bias torque T0 is related to the road surface slope θ, therefore, by using... Figure 12 The mapping shown causes the specified value ΔT to change, which can be based on the road surface slope θ.

[0131] The control device 80 of each embodiment can also be applied to vehicles with a so-called one-pedal structure, where the accelerator and brake can be operated by a single pedal. In such vehicles, the vehicle accelerates when the driver depresses the pedal and decelerates when the driver releases the pedal and returns it to its initial position. If the structure of the control device 80 of each embodiment is applied to such a vehicle, control can be performed to gradually bring the output torque of the electric generator closer to the bias torque when the driver releases the pedal and decelerates the vehicle. Therefore, the vehicle can be stopped more smoothly on inclined roads.

[0132] The control device 80 and control method described in this disclosure can also be implemented by one or more dedicated computers, which are provided by comprising a processor and a memory, the processor being programmed to perform one or more functions embodied in a computer program. Alternatively, the control device 80 and control method described in this disclosure can be implemented by a dedicated computer, which is provided by comprising a processor including one or more dedicated hardware logic circuits. Alternatively, the control device 80 and control method described in this disclosure can be implemented by one or more dedicated computers, which are composed of a processor and a memory programmed to perform one or more functions, and a processor including one or more hardware logic circuits. The computer program can also be stored in a computer-readable non-transitory tangible storage medium as instructions to be executed by a computer. The dedicated hardware logic circuits and hardware logic circuits can also be implemented by digital circuits or analog circuits including multiple logic circuits.

[0133] This disclosure is not limited to the specific examples described above. Even if those skilled in the art make appropriate design changes to the specific examples described above, as long as they include the features of this disclosure, they are included within the scope of this disclosure. The elements included in the above specific examples, as well as their configurations, conditions, shapes, etc., are not limited to the illustrated cases and can be appropriately modified. As long as no technical contradiction arises, the elements included in the above specific examples can be appropriately combined and changed.

Claims

1. A control device of a vehicle that includes a motor generator capable of applying a driving force and a braking force to a wheel of the vehicle, the braking force being applied to the wheel by causing the motor generator to regenerate when the vehicle is parked, the control device of the vehicle comprising: a motor control section that controls an output torque of the motor generator; and a bias torque calculation section that calculates a bias torque that needs to be applied to the wheel in order to park the vehicle on a road surface having a prescribed slope, the motor control section controlling the vehicle that is running so as to gradually approach the output torque of the motor generator to the bias torque when the vehicle is parked on the road surface having the prescribed slope, the motor control section executing the control to gradually approach the output torque of the motor generator to the bias torque while maintaining a deceleration constant.

2. The control device of a vehicle according to claim 1, characterized by Further comprising: a torque detection section that detects the output torque of the motor generator; and an acceleration detection section that detects an acceleration in a traveling direction of the vehicle, the bias torque calculation section calculating the bias torque based on the output torque of the motor generator detected by the torque detection section and the acceleration in the traveling direction of the vehicle detected by the acceleration detection section.

3. The control device of the vehicle according to claim 2, wherein the acceleration detection section is provided as a first acceleration detection section, and an acceleration detected by the first acceleration detection section is provided as a first acceleration, the control device of the vehicle further comprises a second acceleration detection section capable of detecting a component of a gravitational acceleration in a vehicle traveling direction, that is, a second acceleration, the bias torque calculation section calculates the bias torque based on the output torque of the motor generator detected by the torque detection section and the first acceleration detected by the first acceleration detection section when a speed in the traveling direction of the vehicle is a prescribed speed or more, the bias torque calculation section calculates the bias torque based on the second acceleration detected by the second acceleration detection section when the speed in the traveling direction of the vehicle is less than the prescribed speed. comprising:

4. The control device of a vehicle according to claim 1, characterized by a first acceleration detection section that detects an acceleration in a traveling direction of the vehicle, that is, a first acceleration; and a second acceleration detection section capable of detecting a component of a gravitational acceleration in a vehicle traveling direction, that is, a second acceleration, the bias torque calculation section calculates the bias torque based on a difference between the first acceleration and the second acceleration.

5. The control device of the vehicle according to claim 3, wherein the control device of the vehicle further comprises a rotation speed detection section that detects a rotation speed of the motor generator, the first acceleration detection section calculates the first acceleration based on the rotation speed of the motor generator detected by the rotation speed detection section.

6. The control device of the vehicle according to claim 4, wherein ​ ​ The control device of the vehicle further includes a rotation speed detection unit that detects a rotation speed of the motor generator, The first acceleration detection unit calculates a first acceleration based on the rotation speed of the motor generator detected by the rotation speed detection unit.

7. The control device of the vehicle according to any one of claims 1 to 6, characterized in that The bias torque calculation unit performs the calculation of the bias torque at a prescribed cycle, and performs a filter process based on a low-pass filter on the bias torque calculated at the prescribed cycle.

8. The control device of the vehicle according to any one of claims 1 to 6, characterized in that As the motor control unit, a first control unit and a second control unit are included, The first control unit sets a target value of an output torque of the motor generator, that is, a torque command value, The second control unit controls energization of the motor generator based on the torque command value, The second control unit controls so that the output torque of the motor generator gradually approaches the bias torque.

9. The control device of the vehicle according to any one of claims 1 to 6, characterized in that The motor control unit starts the control so that the output torque of the motor generator gradually approaches the bias torque based on a case where a speed of a traveling direction of the vehicle is less than a prescribed control start speed.

10. The control device of the vehicle according to any one of claims 1 to 6, characterized in that The control device of the vehicle further includes a brake control unit that controls a brake device that applies a brake force based on an oil pressure to the wheels, The motor control unit requests the brake control unit to apply the brake force to the wheels from the brake device after the output torque of the motor generator reaches the bias torque, and stops the motor generator.

Images