Control device for articulated vehicles, control method for articulated vehicles, and control program for articulated vehicles

Abstract

To provide a device for controlling a combination vehicle, which can easily design a controller for feedback-controlling the advancing direction of a connection part of a tractor and a trailer to a target value.SOLUTION: In a deviation calculation process M10, a difference between a virtual steering angle α2 quantifying the advancing direction of a trailer at a hitch point and a target virtual steering angle α2*. A controller M12 substitutes a value obtained by multiplying the difference with a proportional gain Kp for an operation amount v. In coordinate conversion M14, the operation amount v is converted into a target steering angle α1* by using the steering angle α1 of the tractor and a hitch angle β. A combination vehicle which is a plant is controlled in accordance with the target steering angle α1*. The steering angle α1 of the plant is converted into the virtual steering angle α2 on the basis of the hitch angle β in coordinate conversion M16.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a control device for articulated vehicles, a control method for articulated vehicles, and a control program for articulated vehicles. [Background technology]

[0002] Conventionally, there exist articulated vehicles in which a trailer is coupled to a vehicle serving as a tractor. Patent Document 1 proposes a control device that assists in the reverse operation of the articulated vehicle. This control device automatically steers the articulated vehicle so that the trailer moves along a reference path specified by the driver when the driver controls the reverse speed of the vehicle using the accelerator pedal and brake pedal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 9,592,851 Summary of the Invention [Problem to be solved by the invention]

[0004] Articulated vehicles are driven primarily by manipulating the steering angle of the tractor. However, there is a significant nonlinearity between the direction of travel of the trailer and the steering angle. Therefore, controlling the direction of travel of the trailer poses challenges when designing a controller. [Means for solving the problem]

[0005] The means for solving the above problems and their effects will be described below. 1. This invention is applicable to an articulated vehicle including a tractor and a trailer towed by the tractor, and is configured to execute a hitch angle variable acquisition process, a steering angle variable acquisition process, a virtual steering angle variable calculation process, a target virtual steering angle variable acquisition process, and feedback processing, wherein the hitch angle variable acquisition process is a process for acquiring the value of a hitch angle variable, and the hitch angle variable is a variable indicating a hitch angle which is the angle between the front-to-rear direction of the tractor and the front-to-rear direction of the trailer, the steering angle variable acquisition process is a process for acquiring the value of a steering angle variable, and the steering angle variable is a variable indicating the steering angle of the tractor, and the virtual steering angle variable calculation process is a process for calculating the value of a virtual steering angle variable using the value of the hitch angle variable and the value of the steering angle variable as inputs, and the virtual steering angle variable is a variable indicating a target virtual steering angle variable at a connection point between the tractor and the trailer. the target virtual steering angle variable acquisition process is a process for acquiring the value of a target virtual steering angle variable, the target virtual steering angle variable being a variable indicating a target value of the virtual steering angle variable, the feedback process includes an operation amount calculation process, a target steering angle variable calculation process, and an operation process, the operation amount calculation process is a process for calculating an operation amount for feedback control using as input the value of the virtual steering angle variable and the value of the target virtual steering angle variable, the target steering angle variable calculation process is a process for converting the operation amount into the value of a target steering angle variable in accordance with the value of the hitch angle variable and the value of the steering angle variable, the target steering angle variable being a variable indicating a target value of the steering angle, and the operation process is a process for operating the steering angle in accordance with the value of the target steering angle variable.

[0006] In the above configuration, the real plant is the articulated vehicle. In contrast, in the above configuration, a virtual plant is considered in which target steering angle variable calculation processing and steering angle variable calculation processing are added to the real plant. In this case, the virtual plant can be considered to receive the manipulated variable as an input and output its time integral value as a virtual steering angle. Therefore, the relationship between the manipulated variable and the virtual steering angle is a simple linear relationship. Therefore, with the above configuration, the manipulated variable calculation processing can be easily designed. In other words, it is possible to easily design a controller that controls the trailer traveling direction to approach the target value through feedback control.

[0007] 2. In the control device for articulated vehicles described in 1 above, the target steering angle variable calculation process converts the operation amount into a target steering angle variable value in accordance with the hitch angle variable value, the steering angle variable value, and the vehicle speed of the tractor.

[0008] The characteristics of an actual plant depend on the vehicle speed. In contrast, in the above configuration, the vehicle speed is taken into consideration when converting the manipulated variable into the target steering angle, so the vehicle speed dependency of the virtual plant can be suppressed. Therefore, the dependency of the control accuracy of the feedback processing on the vehicle speed can be suppressed.

[0009] 3. The control device for articulated vehicles according to claim 1, further comprising a storage device, wherein the storage device stores map data defining the relationship between the operation amount, the value of the hitch angle variable, the value of the steering angle variable, and the value of the target steering angle variable, and the target steering angle variable calculation process is a process of calculating the value of the target steering angle variable using the map data.

[0010] When the process of converting the operation amount into the target steering angle using the hitch angle variable value and the steering angle variable value is expressed as a formula, the expressed formula is complex. Therefore, when the target steering angle variable calculation process is performed using a formula, the requirements for the specifications of the control device tend to be high. In contrast, in the above configuration, by using map data, the requirements for the specifications of the control device can be suppressed from being high.

[0011] 4. A control device for articulated vehicles as set forth in any one of 1 to 3 above, wherein the articulated vehicles are provided with an interface for a driver to specify the value of the target virtual steering angle variable, and the target virtual steering angle variable acquisition process is a process for acquiring the value of the target virtual steering angle variable in response to an input operation by the driver to the interface.

[0012] In the above configuration, the target virtual steering angle is determined by the driver, so that the demands on the control device can be reduced compared to when the target virtual steering angle is determined by the control device. 5. The control device for articulated vehicles according to any one of 1 to 4 above, wherein the operation amount calculation process includes a proportional controller.

[0013] 6. The control device for articulated vehicles according to 5 above, wherein the gain of the proportional controller is set to a fixed value. 7. A method of controlling an articulated vehicle, comprising the steps of executing each process in the control device for an articulated vehicle as set forth in any one of 1 to 6 above.

[0014] 8. A control program for articulated vehicles that causes a computer to execute each process in the control device for articulated vehicles described in any one of 1 to 6 above. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a configuration of an articulated vehicle according to one embodiment. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control system according to the embodiment. [Figure 3] 3 is a flowchart showing a procedure of a process executed by a control device according to the embodiment. [Figure 4] FIG. 2 is a diagram showing a model of an articulated vehicle according to the embodiment. [Figure 5] FIG. 2 is a block diagram for explaining the effects of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment will be described with reference to the drawings. "Configuration of articulated vehicles" As shown in FIG. 1, the articulated vehicle 10 has a tractor 20 and a trailer 30. FIG. 1 shows an example of the tractor 20 as a pickup truck, which is a type of small freight vehicle. The tractor 20 has front wheels 22 and rear wheels 24. The front wheels 22 include two wheels, a right front wheel and a left front wheel, and the rear wheels 24 include two wheels, a right rear wheel and a left rear wheel. FIG. 1 also shows an example of the trailer 30 as a box-shaped trailer. The trailer 30 has wheels 32. The wheels 32 include two wheels, a right wheel and a left wheel.

[0017] The trailer 30 is connected to the rear of the tractor 20 via a ball joint 40. The ball joint 40 is a member that connects the trailer 30 to the tractor 20 so that the trailer 30 can rotate about an axis 42. The axis 42 extends along the height direction of the tractor 20.

[0018] Figure 2 shows some of the components provided on the tractor 20. As shown in Figure 2, the tractor 20 is equipped with a control device 50. The control device 50 operates a steering system 60, a drive system 62, and a braking system 64 to control the control variables of the articulated vehicle 10, which is the control target. The control variables include vehicle speed, traveling direction, and hitch angle. The hitch angle is the angle between the fore-and-aft direction of the tractor 20 and the fore-and-aft direction of the trailer 30.

[0019] Steering system 60 includes a steering actuator that steers the steered wheels. The steered wheels are, for example, front wheels 22 shown in FIG. 1. Note that steering system 60 may also include a steering control device that operates the steering actuator. In this case, "control device 50 operates steering system 60" means that control device 50 outputs a command signal to the steering control device.

[0020] The drivetrain 62 includes at least one of an internal combustion engine and a rotating electric machine as a thrust generating device for the vehicle. The drivetrain 62 may also include a drive control device that controls the internal combustion engine and the rotating electric machine. In this case, "the control device 50 operates the drivetrain 62" means that the control device 50 outputs a command signal to the drive control device.

[0021] The braking system 64 includes at least one of a device that decelerates the rotation of the wheels by frictional force and a device that decelerates the rotation of the wheels by converting the power of the wheels into electrical energy. The device that decelerates the rotation of the wheels by converting it into electrical energy may be shared with the rotating electric machine of the drive system. The braking system 64 may also include a braking control device that controls the device that decelerates the rotation of the wheels. In this case, "the control device 50 operates the braking system 62" means that the control device 50 outputs a command signal to the braking control device.

[0022] To control the control variable, the control device 50 refers to the steering angle α1 of the steered wheels detected by the steering angle sensor 70. The steering angle α1 is a value in which either the right turn or the left turn has a positive sign and the other has a negative sign. The steering angle α1 is the turning angle of the tires. Note that, for example, if the steering system 60 is equipped with a rack and pinion mechanism, the steering angle sensor 70 may be a sensor that detects the pinion angle. In that case, however, the control device 50 performs a process to convert the pinion angle into the turning angle of the tires. For convenience of explanation, the turning angle of the tires obtained by the above conversion process will be considered to be the detection value of the steering angle sensor 70 below.

[0023] The control device 50 also references the hitch angle β detected by the hitch angle sensor 72. The hitch angle β can be either positive or negative depending on the angle between the direction in which the tractor 20 moves from rear to front and the direction in which the trailer 30 moves from rear to front. For example, the sign of the hitch angle β may be set to positive when the direction in which the trailer 30 moves from rear to front deviates counterclockwise by less than 180 degrees from the direction in which the tractor 20 moves from rear to front. The control device 50 also references the wheel speeds ωw1 to ωw4 detected by the wheel speed sensor 74. The wheel speeds ωw1 and ωw2 are the rotational speeds of the right front wheel 22 and the left front wheel 22, respectively. The wheel speeds ωw3 and ωw4 are the rotational speeds of the right rear wheel 24 and the left rear wheel 24, respectively.

[0024] The control device 50 sets the control amount according to the operation state of the user interface 80. The user interface 80 is used to communicate the user's intentions to the control device 50, such as selecting either manual steering or automatic steering of the combination vehicle 10.

[0025] The control device 50 includes a PU 52 and a storage device 54. The PU 52 is a software processing device including at least one of a CPU, a GPU, a TPU, etc. The storage device 54 stores a reverse assist program 54a.

[0026] The reverse assist program 54a defines commands for executing reverse assist processing. The reverse assist processing is processing that should be executed by the PU 52 to assist in the reverse of the combination vehicle 10. The reverse assist processing is processing that automatically steers the tractor 20. However, in the reverse assist processing, braking and accelerator operation are left to the driver. The reverse assist processing also includes processing for receiving a request to steer the trailer 30. The reverse assist processing then controls the steering angle of the tractor 20 so as to satisfy the steering request of the trailer 30.

[0027] Here, a steering request for the trailer 30 is input by the driver via the user interface 80. The steering request is communicated by specifying a virtual steering angle α2 for the trailer 30. The virtual steering angle α2 refers to the steering angle of the virtual front wheels when the trailer 30 is virtually separated from the tractor 20 and considered as a standalone vehicle with virtual front wheels. The virtual steering angle α2 may be specified, for example, by providing the user interface 80 with a dial that has a positive correlation with the virtual steering angle α2. Here, it is not essential that the rotation angle of the dial and the virtual steering angle α2 are proportional to each other. Note that hereinafter, the virtual steering angle α2 specified by the driver will be referred to as the target virtual steering angle α2*.

[0028] "Reverse assist processing" The procedure for the reverse assist process is shown in Figure 3. The process shown in Figure 3 is realized by the PU 52 repeatedly executing the reverse assist program 54a, for example, at a predetermined interval. Note that, hereinafter, the step numbers of each process are represented by numbers preceded by "S."

[0029] In the series of processes shown in FIG. 3, the PU 52 first determines whether the vehicle is in the reverse assist mode (S10). If the PU 52 determines that the vehicle is in the reverse assist mode (S10: YES), the PU 52 acquires the target virtual steering angle α2* input to the user interface 80 (S12). Next, the PU 52 acquires the steering angle α1 detected by the steering angle sensor 70 (S14). The PU 52 also acquires the hitch angle β detected by the hitch angle sensor 72 (S16). The PU 52 also acquires the vehicle speed VB1 (S17). The vehicle speed VB1 is calculated by the PU 52 according to the wheel speeds ωw3 and ωw4. The vehicle speed VB1 may be, for example, a simple average value of the wheel speeds ωw3 and ωw4.

[0030] Then, the PU 72 uses the vehicle speed VB1, the steering angle α1, and the hitch angle β as inputs to perform map calculations to determine the virtual steering angle α2 (S18). In this embodiment, as an example, the virtual steering angle α2 is defined by the angle between the forward and backward directions of the trailer 30 and the traveling direction of the ball joint 40. Here, the reason for calculating the virtual steering angle α2 from the steering angle α1 and the hitch angle β will be explained with reference to FIG. 4.

[0031] FIG. 4 shows a model of the articulated vehicle 10 used in this embodiment. In the model shown in FIG. 4, the pair of front wheels 22 of the tractor 20 are designated as front wheels C0, and the pair of rear wheels 24 of the tractor 20 are designated as rear wheels B1. That is, a two-wheel model is used for the tractor 20. The pair of wheels 32 of the trailer 30 are designated as wheels B2. The angle between the line defined by the front wheels C0 and hitch point C1 and the line defined by the hitch point C1 and wheel B2 is the hitch angle β. The hitch point C1 corresponds to the axle 42 in FIG. 1. The front wheel speed VC0, which is the speed of the front wheel C0, is a vector that moves in the direction of the steering angle α1. The steering angle α1 is quantified as the angle between the direction of travel of the front wheels C0 and the line defined by the front wheels C0 and hitch point C1. The direction of vehicle speed VB1 is parallel to the line defined by the front wheels C0 and hitch point C1. The angle between the direction of vehicle speed VB1 and the x-direction in Figure 4 is θ1. The angle between the line connecting wheel B2 and hitch point C1 and the x-direction is θ2. Also, the distance l1 between front wheel C0 and rear wheel B1, the distance h1 between rear wheel B1 and hitch point C1, and the distance l2 between hitch point C1 and wheel B2 are defined.

[0032] According to the above definition, the direction of the speed VC1 of the hitch point C1 relative to the direction of travel from wheel B to hitch point C1 is the virtual steering angle α2. If the angle γ1 formed by the direction of the speed VC1 of the hitch point C1 relative to the direction of travel from hitch point C1 to front wheel C0 is used, the virtual steering angle α2 is "-(β-γ1)".

[0033] In the model shown in FIG. 4, the following equations (c1) to (c3) are established using the coordinates (xc0, yc0) of the front wheel C0, the coordinates (xb1, yb1) of the rear wheel B1, and the coordinates (xc1, yc1) of the hitch point C1.

[0034] VC0·cosα1=VB1 …(c1) xc0=xb1+l1·cosθ1 …(c2) xc1=xb1+h1·cosθ1 …(c3) By differentiating both sides of the above equations (c2) and (c3) and using equation (c1), the following equation (c4) is obtained.

[0035] h1·tanα1+l1·tanγ1=0 …(c4) According to the above formula (c4), the angle γ1 can be expressed by the steering angle α1. Therefore, the virtual steering angle α2 is expressed by the following formula (c5).

[0036] α2=-β-arctan{(h1 / l1)·tan(α1)} …(c5) That is, the virtual steering angle α2 can be calculated from the hitch angle β and the steering angle α1. More specifically, in the process of S18, the PU 52 performs map calculation of the virtual steering angle α2 using map data 54b shown in Fig. 2. The map data 54b is stored in the storage device 54. The map data 54b uses the hitch angle β and the steering angle α1 as input variables and the virtual steering angle α2 as an output variable.

[0037] Here, map data refers to a set of data consisting of discrete values ​​of input variables and values ​​of output variables corresponding to each of the input variable values. Furthermore, the map calculation may be a process in which, when the value of an input variable matches one of the input variable values ​​in the map data, the value of the output variable in the corresponding map data is used as the calculation result. Furthermore, when the value of an input variable does not match any of the input variable values ​​in the map data, the map calculation may be a process in which the value obtained by interpolating the values ​​of multiple output variables included in the map data is used as the calculation result. Alternatively, when the value of an input variable does not match any of the input variable values ​​in the map data, the map calculation may be a process in which the value of the output variable in the map data that corresponds to the closest value of the input variable values ​​included in the map data is used as the calculation result.

[0038] The process of S18 can be regarded as a process of converting the steering angle α1 into a virtual steering angle α2 based on the hitch angle β. Next, the PU 52 calculates an operation amount v by feedback control in which the virtual steering angle α2 is used as a control amount and the target virtual steering angle α2* is used as a target value of the control amount (S20). In this embodiment, a proportional controller is used as an example of the feedback controller. That is, the PU 52 multiplies a value obtained by subtracting the virtual steering angle α2 from the target virtual steering angle α2* by a proportional gain Kp, and assigns the result to the operation amount v.

[0039] Then, the PU 72 converts the operation amount v into a target steering angle α1* in accordance with the vehicle speed VB1, the hitch angle β, and the steering angle α1 (S22). Here, this conversion process will be described in detail. In the above model, the first-order time derivative of the hitch angle β is expressed by the following equation (c6).

[0040] dβ / dt= (VB1 / l2)·sinβ +{VB1 / (l1 / l2)}·{l2+h2·cosβ}·tanα1 …(c6) In addition, the first-order time derivative of the steering angle α1 is assumed to be "(α1*-α1)·τ" using the time constant τ.

[0041] In that case, differentiating both sides of the above equation (c5) gives the following equation (c7).

[0042]

number

[0043]

number

[0044] In the process of S22, the operation amount v is converted into the target steering angle α1* in accordance with the coordinate conversion of (c8) above. Specifically, PU 52 performs map calculation of the target steering angle α1* using map data 54b shown in Fig. 2. Here, map data 54b has the operation amount v, vehicle speed VB1, hitch angle β, and steering angle α1 as input variables and the target steering angle α1* as an output variable.

[0045] Then, the PU 52 outputs an operation signal MS to the steering system 60 to control the steering angle of the steered wheels so that the steering angle α1 follows the target steering angle α1* (S24). When the PU 52 completes the process of S24, it temporarily ends the series of processes shown in FIG.

[0046] Here, the operation and effects of this embodiment will be described. As described above, when the first-order time differential value of the virtual steering angle α2 is "v", the time integral value of "v" becomes the virtual steering angle α2. In other words, a simple linear relationship is established between "v" and the virtual steering angle α2.

[0047] Therefore, by utilizing the coordinate transformation according to the above equations (c5) and (c8), a virtual plant is assumed in which the input is "v" and the output is the virtual steering angle α2. FIG. 5 shows an actual plant 90, which is the articulated vehicle 10, and the virtual plant 92 described above.

[0048] As can be seen from the above equation (c5), actual plant 90 does not have a one-to-one correspondence between steering angle α1 and virtual steering angle α2. Therefore, in the process of S20, if the manipulated variable calculated using the difference between target virtual steering angle α2* and virtual steering angle α2 as input is set to target steering angle α1*, it becomes difficult to design a controller that calculates the manipulated variable.

[0049] In contrast, in this embodiment, as shown in Fig. 5, a virtual plant 92 is configured including the coordinate transformation M14 expressed by the above equation (c8) and the coordinate transformation M16 expressed by the above equation (c5). In this case, the relationship between the manipulated variable v and the virtual steering angle α2 is a simple linear relationship. Therefore, it is possible to easily design the controller M12 that calculates the manipulated variable v using as input the difference between the target virtual steering angle α2* calculated by the deviation calculation process M10 and the virtual steering angle α2. That is, in this embodiment, the controller M12 is designed with a proportional gain Kp that is a fixed value.

[0050] <Correspondence> The correspondence between the matters in the above embodiment and the matters described in the "Means for solving the problem" column is as follows. Below, the correspondence is shown for each number of the solving means described in the "Means for solving the problem" column. [1, 2, 7, 8] Hitch angle variable acquisition processing corresponds to the processing of S16. The hitch angle variable corresponds to the hitch angle β. The steering angle variable acquisition processing corresponds to the processing of S14. The steering angle variable corresponds to the steering angle α1. The target virtual steering angle variable acquisition processing corresponds to the processing of S12. The target virtual steering angle variable corresponds to the target virtual steering angle α2*. The virtual steering angle variable calculation processing corresponds to the processing of S18. The virtual steering angle variable corresponds to α2. The feedback processing corresponds to the processing of S20. The target steering angle variable calculation processing corresponds to the processing of S22. The operation processing corresponds to the processing of S24. [3] The storage device corresponds to the storage device 54. [4] The interface corresponds to the user interface 80. [5,6] The process of S20 corresponds to proportional control using proportional gain Kp.

[0051] <Other embodiments> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0052] "About the virtual steering angle variable calculation process" In the above embodiment, the virtual steering angle α2 is calculated using the steering angle α1 and hitch angle β as inputs, but this is not limited to this. For example, the target steering angle α1* may be used instead of the steering angle α1 as the value of the steering angle variable. Furthermore, the value of the hitch angle variable is not limited to the most recent sampled value of the hitch angle β. For example, an estimated hitch angle value predicted from the steering angle α1 and hitch angle β obtained in the previous processing of S14 and S16 may be used.

[0053] It is not essential to calculate the virtual steering angle α2 using a map. For example, it may be calculated using the above formula (c5). "Regarding the target steering angle variable calculation process" In the above embodiment, the target steering angle α1* is calculated using the operation amount v, vehicle speed VB1, steering angle α1, and hitch angle β as inputs, but this is not a limitation. For example, the target steering angle α1* calculated in the previous processing of S22 may be used instead of the steering angle α1 as the value of the steering angle variable. Furthermore, the value of the hitch angle variable is not limited to the most recent sampled value of the hitch angle β. For example, an estimated value of the hitch angle predicted from the steering angle α and hitch angle β obtained in the previous processing of S14 and S16 may be used. Furthermore, for example, in cases where the possible values ​​of the vehicle speed VB1 are somewhat limited, such as in the reverse assist processing, the vehicle speed VB1 may be a preset fixed value instead of a value detected by a sensor. In other words, it is not necessary to use the vehicle speed VB1 as an input.

[0054] It is not essential to calculate the target steering angle α1* using a map. For example, it may be calculated using the above formula (c8). "Operation volume calculation process" The manipulated variable calculation process does not necessarily have to be a process in which the output value of a proportional element having the difference between the target virtual steering angle α2* and the virtual steering angle α2 as input is used as the manipulated variable v. For example, the process may be a process in which the sum of the output value of a proportional element having the difference as input and the output value of an integral element is used as the manipulated variable v. Alternatively, for example, the process may be a process in which the sum of the output value of a proportional element having the difference as input and the output value of a derivative element is used as the manipulated variable v. Alternatively, for example, the process may be a process in which the sum of the output value of a proportional element having the difference as input and the output value of an integral element having the difference as input and the output value of a derivative element is used as the manipulated variable v.

[0055] "About reverse assist processing" The reverse assist process does not necessarily have to be a process in which accelerator and brake operations are left to the driver. For example, the reverse assist process may be a process in which the speed of the tractor 20 is automatically controlled.

[0056] "Feedback processing and operation processing" It is not essential that the feedback processing be performed during the reverse assist processing. For example, the control device 50 may perform the above feedback processing and operation processing during the automatic steering processing in which the target virtual steering angle α2* is set. Furthermore, it is not essential that the automatic steering processing be processing performed when the combination vehicle 10 is moved backward. In other words, the above feedback processing and operation processing may be performed during the automatic steering processing when the combination vehicle is moved forward.

[0057] About Input Variables Although the hitch angle β, the steering angle α1, etc. are used as input variables for the above processes, they are not limited to these. For example, the above-mentioned pinion angle itself may be used instead of the steering angle α1.

[0058] "About the control device" The control device is not limited to one equipped with a PU 52 and a storage device 54 and executing software processing. For example, it may be equipped with a dedicated hardware circuit, such as an ASIC, that performs hardware processing on at least a portion of what was software processed in the above embodiments. That is, the control device may have any of the following configurations (a) to (c): (a) equipped with a processing device that executes all of the above processing according to a program, and a program storage device, such as a storage device, that stores the program; (b) equipped with a processing device and program storage device that executes part of the above processing according to a program, and a dedicated hardware circuit that executes the remaining processing; or (c) equipped with a dedicated hardware circuit that executes all of the above processing. Here, there may be multiple software execution devices equipped with a processing device and a program storage device, and multiple dedicated hardware circuits.

[0059] "About Computers" The computer that executes control programs such as the reverse assist program 54a is not limited to a computer mounted on the combination vehicle 10. For example, the computer may be configured by both the PU 52 mounted on the combination vehicle 10 and a mobile terminal of the driver. In that case, for example, the processing of S18 to S22 may be executed by the mobile terminal.

[0060] "About the vehicle" The articulated vehicles are not limited to the vehicles shown in FIG. [Explanation of symbols]

[0061] 10...Articulated vehicle 20...Tractor 22...Front wheel 24...Rear wheel 30...Trailer 32...Wheel 40...ball joint 42...Axis 50...Control device

Claims

1. The present invention is applied to a combination vehicle including a tractor and a trailer towed by the tractor, configured to execute a hitch angle variable acquisition process, a steering angle variable acquisition process, a virtual steering angle variable calculation process, a target virtual steering angle variable acquisition process, and a feedback process; The hitch angle variable acquisition process is a process for acquiring a value of a hitch angle variable, the hitch angle variable is a variable indicating a hitch angle, which is an angle between the front-rear direction of the tractor and the front-rear direction of the trailer, the steering angle variable acquisition process is a process for acquiring a value of a steering angle variable, the steering angle variable is a variable indicating a steering angle of the tractor, the virtual steering angle variable calculation process is a process of calculating a value of a virtual steering angle variable using a value of the hitch angle variable and a value of the steering angle variable as inputs, the virtual steering angle variable is a variable indicating a traveling direction at a connection point between the tractor and the trailer, the target virtual steering angle variable acquisition process is a process for acquiring a value of a target virtual steering angle variable, the target virtual steering angle variable is a variable indicating a target value of the virtual steering angle variable, the feedback processing includes an operation amount calculation processing, a target steering angle variable calculation processing, and an operation processing, the operation amount calculation process is a process of calculating an operation amount for feedback control using the value of the virtual steering angle variable and the value of the target virtual steering angle variable as inputs, the target steering angle variable calculation process is a process of converting the operation amount into a target steering angle variable value in accordance with the hitch angle variable value and the steering angle variable value, the target steering angle variable is a variable indicating a target value of the steering angle, The control device for articulated vehicles, wherein the operation processing is processing for operating the steering angle in accordance with the value of the target steering angle variable.

2. 2. The control device for articulated vehicles according to claim 1, wherein the target steering angle variable calculation process converts the operation amount into the value of the target steering angle variable in accordance with the hitch angle variable value, the steering angle variable value, and the vehicle speed of the tractor.

3. a storage device; the storage device stores map data defining a relationship between the operation amount, the hitch angle variable value, the steering angle variable value, and the target steering angle variable value; 2. The control device for an articulated vehicle according to claim 1, wherein the target steering angle variable calculation process calculates the value of the target steering angle variable using the map data.

4. the combination vehicle includes an interface for a driver to specify a value of the target virtual steering angle variable; 2. The control device for articulated vehicles according to claim 1, wherein the target virtual steering angle variable acquisition process acquires the value of the target virtual steering angle variable in response to an input operation by the driver to the interface.

5. The control device for articulated vehicles according to claim 1 , wherein the operation amount calculation process includes a proportional controller.

6. 6. A control device for an articulated vehicle according to claim 5, wherein the gain of said proportional controller is set to a fixed value.

7. A method for controlling an articulated vehicle, comprising the steps of executing each process in the control device for an articulated vehicle according to claim 1.

8. A control program for articulated vehicles that causes a computer to execute each process in the control device for articulated vehicles according to claim 1.

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