Reverse control device for articulated vehicles

Abstract

To provide a reverse control device capable of starting reversing a coupled vehicle under automated driving only when conditions for proper automated driving are satisfied, and stably performing the reversing of the coupled vehicle under the automated driving.SOLUTION: An automated driving ECU 71 functioning as a reverse control device is installed in a towing vehicle 11 of a coupled vehicle 1 in which a vehicle 12 to be towed is coupled to the towing vehicle 11; and controls the towing vehicle 11 during automated reverse driving in which the coupled vehicle 1 is caused to reverse by automated driving. The automated driving ECU 71 starts automated reverse driving when towing reverse start conditions have been satisfied, these conditions including a speed of the towing vehicle 11 being equal to or less than a predetermined value and steering torque of the towing vehicle 11 being equal to or less than a predetermined value.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a reverse control device for a coupled vehicle that is used in a coupled vehicle in which a towed vehicle is towed by a towing vehicle and controls the towing vehicle when the coupled vehicle reverses.

Background Art

[0002] In a coupled vehicle in which a towed vehicle is towed by a towing vehicle, when moving forward, the towed vehicle follows the towing vehicle and travels, so the driving operation is relatively easy. However, when reversing the coupled vehicle, for example, when parking in a parking space, the towed vehicle does not always move in the direction corresponding to the steering angle of the towing vehicle. Therefore, especially when the driver of the towing vehicle is not familiar with driving the coupled vehicle, the driving operation is difficult. For this reason, devices and methods for assisting the driving operation when the coupled vehicle reverses have been proposed. For example, the automatic or semi-automatic driving system described in Patent Document 1 can issue operation commands to the system by voice such as "reverse 10 feet", "stop", "turn 90 degrees to the right", etc. issued by an operator in the vehicle cabin.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a reverse control device capable of automatically reversing a coupled vehicle, depending on the state of the towing vehicle at the start of reverse, it may not be possible to appropriately guide the coupled vehicle to the destination by automatic driving. Therefore, an object of the present invention is to provide a reverse control device that starts the reverse of the coupled vehicle by automatic driving only when the conditions for appropriately performing automatic driving are met and can stably perform the reverse of the coupled vehicle by automatic driving.

Means for Solving the Problems

[0005] To achieve the above objective, the present invention provides a reverse control device for a coupled vehicle, which is mounted on the towing vehicle of a coupled vehicle in which a towed vehicle is coupled to a towing vehicle equipped with a steering device, and controls the towing vehicle during automatic reverse driving, wherein the automatic reverse driving is started when all start conditions are met, including the vehicle speed of the towing vehicle being below a predetermined value and the steering torque of the towing vehicle being below a predetermined value. To provide. [Effects of the Invention]

[0006] According to the reverse control device of the present invention, the reverse operation of the coupled vehicle by automatic driving is initiated only when the conditions for proper automatic driving are met, and the reverse operation of the coupled vehicle by automatic driving can be performed stably. [Brief explanation of the drawing]

[0007] [Figure 1] This is an overhead view showing a connected vehicle according to the first embodiment of the present invention. [Figure 2] This is a schematic diagram showing an example of a hitch angle sensor configuration. [Figure 3] This is a schematic diagram showing an example of the configuration of a towing vehicle. [Figure 4] This is a control block diagram showing the configuration of a control system consisting of multiple ECUs. [Figure 5] This flowchart shows an example of the process performed by an autonomous driving ECU. [Modes for carrying out the invention]

[0008] [First Embodiment] A first embodiment of the present invention will be described with reference to the drawings. The embodiments described below are shown as preferred specific examples for carrying out the present invention, and some parts specifically illustrate various technically preferable technical matters, but the technical scope of the present invention is not limited to these specific embodiments.

[0009] Figure 1 is an overhead view showing a coupled vehicle 1 according to this embodiment. The coupled vehicle 1 has a towing vehicle 11 and a towed vehicle 12, and when moving forward, the towed vehicle 12 is towed by the towing vehicle 11. The towing vehicle 11 and the towed vehicle 12 are connected by a towing-side coupling member 13 on the towing vehicle 11 side and a towed-side coupling member 14 on the towed vehicle 12 side. In Figure 1, as an example, the towed vehicle 12 is shown as a box-shaped camper van, but the towed vehicle 12 is not limited to this and may be, for example, a boat trailer carrying a boat or a cargo trailer.

[0010] The towing-side connecting member 13 is provided with a spherical hitch ball 131, and the towed-side connecting member 14 has a coupler 141 that covers the hitch ball 131, a latch mechanism 142 that prevents the coupler 141 from coming off the hitch ball 131 by operating a lever 142a, and a rod-shaped tongue 143 to which the coupler 141 is fixed at the tip. The towed-side connecting member 14 is pivotable about the hitch point 131a, which is the center point of the hitch ball 131.

[0011] In Figure 1, the centerline 11a of the towing vehicle 11 along its longitudinal direction and the centerline 12a of the towed vehicle 12 along its longitudinal direction are shown by dashed lines. When the coupled vehicle 1 is viewed from above, the centerline 11a of the towing vehicle 11 and the centerline 12a of the towed vehicle 12 along its longitudinal direction intersect at the hitch point 131a. The angle θh between the centerline 11a of the towing vehicle 11 and the centerline 12a of the towed vehicle 12 along its longitudinal direction is the hitch angle, which indicates the inclination angle of the towed vehicle 12 relative to the towing vehicle 11. The hitch angle is detected by a hitch angle sensor.

[0012] Figure 2 is a schematic diagram showing an example configuration of the hitch angle sensor 81. The hitch angle sensor 81 has a gear-shaped magnetic body 811 fixed to the coupler 141 and a magnetic sensor 812 attached to the towing-side connecting member 13, with the magnetic sensor 812 facing the outer circumference of the magnetic body 811. The strength of the magnetic field detected by the magnetic sensor 812 changes as the magnetic body 811 rotates relative to the magnetic sensor 812, so it is possible to detect the hitch angle by this change in the strength of the magnetic field.

[0013] Figure 3 is a schematic diagram showing an example configuration of the towing vehicle 11. The towing vehicle 11 is equipped with left and right front wheels 21 and 22 which are steerable wheels and left and right rear wheels 23 and 24 which are not steerable wheels, and has an automatic driving function that enables automatic driving by automatically steering the left and right front wheels 21 and 22 when the towed vehicle 1 is reversing. In this embodiment, the towing vehicle 11 is an electric vehicle that uses a drive motor 30 that generates driving force by receiving an electric current as its drive source. The towing vehicle 11 is equipped with a battery 31 and an inverter 32, and the DC current output from the battery 31 is converted into AC current by the inverter 32 and supplied to the drive motor 30. When the driver operates the towing vehicle 11, the magnitude of the current supplied to the drive motor 30 changes according to the amount the accelerator pedal 111 is pressed.

[0014] The drive motor 30 is, for example, an IPM (Interior Permanent Magnet) synchronous motor comprising a stator that generates a rotating magnetic field by an alternating current supplied from an inverter 32, and a rotor that rotates relative to the stator, with multiple permanent magnets embedded in the rotor. However, an electric motor with a different configuration may be used as the drive motor 30. The drive source of the towing vehicle 11 may be an internal combustion engine, or it may be a hybrid system combining an engine and an electric motor.

[0015] The torque output from the drive motor 30 is transmitted from the pinion gear 301 fixed to the output rotating shaft 300 of the drive motor 30 to the ring gear 302 and 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 gear shaft 332 fixed to the differential case 331, a plurality of pinion gears 333 pivotally supported on the pinion gear shaft 332, and a pair of side gears 334, 335 that mesh with the plurality of pinion gears 333 with their gear axes perpendicular to each other.

[0016] One side gear 334 of the differential device 33 is connected to the left drive shaft 34, and the other side gear 335 is connected to the right drive shaft 35. 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.

[0017] 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 which is steered by the driver of the towing vehicle 11, a steering shaft 41 connected to the steering wheel 40, a rack shaft 42 which moves back and forth in the vehicle width direction by the rotation of the steering shaft 41, tie rods 44 which are pivotably 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 steering assist force to assist the steering operation of the steering wheel 40 when the driver steers the steering wheel 40 in manual driving, and functions as an actuator that moves the rack shaft 42 to steer the left and right front wheels 21 and 22 in automatic driving.

[0018] The front wheels 21, 22 and the rear wheels 23, 24 are each equipped with rubber tires 212, 222, 232, 242 on metal wheels 211, 221, 231, 241. Also, brake devices 51 to 54 are respectively provided corresponding to the front wheels 21, 22 and the rear wheels 23, 24. The brake devices 51 to 54 generate a braking force with a strength corresponding to the amount of depression of the brake pedal 112.

[0019] The towing vehicle 11 is equipped with a plurality of cameras for photographing the surroundings of the towed vehicle 1. In the present embodiment, as these plurality of cameras, a front camera 61 for photographing the front of the towing vehicle 11, a rear camera 62 for photographing the rear of the towing vehicle 11, a left side camera 63 for photographing the left side of the towing vehicle 11, and a right side camera 64 for photographing the right side of the towing vehicle 11 are mounted. The front camera 61 is arranged at the front end of the towing vehicle 11, and the rear camera 62 is arranged at the rear end of the towing vehicle 11. The left side camera 63 and the right side camera 64 are respectively arranged on the left and right side mirrors 113, 114.

[0020] The image information of the images photographed 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 each of these cameras 61 to 64 to grasp the situation around the towed vehicle 1, and recognizes it if there is an obstacle. Note that a camera may also be mounted on the towed vehicle 12, and the image processing device 60 may recognize the obstacles around the towed vehicle 1 including the image information of this camera.

[0021] Also, the towing vehicle 11 is provided with a shift lever 115. The driver can shift the shift lever 115 to a parking range that makes the towing vehicle 11 immovable, a reverse range when reversing, a neutral range, and a drive range when moving forward.

[0022] Furthermore, the towing vehicle 11 is equipped with a touch panel display (TPD) 116 in a position accessible to the driver. The touch panel display 116 is used as a display for the car navigation system, as well as to display images of the surroundings of the coupled vehicle 1 created by the image processing device 60. The image processing device 60, for example, synthesizes an overhead image of the surroundings of the coupled vehicle 1 from image information obtained from each of the cameras 61 to 64 and displays it on the touch panel display 116.

[0023] Furthermore, the towing vehicle 11 is equipped with a start button 117 operated by the driver. The start button 117 is used to initiate 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 to this; a virtual button displayed on the touch panel display 116 may also be used as the start button.

[0024] Figure 4 is a control block diagram showing the configuration of a control system 7 consisting of multiple ECUs (Electronic Control Units) mounted on a towing vehicle 11. The control system 7 includes an automatic driving ECU 71, a drive ECU 72, a steering ECU 73, and a braking ECU 74. Each of the ECUs 71 to 74 is connected to an in-vehicle network 70 such as CAN (Controller Area Network) or LIN (Local Interconnect Network), enabling bidirectional communication.

[0025] Each ECU 71-74 can acquire detection results from multiple sensors located in various parts of the towing vehicle 11 via the in-vehicle network 70. The multiple sensors include a hitch angle sensor 81 that detects the hitch angle between the towing vehicle 11 and the towed vehicle 12, a wheel speed sensor 82 that detects the rotational speed of the front wheels 21, 22 and the rear wheels 23, 24, a voltage sensor 83 that detects the voltage of the battery 31, a steering angle sensor 84 that detects the steering angle of the steering wheel 20, a steering torque sensor 85 that detects the steering torque applied to the steering wheel 20, an EPS temperature sensor 86 that detects the temperature of the electric power steering system 45, an accelerator pedal sensor 87 that detects the amount of depression of the accelerator pedal 111, a brake pedal sensor 88 that detects the amount of depression of the brake pedal 112, and a shift position sensor 89 that detects the position of the shift lever 115.

[0026] During manual operation, when the driver operates the towing vehicle 11, the drive ECU 72 outputs a PWM (Pulse Width Modulation) signal to the inverter 32 according to the detection results of the accelerator pedal sensor 87 and the shift position sensor 89, thereby controlling the drive motor 30. The steering ECU 73 controls the electric power steering system 45 according to the detection results of the steering angle sensor 84 and the steering torque sensor 85. The braking ECU 74 controls the brake systems 51-54 according to the detection results of the brake pedal sensor 88 and the wheel speed sensor 82.

[0027] 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 is reversing. The automatic driving ECU 71 can send commands to the drive ECU 72, steering ECU 73, and braking ECU 74 during automatic driving to perform various operations. Specifically, it can send a drive force command signal to the drive ECU 72, causing the drive motor 30 to generate a drive force corresponding to the drive force command signal. The automatic driving ECU 71 can also send a steering angle command signal to the steering ECU 73, causing the front wheels 21 and 22 to be steered to an angle corresponding to the steering angle command signal. Furthermore, the automatic driving ECU 71 can send a braking force command signal to the braking ECU 74, causing the brake devices 51 to 54 to generate a braking force corresponding to the braking force command signal.

[0028] Furthermore, the autonomous driving ECU 71 can communicate with the image processing device 60 and obtain information on the presence or absence of obstacles recognized by the image processing device 60, as well as information on the location and size of obstacles if they exist. In addition, the autonomous driving ECU 71 can obtain information indicating the operation status of the start button 117.

[0029] The automated driving ECU 71 starts towing reverse control to reverse the towed vehicle 1 by automated driving when all of the multiple conditions for starting towing reverse are met. Hereinafter, automated driving to reverse the towed vehicle 11 will be referred to as automated reverse driving. Hereinafter, automated driving includes not only driving the towed vehicle 11 without the driver of the towed vehicle 11 operating the steering wheel 20, accelerator pedal 111, or brake pedal 112, but also so-called driver assistance in which the driver does not operate the steering wheel 20 but operates the accelerator pedal 111 and brake pedal 112.

[0030] The person who initiates the automatic reverse operation of the coupled vehicle 1 is not limited to the driver of the towing vehicle 11; it may also be, for example, a passenger in the towing vehicle 11 or a person riding in the towed vehicle 12, or even a person who is not riding in either the towing vehicle 11 or the towed vehicle 12. Hereinafter, the person who initiates the automatic reverse operation will be referred to as the operator.

[0031] The operator specifies at least one of the direction of travel and the target position during automatic reverse operation. This specification can be made, for example, using the touch panel display 116, but the direction of travel and the target position of the coupled vehicle 1 may also be specified by operating an operating device provided on the towing vehicle 11 or the towed vehicle 12, or by operating the operator's wireless information terminal.

[0032] The multiple conditions for initiating towing and reversing include the following conditions 1 through 12. The autonomous driving ECU 71 initiates towing and reversing control when all of conditions 1 through 12 are met.

[0033] The first condition is that the speed of the towing vehicle 11 is below a predetermined value. The automatic driving ECU 71 can determine the speed of the towing vehicle 11, for example, based on the detection result of the wheel speed sensor 82. The predetermined value in this first condition is a small value such that the first condition is satisfied only when the towing vehicle 11 is substantially stationary. In other words, the first condition can also be rephrased as the towing vehicle 11 being stationary.

[0034] The second condition is that the accelerator pedal 111 is not depressed. Based on the detection result of the accelerator pedal sensor 87, the autonomous driving ECU 71 can determine that the second condition is met if the amount of depression of the accelerator pedal 111 is less than or equal to a predetermined value. The predetermined value in this second condition is a value less than the amount of depression set as play in the accelerator pedal 111. Here, "play" refers to the range in which the depression operation of the accelerator pedal 111 does not affect the control of the drive motor 30, where the amount of depression is shallow.

[0035] The third condition is that the towing vehicle 11 is being braked. The automatic driving ECU 71 can determine that the third condition is met, for example, based on the detection result of the brake pedal sensor 88, if the amount of depression of the brake pedal 112 is greater than or equal to a predetermined value. Furthermore, the third condition can be determined to be met not only when the brakes (foot brakes) are activated by the depression of the brake pedal 112, but also when the towing vehicle 11 is being braked by, for example, the parking brake.

[0036] The fourth condition is that the steering torque is below a predetermined value. The autonomous driving ECU 71 can determine whether the fourth condition is met based on the detection result of the steering torque sensor 85. The predetermined value in this fourth condition is a small value such that the fourth condition is met only when the steering wheel 20 is not being steered. In other words, the fourth condition can also be rephrased as the steering wheel 20 not being steered.

[0037] The fifth condition is that the shift position of the shift lever 115 is in the reverse range. The autonomous driving ECU 71 can determine whether the fifth condition is met based on the detection result of the shift position sensor 89.

[0038] The sixth condition is that the drive ECU 72, steering ECU 73, and braking ECU 74 are operating normally. The automatic driving ECU 71 can determine that the sixth condition is met if it communicates normally with the drive ECU 72, steering ECU 73, and braking ECU 74, and the information obtained from the drive ECU 72, steering ECU 73, and braking ECU 74 does not contain any information indicating that an abnormality has occurred in any of the ECUs 72-74.

[0039] The seventh condition is that no abnormalities occur in any of the controlled devices of the drive ECU 72, steering ECU 73, and braking ECU 74. Here, the controlled devices of the drive ECU 72 are the drive motor 30 and the inverter 32. The controlled device of the steering ECU 73 is the electric power steering device 45. The controlled devices of the braking ECU 74 are the brake devices 51 to 54. The automatic driving ECU 71 can determine whether the seventh condition is met based on information obtained through communication with, for example, the drive ECU 72, steering ECU 73, and braking ECU 74. For example, if the information obtained from the steering ECU 73 includes information indicating overheating of the electric power steering device 45, the seventh condition will not be met.

[0040] The eighth condition is that the voltage of the battery 31 is within the appropriate range. The autonomous driving ECU 71 can determine whether the eighth condition is met based on the detection result of the voltage sensor 83.

[0041] The ninth condition is that each of the sensors 81 to 89 described above is functioning normally. The automatic driving ECU 71 determines that the ninth condition is not met if, for example, the detection result of any of the sensors 81 to 89 is outside the normal range. Furthermore, if the steering angle sensor 84 is not an absolute encoder capable of detecting the absolute position of the steering angle, but rather an incremental encoder that outputs a pulse signal, the automatic driving ECU 71 also determines that the ninth condition is not met if the offset adjustment of the neutral position of the steering wheel 20 is not completed. The automatic driving ECU 71 also determines that the ninth condition is not met if the offset adjustment of the hitch angle detected by the hitch angle sensor 81 is not completed. Note that the offset adjustment of the neutral position of the steering wheel 20 and the offset adjustment of the hitch angle can be performed, for example, by setting the steering angle and hitch angle to zero when the coupled vehicle 1 travels a predetermined distance in a straight line in the forward direction.

[0042] Furthermore, the autonomous driving ECU 71 also determines that the ninth condition is not met if it determines that the hitch angle has not been correctly detected by the hitch angle sensor 81. In other words, the ninth condition includes the fact that the hitch angle between the towing vehicle 11 and the towed vehicle 12 has been correctly detected by the hitch angle sensor 81. Whether or not the hitch angle has been correctly detected by the hitch angle sensor 81 can be determined, for example, by comparing the images taken by the rear camera 62, the left-side camera 63, and the right-side camera 64 with the values ​​detected by the hitch angle sensor 81. Specifically, for example, if the hitch angle detected by the hitch angle sensor 81 is 0°, but the images from the rear camera 62, the left-side camera 63, and the right-side camera 64 detect that the towed vehicle 12 is tilted horizontally relative to the towing vehicle 11, then it is determined that the hitch angle has not been correctly detected by the hitch angle sensor 81.

[0043] The tenth condition is that no obstacles that would hinder reverse driving are detected by the images from the front camera 61, rear camera 62, left-side camera 63, and right-side camera 64. Based on the information obtained from the image processing device 60, the automated driving ECU 71 determines that the tenth condition is met if it determines that there are no obstacles that would hinder reverse driving around the towing vehicle 11 or towed vehicle 12 in the direction of travel specified by the operator, or around the towing vehicle 11 or towed vehicle 12 along the path to the target position specified by the operator. If it determines that such obstacles exist, it determines that the tenth condition is not met.

[0044] The eleventh condition is that, with all of the first to tenth conditions met, an instruction operation has been made by the operator to initiate automatic driving. This instruction operation can be performed, for example, by operating the automatic reverse driving start button 117 as described above, but it may also be performed by operating an operating device provided on the towing vehicle 11 or the towed vehicle 12, or by operating the operator's wireless information terminal, to instruct the automatic driving ECU 71 to start towing reverse control.

[0045] 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, for example, by determining whether or not it has obtained hitch angle information from the hitch angle sensor 81. Alternatively, the automatic driving ECU 71 may determine whether or not the towed vehicle 12 is connected to the towing vehicle 11 based on information obtained from the image processing device 60, particularly based on the image from the rear camera 62.

[0046] Furthermore, if conditions 1 through 11 are met but condition 12 is not met, the automatic driving ECU 71 initiates non-towing reverse control to reverse the towing vehicle 11, which is not coupled to the towed vehicle 12, by automatic driving. In other words, if the towing vehicle 11 is not coupled to the towing vehicle 12 when the instruction operation for condition 11 is made, the automatic driving ECU 71 reverses only the towing vehicle 11 by automatic driving through non-towing reverse control.

[0047] The automated driving ECU 71 starts towing reverse control when all of the first to twelfth conditions are met. During towing reverse control, the automated driving ECU 71 calculates a target hitch angle to move the towed vehicle 1 toward the direction of travel or target position specified by the operator, and sends a command to the steering ECU 73 so that the actual hitch angle matches this target value, causing the steering device 4 to steer the left and right front wheels 21 and 22. However, when the first to twelfth conditions are met, the towed vehicle 11 is braked by the third condition, so the towed vehicle 1 begins to move backward after this braking state is released. The speed of the towed vehicle 11 during reverse movement may be controlled by the automated driving ECU 71, or it may be adjusted by the driver operating the accelerator pedal 111 or the brake pedal 112.

[0048] Furthermore, after initiating towing reverse control, the autonomous driving ECU 71 stops the towing reverse control and brings the coupled vehicle 1 to a stop if any of the 4th to 10th conditions are not met. The autonomous driving ECU 71 also stops the towing reverse control if any of the 1st to 3rd stopping conditions described below are met.

[0049] The first stopping condition is that the brake pedal 112 is pressed with sufficient force to stop the towing vehicle 11. Specifically, the towing reverse control is stopped when the amount of pressure applied to the brake pedal 112 exceeds, for example, the predetermined value of the third condition. This allows the driver of the towing vehicle 11 to immediately stop the vehicle by pressing the brake pedal 112 firmly if they sense any danger in the surrounding environment. However, if the towing vehicle 11 is near the target position, the driver may press the brake pedal 112 to adjust the speed, so the predetermined value of the amount of pressure applied to the brake pedal 112 to stop the towing reverse control is set to be greater than the predetermined value of the third condition.

[0050] In other words, the autonomous driving ECU 71 can adjust the driving speed by the amount the brake pedal 112 is pressed during automatic reverse driving to move the coupled vehicle 1 toward the target position, and has a function to stop automatic reverse driving when the amount the brake pedal 112 is pressed exceeds a predetermined value, and when the coupled vehicle 1 is near the target position, the predetermined value of the amount the brake pedal 112 is pressed is increased to be greater than before the coupled vehicle 1 reached the vicinity of the target position.

[0051] The second stopping condition is that the operator instructs the automatic driving to stop, or that the vehicle has reached a target position designated by the operator. The operator can instruct the automatic driving to stop, for example, by operating the start button 117 again. Alternatively, the operator may instruct the automatic driving to stop by operating a control device provided on the towing vehicle 11 or the towed vehicle 12, or by operating the operator's wireless information terminal.

[0052] The third stopping condition is that the hitch angle between the towing vehicle 11 and the towed vehicle 12 exceeds a predetermined value due to slippage of the towing vehicle 11 or the towed vehicle 12, for example, due to crosswinds or road slope. This predetermined value of the hitch angle is an angle such that the jackknife phenomenon occurs. Here, the jackknife phenomenon refers to a phenomenon in which the hitch angle increases even when the towing vehicle 11 is reversed, but the towed vehicle 12 does not reverse. In such a case, the driver manually moves the towing vehicle 11 forward to reduce the hitch angle, and then the operator restarts the towing reverse control by the automatic driving ECU 71.

[0053] Furthermore, the automatic driving ECU 71 stops the non-towing reverse control of the towing vehicle 11 if any of the 4th to 10th conditions are not met, or if the 1st or 2nd stop condition described above is met, after initiating non-towing reverse control of the towing vehicle 11 which is not coupled with the towed vehicle 12.

[0054] Figure 5 is a flowchart showing an example of the process performed by the autonomous driving ECU 71. The autonomous driving ECU 71 repeatedly executes the process shown in this flowchart at a predetermined control cycle.

[0055] The automated driving ECU 71 determines whether or not towing reverse control is being performed (step S1), and if towing reverse control is being performed, determines whether or not the fourth to tenth conditions are met (step S2). If the result of the determination in step S2 is Yes, the automated driving ECU 71 determines whether or not any of the first to third stop conditions are not met (step S3), and if the result of this determination is Yes, it continues towing reverse control (step S4). On the other hand, if the result of the determination in step S2 or step S3 is No, the automated driving ECU 71 stops towing reverse control (step S5).

[0056] Furthermore, if the result of the determination in step S1 is No, the autonomous driving ECU 71 determines whether or not non-towing reverse control is being performed (step S6), and if non-towing reverse control is being performed, it determines whether or not the 4th to 10th conditions are met (step S7). If the result of the determination in step S7 is Yes, the autonomous driving ECU 71 determines whether or not the 1st stop condition and the 2nd stop condition are not met (step S8), and if the result of this determination is Yes, it continues non-towing reverse control (step S9). On the other hand, if the result of the determination in step S7 or step S8 is No, the autonomous driving ECU 71 stops non-towing reverse control (step S10).

[0057] Furthermore, if the result of the determination in step S6 is No, the autonomous driving ECU 71 determines whether the first to eleventh conditions are met (step S11), and if the result of this determination is Yes, it determines whether the twelfth condition is met (step S12). If the result of the determination in step S12 is Yes, the autonomous driving ECU 71 starts towing reverse control (step S13), and if the result of the determination in step S12 is No, it starts non-towing reverse control (step S14). On the other hand, if the result of the determination in step S11 is No, the process shown in the flowchart in Figure 5 is terminated.

[0058] According to the first embodiment described above, the automatic reverse operation of the coupled vehicle 1 can be stably performed by initiating the reverse operation of the coupled vehicle 1 only when all of the first to twelfth conditions are met.

[0059] [Second Embodiment] Next, a second embodiment of the present invention will be described. In the first embodiment described above, the operator's instruction to start automatic reverse driving was described by operating the start button 117, operating an operating device provided on the towing vehicle 11 or the towed vehicle 12, or operating the operator's wireless information terminal. In this embodiment, however, the automatic driving ECU 71 starts automatic reverse driving in response to an instruction operation by the driver of the towing vehicle 11 by operating the accelerator pedal 111. More specifically, based on the detection result of the accelerator pedal sensor 87, the automatic driving ECU 71 starts automatic reverse driving when the amount of depression of the accelerator pedal 111 is greater than or equal to a predetermined value.

[0060] Furthermore, while the first embodiment described above included the condition that the accelerator pedal 111 is not depressed (second condition) as a condition for initiating towed reverse control or non-towed reverse control, this condition is excluded in this embodiment. Also, in this embodiment, in order to clearly distinguish it from driving operations during manual driving by the driver (non-automated driving), the towing vehicle 11 is in automatic driving mode as an essential condition for initiating towed reverse control or non-towed reverse control. In other words, in this embodiment, the 11th condition described above means that the accelerator pedal 111 of the towing vehicle 11 has been operated while the first condition and conditions 3 through 10 are all met and the towing vehicle 11 is in automatic driving mode.

[0061] The determination of whether or not the vehicle is in automatic driving mode can be made, for example, based on the setting of a switch that toggles between manual driving mode and automatic driving mode. Alternatively, the determination of whether or not the vehicle is in automatic driving mode may be made if the operator has set a target position or a direction of travel.

[0062] According to this second embodiment, in addition to the effects of the first embodiment described above, operation of the start button 117 is not required when initiating reverse driving by automatic driving. Therefore, for example, when adjusting the vehicle speed during reverse driving by the amount the driver depresses the accelerator pedal 111, the burden on the driver can be reduced.

[0063] (Note) Although the present invention has been described above based on the first and second embodiments, these embodiments do not limit the invention as defined in the claims. It should also be noted that not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention. Furthermore, the present invention can be implemented by omitting some components, or by adding or substituting components, without departing from its spirit. [Explanation of Symbols]

[0064] 1...Twin-car train 4...Steering device 11...Towing vehicle 12...Towed vehicle 45…Electric power steering system 61…Front camera 62...Rear camera 63...Left side camera 64...Right-side camera 71...Automated driving ECU (reverse control unit) 81...Hitch angle sensor 111...Accelerator pedal 112...Brake pedal

Claims

1. A reverse control device mounted on the towing vehicle of a coupled vehicle in which a towed vehicle is coupled to a towing vehicle equipped with a steering device, which controls the towing vehicle during automatic reverse driving in which the coupled vehicle is driven backward by automatic driving, The automatic reverse operation is started when all the starting conditions are met, including the fact that the vehicle speed of the towing vehicle is below a predetermined value and the steering torque of the towing vehicle is below a predetermined value. The aforementioned start conditions include the fact that the vehicle speed of the towing vehicle is below a predetermined value and the steering torque of the towing vehicle is below a predetermined value, and the operator has given an instruction to start the automatic reverse operation. The aforementioned instruction operation is the operation of the accelerator pedal of the towing vehicle. Reverse control device for articulated vehicles.

2. A reverse control device mounted on the towing vehicle of a coupled vehicle in which a towed vehicle is coupled to a towing vehicle equipped with a steering device, which controls the towing vehicle during automatic reverse driving in which the coupled vehicle is driven backward by automatic driving, The automatic reverse operation is started when all the starting conditions are met, including the fact that the vehicle speed of the towing vehicle is below a predetermined value and the steering torque of the towing vehicle is below a predetermined value. The aforementioned start conditions include the fact that the vehicle speed of the towing vehicle is below a predetermined value and the steering torque of the towing vehicle is below a predetermined value, and the operator has given an instruction to start the automatic reverse operation. When the aforementioned instruction operation is performed, if the towing vehicle is not connected to the towing vehicle, the towing vehicle alone will be reversed by automatic driving. Reverse control device for articulated vehicles.

3. A reverse control device mounted on the towing vehicle of a coupled vehicle in which a towed vehicle is coupled to a towing vehicle equipped with a steering device, which controls the towing vehicle during automatic reverse driving in which the coupled vehicle is driven backward by automatic driving, The automatic reverse operation is started when all the starting conditions are met, including the fact that the vehicle speed of the towing vehicle is below a predetermined value and the steering torque of the towing vehicle is below a predetermined value. The aforementioned starting condition includes the fact that no obstacles that would hinder the reverse movement of the coupled vehicle are detected by images taken by a camera surrounding the coupled vehicle. Reverse control device for articulated vehicles.

4. A reverse control device mounted on the towing vehicle of a coupled vehicle in which a towed vehicle is coupled to a towing vehicle equipped with a steering device, which controls the towing vehicle during automatic reverse driving in which the coupled vehicle is driven backward by automatic driving, The automatic reverse operation is started when all the starting conditions are met, including the fact that the vehicle speed of the towing vehicle is below a predetermined value and the steering torque of the towing vehicle is below a predetermined value. The aforementioned starting condition includes the fact that the hitch angle between the towing vehicle and the towed vehicle is correctly detected by the hitch angle sensor. The camera image taken around the aforementioned coupled vehicle is used to determine whether or not the hitch angle is correctly detected by the hitch angle sensor. Reverse control device for articulated vehicles.

5. A reverse control device mounted on the towing vehicle of a coupled vehicle in which a towed vehicle is coupled to a towing vehicle equipped with a steering device, which controls the towing vehicle during automatic reverse driving in which the coupled vehicle is driven backward by automatic driving, The automatic reverse operation is started when all the starting conditions are met, including the fact that the vehicle speed of the towing vehicle is below a predetermined value and the steering torque of the towing vehicle is below a predetermined value. During the automatic reverse operation that moves the coupled vehicle toward the target position, the travel speed can be adjusted by the amount the brake pedal of the towing vehicle is pressed, and the automatic reverse operation is stopped when the amount the brake pedal is pressed exceeds a predetermined value. Reverse control device for articulated vehicles.

6. When the coupled vehicle has reached the vicinity of the target position, the predetermined value of the amount of detour is made greater than before the coupled vehicle reached the vicinity of the target position. The reverse control device for a coupled vehicle according to claim 5.

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