Vehicle control device and vehicle control method

Abstract

This vehicle control device (10) controls the output of a left drive source (2L) and a right drive source (2R) of a vehicle, and comprises a first calculation unit (21), a second calculation unit (22), a sum mode feedback model, a difference mode feedback model, and a control unit (24). The first calculation unit (21) calculates a first sum-corresponding value that corresponds to the sum of a left target speed and a right target speed, and a first difference-corresponding value that corresponds to the difference between the same. The second calculation unit (22) calculates a second sum-corresponding value that corresponds to the sum of a left actual speed and a right actual speed, and a second difference-corresponding value that corresponds to the difference between the same. The control unit (24) uses a feedback sum indication torque and a feedback difference indication torque to control the respective torques of the left drive source and the right drive source.

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device and a vehicle control method for controlling a drive source mounted on a vehicle. [Background technology]

[0002] Conventionally, in a vehicle equipped with multiple drive sources, a method has been known in which a vehicle model that models the behavior of the drive force transmission system is used to control the operating state of each drive source while suppressing vibration in the drive force transmission system (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-103249 Summary of the Invention [Problem to be solved by the invention]

[0004] The behavior of the drivetrain is different when the vehicle is traveling straight and when it is turning. Therefore, it is necessary to develop separate controls for the vehicle traveling straight and turning. However, developing separate controls for the left and right drivetrains poses the problem that the control configuration tends to become complicated. Furthermore, the vehicle's driving state can be a complex state that combines both straight and turning states, which makes it difficult to improve controllability.

[0005] One of the objects of the present invention has been devised in light of the above-mentioned problems, and is to provide a vehicle control device and a vehicle control method that can improve controllability with a simple configuration. However, in addition to this object, another object of the present invention is to achieve effects derived from the respective configurations shown in the "Mode for Carrying Out the Invention" described below, which are effects that cannot be obtained with conventional technologies. [Means for solving the problem]

[0006] The disclosed vehicle control device and vehicle control method can be realized as the aspects or specific examples disclosed below, and solve at least some of the above problems. The disclosed vehicle control device is a vehicle control device for controlling outputs of a left drive source and a right drive source in a vehicle equipped with a left drive system including a left axle and left wheels to which power from a left drive source is transmitted, and a right drive system including a right axle and right wheels to which power from a right drive source is transmitted, the vehicle control device comprising: a first calculation unit that calculates a first sum equivalent value that corresponds to the sum of a left target speed that is a target speed of the left drive system or the left drive source and a right target speed that is a target speed of the right drive system or the right drive source, and calculates a first difference equivalent value that corresponds to the difference between the left target speed and the right target speed; a second calculation unit that calculates a second sum equivalent value that corresponds to the sum of a left actual speed that is an actual speed of the left drive system or the left drive source and a right actual speed that is an actual speed of the right drive system or the right drive source, and calculates a second difference equivalent value that corresponds to the difference between the left actual speed and the right actual speed; a sum mode feedback model that models the drive systems and the motion states of the left drive source and the right drive source, and that derives a feedback sum command torque by applying the first sum equivalent value and the second sum equivalent value to cause the actual speeds of the left drive system and the right drive system or the left drive source and the right drive source to follow their respective target speeds; a difference mode feedback model that models the motion states of the left drive system and the right drive system, and the left drive source and the right drive source when the vehicle is turning, and that derives a feedback difference command torque by applying the first difference equivalent value and the second difference equivalent value to cause the actual speeds to follow their respective target speeds; and a control unit that controls the torque of the left drive source and the right drive source using the feedback sum command torque and the feedback difference command torque.

[0007] The disclosed vehicle control method is a vehicle control method for controlling outputs of a left drive source and a right drive source in a vehicle equipped with a left drive system including a left axle and left wheels to which power from a left drive source is transmitted, and a right drive system including a right axle and right wheels to which power from a right drive source is transmitted, the vehicle control method comprising: preparing a sum mode feedback model that models the motion states of the left drive system and the right drive system, and the left drive source and the right drive source when the vehicle is traveling straight; and preparing a difference mode feedback model that models the motion states of the left drive system and the right drive system, and the left drive source and the right drive source when the vehicle is turning; calculating a first sum equivalent value that corresponds to the sum of a left target speed that is a target speed of the left drive system or the left drive source and a right target speed that is a target speed of the right drive system or the right drive source; and calculating a first difference phase equivalent value that corresponds to the difference between the left target speed and the right target speed. a second sum equivalent value equivalent to the sum of a left actual speed, which is the actual speed of the left drive system or the left drive source, and a right actual speed, which is the actual speed of the right drive system or the right drive source; and a second difference equivalent value equivalent to the difference between the left actual speed and the right actual speed. The first sum equivalent value and the second sum equivalent value are applied to the sum mode feedback model to obtain a feedback sum command torque for causing each actual speed of the left drive system and the right drive system or the left drive source and the right drive source to follow each target speed. The first sum equivalent value and the second sum equivalent value are applied to the difference mode feedback model to obtain a feedback difference command torque for causing each actual speed to follow each target speed. The torque of the left drive source and the right drive source is controlled using the feedback sum command torque and the feedback difference command torque. [Effects of the Invention]

[0008] According to the disclosed vehicle control device and vehicle control method, a sum model corresponding to when the vehicle is traveling straight and a difference model corresponding to when the vehicle is turning are separated, and a feedback sum command torque is determined based on a first sum equivalent value and a second sum equivalent value, and a feedback difference command torque is determined based on a first difference equivalent value and a second difference equivalent value, thereby making it possible to determine a command torque that achieves a target speed with a simple configuration. Therefore, in a drivetrain that has different characteristics when traveling straight and when turning, it is possible to control the state (behavior) of the drivetrain while accurately determining it, and it is possible to improve controllability with a simple configuration, making it possible to control the drivetrain in response to any driving condition. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram of a vehicle to which a vehicle control device is applied; [Figure 2] 1 is a schematic diagram showing an example of the structure of a vehicle drive system. [Figure 3] FIG. 3 is a velocity diagram of a power distribution mechanism of a vehicle having the structure shown in FIG. 2. [Figure 4] FIG. 2 is a block diagram showing the flow of a vehicle control method. [Figure 5] FIG. 5 is a block diagram showing an example of the conversion process of FIG. 4. [Figure 6] FIG. 5 is a block diagram showing an example of the inverse transformation and control process of FIG. 4. [Figure 7] FIG. 5 is a block diagram showing an example of the second conversion step of FIG. 4. [Figure 8] 1 is a schematic diagram illustrating the structure of a left drive train and a right drive train of a vehicle. FIG. [Figure 9] (A) is a schematic diagram of the sum model, and (B) is a schematic diagram of the difference model. [Figure 10] FIG. 1 is a schematic diagram for considering the behavior of a vehicle when traveling straight. [Figure 11] FIG. 2 is a schematic diagram showing the relationship between torque and speed when the vehicle is traveling straight. [Figure 12] FIG. 2 is a schematic diagram showing the relationship between torque and speed when the vehicle is turning. [Figure 13]FIG. 10 is a block diagram showing the flow of a vehicle control method according to a first modified example. [Figure 14] 10 is a graph for explaining a deviation between a motor speed and a wheel speed. [Figure 15] FIG. 10 is a block diagram showing the flow of a vehicle control method according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] The types of vehicles in which the disclosed vehicle control device and vehicle control method can be used include, for example, engine vehicles (gasoline vehicles, diesel vehicles), electric vehicles, and hybrid vehicles, which run by driving left and right wheels (left and right drive wheels) using at least one drive source (internal combustion engine or motor), and preferably run by driving left and right wheels (left and right drive wheels) using multiple drive sources. Here, one of the multiple drive sources is referred to as the left drive source, and the other drive source is referred to as the right drive source. Also, of the left and right wheels, one located on the left side of the vehicle is referred to as the left wheel, and the other is referred to as the right wheel. The disclosed vehicle control device and vehicle control method can be used to control a vehicle equipped with a left drive system including a left axle and left wheels to which power is transmitted from the left drive source, and a right drive system including a right axle and right wheels to which power is transmitted from the right drive source.

[0011] The layout of each of the left and right drive sources may or may not be set to correspond to the left-right direction defined based on the vehicle's direction of travel. Furthermore, the left and right drive systems may operate independently of each other, or may be connected to each other via a transmission mechanism or a power distribution mechanism. The disclosed vehicle control device and vehicle control method can be used to control in-wheel motor vehicles in which the left and right wheels are driven by individual motors, as well as torque vectoring vehicles in which the left and right wheels can transmit driving force or torque to each other. [Example]

[0012] [1. Configuration] A vehicle control device 10 according to an embodiment is mounted on a vehicle 1 shown in FIG. 1. The vehicle 1 includes left and right wheels 5 (wheels) arranged side by side in the vehicle width direction, a power distribution mechanism 3 (differential mechanism) that applies a torque difference to the left and right wheels 5, and a pair of motors 2 connected to the power distribution mechanism 3. In the drawings of the embodiment, the letters L and R added to the numeral symbols indicate the location of the element associated with the symbol (whether it is on the left or right side of the vehicle 1). For example, 5L indicates one of the left and right wheels 5 (the left wheel) located on the left side of the vehicle 1, and 5R indicates the other (the right wheel) located on the right side. The positions of the left and right wheels 5 in the longitudinal direction do not matter, and they may be the front or rear wheels of the vehicle 1.

[0013] The motor 2 (drive source) has the function of driving at least either the front wheels or the rear wheels of the vehicle 1, and can also have the function of driving all four wheels. Of the pair of motors 2, one located on the left side is the left motor 2L (left drive source), and the other located on the right side is the right motor 2R (right drive source). The left motor 2L and the right motor 2R operate independently of each other and can individually output drive forces of different magnitudes. These motors 2 are connected to the power distribution mechanism 3 via a pair of speed reduction mechanisms that are separately provided from each other.

[0014] The vehicle 1 is equipped with a power distribution mechanism 3 that amplifies the torque difference between the pair of motors 2 and distributes it to each of the left and right wheels 5. The power distribution mechanism 3 in this embodiment is a differential mechanism with a yaw control function (AYC (Active Yaw Control) function) and is interposed between an axle 4 (left axle 4L, left axle) connected to the left wheel 5L and an axle 4 (right axle 4R, right axle) connected to the right wheel 5R. The yaw control function actively controls the distribution ratio of the driving force (driving torque) between the left and right wheels 5 to adjust the yaw moment and stabilize the posture of the vehicle 1. The power distribution mechanism 3 includes a planetary gear mechanism, a differential gear mechanism, and the like. A vehicle drive system including the pair of motors 2 and the power distribution mechanism 3 is also called a DM-AYC (Dual Motor AYC) system.

[0015] As shown in FIG. 2, the power distribution mechanism 3 includes a pair of speed reduction mechanisms (gear trains surrounded by dashed lines in FIG. 2) and a transmission mechanism (gear trains surrounded by dashed lines in FIG. 2) that reduce the rotational speed of the motor 2. The speed reduction mechanism is a mechanism that increases the torque (driving force) output from the motor 2 by reducing the torque. The reduction ratio G of the speed reduction mechanism is set appropriately depending on the output characteristics and performance of the motor 2. If the torque performance of the motor 2 is sufficiently high, the speed reduction mechanism may be omitted. The transmission mechanism is a mechanism that amplifies the difference in torque transmitted to each of the left and right wheels 5.

[0016] The transmission mechanism of the power distribution mechanism 3 shown in FIG. 2 includes a pair of planetary gear mechanisms. These planetary gear mechanisms have a structure in which a planetary gear provided on each carrier and its rotation shaft are connected to each other. Each carrier supports the planetary gear so that it can rotate and also supports the planetary gear so that it revolves around the sun gear. Furthermore, driving forces transmitted from the left and right motors 2 are input to the ring gear and sun gear of one planetary gear mechanism. Driving forces transmitted to the left and right wheels 5 are extracted from the sun gear and carrier of the other planetary gear mechanism. Note that the structure of the power distribution mechanism 3 shown in FIG. 2 is merely one example for achieving a yaw control function, and other known structures may also be used.

[0017] In addition, J in Fig. 2 M is the motor inertia (moment of inertia of motor 2), J w represents the wheel inertia (moment of inertia of the left and right wheels 5). LM is the left motor input torque (left command torque), T Lm is the left motor input torque after deceleration by the reduction mechanism, ω LM is the left motor angular velocity, ω Lm is the angular velocity of the left motor after deceleration by the reduction mechanism, T Lin is the torque on the left drive side, T Lds is the left axle torque, T LL is the left wheel load torque, ω Lds is the left driving side angular velocity, ω LL is the left wheel angular velocity (target velocity of the left wheel 5L). Similarly, for the parameters of the right drive system, TRM is the right motor input torque (right command torque), T R m is the right motor input torque after deceleration by the reduction mechanism, ω RM is the right motor angular velocity, ω Rm is the angular velocity of the right motor after deceleration by the reduction mechanism, T Rin is the right drive torque, T Rds is the right axle torque, T RL is the right wheel load torque, ω Rds is the right drive side angular velocity, ω RL is the right wheel angular velocity (target velocity of the right wheel 5R).

[0018] Fig. 3 is a speed diagram of the power distribution mechanism 3. b1 and b2 shown in Figs. 2 and 3 represent torque difference amplification factors (deceleration rate, differential reduction ratio) determined according to the structure of the gears built into the power distribution mechanism 3. The torque difference amplification factor related to power transmission from the left motor 2L to the right wheel 5R is b1, and the torque difference amplification factor related to power transmission from the left motor 2L to the left wheel 5L is b1+1. Furthermore, the torque difference amplification factor related to power transmission from the right motor 2R to the left wheel 5L is b2, and the torque difference amplification factor related to power transmission from the right motor 2R to the right wheel 5R is b2+1.

[0019] As shown in FIG. 1 , each of the pair of motors 2 is electrically connected to a battery 7 via an inverter 6 (6L, 6R). The inverter 6 is a converter (DC-AC inverter) that converts between power (DC power) of a DC circuit on the battery 7 side and power (AC power) of an AC circuit on the motor 2 side. The battery 7 is, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery, and is a secondary battery that can supply a high-voltage DC current of several hundred volts. When the motor 2 is powered, the DC power is converted into AC power by the inverter 6 and supplied to the motor 2. When the motor 2 is generating power, the generated power is converted into DC power by the inverter 6 and charged into the battery 7. The operating state of the inverter 6 is controlled by a vehicle control device 10.

[0020] The vehicle control device 10 is an electronic control unit (ECU) mounted on the vehicle 1. The vehicle control device 10 is one of the left motors 2L (left drive source). In a vehicle 1 equipped with a left drivetrain including a left axle 4L and a left wheel 5L to which power is transmitted from a right motor 2R (right drive source), and a right drivetrain including a right axle 4R and a right wheel 5R to which power is transmitted from a right motor 2R (right drive source), the control unit has the function of controlling the output of each of the left motor 2L and the right motor 2R.

[0021] The vehicle control device 10 incorporates a processor (central processing unit), memory (main memory), storage device, interface device, etc. (not shown), which are communicably connected to each other via an internal bus. The contents of the determinations and controls performed by the vehicle control device 10 are recorded and saved in the memory as firmware or application programs, and when the programs are executed, the contents of the programs are expanded in the memory space and executed by the processor.

[0022] The vehicle control device 10 is connected to an accelerator opening sensor 14, a brake sensor 15, a steering angle sensor 16, a resolver 17, and a wheel speed sensor 18. The accelerator opening sensor 14 is a sensor that detects the amount of depression of the accelerator pedal (accelerator opening) and the depression speed. The brake sensor 15 is a sensor that detects the amount of depression of the brake pedal (brake pedal stroke) and the depression speed. The steering angle sensor 16 is a sensor that detects the steering angle of the left and right wheels 5 (actual steering angle or steering angle of the steering wheel).

[0023] The resolvers 17 (17L, 17R) are sensors that detect the speed of the motors 2 and are individually provided for each of the pair of motors 2. The resolvers 17 output information on the rotation angle of the motors 2 as two-phase AC voltages. The speed of the motors 2 is determined from changes in these AC voltages over time. The wheel speed sensors 18 (18L, 18R) are sensors that detect the speed of the axles 4. The vehicle control device 10 controls the operating state of the inverters 6 (6L, 6R) based on the information detected by the various sensors 14 to 18, thereby controlling the output of the pair of motors 2 (2L, 2R). Note that instead of the resolvers 17, other sensors (such as hall sensors or encoders) with different internal structures or operating principles may be used.

[0024] [2. Vehicle control device] FIG. 4 is a schematic block diagram showing the flow of control (output control for the motor 2 to which the vehicle control method of the embodiment is applied) performed by the vehicle control device 10. A sum model and a difference model are stored in advance in the storage device of the vehicle control device 10. That is, in this vehicle control method, the sum model and the difference model are first prepared. The sum model is a model of the motion states of the left and right drive systems, and the left drive source (left motor 2L) and right drive source (right motor 2R) when the vehicle 1 is traveling straight, and the difference model is a model of the motion states of the left and right drive systems, and the left drive source (left motor 2L) and right drive source (right motor 2R) when the vehicle 1 is turning.

[0025] The sum model includes a sum-mode FF (feedforward) model and a sum-mode FB (feedback) model. The vehicle control device 10 of this embodiment uses both the sum-mode FF model and the sum-mode FB model (performing both step A3 and step A9 in FIG. 4) to accurately grasp the motion states of the left and right drivetrains when the vehicle 1 is traveling straight. Note that it is also possible to omit control based on the sum-mode FF model (step A3) and perform only control based on the sum-mode FB model (step A9).

[0026] Similarly, the differential model includes a differential mode FF model and a differential mode FB model. The vehicle control device 10 of this embodiment uses the differential mode FF model and the differential mode FB model together (performing both step A4 and step A10 in FIG. 4) to accurately grasp the motion states of the left and right drive trains when the vehicle 1 turns. Note that it is also possible to omit the control based on the differential mode FF model (step A4) and perform only the control based on the differential mode FB model (step A10).

[0027] The sum mode FF model is a model for determining the FF sum command torque (feedforward sum command torque) by applying a first sum equivalent value. Control that determines the FF sum command torque based on the sum mode FF model is called FF wheel speed control (sum). FF wheel speed control (sum) is feedforward control (open-loop control). In contrast, the sum mode FB model is a model for determining the FB sum command torque (feedback sum command torque) by applying a first sum equivalent value and a second sum equivalent value. Control that determines the FB sum command torque based on the sum mode FB model is called FB wheel speed control (sum). FB wheel speed control (sum) is feedback control (closed-loop control).

[0028] The first sum equivalent value is a general term for a value equivalent to the sum of a left target speed representing the target speed of the left drive system or left motor 2L among parameters (representing the behavior of the left drive system) including input parameters or output parameters of the left drive system, and a right target speed representing the target speed of the right drive system or right motor 2R among parameters (representing the behavior of the right drive system) including input parameters or output parameters of the right drive system. The first sum equivalent value includes not only a simple sum, but also a value obtained by multiplying the sum by a predetermined coefficient, half the sum (arithmetic mean value), etc. The second sum equivalent value is a general term for a value equivalent to the sum of the actual speed of the left drive system or left motor 2L and the actual speed of the right drive system or right motor 2R. Like the first sum equivalent value, the second sum equivalent value includes not only a simple sum, but also a value obtained by multiplying the sum by a predetermined coefficient, half the sum (arithmetic mean value), etc.

[0029] The FF sum command torque derived from the sum mode FF model means a torque equivalent to the sum of the torques required to make the actual speeds of the left and right drive systems (or the left motor 2L and right motor 2R) follow their respective target speeds when the vehicle 1 is traveling straight. Also, the FB sum command torque derived from the sum mode FB model means a torque as a feedback control amount required to bring the difference (deviation) between the first sum equivalent value and the second sum equivalent value closer to zero.

[0030] The difference mode FF model is a model for determining the FF differential command torque (feedforward differential command torque) by applying a first difference equivalent value. Control that determines the FF differential command torque based on the difference mode FF model is called FF wheel speed control (differential). FF wheel speed control (differential) is feedforward control (open-loop control). In contrast, the difference mode FB model is a model for determining the FB differential command torque (feedback differential command torque) by applying a first difference equivalent value and a second difference equivalent value. Control that determines the FB differential command torque based on the difference mode FB model is called FB wheel speed control (differential). FB wheel speed control (differential) is feedback control (closed-loop control).

[0031] The first difference equivalent value is a general term for values ​​corresponding to the difference between a left target speed representing a target speed of the left drive system or left motor 2L among parameters (representing the behavior of the left drive system) including input parameters or output parameters of the left drive system, and a right target speed representing a target speed of the right drive system or right motor 2R among parameters (representing the behavior of the right drive system) including input parameters or output parameters of the right drive system. The first difference equivalent value includes not only the simple difference, but also a value obtained by multiplying the difference by a predetermined coefficient, half the difference, etc. The second difference equivalent value is a general term for values ​​corresponding to the difference between the actual speed of the left drive system or left motor 2L and the actual speed of the right drive system or right motor 2R. Like the first difference equivalent value, the second difference equivalent value includes not only the simple difference, but also a value obtained by multiplying the difference by a predetermined coefficient, half the difference, etc.

[0032] The FF differential command torque derived from the differential mode FF model refers to a torque equivalent to the difference between the torques required to make the actual speeds of the left and right drive systems (or the left motor 2L and right motor 2R) follow their respective target speeds when turning the vehicle 1. Also, the FB differential command torque derived from the differential mode FB model refers to a torque as a feedback control amount required to bring the difference (deviation) between the first difference equivalent value and the second difference equivalent value closer to zero.

[0033] Steps A1 and A2 in Fig. 4 correspond to a process (conversion process) of calculating a first sum equivalent value and a first difference equivalent value based on the left target speed and the right target speed. The values ​​of the left target speed and the right target speed are calculated by a known pre-stage control. In the pre-stage control, the left target speed and the right target speed are calculated based on, for example, information detected by the various sensors 14 to 18, and have magnitudes corresponding to the running state of the vehicle 1 and the driver's intention (intention to accelerate, decelerate, turn, etc.).

[0034] FIG. 5 is a block diagram showing a specific example of steps A1 and A2 (conversion process) in FIG. 4. LL (Or, left motor angular velocity ω LM ) is a specific example of the left target velocity, and "right wheel target angular velocity ω RL (or right motor angular velocity ω RM ) is a specific example of the right target speed. In step A1, half of the sum of the target speeds of the left and right wheels 5 is calculated, and the sum mode wheel angular speed ω SL (or sum mode motor angular velocity ω SM ) is output as the sum mode wheel angular velocity ω SL (or sum mode motor angular velocity ω SM ) corresponds to the first sum equivalent value transmitted to steps A3 and A9 in FIG. 4. Also, in step A2, half of the difference between the target speeds of the left and right wheels 5 is calculated, and the difference mode wheel angular velocity ω DL (or, the difference mode motor angular velocity ω DM ) is output as the differential mode wheel angular velocity ω DL (or, the difference mode motor angular velocity ω DM) corresponds to the first difference equivalent value transmitted to steps A4 and A10 in FIG.

[0035] Step A3 in FIG. 4 corresponds to a process (FF wheel speed control (sum)) in which a first sum equivalent value is applied to the sum mode FF model to obtain an FF sum command torque. Step A4 corresponds to a process (FF wheel speed control (differential)) in which a first difference equivalent value is applied to the difference mode FF model to obtain an FF difference command torque. Similarly, step A9 corresponds to a process (FB wheel speed control (sum)) in which the first sum equivalent value and the second sum equivalent value are applied to the sum mode FB model to obtain an FB sum command torque for zeroing the difference between the first sum equivalent value and the second sum equivalent value. Step A10 corresponds to a process (FB wheel speed control (differential)) in which the first difference equivalent value and the second difference equivalent value are applied to the difference mode FB model to obtain an FB difference command torque for zeroing the difference between the first difference equivalent value and the second difference equivalent value.

[0036] Then, the sum of the FF sum command torque and the FB sum command torque is transmitted to steps A5 and A6 as the final sum command torque, and the sum of the FF difference command torque and the FB difference command torque is transmitted to steps A5 and A6 as the final difference command torque. Steps A5 and A6 correspond to processes (inverse conversion / control processes) for calculating the left command torque and the right command torque using the sum command torque and the difference command torque, and controlling the torques of the left motor 2L and the right motor 2R based on these left command torque and right command torque.

[0037] FIG. 6 is a block diagram showing a specific example of steps A5 and A6 (inverse conversion and control process) in FIG. 4. Sin " is a specific example of the sum torque, and "differential mode driving side torque T Din " is a specific example of the differential torque. In step A5, the sum mode driving side torque T Sin Difference mode drive torque T Din Half of the value obtained by subtracting LM The output is the left motor input torque T LMcorresponds to the left command torque in FIG. 4. In addition, in step A6, the sum mode driving side torque T Sin and differential mode drive torque T Din Half of the sum of these is calculated, and the right motor input torque T RM The right motor input torque T RM corresponds to the right indicated torque in Figure 4.

[0038] 4 correspond to a step (second conversion step) of calculating a second sum equivalent value and a second difference equivalent value based on the left actual speed, which is the actual speed of the left drivetrain (or left motor 2L), and the right actual speed, which is the actual speed of the right drivetrain (or right motor 2R). The left actual speed and the right actual speed are detected by, for example, the left and right wheel speed sensors 18L and 18R. Fig. 7 is a block diagram showing a specific example of steps A7 and A8 (second conversion step) in Fig. 4. In step A7, half of the sum of the left actual speed and the right actual speed is calculated and output as a second sum equivalent value. In addition, in step A8, half of the value obtained by subtracting the left actual speed from the right actual speed is calculated and output as a second difference equivalent value.

[0039] Next, a specific configuration for implementing the above control will be described. As shown in Fig. 1, a first calculation unit 21, a second calculation unit 22, a storage unit 23, and a control unit 24 are provided inside the vehicle control device 10. These elements are shown by conveniently classifying the functions of the vehicle control device 10. These elements may be written as independent programs for realizing the functions of each element. Alternatively, multiple elements may be combined and written as a single composite program.

[0040] The first calculation unit 21 calculates a first sum equivalent value and a first difference equivalent value. The first sum equivalent value and the first difference equivalent value are calculated based on a left target speed and a right target speed corresponding thereto. The left target speed includes, for example, a left motor angular speed ω LM , Left motor angular velocity (after deceleration) ω Lm , left drive side angular velocity ω Lds , left wheel angular velocity ω LL(left wheel target speed), etc. Similarly, the right target speed includes, for example, the right motor angular speed ω RM , Right motor angular velocity (after deceleration) ω Rm , right drive side angular velocity ω Rds , right wheel angular velocity ω RL (Right wheel target speed), etc.

[0041] The first sum equivalent value is, for example, the sum mode motor angular velocity ω SM , Sum mode motor angular velocity (after deceleration) ω Sm , sum mode drive side angular velocity ω Sds , sum mode wheel angular velocity ω SL Similarly, the first difference equivalent value includes, for example, the difference mode motor angular velocity ω DM ,Difference mode motor angular velocity (after deceleration) ω Dm , differential mode drive side angular velocity ω Dds , difference mode wheel angular velocity ω DL etc. are included.

[0042] Sum mode motor angular velocity ω SM and the difference mode motor angular velocity ω DM Each of the left motor angular velocity ω LM and right motor angular velocity ω RM The sum mode motor angular velocity (after deceleration) is calculated based on Sm and differential mode motor angular velocity (after deceleration) ω Dm Each of the left motor angular velocity (after deceleration) ω Lm and right motor angular velocity (after deceleration) ω Rm Below is an example of a calculation formula in which half the sum of the left target speed and the right target speed is the first sum equivalent value, and half the difference between the left target speed and the right target speed is the first difference equivalent value.

[0043]

number

[0044] The second calculation unit 22 calculates a second sum equivalent value and a second difference equivalent value. The second sum equivalent value and the second difference equivalent value are calculated based on a left actual speed, which is the actual speed of the left drive system or the left motor 2L, and a right actual speed, which is the actual speed of the right drive system or the right motor 2R. The left actual speed includes, for example, a left motor angular velocity ω LM , Left motor angular velocity (after deceleration) ω Lm , left drive side angular velocity ω Lds , left wheel angular velocity ω LL (left wheel actual speed), etc. Similarly, the right target speed includes various actual speeds related to the driving of the left wheel 5L, such as the right motor angular speed ω RM , Right motor angular velocity (after deceleration) ω Rm , right drive side angular velocity ω Rds , right wheel angular velocity ω RL (right wheel actual speed), etc. The calculation formula shown in [Formula 1] above can be used as a calculation formula in the case where half of the sum of the left actual speed and the right actual speed is used as the second sum equivalent value, and half of the difference between the left actual speed and the right actual speed is used as the second difference equivalent value.

[0045] The storage unit 23 stores sum models (sum mode FF model, sum mode FB model) that model the motion states of the left and right drive systems and the left drive source (left motor 2L) and right drive source (right motor 2R) when the vehicle 1 is traveling straight, and difference models (difference mode FF model, difference mode FB model) that model the motion states of the left and right drive systems and the left drive source (left motor 2L) and right drive source (right motor 2R) when the vehicle 1 is turning. Before describing the sum model and difference model, a schematic structure of the left and right drive systems of the vehicle 1 will be described.

[0046] FIG. 8 is a schematic diagram showing the structure of the left and right drive trains of the vehicle 1. Each of the left axle 4L and the right axle 4R has a spring (axle stiffness K s ) and damper (axle viscous D s ) can be considered as a structure in which J in Figure 8 is connected in parallel. LM is the inertia of the power distribution mechanism 3 side (drive side) for the left axle 4L, J Lwis the inertia of the left wheel 5L (load side) relative to the left axle 4L, J RM is the inertia of the power distribution mechanism 3 side (drive side) for the right axle 4R, J Rw is the inertia of the right wheel 5R (load side) relative to the right axle 4R. Also, in FIG. 8, the left driving side angular velocity ω Lds Derivative value of (left driving side angular acceleration), left wheel angular velocity ω LL The differential value (left wheel angular acceleration), right drive side angular velocity ω Rds Differential value (right drive side angular acceleration), right wheel angular velocity ω R L The differential value (right wheel angular acceleration) is also shown.

[0047] Based on the above schematic diagrams, the configuration of the sum model is modeled as shown in Fig. 9(A), and the configuration of the difference model is modeled as shown in Fig. 9(B). The sum model is preferably used for vibration damping control and slip control for the axles 4 and left and right wheels 5 related to the straight-line running of the vehicle 1, and the difference model is preferably used for vibration damping control and slip control for the axles 4 and left and right wheels 5 related to the turning of the vehicle 1. Note that, although in this embodiment, the sum model and the difference model are both two-inertia system models, each may be configured as a multi-inertia system model consisting of three or more moments of inertia and spring dampers.

[0048] As shown in Figure 9(A), the sum model uses the driving inertia J SM and stiffness K s and viscosity D s The spring damper is designed with the load side inertia (sum mode wheel nominal inertia) J SL The drive inertia J SM is the inertia J of the drive source (left motor 2L and right motor 2R). M For example, J SM =G 2 J M In addition, the load inertia J SL is calculated based on the vehicle weight M (wheel equivalent). SM and load inertia J SL Friction may also be taken into consideration when calculating the equation of motion for the sum model.

[0049]

number

[0050] As shown in Figure 9(B), the difference model uses the drive-side inertia J, which is the equivalent inertia when a difference between the left and right wheels occurs (when turning). DM and stiffness K s and viscosity D s The spring damper is designed with the load side inertia (differential mode wheel nominal inertia) J DL The drive inertia J DM is the inertia J of the drive source (left drive source and right drive source) M and the torque difference amplification factor (b1, b2, etc.) of the power distribution mechanism 3, DM =(2b1+1) 2 G 2 J M In addition, the load inertia J DL is calculated based on the yaw inertia (wheel equivalent) of the vehicle 1. Note that the drive-side inertia J DM and load inertia J DL Friction may also be taken into consideration when calculating the equation of motion for the differential model.

[0051]

number

[0052] By applying the first sum equivalent value to the sum model, an FF sum command torque equivalent to the sum of torques required to make the actual speeds of the left and right drive trains (or the left motor 2L and right motor 2R) follow the target speed when the vehicle 1 is traveling straight is obtained. Also, by applying the first sum equivalent value and the second sum equivalent value to the sum model, an FB sum command torque is obtained. For example, when the sum mode wheel angular velocity ω is applied to the sum mode FF model, SL As a result of applying Sin is obtained as the FF sum command torque. In addition, the sum mode wheel angular velocity ω SLAs a result of applying the second sum equivalent value, the FB sum command torque is obtained. The sum of the FF sum command torque and the FB sum command torque becomes the final sum command torque.

[0053] The same applies to the difference model, and by applying the first difference equivalent value to the above difference model, an FF difference command torque corresponding to the difference in torque required to make the actual speeds of the left drive system and the right drive system (or the left motor 2L and the right motor 2R) follow the target speed when the vehicle 1 is turning is obtained. Also, by applying the first difference equivalent value and the second difference equivalent value to the above difference model, an FB difference command torque is obtained. For example, when the difference mode wheel angular velocity ω is applied to the difference mode FF model, DL As a result of applying Din is obtained as the FF differential command torque. Also, the differential mode wheel angular velocity ω DL As a result of applying the second difference equivalent value, the FB difference instruction torque is obtained. The sum of the FF difference instruction torque and the FB difference instruction torque becomes the final difference instruction torque.

[0054] The control unit 24 obtains a sum command torque and a difference command torque by appropriately applying the first sum equivalent value, the second sum equivalent value, the first difference equivalent value, and the second difference equivalent value calculated by the first calculation unit 21 and the second calculation unit 22 to the two sum models and two difference models stored in the memory unit 23, respectively, and controls the outputs of the left motor 2L and the right motor 2R using the sum command torque and the difference command torque. The control unit 24 controls the operating state of the inverter 6 so that the sum command torque and the difference command torque are obtained by driving the pair of motors 2 (i.e., so that both the sum command torque and the difference command torque can be achieved). This makes it easier to accurately control the motion states of the left drive system and the right drive system so that they are in the desired states.

[0055] Here, the sum mode wheel angular velocity ω calculated based on the target angular velocities (target wheel speeds) of the left and right wheels 5 is SL and the difference mode wheel angular velocity ω DL As a result of applying these to the sum model and the difference model, the sum mode drive torque TSin and differential mode drive torque T Din The case where the sum mode driving torque T Sin and differential mode drive torque T Din The torque to be output by each of the pair of motors 2 is calculated based on the above equation, and the pair of inverters 6 are driven so as to obtain that torque.

[0056] Sum mode drive torque T Sin and differential mode drive torque T Din The calculation of the torque of each motor 2 based on the first sum equivalent value and the first difference equivalent value can be realized by performing the inverse calculation of the calculation of the first sum equivalent value and the first difference equivalent value. For example, if the torque of each motor 2 to be calculated is "left motor input torque T LM , right motor input torque T RM " and the torque when these torques are transmitted to axle 4 is defined as "left drive side torque T Lin , Right drive torque T Rin Next, let us consider the left drive torque T L in and right drive torque T Rin The sum of these is the sum mode drive torque T Sin and the left drive torque T Lin and right drive torque T Rin The difference between the differential mode drive torque T Di n The torque on the left drive side, T, is Lin and right drive torque T Rin Next, the left driving side torque T Lin and right drive torque T Rin Left motor input torque T corresponding to LM and right motor input torque T RM Calculate.

[0057] Then, the calculated left motor input torque T LM and right motor input torque T RMEach inverter 6 is driven so that the actual speed of the motor 2 and the left and right wheels 5 accurately tracks the target speed. This control improves wheel speed controllability. Furthermore, because the wheel speed tends to match the target speed even when a disturbance is input, the wheel speed is less likely to change suddenly even when the frictional resistance of the road surface or the driving force changes, and slippage is suppressed.

[0058] [3. Examples of sum model and difference model] [A. Load side transfer function (sum model)] FIG. 10 is a schematic diagram for deriving the load side inertia when the vehicle 1 is traveling straight. Here, the vehicle speed when the vehicle 1 is traveling straight is V x ,Wheel speed (forward speed of left and right wheels 5) is V SL , the vehicle weight is M, the wheel angular velocity (sum mode wheel speed) is ω SL , the driving force of the left and right wheels 5 is F Sx , the wheel radius is r. The sum mode wheel load torque T SL The sum mode axle torque T (torque corresponding to the reaction force from the road surface and the driving force) is the driving torque Sds If we linearize it assuming that it is determined by the following equation, the following equation holds:

[0059]

number

[0060] Based on the above equation, the transfer function of the sum mode load side (a relational expression including a transfer function that represents the input / output characteristics of a two-inertia system related to the sum model) can be obtained. Sn is the sum mode wheel nominal slip ratio (the wheel nominal slip ratio in the sum model).

number

[0061] FIG. 11 is a schematic diagram showing the relationship between torque and speed in the sum model. Here, the sum mode wheel load torque T SL , sum mode wheel angular velocity ω SL, sum mode axle torque T Sd s , sum mode drive torque T Sin , sum mode drive side angular velocity ω Sds The relationship between J and M is the motor inertia, D M is the motor viscosity, J L is the inertia of the power distribution mechanism 3 (drive side) relative to the axle 4, D L is the load-side viscosity.

[0062] Sum mode drive side angular velocity ω Sds is the sum mode drive torque T Sin From sum mode axle torque T Sds The value obtained by subtracting "G -1 " and "1 / (J M ·s+D M )" and "G -1 " is calculated by multiplying Sum mode axle torque T Sds is the sum mode drive side angular velocity ω Sds From sum mode wheel angular velocity ω SL The value obtained by subtracting "(K s / s)+D s " is calculated by multiplying In addition, the sum mode wheel angular velocity ω SL is the sum mode axle torque T Sds From sum mode wheel load side torque T SL The value obtained by subtracting 1 / (J L ·s+D L ) is calculated.

[0063] [B. Load side transfer function (difference model)] The yaw rate of vehicle 1 when turning is γ, the tread is d, and the difference in left and right wheel speed is V. Dx Also, V x is the vehicle speed, V rlx is the left wheel reference wheel speed, V rrx is the reference wheel speed of the right wheel. Assuming the steering angle is zero, the yaw rate γ and the difference mode wheel angular velocity ω DL Considering the relationship between

[0064]

number

[0065] The equations of motion for the differential mode drive side, yaw motion, and lateral motion are formulated as follows: f is the steering angle, a y is the lateral acceleration, I is the yaw inertia of vehicle 1, C f is the front wheel cornering power, C r is rear wheel cornering power, f is the distance between the center of gravity and the front axle, l r is the distance between the center of gravity and the rear axle, β is the vehicle slip angle, F Dx is the difference between the left and right driving forces, λ D is the slip ratio in the difference model.

[0066]

number

[0067] Here, in order to model the transitional state of the vehicle 1 from a straight traveling state to a turning state, the steering angle δ f and lateral acceleration a y Assuming that is zero, the following transfer function on the differential mode load side (a relational expression including a transfer function that represents the input / output characteristics of a two-inertia system related to the differential model) is obtained:

number

[0068] FIG. 12 is a schematic diagram showing the relationship between torque and speed in the differential model. Here, the differential mode wheel load torque T DL , difference mode wheel angular velocity ω DL ,Differential mode axle torque T Dd s , Differential mode drive torque T Din , differential mode drive side angular velocity ω Dds The relationship is shown. Differential mode drive side angular velocity ω Dds is the differential mode drive torque T DinDifference mode axle torque T Dds The value obtained by subtracting "1 / (1+b1+b2)" and "G -1 " and "1 / (J M ·s+D M )" and "G -1 It is calculated by multiplying " by "1 / (1+b1+b2)".

[0069] Differential mode axle torque T Dds is the differential mode driving side angular velocity ω Dds from the difference mode wheel angular velocity ω DL The value obtained by subtracting "(K s / s)+D s " is calculated by multiplying Difference mode wheel angular velocity ω DL is the differential mode axle torque T Dds Difference mode wheel load side torque T DL The value obtained by subtracting 1 / (J L ·s+D L ) is calculated.

[0070] [C. Driving side equation of motion (sum-difference model)] Regarding the derivation of the above sum model and difference model, the power distribution mechanism 3 may be expressed mathematically as follows using vector representation.

number

[0071] Using the above formula, the equations of motion (sum and difference) for the driving side are formulated for the left and right sides, as follows. Z in the formula 11 is the reduction ratio from the left drive source (left motor 2L) to the left axle (left axle 4L), Z 22 is the reduction ratio from the right drive source (right motor 2R) to the right axle (right axle 4R), Z c is the reduction ratio applied to the shafts on the opposite sides from the left and right drive sources.

[0072]

number

[0073] By applying a matrix to both sides of the above equation to convert to sum-difference mode, we obtain the following equation:

number

[0074] Here, if b1=b2=b, then Z 11 -Z c =Z 22 -Z c =|Z|,Z 11 +Z c =Z 22 +Z c = 1, the formula can be transformed as follows to obtain the equation of motion for motor 2 corresponding to the sum and difference modes. In this way, by decomposing the equation of motion on the drive side into each of the sum and difference modes, the two are decoupled.

[0075]

number

[0076] [D. Equations of motion for wheels and axles (sum and difference model)] Similar to the derivation of the equation of motion on the drive side, the equation of motion for the left and right wheels 5 (load side) and the axle 4 may be expressed mathematically as follows:

number

[0077] Here, the equation of motion of the left and right wheels 5 (load side) is substituted into the equation of motion of the axle 4, and J SM =G 2 J M ,D SM =G 2 D M ,J DM =G 2 (2b+1) 2 J M ,D DM =G 2 (2b+1) 2 D MBy rearranging as above, the following transfer function is obtained:

number

[0078] In addition, the target wheel speed in the sum model (sum mode FF model) and the difference model (difference mode FF model) is expressed as ω SL-ref ,ω DL-ref Then, by properizing the inverse of the above transfer function with a second-order low-pass filter, the following equation can be obtained, which can calculate the axle input torque for the target speed. FF wheel speed control (sum) and FF wheel speed control (difference) can be performed using such an equation. When the following equation is implemented in the format shown in Figure 4, K s =∞,D s =0,D SM =0,D SL =0,D DM =0,D DL =0.

[0079]

number

[0080] [E. Target Speed ​​Calculation Formula] When calculating the target speed of the motor 2, the following equation of motion may be used, which is obtained by simultaneously solving the equation of motion of the axle 4 and the equation of motion of the left and right wheels 5 (load side).

number

[0081] Here, the target wheel speed in the sum model (sum mode FB model) and the difference model (difference mode FB model) is expressed as ω SL-ref ,ω DL-ref and the target driving side angular velocity is ω Sds- ref ,ω Dds-ref Then, the relationship between the target wheel speed and the target drive-side speed can be expressed as follows: Using such an equation, the FB wheel speed control (sum) and the FB wheel speed control (difference) may be performed.

[0082]

number

[0083] [4. Effects] (1) The vehicle control device 10 includes a first calculation unit 21, a second calculation unit 22, a sum mode FB model, a difference mode FB model, and a control unit 24. The first calculation unit 21 calculates a first sum equivalent value corresponding to the sum of a left target speed, which is the target speed of the left drive system or left motor 2L, and a right target speed, which is the target speed of the right drive system or right motor 2R, and calculates a first difference equivalent value corresponding to the difference between the left target speed and the right target speed. Furthermore, the second calculation unit 22 calculates a second sum equivalent value corresponding to the sum of a left actual speed, which is the actual speed of the left drive system or left motor 2L, and a right actual speed, which is the actual speed of the right drive system or right motor 2R, and calculates a second difference equivalent value corresponding to the difference between the left actual speed and the right actual speed.

[0084] The sum mode FB model models the motion states of the left and right drive systems, and the left drive source (left motor 2L) and right drive source (right motor 2R) when the vehicle 1 travels straight. The difference mode FB model models the motion states of the left and right drive systems, and the left drive source (left motor 2L) and right drive source (right motor 2R) when the vehicle 1 turns. The sum mode FB model and the difference mode FB model are stored in, for example, the storage unit 23. By applying the first sum equivalent value and the second sum equivalent value to the sum mode FB model, an FB sum command torque is derived for causing the actual speeds of the drive systems and the motor 2 to follow the target speeds. By applying the first difference equivalent value and the second difference equivalent value to the difference mode FB model, an FB difference command torque is derived for causing the actual speeds of the drive systems and the motor 2 to follow the target speeds. The control unit 24 then controls the torques of the left motor 2L and the right motor 2R using the FB sum command torque and the FB difference command torque.

[0085] In this way, by separating the sum model corresponding to when the vehicle 1 is traveling straight and the difference model corresponding to when it is turning, and applying the first sum equivalent value and the second sum equivalent value and the first difference equivalent value and the second difference equivalent value to each model to derive the FB sum command torque and the FB difference command torque, it is possible to find the command torque that realizes the target speed of the drive train and motor 2 with a simple configuration, and to control the outputs of the left and right motors 2 so that the command torque is obtained. Therefore, it is possible to make the actual speed of the drive train and motor 2 follow the target speed with high precision.

[0086] Furthermore, in a drivetrain that has different characteristics when traveling straight and when turning, the state (behavior) of the drivetrain can be accurately grasped and controlled, and controllability (for example, control accuracy and control response speed) can be improved with a simple configuration, enabling drive force control that can respond to any driving condition. Furthermore, the response characteristics of the vehicle 1 when traveling straight and when turning can be reflected in the outputs of the left and right motors 2, making it easy to achieve the desired motion state.

[0087] (2) In the above embodiment, both the sum mode FB model and the difference mode FB model can be constructed as two-inertia system models. This simple configuration allows for accurate understanding of the motion states of the left and right drivetrains when the vehicle 1 is traveling straight and when turning. Furthermore, control that takes into account viscoelasticity for each of the different characteristics of traveling straight and turning becomes possible. Therefore, the controllability of the vehicle 1 can be improved.

[0088] (3) As shown in Fig. 9(A), the above sum-mode FB model can be expressed as a two-inertia system consisting of a drive-side inertia calculated based on the inertia of the left motor 2L and the right motor 2R, a spring damper designed with stiffness and viscosity, and a load-side inertia calculated based on the body weight of the vehicle 1. Furthermore, the input / output characteristics of this two-inertia system can be expressed by transfer functions such as those shown in [Equation 5], [Equation 16], and [Equation 17]. This makes it possible to accurately grasp the behavior of the drive system when traveling straight ahead, taking viscoelasticity into account, and improve the controllability of the vehicle 1.

[0089] (4) As shown in Fig. 9(B), the above-mentioned difference mode FB model can be expressed as a two-inertia system consisting of a drive-side inertia, which is the equivalent inertia when a torque difference occurs between the left and right wheels and is calculated based on the torque difference amplification factor, a spring damper designed based on stiffness and viscosity, and a load-side inertia calculated based on the yaw inertia of the vehicle 1. In addition, the input / output characteristics of this two-inertia system can be expressed by transfer functions such as those shown in [Equation 8], [Equation 16], and [Equation 17]. This makes it possible to accurately grasp the behavior of the drive system during cornering taking viscoelasticity into account, thereby improving the controllability of the vehicle 1.

[0090] [5. Other] The above-described embodiment is merely illustrative, and does not intend to exclude various modifications or applications of techniques not explicitly stated in the present embodiment. The configurations of the present embodiment can be modified in various ways without departing from the spirit of the present embodiment. Furthermore, the configurations of the present embodiment can be selected or appropriately combined as needed. For example, while the above-described embodiment illustrates a vehicle 1 equipped with a pair of motors 2 as a drive source, an internal combustion engine may be used instead of the motors 2, and the specific type of drive source is not important.

[0091] Furthermore, in the above embodiment, the vehicle 1 is illustrated as having a vehicle drive system (DM-AYC system) including a pair of motors 2 and a power distribution mechanism 3, but the concepts of the sum model and difference model are applicable to any vehicle, including, for example, a vehicle that does not have a power distribution mechanism 3 and an in-wheel motor vehicle. As long as the vehicle has at least a left drive system including a left axle and left wheels to which power from a left drive source is transmitted, and a right drive system including a right axle and right wheels to which power from a right drive source is transmitted, it is possible to implement control similar to that of the above embodiment, and to obtain the same actions and effects as those of the above embodiment.

[0092] Fig. 13 is a block diagram showing the flow of a vehicle control method according to a first modified example. Here, when calculating the second sum equivalent value and the second difference equivalent value applied to the sum mode FF model and the sum mode FB model, the actual speed of the left motor 2L (actual left motor speed) and the actual speed of the right motor 2R (actual right motor speed) are referenced. That is, while the actual speeds of the left and right wheels 5 detected by the wheel speed sensors 18L and 18R are referenced in the example shown in Fig. 4, the actual speeds of the motors 2 detected by the resolvers 17L and 17R are referenced in the first modified example shown in Fig. 13.

[0093] In step A11, the actual speed of motor 2 is converted into wheel speeds (actual speeds of left and right wheels 5) based on the various gear ratios G, b1, b2 associated with the power distribution mechanism 3, and the converted values ​​are introduced into steps A7 and A8. By performing control based on the actual speed of motor 2 in this way, the responsiveness of the actual speed of motor 2 to the target speed can be improved, and the actual speed of the drive system and motor 2 can be made to follow the target speed with higher accuracy.

[0094] Fig. 14 is a graph illustrating the discrepancy between the motor speed and the wheel speed, and Fig. 15 is a block diagram showing the flow of a vehicle control method according to a second modified example. In the drive system of vehicle 1, as shown in Fig. 14, the behavior of the motor speed and the behavior of the wheel speed may diverge. In this case, for example, in steps A9 and A10 of Fig. 4, simply comparing the first sum equivalent value derived from the target wheel speeds of the left and right wheels 5 with the second sum equivalent value derived from the actual speed of the motor 2 may not provide highly accurate feedback.

[0095] Therefore, step A12 shown in Fig. 15 may be added, and the first sum equivalent value and the first difference equivalent value calculated from the target speeds of the left and right wheels 5 may be converted into a first sum equivalent value and a first difference equivalent value of the target speed of the motor 2 using a sum model and a difference model taking viscoelasticity into account, as shown in Figs. 9(A) and (B). Here, the "first sum equivalent value and first difference equivalent value of the target speed of the motor 2 (or the drive system)" are referred to as a "third sum equivalent value and a third difference equivalent value." Step A12 corresponds to a process of converting the first sum equivalent value and the first difference equivalent value into a third sum equivalent value and a third difference equivalent value (a target motor speed calculation process).

[0096] Assuming that the calculation in step A12 is processed by the first calculation unit 21, the first calculation unit 21 converts the first sum equivalent value into a third sum equivalent value equivalent to the sum of the target speed of the left drive source (or left drive system) and the target speed of the right drive source (or right drive system), and converts the first difference equivalent value into a third difference equivalent value equivalent to the difference between the target speed of the left drive source (or left drive system) and the target speed of the right drive source (or right drive system).

[0097] In step A12, the first sum equivalent value obtained in step A1 is converted into a third sum equivalent value, and the first difference equivalent value obtained in step A2 is converted into a third difference equivalent value. For example, the sum mode wheel angular velocity ω SL As a result of applying the sum model, the sum mode drive side angular velocity ω as the third sum equivalent value Sds Further, the difference mode wheel angular velocity ω as the first difference equivalent value is calculated. DL As a result of applying the difference model, the difference mode driver angular velocity ω as the third difference equivalent value Dds is calculated.

[0098] The third sum equivalent value calculated in step A12 is transmitted to step A9. In step A9, an FB sum command torque for reducing the difference between the third sum equivalent value and the second sum equivalent value to zero is obtained. Similarly, the third difference equivalent value calculated in step A12 is transmitted to step A10. In step A10, an FB difference command torque for reducing the difference between the third difference equivalent value and the second difference equivalent value to zero is obtained.

[0099] In this way, by providing step A12 (target motor speed calculation step) prior to step A9 (FB wheel speed control (sum)) and step A10 (FB wheel speed control (difference)), it is possible to calculate the feedback control amount by comparing the speeds of the motors 2, thereby realizing highly responsive and accurate feedback control. Therefore, it is possible to obtain the command torque that realizes the target speed with a simple configuration, and controllability can be improved.

[0100] [6. Notes] The following notes are provided regarding the above-described embodiments and modifications. [Appendix 1] 1. A vehicle control method for controlling outputs of a left drive source and a right drive source in a vehicle having a left drive system including a left axle and left wheels to which power from a left drive source is transmitted, and a right drive system including a right axle and right wheels to which power from a right drive source is transmitted, comprising: a sum mode feedback model that models the motion states of the left and right drive systems, and the left and right drive sources when the vehicle is traveling straight, and a difference mode feedback model that models the motion states of the left and right drive systems, and the left and right drive sources when the vehicle is turning, calculating a first sum equivalent value corresponding to the sum of a left target speed, which is a target speed of the left drive system or the left drive source, and a right target speed, which is a target speed of the right drive system or the right drive source, and calculating a first difference equivalent value corresponding to the difference between the left target speed and the right target speed; calculating a second sum equivalent value corresponding to the sum of a left actual speed, which is the actual speed of the left drive system or the left drive source, and a right actual speed, which is the actual speed of the right drive system or the right drive source, and calculating a second difference equivalent value corresponding to the difference between the left actual speed and the right actual speed; applying the first sum equivalent value and the second sum equivalent value to the sum mode feedback model to obtain a feedback sum command torque for causing the actual speeds of the left drive system and the right drive system or the left drive source and the right drive source to follow their respective target speeds; applying the first sum equivalent value and the second sum equivalent value to the difference mode feedback model to obtain a feedback difference command torque for causing each of the actual speeds to follow each of the target speeds; The torques of the left drive source and the right drive source are controlled using the feedback sum command torque and the feedback difference command torque. A vehicle control method comprising:

[0101] [Appendix 2] The second sum equivalent value and the second difference equivalent value are calculated based on the actual speeds of the left drive source and the right drive source. 2. A vehicle control method according to claim 1,

[0102] [Appendix 3] converting the first sum equivalent value into a third sum equivalent value corresponding to the sum of the target speed of the left drive source or the left drive system and the target speed of the right drive source or the right drive system, and converting the first difference equivalent value into a third difference equivalent value corresponding to the difference between the target speed of the left drive source or the left drive system and the target speed of the right drive source or the right drive system; A feedback control is performed so that the second sum equivalent value and the second difference equivalent value follow the third sum equivalent value and the third difference equivalent value. 3. A vehicle control method according to claim 1 or 2.

[0103] [Appendix 4] a sum-mode feedforward model that models the motion states of the left and right drive systems, and the left and right drive sources when the vehicle is traveling straight, and that derives a feedforward sum command torque for causing the actual speed to follow the target speed by applying the first sum equivalent value; and a difference mode feedforward model that models the motion states of the left drive system, the right drive system, and the left drive source and the right drive source when the vehicle is turning, and that derives a feedforward difference command torque for causing the actual speed to follow the target speed by applying the first difference equivalent value; The torques of the left drive source and the right drive source are controlled using the feedback sum command torque, the feedback difference command torque, the feedforward sum command torque, and the feedforward difference command torque. 4. A vehicle control method according to any one of claims 1 to 3. [Industrial Applicability]

[0104] The present invention is applicable to the vehicle control device manufacturing industry, and also to the vehicle manufacturing industry that mounts the vehicle control device. [Explanation of symbols]

[0105] 1 vehicle 2 Motor (drive source) 3 Power distribution mechanism 4 axles 5 Left and right wheels 6 inverters 7 Battery 10 Vehicle control device 14 Accelerator opening sensor 15 Brake sensor 16 Steering angle sensor 17 Resolver 18 Wheel speed sensor 21 First Calculation Department 22 Second calculation section 23 Memory section 24 Control Unit

Claims

1. 1. A vehicle control device for controlling outputs of a left drive source and a right drive source in a vehicle equipped with a left drive system including a left axle and left wheels to which power from a left drive source is transmitted, and a right drive system including a right axle and right wheels to which power from a right drive source is transmitted, a first calculation unit that calculates a first sum equivalent value that corresponds to the sum of a left target speed that is a target speed of the left drive system or the left drive source and a right target speed that is a target speed of the right drive system or the right drive source, and calculates a first difference equivalent value that corresponds to the difference between the left target speed and the right target speed; a second calculation unit that calculates a second sum equivalent value that corresponds to the sum of a left actual speed that is an actual speed of the left drive system or the left drive source and a right actual speed that is an actual speed of the right drive system or the right drive source, and calculates a second difference equivalent value that corresponds to the difference between the left actual speed and the right actual speed; a sum mode feedback model that models the motion states of the left and right drive systems, and the left and right drive sources when the vehicle is traveling straight, and that derives a feedback sum command torque by applying the first sum equivalent value and the second sum equivalent value to cause the actual speeds of the left and right drive systems or the left and right drive sources to follow their respective target speeds; a difference mode feedback model that models the motion states of the left and right drive systems, and the left and right drive sources when the vehicle is turning, and that derives a feedback difference command torque for causing each actual speed to follow each target speed by applying the first difference equivalent value and the second difference equivalent value; and a control unit that controls the torques of the left drive source and the right drive source using the feedback sum command torque and the feedback difference command torque; A vehicle control device comprising:

2. The second calculation unit calculates the second sum equivalent value and the second difference equivalent value based on the actual speeds of the left drive source and the right drive source.

2. The vehicle control device according to claim 1.

3. the first calculation unit converts the first sum equivalent value into a third sum equivalent value that corresponds to the sum of the target speed of the left drive source or the left drive system and the target speed of the right drive source or the right drive system, and converts the first difference equivalent value into a third difference equivalent value that corresponds to the difference between the target speed of the left drive source or the left drive system and the target speed of the right drive source or the right drive system, The control unit performs feedback control so that the second sum equivalent value and the second difference equivalent value follow the third sum equivalent value and the third difference equivalent value.

2. The vehicle control device according to claim 1.

4. the first calculation unit converts the first sum equivalent value into a third sum equivalent value that corresponds to the sum of the target speed of the left drive source and the target speed of the right drive source, and converts the first difference equivalent value into a third difference equivalent value that corresponds to the difference between the target speed of the left drive source and the target speed of the right drive source, The control unit performs feedback control so that the second sum equivalent value and the second difference equivalent value follow the third sum equivalent value and the third difference equivalent value.

3. The vehicle control device according to claim 2.

5. a sum-mode feedforward model that models the motion states of the left and right drive systems, and the left and right drive sources when the vehicle is traveling straight, and that derives a feedforward sum command torque for causing the actual speed to follow the target speed by applying the first sum equivalent value; and a difference mode feedforward model that models the motion states of the left drive system, the right drive system, and the left drive source and the right drive source when the vehicle is turning, and that derives a feedforward difference command torque for causing the actual speed to follow the target speed by applying the first difference equivalent value; The control unit controls the torques of the left drive source and the right drive source using the feedback sum command torque, the feedback difference command torque, the feedforward sum command torque, and the feedforward difference command torque.

5. The vehicle control device according to claim 1, wherein the vehicle control device is a vehicle control device.

6. 1. A vehicle control method for controlling outputs of a left drive source and a right drive source in a vehicle having a left drive system including a left axle and left wheels to which power from a left drive source is transmitted, and a right drive system including a right axle and right wheels to which power from a right drive source is transmitted, comprising: a sum mode feedback model that models the motion states of the left and right drive systems, and the left and right drive sources when the vehicle is traveling straight, and a difference mode feedback model that models the motion states of the left and right drive systems, and the left and right drive sources when the vehicle is turning, calculating a first sum equivalent value corresponding to the sum of a left target speed, which is a target speed of the left drive system or the left drive source, and a right target speed, which is a target speed of the right drive system or the right drive source, and calculating a first difference equivalent value corresponding to the difference between the left target speed and the right target speed; calculating a second sum equivalent value corresponding to the sum of a left actual speed, which is the actual speed of the left drive system or the left drive source, and a right actual speed, which is the actual speed of the right drive system or the right drive source, and calculating a second difference equivalent value corresponding to the difference between the left actual speed and the right actual speed; applying the first sum equivalent value and the second sum equivalent value to the sum mode feedback model to obtain a feedback sum command torque for causing the actual speeds of the left drive system and the right drive system or the left drive source and the right drive source to follow their respective target speeds; applying the first sum equivalent value and the second sum equivalent value to the difference mode feedback model to obtain a feedback difference command torque for causing each of the actual speeds to follow each of the target speeds; The torques of the left drive source and the right drive source are controlled using the feedback sum command torque and the feedback difference command torque. A vehicle control method comprising:

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