Return control device for connected vehicle

Abstract

The invention provides a reverse control device, which starts reverse of a connected vehicle based on automatic driving only when conditions for properly performing automatic driving are provided, and can stably perform reverse of the connected vehicle based on automatic driving. An automatic driving ECU (71) functioning as a retreat control device is mounted on a towing vehicle (11) of a connected vehicle (1) connecting a towed vehicle (12) to the towing vehicle (11), and controls the towing vehicle (11) during automatic retreat driving in which the connected vehicle (1) is retreated by automatic driving. An automatic driving ECU (71) starts automatic back-up driving when traction back-up start conditions including a vehicle speed of a traction vehicle (11) being equal to or less than a predetermined value and a steering torque of the traction vehicle (11) being equal to or less than a predetermined value are satisfied.

Description

Technical Field

[0001] The present invention relates to a coupling vehicle reverse control device for controlling a towing vehicle when a towed vehicle is towed to a towing vehicle and when the coupling vehicle reverses. Background Art

[0002] The towed vehicle towed to the towing vehicle follows the towing vehicle when the towed vehicle moves forward, so the driving operation is relatively easy. However, when the towed vehicle is moved backward, such as when parking in a parking space, the towed vehicle does not necessarily move in the direction corresponding to the steering angle of the towing vehicle, so the driving operation is difficult, especially when the driver of the towing vehicle is not proficient in driving the tow vehicle. Therefore, a device and method for assisting the driving operation when the towed vehicle moves backward are proposed. For example, the automatic or semi-automatic driving system described in Patent Document 1 can issue action instructions to the system through sounds such as "10 feet back", "stop", "turn right 90 degrees" issued by the operator in the vehicle cabin.

[0003] Patent Document 1: U.S. Patent No. 9688306

[0004] In a reverse control device capable of automatically performing reverse of a coupled vehicle, the coupled vehicle may not be properly guided to a destination by automatic driving depending on the state of the towing vehicle when reverse starts. Therefore, an object of the present invention is to provide a reverse control device capable of stably performing reverse of the coupled vehicle by automatic driving by starting reverse of the coupled vehicle by automatic driving only when conditions for appropriately performing automatic driving are met. Summary of the invention

[0005] In order to achieve the above-mentioned object, the present invention provides a reverse control device for a coupled vehicle, which is mounted on the coupled vehicle that couples a towed vehicle to a towing vehicle equipped with a steering control device, and controls the towing vehicle during automatic reverse driving in which the coupled vehicle is reversed by automatic driving, and starts the automatic reverse driving when all starting conditions including that the vehicle speed of the towing vehicle is below a specified value and the steering torque of the towing vehicle is below a specified value are satisfied.

[0006] According to the reverse control device of the present invention, the reverse of the connected vehicles by automatic driving is started only when the conditions for appropriately performing automatic driving are met, and the reverse of the connected vehicles by automatic driving can be stably performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a bird's-eye view showing the connected vehicles according to the first embodiment of the present invention.

[0008] Figure 2 1 is a schematic structural diagram showing a structural example of a pulling angle sensor.

[0009] Figure 3 This is a schematic structural diagram showing a structural example of a traction vehicle.

[0010] Figure 4 This is a control block diagram showing the configuration of a control system composed of a plurality of ECUs.

[0011] Figure 5 This is a flowchart showing an example of processing performed by the automatic driving ECU. DETAILED DESCRIPTION

[0012] [First embodiment]

[0013] The first embodiment of the present invention is described with reference to the drawings. The embodiments described below are shown as preferred specific examples when implementing the present invention, and there are also parts that specifically illustrate various technical matters that are technically preferred, but the technical scope of the present invention is not limited to these specific forms.

[0014] Figure 1 1 is a bird's-eye view showing a coupled vehicle 1 according to the present embodiment. The coupled vehicle 1 includes a tractor vehicle 11 and a towed vehicle 12. When the vehicle is moving forward, the towed vehicle 12 is towed by the tractor vehicle 11. The tractor vehicle 11 and the towed vehicle 12 are coupled by a tractor-side coupling member 13 on the tractor vehicle 11 side and a towed-side coupling member 14 on the towed vehicle 12 side. Figure 1 In the figure, as an example, the towed vehicle 12 is shown as a box-shaped camper, but the towed vehicle 12 is not limited to this, and may be, for example, a boat trailer carrying a small boat or a cargo trailer.

[0015] The traction-side coupling member 13 is provided with a spherical hooking ball 131, and the towed-side coupling member 14 has a coupler 141 covering the hooking ball 131, a locking mechanism 142 for preventing the coupler 141 from falling off relative to the hooking ball 131 by operating a lever 142a, and a rod-shaped tongue 143 for fixing the coupler 141 to the front end. The towed-side coupling member 14 can swing around the hooking point 131a, which is the center point of the hooking ball 131.

[0016] exist Figure 1, the center line 11a of the tractor vehicle 11 along the front-rear direction of the tractor vehicle 11 and the center line 12a of the towed vehicle 12 along the front-rear direction of the towed vehicle 12 are respectively indicated by dot-dash lines. When the coupled vehicle 1 is viewed from above, the center line 11a of the tractor vehicle 11 and the center line 12a of the towed vehicle 12 along the front-rear direction of the towed vehicle 12 intersect at the hitch point 131a. The angle θh formed by the center line 11a of the tractor vehicle 11 and the center line 12a of the towed vehicle 12 along the front-rear direction of the towed vehicle 12 is a towing angle indicating the tilt angle of the towed vehicle 12 relative to the tractor vehicle 11. The towing angle is detected by a towing angle sensor.

[0017] Figure 2 1 is a schematic structural diagram showing a structural example of the traction angle sensor 81. The traction angle sensor 81 includes a gear-shaped magnetic body 811 fixed to the coupling 141, and a magnetic sensor 812 mounted on the traction-side connecting member 13, the magnetic sensor 812 facing the outer periphery of the magnetic body 811. The intensity of the magnetic field detected by the magnetic sensor 812 changes due to the rotation of the magnetic body 811 relative to the magnetic sensor 812, and thus the traction angle can be detected by the change in the intensity of the magnetic field.

[0018] Figure 3 1 is a schematic structural diagram showing a structural example of a tractor vehicle 11. The tractor vehicle 11 includes left and right front wheels 21, 22 as steering wheels and left and right rear wheels 23, 24 as non-steering wheels, and has an automatic driving function that can automatically steer the left and right front wheels 21, 22 at least when the coupled vehicle 1 moves backward. In addition, in the present embodiment, the tractor vehicle 11 is an electric vehicle that uses a drive motor 30 that generates a driving force by receiving a supply of electric current as a driving source. The tractor vehicle 11 is equipped with a battery 31 and an inverter 32, and the direct current output from the battery 31 is converted into an alternating current by the inverter 32 and supplied to the drive motor 30. When the driver drives the tractor vehicle 11, the magnitude of the current supplied to the drive motor 30 changes according to the amount of depression of the accelerator pedal 111.

[0019] The drive motor 30 is, for example, an IPM (Interior Permanent Magnet) synchronous motor having a stator that generates a rotating magnetic field by an AC current supplied from an inverter 32, and a rotor that rotates relative to the stator, and a plurality of permanent magnets embedded in the rotor, but an electric motor having a structure other than this may be used as the drive motor 30. In addition, the driving source of the traction vehicle 11 may be an internal combustion engine, or a hybrid system in which an engine and an electric motor are combined.

[0020] The torque output from the drive motor 30 is transmitted from the pinion 301 fixed to the output rotating shaft 300 of the drive motor 30 to the ring gear 302, and is input to the differential device 33. The differential device 33 includes: a differential case 331 to which the ring gear 302 is fixed, a pinion shaft 332 fixed to the differential case 331, a plurality of pinions 333 axially supported by the pinion shaft 332, and a pair of side gears 334 and 335 that orthogonally intersect and mesh with the pinion shaft 333.

[0021] The left drive shaft 34 is connected to one side gear 334 of the differential device 33, and the right drive shaft 35 is connected to the other side gear 335. The torque input to the differential device 33 is distributed to the left front wheel 21 and the right front wheel 22 via the drive shafts 34 and 35.

[0022] The left and right front wheels 21 and 22 are steered by the steering device 4. The steering device 4 includes a steering wheel 40 that is steered by the driver of the tractor vehicle 11, a steering shaft 41 connected to the steering wheel 40, a rack shaft 42 that moves forward and backward in the vehicle width direction by the rotation of the steering shaft 41, tie rods 44 that are swingably connected to both ends of the rack shaft 42 via ball joints 43, and an electric power steering (EPS) device 45. The electric power steering device 45 functions as a steering assist device that generates a steering assist force that assists the steering operation of the steering wheel 40 during manual driving in which the driver steers the steering wheel 40, and functions as an actuator that moves the rack shaft 42 and steers the left and right front wheels 21 and 22 during automatic driving.

[0023] The front wheels 21, 22 and the rear wheels 23, 24 are respectively provided with rubber tires 212, 222, 232, 242 on metal wheels 211, 221, 231, 241. In addition, brake devices 51 to 54 are respectively provided on the front wheels 21, 22 and the rear wheels 23, 24. The brake devices 51 to 54 generate a braking force of a strength corresponding to the amount of depression of the brake pedal 112.

[0024] The tractor vehicle 11 is equipped with a plurality of cameras for photographing the surroundings of the coupled vehicle 1. In the present embodiment, as the plurality of cameras, a front camera 61 for photographing the front of the tractor vehicle 11, a rear camera 62 for photographing the rear of the tractor vehicle 11, a left side camera 63 for photographing the left side of the tractor vehicle 11, and a right side camera 64 for photographing the right side of the tractor vehicle 11 are mounted. The front camera 61 is disposed at the front end of the tractor vehicle 11, and the rear camera 62 is disposed at the rear end of the tractor vehicle 11. The left side camera 63 and the right side camera 64 are disposed at the left and right vehicle side reflectors 113 and 114, respectively.

[0025] Image information of images captured by the front camera 61, the rear camera 62, the left side camera 63, and the right side camera 64 is sent to the image processing device 60. The image processing device 60 analyzes the image information from the cameras 61 to 64 to grasp the surrounding conditions of the connected vehicle 1, and recognizes the obstacle if there is an obstacle. Alternatively, a camera may be mounted on the towed vehicle 12, and the image processing device 60 may recognize obstacles around the connected vehicle 1 including the image information of the camera.

[0026] The tractor vehicle 11 is provided with a shift lever 115. The driver can shift the shift lever 115 to a parking position for immobilizing the tractor vehicle 11, a reverse position for reverse travel, a neutral position, and a forward position for forward travel.

[0027] In addition, a touch panel display (TPD: Touch Panel Display) 116 is installed in the tractor vehicle 11 at a position where the driver can operate. The touch panel display 116 is used not only as a display of the car navigation system, but also for displaying an image of the surroundings of the connected vehicle 1 produced by the image processing device 60. The image processing device 60 synthesizes a bird's-eye view image of the surroundings of the connected vehicle 1 based on image information obtained from the cameras 61 to 64, for example, and displays it on the touch panel display 116.

[0028] In addition, a start button 117 operated by the driver is provided on the tractor vehicle 11. The start button 117 is a button for starting the reverse movement of the coupled vehicle 1 by automatic driving. The start button 117 is, for example, a push button switch, but is not limited thereto, and a virtual button displayed on the touch panel display 116 may be used as the start button.

[0029] Figure 4 This is a control block diagram showing the structure of a control system 7 composed of a plurality of ECUs (Electronic Control Units) mounted on a tractor vehicle 11. The control system 7 includes an automatic driving ECU 71, a driving ECU 72, a steering ECU 73, and a braking ECU 74. Each of the ECUs 71 to 74 is connected to an on-vehicle network 70 such as a CAN (Controller Area Network) or a LIN (Local Interconnect Network) to enable bidirectional communication.

[0030] Each ECU 71 to 74 can acquire detection results of a plurality of sensors disposed at various parts of the tractor vehicle 11 via the in-vehicle network 70. The plurality of sensors include a traction angle sensor 81 for detecting a traction angle between the tractor vehicle 11 and the towed vehicle 12, a wheel speed sensor 82 for detecting the rotation speed of the front wheels 21, 22 and the rear wheels 23, 24, a voltage sensor 83 for detecting the voltage of the battery 31, a steering angle sensor 84 for detecting a steering angle of the steering wheel 20, a steering torque sensor 85 for detecting a steering torque applied to the steering wheel 20, an EPS temperature sensor 86 for detecting the temperature of the electric power steering device 45, an accelerator pedal sensor 87 for detecting a depression amount of the accelerator pedal 111, a brake pedal sensor 88 for detecting a depression amount of the brake pedal 112, and a shift position sensor 89 for detecting the position of the shift lever 115.

[0031] When the driver performs manual driving of the tractor vehicle 11, the drive ECU 72 outputs a PWM (Pulse Width Modulation) signal to the inverter 32 based on the detection results of the accelerator pedal sensor 87 and the shift position sensor 89 to control the drive motor 30. The steering ECU 73 controls the electric power steering device 45 based on the detection results of the steering angle sensor 84 and the steering torque sensor 85. The brake ECU 74 controls the brake devices 51 to 54 based on the detection results of the brake pedal sensor 88 and the wheel speed sensor 82.

[0032] The automatic driving ECU 71 is an ECU that controls the automatic driving of the towing vehicle 11, and functions as a reverse control device when the coupled vehicle 1 moves backward. The automatic driving ECU 71 can send instructions to the drive ECU 72, the steering ECU 73, and the brake ECU 74 during automatic driving to perform various actions. Specifically, it can send a driving force instruction signal to the drive ECU 72 to cause the drive motor 30 to generate a driving force corresponding to the driving force instruction signal. In addition, the automatic driving ECU 71 can send a steering angle instruction signal to the steering ECU 73 to cause the front wheels 21 and 22 to turn at an angle corresponding to the steering angle instruction signal. In addition, the automatic driving ECU 71 can send a braking force instruction signal to the brake ECU 74 to cause the brake devices 51 to 54 to generate a braking force corresponding to the braking force instruction signal.

[0033] In addition, the automatic driving ECU 71 can communicate with the image processing device 60, and can obtain information on the presence or absence of obstacles recognized by the image processing device 60, and information on the position and size of the obstacles when there are obstacles. In addition, the automatic driving ECU 71 can obtain information indicating the operation status of the start button 117.

[0034] When all of the plurality of towing reverse start conditions are satisfied, the automatic driving ECU 71 starts towing reverse control for causing the connected vehicle 1 to reverse by automatic driving. Hereinafter, the automatic driving for causing the towing vehicle 11 to reverse is referred to as automatic reverse driving. In addition, the so-called automatic driving here is not only causing the towing vehicle 11 to travel without the driver of the towing vehicle 11 operating any of the steering wheel 20, the accelerator pedal 111, and the brake pedal 112, but also includes the so-called driving assistance in which the driver operates the accelerator pedal 111 and the brake pedal 112 without operating the steering wheel 20.

[0035] The person who performs the operation to start the automatic reverse driving of the coupled vehicle 1 is not limited to the driver of the tractor vehicle 11, and may be, for example, a passenger of the tractor vehicle 11 or a person riding in the towed vehicle 12, or a person who is neither riding in the tractor vehicle 11 nor in the towed vehicle 12. Hereinafter, the person who performs the operation to start the automatic reverse driving is referred to as an operator.

[0036] The operator specifies at least one of the travel direction and the target position during automatic reverse driving. This specification can be performed using, for example, the touch panel display 116, but the travel direction and the target position of the connected vehicle 1 can also be specified by operating an operating device provided in the tractor vehicle 11 or the towed vehicle 12, or by operating a wireless information terminal of the operator.

[0037] The plurality of tow-back start conditions include the following first to twelfth conditions. The automatic driving ECU 71 starts tow-back control when all of the first to twelfth conditions are satisfied.

[0038] The first condition is that the speed of the tractor vehicle 11 is less than a predetermined value. The automatic driving ECU 71 can obtain the speed of the tractor vehicle 11 based on the detection result of the wheel speed sensor 82, for example. The predetermined value in the first condition is a small value that satisfies the first condition only when the tractor vehicle 11 is substantially stopped. In other words, the first condition can also be said to be that the tractor vehicle 11 is stopped.

[0039] The second condition is that the accelerator pedal 111 is not stepped on. Based on the detection result of the accelerator pedal sensor 87, the automatic driving ECU 71 can determine that the second condition is satisfied when the stepping amount of the accelerator pedal 111 is less than a specified value. The specified value in the second condition is a value less than the stepping amount set as the clearance in the accelerator pedal 111. In addition, the so-called clearance here refers to a region with a small stepping amount where the stepping operation of the accelerator pedal 111 does not affect the control of the drive motor 30.

[0040] The third condition is that the towing vehicle 11 is braked. The automatic driving ECU 71 can determine that the third condition is satisfied when the depression amount of the brake pedal 112 is greater than a predetermined value based on the detection result of the brake pedal sensor 88, for example. In addition, it is not limited to the brake (pedal brake) that is activated by depression of the brake pedal 112. For example, when the towing vehicle 11 is braked by the parking brake, it can also be determined that the third condition is satisfied.

[0041] The fourth condition is that the steering torque is below a specified value. The automatic driving ECU 71 can determine whether the fourth condition is satisfied or not based on the detection result of the steering torque sensor 85. The specified value in the fourth condition is a small value that satisfies the fourth condition only when the steering wheel 20 is not steered. In other words, the fourth condition can also be said to be that the steering wheel 20 is not steered.

[0042] The fifth condition is that the shift lever 115 is in the reverse gear. The automatic driving ECU 71 can determine whether the fifth condition is satisfied or not based on the detection result of the shift position sensor 89.

[0043] The sixth condition is that the drive ECU 72, the steering ECU 73, and the brake ECU 74 operate normally. The automatic driving ECU 71 can determine that the sixth condition is satisfied when the communication with the drive ECU 72, the steering ECU 73, and the brake ECU 74 is performed normally, and the information obtained from the drive ECU 72, the steering ECU 73, and the brake ECU 74 does not include information indicating that an abnormality has occurred in each ECU 72 to 74.

[0044] The seventh condition is that no abnormality occurs in the control object devices of the drive ECU 72, the steering ECU 73 and the brake ECU 74. Here, the control object devices of the drive ECU 72 are the drive motor 30 and the inverter 32. The control object device of the steering ECU 73 is the electric power steering device 45. The control object device of the brake ECU 74 is the brake devices 51 to 54. The automatic driving ECU 71 can determine whether the seventh condition is met based on the information obtained through communication with the drive ECU 72, the steering ECU 73 and the brake ECU 74. For example, when the information obtained from the steering ECU 73 contains information indicating overheating of the electric power steering device 45, the seventh condition does not meet.

[0045] The eighth condition is that the voltage of the battery 31 is within an appropriate range. The automatic driving ECU 71 can determine whether the eighth condition is satisfied or not based on the detection result of the voltage sensor 83.

[0046] The ninth condition is that the above-mentioned sensors 81 to 89 operate normally. For example, when the detection result of any one of the sensors 81 to 89 is not within the normal range, the automatic driving ECU 71 determines that the ninth condition does not hold. In addition, when the steering angle sensor 84 is not an absolute encoder capable of detecting the absolute position of the steering angle, but is, for example, an incremental encoder that outputs a pulse signal, the automatic driving ECU 71 also determines that the ninth condition does not hold when the offset adjustment of the neutral position of the steering wheel 20 is not completed. In addition, the automatic driving ECU 71 also determines that the ninth condition does not hold when the offset adjustment of the traction angle detected by the traction angle sensor 81 is not completed. In addition, the offset adjustment of the neutral position of the steering wheel 20 and the offset adjustment of the traction angle can be performed, for example, by setting the steering angle and the traction angle to zero when the connected vehicle 1 travels a predetermined distance in a straight line in the forward direction.

[0047] In addition, the automatic driving ECU 71 also determines that the ninth condition is not satisfied when it is determined that the towing angle is not correctly detected by the towing angle sensor 81. That is, the ninth condition includes: the towing angle between the towing vehicle 11 and the towed vehicle 12 is correctly detected by the towing angle sensor 81. The determination of whether the towing angle is correctly detected by the towing angle sensor 81 can be performed, for example, based on the images captured by the rear camera 62, the left side camera 63, and the right side camera 64, by comparing the images with the detection value of the towing angle sensor 81. Specifically, for example, when the towing angle detected by the towing angle sensor 81 is 0°, but the towed vehicle 12 is detected to be tilted in the horizontal direction relative to the towing vehicle 11 based on the images of the rear camera 62, the left side camera 63, and the right side camera 64, it is determined that the towing angle is not correctly detected by the towing angle sensor 81.

[0048] The tenth condition is that no obstacle that becomes an obstacle to the reverse travel is found by the images of the front camera 61, the rear camera 62, the left side camera 63, and the right side camera 64. Based on the information obtained from the image processing device 60, the automatic driving ECU 71 determines that the tenth condition is satisfied when it is determined that there is no obstacle that becomes an obstacle to the reverse travel around the tractor vehicle 11 or the towed vehicle 12 in the travel direction specified by the operator, or around the tractor vehicle 11 or the towed vehicle 12 on the path to the target position specified by the operator, and determines that the tenth condition is not satisfied when it is determined that there is such an obstacle.

[0049] The eleventh condition is that the operator performs an instruction operation to instruct the start of automatic driving when all the first to tenth conditions are satisfied. This instruction operation can be performed, for example, by operating the start button 117 of automatic reverse driving as described above, but it is also possible to perform an instruction operation to cause the automatic driving ECU 71 to start towing reverse control by operating an operating device provided in the towing vehicle 11 or the towed vehicle 12, or by operating the operator's wireless information terminal.

[0050] The twelfth condition is that the towed vehicle 12 is connected to the towing vehicle 11. The automatic driving ECU 71 can make this determination based on, for example, whether the information of the towing angle can be obtained from the towing angle sensor 81. In addition, the automatic driving ECU 71 can also determine whether the towed vehicle 12 is connected to the towing vehicle 11 based on the image of the rear camera 62, in particular, by using information obtained from the image processing device 60.

[0051] Furthermore, when the first to eleventh conditions are satisfied but the twelfth condition is not satisfied, the automatic driving ECU 71 starts the non-towing reverse control for causing the towing vehicle 11 in a state where it is not connected to the towed vehicle 12 to reverse by automatic driving. That is, when the towed vehicle 12 is not connected to the towing vehicle 11 when the instruction operation of the eleventh condition is performed, the automatic driving ECU 71 causes only the towing vehicle 11 to reverse by automatic driving through the non-towing reverse control.

[0052] When all the first to twelfth conditions are met, the automatic driving ECU 71 starts the towing reverse control. During the execution of the towing reverse control, the automatic driving ECU 71 calculates the target value of the towing angle for moving the coupled vehicle 1 toward the travel direction or target position specified by the operator, sends a command to the steering ECU 73 to make the actual towing angle consistent with the target value, and steers the left and right front wheels 21 and 22 through the steering device 4. However, when the first to twelfth conditions are met, the towing vehicle 11 is braked by the third condition, so the reverse travel of the coupled vehicle 1 is started after the braking state is released. The speed of the towing vehicle 11 during the reverse travel can also be controlled by the automatic driving ECU 71, but can also be adjusted by the driver operating the accelerator pedal 111 or the brake pedal 112.

[0053] After starting the tow-back control, the automatic driving ECU 71 stops the tow-back control when any of the fourth to tenth conditions is not satisfied, and stops the coupled vehicle 1. The automatic driving ECU 71 also stops the tow-back control when any of the first to third stop conditions described below is satisfied.

[0054] The first stop condition is that the brake pedal 112 is depressed with such a strength that the tractor vehicle 11 is stopped. Specifically, for example, when the depression amount of the brake pedal 112 is greater than the specified value of the third condition, the towing reverse control is stopped. Thus, for example, when the driver of the tractor vehicle 11 perceives some danger based on the surrounding conditions, the tractor vehicle 11 can be stopped immediately by stepping on the brake pedal 112 with force. However, when the position of the tractor vehicle 11 is near the target position, the driver may step on the brake pedal 112 to adjust the speed, so the specified value of the depression amount of the brake pedal 112 for stopping the towing reverse control is made greater than the specified value of the third condition.

[0055] That is, the automatic driving ECU 71 has the following functions: during automatic reverse driving of the connected vehicle 1 toward the target position, the driving speed can be adjusted by the amount of depression of the brake pedal 112, and when the depression amount of the brake pedal 112 becomes greater than a specified value, the automatic reverse driving is stopped, and when the connected vehicle 1 reaches the vicinity of the target position, the specified value of the depression amount of the brake pedal 112 is made greater than before the connected vehicle 1 reaches the vicinity of the target position.

[0056] The second stop condition is that the operator instructs the stop of the automatic driving, or the target position designated by the operator is reached. In addition, the operator's instruction to stop the automatic driving can be performed by, for example, operating the start button 117 again. In addition, the instruction to stop the automatic driving can also be performed by operating an operating device provided in the tractor vehicle 11 or the towed vehicle 12, or by operating a wireless information terminal of the operator.

[0057] The third stop condition is that the traction angle between the traction vehicle 11 and the towed vehicle 12 becomes greater than a specified value due to the slip of the traction vehicle 11 or the towed vehicle 12 due to, for example, side wind, inclination of the road surface, etc. The specified value of the traction angle is an angle at which a jackknife phenomenon occurs. Here, the so-called jackknife phenomenon refers to a phenomenon in which the traction angle only increases even when the traction vehicle 11 moves backward, but the towed vehicle 12 does not move backward. In such a case, after the driver manually moves the traction vehicle 11 forward and reduces the traction angle, the operator starts the traction reverse control based on the automatic driving ECU 71 again.

[0058] In addition, after the automatic driving ECU 71 starts the non-towing reverse control of the towing vehicle 11 not connected to the towed vehicle 12, if any one of the fourth to tenth conditions is not satisfied, or if the above-mentioned first stop condition or second stop condition is satisfied, the non-towing reverse control is stopped.

[0059] Figure 5: is a flowchart showing an example of the processing executed by the automatic driving ECU 71. The automatic driving ECU 71 repeatedly executes the processing of the flowchart in a predetermined control cycle.

[0060] The automatic driving ECU 71 determines whether the towing reverse control is being executed (step S1). If the towing reverse control is being executed, it determines whether the fourth to tenth conditions are met (step S2). If the determination result of step S2 is yes, the automatic driving ECU 71 determines whether the first to third stop conditions are not met (step S3). If the determination result is yes, the towing reverse control is continued (step S4). On the other hand, if the determination result of step S2 or step S3 is no, the automatic driving ECU 71 stops the towing reverse control (step S5).

[0061] In addition, when the result of the determination in step S1 is negative, the automatic driving ECU 71 determines whether the non-traction reverse control is being executed (step S6), and when the non-traction reverse control is being executed, determines whether the fourth to tenth conditions are satisfied (step S7). When the result of the determination in step S7 is positive, the automatic driving ECU 71 determines whether both the first stop condition and the second stop condition are not satisfied (step S8), and when the result of the determination is positive, the non-traction reverse control is continued (step S9). On the other hand, when the result of the determination in step S7 or step S8 is negative, the automatic driving ECU 71 stops the non-traction reverse control (step S10).

[0062] In addition, if the result of the determination in step S6 is negative, the automatic driving ECU 71 determines whether the first to eleventh conditions are satisfied (step S11), and if the result of the determination is positive, determines whether the twelfth condition is satisfied (step S12). If the result of the determination in step S12 is positive, the automatic driving ECU 71 starts the towing reverse control (step S13), and if the result of the determination in step S12 is negative, starts the non-towing reverse control (step S14). On the other hand, if the result of the determination in step S11 is negative, the automatic driving ECU 71 ends. Figure 5 Processing of the flowchart shown.

[0063] According to the first embodiment described above, the reverse movement of the connected vehicle 1 by automatic driving is started only when all of the first to twelfth conditions are satisfied, so that the automatic reverse driving of the connected vehicle 1 can be stably performed.

[0064] [Second Embodiment]

[0065] Next, the second embodiment of the present invention will be described. In the first embodiment described above, the case where the operator instructs the start of automatic reverse driving by operating the start button 117, operating the operating device provided in the towing vehicle 11 or the towed vehicle 12, or operating the wireless information terminal by the operator is described. However, in the present embodiment, the automatic driving ECU 71 starts the automatic reverse driving by the instruction operation based on the operation of the accelerator pedal 111 by the driver of the towing vehicle 11. More specifically, when the depression amount of the accelerator pedal 111 is greater than a predetermined value based on the detection result of the accelerator pedal sensor 87, the automatic driving ECU 71 starts the automatic reverse driving.

[0066] In addition, in the first embodiment described above, the condition for starting the towing reverse control or the non-towing reverse control includes that the accelerator pedal 111 is not stepped on (the second condition), but in the present embodiment, this condition is excluded. In addition, in the present embodiment, in order to clearly distinguish from the driving operation during manual driving (non-automatic driving) by the driver, as a necessary condition for starting the towing reverse control or the non-towing reverse control, the towing vehicle 11 is in the automatic driving mode. That is, in the present embodiment, the eleventh condition described above is that the accelerator pedal 111 of the towing vehicle 11 is operated when the first condition and the third to tenth conditions are all met and the towing vehicle 11 is in the automatic driving mode.

[0067] In addition, whether the automatic driving mode is in operation can be determined based on the setting state of a switch for switching between the manual driving mode and the automatic driving mode, for example. Alternatively, the automatic driving mode can be determined by the operator setting a target position or a travel direction.

[0068] According to the second embodiment, in addition to the effects of the first embodiment described above, operation of the start button 117 is not required when starting reverse driving based on automatic driving, thereby reducing the driver's operational burden when, for example, adjusting the vehicle speed during reverse driving based on the amount of depression of the driver's accelerator pedal 111.

[0069] (Note)

[0070] The present invention has been described above based on the first and second embodiments, but these embodiments do not limit the invention involved in the claims. In addition, it should be noted that all combinations of features described in the embodiments are not necessarily necessary for solving the problems of the invention. In addition, the present invention can be implemented by omitting a part of the structure, or adding or replacing the structure, and appropriately deforming it within the scope of its main purpose.

[0071] Description of Reference Numerals

[0072] 1…connected vehicle; 4…steering control device; 11…tracting vehicle; 12…towed vehicle; 45…electric power steering device; 61…front camera; 62…rear camera; 63…left side camera; 64…right side camera; 71…autopilot ECU (reverse control device); 81…traction angle sensor; 111…accelerator pedal; 112…brake pedal.

Claims

1. A reverse control device for a coupled vehicle, mounted on a traction vehicle that couples a towed vehicle to a traction vehicle equipped with a steering device, and controls the traction vehicle during automatic reverse driving in which the coupled vehicle is reversed by automatic driving, wherein: The automatic reverse driving is started when all starting conditions, including that the vehicle speed of the towing vehicle is equal to or less than a predetermined value and the steering torque of the towing vehicle is equal to or less than a predetermined value, are satisfied.

2. The reverse control device for a coupled vehicle according to claim 1, wherein: The start condition includes an operator performing an instruction operation to instruct the start of the automatic reverse driving in a state where the vehicle speed of the towing vehicle is equal to or less than a predetermined value and the steering torque of the towing vehicle is equal to or less than a predetermined value.

3. The reverse control device for a coupled vehicle according to claim 2, wherein: The instruction operation is an operation of a start button for the automatic reverse driving.

4. The reverse control device for a coupled vehicle according to claim 2, wherein: The instruction operation is to operate an accelerator pedal of the towing vehicle.

5. The reverse control device for a coupled vehicle according to claim 2, wherein: When the instruction operation is performed, if the towed vehicle is not coupled to the towing vehicle, only the towing vehicle is caused to move backward by automatic driving.

6. The reverse control device for a coupled vehicle according to claim 1, wherein: The start condition includes that no obstacle that hinders the reverse travel of the connected vehicle is found by an image of a camera capturing the periphery of the connected vehicle.

7. The reverse control device for a coupled vehicle according to claim 1, wherein: The start condition includes correctly detecting the traction angle between the traction vehicle and the towed vehicle by a traction angle sensor.

8. The reverse control device for a coupled vehicle according to claim 7, wherein: By capturing an image of a camera around the coupled vehicle, it is determined whether the hitch angle is correctly detected by the hitch angle sensor.

9. The reverse control device for a coupled vehicle according to claim 1, wherein: When a towing angle between the towing vehicle and the towed vehicle becomes equal to or larger than a predetermined value, the automatic reverse driving is stopped.

10. The reverse control device for a coupled vehicle according to claim 1, wherein: The automatic reverse driving is provided with a function of adjusting the travel speed by the depression amount of the brake pedal of the towing vehicle during the automatic reverse driving for moving the coupled vehicle toward a target position, and stopping the automatic reverse driving when the depression amount of the brake pedal becomes equal to or greater than a predetermined value.

11. The reverse control device for a coupled vehicle according to claim 10, wherein: When the coupled vehicle reaches the vicinity of the target position, the predetermined value of the depression amount is made larger than that before the coupled vehicle reaches the vicinity of the target position.

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