Work vehicles

Abstract

There are work vehicles equipped with a rear-view sensor at the rear of the vehicle body. When the rear-view sensor detects an obstacle approaching the vehicle at close range, it prioritizes driving suppression control over autonomous driving, thereby preventing the rear of the vehicle from contacting the obstacle. However, when work equipment that obstructs the detection range of the rear-view sensor is attached, the obstacle cannot be properly detected. Therefore, this invention provides a work vehicle that can be driven safely. [Solution] In a work vehicle equipped with a rear monitoring sensor 23 that detects obstacles behind the vehicle body 2 and a work machine W attached to the rear, in a check mode that checks whether the work machine W is within the detection range of the rear monitoring sensor 23, if it is detected that the work machine W is within the detection range of the rear monitoring sensor 23, the rearward detection of the rear monitoring sensor 23 during automatic driving is disabled and reverse movement is restricted.

Description

Technical Field

[0001] The present invention relates to a work vehicle such as a tractor, a construction machine, or a transport vehicle.

Background Art

[0002] There is a work vehicle that can avoid contact between the rear part of the vehicle body and an obstacle by providing a rear monitoring sensor behind the vehicle body and performing travel suppression control with priority over automatic driving when the rear monitoring sensor confirms the approach of an obstacle at a short distance from the vehicle body (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when a work implement that blocks the detection range of the rear monitoring sensor is mounted, an obstacle cannot be appropriately detected.

[0005] An object of the present invention is to provide a work vehicle that can travel safely in view of the above problems.

Means for Solving the Problems

[0006] The invention according to claim 1 is a work vehicle provided with a rear monitoring sensor 23 for detecting an obstacle behind a traveling vehicle body 2 and having a work implement W mounted on the rear part, and in a check mode for checking whether the work implement W has entered the detection range of the rear monitoring sensor 23, when it is detected that the work implement W has entered the detection range of the rear monitoring sensor 23, the detection behind the rear monitoring sensor 23 during automatic driving is invalidated, and the vehicle is restricted from reversing.

[0007] According to the invention described in claim 1, safe driving is possible by restricting automatic reverse movement when the rear monitoring sensor 23 is unable to detect properly.

[0008] The invention described in claim 2 is a work vehicle according to claim 1, having a work path generation unit that generates work paths RA and RB, and when it detects in check mode that the work machine W is within the detection range of the rear monitoring sensor 23, the work path generation unit generates a work path RB that is forward only and suppresses reverse movement.

[0009] According to the invention described in claim 2, even if the rearward detection of the rearward monitoring sensor 23 is disabled, safe automatic operation is possible.

[0010] The invention described in claim 3 is a work vehicle according to claim 1 or 2, which can be reversed by operating a remote control device 24, and when it detects that the work machine W is within the detection range of the rear monitoring sensor 23 in check mode, it reverses at a slower speed than when it is not detected.

[0011] According to the invention described in claim 3, when reversing using the remote control device 24, the vehicle can be reversed safely by reversing at a slower speed than usual. [Brief explanation of the drawing]

[0012] [Figure 1] This is a left side view of a tractor according to an embodiment of the present invention. [Figure 2] This is an explanatory diagram of the turning process of a tractor according to an embodiment of the present invention. [Modes for carrying out the invention]

[0013] A tractor 1, which is an embodiment of the work vehicle disclosed in this application, will be described in detail with reference to the attached drawings.

[0014] The forward and backward directions refer to the direction of travel when the tractor 1 is moving straight, with the front side of the direction of travel defined as "forward" and the rear side as "rear." The direction of travel of the tractor 1 is the direction from the driver's seat 8 (described later) toward the steering wheel 9 when moving straight.

[0015] The left-right direction is the direction perpendicular to the front-back direction. That is, with the operator of tractor 1 seated in the driver's seat 8 and facing forward, the left side is "left" and the right side is "right".

[0016] The vertical direction is the direction parallel to the vertical direction. The front-back, left-right, and up-down directions are orthogonal to each other. Note that these directions are defined for the sake of explanation, and the present invention is not limited by these directions. Also, in the following, tractor 1 may be referred to as "machine body".

[0017] Furthermore, this invention is not limited to the embodiments shown below.

[0018] <Overall Structure> As shown in Figure 1, tractor 1 is an agricultural tractor that performs work in fields while moving under its own power. In addition to performing predetermined tasks while a driver (operator) is on board and driving around the field, tractor 1 can also perform predetermined tasks while automatically driving around the field, controlled by the control device 21 described later.

[0019] The tractor 1 is equipped with a work implement W such as a tilling rotary or harrow at the rear of the vehicle body 2, which can be raised and lowered by a lifting device 12a, and also tows a work implement W such as a compost spreader by a drawbar 12b, as in this embodiment.

[0020] <Vehicle in operation 2> As shown in Figure 1, the vehicle body 2 comprises a vehicle frame 3, front wheels 4, rear wheels 5, a hood 6, an engine E, a control unit 7, and a transmission case 10.

[0021] The vehicle frame 3 and the transmission case 10 form the main frame of the vehicle body 2.

[0022] The front wheels 4 are a pair on the left and right, and mainly serve as wheels for steering (steering wheels). The rear wheels 5 are a pair on the left and right, and mainly serve as driving wheels (drive wheels).

[0023] The tractor 1 may be configured to be able to switch between two-wheel drive (2WD) in which the rear wheels 5 drive and four-wheel drive (4WD) in which both the front wheels 4 and the rear wheels 5 drive. In the case of four-wheel drive (4WD), the drive wheels are both the front wheels 4 and the rear wheels 5. Incidentally, the traveling vehicle body 2 may be provided with a crawler device instead of the wheels (front wheels 4 and rear wheels 5). In this case, the traveling crawler is the drive wheel.

[0024] The bonnet 6 is provided at the front part of the traveling vehicle body 2 so as to be openable and closable. The bonnet 6 can rotate (open and close) in the vertical direction with the rear part as the rotation center. The bonnet 6 covers the engine E mounted on the vehicle body frame 3 in the closed state.

[0025] The engine E is the drive source of the tractor 1 and is a heat engine such as a diesel engine or a gasoline engine.

[0026] The operation part 7 is provided on the upper part of the traveling vehicle body 2 and includes an operator's seat 8, a steering wheel 9, etc. The operation part 7 is covered by a cabin 7a provided on the upper part of the traveling vehicle body 2.

[0027] The operator's seat 8 is the seat for the operator. The steering wheel 9 is operated by the operator when steering the front wheels 4 which are the steering wheels. Incidentally, the operation part 7 includes a meter panel 11 (display part) for displaying various information in front of the steering wheel 9.

[0028] Also, the operation part 7 includes various operation levers such as a forward and reverse lever, an accelerator lever, a main transmission lever, a sub-transmission lever, etc., and various operation pedals such as a clutch pedal 13, a brake pedal 14, an accelerator pedal 15, etc.

[0029] The transmission case 10 houses the transmission (speed change mechanism). The transmission reduces the power (rotational power) transmitted from the engine E as needed and transmits it to the drive wheels, which are the front and rear wheels 4 and 5, and the PTO shaft 16.

[0030] A drawbar 12b is provided at the rear of the vehicle body 2, to which a work implement W, such as a compost spreader used for work in the field, is attached and towed. A PTO shaft 16, which transmits power to drive the work implement W, protrudes rearward from the transmission case 10. The PTO shaft 16 transmits rotational power, which has been appropriately reduced by the transmission, to the work implement W mounted at least at the rear of the vehicle body 2.

[0031] Furthermore, a lifting device 12 is provided at the rear of the vehicle body 2 for raising and lowering implements W such as tilling rotary tillers and harrows. The lifting device 12 moves the implements W to a non-working position by raising them. The non-working position is the position in which the implements W are raised, for example, when the vehicle body 2 is moving backward or turning. The lifting device 12 also moves the implements W to a ground-level working position by lowering them.

[0032] The lifting device 12 includes a hydraulic lifting cylinder 121, a lift arm 122, and hitches (left and right lift rods, left and right lower links, top link, etc.) not shown.

[0033] Furthermore, a rolling cylinder is provided on one of the left and right lift rods, and the left-right tilt of the work machine W is adjusted by extending or retracting one of the left and right lift rods. In other words, the control device 21 detects the left-right tilt of the machine body using a left-right tilt sensor provided on the machine body and operates the rolling cylinder to control the work machine W so that it becomes horizontal, or the tilt of the work machine W can be adjusted by manually operating the rolling cylinder.

[0034] When hydraulic fluid is supplied to the lifting cylinder 121, the lift arm 122 rotates around the pivot point axis AX to raise the work implement W, and when the hydraulic fluid is discharged from the lifting cylinder 121, it rotates around axis AX to lower the work implement W.

[0035] Furthermore, a lift arm sensor is provided at the base of the lift arm 122 (near axis AX) as a lifting device sensor to detect the rotation angle of the lift arm 122.

[0036] The height of the work machine W is calculated based on the detection results of the lift arm sensor and the work machine ground height sensor attached to the work machine W. The control device 21 operates the lifting cylinder 121 based on the detected value of the work machine ground height sensor to control the work machine W to a predetermined ground height, or the height of the work machine W can be adjusted by manually operating the lifting cylinder 121.

[0037] Here, we will explain the autonomous driving control system of tractor 1.

[0038] The autonomous driving control system consists of a control device 21 that includes a GNSS 20 mounted on the tractor 1, a map database, a calendar year work database and other various databases, a wireless communication device 22, a rear camera 23 as a rearward monitoring sensor installed at the rear end of the roof of the cabin 7a, and a remote control terminal 24 as a remote control device such as a tablet or smartphone equipped with a wireless communication device.

[0039] The control device 21 calculates the work route RA or work route RB that the autonomous tractor 1 will perform in a round-trip process on the user-owned field F registered in the map database, and stores the work route RA or work route RB in the map database.

[0040] The control device 21 determines whether the rear camera 23 functions as a rearward monitoring sensor and calculates either the work path RA or the work path RB.

[0041] In other words, when a relatively small implement W such as a tilling rotary or harrow is attached to the rear of the vehicle body 2, the rear camera 23 can photograph the area behind the implement W and functions as a rear monitoring sensor. Therefore, when the control device 21 determines that the rear camera 23 can photograph the area behind the implement W, it calculates the work path RA in the field F that allows for reverse movement.

[0042] As shown in Figure 2(A), in the work path RA which allows reverse movement in field F, for example, when turning in field F, the vehicle turns at A at the end of the forward path R1, reverses B during the turn, resumes turning C, makes a tight turn S1, and proceeds to the return path R2.

[0043] In the diagram, A' represents the turning radius of turn A, C' represents the turning radius of turn C, and S1 represents the actual turning radius for tight turns.

[0044] When the vehicle is moving in reverse, the control device 21 automatically stops if the rear camera 23, which acts as a rear monitoring sensor, detects a person or obstacle, thereby ensuring safety. When the vehicle automatically stops, it also issues an audible warning or other notification indicating an obstacle behind the vehicle and displays the rear view on the display unit of the meter panel 11.

[0045] When a large implement W, such as a compost spreader, is attached to the rear of the vehicle body 2 and towed, the rear camera 23 cannot photograph the area behind the implement W and therefore does not function as a rear monitoring sensor. When the control device 21 determines that the rear camera 23 cannot photograph the area behind the implement W, it issues an audible warning or other notification stating that it will suppress reverse movement because the implement W cannot be detected behind the rear camera 23, and calculates the work path RB in field F where reverse movement is suppressed (prohibited).

[0046] As shown in Figure 2(B), in the work path RB where reverse movement is suppressed (prohibited) in field F, for example, when turning in field F, the vehicle turns a short distance O in the opposite direction of the turn at the end of the forward path R1, then makes a normal turn P, turns a short distance Q again in the opposite direction of the turn, and then makes a wide turn to proceed to the return path R2.

[0047] In the diagram, O' represents the turning radius of turning O, Q' represents the turning radius of turning Q, and P' represents the turning radius of turning P.

[0048] In short, before starting work, the control device 21 checks whether the work machine W is within the detection range of the rear camera 23, which acts as a rear monitoring sensor. If the control device 21 detects that the work machine W is within the detection range of the rear camera 23 (i.e., determines that it cannot detect the area behind the work machine W), it disables the rearward detection of the rear camera 23 during autonomous driving (automatic operation) and restricts reverse movement.

[0049] Therefore, by restricting automatic reverse movement when the rear camera 23, which acts as a rearward monitoring sensor, is unable to detect properly, safe driving can be achieved.

[0050] Furthermore, the control device 21 has a work path generation unit that generates work path RA or work path RB. In check mode, if it detects that the work machine W is within the detection range of the rear camera 23 (i.e., if it determines that the area behind the work machine W cannot be detected), the work path generation unit generates a work path RB that only allows forward movement and suppresses (prohibits) reverse movement.

[0051] Therefore, it can safely drive autonomously (autonomously) even without rearward detection.

[0052] Furthermore, tractor 1 will autonomously drive (automatically operate) along work route RA or work route RB in field F, receiving signals from positioning satellite S via GNSS20 and calculating its position information using the satellite positioning system, while performing the work automatically.

[0053] The remote control terminal 24 includes a control unit consisting of a hard disk, ROM, RAM, CPU, etc., a display unit (monitor) 24a consisting of a touch panel, and an operation unit 24b having various buttons such as an automatic operation switch and a manual operation switch. This allows the operator to set and command the tractor 1 to perform various tasks in field F.

[0054] For example, when the manual operation switch is pressed, various operation buttons appear on the display unit 24a, and when the reverse button is tapped, the tractor 1 can be moved in reverse remotely.

[0055] In other words, when the control device 21 is restricting reverse movement as described above, if reverse movement is necessary, the supervisor monitoring the tractor 1 can remotely reverse the tractor 1 by pressing the manual operation switch on the remote control terminal 24 while checking the surrounding area, including the rear, at the rear position of the tractor 1, and tapping the reverse button on the display unit 24a.

[0056] The control device 21 allows the tractor 1 to move in reverse by the remote control terminal 24.

[0057] At that time, the control device 21 cuts off the drive to the work machine W and reverses at a slower speed than the reverse speed when reverse movement is not restricted (reverse speed is restricted).

[0058] Furthermore, as described above, when the control device 21 detects that the implement W is within the detection range of the rear camera 23 (determining that it cannot detect the area behind the implement W) and disables the rearward detection of the rear camera 23 to restrict reverse movement (when the control device 21 restricts reverse movement), autonomous driving (automatic operation) cannot be started unless the supervisor taps the automatic operation switch on the remote control terminal 24 from outside (rear side) of the tractor 1 to issue a command.

[0059] Finally, in the above embodiment, an example was shown in which the control device 21 of the tractor 1 calculates and stores the work paths RA and RB. However, the remote control terminal 24 may receive data from the tractor 1 indicating whether or not the implement W is within the detection range of the rear camera 23, calculate the work path RA or work path RB for the tractor 1 to perform round-trip work in the field F owned by the user and registered in the map database, store the work path RA or work path RB in the map database, and transmit the data containing the work path RA or work path RB to the control device 21 of the tractor 1 for the control device 21 to store. [Explanation of symbols]

[0060] 2. Running vehicle 23. Rear monitoring sensor (rear camera) 24 Remote control device (remote control terminal) RA, RB work route W work machine

Claims

1. A work vehicle equipped with a rearward monitoring sensor (23) on the vehicle body (2) for detecting obstacles behind it, and with a work implement (W) mounted on the rear, characterized in that, in a check mode that confirms whether the work implement (W) is within the detection range of the rearward monitoring sensor (23), if the work implement (W) is within the detection range of the rearward monitoring sensor (23), the rearward detection of the rearward monitoring sensor (23) during automatic driving is disabled and reverse movement is restricted.

2. The work vehicle according to claim 1, having a work path generation unit that generates work paths (RA, RB), and in check mode, when it detects that the work machine (W) is within the detection range of the rear monitoring sensor (23), the work path generation unit generates a work path (RB) that is forward only and suppresses reverse movement.

3. The work vehicle according to claim 1 or 2, characterized in that it can be reversed by operating a remote control device (24), and when it detects that the work equipment (W) is within the detection range of the rear monitoring sensor (23) in check mode, it reverses at a slower speed than when it is not detected.

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