Connected vehicle control device, connected vehicle control method, and connected vehicle control program

Abstract

The present disclosure relates to a control device for a connected vehicle. A trailer is provided with an operation unit (52) mechanically connected to a steered wheel (22), and an actuator (60) for steering the steered wheel. A control device (80) for a connected vehicle is configured so as to execute an acquisition process and a steering control process. The acquisition process is a process for acquiring a vehicle speed and an angle detection value. The angle detection value is a sensor-based detection value that connects a value of an angle variable relating to steering of the vehicle. The steering control process is a process for operating an actuator based on an angle detection value as an input variable and includes a vehicle speed dependent process. The vehicle speed-dependent processing is a process for reducing the responsiveness of the operation amount of the actuator with respect to the change in the angle detection value when the vehicle speed is low than when the vehicle speed is high.

Description

Technical Field

[0001] The present disclosure relates to a control device for a connected vehicle, a control method for a connected vehicle, and a control program for a connected vehicle. Background Art

[0002] For example, Patent Document 1 listed below describes a device for controlling the travel of a coupled vehicle using a traction angle sensor.

[0003] Patent Document 1: U.S. Patent No. 10421490

[0004] However, the sensor that detects the angle associated with the vehicle's steering operation is often overlaid with noise. Furthermore, if the effects of this noise are reflected in the steering control, vibrations can overlap with the steering wheel's control. Therefore, if the steering control unit operated by the driver and the steering wheel are mechanically linked, the control unit generates vibrations that the user can perceive. Summary of the Invention

[0005] A technical solution disclosed herein provides a control device for a coupled vehicle formed by coupling a tractor vehicle and a trailer vehicle. The trailer vehicle includes an operating unit mechanically coupled to a steering wheel, and an actuator for steering the steering wheel. The control device for the coupled vehicle is configured to perform an acquisition process and a steering control process. The acquisition process is a process for acquiring a vehicle speed and an angle detection value. The angle detection value is a sensor-based detection value of an angle variable related to the steering operation of the coupled vehicle. The steering control process is a process for operating an actuator based on the angle detection value as an input variable and includes a vehicle speed-dependent process. The vehicle speed-dependent process is a process for reducing the responsiveness of the actuator's operation amount to a change in the angle detection value when the vehicle speed is low compared to when the vehicle speed is high.

[0006] Another technical solution disclosed in the present invention provides a method for controlling a coupled vehicle formed by coupling a tractor and a trailer. The trailer includes an operating unit mechanically coupled to a steering wheel, and an actuator for steering the steering wheel. The method for controlling the coupled vehicle includes the steps of executing an acquisition process and a steering control process. The acquisition process is a process for acquiring a vehicle speed and an angle detection value. The angle detection value is a sensor-based detection value of an angle variable related to the steering operation of the coupled vehicle. The steering control process is a process for operating an actuator based on the angle detection value as an input variable and includes a vehicle speed-dependent process. The vehicle speed-dependent process is a process for reducing the responsiveness of the actuator's operation amount to a change in the angle detection value when the vehicle speed is low compared to when the vehicle speed is high.

[0007] Another technical solution disclosed in the present invention provides a control program for a coupled vehicle formed by coupling a tractor and a trailer. The trailer includes an operating unit mechanically coupled to a steering wheel, and an actuator for steering the steering wheel. The control program for the coupled vehicle includes instructions for causing a computer to execute an acquisition process and a steering control process. The acquisition process is a process for acquiring a vehicle speed and an angle detection value. The angle detection value is a sensor-based detection value of an angle variable related to the steering operation of the coupled vehicle. The steering control process is a process for operating an actuator based on the angle detection value as an input variable and includes a vehicle speed-dependent process. The vehicle speed-dependent process is a process for reducing the responsiveness of the actuator's operation amount to a change in the angle detection value when the vehicle speed is low compared to when the vehicle speed is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a diagram illustrating the connected vehicles according to the first embodiment.

[0009] Figure 2 It is a block diagram showing the structure of the control system of this embodiment.

[0010] Figure 3 This is a flowchart showing the steps of processing executed by the control device of this embodiment.

[0011] Figure 4 It is a diagram showing a model of a connected vehicle according to this embodiment.

[0012] Figure 5 1 is a time chart illustrating time series data of detection values ​​of the sensor according to this embodiment.

[0013] Figure 6 1 is a diagram showing the relationship between the vehicle speed and the steering speed required for control in this embodiment.

[0014] Figure 7 This is a flowchart showing the procedure of processing executed by the control device of the second embodiment.

[0015] Figure 8 It is a timing chart showing the effect of this embodiment.

[0016] Figure 9 This is a flowchart showing the steps of processing executed by the control device of the fifth embodiment. DETAILED DESCRIPTION

[0017] <First embodiment>

[0018] Hereinafter, a first embodiment will be described with reference to the drawings.

[0019] "Structure connecting vehicles"

[0020] like Figure 1 As shown, the coupled vehicle 10 includes a tractor 20 and a trailer 30. The tractor 20 includes front wheels 22 and rear wheels 24. The front wheels 22 include two wheels, the right front wheel and the left front wheel, and the rear wheels 24 include two wheels, the right rear wheel and the left rear wheel. Figure 1 In FIG, a box-type trailer is exemplified as the trailer 30. The trailer 30 has wheels 32. The wheels 32 include two wheels: a right wheel and a left wheel.

[0021] The trailer 30 is connected to the rear portion 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 as to be rotatable about a shaft 42. The shaft 42 extends in the height direction of the tractor 20.

[0022] Figure 2 A part of the components included in the tractor 20 is shown.

[0023] like Figure 2 As shown, the steering wheel 52 and steering shaft 54 ​​of the steering system 50 provided in the tractor 20 rotate integrally. The steering wheel 52 corresponds to an operating unit mechanically connected to the steering wheel. The rotational power of the steering wheel 52 is converted into steering force for the front wheels 22 via the steering shaft 54 ​​and the rack shaft 56. A steering actuator 60 is mechanically connected to the steering shaft 54. The steering actuator 60 converts the power of a motor 62 into rotational power for the steering shaft 54. The output voltage of an inverter 64 is applied to the terminals of the motor 62.

[0024] Controller 66 controls the torque of motor 62 to control the control variable of front wheels 22, which are the control targets. Here, the control variable is the steering angle. The steering angle is the angle of contact of the tires of front wheels 22. To control the control variable, controller 66 refers to the rotation angle θm of motor 62 detected by rotation angle sensor 68.

[0025] The tractor 20 is equipped with a drive system 70. The drive system 70 includes at least one of an internal combustion engine and a rotating electric machine, which serve as the vehicle's thrust generator. The tractor 20 is equipped with a brake system 72. The brake system 72 includes at least one of a device that decelerates wheel rotation through friction and a device that decelerates wheel rotation by converting wheel power into electrical energy. The device that decelerates wheel rotation by converting power into electrical energy may also be shared with the rotating electric machine of the drive system.

[0026] The tractor 20 is equipped with an ADASECU 80. The ADASECU 80 operates the steering system 50, the drive system 70, and the brake system 72 to control the controlled variables of the connected vehicle 10. These controlled variables include vehicle speed, driving direction, and the tow angle. The tow angle is the angle between the fore-and-aft directions of the tractor 20 and the trailer 30. Furthermore, the drive system 70 may also include a drive control device that controls an internal combustion engine and a rotating electric machine. In this case, "ADASECU 80 operates the drive system 70" means that the ADASECU 80 outputs a command signal to the drive control device. Furthermore, the brake system 72 may also include a brake control device that controls a device that decelerates the rotation of the wheels. In this case, "ADASECU 90 operates the brake system 82" means that the ADASECU 80 outputs a command signal to the brake control device. Furthermore, "ADASECU 80 operates the steering system 50" means that the ADASECU 80 outputs a command signal to the controller 66.

[0027] The ADASECU 80 controls the control variable by referring to the towing angle β detected by the towing angle sensor 90. The towing angle β can have either a positive or negative sign depending on the angle formed by the direction from the rear to the front of the tractor 20 and the direction from the rear to the front of the trailer 30. For example, the sign of the towing angle β can be positive when the direction from the rear to the front of the trailer 30 is offset counterclockwise by less than 180° relative to the direction from the rear to the front of the tractor 20. Furthermore, the ADASECU 80 refers to the wheel speeds ωw1 to ωw4 detected by the wheel speed sensor 92. 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.

[0028] The ADASECU 80 sets the control amount according to the operation state of the user interface 94. The user interface 94 is used to convey the user's intention, such as whether to select automatic driving or manual driving, to the ADASECU 80.

[0029] The ADAS ECU 80 includes a PU 82 and a storage device 84. The PU 82 is a software processing device comprising at least one of a CPU, a GPU, and a TPU. The storage device 84 stores a reverse assist program 84a. The reverse assist program 84a is a program that specifies instructions for the PU 82 to execute reverse assist processing. The reverse assist processing automatically performs steering of the steering wheel during reverse driving of the coupled vehicle 10. The reverse assist program 84a is a program designed to reduce the driver's load during reverse driving.

[0030] That is, during reverse travel of the coupled vehicle 10, even if the steering angle of the tractor 20 remains the same, the behavior of the trailer 30 changes depending on the towing angle β. Therefore, reverse control requires high driver skill. The reverse assist process performed by the reverse assist program 84a assists the driver by controlling the steering angle of the tractor 20. However, the reverse assist process delegates steering instructions for the trailer 30 to the driver.

[0031] "Steering maneuvering in reverse assist"

[0032] Figure 3 Indicates the step of back auxiliary processing. Figure 3 The processing shown is realized by the PU 82 repeatedly executing the back-up assist program 84a at a predetermined cycle, for example. In the following, the step number of each process is expressed by a number with "S" at the beginning.

[0033] exist Figure 3 In the series of processes shown, the PU 82 first determines whether the vehicle is in reverse assist mode (S10). If the PU 82 determines that the vehicle is in reverse assist mode (S10: Yes), it obtains the traction angle β detected by the traction angle sensor 90 (S12). Furthermore, the PU 82 obtains the steering angle α1 detected by the steering system 50 (S14). Specifically, the steering angle α1 is calculated by the controller 66 using the rotation angle θm.

[0034] Then, PU82 takes the steering angle α1 and the traction angle β as input and calculates the virtual steering angle α2 (S16). The virtual steering angle α2 is a variable that represents the direction of travel of the connection between the trailer 30 and the tractor 20. In other words, it represents Figure 1 The variable of the traveling direction of the shaft 42 shown. In this embodiment, as an example, the virtual steering angle α2 is defined by the angle formed by the traveling direction of the ball joint 40 with respect to the front-rear direction of the trailer 30.

[0035] Here, based on Figure 4 The reason for calculating the virtual steering angle α2 based on the steering angle α1 and the traction angle β will be described.

[0036] Figure 4 : shows a model of the connected vehicle 10 used in this embodiment. Figure 4In the model shown, the pair of front wheels 22 of the tractor 20 are considered as one front wheel C0, and the pair of rear wheels 24 of the tractor 20 are considered as one rear wheel B1. In other words, a two-wheel model is used for the tractor 20. In addition, the pair of wheels 32 of the trailer 30 are considered as one wheel B2. The angle formed by the line defined by the front wheel C0 and the connection point C1 and the line defined by the connection point C1 and the wheel B2 is the traction angle β. The connection point C1 is equivalent to Figure 1 The axis 42 is part of the front wheel C0. In addition, the front wheel speed VC0 is a vector moving in the direction of the steering angle α1. The steering angle α1 is quantified as the angle between the moving direction of the front wheel C0 and the line defined by the front wheel C0 and the connection point C1. The direction of the vehicle speed V is parallel to the line defined by the front wheel C0 and the connection point C1. In addition, the direction of the vehicle speed V is parallel to the direction of the vehicle speed V. Figure 4 The angle formed by the line connecting wheel B2 and connection point C1 with the x-direction is angle θ1. Furthermore, the angle formed by the line connecting wheel B2 and connection point C1 with the x-direction is angle θ2. Furthermore, distance l1 is the length between front wheel C0 and rear wheel B1. Furthermore, distance h1 is the length between rear wheel B1 and connection point C1. Distance l2 is the length between connection point C1 and wheel B2.

[0037] Based on the above definition, the direction of velocity VC1 at connection point C1 relative to the direction of travel from wheel B2 toward connection point C1 is virtual steering angle α2. Using the angle γ1 formed by the direction of velocity VC1 at connection point C1 relative to the direction of travel from connection point C1 toward front wheel C0, virtual steering angle α2 is expressed as "-(β - γ1)."

[0038] exist Figure 4 In the model shown, if 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 connection point C1 are used, the following equations (c1) to (c3) are established.

[0039] VC0·cosα1=V…(c1)

[0040] xc0=xb1+l1·cosθ1…(c2)

[0041] xc1=xb1-h1·cosθ1…(c3)

[0042] When the equation obtained by differentiating both sides of the above equations (c2) and (c3) and equation (c1) are used, the following equation (c4) is obtained.

[0043] h1·tanα1+l1·tanγ1=0…(c4)

[0044] According to the above-mentioned 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).

[0045] α2=-β-arctan{(h1 / l1)·tan(α1)}…(c5)

[0046] That is, the virtual steering angle α2 can be obtained from the traction angle β and the steering angle α1.

[0047] Figure 3 The process of S16 shown above may also be a process using the aforementioned equation (c5). Alternatively, by pre-storing mapping data in the storage device 84, the process of S16 may be a process in which the PU 82 performs a mapping operation on the virtual steering angle α2. The mapping data is data that uses the traction angle β and the steering angle α1 as input variables and the virtual steering angle α2 as the output variable.

[0048] Here, mapping data is a set of discrete values ​​of input variables and values ​​of output variables corresponding to the values ​​of the input variables. Furthermore, a mapping operation may be performed such that, when the value of the input variable matches any of the values ​​of the input variables of the mapping data, the value of the corresponding output variable of the mapping data is the result of the operation. Furthermore, a mapping operation may be performed such that, when the value of the input variable does not match any of the values ​​of the input variables of the mapping data, the value obtained by interpolating the values ​​of multiple output variables included in the mapping data is the result of the operation. Alternatively, a mapping operation may be performed such that, when the value of the input variable does not match any of the values ​​of the input variables of the mapping data, the value of the output variable of the mapping data corresponding to the closest value among the values ​​of the multiple input variables included in the mapping data is the result of the operation.

[0049] Return to Figure 3 The PU 82 obtains the target virtual steering angle α2* input to the user interface 94 (S18). The target virtual steering angle α2* is a target value of the virtual steering angle α2. The target virtual steering angle α2* is a variable representing the driver's instruction on the steering of the trailer 30.

[0050] Next, the PU 82 calculates the target steering angle α1*, which is the manipulated variable of feedback control, with the virtual steering angle α2 as the manipulated variable and the target virtual steering angle α2* as the target value of the manipulated variable (S20). Here, the feedback control may, for example, be a process in which the difference between the target virtual steering angle α2* and the virtual steering angle α2 is the input, and the output value of the proportional factor is the target steering angle α1*. Alternatively, for example, the feedback control may be a process in which the value corresponding to the difference between the target virtual steering angle α2* and the virtual steering angle α2 is the input, and the sum of the output values ​​of the proportional factor and the output values ​​of the integral factor is the target steering angle α1*. Alternatively, for example, the feedback control may be a process in which the value corresponding to the difference between the target virtual steering angle α2* and the virtual steering angle α2 is the input, and the sum of the output values ​​of the proportional factor and the output values ​​of the differential factor is the target steering angle α1*. Alternatively, for example, the feedback control may be a process in which the value corresponding to the difference between the target virtual steering angle α2* and the virtual steering angle α2 is the input, and the sum of the output values ​​of the proportional factor, the output value of the differential factor, and the output value of the integral factor is the target steering angle α1*.

[0051] Next, PU82 acquires the vehicle speed V (S22). PU82 calculates the vehicle speed V using at least one of the four wheel speeds ωw1 to ωw4. The processes of S12, S14, and S22 correspond to the acquisition process. Furthermore, the angle detection value corresponds to the traction angle β and the steering angle α1. Then, PU82 calculates a guard value Δα1th for the magnitude of the rate of change of the target steering angle α1* based on the vehicle speed V (S24). Specifically, PU82 variably sets the guard value Δα1th based on the vehicle speed V, with the guard value Δα1th when the vehicle speed V is high being greater than the guard value Δα1th when the vehicle speed V is low. This can also be a process in which PU82 performs a mapping operation on the guard value Δα1th, for example, while the storage device 84 stores mapping data. Here, the mapping data is data that uses the vehicle speed V as an input variable and the guard value Δα1th as an output variable. The mapping data includes mutually different values ​​for the guard value Δα1th.

[0052] Furthermore, in the statement "B is modified according to A under the condition that B when A is larger is equal to B when A is smaller," the situation where A is larger and the situation where A is smaller refer to relative magnitudes when the two are compared. For example, "A is larger" corresponds to "A is a first value," and "A is smaller" corresponds to "A is a second value smaller than the first value." Furthermore, this statement implies that, depending on the setting of the first and second values, B when A is the first value may be larger than B when A is the second value. Furthermore, this statement implies that B is modified according to A so that A when B is larger is larger than A when B is smaller.

[0053] Next, the PU 82 determines whether the absolute value of the difference between the current value "α1*(n)" of the target steering angle α1* and the previous value "α1*(n-1)" is greater than the guard value Δα1th (S26). If the PU 82 determines that the absolute value is greater than the guard value Δα1th (S26: YES), the PU 82 sets the target steering angle α1* to a value that is closest to the value calculated in S20 and whose change from the previous value is equal to the guard value Δα1th (S28). The PU 82 then outputs the target steering angle α1* to the controller 66 (S30). In other words, the PU 82 operates the steering system 50 to bring the steering angle α1 closer to the target steering angle α1*.

[0054] In addition, when the PU82 completes the processing of S30 and the determination is negative in the processing of S10, it temporarily ends the processing. Figure 3 The series of processing shown in FIG. 1 is a series of processing shown in FIG. 1 . In addition, the processing of S16 to S30 corresponds to the steering control processing. In addition, the processing of S24 to S28 corresponds to the vehicle speed dependent processing.

[0055] “Functions and Effects of the Present Embodiment”

[0056] Noise is superimposed on the traction angle β and the steering angle α1 , which are values ​​corresponding to detection values ​​of a sensor that couples an angle variable related to the steering operation of the vehicle 10 .

[0057] Figure 5 represents the time evolution of the traction angle β. Figure 5 As shown, noise is superimposed on the pulling angle β, so the value fluctuates.

[0058] Figure 6 Indicates the speed of the steering operation required for control, that is, the relationship between the steering operation speed and the vehicle speed V. Figure 6 As shown, the steering speed Vd required for control increases as the vehicle speed V increases. This is based on the following reasons.

[0059] That is, according to Figure 4 The time differential of the traction angle β is expressed by the following formula (c6).

[0060] dβ / dt=

[0061] (V / l2)·sinβ

[0062] +{V / (l1·l2)}·{l2+h1·cosβ}·tanα1

[0063] …(c6)

[0064] According to equation (c6), the time differential of the traction angle β is proportional to the vehicle speed V.

[0065] Furthermore, if both sides of the above equation (c5) are differentiated with respect to time, the time differential of the virtual steering angle α2 becomes the sum of the time differential of the trailing angle β and the term including the time differential of the steering angle α1. Therefore, the time differential of the steering angle α1 is considered to be the sum of the term proportional to the time differential of the virtual steering angle α2 and the term proportional to the time differential of the trailing angle. Here, the proportionality factor depends on the steering angle α1. Therefore, according to the above equation (c6), the time differential of the steering angle α1 is also proportional to the vehicle speed V. Furthermore, the term proportional to the time differential of the virtual steering angle α2 is considered to be the sum of the term proportional to the time differential of the steering angle α1 and the term proportional to the time differential of the trailing angle. Therefore, according to the above equation (c6), the time differential of the virtual steering angle α2 is also proportional to the vehicle speed V.

[0066] The steering speed corresponds to the time differential of the steering angle α1, the time differential of the traction angle β, or the time differential of the virtual steering angle α2. Therefore, the greater the vehicle speed V, the greater the steering speed Vd required for control.

[0067] exist Figure 6 The noise NW caused by the detection value of the sensor is also recorded.

[0068] like Figure 6 As shown in FIG, the steering speed Vd required for control is smaller than the noise NW component until the vehicle speed V reaches the threshold value Vth. Figure 6 In the figure, for convenience, the vertical axis is set to speed, but to be more precise, it means that the higher the vertical axis, the higher the frequency.

[0069] like Figure 6 As shown, when vehicle speed V is low, the target steering angle α1* calculated in step S20 may fluctuate excessively rapidly due to the influence of noise on the traction angle β and the steering angle α1. If the target steering angle α1* used for control fluctuates frequently due to the influence of noise, the torque of motor 62 used to control the steering angle α1 to the target steering angle α1* fluctuates frequently. If the torque of motor 62 fluctuates at a high frequency, vibrations may be generated in steering wheel 52.

[0070] Therefore, the PU 52 limits the rate of change of the target steering angle α1* used for control to a protection value Δα1th or less. This prevents rapid or frequent fluctuations in the target steering angle α1* caused by noise in the detected values ​​of the traction angle β and the rotation angle θm. This also reduces vibrations in the steering wheel 52 during extremely low-speed driving with the vehicle 10 coupled.

[0071] <Second embodiment>

[0072] Hereinafter, the second embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

[0073] Figure 7 The following shows the steps of the back-up support process according to this embodiment. Figure 7 The processing shown is realized by PU82 repeatedly executing the back-up auxiliary program 84a at a predetermined cycle. Figure 7 In the Figure 3 For the sake of convenience, the same step numbers are used for corresponding steps shown in the figure.

[0074] exist Figure 7 In the series of processes shown, when PU82 determines that it is the reverse assist mode (S10: Yes), it obtains the vehicle speed V (S22). Then, PU82 sets the cutoff frequency fc of the low-pass filter described later (S40). PU82 sets the cutoff frequency fc according to the vehicle speed V, under the condition that the cutoff frequency fc when the vehicle speed V is low is lower than the cutoff frequency fc when the vehicle speed V is high. This can be achieved, for example, by PU82 performing a mapping operation on the cutoff frequency fc in a state where mapping data is stored in the storage device 84. The mapping data is data in which the vehicle speed V is an input variable and the cutoff frequency fc is an output variable. The mapping data contains different values ​​as the value of the output variable.

[0075] Then, the PU 82 applies filtering processing using a low-pass filter with a cutoff frequency fc to the traction angle β obtained in the process of S12 ( S42 ) and to the steering angle α1 obtained in the process of S14 ( S44 ).

[0076] Then, the PU 82 executes the processes of S16 to S20 and S30. The traction angle β and the steering angle α1 in the process of S16 are values ​​after the low-pass filter process based on the processes of S42 and S44 has been performed.

[0077] When the PU82 completes the process of S30 and makes a negative determination in the process of S10, it temporarily ends the process. Figure 7 The series of processing shown in FIG. 1 . In addition, the processing of S40, S42, S44, S16 to S20, and S30 corresponds to the steering control processing. In addition, the processing of S40, S42, and S44 corresponds to the vehicle speed dependent processing.

[0078] “Functions and Effects of the Present Embodiment”

[0079] PU82 calculates the virtual steering angle α2 using the low-pass filtered traction angle β and steering angle α1. Furthermore, the target steering angle α1* is calculated as the manipulated variable for feedback control, with the virtual steering angle α2 serving as the control variable and the target virtual steering angle α2* serving as the target value of the control variable. Low-pass filtering of the traction angle β and steering angle α1 suppresses the effects of noise. Consequently, significant fluctuations in the virtual steering angle α2 due to noise are suppressed. Consequently, fluctuations in the target steering angle α1* due to noise are suppressed.

[0080] In particular, PU 82 increases the cutoff frequency fc as the vehicle speed V increases. At high vehicle speeds V, the rate of change in steering angle α1 required for control also increases. Therefore, according to this embodiment, a preferred compromise can be achieved between suppressing the effects of noise and improving the responsiveness of control of virtual steering angle α2.

[0081] In particular, even when low-pass filtering cannot accurately determine the stopped state of the connected vehicle 10, the controllability of the virtual steering angle α2 can be improved. Specifically, if the accuracy of the stopped state determination is low, there is a risk of erroneous determination that the connected vehicle 10 is stopped when traveling at an extremely low speed. Furthermore, if stop control is performed while the vehicle is stopped, control of the virtual steering angle α2 cannot be executed.

[0082] exist Figure 8 The left side of FIG shows the changes in the virtual steering angle α2, the traction angle β, the steering angle α1, and the vehicle speed V when the traction angle β and the steering angle α1 are fixed to their values ​​before the stop due to an erroneous determination that the coupled vehicle 10 has stopped. In this case, the PU 82 recognizes that the virtual steering angle α2, the traction angle β, and the steering angle α1 are maintained at their values ​​before the stop determination, and therefore cannot control the virtual steering angle α2.

[0083] On the other hand, Figure 8 The right side of the diagram shows the situation of this embodiment. In this case, the low-pass filtered traction angle β and steering angle α1 change, and thus the virtual steering angle α2 also changes. Therefore, control can be achieved to bring the virtual steering angle α2 closer to the target virtual steering angle α2*.

[0084] <Third embodiment>

[0085] Hereinafter, the third embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

[0086] Figure 9 The following shows the steps of the back-up support process according to this embodiment. Figure 9The processing shown is realized by PU82 repeatedly executing the back-up auxiliary program 84a at a predetermined cycle. Figure 9 In the Figure 3 For the sake of convenience, the same step numbers are used for corresponding steps shown in the figure.

[0087] exist Figure 9 In the series of processing shown, PU82, after completing the processing of S10 and S22, determines whether the vehicle speed V is zero (S50). When PU82 determines that the vehicle speed V is zero (S50: Yes), it substitutes the last value "β(n-1)" for the traction angle β used this time (S12a). In addition, PU82 substitutes the last value "α1(n-1)" for the steering angle α1 used this time (S14a). Then, PU82 executes the processing of S16 to S20 and S30. In addition, the processing of S50 corresponds to the determination processing. In addition, the processing of S12a and S14a corresponds to the maintenance processing.

[0088] When PU82 completes the process of S30, if the determination in the process of S10 is negative, it temporarily ends the process. Figure 9 Incidentally, if the PU82 makes a negative determination in the process of S50, it can execute Figure 3 or Figure 7 The processes of S50, S12a, S14a, S16 to S20, and S30 correspond to the steering control process. The processes of S40, S42, and S44 correspond to the vehicle speed dependent process.

[0089] “Functions and Effects of the Present Embodiment”

[0090] If PU82 determines that the vehicle speed V is zero, it maintains the traction angle β and the steering angle α1 at the values ​​before the vehicle speed V became zero. Therefore, the virtual steering control angle α2 used in the processing of S20 is also maintained at the value before the vehicle speed V became zero. This suppresses the target steering angle α1* from fluctuating due to the influence of noise overlapping with the traction angle β and the steering angle α1 detected each time. Therefore, it is possible to suppress the torque of the motor 62 from fluctuating when the vehicle 10 is connected and stopped. If the torque applied to the steering wheel 52 fluctuates when the vehicle 10 is connected and stopped, the user is particularly likely to feel a sense of discomfort. In contrast, according to this embodiment, such a problem can be suppressed.

[0091] <Other implementation methods>

[0092] In addition, this embodiment can be implemented by modifying as follows: This embodiment and the following modified examples can be implemented in combination with each other within the scope of no technical contradiction.

[0093] About Steering Control Processing

[0094] The steering control process is not limited to a process in which the target steering angle α1* is determined by the feedback control variable, with the virtual steering angle α2 being the control variable and the target virtual steering angle α2* being the target value of the control variable. For example, the steering control process may be a process in which the target steering angle α1* is determined by the sum of the feedback control variable, with the virtual steering angle α2 being the control variable, and the open-loop control variable, with the virtual steering angle α2 being the control variable.

[0095] The steering control process is not limited to one in which the virtual steering angle α2 is the control variable and the target steering angle α1* is the control variable. For example, the steering control process may also be one in which the trailing angle β is the control variable and the target steering angle α1* is the control variable. Here, the PU 82 can set the target value of the trailing angle β based on the target virtual steering angle α2* and the steering angle α1 according to the aforementioned equation (c5).

[0096] For example, the ADAS ECU 80 may output a torque command value for the motor 62. In this case, the PU 82 may set the torque command value for the motor 62 as the manipulated variable of feedback control, with the steering angle α1 being the manipulated variable and the target steering angle α1* being the target value of the manipulated variable. Alternatively, for example, the PU 82 may set the torque command value for the motor 62 as the sum of the manipulated variable of feedback control, with the steering angle α1 being the manipulated variable, and the manipulated variable of open-loop control, with the steering angle α1 being the manipulated variable.

[0097] Regarding vehicle speed dependency

[0098] For example, as described in the column “Regarding Steering Control Processing,” when the ADASECU 80 outputs a command value for the torque of the motor 62 , the vehicle speed-dependent processing may be a processing that reduces the magnitude of the change rate of the command value when the vehicle speed V is low compared to when the vehicle speed is high.

[0099] For example, as described in the column “Regarding Steering Control Processing”, when the operation amount of feedback control with the steering angle α1 as the control amount is set as the torque command value, it is preferable to use the output value of the process of S44 as the steering angle α1 as the feedback control amount.

[0100] · Figure 7 Although the example in which the filtering process is performed on both the traction angle β and the steering angle α1 is shown, the present invention is not limited thereto. For example, the filtering process may be performed on only one of the traction angle β and the steering angle α1.

[0101] "About a sensor that detects the value of an angle variable"

[0102] The sensor for detecting the steering angle is not limited to the rotation angle sensor 68. For example, the sensor for detecting the steering angle may be a steering sensor that detects the rotation angle of the steering shaft 54. Furthermore, for example, the sensor for detecting the steering angle may be a linear position sensor that detects the axial displacement of the rack shaft 56.

[0103] About Actuators

[0104] The actuator is not necessarily the steering actuator 60. The actuator may be a coaxial type actuator in which the rotation axis of the motor 62 is arranged parallel to the rack shaft 56, for example.

[0105] About the Control Device

[0106] · As a control device, it is not limited to having PU82 and storage device 84 to perform software processing. For example, it may also have a dedicated hardware circuit such as ASIC that performs at least a part of the processing performed in the above embodiment. That is, the control device only needs to be a processing circuit with any of the following structures (a) to (c). (a) A processing circuit having a processing device that performs all the above-mentioned processing according to a program, and a program storage device such as a storage device that stores the program. (b) A processing circuit having a processing device that performs a part of the above-mentioned processing according to a program, a program storage device, and a dedicated hardware circuit that performs the remaining processing. (c) A processing circuit having a dedicated hardware circuit that performs all the above-mentioned processing. Here, there may be multiple software execution devices and dedicated hardware circuits that have a processing device and a program storage device.

[0107] About Computers

[0108] The computer is not limited to the PU82 mounted on the vehicle. For example, the PU82 may execute Figure 3 The processes of S10 to S22 and S30 are shown, and the processes of S24 to S28 are executed by the user's portable terminal.

[0109] About the Operations Department

[0110] The operating unit is not limited to the steering wheel 52. For example, a joystick may be used.

[0111] About Vehicles

[0112] · As a connected vehicle, not limited to Figure 1 The vehicle illustrated.

Claims

1. A control device for a coupled vehicle, comprising: a control device for a coupled vehicle formed by coupling a tractor and a trailer; The trailer includes an operating unit mechanically connected to a steering wheel and an actuator for steering the steering wheel. The control device is configured to execute an acquisition process and a steering control process, The acquisition process is a process of acquiring vehicle speed and angle detection values. The angle detection value is a sensor-detected value of an angle variable related to the steering operation of the connected vehicle. The steering control process is a process of operating the actuator based on the angle detection value as an input variable and includes vehicle speed dependent processing. The vehicle speed dependent processing is processing for reducing the responsiveness of the actuator operation amount to a change in the angle detection value when the vehicle speed is low compared to when the vehicle speed is high.

2. The vehicle-connected control device according to claim 1, wherein: The steering control process is a process of operating the actuator according to an operation amount for controlling a predetermined control amount related to the steering operation of the connected vehicle to its target value. The vehicle speed dependency process is a process for limiting the upper limit of the magnitude of the change speed of the operation amount of the actuator to a value smaller when the vehicle speed is low than when the vehicle speed is high.

3. The vehicle-connected control device according to claim 2, wherein: The prescribed control variable is a virtual steering angle, The virtual steering angle is a variable indicating the direction of travel of the connection portion between the trailer and the tractor. The steering control process is a process of operating the actuator according to the operation amount of feedback control using the virtual steering angle as a control amount. The control device is configured to execute a virtual steering angle calculation process, The virtual steering angle calculation process is a process of calculating the virtual steering angle based on the angle detection value as an input variable.

4. The vehicle-connected control device according to claim 2, wherein: The operation amount is a target value of the steering angle of the steering wheel.

5. The vehicle-connected control device according to claim 1, wherein: The steering control process includes a filtering process and operates the actuator according to an output of the filtering process. The filtering process is a process of removing high-frequency components of the angle detection value. The vehicle speed dependent processing is processing for reducing the lower limit value of the frequency component to be removed by the filtering processing when the vehicle speed is low compared to when the vehicle speed is high.

6. The vehicle-connected control device according to claim 1, wherein: The vehicle speed dependent processing includes a determination process and a holding process. The determination process is a process of determining whether the connected vehicle is in a stopped state. The holding process is a process of setting the angle detection value for determining the operation amount of the actuator to a holding state when it is determined that the state is in the stopped state.

7. A method for controlling a coupled vehicle, wherein: The trailer includes an operating unit mechanically connected to a steering wheel and an actuator for steering the steering wheel. The control method includes the steps of executing an acquisition process and executing a steering control process. The acquisition process is a process of acquiring vehicle speed and angle detection values. The angle detection value is a sensor-detected value of an angle variable related to the steering operation of the connected vehicle. The steering control process is a process of operating the actuator based on the angle detection value as an input variable and includes vehicle speed dependent processing. The vehicle speed dependent processing is processing for reducing the responsiveness of the actuator operation amount to a change in the angle detection value when the vehicle speed is low compared to when the vehicle speed is high.

8. A control program for a coupled vehicle, comprising: a control program for a coupled vehicle formed by coupling a tractor and a trailer; The trailer includes an operating unit mechanically connected to a steering wheel and an actuator for steering the steering wheel. The control program has instructions for causing the computer to execute an acquisition process and a steering control process. The acquisition process is a process of acquiring vehicle speed and angle detection values. The angle detection value is a sensor-detected value of an angle variable related to the steering operation of the connected vehicle. The steering control process is a process of operating the actuator based on the angle detection value as an input variable and includes vehicle speed dependent processing. The vehicle speed dependent processing is processing for reducing the responsiveness of the actuator operation amount to a change in the angle detection value when the vehicle speed is low compared to when the vehicle speed is high.

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