WO2023233903A1 - Moving body control device and program - Google Patents

Abstract

A control device (40) controls a moving body having a first braking/driving torque-applying part (30R) that applies a first braking/driving torque to a right drive wheel, a second braking/driving torque-applying part (30L) that applies a second braking/driving torque to a left driving wheel, and a right driven wheel and a left driven wheel composed of caster wheels. The control device includes a torque control unit (44) that controls the first braking/driving torque-applying part and the second braking/driving torque-applying part. The torque control unit performs turning, forward and reverse movement, and slip suppression for the moving body by controlling both the first braking/driving torque and the second braking/driving torque, or by controlling both the rotation speed of the right drive wheel and the rotation speed of the left drive wheel.

Description

Mobile control device, program Cross-reference of related applications

This application is based on Japanese Patent Application No. 2022-089039 filed on May 31, 2022, and claims the benefit of priority thereof, and all contents of the patent application are Incorporated herein by reference.

The present disclosure relates to a control device and a program for a mobile object.

Conventionally, there is a vehicle described in Patent Document 1 below. This vehicle includes a motor, disc brakes, and a steering device. The motor causes the vehicle to travel by applying torque to the wheels according to the amount of depression of the accelerator pedal by the driver. Disc brakes stop a vehicle by applying braking torque to the wheels based on the driver's depression of the brake pedal. A steering device turns a vehicle by steering wheels based on a driver's operation of a steering wheel.

Japanese Patent Application Publication No. 2006-341656

In a vehicle as described in Patent Document 1, in order to realize operations such as running, braking, turning, and suppressing slip of the vehicle, a power generation device such as a motor, a braking device such as a brake, and a steering device are required. . This is a factor that complicates the structure of the vehicle and reduces the robustness of the vehicle.

An object of the present disclosure is to provide a control device and program for a moving body that can simplify the structure and improve robustness.

A control device for a moving body according to an aspect of the present disclosure includes a first braking/driving torque applying section that applies a first braking/driving torque to a right driving wheel, and a second braking/driving torque applying section that applies a second braking/driving torque to a left driving wheel. This is a control device that controls a moving body that has a torque applying section and a right driven wheel and a left driven wheel that are formed of caster wheels. The control device includes a torque control section that controls a first braking/driving torque applying section and a second braking/driving torque applying section. The torque control unit controls the turning, front and back of the moving body by controlling the first braking/driving torque and the second braking/driving torque, or by controlling the rotation speed of the right drive wheel and the rotation speed of the left drive wheel, respectively. forward movement, and performs slip control.

Further, the program according to one aspect of the present disclosure includes a first braking/driving torque applying unit that applies a first braking/driving torque to the right driving wheel, and a second braking/driving torque applying unit that applies a second braking/driving torque to the left driving wheel. This is a program for controlling a moving body having a right driven wheel and a left driven wheel consisting of caster wheels. This program controls the turning of the moving object by controlling the first braking/driving torque and the second braking/driving torque, or by controlling the rotation speed of the right drive wheel and the left drive wheel, respectively. The CPU executes processing for speeding up and suppressing slippage.

According to these control devices and programs, the structure of the moving object can be simplified because it is possible to turn, move forward and backward, and suppress slipping of the moving object without using an electric power steering device or a braking device. At the same time, robustness can be ensured.

FIG. 1 is a diagram schematically showing a schematic configuration of a vehicle according to a first embodiment. FIG. 2 is a diagram schematically showing the side structure of the driven wheel of the first embodiment. FIG. 3 is a block diagram showing the electrical configuration of the vehicle of the first embodiment. FIG. 4 is a diagram schematically showing the configuration of the travel operation section of the first embodiment. FIG. 5 is a block diagram showing the configuration of the EVECU of the first embodiment. FIG. 6 is a flowchart showing the procedure of processing executed by the speed calculation section of the first embodiment. FIGS. 7A and 7B are diagrams showing an example of a map used by the speed difference calculating section of the first embodiment. FIG. 8 is a flowchart showing the procedure of processing executed by the slip control section of the first embodiment. FIG. 9 is a flowchart showing the procedure of processing executed by the torque distribution section of the first embodiment. FIGS. 10A and 10B are graphs showing an example of the torque applied to the left drive wheel and the right drive wheel of the first embodiment. FIG. 11 is a flowchart showing the procedure of processing executed by the torque distribution section of the second embodiment.

Hereinafter, one embodiment of a control device and a program for a moving body will be described with reference to the drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and redundant description will be omitted.
<First embodiment>
First, the schematic configuration of the vehicle of the first embodiment will be described. As shown in FIG. 1, the vehicle 10 of the present embodiment includes driven wheels 21R, 21L, driving wheels 22R, 22L, in- wheel motors 30R, 30L, and an EV (Electric Vehicle) ECU (Electronic Control Unit) 40. It is equipped with The vehicle 10 is a so-called slow mobility vehicle whose running speed is limited to a predetermined speed or less. The predetermined speed is set to "20 [km/h]", "50 [km/h]", etc. This vehicle 10 is not provided with a braking device or a steering device, and braking and turning of the vehicle 10 are realized by torque control of the in- wheel motors 30R and 30L. In this embodiment, the vehicle 10 corresponds to a moving body.

The driven wheels 21R and 21L are provided at the rear right and rear left of the vehicle 10, respectively. The driven wheels 21R and 21L are rotatable wheels, so-called caster wheels. The driven wheels 21R, 21L have fulcrums 210R, 210L fixed to the vehicle body 11, respectively, and are supported so as to be rotatable 360 degrees around the fulcrums 210R, 210L. That is, as shown in FIG. 2, if the axes passing through the centers of the fulcrums 210R and 210L and parallel to the vertical direction of the vehicle 10 are m10R and m10L, then the driven wheels 21R and 21L will move 360 degrees around the axes m10R and m10L. Each is rotatably supported. The driven wheels 21R and 21L rotate in the circumferential direction C around the axes m11R and m11L as the vehicle 10 travels. Below, the driven wheel 21R is also referred to as the "right driven wheel 21R", and the driven wheel 21L is also referred to as the "left driven wheel 21L".

As shown in FIG. 1, drive wheels 22R and 22L are provided at the front right and front left of the vehicle 10, respectively. Driving torque and braking torque are applied to the driving wheels 22R, 22L from in- wheel motors 30R, 30L. Hereinafter, the drive wheel 22R will also be referred to as the "right drive wheel 22R", and the drive wheel 22L will also be referred to as the "left drive wheel 22L". Further, the driving torque and the braking torque are also collectively referred to as "braking/driving torque." In this embodiment, the in-wheel motor 30R corresponds to a first braking/driving torque applying section, and the braking/driving torque applied from the in-wheel motor 30R to the right drive wheel 22R corresponds to the first braking/driving torque. Further, the in-wheel motor 30L corresponds to a second braking/driving torque applying section, and the braking/driving torque applied from the in-wheel motor 30L to the left drive wheel 22L corresponds to the second braking/driving torque.

The in- wheel motors 30R and 30L are built into the drive wheels 22R and 22L, respectively. As shown in FIG. 3, the in- wheel motors 30R, 30L include motor generators 31R, 31L, inverter devices 32R, 32L, MG (Motor Generator) ECUs 33R, 33L, and rotation sensors 34R, 34L, respectively. ing.

Inverter device 32R converts DC power supplied from a battery mounted on vehicle 10 into three-phase AC power, and supplies the converted three-phase AC power to motor generator 31R.
Motor generator 31R operates as an electric motor when vehicle 10 accelerates. When operating as an electric motor, motor generator 31R is driven based on three-phase AC power supplied from inverter device 32R. The drive torque of motor generator 31R is transmitted to right drive wheel 22R, thereby rotating right drive wheel 22R and accelerating vehicle 10.

The motor generator 31R shown in FIG. 3 operates as a generator when the vehicle 10 is braked. When operating as a generator, the motor generator 31R generates electricity through regenerative operation. Braking torque is applied to the right drive wheel 22R by the regenerative operation of the motor generator 31R. Three-phase AC power generated by motor generator 31R is converted to DC power by inverter device 32R, and the battery of vehicle 10 is charged.

Rotation sensor 34R detects the rotation speed of the output shaft of motor generator 31R, and outputs a signal corresponding to the detected rotation speed to MGECU 33R.
The MGECU 33R is mainly composed of a microcomputer including a CPU, memory, and the like. MGECU 33R controls motor generator 31R by executing a program stored in advance in its memory.

Specifically, MGECU 33R acquires information on the rotational speed of motor generator 31R based on the output signal of rotation sensor 34R. Furthermore, the MGECU 33R calculates the rotational speed of the right drive wheel 22R based on the rotational speed of the motor generator 31R using an arithmetic expression, a map, or the like. Furthermore, the MGECU 33R calculates the right drive wheel speed VR from the rotational speed of the right drive wheel 22R based on a predetermined calculation formula. The right drive wheel speed VR is the speed of the right drive wheel 22R in the traveling direction of the vehicle 10.

The MGECU 33R is communicably connected to the EVECU 40 via an in-vehicle network such as a CAN installed in the vehicle 10. The EVECU 40 sets a first target braking/driving torque TR*, which is a target value of the braking/driving torque of the right drive wheel 22R, and transmits the set first target braking/driving torque TR* to the MGECU 33R. The MGECU 33R monitors the rotational speed of the motor generator 31R and controls the motor generator 31R so that the actual torque output from the motor generator 31R becomes the first target braking/driving torque TR*. The first target braking/driving torque TR* is set to a positive value when accelerating the vehicle 10 in the forward direction D1 shown in FIG. 1, that is, when operating the motor generator 31R as an electric motor. Further, the first target braking/driving torque TR* is set to a negative value when decelerating the vehicle 10, that is, when causing the motor generator 31R to perform a regenerative operation.

The MGECU 33R transmits various information that can be acquired by the MGECU 33R, such as the right drive wheel speed VR, to the EVECU 40 in response to a request from the EVECU 40.
The motor generator 31L, inverter device 32L, MGECU 33L, and rotation sensor 34L of the in-wheel motor 30L operate similarly to each component of the in-wheel motor 30R. For example, the MGECU 33L monitors the rotational speed of the motor generator 31L and controls the motor generator 31L so that the actual torque output from the motor generator 31L becomes the second target braking/driving torque TL*. The second target braking/driving torque TL* is a target value of the braking/driving torque of the left drive wheel 22L, which is set by the EVECU 40. Furthermore, the MGECU 33L transmits various information that can be obtained by the MGECU 33L, such as the left drive wheel speed VL, to the EVECU 40 in response to a request from the EVECU 40.

As shown in FIG. 3, the vehicle 10 further includes a shift operation section 50 and a travel operation section 60 as operation sections for the driver to operate the vehicle 10.
In the shift operation section 50, it is possible to select, for example, a P (parking) range, an R (reverse) range, or a D (drive) range. The P range is selected when the vehicle 10 is stopped. The R range is selected when the vehicle 10 is driven in the backward direction D2 shown in FIG. The D range is selected when the vehicle 10 is driven in the forward direction D1 shown in FIG. Shift operation unit 50 outputs a signal indicating the selection state of P range, R range, and D range to EVECU 40.

The driving operation unit 60 shown in FIG. 4 is configured to accelerate, decelerate, and turn the vehicle 10 to the right when the R range or the D range is selected in the shift operation unit 50, that is, when moving the vehicle 10 forward or backward. , and the part operated when making a left turn. A joystick 61 is provided in the travel operation section 60. The joystick 61 can be operated from the neutral position shown in FIG. 4 in a forward direction J1, a backward direction J2, a rightward direction J3, a leftward direction J4, and directions intermediate therebetween. When the driver operates the joystick 61 from the neutral position in the forward direction J1, backward direction J2, rightward direction J3, and leftward direction J4, the vehicle 10 can be accelerated, decelerated, turned right, and turned left. Furthermore, when the driver operates the joystick 61 in an intermediate direction between the forward direction J1 and the rightward direction J3, the vehicle 10 can be accelerated and turned to the right. The operation amount S1 shown in FIG. 4 indicates the operation amount of the joystick 61 from the neutral position to the forward direction J1. The larger the operation amount S1 is, the larger the acceleration of the vehicle 10 can be. Similarly, the larger the operation amount S2 of the joystick 61 in the backward direction J2 from the neutral position, the larger the deceleration of the vehicle 10 becomes. Furthermore, the larger the operation amount S3, S4 of the joystick 61 from the neutral position to the right direction J3 or the left direction J4 becomes, the greater the turning speed of the vehicle 10 becomes. The travel operation section 60 outputs a signal indicating the operation state of the joystick 61 to the EVECU 40.

Hereinafter, the operation amount S1 of the joystick 61 from the neutral position to the forward direction J1 will be referred to as the "accelerator operation amount S1 of the travel operation section 60," and the operation amount S2 of the joystick 61 toward the rear direction J2 will be referred to as the "brake operation amount of the travel operation section 60." S2". Further, the operation amounts S3 and S4 in the right direction J3 and the left direction J4 are referred to as "the left and right direction operation amount S34 of the travel operation unit 60." The left-right direction operation amount S34 represents the operation amount S3 in the right direction J3 as a positive value, and represents the operation amount S4 in the left direction J4 as a negative value. In this embodiment, the accelerator operation amount S1 and the brake operation amount S2 of the travel operation unit 60 correspond to the first operation amount performed on the vehicle 10 in order to accelerate or decelerate the vehicle 10. Further, the left-right direction operation amount S34 of the travel operation unit 60 corresponds to a second operation amount performed on the vehicle 10 in order to turn the vehicle 10.

As shown in FIG. 3, the vehicle 10 further includes a yaw rate sensor 70 and an acceleration sensor 71.
The yaw rate sensor 70 detects the actual yaw rate Y, which is the yaw rate actually occurring in the vehicle body 11. As shown in FIG. 1, the actual yaw rate Y is the rotational speed around the vertical axis passing through the center of gravity Gc of the vehicle body 11. The actual yaw rate Y of this embodiment represents the rotation speed of the vehicle body 11 in the right direction D3 as a positive value, and represents the rotation speed of the vehicle body 11 in the left direction D4 as a negative value.

The acceleration sensor 71 detects the acceleration of the vehicle body 11. The acceleration sensor 71 is a so-called 6-axis acceleration sensor that can detect acceleration in the pitch direction, low direction, and yaw direction in addition to acceleration in the longitudinal direction, lateral direction, and vertical direction of the vehicle body 11. It is.

Each sensor 70, 71 outputs a signal corresponding to the detected physical quantity to the EVECU 40.
The EVECU 40 is mainly composed of a microcomputer including a CPU, memory, and the like. In this embodiment, the EVECU 40 corresponds to a control device and a computer. The EVECU 40 centrally controls the running of the vehicle 10 by executing a program stored in advance in its memory.

Specifically, the EVECU 40 receives output signals from the shift operation section 50, the travel operation section 60, the yaw rate sensor 70, and the acceleration sensor 71. The EVECU 40 acquires information on the operation state of the shift operation section 50 and the operation amounts S1, S2, and S34 of the drive operation section 60 based on the output signals of the shift operation section 50 and the travel operation section 60, respectively. Furthermore, the EVECU 40 acquires information such as the actual yaw rate Y and acceleration A of the vehicle body 11 based on the respective output signals of the yaw rate sensor 70 and the acceleration sensor 71. Further, the EVECU 40 acquires information on the right drive wheel speed VR and the left drive wheel speed VL from the MGECUs 33R and 33L of the in- wheel motors 30R and 30L, respectively.

The EVECU 40 sets the first target braking/driving torque TR* and the second target braking/driving torque TL* based on the acquired information. For example, when the driving operation unit 60 is operated in the forward direction J1 while the D range is selected in the shift operation unit 50, the EVECU 40 controls the first target braking/driving torque TR* and the second target braking/driving torque TL*. are set to the same positive value and transmitted to the in- wheel motors 30R and 30L, respectively. As a result, the same positive torque is applied from the in- wheel motors 30R, 30L to the drive wheels 22R, 22L, so that the vehicle 10 accelerates in the forward direction D1 shown in FIG. On the other hand, when the traveling operation unit 60 is operated in the backward direction J2, regenerative torque is applied from the in- wheel motors 30R, 30L to the drive wheels 22R, 22L, and the vehicle 10 is decelerated.

Furthermore, when the travel operation section 60 is operated in the right direction J3 while the D range is selected in the shift operation section 50, the EVECU 40 controls the first target braking/driving torque TR* and the second target braking/driving torque TL*. and cause a deviation. Specifically, the EVECU 40 sets the second target braking/driving torque TL* to be larger than the first target braking/driving torque TR*, and transmits them to the in- wheel motors 30R and 30L, respectively. As a result, the torque applied from the in-wheel motor 30L to the left drive wheel 22L is greater than the torque applied from the in-wheel motor 30R to the right drive wheel 22R, so that the vehicle 10 is Turn in direction D3. On the other hand, when the traveling operation unit 60 is operated in the left direction J4, the EVECU 40 applies a torque applied from the in-wheel motor 30R to the right drive wheel 22R, rather than a torque applied from the in-wheel motor 30L to the left drive wheel 22L. By increasing , the vehicle 10 is caused to turn in the left direction D4 shown in FIG.

Next, with reference to FIG. 5, a method of controlling the vehicle 10 executed by the EVECU 40 will be described in detail.
As shown in FIG. 5, the EVECU 40 has a basic braking/driving torque setting section 41, a speed calculation section 42, and a torque deviation setting section as functional configurations realized by executing a program stored in its memory. section 43 and a torque control section 44.

The basic braking/driving torque setting section 41 includes a braking/driving torque calculating section 410 , a speed upper limit calculating section 411 , and a selecting section 412 .
The braking/driving torque calculating section 410 calculates a first basic braking/driving torque based on the operating state of the shift operating section 50, the operating amounts S1, S2, S34 of the travel operating section 60, and the vehicle speed Vb calculated by the speed calculating section 42. Set Ta. The vehicle speed Vb is an estimated value of the speed of the vehicle body 11 in the traveling direction. The first basic braking/driving torque Ta is a reference value of the braking/driving torque to be applied to the right drive wheel 22R and the left drive wheel 22L, respectively, in order to accelerate or decelerate the vehicle 10.

For example, when the travel operation section 60 is operated in the forward direction J1 while the D range is selected in the shift operation section 50, the braking/driving torque calculation section 410 calculates the accelerator operation which is the operation amount of the travel operation section 60. A first basic braking/driving torque Ta is calculated from the amount S1 and the vehicle speed Vb based on a map, a calculation formula, etc. In this case, the first basic braking/driving torque Ta is set to a positive value. Furthermore, when the travel operation section 60 is operated in the backward direction J2 while the D range is selected in the shift operation section 50, the braking/driving torque calculation section 410 calculates the amount of brake operation that is the operation amount of the travel operation section 60. A first basic braking/driving torque Ta is calculated from the amount S2 and the vehicle speed Vb based on a map, a calculation formula, etc. In this case, the first basic braking/driving torque Ta is set to a negative value.

Note that even when the R range is selected in the shift operation section 50, the braking/driving torque calculation section 410 similarly calculates the first basic braking/driving torque based on the accelerator operation amount S1 and the brake operation amount S2 of the travel operation section 60. Set Ta. However, in this case, when the travel operation unit 60 is operated in the forward direction J1, the first basic braking/driving torque Ta is set to a negative value, and when the travel operation unit 60 is operated in the rear direction J2, the first basic braking/driving torque Ta is set to a negative value. The first basic braking/driving torque Ta is set to a positive value.

The speed upper limit calculation section 411 sets the second basic braking/driving torque Tb based on the vehicle speed Vb calculated by the speed calculation section 42 and the left/right direction operation amount S34 of the travel operation section 60. The second basic braking/driving torque Tb is the upper limit value of the braking/driving torque to be applied to the right drive wheel 22R and the left drive wheel 22L, respectively, in order to limit the traveling speed of the vehicle body 11 to a preset upper limit speed or less. . For example, the speed upper limit calculating section 411 calculates the upper limit speed Vmax, which is the upper limit value of the traveling speed of the vehicle body 11, from the left and right direction operation amount S34 of the traveling operation section 60 from a map. In this map, the upper limit speed Vmax is set to become smaller as the absolute value of the left-right operation amount S34 of the travel operation unit 60 becomes larger. The speed upper limit calculation unit 411 sets the second basic braking/driving torque Tb by feedback control based on the deviation between the current vehicle speed Vb and the upper limit speed Vmax.

The first basic braking/driving torque Ta and the second basic braking/driving torque Tb calculated by the braking/driving torque calculation unit 410 and the speed upper limit calculation unit 411 are input to the selection unit 412. The selection unit 412 sets the smaller of the first basic braking/driving torque Ta and the second basic braking/driving torque Tb as the third basic braking/driving torque Tc. The third basic braking/driving torque Tc set by the selection section 412 is input to the torque control section 44. The third basic braking/driving torque Tc is a target value of the braking/driving torque to be applied to the right drive wheel 22R and the left drive wheel 22L, respectively, in order to accelerate or decelerate the vehicle 10.

The speed calculation unit 42 acquires information on the right drive wheel speed VR from the in-wheel motor 30R, and also acquires information on the left drive wheel speed VL from the in-wheel motor 30L. Further, the speed calculation unit 42 acquires information on the acceleration A of the vehicle body 11 in the traveling direction based on the output signal of the acceleration sensor 71. The speed calculation unit 42 estimates a vehicle speed Vb, which is the speed of the vehicle body 11, based on the right drive wheel speed VR, the left drive wheel speed VL, and the acceleration A of the vehicle body 11.

Specifically, the speed calculation unit 42 calculates the vehicle speed Vb by executing the process shown in FIG. Note that the speed calculation unit 42 repeatedly executes the process shown in FIG. 6 at a predetermined cycle while the vehicle 10 is started.
As shown in FIG. 6, the speed calculation unit 42 first calculates the vehicle speed VG from the acceleration A of the vehicle body 11 based on the following equation f1 as processing in step S10.

VG=VG _n-1 +∫A (f1)
In formula f1, VG _n-1 is the previous estimated value of the vehicle speed calculated by formula f1.
The speed calculation unit 42 determines whether the first basic braking/driving torque Ta satisfies "Ta>0" as processing in step S11 following step S10. If the first basic braking/driving torque Ta satisfies "Ta>0", the speed calculation unit 42 makes an affirmative determination in the process of step S11. In this case, the speed calculating unit 42 determines that the vehicle 10 is in an accelerating state, and calculates the final estimated value Vb of the vehicle body speed using the following equation f2 as the process of step S12.

Vb=MIN(VL, VR, VG) (f2)
For example, when both the right drive wheel 22R and the left drive wheel 22L are not slipping, the right drive wheel speed VR, the left drive wheel speed VL, and the calculated value VG of the vehicle body speed are approximately the same value. Therefore, the final vehicle speed estimate Vb is set to any one of the right drive wheel speed VR, the left drive wheel speed VL, and the calculated vehicle speed VG.

Furthermore, when the right drive wheel 22R slips, the right drive wheel speed VR calculated based on the rotational speed of the right drive wheel 22R increases. In this case, the final estimated value Vb of the vehicle speed is set to either the left driving wheel speed VL or the calculated vehicle speed VG. Similarly, when the left driving wheel 22L slips, the final estimated value Vb of the vehicle speed is set to either the right driving wheel speed VR or the calculated value VG of the vehicle speed. Further, when both the right drive wheel 22R and the left drive wheel 22L slip, both the right drive wheel speed VR and the left drive wheel speed VL increase. In this case, the final estimated value Vb of the vehicle speed is set to the calculated value VG of the vehicle speed.

In this way, by setting the final estimated value Vb of the vehicle body speed using the above formula f2, it is possible to estimate the vehicle body speed Vb while excluding the speed of the driving wheel that has slipped, so that a more appropriate vehicle body speed can be determined. It is possible to calculate the speed Vb.
If the first basic braking/driving torque Ta does not satisfy "Ta>0" in the process of step S11, the speed calculation unit 42 makes a negative determination in the process of step S11. In this case, the speed calculation unit 42 determines that the vehicle 10 is decelerating, and calculates the final estimated value Vb of the vehicle body speed using the following equation f3 as the process of step S13.

Vb=MAX(VL, VR, VG) (f3)
By the way, the calculated value VG of the vehicle speed calculated by the above f1 includes an integral error. Therefore, when using the calculated value VG of the vehicle speed as the final estimated value Vb of the vehicle speed in the above formulas f2 and f3, there is a possibility that the calculation accuracy of the final estimated value Vb of the vehicle speed will decrease. be. Therefore, the speed calculation unit 42 eliminates the integration error of the calculated value VG of the vehicle body speed by using the right drive wheel speed VR and the left drive wheel speed VL, which have high estimation accuracy.

Specifically, after executing the process of step S12 or the process of step S13, the speed calculation unit 42 performs the process of step S14 such that the final estimated value Vb of the vehicle speed is the right drive wheel speed VR and the left drive wheel speed VR. It is determined whether the speed matches any of the speeds VL or not. If the final vehicle speed estimate Vb matches the right drive wheel speed VR, the speed calculation unit 42 makes an affirmative determination in step S14, and performs the following steps in step S15. The calculated value VG of the vehicle body speed is set as the right drive wheel speed VR. Similarly, when the final estimated value Vb of the vehicle speed matches the left driving wheel speed VL, the speed calculation unit 42 sets the calculated value VG of the vehicle speed to the left driving wheel speed VL. As a result, even if the calculated value VG of the vehicle body speed includes an integral error, the vehicle body speed The integral error of the calculated value VG is eliminated. Note that in the process of step S14, the speed calculation unit 42 performs the process of step S14 when the final estimated value Vb of the vehicle speed does not match either the right drive wheel speed VR or the left drive wheel speed VL. A negative determination is made in step 2, and the processing shown in FIG. 6 is ended.

As shown in FIG. 5, the vehicle speed Vb calculated by the speed calculation section 42 is input to the basic braking/driving torque setting section 41 and the torque deviation setting section 43.
The torque deviation setting section 43 includes a speed difference calculation section 430, a subtraction section 431, an addition section 432, a first feedback control section 433, and a second feedback control section 434.

The speed difference calculation unit 430 calculates the target speed difference ΔV* based on the vehicle speed Vb, the actual yaw rate Y of the vehicle body 11 calculated based on the output signal of the yaw rate sensor 70, and the left-right direction operation amount S34 of the travel operation unit 60. Set. The target speed difference ΔV* is a target value of the speed difference that should be generated between the right drive wheel speed VR and the left drive wheel speed VL in order to cause the vehicle 10 to turn.

For example, the speed difference calculation unit 430 sets the basic speed difference ΔVb from the vehicle speed Vb and the left-right direction operation amount S34 of the travel operation unit 60 using a map shown in FIG. 7(A) or the like. The basic speed difference ΔVb is a reference value for the target speed difference ΔV*. Further, the speed difference calculation unit 430 sets the target yaw rate Y* from the vehicle speed Vb and the left-right operation amount S34 of the travel operation unit 60 using a map shown in FIG. 7(B) or the like. Target yaw rate Y* is a target value of the yaw rate of the vehicle body 11. The speed difference calculation unit 430 calculates a speed difference correction value ΔVc based on a calculation formula etc. from the deviation between the actual yaw rate Y and the target yaw rate Y* of the vehicle 10, and also calculates the basic speed difference correction value ΔVc based on the calculated speed difference correction value ΔVc. A target speed difference ΔV* is calculated by correcting the speed difference ΔVb. Note that the speed difference calculation unit 430 uses the target speed difference ΔV* as is when the shift operation unit 50 is set to the D range, but uses the target speed difference ΔV* as is when the shift operation unit 50 is set to the R range. The positive and negative signs of the speed difference ΔV* are set to be reversed.

As shown in FIG. 5, the target speed difference ΔV* set by the speed difference calculating section 430 is input to the subtracting section 431 and the adding section 432. The subtraction unit 431 obtains the target right drive wheel speed VR* by subtracting the target speed difference ΔV* from the vehicle speed Vb calculated by the speed calculation unit 42. The adding unit 432 adds the target speed difference ΔV* to the vehicle speed Vb calculated by the speed calculating unit 42 to obtain the target left driving wheel speed VL*.

Based on the target right drive wheel speed VR* calculated by the subtraction unit 431, the first feedback control unit 433 performs feedback control based on the deviation between the actual right drive wheel speed VR and the target right drive wheel speed VR*. Calculate driving wheel correction torque ΔTcR. The right driving wheel correction torque ΔTcR calculated by the first feedback control section 433 is input to the torque control section 44 .

Based on the target left drive wheel speed VL* calculated by the addition unit 432, the second feedback control unit 434 performs feedback control on the left drive wheel based on the deviation between the actual left drive wheel speed VL and the target left drive wheel speed VL*. Calculate driving wheel correction torque ΔTcL. The left driving wheel correction torque ΔTcL calculated by the second feedback control section 434 is input to the torque control section 44.

The torque control section 44 includes a torque distribution section 440, a first slip control section 441, and a second slip control section 442.
The torque distribution unit 440 generates a third basic braking/driving torque Tc calculated by the selection unit 412, a right driving wheel correction torque ΔTcR calculated by the first feedback control unit 433, and a left driving wheel correction torque ΔTcR calculated by the second feedback control unit 434. A first target braking/driving torque TR* and a second target braking/driving torque TL* are calculated from the drive wheel correction torque ΔTcL. Specifically, the torque distribution unit 440 calculates the first target braking/driving torque TR* (=Tc+ΔTcR) by adding the right driving wheel correction torque ΔTcR to the third basic braking/driving torque Tc. Similarly, the torque distribution unit 440 obtains the second target braking/driving torque TL* (=Tc+ΔTcL) by adding the left driving wheel correction torque ΔTcL to the third basic braking/driving torque Tc. The first target braking/driving torque TR* and the second target braking/driving torque TL* calculated by the torque distribution section 440 are input to the first slip control section 441 and the second slip control section 442, respectively. In this embodiment, the corrected torques ΔTcR and ΔTcL correspond to the torque deviation.

The first slip control unit 441 determines whether or not the situation is such that the slip of the right drive wheel 22R should be suppressed, and if it is determined that the situation is not such that the slip of the right drive wheel 22R should be suppressed, The first target braking/driving torque TR* output from the distribution unit 440 is output as is to the in-wheel motor 30R. On the other hand, when the first slip control unit 441 determines that the situation is such that the slip of the right drive wheel 22R should be suppressed, the first slip control unit 441 limits the absolute value of the first target braking/driving torque TR* to below the first slip torque TsR. The first slip suppression control is executed. The first slip torque TsR is a braking/driving torque that should be applied to the right drive wheel 22R in order to make the slip rate of the right drive wheel 22R a predetermined target slip rate.

The second slip control unit 442 performs the same control on the left drive wheel 22L as the first slip control unit 441 performs on the right drive wheel 22R. That is, when the second slip control unit 442 determines that the situation is such that the slip of the left drive wheel 22L should be suppressed, the second slip control unit 442 limits the absolute value of the second target braking/driving torque TL* to the second slip torque TsL or less. Execute second slip suppression control.

Note that the first slip control unit 441 and the second slip control unit 442 share a slip control flag Xslip that indicates whether slip suppression control is being executed. The first slip control unit 441 and the second slip control unit 442 set the slip control flag Xslip to “1” when at least one of the first slip suppression control and the second slip suppression control is being executed. Further, the first slip control section 441 and the second slip control section 442 set the slip control flag Xslip to "0" when both the first slip suppression control and the second slip suppression control are not executed.

Next, the procedure of the process executed by the first slip control section 441 and the second slip control section 442 will be specifically explained. Note that since the processes executed by the first slip control section 441 and the second slip control section 442 are the same, the procedure of the first slip control section 441 will be described below as a representative.

The first slip control unit 441 executes the process shown in FIG. Note that the first slip control unit 441 repeatedly executes the process shown in FIG. 8 at a predetermined cycle while the vehicle 10 is running.
As shown in FIG. 8, the first slip control unit 441 calculates the deviation |VR−Vb| between the right drive wheel speed VR and the vehicle body speed Vb, and also calculates the calculated deviation |VR It is determined whether -Vb| satisfies "|VR-Vb|≧Vth10". The predetermined value Vth10 is a determination value for determining whether the situation is such that the slip of the right drive wheel 22R should be suppressed, and is set to, for example, "3 [km/h]". If the deviation |VR-Vb| satisfies "|VR-Vb|≧Vth10", the first slip control unit 441 makes an affirmative determination in the process of step S20. In this case, the first slip control unit 441 determines that the situation is such that the slip of the right drive wheel 22R should be suppressed.

If the first slip control unit 441 makes a positive determination in the process of step S20, it executes the first slip suppression control as the process of the subsequent step S21. That is, the first slip control unit 441 limits the absolute value of the first target braking/driving torque TR* to be equal to or less than the first slip torque TsR. The first slip control unit 441 sets the slip control flag Xslip to "1" as processing in step S22 following step S21.

The first slip control unit 441 determines whether the first basic braking/driving torque Ta satisfies "Ta>0" as a process in step S23 following step S22. If the first basic braking/driving torque Ta satisfies "Ta>0", the first slip control unit 441 makes an affirmative determination in the process of step S23. In this case, the first slip control unit 441 determines that the vehicle 10 is in an accelerating state, and calculates a target slip speed Vcmd from the vehicle body speed Vb based on the following formula f4 as processing in step S24. .

Vcmd=(1+α)×Vb (f4)
In formula f4, the predetermined value α is set in advance based on the target slip ratio of the right drive wheel 22R. For example, when the target slip rate when the right drive wheel 22R slips is set to 3%, the predetermined value α is set to "0.03".

If the first basic braking/driving torque Ta does not satisfy "Ta>0" in the process of step S23, the first slip control unit 441 makes a negative determination in the process of step S23. In this case, the first slip control unit 441 determines that the vehicle 10 is decelerating, and calculates the target slip speed Vcmd based on the following equation f5 as the process of step S25.

Vcmd=(1-α)×Vb (f5)
After performing the process of step S23 or the process of step S24, the first slip control unit 441 calculates the first slip torque TsR as a process of subsequent step S26. Specifically, the first slip control unit 441 controls the first slip torque TsR by PI feedback control based on the deviation between the target slip speed Vcmd calculated in the process of step S23 or the process of step S24 and the right drive wheel speed VR. Calculate. That is, the first slip control unit 441 calculates the speed deviation eV from the target slip speed Vcmd and the right drive wheel speed VR based on the following equation f6.

eV=Vcmd-VR (f6)
Next, the first slip control unit 441 calculates the first slip torque TsR from the calculated speed deviation eV based on the following equation f7.
TsR=Kp×eV+Ki×∫eV (f7)
In formula f7, "Kp" and "Ki" are predetermined proportional gains and integral gains that are set in advance.

Note that the first slip control unit 441 limits the first slip torque TsR to a range from a lower limit value Tmin to an upper limit value Tmax based on the following equation f8.
Tmin<TsR<Tmax (f8)
The lower limit value Tmin and the upper limit value Tmax are set in advance. As the lower limit Tmin, for example, the maximum braking torque that can be output from the motor generator 31R of the in-wheel motor 30R is used. As the upper limit Tmax, for example, the maximum drive torque that can be output from the motor generator 31R of the in-wheel motor 30R is used.

The first slip control unit 441 determines whether the first basic braking/driving torque Ta is greater than or equal to the first slip torque TsR as processing in step S27 following step S26. If the first basic braking/driving torque Ta is greater than or equal to the first slip torque TsR, the first slip control unit 441 makes an affirmative determination in the process of step S27, and adjusts the right drive wheel speed VR as the process of step S28. The deviation |VR-Vb| between the vehicle speed Vb and the vehicle speed Vb is calculated, and it is determined whether the condition that "|VR-Vb|≦Vth11" continues for a predetermined period of time. The predetermined value Vth11 is a determination value for determining whether the slip state of the right drive wheel 22R has converged, and is set to, for example, "0 [km/h]". Note that the predetermined value Vth11 and the predetermined value Vth10 used in the process of step S20 may be the same value. The predetermined time is set to "1 [sec]", for example.

If the first slip control unit 441 makes a negative determination in the process of step S28, it determines that the slip state of the right drive wheel 22R has not converged, and temporarily ends the process shown in FIG. do. In this case, the first slip suppression control is continued.
By continuing the first slip suppression control, when the deviation |VR-Vb| between the right drive wheel speed VR and the vehicle body speed Vb becomes smaller, the deviation |VR-Vb| becomes "|VR-Vb|<Vth10". Become satisfied. In this case, the first slip control unit 441 makes a negative determination in the process of step S20, and determines whether the slip control flag Xslip is set to "0" in the subsequent process of step S29. Since the slip control flag Xslip is set to "1" at this stage, the first slip control unit 441 makes a negative determination in the process of step S29 and executes the processes from step S23 onwards.

Thereafter, the first slip suppression control is further continued, and the state in which the deviation |VR-Vb| between the right drive wheel speed VR and the vehicle body speed Vb satisfies "|VR-Vb|≦Vth11" continues for a predetermined time. Then, the first slip control unit 441 makes an affirmative determination in step S28. In this case, the first slip control unit 441 determines that the slip state of the right drive wheel 22R has converged, and after completing the first slip suppression control as the process in step S30, sets the slip control flag Xslip as the process in step S31. Set to "0".

Note that in the process of step S31, the first slip control unit 441 maintains the slip control flag Xslip at “1” when the second slip control unit 442 is executing the second slip suppression control. On the other hand, the first slip control section 441 maintains the slip control flag Xslip at "0" when the second slip control section 442 is not executing the second slip suppression control. As a result, the slip control flag Xslip is set to "1" when either the first slip suppression control or the second slip suppression control is executed, and when both of them are not executed It will be set to "0".

The first slip control unit 441 continuously executes the first slip suppression control for a period after starting the first slip suppression control in the process of step S21 until ending the first slip suppression control in the process of step S30. do.
Even if the slip state of the right drive wheel 22R has not converged, the first slip control unit 441 controls the first basic braking/driving torque Ta if a negative determination is made in the process of step S27. If the torque becomes less than the first slip torque TsR, the first slip suppression control is finished as the process in step S30, and then the process in step S31 is executed. If the first basic braking/driving torque Ta becomes less than the first slip torque TsR, even if the first target braking/driving torque TR* is set based on the first basic braking/driving torque Ta, the braking/driving that causes slip will occur. No torque is applied to the right drive wheel 22R. Therefore, when the first basic braking/driving torque Ta becomes less than the first slip torque TsR, the first slip control section 441 ends the first slip suppression control.

When the slip control flag Xslip is set to "0" through the process in step S31, when the first slip control section 441 subsequently executes the process shown in FIG. Make a positive judgment in processing. In this case, the first slip control unit 441 determines whether the first basic braking/driving torque Ta satisfies "Ta>0" as the process of step S32. If the first basic braking/driving torque Ta satisfies "Ta>0", the first slip control unit 441 makes an affirmative determination in the process of step S32. In this case, the first slip control unit 441 determines that the vehicle 10 is in an accelerating state, and sets the first slip torque TsR to the upper limit value Tmax as processing in step S33. On the other hand, if the first basic braking/driving torque Ta does not satisfy "Ta>0", the first slip control unit 441 makes a negative determination in the process of step S32. In this case, the first slip control unit 441 determines that the vehicle 10 is decelerating, and sets the first slip torque TsR to the lower limit value Tmin in step S34. The process in step S33 and the process in step S34 are performed to avoid using the first slip torque TsR for calculating the first target braking/driving torque TR* when the first slip suppression control is not being executed. . After the first slip control unit 441 executes the process of step S33 or the process of step S34, it ends the process shown in FIG.

As described above, the second slip control unit 442 shown in FIG. 5 executes the same process as the process shown in FIG. 8 on the left drive wheel 22L. In this embodiment, the slip suppression control for the right drive wheel 22R and the slip suppression control for the left drive wheel 22L are independently executed by the first slip control section 441 and the second slip control section 442, respectively.

By the way, when the braking/driving torque is limited by executing slip suppression control on either the right drive wheel 22R or the left drive wheel 22L, the vehicle 10 must be limited in the braking/driving torque for the other drive wheel as well. It is not possible to maintain the running condition of the vehicle properly. For example, in a situation where the right drive wheel 22R is in contact with a low-μ road, which is a road surface with a low road surface friction coefficient, and the left drive wheel 22L is in contact with a high-μ road, which is a road surface with a high road surface friction coefficient. When the right drive wheel 22R slips, if only the drive torque of the right drive wheel 22R is limited, the drive torque of the right drive wheel 22R becomes smaller than the drive torque of the left drive wheel 22L, so the vehicle 10 may unintentionally slide to the right. The vehicle will turn in direction D3. In order to avoid this, when the drive torque of the right drive wheel 22R is limited by the slip suppression control, it is necessary to similarly limit the drive torque of the left drive wheel 22L. In other words, it is necessary to limit the braking/driving torque of the driving wheels that are in contact with the high μ road based on the braking/driving torque of the driving wheels that are in contact with the low μ road. In addition, in order to further turn the vehicle 10 in such a situation, while maintaining the state in which the drive torque of both the drive wheels 22R and 22L is limited, the braking/driving torque of each of the drive wheels 22R and 22L is changed. It is necessary to create a deviation.

The torque distribution unit 440 executes the process shown in FIG. 9 as a process to realize the braking/driving torque for each of the drive wheels 22R, 22L as described above. Note that the torque distribution unit 440 repeatedly executes the process shown in FIG. 9 at a predetermined cycle while the vehicle 10 is running.

As shown in FIG. 9, the torque distribution unit 440 first determines whether the first basic braking/driving torque Ta satisfies "Ta>0" as the process of step S40. If the first basic braking/driving torque Ta satisfies "Ta>0", the torque distribution unit 440 makes an affirmative determination in the process of step S40. In this case, the torque distribution unit 440 determines that the vehicle 10 is in an accelerating state, and as a process of step S41, the third basic braking/driving torque Tc and the first slip torque TsR calculated by the selection unit 412 are , and the second slip torque TsL, the fourth basic braking/driving torque Td is calculated based on the following equation f9.

Td=MIN(Tc, TsR, TsL) (f9)
That is, the torque distribution unit 440 sets the smallest one among the third basic braking/driving torque Tc, the first slip torque TsR, and the second slip torque TsL as the fourth basic braking/driving torque Td.

In step S42 following step S41, the torque distribution unit 440 determines whether the slip control flag Xslip is set to "0". When the slip control flag Xslip is set to "0", that is, when both the first slip suppression control and the second slip suppression control are not executed, the torque distribution unit 440 determines that the result is positive in the process of step S42. make judgments. In this case, the torque distribution unit 440 sets the first target braking/driving torque TR* and the second target braking/driving torque TL* based on the following equations f10 and f11 as the process of step S51.

TR*=Td+ΔTcR (f10)
TL*=Td+ΔTcL (f11)
When both the first slip suppression control and the second slip suppression control are not executed, the first slip torque TsR and the second slip torque TsL are set to the upper limit value Tmax by the process of step S33 shown in FIG. Therefore, in the process of step S41, the fourth basic braking/driving torque Td is set to the third basic braking/driving torque Tc. As a result, in the process of step S51, the first target braking/driving torque TR* is set to "Tc+ΔTcR", and the second target braking/driving torque TL* is set to "Tc+ΔTcL". That is, the torque distribution unit 440 sets the target braking/driving torques TR*, TL* using the normal setting procedure described above.

On the other hand, when the slip control flag Make a negative judgment in the process. In this case, the torque distribution unit 440 determines whether the fourth basic braking/driving torque Td matches the second slip torque TsL as processing in step S43.

For example, when the second slip suppression control is executed for the left drive wheel 22L, the second slip torque TsL has a value smaller than the third basic braking/driving torque Tc and the first slip torque TsR. Therefore, in the process of step S41, the fourth basic braking/driving torque Td is set to the second slip torque TsL. As a result, the torque distribution unit 440 makes a positive determination in the process of step S43. In this case, the torque distribution unit 440 determines that the second slip suppression control is being executed for the left drive wheel 22L, and performs the second slip suppression control based on the following equations f12 and f13 as the process of step S44. A first target braking/driving torque TR* and a second target braking/driving torque TL* are set.

TR*=Td-|ΔTcR|-|ΔTcL| (f12)
TL*=TsL (f13)
In this manner, when the second slip suppression control is performed on the left drive wheel 22L, the second target braking/driving torque TL* of the left drive wheel 22L is limited to the second slip torque TsL. On the other hand, the first target braking/driving torque TR* of the non-slip right driving wheel 22R is calculated from the fourth basic braking/driving torque Td by the absolute value of the right driving wheel correction torque |ΔTcR| and the absolute value of the left driving wheel correction torque | It is set to a value obtained by subtracting TcL|. Considering that the fourth basic braking/driving torque Td is set to the second slip torque TsL, the first target braking/driving torque TR* of the right drive wheel 22R is also limited to the second slip torque TsL or less. .

On the other hand, when the first slip suppression control is executed for the right drive wheel 22R, the first slip torque TsR has a value smaller than the third basic braking/driving torque Tc and the second slip torque TsL. Therefore, in the process of step S41, the fourth basic braking/driving torque Td is set to the first slip torque TsR. As a result, the torque distribution unit 440 makes a negative determination in the process of step S43. In this case, the torque distribution unit 440 determines that the first slip suppression control is being executed for the right drive wheel 22R, and performs the first slip suppression control based on the following equations f14 and f15 as the process of step S45. A first target braking/driving torque TR* and a second target braking/driving torque TL* are set.

TR*=TsR (f14)
TL*=Td-|ΔTcR|-|ΔTcL| (f15)
On the other hand, if the first basic braking/driving torque Ta does not satisfy "Ta>0" in the process of step S40, the torque distribution unit 440 makes a negative determination in the process of step S40. In this case, the torque distribution unit 440 determines that the vehicle 10 is decelerating, and executes the processes of steps S46 to S51. Note that the processing in steps S46 to S50 is a modification of the processing in steps S41 to S45 to correspond to the deceleration of the vehicle 10, and is the same or similar to the processing in steps S41 to S45, A detailed explanation will be omitted.

Next, an example of the operation of this embodiment will be described.
When the drive operation unit 60 is operated to an intermediate position between the forward direction D1 and the right direction D3 in a situation where neither of the drive wheels 22R and 22L of the vehicle 10 is slipping, the right drive wheel 22R and the left drive wheel 22L are driven respectively. The torque is set, for example, as shown in FIG. 10(A). First, the third basic braking/driving torque Tc is set based on the accelerator operation amount S1 which is the operating amount in the forward direction D1 of the traveling operation unit 60, and the third basic braking/driving torque Tc is set as the fourth basic braking/driving torque Td. is used as is. Furthermore, the right driving wheel correction torque ΔTcR and the left driving wheel correction torque ΔTcL are set based on the left and right direction operation amount S34 of the travel operation unit 60. In this case, the right driving wheel correction torque ΔTcR is set to a negative value, while the left driving wheel correction torque ΔTcL is set to a positive value. Therefore, the in-wheel motor 30R applies a torque obtained by adding the right driving wheel correction torque ΔTcR to the third basic braking/driving torque Tc to the right driving wheel 22R, as shown in FIG. 10(A). Further, the in-wheel motor 30L applies a torque obtained by adding the left drive wheel correction torque ΔTcL to the third basic braking/driving torque Tc to the left drive wheel 22L. As a result, the torque applied to the left drive wheel 22L becomes smaller than the torque applied to the right drive wheel 22R, so the vehicle 10 turns in the right direction D3.

On the other hand, if the left drive wheel 22L of the vehicle 10 slips in a situation where the travel operation unit 60 is operated to an intermediate position between the forward direction D1 and the right direction D3, the drive torque of each of the right drive wheel 22R and the left drive wheel 22L is set, for example, as shown in FIG. 10(B). First, the third basic braking/driving torque Tc is set based on the accelerator operation amount S1, which is the operation amount of the driving operation section 60 in the forward direction D1. Furthermore, since the left drive wheel 22L is slipping, a second slip torque TsL that can suppress the slip of the left drive wheel 22L is set. In this case, if the second slip torque TsL is smaller than the third basic braking/driving torque Tc, the fourth basic braking/driving torque Td is set to the second slip torque TsL. Furthermore, the right driving wheel correction torque ΔTcR and the left driving wheel correction torque ΔTcL are set based on the left and right direction operation amount S34 of the travel operation unit 60. In this case, the right driving wheel correction torque ΔTcR is set to a negative value, while the left driving wheel correction torque ΔTcL is set to a positive value. As a result of the above, the in-wheel motor 30L applies the second slip torque TsL to the left drive wheel 22L, as shown in FIG. 10(B). Further, the in-wheel motor 30R applies a torque “TsL−|ΔTcR|−|ΔTcL|” obtained by subtracting “|ΔTcR|+|ΔTcL|” from the second slip torque TsL to the right drive wheel 22R. As a result, the vehicle 10 turns in the right direction D3 while the slip of the left drive wheel 22L is suppressed.

According to the EVECU 40 of the present embodiment described above, the functions and effects shown in (1) to (6) below can be obtained.
(1) The EVECU 40 includes a torque control section 44 that controls the in-wheel motor 30R and the in-wheel motor 30L. The torque control unit 44 controls the braking/driving torques applied from the in- wheel motors 30R, 30L to the right drive wheel 22R and left drive wheel 22L, respectively, thereby controlling turning, forward/backward movement, and slippage of the vehicle 10. According to this configuration, turning, forward/backward movement, and slip suppression of the vehicle 10 can be realized without using an electric power steering device or a braking device, so that the structure of the vehicle 10 can be simplified and robustness can be ensured. be able to.

(2) The torque control unit 44 generates a first slip torque TsR, which is a braking/driving torque to be applied to the right drive wheel 22R in order to make the slip rate of the right drive wheel 22R a predetermined target slip rate, and the left drive wheel 22L. A second slip torque TsL, which is a braking/driving torque to be applied to the left driving wheel 22L, is calculated in order to make the slip ratio of the left drive wheel 22L a predetermined target slip ratio. When the right drive wheel 22R is in contact with a road surface having a lower coefficient of road friction than the left drive wheel 22L, the torque control unit 44 performs control based on the first slip torque TsR to suppress the slip of the right drive wheel 22R. First slip suppression control is executed to control the first braking/driving torque of the right driving wheel 22R, and the second braking/driving torque of the left driving wheel 22L is limited based on the first slip torque. When the left drive wheel 22L is in contact with a road surface having a lower coefficient of road friction than the right drive wheel 22R, the torque control unit 44 controls the slip of the left drive wheel 22L based on the second slip torque TsL. The second slip suppression control that controls the second braking/driving torque of the left driving wheel 22L is executed, and the first braking/driving torque of the right driving wheel 22R is limited based on the second slip torque. When the first slip suppression control is being executed, the torque control unit 44 limits the braking/driving torque of each drive wheel 22R, 22L based on the first slip torque TsR, while controlling the absolute value of the first braking/driving torque. The vehicle 10 is turned by controlling the in- wheel motors 30R and 30L, respectively, so that a deviation occurs between the absolute value of the second braking and driving torque. When the second slip suppression control is being executed, the torque control unit 44 limits the braking/driving torque of each drive wheel 22R, 22L based on the second slip torque TsL, while controlling the absolute value of the first braking/driving torque. The vehicle 10 is turned by controlling the in- wheel motors 30R and 30L, respectively, so that a deviation occurs between the absolute value of the second braking and driving torque. According to this configuration, it is possible to turn the vehicle 10 while suppressing slips of the drive wheels 22R and 22L.

(3) The EVECU 40 includes a basic braking/driving torque setting section 41 and a torque deviation setting section 43. The basic braking/driving torque setting unit 41 sets the third basic braking/driving torque Tc based on the accelerator operation amount S1 and the brake operation amount S2 performed on the vehicle 10 in order to accelerate or decelerate the vehicle 10. The torque deviation setting unit 43 sets the correction torques ΔTcR and ΔTcL based on the left-right direction operation amount S34 performed on the vehicle 10 in order to turn the vehicle 10. When both the first slip suppression control and the second slip suppression control are not executed, the torque control unit 44 adds a predetermined value to the third basic braking/driving torque Tc based on the above equations f10 and f11. Setting either the first target braking/driving torque TR* or the second target braking/driving torque TL* by performing the correction, and also making a correction by subtracting a predetermined value from the third basic braking/driving torque Tc. The other of the first target braking/driving torque TR* and the second target braking/driving torque TL* is set. When the first slip suppression control is being executed, the torque control unit 44 sets the first target braking/driving torque TR* to the first slip torque TsR based on the above equations f14 and f15, and also sets the first target braking/driving torque TR* to the first slip torque TsR. The second target braking/driving torque TL* is set based on the calculated value obtained by correcting the four basic braking/driving torques Td using the correction torques ΔTcR and ΔTcL. When the second slip suppression control is being executed, the torque control unit 44 sets the second target braking/driving torque TL* to the second slip torque TsL based on the above equations f13 and f14, and also sets the fourth basic slip torque TsL. The first target braking/driving torque TR* is set based on the calculated value obtained by correcting the braking/driving torque Td using the correction torques ΔTcR and ΔTcL. According to this configuration, it is possible to easily set the first target braking/driving torque TR* and the second target braking/driving torque TL* that enable the vehicle 10 to turn while suppressing the slip of the vehicle 10.

(4) As the processing in steps S41 and S43 shown in FIG. When is smaller than the second slip torque TsL, it is determined that the right drive wheel 22R is in contact with a road surface having a lower coefficient of road friction than the left drive wheel 22L, and the process of step S44 is executed. Furthermore, as the processing in steps S41 and S43 shown in FIG. When it is smaller than the first slip torque TsR, it is determined that the left drive wheel 22L is in contact with a road surface having a lower coefficient of road friction than the right drive wheel 22R, and the process of step S45 is executed. Furthermore, when the vehicle 10 is decelerating, the torque control unit 44 determines which of the left driving wheel 22L and the right driving wheel 22R is on a road surface with a low coefficient of road friction, using the opposite criteria for determining whether the vehicle 10 is decelerating or accelerating. Determine if it is grounded. According to this configuration, it is possible to easily determine which of the right drive wheel 22R and the left drive wheel 22L is in contact with a road surface having a low coefficient of road friction.

(5) The EVECU 40 includes a speed calculation unit 42 that calculates an estimated value of the vehicle speed Vb based on at least one of the right drive wheel speed VR and the left drive wheel speed VL. When both the right drive wheel 22R and the left drive wheel 22L are slipping, the speed calculation unit 42 calculates the speed of the vehicle body based on the integral value of the acceleration A of the vehicle body 11, as shown in FIG. 6 and the above equation f1. Calculate speed Vb. According to this configuration, it is possible to estimate the right drive wheel speed VR and the left drive wheel speed VL without providing a sensor for detecting the speed of the vehicle body 11.

(6) When the vehicle 10 is accelerating, the speed calculation unit 42 calculates the integrated value of the right drive wheel speed VR, the left drive wheel speed VL, and the acceleration A of the vehicle body 11, as shown in step S12 in FIG. Among the speeds of the vehicle 10 estimated from the above, the smallest one is used as the estimated value of the vehicle body speed Vb. In addition, when the vehicle 10 is decelerating, the speed calculation unit 42 calculates the speed of the vehicle 10 that is the highest among the speeds of the vehicle 10 estimated from the integrated value of the right drive wheel speed VR, the left drive wheel speed VL, and the acceleration A of the vehicle body 11. The larger one is used as the estimated value of the vehicle speed Vb. According to this configuration, the vehicle speed Vb can be estimated more appropriately.

<Second embodiment>
Next, a second embodiment of the EVECU 40 will be described. Hereinafter, differences from the EVECU 40 of the first embodiment will be mainly explained.
In the vehicle 10 of the first embodiment, information on the right drive wheel speed VR and the left drive wheel speed VL, for example, is required to execute the process shown in FIG. Therefore, if an abnormality such as a momentary power failure occurs in the rotation sensors 34R and 34L shown in FIG. 3, it becomes impossible to appropriately detect the right drive wheel speed VR, left drive wheel speed VL, etc., and as a result, There is a risk that the indicated process may not be executed properly.

Therefore, in this embodiment, if the process shown in FIG. 5 or the slip suppression control cannot be executed appropriately due to an abnormality occurring in some sensor or device, or if the process or control is impossible to execute, In this case, the safety of the vehicle 10 is ensured by resetting the output torque of the in- wheel motors 30R and 30L to "0".

Specifically, the torque control unit 44 of this embodiment executes the process shown in FIG. 11. Note that the torque control unit 44 repeatedly executes the process shown in FIG. 11 at a predetermined cycle while the vehicle 10 is started.
As shown in FIG. 11, the torque distribution unit 440 first determines whether the slip control flag Xslip is "1" in step S60. When the slip control flag Xslip is "0", that is, when both the first slip suppression control and the second slip suppression control are not being executed, the torque distribution unit 440 temporarily ends the process shown in FIG. 11. .

In the process of step S60, the torque distribution unit 440 performs step S60 when the slip control flag As a process in S61, it is determined whether the absolute value |Y*-Y| of the deviation between the target yaw rate Y* and the actual yaw rate Y of the vehicle body 11 continues to be greater than or equal to a predetermined value Ya for a predetermined time or longer. When the vehicle 10 turns while the slip suppression control is being executed, if the process shown in FIG. Since the feedback control is performed based on the deviation of , a deviation is unlikely to occur between the actual yaw rate Y of the vehicle body 11 and the target yaw rate Y*. On the other hand, if an abnormality occurs in a sensor or the like of the vehicle 10, the process shown in FIG. Deviation from the actual yaw rate Y is likely to occur.

Therefore, in the case where the absolute value of the deviation |Y*-Y| continues for a predetermined time or more, the torque distribution unit 440 of the present embodiment determines that the absolute value |Y*-Y| of the deviation is positive in the process of step S61. If such a determination is made, it is determined that slip suppression control cannot be appropriately executed due to an abnormality in a sensor or the like. In this case, the slip control units 441 and 442 interrupt the slip suppression control as the process of step S62. That is, the first slip control unit 441 interrupts the first slip suppression control when it is being executed. The same applies to the second slip control section 442. The slip control units 441 and 442 set the slip control flag Xslip to "0" as processing in step S63 following step S62. Further, as the process of step S64, the torque distribution unit 440 sets the first target braking/driving torque TR* and the second target braking/driving torque TL* to "0", and continues this state for a predetermined period of time. As described above, the slip control of the right drive wheel 22R and the left drive wheel 22L is interrupted and the vehicle 10 is decelerated, so that simple fail-safe control can be executed. After a predetermined period of time has elapsed, the slip control units 441 and 442 release the first target braking/driving torque TR* and the second target braking/driving torque TL* from being set to "0". This allows the first slip control section 441 and the second slip control section 442 to perform the first slip suppression control and the second slip suppression control again.

On the other hand, if the torque distribution unit 440 makes a negative determination in the process of step S61, it determines that the situation is such that slip suppression control can be appropriately executed, and ends the process shown in FIG. 11.
According to the EVECU 40 of the vehicle 10 of the present embodiment described above, it is possible to further obtain the action and effect shown in (7) below.

(7) When executing the first slip suppression control for the right drive wheel 22R or the second slip suppression control for the left drive wheel 22L, the torque control unit 44 adjusts the actual yaw rate Y of the vehicle 10 and the target yaw rate Y*. When the absolute value of the deviation |Y*-Y| continues to be equal to or greater than a predetermined value, the first target braking/driving torque TR* and the second target braking/driving torque TL* are reset. As a result, when the vehicle 10 turns while the slip suppression control is being executed and the vehicle 10 cannot turn properly due to an abnormality in the sensor, etc., the first target braking/driving torque TR* and the second target braking/driving torque Since the torque TL* is reset, it is possible to ensure the safety of the vehicle 10.

<Other embodiments>
Note that the above embodiment can also be implemented in the following forms.
- Instead of controlling the braking/driving torque applied from the in- wheel motors 30R, 30L to the right drive wheel 22R and left drive wheel 22L, the torque control unit 44 controls the rotational speed of the right drive wheel 22R and the left drive Turning, forward and backward movement, and slip suppression of the vehicle 10 may be performed by controlling the rotational speeds of the wheels 22L, respectively. This rotational speed control can be realized by a control procedure similar to the control procedure shown in FIG.

- The configuration of the above embodiment is applicable not only to the vehicle 10 but also to any moving object.
- The EVECU 40 and its control method described in the present disclosure are implemented using one or more processors and memories that are programmed to perform one or more functions embodied by a computer program. It may also be realized by a dedicated computer. The EVECU 40 and its control method described in this disclosure may be implemented by a dedicated computer provided by configuring a processor that includes one or more dedicated hardware logic circuits. The EVECU 40 and the control method thereof described in the present disclosure include a processor configured by a combination of a processor and memory programmed to perform one or more functions and a processor including one or more hardware logic circuits. It may be implemented by one or more dedicated computers. A computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. Dedicated hardware logic circuits and hardware logic circuits may be implemented by digital circuits that include multiple logic circuits, or by analog circuits.

・This disclosure is not limited to the above specific examples. Design changes made by those skilled in the art to the specific examples described above are also included within the scope of the present disclosure as long as they have the characteristics of the present disclosure. The elements included in each of the specific examples described above, as well as their arrangement, conditions, shapes, etc., are not limited to those illustrated, and can be changed as appropriate. The elements included in each of the specific examples described above can be appropriately combined as long as no technical contradiction occurs.

<Additional notes>
Other features of the invention are as follows.
The torque deviation setting unit sets a target yaw rate, which is a target value of the yaw rate of the moving body, based on the second operation amount, and sets the target yaw rate, which is a target value of the yaw rate of the moving body, based on the deviation between the actual yaw rate of the moving body and the target yaw rate. A torque deviation is set, and when the torque control unit is executing control to suppress slip of the right drive wheel or the left drive wheel, the torque control unit determines the absolute value of the deviation between the actual yaw rate of the moving body and the target yaw rate. According to any one of claims 3 to 5, each value of the first target braking/driving torque and the second target braking/driving torque is reset when a state where the value continues to be equal to or higher than a predetermined value is continued. A control device for a mobile object.

The torque control section executes the first slip suppression control based on the fact that the absolute value of the deviation between the speed of the right drive wheel and the speed of the moving body becomes a predetermined value or more, and controls the speed of the left drive wheel. The second slip suppression control is executed based on the fact that the absolute value of the deviation between the speed of the moving body and the speed of the moving body becomes a predetermined value or more, and the second slip suppression control is performed to reduce at least one of the speed of the right drive wheel and the speed of the left drive wheel. The speed calculation unit further includes a speed calculation unit (42) that calculates an estimated value of the speed of the moving body based on the speed calculation unit, and the speed calculation unit is configured to calculate an estimated value of the speed of the moving body based on the moving direction of the moving body when both the right drive wheel and the left drive wheel slip. 7. The control device for a moving body according to claim 2, wherein the estimated value of the velocity of the moving body is calculated based on the integrated value of acceleration of the moving body.

Claims (9)

1. A first braking/driving torque applying part (30R) that applies a first braking/driving torque to the right driving wheel (22R), and a second braking/driving torque applying part (30R) that applies a second braking/driving torque to the left driving wheel (22L). A control device (40) for controlling a moving body (10) having a right driven wheel (21R) and a left driven wheel (21L) consisting of caster wheels (30L),
   comprising a torque control unit (44) that controls the first braking/driving torque applying unit and the second braking/driving torque applying unit,
   The torque control section controls the first braking/driving torque and the second braking/driving torque, or by controlling the rotational speed of the right drive wheel and the left drive wheel, respectively. A control device for a moving object that turns the moving object, moves it forward and backward, and suppresses slippage.
2. The torque control section includes:
   A first slip torque which is a braking/driving torque to be applied to the right driving wheel in order to make the slip ratio of the right driving wheel a predetermined target slip ratio, and a slip ratio of the left driving wheel to the target slip ratio. A second slip torque, which is a braking/driving torque to be applied to the left driving wheel, is calculated,
   When the right driving wheel is in contact with a road surface having a lower coefficient of road friction than the left driving wheel, the first braking/driving torque is controlled based on the first slip torque as control to suppress slip of the right driving wheel. executing a first slip suppression control that controls the second slip suppression control, and limiting the second braking/driving torque based on the first slip torque;
   When the left driving wheel is in contact with a road surface having a lower coefficient of road friction than the right driving wheel, the second braking/driving torque is controlled based on the second slip torque as control to suppress slip of the left driving wheel. executing second slip suppression control to control the second slip torque, and limiting the first braking/driving torque based on the second slip torque;
   When executing the first slip suppression control, while limiting the first braking/driving torque and the second braking/driving torque based on the first slip torque, the absolute value of the first braking/driving torque and the Turning the moving body by controlling the first braking/driving torque applying unit and the second braking/driving torque applying unit so that a deviation occurs between the absolute value of the second braking/driving torque,
   When executing the second slip suppression control, while limiting the first braking/driving torque and the second braking/driving torque based on the second slip torque, the absolute value of the first braking/driving torque and the The movement according to claim 1, wherein the first braking/driving torque applying unit and the second braking/driving torque applying unit are respectively controlled so that a deviation occurs between the absolute value of the second braking/driving torque, and the moving body is turned. body control device.
3. Setting a basic braking/driving torque that is a target value of the first braking/driving torque and the second braking/driving torque based on a first operation amount performed on the moving body to accelerate or decelerate the moving body. a basic braking/driving torque setting section (41),
   Torque deviation setting that sets a torque deviation that is a deviation between the first braking/driving torque and the second braking/driving torque based on a second operation amount performed on the movable body in order to turn the movable body. further comprising a part (43);
   The torque control section includes:
   controlling the first braking/driving torque applying unit so that the first braking/driving torque becomes a first target braking/driving torque;
   controlling the second braking/driving torque applying unit so that the second braking/driving torque becomes a second target braking/driving torque;
   When both the first slip suppression control and the second slip suppression control are not executed, the basic braking/driving torque is adjusted such that the torque deviation occurs between the first braking/driving torque and the second braking/driving torque. Setting either the first target braking/driving torque or the second target braking/driving torque by performing correction by adding a predetermined value to the base braking/driving torque, and correction by subtracting the predetermined value from the basic braking/driving torque. setting the other of the first target braking/driving torque and the second target braking/driving torque,
   When the first slip suppression control is being executed, the calculation is obtained by setting the first target braking/driving torque to the first slip torque and correcting the basic braking/driving torque by the torque deviation. setting the second target braking/driving torque based on the value;
   When the second slip suppression control is being executed, the second target braking/driving torque is set to the second slip torque, and the calculation is obtained by correcting the basic braking/driving torque by the torque deviation. The control device for a moving body according to claim 2, wherein the first target braking/driving torque is set based on the value.
4. When the moving body is accelerating and the first slip torque is smaller than the second slip torque, the torque control unit causes the right drive wheel to move to a road surface having a lower coefficient of road friction than the left drive wheel. When it is determined that the left driving wheel is in contact with the ground and the second slip torque is smaller than the first slip torque, it is determined that the left driving wheel is in contact with a road surface having a lower road surface friction coefficient than the right driving wheel. 4. A control device for a moving body according to item 2 or 3.
5. When the moving object is decelerating and the first slip torque is larger than the second slip torque, the torque control unit causes the right drive wheel to move to a road surface having a lower coefficient of road friction than the left drive wheel. When it is determined that the left driving wheel is in contact with the ground and the second slip torque is larger than the first slip torque, it is determined that the left driving wheel is in contact with a road surface having a lower road surface friction coefficient than the right driving wheel. 4. A control device for a moving body according to item 2 or 3.
6. The torque deviation setting section includes:
   setting a target yaw rate that is a target value of the yaw rate of the moving body based on the second operation amount;
   setting the torque deviation based on the deviation between the actual yaw rate of the moving body and the target yaw rate;
   When the torque control unit is executing control to suppress slip of the right drive wheel or the left drive wheel, the torque control unit may control the torque control unit to control the torque control unit when the absolute value of the deviation between the actual yaw rate of the moving body and the target yaw rate is equal to or greater than a predetermined value. The control device for a moving body according to claim 3, wherein each value of the first target braking/driving torque and the second target braking/driving torque is reset when a certain state continues.
7. The torque control section executes the first slip suppression control based on the fact that the absolute value of the deviation between the speed of the right drive wheel and the speed of the moving body becomes a predetermined value or more, and controls the speed of the left drive wheel. Executing the second slip suppression control based on the fact that the absolute value of the deviation between the speed and the speed of the moving body becomes a predetermined value or more,
   further comprising a speed calculation unit (42) that calculates an estimated value of the speed of the moving body based on at least one of the speed of the right drive wheel and the speed of the left drive wheel,
   The speed calculation unit calculates an estimated value of the speed of the moving body based on an integrated value of acceleration in the traveling direction of the moving body when both the right drive wheel and the left drive wheel slip. A control device for the mobile body described above.
8. The speed calculation section is
   Estimating the speed of the moving body based on the integrated value of acceleration in the moving direction of the moving body,
   When the moving body is accelerating, the speed of the moving body estimated from the integrated value of the speed of the right driving wheel, the speed of the left driving wheel, and the acceleration in the traveling direction of the moving body is the smallest. is used as an estimated value of the speed of the moving body,
   When the moving body is decelerating, the speed of the moving body estimated from the integrated value of the speed of the right driving wheel, the speed of the left driving wheel, and the acceleration in the traveling direction of the moving body is the greatest. The control device for a moving body according to claim 7, wherein a value of the velocity of the moving body is used as an estimated value of the speed of the moving body.
9. A first braking/driving torque applying part (30R) that applies a first braking/driving torque to the right driving wheel (22R), and a second braking/driving torque applying part (30R) that applies a second braking/driving torque to the left driving wheel (22L). A program for controlling a moving body (10) having a right driven wheel (21R) and a left driven wheel (21L) consisting of caster wheels (30L),
   to the computer,
   By controlling the first braking/driving torque and the second braking/driving torque, or by respectively controlling the rotational speed of the right drive wheel and the rotational speed of the left drive wheel, the turning, front and back of the moving object can be controlled. A program that executes processing for speeding up and suppressing slips.

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