Towing assistance device

Abstract

To easily generate a path regardless of a positional relation between a towing vehicle and a target stop position and regardless of a parking angle.SOLUTION: A towing assistance device according to an embodiment, which is a towing assistance device for assisting reverse parking of a towing vehicle that tows a to-be-towed vehicle, comprises: a detection unit configured to detect a parking area having an entrance on a lateral side of the towing vehicle; and a calculation unit configured to generate a target path including a forward path and a backward path for the towing vehicle, based on a default stop position and a default path set in advance. The calculation unit calculates: a target stop position determined based on the parking region; a first amount of deviation from the default stop position in a fore-aft direction of the towing vehicle; and a second amount of deviation in the fore-aft direction of the towing vehicle, which is caused according to a parking angle when the towing vehicle is parked in the parking region. The calculation unit generates the forward path, based on the sum of the amounts of first and second deviations.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a traction assist device. [Background technology]

[0002] There are known devices that provide towing assistance to a towing vehicle, such as a tractor, that tows a towed vehicle, such as a trailer. For example, when towing a towed vehicle in reverse, the towing assistance device calculates a target route for the towed vehicle in advance and controls the towing vehicle so that the towed vehicle moves along the calculated target route.

[0003] For example, in the technology of Patent Document 1, multiple reverse route patterns for the towed vehicle are stored, and in towing assistance, multiple reverse trajectories for the towing vehicle are generated based on these reverse route patterns, and an appropriate reverse trajectory is selected from among them. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-044216 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the technology of Patent Document 1 mentioned above, multiple routes must be generated depending on the positional relationship between the towing vehicle and the target stopping position at the time towing assistance begins, which increases calculation costs and makes route generation more difficult depending on the parking angle.

[0006] The present invention has been made in consideration of the above, and aims to provide a towing assistance device that can easily generate a route regardless of the positional relationship between the towing vehicle and the target stopping position or the parking angle. [Means for solving the problem]

[0007] A towing assistance device according to an embodiment is a towing assistance device that assists a towing vehicle that tows a towed vehicle in backing into parking, and includes a detection unit that detects a parking area having an entrance on the side of the towing vehicle, and a calculation unit that generates a target route including a forward route and a reverse route for the towing vehicle based on a preset default stopping position and default route. The calculation unit calculates the amount of deviation between the target stopping position determined based on the parking area and the default stopping position, which is a first amount of deviation in the fore-and-aft direction of the towing vehicle and a second amount of deviation in the fore-and-aft direction of the towing vehicle that occurs depending on the parking angle when the towing vehicle is parked in the parking area, and generates the forward route based on the sum of the first and second amounts of deviation.

[0008] The towing assistance device of the embodiment can easily generate a route regardless of the positional relationship between the towing vehicle and the target stopping position or the parking angle. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view showing a tractor and a trailer according to an embodiment. [Figure 2] FIG. 2 is a top view showing the tractor and trailer according to the embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of the configuration of the traction assist system provided in the tractor according to the embodiment. [Figure 4] FIG. 4 is a block diagram illustrating an example of a functional configuration of the traction assist device according to the embodiment. [Figure 5] FIG. 5 is an explanatory diagram showing an example of an operation of the traction assist device according to the embodiment to generate a forward route among the target route. [Figure 6] FIG. 6 is an explanatory diagram showing an example of the operation of the traction assist device according to the embodiment to generate a forward route among the target route. [Figure 7] FIG. 7 is an explanatory diagram showing an example of the operation of the traction assist device according to the embodiment to generate a forward route among the target route. [Figure 8]FIG. 8 is an explanatory diagram showing an example of the operation of the traction assist device according to the embodiment to generate a forward route among the target routes. [Figure 9] FIG. 9 is an explanatory diagram showing an example of the operation of the traction assist device according to the embodiment to generate a forward route among the target routes. [Figure 10] FIG. 10 is an explanatory diagram showing an example of the operation of the traction assist device in the reverse parking assistance according to the embodiment. [Figure 11] FIG. 11 is an explanatory diagram showing an example of the operation of the traction assist device in the reverse parking assistance according to the embodiment. [Figure 12] FIG. 12 is a flowchart illustrating an example of a procedure for generating a target route for back-up parking by the traction assist device according to the embodiment. [Figure 13] FIG. 13 is an explanatory diagram showing an example of an operation of the traction assist device according to the modified embodiment to generate a forward path of the target path. [Figure 14] FIG. 14 is an explanatory diagram showing an example of an operation of the traction assist device according to the modified embodiment to generate a forward route of the target route. [Figure 15] FIG. 15 is a flowchart showing an example of a procedure for generating a target route for back-in parking by a traction assist device according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a traction assist device according to the present invention will be described in detail with reference to the accompanying drawings.

[0011] (Example of tractor and trailer configuration) Fig. 1 is a side view showing a tractor 10 and a trailer 20 according to an embodiment. Fig. 2 is a top view showing the tractor 10 and the trailer 20 according to an embodiment. In Figs. 1 and 2, the tractor 10 is used as a reference, and the left side of the paper is the front (forward traveling direction) and the right side of the paper is the rear (reverse traveling direction). The tractor 10 is an example of a towing vehicle, and the trailer 20 is an example of a towed vehicle that is towed by a towing vehicle such as the tractor 10.

[0012] The tractor 10 may be, for example, a vehicle such as an internal combustion engine automobile using an internal combustion engine (engine) as a drive source, or may be a vehicle such as an electric vehicle or fuel cell automobile using an electric motor (motor) as a drive source, or may be a vehicle such as a hybrid automobile using both of these as a drive source. Therefore, the tractor 10 can be equipped with various transmissions, and various devices, systems, parts, etc. required to drive the internal combustion engine or electric motor.

[0013] The tractor 10 may also be a sport utility vehicle (SUV) as shown in FIG. 1, a so-called "pickup truck" with a cargo bed at the rear of the vehicle, or a regular passenger car.

[0014] The tractor 10 has four wheels 14, including, for example, a pair of front wheels 14F and a pair of rear wheels 14R. The tractor 10 of this embodiment is a rear-wheel drive vehicle driven by, for example, the rear wheels 14R. However, the method, number, layout, etc. of driving the wheels 14 of the tractor 10 can be set in various ways.

[0015] Imaging units 12 are provided at the front end, rear end, and left and right side mirrors of the tractor 1. The imaging units 12 are digital cameras incorporating imaging elements such as a CCD (Charge Coupled Device) or a CIS (CMOS Image Sensor), and capture images of the surroundings of the tractor 10 at a predetermined frame rate and output the captured images as image data.

[0016] The imaging unit 12 provided at the rear end of the tractor 10 sequentially captures images of an area including a connecting member 22 connecting the tractor 10 and the trailer 20 and at least the front end of the trailer 20, for example, the area indicated by the two-dot chain line in Figure 1. The images captured by the imaging unit 12 can be used to detect the coupling angle, which indicates the left-right inclination of the trailer 20 relative to the tractor 10. The coupling angle is also referred to as a hitch angle, which will be described later.

[0017] The imaging unit 12 provided at the front end of the tractor 10 sequentially captures images of the area in front of the tractor 10 and generates captured images for recognizing the situation in front of the tractor 10. The imaging units 12 provided at the left and right side mirrors of the tractor 10 sequentially capture images of the area to the sides of the tractor 10 and generate captured images for recognizing the situation to the sides of the tractor 10.

[0018] By performing various image processing, including viewpoint change or synthesis, on the images obtained by the multiple imaging units 12 as described above, it may be possible to generate a peripheral image representing the situation around the tractor 10, such as an image with a wider field of view than an image obtained by only a single imaging unit 12, or a virtual overhead image of the tractor 10 viewed from above.

[0019] The number, layout, etc. of the imaging units 12 provided on the tractor 10 can be set in various ways.

[0020] A hitch 18, which is a towing device for towing a trailer 20, protrudes from, for example, a lower portion of the center portion of the rear bumper 16 of the tractor 10 in the vehicle width direction. The hitch 18 is fixed, for example, to the frame of the tractor 10. As an example, the hitch 18 has a hitch ball 19 that stands upright in the vertical direction (in the vehicle up-and-down direction) and has a spherical tip. A coupler provided at the tip of a connecting member 22 fixed to the trailer 20 covers the hitch ball 19. As a result, the tractor 10 and the trailer 20 are connected, and the trailer 20 can turn in the vehicle width direction relative to the tractor 10. In other words, the hitch ball 19 transmits forward / backward and left / right movement to the trailer 20 via the hitch 18, and also receives acceleration and deceleration power.

[0021] The trailer 20 may be, for example, a box-type trailer including at least one of a boarding space, a living space, a storage space, etc., as shown in Fig. 1, or may be a bed-type trailer for carrying cargo such as a container or a boat. The trailer 20 shown in Fig. 1 is, for example, equipped with a pair of wheels 24. The trailer 20 of the embodiment is a driven vehicle equipped with driven wheels that do not include driving wheels and steering wheels.

[0022] (Example of a traction assistance system configuration) The tractor 10 of the embodiment is equipped with, for example, a traction assist system 100. The traction assist system 100 assists the driving of the tractor 10 towing the trailer 20.

[0023] 3 is a diagram showing an example of the configuration of the traction assist system 100 provided in the tractor 10 according to the embodiment. As shown in FIG. 3, the traction assist system 100 includes a traction assist device 30, a monitor device 40, a steering system 51, an actuator 52, a torque sensor 53, a steering angle sensor 61, a shift sensor 62, a wheel speed sensor 63, and an imaging unit 12.

[0024] In traction assist system 100, traction assist device 30, monitor device 40, steering system 51, steering angle sensor 61, shift sensor 62, and wheel speed sensor 63 are electrically connected via an in-vehicle network 80, which is an electric communication line or the like. In-vehicle network 80 is configured as, for example, a CAN (Controller Area Network).

[0025] The traction assist device 30 is, for example, an electronic control unit (ECU) or the like, and is configured as a computer having a CPU (Central Processing Unit) 31, a ROM (Read Only Memory) 32, a RAM (Random Access Memory) 33, and an SSD (Solid State Drive) 34.

[0026] The CPU 31 can read out a program installed and stored in a nonvolatile storage device such as the ROM 32 and execute arithmetic processing in accordance with the program. The RAM 33 temporarily stores various data used in the calculations of the CPU 31. The SSD 34d is a rewritable nonvolatile storage unit that can store data even when the power to the traction assist device 30 is turned off.

[0027] The CPU 31, ROM 32, RAM 33, etc. may be integrated in the same package. The towing assistance device 30 may be configured to use another logic operation processor, such as a DSP (Digital Signal Processor), or a logic circuit, instead of the CPU 31. The SSD 34 may be replaced with an HDD (Hard Disk Drive), or the SSD 34 or HDD may be provided separately from the towing assistance device 30.

[0028] Traction assist device 30 can control steering system 51 and the like by sending control signals via in-vehicle network 80. In addition, traction assist device 30 can receive detection results, etc. from torque sensor 53, steering angle sensor 61, shift sensor 62, wheel speed sensor 63, etc. via in-vehicle network 80. CPU 31 included in traction assist device 30 can receive operation signals, etc. from operation input unit 42, etc. provided in monitor device 40, and can output control signals, etc. to display device 41, audio output device 43, etc. Images captured by multiple imaging units 12 are also input to CPU 31.

[0029] The monitor device 40 includes a display device 41, an operation input unit 42, and an audio output device 43, and is disposed in the center of the dashboard in the vehicle width direction (left and right direction).

[0030] The display device 41 is, for example, an LCD (Liquid Crystal Display), an OLED (Organic Electroluminescent Display), etc. The display device 41 can display an image captured by the imaging unit 12 under the control of the towing assistance device 30, for example, when the trailer 20 is pushed back and towed in reverse by the tractor 10 traveling in reverse.

[0031] Furthermore, the display device 41 is covered with an operation input unit 42 such as a transparent touch panel. The driver of the tractor 10 can view images displayed on the screen of the display device 41 via the operation input unit 42. Furthermore, the driver can execute various instructions to the traction assist device 30 by operating the operation input unit 42 with a finger or the like at a position corresponding to the image displayed on the screen of the display device 41.

[0032] As an example, the driver can instruct tow assist device 30 to start tow assist by operating operation input unit 42. At this time, the driver may be able to select, for example, a reverse parking assist mode or a forward parking assist mode.

[0033] The reverse parking assist mode is selected when parking the tractor 10 and trailer 20 while towing the trailer 20 in reverse with the tractor 10. The forward parking assist mode is selected when parking the tractor 10 and trailer 20 while towing the trailer 20 forward with the tractor 10. The towing assist device 30 performs towing assist according to the selected mode.

[0034] The audio output device 43 is, for example, a speaker.

[0035] The monitor device 40 may be used in conjunction with a navigation system, an audio system, etc., or may be provided separately from these systems.

[0036] The steering system 51 is, for example, an electric power steering system or a steer-by-wire (SBW) system, and includes an actuator 52 and a torque sensor 53.

[0037] The steering system 51 uses the actuator 52 to apply torque, i.e., assist torque, to a steering section such as a steering wheel to supplement the steering force, and also steers the wheels 14 using the actuator 52. In the tractor 10 of this embodiment, the front wheels 14F are assumed to be steered wheels. However, the actuator 52 may steer one wheel 14 or multiple wheels 14.

[0038] The steering system 51 is electrically controlled by the traction assist device 30 or the like, or operates the actuator 52 in accordance with the driver's operation of a steering unit such as a steering wheel. The torque sensor 53 detects the torque applied to the steering unit by, for example, the driver.

[0039] The steering angle sensor 61 is an angle sensor that detects the amount of steering of a steering unit such as a steering wheel. The amount of steering of the steering unit is the steering angle of the tractor 10. The steering angle sensor 61 is configured using, for example, a Hall element, and detects the rotation angle of a rotating part included in the steering unit. The traction assist device 30 acquires the amount of steering of the steering unit by the driver, the amount of steering of the wheels 14 during automatic steering, etc. from the steering angle sensor 61 and performs various controls.

[0040] The shift sensor 62 is a sensor that detects the position of a movable part of a gear change operation part, such as a shift lever. The shift sensor 62 can detect the position of a movable part such as a lever, arm, or button. The shift sensor 62 may include a displacement sensor or may be configured as a switch.

[0041] The wheel speed sensors 63 are sensors that detect the amount of rotation and the number of rotations per unit time of the wheels 14. The wheel speed sensors 63 are arranged on each wheel 14 and output the number of wheel speed pulses indicating the number of rotations detected at each wheel 14 as a sensor value. The wheel speed sensors 63 can be configured using, for example, Hall elements. The traction assist device 30 calculates the amount of movement of the tractor 10 based on the sensor values ​​acquired from the wheel speed sensors 63 and performs various controls.

[0042] The configurations, arrangements, and electrical connection forms of the various sensors and actuators described above are merely examples, and various settings are possible.

[0043] (Example of configuration of traction assist device) Next, an example of the functional configuration of the towing assistance device 30 according to the embodiment will be described with reference to Fig. 4. Fig. 4 is a block diagram showing an example of the functional configuration of the towing assistance device 30 according to the embodiment.

[0044] 4, towing assistance device 30 includes, as functional units, an acquisition unit 301, a detection unit 302, a calculation unit 303, an output unit 304, and a storage unit 305. These functional units of towing assistance device 30 are realized by CPU 31 described above expanding a program stored in ROM 32 or the like into RAM and executing the program.

[0045] The programs executed by the CPU 31 may be provided by being recorded in an installable or executable file format on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disk), or a USB (Universal Serial Bus), or may be provided or distributed via a network such as the Internet. Also, various programs may be provided by being pre-installed in a non-volatile storage medium such as a ROM.

[0046] However, the present invention is not limited to the above configuration, and may be configured such that at least some of the above functional units are realized by dedicated hardware circuits.

[0047] An example in which the driver selects a reverse parking assist mode or the like and the towing assist device 30 assists the tractor 10 towing the trailer 20 in reverse parking will be described below.

[0048] The acquisition unit 301 acquires the images captured by the above-mentioned plurality of image capturing units 12 as image data.

[0049] The detection unit 302 detects a parking area around the tractor 10 based on the captured image acquired by the acquisition unit 301. The parking area is detected by recognizing, for example, white lines, frame lines, wheel chocks, walls surrounding the parking area, and the like, that are marked in the parking area from the captured image.

[0050] To start reverse parking assistance, the driver parks the tractor 10, for example, near the entrance to the parking area. Therefore, the detection unit 302 can detect the parking area solely from the image captured by the image capturing unit 12 provided in the side mirror on the parking area side, out of the left and right side mirrors.

[0051] The calculation unit 303 calculates a target route for driving the tractor 10 to the parking area based on the positional relationship between the parking area detected by the detection unit 302 and the tractor 10.

[0052] As described above, when the driver parks the tractor 10 near the entrance to the parking area and instructs the start of reverse parking assistance, the calculation unit 303 generates a target path that includes a forward path that moves the tractor 10 forward from the reverse parking start position, a turning position that changes the tractor 10 from forward to reverse, and a reverse path that moves the tractor 10 backward from the turning position to the target parking position within the parking area.

[0053] The output unit 304 transmits a signal to the tractor 10 to control the tractor 10 so that the tractor 10 travels along the target route.

[0054] The storage unit 305 stores various parameters, programs, etc. required for the functions of the traction assist device 30.

[0055] (Example of operation of traction assist device) Next, an example of the operation of the traction assist device 30 of the embodiment will be described with reference to FIGS.

[0056] 5 to 9 are explanatory diagrams showing an example of the operation of the traction assist device 30 according to the embodiment to generate a forward route Ra among the target routes. In the example of Fig. 5 to 9, as described above, it is assumed that the reverse parking assistance is started from a position where the tractor 10 is parked alongside near the entrance to the parking area PR.

[0057] FIG. 5 shows an example of a default stopping position Ps and a default route Rs that are preset in the traction assist device 30.

[0058] As shown in Figure 5, the default stopping position Ps is set a distance Xd in front of the tractor 10 from the tractor position Pm, which is the center point of the pair of rear wheels 14R, which are the drive wheels of the tractor 10, i.e., the midpoint of the axle of the rear wheels 14R.

[0059] The default stopping position Ps is set assuming that it is a position on one of both sides of the parking area PR in the width direction, on the side that is forward of the tractor 10. That is, as in the example shown in Fig. 5, when the parking area PR is on the right side of the tractor 10, the default stopping position Ps corresponds to a position on the right side of the parking area PR when looking from the parking area PR side toward the entrance.

[0060] In this case, the parking area PR is assumed to extend in the depth direction perpendicular to the side of the tractor 10. In other words, the parking area PR is assumed to be positioned so that the depth direction is perpendicular to the center line of the tractor 10 in the fore-and-aft direction.

[0061] The default route Rs is set in advance based on the default stopping position Ps, and is a route for moving the tractor 10, which is at the start position of the reverse parking assistance, forward from the tractor position Pm to a predetermined forward position. The default route Rs is set, for example, so as to draw an S-shape from the tractor position Pm to the forward position, based on the default stopping position Ps, so that the tractor 10 can be parked properly in the parking area PR.

[0062] FIG. 6 shows an example of deviation amounts ΔXh and ΔXs of the parking area PR actually detected by the towing assistance device 30 with respect to the default stopping position Ps.

[0063] As shown in Figure 6, when the detection unit 302 detects the parking area PR after the start of reverse parking assistance, the calculation unit 303 of the towing assistance device 30 calculates the deviation amounts ΔXh and ΔXs from the default stopping position Ps, setting the position of the side of the parking area PR on the front side of the tractor 10 as the target stopping position Pa.

[0064] The deviation amount ΔXh from the default stop position Ps is the deviation amount of the target stop position Pa from the default stop position Ps in the forward direction of the tractor 10. In other words, as shown in the following equation (1), the deviation amount ΔXh is the value obtained by subtracting the above-mentioned distance Xd from the distance Xa from the tractor position Pm to the target stop position Pa.

[0065] ΔXh=Xa-Xd (1)

[0066] The deviation amount ΔXs from the default stopping position Ps is the deviation amount caused by the inclination of the target stopping position Pa with respect to the default stopping position Ps. In other words, the deviation amount ΔXs is the deviation amount from the default stopping position Ps in the forward direction of the tractor 10 at the position where an imaginary line extended from the side of the parking area PR set as the target stopping position Pa intersects with the center line of the tractor 10 in the fore-and-aft direction. Therefore, the deviation amount ΔXs can be expressed by the following equation (2).

[0067] ΔXs=Ya·tanθ···(2)

[0068] The parking angle θ is the angle formed by an imaginary line extending from the default stopping position Ps parallel to the left-right width of the tractor 10 and an imaginary line extending from the side of the parking area PR set as the target stopping position Pa. The distance Ya is the distance from the point where the imaginary line extending from the default stopping position Ps intersects with the imaginary line extending from the side of the parking area PR to the center line of the tractor 10 in the fore-and-aft direction.

[0069] The settings of the above-mentioned default stopping position Ps and default route Rs are stored, for example, in the memory unit 305 of the towing assistance device 30, and the calculation unit 303 reads these settings from the memory unit 305 and calculates the deviation amounts ΔXh and ΔXs based on the above equations (1) and (2).

[0070] FIG. 7 shows an example of a preparatory route Rp and a forward route Ra that are generated by the traction assist device 30 based on the deviation amounts ΔXh and ΔXs from the default stopping position Ps.

[0071] 7, the calculation unit 303 of the traction assist device 30 generates a forward route Ra that is shifted from the tractor position Pm to a position forward of the tractor 10 by these deviation amounts ΔXh and ΔXs. The calculation unit 303 also adds to the forward route Ra a preparatory route Rp that moves the tractor 10 forward from the tractor position Pm to the starting point Pc of the forward route Ra.

[0072] However, if the sum of the deviation amounts ΔXh and ΔXs is a negative value, the calculation unit 303 generates the forward route Ra without shifting the start point Pc or adding the preparatory route Rp. In other words, in this case, the default route Rs becomes the forward route Ra as is.

[0073] Therefore, the distance of the preparatory route Rp from the tractor position Pm to the starting point Pc of the forward route Ra can be expressed by the following equation (3) using the max function.

[0074] Distance of preliminary route Rp = max(0,ΔXh+ΔXs) (3)

[0075] The max function in the above formula (3) means that the deviation amount of the start point Pc of the forward route Ra is set to the larger of 0 or the sum of the deviation amounts (ΔXh + ΔXs). The deviation amount of the start point Pc of the forward route Ra based on formula (3) also corresponds to the distance of the preparatory route Rp.

[0076] 8 and 9 show examples in which the total value (ΔXh+ΔXs) of the deviation amounts from the default stopping position Ps is a negative value.

[0077] As shown in Fig. 8, if a command to start reverse parking assistance is issued when the tractor 10 has moved too far forward relative to the parking area PR, the target stopping position Pa will be located closer to the front of the tractor 10 than the default stopping position Ps, and the deviation amount ΔXh will be a negative value. Note that in the example of Fig. 8, the depth direction of the parking area PR extends perpendicular to the side of the tractor 10, and the parking angle θ is 0, so the deviation amount ΔXs due to the parking angle θ is also 0.

[0078] As shown in Fig. 9, another example of when the tractor 10 moves too far forward relative to the parking area PR is when the parking angle θ is tilted toward the front of the tractor 10. In this case, the deviation amount ΔXs is a negative value. In the example of Fig. 9, the default stopping position Ps based on the entrance to the parking area PR and the target stopping position Pa are the same, and the deviation amount ΔXh is zero.

[0079] 10 and 11 are explanatory diagrams showing an example of the operation of the traction assist device 30 in the reverse parking assistance according to the embodiment. Figures 10 and 11 show an example in which the traction assist device 30 controls the travel of the tractor 10 so that the tractor 10 follows a target route including the forward route Ra generated by the operations shown in Figures 5 to 7 above.

[0080] When starting the driving control of the tractor 10, the traction assist device 30 generates the entire target route that includes the forward route Ra described above and leads to the target parking position.

[0081] As shown in FIG. 10, the output unit 304 of the traction assist device 30 outputs a signal to the tractor 10 to control the traveling of the tractor 10, and causes the tractor 10 to travel along the forward route Ra included in the target route.

[0082] As shown in Figure 11, the output unit 304 continues to output a control signal for the tractor 10, causes the tractor 10 to reverse from a turning point Pb included in the target route, causes the tractor 10 to travel along a reverse route Rb included in the target route, and stops the tractor 10 at a position where the tractor position Pm coincides with the target parking position Pt.

[0083] As a result of the above, the tractor 10 and the trailer 20 are parked in the parking area PR, and the reverse parking assistance operation by the traction assistance device 30 is completed.

[0084] (Example of processing for traction assist device) Next, a processing example of the towing assistance device 30 according to the embodiment will be described with reference to Fig. 12. Fig. 12 is a flowchart showing an example of a procedure for generating a target route for back-in parking by the towing assistance device 30 according to the embodiment.

[0085] 12, the acquisition unit 301 of the traction assist device 30 acquires captured images from the multiple imaging units 12 provided on the tractor 10 (step S101). The detection unit 302 detects the parking area PR around the tractor 10 based on these captured images (step S102).

[0086] The calculation unit 303 reads out the setting of the default stopping position Ps from the storage unit 305, and calculates the amount of deviation ΔXh in the longitudinal direction of the tractor 10 from the target stopping position Pa identified from the detected parking area PR using the above formula (1) (step S103). The calculation unit 303 also calculates the amount of deviation ΔXs from the default stopping position Ps caused by the parking angle θ of the target stopping position Pa using the above formula (2) (step S104). Furthermore, the calculation unit 303 calculates the sum of these amounts of deviation ΔXh and ΔXs (step S105).

[0087] The calculation unit 303 determines whether the sum of the deviation amounts ΔXh and ΔXs is a negative value (step S106).

[0088] If the combined deviation amounts ΔXh and ΔXs are positive (step S106: No), the calculation unit 303 generates a preparatory route Rp having a distance equal to the combined value of the deviation amounts ΔXh and ΔXs (step S107).

[0089] If the sum of the deviation amounts ΔXh and ΔXs is a negative value (step S106: Yes), the calculation unit 303 determines whether the negative amount of the sum of the deviation amounts ΔXh and ΔXs is equal to or greater than a predetermined value (step S109).

[0090] If the negative amount of the deviations ΔXh and ΔXs is less than the predetermined value (step S109: No), the calculation unit 303 does not disallow the preparatory route Rp based on the sum of the deviations ΔXh and ΔXs in accordance with the max function of the above equation (3). In other words, the above process of step S107 is skipped.

[0091] If the negative amounts of the deviations ΔXh and ΔXs are equal to or greater than a predetermined value (step S109: Yes), it may be difficult or impossible to generate a target route that includes the forward route Ra and ultimately leads to the target parking position Pt. In this case, the calculation unit 303 ends the target route generation process with an error (step S110).

[0092] If the deviation amounts ΔXh, ΔXs are positive values ​​(step S106: No), or if the negative amount of the deviation amounts ΔXh, ΔXs is less than a predetermined value (step S109: No), the calculation unit 303 generates a target route including a forward route Ra with a preparatory route Rp added and a starting point shifted by the deviation amounts ΔXh, ΔXs, or a forward route Ra that maintains the position of the starting point of the default route Rs (step S108).

[0093] This completes the target route generation process by the traction assist device 30 of this embodiment.

[0094] (Overview) A towing assist device provides towing assistance to a tractor towing a trailer, etc. In reverse parking assistance for a tractor, a target route is generated that includes, for example, a forward route for moving the tractor forward, a turning position for turning the tractor, and a reverse route for moving the tractor backward. However, in order to appropriately generate a target route that includes multiple routes according to various positional relationships between the tractor and the parking area at the start position of the reverse parking assistance, complex calculations are required, which increases calculation costs, and generation of the target route itself can be difficult.

[0095] According to the towing assistance device 30 of this embodiment, the calculation unit 303 generates a target route including a forward route Ra and a reverse route Rb of the tractor 10 based on a preset default stopping position Ps and default route Rs. In this way, by generating the forward route Ra based on the preset default route Rs, route generation can be easily performed regardless of the positional relationship between the tractor 10 and the target stopping position Pa and the parking angle θ.

[0096] According to the embodiment of the towing assistance device 30, when the sum of the deviation amount ΔXh in the fore-and-aft direction of the tractor 10 and the deviation amount ΔXs in the fore-and-aft direction of the tractor 10 that occurs according to the parking angle θ when parking the tractor 10 in the parking area PR, which is the deviation amount between the target stopping position Pa determined based on the parking area PR and the default stopping position Ps, is a positive value, the calculation unit 303 generates a forward route Ra in which the position of the starting point of the default route Rs is shifted forward of the tractor 10 by the sum of the above-mentioned deviation amounts ΔXh and ΔXs.

[0097] This makes it possible to generate a forward path Ra according to the positional relationship between the tractor 10 and the target stopping position Pa and the parking angle θ. In addition, since the target path is generated taking into consideration the deviation ΔXs due to the parking angle θ, even if the parking angle θ is large, for example, a compact target path including turning can be generated, and stable path generation is also possible.

[0098] According to the towing assistance device 30 of this embodiment, when the sum of the above-mentioned deviation amounts ΔXh and ΔXs is a positive value, the calculation unit 303 shifts the position of the start point of the default route Rs and generates a forward route Ra to which a preparatory route Rp for moving the tractor 10 forward by the amount of the above-mentioned sum is added. In this way, by shifting the position of the start point Pc of the forward route Ra and then adding a preparatory route Rp for moving the tractor 10 forward to the position of the start point Pc, route generation can be easily performed.

[0099] According to the traction assist device 30 of this embodiment, when the sum of the deviation amounts ΔXh and ΔXs is a negative value less than a predetermined amount, the calculation unit 303 generates a forward route Ra in which the position of the start point of the default route Rs is maintained. In this way, under the predetermined conditions as described above, the default route Rs can be used as the forward route Ra as is, making it possible to easily generate a route.

[0100] (Variation) Next, a towing assist device according to a modification of the embodiment will be described with reference to Figures 13 to 15. The towing assist device according to the modification differs from the above-described embodiment in that, when the deviation amounts ΔXh and ΔXs between the default stop position Ps and the target stop position Pa are negative values, these values ​​are reflected in the target route generation.

[0101] 13 and 14 are explanatory diagrams showing an example of an operation of a traction assist device according to a modified embodiment to generate a forward path among the target paths. In the following description, the same reference numerals are used to designate the same components as those in the above-described embodiment, and the description thereof may be omitted.

[0102] In the example shown in FIG. 13, deviation amounts ΔXh and ΔXs, both of which are negative values, occur with respect to the preset default stopping position Ps.

[0103] 13, the target stopping position Pa, which is the side of the parking area PR in front of the tractor 10, is located closer to the front of the tractor 10 than the default stopping position Ps. In this case, the distance Xa from the tractor position Pm to the target stopping position Pa is the distance from the tractor position Pm to the side position at the entrance position in front of the tractor 10. Therefore, the deviation amount ΔXh, that is, the value of (Xa-Xd) is negative.

[0104] Furthermore, the parking area PR is inclined toward the front side of the tractor 10, and the amount of deviation ΔXs, that is, the value of Ya·tan θ, is also negative.

[0105] As shown in FIG. 14, in the towing assistance device of the modified example, the calculation unit 303 generates a forward route Ra by adding a preparatory route Rq based on the following equation (4), regardless of whether the sum of the deviation amounts ΔXh and ΔXs is positive or negative.

[0106] Distance of preliminary route Rq = ΔXh + ΔXs (4)

[0107] In other words, if the sum of the deviation amounts ΔXh and ΔXs is a positive value, the calculation unit 303 shifts the starting point Pc of the forward path Ra forward of the tractor 10 by that amount, and also adds a preliminary path Rq that moves the tractor 10 forward from the tractor position Pm to the starting point Pc of the forward path Ra.

[0108] On the other hand, if the sum of the deviation amounts ΔXh and ΔXs is a negative value, the calculation unit 303 adds a preliminary route Rq that moves the tractor 10 backward from the starting point Pc of the forward route Ra by the sum of the deviation amounts ΔXh and ΔXs without shifting the starting point Pc of the forward route Ra.

[0109] FIG. 15 is a flowchart showing an example of a procedure for generating a target route for back-in parking by a traction assist device according to a modified example of the embodiment.

[0110] As shown in FIG. 15, in the towing assist device of the modified example, the processing of steps S201 to S208 is performed in the same manner as the processing of steps S101 to S108 in FIG. 12 of the above-described embodiment.

[0111] On the other hand, if the sum of the deviation amounts ΔXh and ΔXs is a negative value, the calculation unit 303 generates a preparatory route Rq that moves the tractor 10 backward by the sum of the deviation amounts ΔXh and ΔXs. The calculation unit 303 also generates a target route that includes the preparatory route Rq (step S208).

[0112] This completes the process of generating a target route by the traction assist device of the modified example.

[0113] According to the towing assistance device of the modified example, when the sum of the deviation amounts ΔXh and ΔXs is a negative value, the calculation unit 303 generates a preparatory route Rq that moves the tractor 10 backward from the starting point of the default route Rs by the sum of the deviation amounts ΔXh and ΔXs. This allows for more flexible route generation.

[0114] In the above-described embodiment and modified example, the configuration is adapted to accommodate changes in the deviation amounts ΔXh, ΔXs of the target stopping position Pa depending on the position at which the tractor 10 is parked next to the parking area PR when reverse parking assistance is started. However, the parking area PR detected by the detection unit 302 of the towing assistance device 30 may be moved arbitrarily by the driver on the monitor device 40, for example, and the configurations of the above-described embodiment and modified example can also easily generate a route in accordance with such an operation.

[0115] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments or variations may be appropriately combined. [Explanation of symbols]

[0116] 10 Tractor 20 Trailer 30 Traction support device 100 Traction Assist System 301 Acquisition Department 302 Detection unit 303 Arithmetic section 304 Output section 305 Storage section

Claims

1. A towing assistance device that assists a towing vehicle that tows a towed vehicle in reverse parking, a detection unit that detects a parking area having an entrance on a side of the towing vehicle; a calculation unit that generates a target route including a forward route and a reverse route for the towing vehicle based on a preset default stopping position and a default route, The calculation unit calculating a deviation amount between the target stopping position determined based on the parking area and the default stopping position, the deviation amount being a first deviation amount in the front-to-rear direction of the towing vehicle and a second deviation amount in the front-to-rear direction of the towing vehicle that occurs in accordance with a parking angle when the towing vehicle is parked in the parking area; generating the forward path based on a sum of the first and second deviation amounts; Traction support device.

2. The calculation unit If the sum is a positive value, the position of the start point of the default route is shifted, and a preliminary route is added to move the towing vehicle forward by the sum, thereby generating the forward route. The traction assist device of claim 1 .

3. The calculation unit If the sum is a negative value less than a predetermined amount, the forward route is generated while maintaining the position of the starting point of the default route. The traction assist device of claim 1 .

4. The calculation unit If the sum is a negative value, a preliminary route is generated in which the towing vehicle is moved backward by the sum from the starting point of the default route. The traction assist device of claim 1 .

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