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

Abstract

The connected vehicle is provided with a tractor and a trailer towed by the tractor. A computing device (50) of a connected vehicle is configured to execute curvature variable acquisition processing, trailer length variable acquisition processing, and virtual steering angle calculation processing. The curvature variable acquisition process is a process for acquiring a value of a curvature variable. The curvature variable is a variable indicating the curvature of the travel trajectory of the trailer. The trailer length variable acquisition processing is processing for acquiring the value of the trailer length variable. The trailer length variable is a variable indicating the length of the trailer. The virtual steering angle calculation process is a process for calculating a virtual steering angle (alpha2) using the value of the curvature variable and the value of the trailer length variable as inputs. The virtual steering angle (alpha2) is an angle indicating a displacement direction of a connection portion between the trailer and the towing vehicle.

Description

Technical Field

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

[0002] For example, Patent Document 1 below describes a control device that performs reverse assist control for a trailer. This control device estimates a hitch angle using the yaw rate of the trailer and the yaw rate of the towing vehicle. Then, reverse assist control is performed using the estimated hitch angle.

[0003] Patent Document 1: U.S. Patent No. 9,340,228 Specification

[0004] The above control device uses the yaw rate of the towing vehicle in the calculation of variables used for the travel control of the trailer. However, for example, when the trailer is displaced while the towing vehicle is stopped due to a curb, there is a concern that the yaw rate of the towing vehicle is not suitable as a value used in the calculation of variables used for the travel control of the trailer. Summary of the Invention

[0005] In one aspect of the present disclosure, there is provided an arithmetic device for a coupled vehicle. The coupled vehicle includes a towing vehicle and a trailer towed by the towing vehicle. The arithmetic device for the coupled vehicle is configured to execute a curvature variable acquisition process, a trailer length variable acquisition process, and a virtual steering angle calculation process. The curvature variable acquisition process is a process of acquiring a value of a curvature variable. The curvature variable is a variable representing the curvature of the travel trajectory of the trailer. The trailer length variable acquisition process is a process of acquiring a value of a trailer length variable. The trailer length variable is a variable representing the length of the trailer. The virtual steering angle calculation process is a process of calculating a virtual steering angle using the value of the curvature variable and the value of the trailer length variable as inputs. The virtual steering angle is an angle representing the displacement direction of the connection portion between the trailer and the towing vehicle.

[0006] In other aspects of the present disclosure, a control method for a coupled vehicle is provided. The coupled vehicle includes a towing vehicle and a trailer towed by the towing vehicle. The control method for the coupled vehicle is a method that executes a curvature variable acquisition process, a trailer length variable acquisition process, and a virtual steering angle calculation process. The curvature variable acquisition process is a process of acquiring the value of a curvature variable. The curvature variable is a variable representing the curvature of the traveling trajectory of the trailer. The trailer length variable acquisition process is a process of acquiring the value of a trailer length variable. The trailer length variable is a variable representing the length of the trailer. The virtual steering angle calculation process is a process of calculating a virtual steering angle by using the value of the curvature variable and the value of the trailer length variable as inputs. The virtual steering angle is an angle representing the displacement direction of the connection portion between the trailer and the towing vehicle.

[0007] In other aspects of the present disclosure, a control program for a coupled vehicle is provided. The coupled vehicle includes a towing vehicle and a trailer towed by the towing vehicle. The control program for the coupled vehicle causes a computer to execute a curvature variable acquisition process, a trailer length variable acquisition process, and a virtual steering angle calculation process. The curvature variable acquisition process is a process of acquiring the value of a curvature variable. The curvature variable is a variable representing the curvature of the traveling trajectory of the trailer. The trailer length variable acquisition process is a process of acquiring the value of a trailer length variable. The trailer length variable is a variable representing the length of the trailer. The virtual steering angle calculation process is a process of calculating a virtual steering angle by using the value of the curvature variable and the value of the trailer length variable as inputs. The virtual steering angle is an angle representing the displacement direction of the connection portion between the trailer and the towing vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective view showing the configuration of a coupled vehicle according to the first embodiment.

[0009] Figure 2 is a block diagram showing the configuration of the control system according to the above embodiment.

[0010] Figure 3 is a flowchart showing the order of processes executed by the control device according to the above embodiment.

[0011] Figure 4 is a flowchart showing the order of processes executed by the control device according to the above embodiment.

[0012] Figure 5 is a flowchart showing the order of processes executed by the control device according to the above embodiment.

[0013] Figure 6A and Figure 6BThis is a diagram showing the effects of the above-described embodiment.

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

[0015] Figure 8 This is a flowchart showing the order of processing executed by the control device according to the third embodiment.

[0016] Figure 9 This is a diagram showing the model used for calculating the towing angle in the above-described embodiment. Detailed Embodiments

[0017] <First Embodiment>

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

[0019] "Configuration of a connected vehicle"

[0020] As Figure 1 shown, the connected vehicle 10 includes a towing vehicle 20 and a trailer 30. In Figure 1 , as the towing vehicle 20, a pickup truck, which is a type of minivan, is exemplified. The towing vehicle 20 includes 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. Further, in Figure 1 , 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 of the towing vehicle 20 via a ball joint 40. The ball joint 40 is a component that connects the trailer 30 to the towing vehicle 20 so as to be rotatable about an axis 42. The axis 42 extends along the height direction of the towing vehicle 20.

[0022] In Figure 2 a part of the components included in the connected vehicle 10 is shown. As Figure 2 shown, the connected vehicle 10 includes a control device 50. Specifically, the towing vehicle 20 includes the control device 50. The control device 50 operates the steering system 60, the drive system 62, and the braking system 64 of the towing vehicle 20 in order to control the control amount of the connected vehicle 10 that is the control object. The control amount includes vehicle speed, traveling direction, and towing angle, etc. The towing angle is the angle formed between the front-rear direction of the towing vehicle 20 and the front-rear direction of the trailer 30.

[0023] The steering system 60 includes a steering actuator that steers the steering wheels of the towing vehicle 20. The steering wheels are, for example, Figure 1The front wheel 22 shown. In addition, the steering system 60 may also include a steering control device that operates the steering actuator. In this case, "the control device 50 operates the steering system 60" means that the control device 50 outputs a command signal to the steering control device.

[0024] The drive system 62 includes at least one of an internal combustion engine and a rotary electric machine as a thrust generation device of the vehicle. In addition, a drive control device that controls the internal combustion engine and the rotary electric machine may also be included in the drive system 62. In this case, "the control device 50 operates the drive system 62" means that the control device 50 outputs a command signal to the drive control device.

[0025] The braking system 64 includes at least one of a device that decelerates the rotation of the wheels of the towing vehicle 20 by frictional force and a device that decelerates the rotation of the wheels of the towing vehicle 20 by converting the power of the wheels into electric energy. In addition, the device that decelerates the rotation of the wheels of the towing vehicle 20 by converting into electric energy may also be shared with the rotary electric machine of the drive system. In addition, a braking control device that controls the device that decelerates the rotation of the wheels may also be included in the braking system 64. 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.

[0026] The control device 50 refers to the steering angle α1 of the steering wheel of the towing vehicle 20 detected by the steering angle sensor 70 in order to control the control amount. The steering angle α1 is a value with a positive sign corresponding to either right turn or left turn and a negative sign corresponding to the other. The steering angle α1 is the side slip angle of the tire. In addition, the control device 50 refers to the yaw rate yr of the trailer 30 detected by the yaw rate sensor 72. In addition, when the user appropriately selects and uses the trailer 30 connected to the towing vehicle 20 from among a plurality of trailers 30, the yaw rate sensor 72 provided in the used trailer 30 is connected to the electronic components of the towing vehicle 20. In addition, the control device 50 refers to the wheel speeds ωwr and ωwl of the trailer 30 detected by the wheel speed sensor 74. The wheel speeds ωwr and ωwl are the rotational speeds of the right wheel 32 and the left wheel 32, respectively. In addition, when the user appropriately selects and uses the trailer 30 connected to the towing vehicle 20 from among a plurality of trailers 30, the wheel speed sensor 74 provided in the used trailer 30 is connected to the electronic components of the towing vehicle 20.

[0027] The control device 50 sets the control of the control amount according to the operation state of the user interface 80. The user interface 80 has a function of transmitting the user's intention, such as selecting either manual steering or automatic steering of the coupled vehicle 10, to the control device 50.

[0028] 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, and a TPU. A reverse assist program 54a is stored in the storage device 54.

[0029] The reverse assist program 54a defines an instruction for executing reverse assist processing. The reverse assist processing is processing that should be executed by the PU 52 in terms of assisting the reverse of the connected vehicle 10. The reverse assist processing is processing for automatically steering the tow vehicle 20. However, in the reverse assist processing, the brake operation and the accelerator operation are entrusted to the driver. In addition, in the reverse assist processing, it includes processing for receiving a request for steering the trailer 30. Moreover, in the reverse assist processing, the steering angle of the tow vehicle 20 is controlled to satisfy the request for steering the trailer 30.

[0030] Here, a request for steering the trailer 30 is input by the driver via the user interface 80. The request for steering is conveyed by indicating the virtual steering angle α2 of the trailer 30. The virtual steering angle α2 is an angle indicating the displacement direction of the trailer 30 at the connection part between the trailer 30 and the tow vehicle 20. In other words, the virtual steering angle α2 is an angle indicating the displacement direction of the shaft 42. For example, the indication of the virtual steering angle α2 can also be realized by setting a dial having a positive correlation with the virtual steering angle α2 on the user interface 80. Here, the rotation angle of the dial does not necessarily have a proportional relationship with the virtual steering angle α2. In addition, hereinafter, the virtual steering angle α2 indicated by the driver is referred to as the target virtual steering angle α2*.

[0031] The reverse assist processing is executed using the virtual steering angle α2 estimated based on the detection value of the sensor. Hereinafter, the various pre-processings for the estimation of the virtual steering angle α2 and the order of the reverse assist processing will be described.

[0032] "Obtaining the trailer length"

[0033] In Figure 3 The sequence of processing for obtaining the trailer length Lt is shown. The trailer length Lt is the length of the line connecting the center of the line segment connecting the respective rotation centers of the two wheels 32 to the shaft 42. This is achieved by the PU 52 repeatedly executing the reverse assist program 54a at a prescribed period, for example. Figure 3 As shown in. In addition, hereinafter, the step numbers of each processing are represented by numbers with "S" appended to the front.

[0034] In Figure 3In the series of processes shown, PU52 first determines whether the trailer length Lt has been acquired (S10). For example, when the trailer length Lt is stored in a specified storage area of the storage device 54, PU52 determines that the trailer length Lt has been acquired. However, when the trailer 30 connected to the towing vehicle 20 is changed, it is preferable that the user operates the user interface 80 to notify the main idea. In this case, when the trailer length Lt is stored in the specified storage area, PU52 can simply temporarily delete the trailer length Lt.

[0035] When PU52 determines that the trailer length Lt has not been acquired yet (S10: No), it displays visual information prompting the user to input the trailer length Lt on the display device 82 by operation (S12). Then, PU52 stands by (S14: No) until the trailer length Lt is input by operating the user interface 80. When PU52 determines that the trailer length Lt has been input (S14: Yes), it stores the trailer length Lt in a specified storage area of the storage device 54 (S16).

[0036] In addition, when a positive determination is made in the process of S10 and when the process of S16 is completed, PU52 temporarily ends Figure 3 the series of processes shown.

[0037] "Calculation of the virtual steering angle α2"

[0038] In Figure 4 FIG. shows the sequence of processes related to the calculation of the virtual steering angle α2. This is achieved by PU52 repeatedly executing the reverse assist program 54a, for example, at a specified cycle Figure 4 the series of processes shown.

[0039] In Figure 4 the series of processes shown, PU52 first acquires the yaw rate yr of the trailer 30 and the vehicle speed V of the trailer 30 (S20). PU52 calculates the vehicle speed V of the trailer 30 based on at least one of the wheel speeds ωwr and ωwl. The vehicle speed V can be, for example, the average value of the wheel speeds ωwr and ωwl. Next, PU52 substitutes the value obtained by dividing the yaw rate yr by the vehicle speed V into the curvature ktr (S22). Then PU52 reads out the trailer length Lt stored in the above-mentioned specified storage area (S24). Then PU52 substitutes the value obtained by multiplying the value of the dependent variable of the arctangent function with the product of the trailer length Lt and the curvature ktr as the independent variable by "-1" into the virtual steering angle α2 (S26).

[0040] In addition, when the process of S26 is completed, PU54 temporarily ends Figure 4 the series of processes shown.

[0041] "Reverse assist process"

[0042] Figure 5 Shows the sequence of reverse assist processing. It is implemented by repeatedly executing the reverse assist program 54a by the PU52, for example, at a prescribed period. Figure 5 The series of processes shown.

[0043] In Figure 5 In the series of processes shown, the PU52 first determines whether it is in the reverse assist mode (S30). When the PU52 determines that it is in the reverse assist mode (S30: Yes), it acquires the target virtual steering angle α2* (S32). Then, the PU52 substitutes the operation amount of the control in which the virtual steering angle α2 calculated in the Figure 4 process is the control amount and the target virtual steering angle α2* is the target value of the control amount into the target steering angle α1* (S34). This operation amount may be the operation amount of feedback control. Additionally, for example, this operation amount may also be the sum of the operation amount of feedback control and the operation amount of open-loop control.

[0044] Next, the PU52 acquires the steering angle α1 (S36). Then, the PU52 calculates the operation amount of the control in which the steering angle α1 is the control amount and the target steering angle α1* is the target value of the control amount (S38). This operation amount may be the operation amount of feedback control. Additionally, for example, this operation amount may also be the sum of the operation amount of feedback control and the operation amount of open-loop control. This operation amount may also be, for example, the torque of the motor of the steering system 60.

[0045] Then, the PU52 operates the steering system 60 according to the operation amount (S40).

[0046] In addition, when the PU52 finishes the process of S40 and when a negative determination is made in the process of S30, it temporarily ends Figure 5 the series of processes shown.

[0047] "Functions and effects of the present embodiment"

[0048] The PU52 calculates the curvature ktr of the traveling trajectory of the trailer 30 based on the yaw rate yr of the trailer 30 and the vehicle speed V of the trailer 30 as input variables. The PU52 calculates the virtual steering angle α2 based on the curvature ktr of the traveling trajectory of the trailer 30 as input. The PU52 controls the virtual steering angle α2 to be close to the target virtual steering angle α2*.

[0049] Thus, in the present embodiment, it is possible to perform the travel control of the trailer 30 without using the detected value of the yaw rate of the towing vehicle 20. Even when the towing vehicle 20 stops and only the trailer 30 is displaced, for example, the virtual steering angle α2 can be calculated with high precision without using the detected value of the yaw rate of the towing vehicle 20. Further, by using the virtual steering angle α2 as the manipulated variable for feedback control, the travel of the trailer 30 can be controlled with high precision.

[0050] According to the present embodiment described above, the following functions and effects can be further obtained.

[0051] (1-1) The virtual steering angle α2 is calculated using the actual curvature ktr obtained from the travel of the trailer 30. Thus, the virtual steering angle α2 can be calculated with higher precision than in the case of calculating the virtual steering angle α2 using the model of the coupled vehicle 10.

[0052] In Figure 6A and Figure 6B , the travel control of the trailer 30 using the virtual steering angle α2 according to the present embodiment is shown by a solid line. Further, in Figure 6A and Figure 6B , the travel control of the trailer 30 using the virtual steering angle α2 calculated by the model method, that is, the comparative example, is shown by a dashed line.

[0053] Specifically, Figure 6A shows the travel trajectory of the trailer 30. In Figure 6A , the vertical axis is the y-axis of the plane coordinate system, and the horizontal axis is the x-axis of the plane coordinate system. As Figure 6A shows, a difference in the curvature based on the travel of the trailer 30 occurs between the case of the present embodiment and the comparative example. This is because a model error occurs in the case of the model method. In contrast, in the case of the present embodiment, since the virtual steering angle α2 calculated based on the actual curvature of the trailer 30 is used as the control variable, the trajectory of the trailer 30 can be controlled with high precision.

[0054] Figure 6B shows the change in the drawbar angle. As Figure 6B shows, a stable deviation occurs in the change in the drawbar angle between the present embodiment and the comparative example. This difference is due to the model error of the comparative example.

[0055] (1-2) When the PU52 does not acquire the trailer length Lt, it prompts the user for an input of the trailer length Lt. Thus, the trailer length Lt can be acquired.

[0056] <Second Embodiment>

[0057] Hereinafter, the second embodiment will be described with reference to the drawings, centering on the differences from the first embodiment.

[0058] In Figure 7 FIG. shows the sequence of processes related to the calculation of the virtual steering operation angle α2 according to the present embodiment. This is achieved by repeatedly executing the reverse assist program 54a, for example, at a predetermined cycle by the PU52 Figure 7 shown series of processes. Further, in Figure 7 , for convenience, the same step numbers are attached to the processes corresponding to the Figure 4 shown processes.

[0059] In Figure 7 the series of processes shown, the PU52 first acquires the wheel speeds ωwr and ωwl (S20a). Next, the PU52 substitutes the value obtained by dividing the value obtained by subtracting the wheel speed ωwl from the wheel speed ωwr by the wheelbase d into the curvature ktr (S22a). The wheelbase d is the distance between the rotation centers of the two wheels 32 of the trailer 30.

[0060] Then, the PU52 executes the processes of S24 and S26 and temporarily ends the Figure 7 shown series of processes.

[0061] <Third Embodiment>

[0062] Hereinafter, the third embodiment will be described with reference to the drawings, centering on the differences from the first embodiment.

[0063] In the present embodiment, when the possibility of a jack-knife phenomenon increases, a process for warning the main idea thereof is executed. The jack-knife phenomenon is a phenomenon in which the trailer 30 cannot be steered due to an excessive increase in the magnitude of the towing angle.

[0064] In Figure 8 FIG. shows the sequence of processes related to the above warning. This is achieved by repeatedly executing the reverse assist program 54a, for example, at a predetermined cycle by the PU52 Figure 8 shown series of processes.

[0065] In Figure 8 the series of processes shown, the PU52 first determines whether it is in the reverse assist mode (S50). When the PU52 determines that it is in the reverse assist mode (S50: Yes), it acquires the steering angle α1 and the virtual steering operation angle α2 (S52). Then, the PU52 calculates the towing angle β using the following equation (c1) (S54).

[0066] β = -α2 - arctan{(h1 / l1) · tan(α1)}…(c1)

[0067] The above formula (c1) is a formula based on the models of the tractor 20 and the trailer 30.

[0068] In Figure 9 shows the above models. In Figure 9 In the shown model, a pair of front wheels 22 of the tractor 20 correspond to the front wheels C0, and a pair of rear wheels 24 of the tractor 20 correspond to the rear wheels B1. That is, a two-wheel model is adopted for the tractor 20. In addition, a pair of wheels 32 of the trailer 30 correspond to the wheels B2. The angle formed by the line defined by the front wheels C0 and the towing point C1 and the line defined by the towing point C1 and the wheels B2 is the towing angle β. The towing point C1 corresponds to Figure 1 the axis 42. In addition, the speed of the front wheels C0, that is, the front wheel speed VC0, is a vector quantity advancing in the direction of the steering angle α1. The steering angle α1 is quantified as the angle formed by the advancing direction of the front wheels C0 and the line defined by the front wheels C0 and the towing point C1. The direction of the vehicle speed Vtra of the tractor 20 is parallel to the line defined by the front wheels C0 and the towing point C1. In addition, the angle formed by the direction of the vehicle speed Vtra and Figure 4 the x-direction of

[0069] is the angle θ1. In addition, the distance l1 is the length between the front wheels C0 and the rear wheels B1. In addition, the distance h1 is the length between the rear wheels B1 and the towing point C1. Figure 9 In addition, in

[0070] In the present embodiment, the direction of the speed VC1 of the towing point C1 with respect to the direction advancing from the wheels B2 to the towing point C1 becomes the virtual steering angle α2. Therefore, if the angle γ1 formed by the direction of the speed VC1 of the towing point C1 with respect to the direction advancing from the towing point C1 to the front wheels C0 is used, the virtual steering angle α2 is "-(β - γ1)".

[0071] In Figure 9 In the shown model, if the coordinates (xc0, yc0) of the front wheels C0, the coordinates (xb1, yb1) of the rear wheels B1, and the coordinates (xc1, yc1) of the towing point C1 are used, the following formulas (c2) to (c4) are established.

[0072] VC0·cosα1 = VB1…(c2)

[0073] xc0 = xb1 + l1·cosθ1…(c3)

[0074] xc1 = xb1 - h1·cosθ1…(c4)

[0075] If the expressions obtained by differentiating both sides of the above formulas (c3) and (c4) and formula (c2) are used, the following formula (c5) can be obtained.

[0076] h1·tanα1 + l1·tanγ1 = 0…(c5)

[0077] Based on the above formula (c5), the angle γ1 can be expressed by the steering angle α1. Therefore, the towing angle β can be expressed by the above formula (c1).

[0078] Return to Figure 8 , PU52 obtains the folded towing angle βth (S56). In this embodiment, the folded towing angle βth is a fixed value determined according to the maximum value of the steering angle α1.

[0079] That is, according to Figure 9 the model shown, the first-order time derivative value of the towing angle β is expressed by the following formula (c6).

[0080] dβ / dt

[0081] = -(Vtra / l2)·sinβ

[0082] - {Vtra / (l1·l2)}·(l2 + h1·cosβ)·tanα…(c6)

[0083] Here, in the case of generating a folding phenomenon, even if the steering angle α1 is changed to the maximum value α1th, the towing angle β cannot be changed. Therefore, the time derivative value of the towing angle β in the above formula (c6) is set to zero, and the towing angle β when the maximum value α1th is substituted into the steering angle α1 is regarded as the folded towing angle βth. However, since the steering angle α1 can take both positive and negative values, in the above formula (c6), both "α1th" and "(-1)·αth" can be substituted. Therefore, the folded towing angle βth actually takes two values. These two folded towing angles βth are pre-stored in the storage device 54. Moreover, in the process of S56, PU52 selects the value with the smaller absolute value of the difference from the towing angle β among the two values according to the sign of the steering angle α1 and the sign of the change speed of the steering angle α1.

[0084] Next, PU52 determines whether the absolute value of the difference between the towing angle β and the folded towing angle βth is below the threshold Δth (S58). This process is to determine whether it has become a state where a folding phenomenon is likely to occur. When PU52 determines that it is below the threshold Δth (S58: Yes), it warns the driver of the main idea of the state where a folding phenomenon is likely to occur by operating the speaker 84 (S60).

[0085] In addition, in the case where PU52 has completed the processing of S60 and in the case where a negative determination is made in the processing of S50 and S58, the series of processing is temporarily ended. Figure 8 The series of processing shown above.

[0086] In this way, in the present embodiment, the processing for suppressing the occurrence of the folding phenomenon is performed using the towing angle β. Moreover, the towing angle β, which is the input for this processing, is calculated without using the detected value of the yaw rate of the towing vehicle 20. Therefore, for example, even in a state where the towing vehicle 20 has stopped and only the trailer 30 is displaced, the accurately calculated towing angle β can be used.

[0087] <Other Embodiments>

[0088] In addition, the present embodiment can be modified as follows. The present embodiment and the following modification examples can be implemented in combination with each other within a range where there is no technical contradiction.

[0089] "Regarding the curvature variable"

[0090] · The curvature variable does not have to be the curvature ktr. For example, it can also be the radius of curvature.

[0091] "Regarding the curvature variable acquisition processing"

[0092] · The curvature variable acquisition processing is not limited to the processing of calculating the curvature ktr based on the yaw rate yr and the vehicle speed V as inputs. The curvature variable acquisition processing can also be, for example, the processing of calculating the curvature ktr based on the traveling trajectory of the trailer 30 as an input. Here, the traveling trajectory is the time-series data of the coordinates of the trailer 30. The processing of acquiring the coordinates of the trailer 30 can be, for example, a processing using the global positioning system or the like. In addition, the processing of acquiring the coordinates of the trailer 30 can also be a processing using the image data of the surroundings of the trailer 30 captured by a camera and the map data.

[0093] "Regarding the trailer length variable acquisition processing"

[0094] · The trailer length variable acquisition processing is not limited to the processing of accepting the user's input of the trailer length. For example, the trailer length variable acquisition processing can also be the processing of measuring the trailer length based on the image data of the trailer captured by a camera provided on the towing vehicle 20 as an input.

[0095] "Regarding the trailer length variable"

[0096] · The trailer length variable does not have to be the trailer length Lt. For example, the trailer length variable can also be a label variable indicating any one of large, medium, and small in terms of the magnitude of a value that can be obtained based on the trailer length Lt. In this case, the virtual steering angle calculation processing can also be the processing of calculating the virtual steering angle α2 using one trailer length Lt corresponding to each of large, medium, and small.

[0097] "Regarding the calculation and processing of the virtual steering operation angle"

[0098] · The calculation and processing of the virtual steering operation angle does not necessarily include the processing of the value of the independent variable input to the arctangent function. For example, the calculation and processing of the virtual steering operation angle can also be the processing of performing a mapping operation on the virtual steering operation angle α2 by the PU52 in a state where the mapping data is stored in the storage device 54. Here, the mapping data is data with the curvature ktr and the trailer length Lt as input variables and the virtual steering operation angle α2 as the output variable.

[0099] Here, the mapping data refers to a set of data of discrete values of the input variables and the values of the output variables corresponding to the values of the input variables respectively. In addition, the mapping operation can be the processing of taking the value of the output variable of the corresponding mapping data as the operation result when any one of the value of the input variable and the value of the input variable of the mapping data is the same. In addition, the mapping operation can be the processing of taking the value obtained by interpolating the values of multiple output variables included in the mapping data as the operation result when none of the value of the input variable and the value of the input variable of the mapping data is the same. In addition, instead of this case, the mapping operation can also be the processing of taking the value of the output variable of the mapping data corresponding to the closest value among the multiple input variables included in the mapping data as the operation result when none of the value of the input variable and the value of the input variable of the mapping data is the same.

[0100] "Regarding the control processing of the virtual steering operation angle"

[0101] · The control processing of the virtual steering operation angle is not limited to the processing of substituting the operation amount of the control with the virtual steering operation angle α2 as the control amount and the target virtual steering operation angle α2* as the target value of the control amount into the target steering angle α1*. For example, the control processing of the virtual steering operation angle can also be the processing of substituting the operation amount of the control with the virtual steering operation angle α2 as the control amount and the target virtual steering operation angle α2* as the target value of the control amount into the torque command value of the motor of the steering system 60.

[0102] · The control processing of the virtual steering operation angle does not necessarily have to be related to the control of the backward movement of the trailer 30. The control processing of the virtual steering operation angle can also be, for example, related to the forward control of the trailer 30.

[0103] "Regarding the calculation processing of the towing angle"

[0104] · The traction angle calculation process is not limited to the process of performing the operation using the above formula (c1). For example, in a state where the mapping data is stored in the storage device 54, the traction angle calculation process can also be a process of performing a mapping operation on the traction angle β by the PU52. Here, the mapping data is data with the steering angle α1 and the virtual steering operation angle α2 as input variables, and the traction angle β as the output variable.

[0105] "Regarding the operation process"

[0106] · The operation process is not limited to the process of S60. For example, the operation process can also be a process of operating the steering system 60 by using the steering system 60 as prescribed hardware. This can be achieved, for example, by including in the operation process a process of substituting the operation amount of the control that uses the traction angle β as the control amount and the target value of the traction angle β as the target value of the control amount into the target steering angle α1*.

[0107] · The operation process does not have to be a process related to the control of the backward movement of the trailer 30. The operation process can also be, for example, a process related to the forward control of the trailer 30.

[0108] "Regarding the prescribed hardware"

[0109] · In the process of S60, the process in which the prescribed hardware to be the operation object is the speaker 84 is illustrated, but it is not limited to this. For example, the warning light can also be the prescribed hardware. Additionally, for example, as described in the "Regarding the operation process" column, the steering system 60 can be the prescribed hardware.

[0110] "Regarding the control device"

[0111] · As the control device, it is not limited to a device that includes the PU52 and the storage device 54 and executes software processing. The control device can also include, for example, a dedicated hardware circuit such as an ASIC that executes at least a part of the processing executed in the above-described embodiment. That is, the control device can include any one of the following processing circuits (a) to (c). (a) A processing circuit that includes a processing device that executes all of the above-described processing according to a program and a program storage device such as a storage device that stores the program. (b) A processing circuit that includes a processing device and a program storage device that execute a part of the above-described processing according to a program and a dedicated hardware circuit that executes the remaining processing. (c) A processing circuit that includes a dedicated hardware circuit that executes all of the above-described processing. Here, the software execution device that includes the processing device and the program storage device and the dedicated hardware circuit can be multiple.

[0112] "Regarding the computer"

[0113] · As the computer, it is not limited to the PU52 mounted on the vehicle. For example, it can also be executed by the user's mobile terminalFigure 3 The processing shown and executed by PU52 Figure 4 and Figure 5 the processing shown.

[0114] "Regarding the vehicle"

[0115] · As the connecting vehicle, it is not limited to Figure 1 the vehicles exemplified.

[0116] Although the present disclosure has been described based on embodiments, it should be understood that the present disclosure is not limited to these embodiments and structures. The present disclosure also includes various modifications and variations within the equivalent scope. In addition, various combinations, manners, and even other combinations and manners including only one element, more or fewer elements are also included in the scope and thinking range of the present disclosure.

[0117] The description "at least one of A and B" in this specification should be understood to mean "only A, or only B, or both A and B".

Claims

1. An arithmetic device for a coupled vehicle, which is applied to a coupled vehicle including a towing vehicle and a trailer towed by the towing vehicle, wherein, the arithmetic device of the coupled vehicle is configured to execute a curvature variable acquisition process, a trailer length variable acquisition process, and a virtual steering angle calculation process, the curvature variable acquisition process is a process of acquiring the value of the curvature variable, the curvature variable is a variable representing the curvature of the traveling trajectory of the trailer, the trailer length variable acquisition process is a process of acquiring the value of the trailer length variable, the trailer length variable is a variable representing the length of the trailer, the virtual steering angle calculation process is a process of calculating the virtual steering angle by using the value of the curvature variable and the value of the trailer length variable as inputs, the virtual steering angle is an angle representing the displacement direction of the connection part between the trailer and the towing vehicle.

2. The arithmetic device for a coupled vehicle according to claim 1, wherein, it is configured to execute a steering angle acquisition process and a towing angle calculation process, the steering angle acquisition process is a process of acquiring the steering angle of the steering wheel of the towing vehicle, the towing angle calculation process is a process of calculating the towing angle by using the virtual steering angle and the steering angle as inputs, the towing angle is an angle formed by the longitudinal direction of the towing vehicle and the longitudinal direction of the trailer.

3. The arithmetic device for a coupled vehicle according to claim 1, wherein, it is configured to execute a yaw rate acquisition process and a vehicle speed acquisition process, the yaw rate acquisition process is a process of acquiring the yaw rate of the trailer, the vehicle speed acquisition process is a process of acquiring the vehicle speed of the trailer, the curvature variable acquisition process is a process of acquiring the value of the curvature variable by calculating the value of the curvature variable by using the yaw rate and the vehicle speed as inputs.

4. The arithmetic device for a coupled vehicle according to claim 3, wherein, a yaw rate sensor is provided on the trailer, the yaw rate acquisition process is a process of acquiring the yaw rate detected by the yaw rate sensor.

5. The arithmetic device for a coupled vehicle according to claim 3, wherein, wheel speed sensors for detecting the speeds of the left and right wheels are provided on the trailer, the yaw rate acquisition process is a process of acquiring the yaw rate by calculating the yaw rate by using the detection values of the wheel speeds of the left and right wheels detected by the wheel speed sensors as inputs.

6. A control device for a coupled vehicle, wherein, it is configured to execute each of the above processes executed by the arithmetic device for a coupled vehicle according to claim 1 and a virtual steering angle control process, the virtual steering angle control process is a process of operating the steering angle of the towing vehicle by using the virtual steering angle as a control amount and the target virtual steering angle as a target value of the control operation amount.

7. A control device for a coupled vehicle, wherein, it is configured to execute each of the above processes executed by the arithmetic device for a coupled vehicle according to claim 2 and an operation process, the operation process is a process of operating a specified hardware by using the towing angle as an input.

8. An arithmetic method for a coupled vehicle, wherein, Applied to a coupled vehicle having a towing vehicle and a trailer towed by the towing vehicle, It includes performing a curvature variable acquisition process, a trailer length variable acquisition process, and a virtual steering angle calculation process, The above-mentioned curvature variable acquisition process is a process of acquiring the value of the curvature variable, The above-mentioned curvature variable is a variable representing the curvature of the traveling trajectory of the above-mentioned trailer, The above-mentioned trailer length variable acquisition process is a process of acquiring the value of the trailer length variable, The above-mentioned trailer length variable is a variable representing the length of the above-mentioned trailer, The above-mentioned virtual steering angle calculation process is a process of calculating the virtual steering angle with the values of the above-mentioned curvature variable and the above-mentioned trailer length variable as inputs, The above-mentioned virtual steering angle is an angle representing the displacement direction of the connection part between the above-mentioned trailer and the above-mentioned towing vehicle.

9. An arithmetic program for a coupled vehicle, wherein, Applied to a coupled vehicle having a towing vehicle and a trailer towed by the towing vehicle, It causes a computer to execute a curvature variable acquisition process, a trailer length variable acquisition process, and a virtual steering angle calculation process, The above-mentioned curvature variable acquisition process is a process of acquiring the value of the curvature variable, The above-mentioned curvature variable is a variable representing the curvature of the traveling trajectory of the above-mentioned trailer, The above-mentioned trailer length variable acquisition process is a process of acquiring the value of the trailer length variable, The above-mentioned trailer length variable is a variable representing the length of the above-mentioned trailer, The above-mentioned virtual steering angle calculation process is a process of calculating the virtual steering angle with the values of the above-mentioned curvature variable and the above-mentioned trailer length variable as inputs, The above-mentioned virtual steering angle is an angle representing the displacement direction of the connection part between the above-mentioned trailer and the above-mentioned towing vehicle.

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