JP7120878B2 - Work equipment lifting control device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a work implement lifting control device provided in a work vehicle capable of lifting and lowering a work implement.

Patent Literature 1 discloses a rice transplanter configured such that the seedling planting portion does not come into contact with the field even when the machine travels near the entrance of a sloping field. This rice transplanter includes a traveling vehicle, a seedling planting device, a lift cylinder, an inclination sensor, and a control device. The seedling planting device is mounted so as to be able to move up and down with respect to the traveling vehicle. A lift cylinder raises/lowers a seedling planting apparatus by operating a piston. The tilt sensor detects the tilt angle in the longitudinal direction of the running vehicle. When the tilt sensor detects an angle equal to or greater than a predetermined value, the control device supplies pressurized oil to the lift cylinder to operate the piston, thereby raising the height of the seedling planting device.

JP 2012-130264 A

However, in Patent Document 1, when the above predetermined value is set small so as to enable accurate detection even when the gradient of the slope at the entrance to the field is small, the tilt angle of the traveling vehicle becomes equal to or greater than the predetermined value due to unevenness of the field. Therefore, the slope cannot be detected accurately. On the other hand, if the predetermined value is increased to prevent this erroneous detection, there is a possibility that a slope with a small gradient cannot be detected. Moreover, the difficulty in accurately detecting the slope is not limited to rice transplanters, but is a problem common to all work vehicles to which work implements can be attached.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its main object is to provide a working machine lifting and lowering apparatus for a working vehicle to which a working machine can be attached, in which the slope of the entrance/exit of a field is accurately detected to raise or lower the working machine. The object is to provide a control device.

Means and Effects for Solving Problems

The problems to be solved by the present invention are as described above. Next, the means for solving the problems and the effects thereof will be described.

According to a first aspect of the present invention, there is provided a working machine lifting control device having the following configuration. The work machine elevation control device includes an angle sensor, a position detection section, an angle determination section, a position determination section, a position calculation section, and an elevation control section. The angle sensor detects the pitch angle of the work vehicle, with the rotation direction in which the front portion of the work vehicle moves upward as the positive direction. The position detection unit detects the position of the work vehicle using a satellite positioning system. The angle determination unit determines whether the pitch angle detected by the angle sensor is greater than a first predetermined angle. When the angle determination unit determines that the pitch angle is greater than the first predetermined angle, the position determination unit connects the outside of the farm field at a position higher than the field from the current position of the working vehicle to the farm field. Determine whether the distance to the slope is less than or equal to the threshold . The position calculation unit determines a lift start position for lifting the work implement when the position determination unit determines that the distance is equal to or less than a threshold. The elevation control unit raises the work implement to a retracted position when the position of the work vehicle reaches the lift start position while heading from the farm field to the outside of the farm field .

As a result, whether or not to raise the work implement to the retracted position is determined based on not only the pitch angle of the work vehicle but also the position of the work vehicle. does not rise to the retracted position. Therefore, the work implement can be raised to the retracted position at the timing when the work vehicle is reliably moving up the slope to the outside of the field.

According to a second aspect of the present invention, there is provided a working machine lifting control device having the following configuration. That is, the work implement lifting control device includes an angle sensor, a position detection section, an angle determination section, a position determination section, and a position calculation section. The angle sensor detects the pitch angle of the work vehicle on which the work implement can be mounted. The position detection unit detects the position of the work vehicle using a satellite positioning system. The angle determination unit determines whether or not the pitch angle detected by the angle sensor is greater than a second predetermined angle. The position determination unit determines whether the current position of the work vehicle is at the position of the slope that connects the outside of the field, which is higher than the field, and the field. The position calculation unit determines that the pitch angle is greater than the second predetermined angle when heading toward the farm field from outside the farm field, and the position of the work vehicle is at the position of the slope. When the position determination unit determines that there is, a lowering start position for lowering the work implement is determined.

It is preferable that the work implement lift control device further includes a lift control section that starts lowering the work implement when the work vehicle reaches the lowering start position.

BRIEF DESCRIPTION OF THE DRAWINGS The side view which shows the whole structure of the tractor provided with the working-equipment raising/lowering control apparatus which concerns on one Embodiment of this invention. The top view of a tractor. FIG. 2 is a block diagram showing the electrical configuration of the tractor; The figure which shows the positional relationship of an agricultural field, a slope, and a road. 5 is a flow chart showing work implement lifting control performed when going from a field to a road. FIG. 5 is a diagram showing how the work implement rises before reaching the slope by performing work implement rise control; 4 is a flowchart showing work implement lowering control performed when heading from a road to a field; The figure which shows a mode that a working machine descend|falls to the edge part of an agricultural field by performing working machine lowering control. 4 is a flowchart showing a process for raising and lowering a working machine outside an agricultural field;

Next, an autonomous driving system that is an embodiment of the present invention will be described. An autonomous traveling system autonomously travels one or a plurality of work vehicles in a field (traveling area) to perform all or part of work. In this embodiment, a tractor is used as a working vehicle. machine is also included. In this specification, the term "autonomous traveling" means that at least steering is autonomously performed along a predetermined route by controlling a configuration related to traveling provided in the tractor by a control unit (ECU) provided in the tractor. means. Moreover, in addition to steering, the structure may be such that the vehicle speed or the work by the working machine is autonomously performed. Autonomous driving includes the case where the tractor is manned and the case where the tractor is not manned.

Next, the autonomous driving system 100 will be specifically described with reference to FIGS. 1 to 3. FIG. FIG. 1 is a side view showing the overall configuration of the tractor 1. FIG. FIG. 2 is a plan view of the tractor 1. FIG. FIG. 3 is a block diagram showing the main configuration of the control system of the autonomous driving system 100. As shown in FIG.

The tractor 1 shown in FIG. 1 is used in the autonomous driving system 100 and operated by performing wireless communication with the wireless communication terminal 46 . A tractor 1 includes a traveling body (body portion) 2 capable of autonomously traveling in a field. A working machine 3 for agricultural work, for example, is detachably attached to the rear part of the traveling body 2 .

Examples of the work machine 3 include various work machines such as cultivators, plows, fertilizers, lawn mowers, and seeders. Further, the traveling machine body 2 is configured such that the height and posture of the work machine 3 mounted thereon can be changed.

The configuration of the tractor 1 will be described in more detail with reference to FIGS. 1 and 2. FIG. As shown in FIG. 1, the traveling body 2 of the tractor 1 has a front portion supported by a pair of left and right front wheels (wheels) 7, and a rear portion supported by a pair of left and right rear wheels 8, 8. there is

A bonnet 9 is arranged on the front part of the traveling body 2 . An engine 10 which is a driving source of the tractor 1 and a fuel tank (not shown) are accommodated in the bonnet 9 . The engine 10 can be configured by, for example, a diesel engine, but is not limited to this, and may be configured by, for example, a gasoline engine. Also, an electric motor may be used as the drive source in addition to or instead of the engine.

A cabin 11 for a user to board is arranged behind the bonnet 9 . Inside the cabin 11, a steering handle (steering tool) 12 for the user to steer, a seat 13 on which the user can sit, and various operation tools for performing various operations are mainly provided. ing. However, the work vehicle such as the tractor 1 may or may not have the cabin 11 .

2, a monitor device 14, a throttle lever 15, a main gear lever 27, a plurality of hydraulic operating levers 16, a PTO switch 17, a PTO gear lever 18, an auxiliary gear lever 19, and a forward/reverse switching lever 25. , the parking brake 26, the working machine lift switch 28, and the like. These operating devices are arranged near the seat 13 or near the steering handle 12 .

The monitor device 14 is configured to be able to display various information about the tractor 1 . The throttle lever 15 is an operating tool for setting the rotation speed of the engine 10 . The main shift lever 27 is an operation tool for changing the running speed of the tractor 1 steplessly. The hydraulic operating lever 16 is an operating tool for switching a hydraulic external extraction valve (not shown). The PTO switch 17 is an operation tool for switching transmission/interruption of power to a PTO shaft (not shown) projecting from the rear end of the transmission 22 (power take-off shaft). That is, when the PTO switch 17 is in the ON state, power is transmitted to the PTO shaft, the PTO shaft rotates, and the working machine 3 is driven. As a result, the PTO shaft does not rotate, and the working machine 3 is stopped. The PTO speed change lever 18 is used to change the power input to the working machine 3, and more specifically, it is an operation tool for changing the rotation speed of the PTO shaft. The sub-transmission lever 19 is an operation tool for switching the gear ratio of the traveling sub-transmission gear mechanism in the transmission 22 . The forward/reverse switching lever 25 is configured to be switchable between a forward position, a neutral position, and a reverse position. When the forward/reverse switching lever 25 is in the forward position, the power of the engine 10 is transmitted to the rear wheels 8 so that the tractor 1 moves forward. When the forward/reverse switching lever 25 is in the neutral position, the tractor 1 does not move forward or backward. When the forward/reverse switching lever 25 is positioned at the reverse position, the power of the engine 10 is transmitted to the rear wheels 8 so that the tractor 1 moves backward. A parking brake (braking operation tool) 26 is an operation tool that is manually operated by a user to generate a braking force, and is used, for example, when stopping the tractor 1 for a while. The working machine lifting switch 28 is an operation tool for raising and lowering the height of the working machine 3 mounted on the traveling body 2 within a predetermined range.

As shown in FIG. 1 , a chassis 20 of the tractor 1 is provided below the traveling body 2 . The chassis 20 includes a body frame 21, a transmission 22, a front axle 23, a rear axle 24, and the like.

The body frame 21 is a supporting member in the front part of the tractor 1, and supports the engine 10 directly or via a vibration isolating member or the like. The transmission 22 changes the power from the engine 10 and transmits it to the front axle 23 and the rear axle 24 . The front axle 23 is configured to transmit power input from the transmission 22 to the front wheels 7 . The rear axle 24 is configured to transmit power input from the transmission 22 to the rear wheels 8 .

As shown in FIG. 3 , the tractor 1 has a control section 4 . The control unit 4 is configured as a known computer, and includes an arithmetic device such as a CPU, a storage device such as a non-volatile memory, an input/output unit, and the like (not shown). Various programs and data relating to control of the tractor 1 are stored in the storage device. The arithmetic device can read various programs from the storage device and execute them. By cooperation of the above hardware and software, the control unit 4 can be operated as the travel control unit 4a, the elevation control unit 4b, the work control unit 4c, the angle determination unit 4d, the position determination unit 4e, and the position calculation unit 4f. can. Note that the control unit 4 can also perform other controls (for example, analysis of captured images, etc.). Also, the control unit 4 may be composed of one computer, or may be composed of a plurality of computers.

The travel control unit 4 a performs vehicle speed control for controlling the vehicle speed of the tractor 1 and steering control for steering the tractor 1 . When performing vehicle speed control, the control unit 4 controls at least one of the rotation speed of the engine 10 and the gear ratio of the transmission 22 .

Specifically, the engine 10 is provided with a governor device 41 having an unillustrated actuator that changes the rotational speed of the engine 10 . The travel control unit 4 a can control the rotational speed of the engine 10 by controlling the governor device 41 . The engine 10 is also provided with a fuel injection device 45 that adjusts the injection timing and injection amount of fuel to be injected (supplied) into the combustion chamber of the engine 10 . By controlling the fuel injection device 45, the travel control unit 4a can stop the supply of fuel to the engine 10 and stop the driving of the engine 10, for example.

The transmission 22 is also provided with a transmission 42 that is, for example, a movable swash plate type hydraulic continuously variable transmission. The travel control unit 4a changes the gear ratio of the transmission 22 by changing the angle of the swash plate of the transmission 42 using an actuator (not shown). By performing the above processing, the tractor 1 is changed to the target vehicle speed.

The travel control unit 4a controls the rotation angle of the steering handle 12 when performing steering control. Specifically, a steering actuator 43 is provided at an intermediate portion of the rotating shaft (steering shaft) of the steering handle 12 . With this configuration, when the tractor 1 travels along a predetermined route, the control unit 4 calculates an appropriate rotation angle of the steering handle 12 so that the tractor 1 travels along the route. The steering actuator 43 is driven so as to achieve the rotation angle, and the rotation angle of the steering handle 12 is controlled.

The elevation control unit 4b controls elevation of the working machine 3. As shown in FIG. Specifically, the tractor 1 includes an elevating actuator 44 such as a hydraulic cylinder in the vicinity of the three-point link mechanism that connects the work implement 3 to the traveling body 2 . The elevation control unit 4b can drive the elevation actuator 44 to raise or lower the work implement 3. As shown in FIG. Thereby, the height of the working machine 3 can be changed between the working position and the retracted position. The working position is below the retracted position and is a position for performing work with the working machine 3 . Since it is sometimes preferable to perform work using the working machine 3 at a certain height with respect to the field, the working position includes not only the lowest position but also a slightly higher position. In addition, the retracted position includes not only the highest position but also a slightly lower position. The elevation control unit 4b raises and lowers the working machine 3 on or near the entrance/exit slope of the field based on the determination results of the angle determination unit 4d and the position determination unit 4e (details will be described later).

The work control unit 4c switches between driving and stopping the work implement 3 by controlling the PTO switch 17 based on whether the work execution condition is satisfied. Further, the work control unit 4c rotates the PTO shaft at a rotational speed determined based on predetermined conditions by controlling the PTO transmission mechanism and the like.

The tractor 1 equipped with the control unit 4 as described above controls each part of the tractor 1 (the traveling body 2, the working machine 3, etc.) by the control unit 4 even if the user does not enter the cabin 11 and perform various operations. Then, autonomous work can be performed while autonomously traveling in the field.

Next, a configuration for acquiring information necessary for autonomous travel will be described. Specifically, the tractor 1 of the present embodiment, as shown in FIG. A camera 57, a vehicle speed sensor 53, a steering angle sensor 52, and the like are provided.

The wireless communication antenna 48 receives signals from the wireless communication terminal 46 operated by the user and transmits signals to the wireless communication terminal 46 . As shown in FIG. 1 , the wireless communication antenna 48 is attached to the top surface of the roof 5 of the cabin 11 of the tractor 1 . A signal from the wireless communication terminal 46 received by the wireless communication antenna 48 is input to the control unit 4 after signal processing by the wireless communication unit 40 shown in FIG. A signal to be transmitted from the control unit 4 or the like to the wireless communication terminal 46 is processed by the wireless communication unit 40 , transmitted from the wireless communication antenna 48 and received by the wireless communication terminal 46 .

The inertial measurement unit (angle sensor) 61 is a sensor unit capable of identifying the attitude, acceleration, etc. of the traveling body 2 of the tractor 1 . The inertial measurement unit 61 includes three gyro sensors (angular velocity sensors) and three acceleration sensors. As a result, the inertial measurement unit 61 can specify the angular velocity (roll angular velocity, pitch angular velocity, and yaw angular velocity) of the attitude change of the traveling body 2 of the tractor 1, and the acceleration in the longitudinal direction, the lateral direction, and the vertical direction. It's becoming Also, by integrating the angular velocity, the posture (roll angle, pitch angle, yaw angle) of the tractor 1 can be specified. In this embodiment, the direction in which the front portion of the tractor 1 rotates to be higher than the rear portion is defined as a positive pitch angle, and the opposite direction is defined as a negative pitch angle.

The positioning antenna 6 receives signals from positioning satellites that form a positioning system such as the Global Positioning System (GNSS). As shown in FIG. 1 , the positioning antenna 6 is attached to the top surface of the roof 5 of the cabin 11 of the tractor 1 . A positioning signal received by the positioning antenna 6 is input to the position detection section 62 shown in FIG. The position detection unit 62 calculates and detects the position of the traveling body 2 (strictly speaking, the positioning antenna 6) of the tractor 1 as latitude/longitude information, for example. The position detected by the position detection unit 62 is input to the control unit 4 and used for autonomous travel.

In this embodiment, a high-precision satellite positioning system using the GNSS-RTK method is used. good too. For example, relative positioning (DGPS) or geostationary satellite augmentation system (SBAS) could be used.

The distance detection sensor 63 irradiates a transmission wave (electromagnetic wave) forward and receives a reflected wave (electromagnetic wave) of the transmission wave reflected by an object. The distance detection sensor 63 calculates the distance to the object based on the time from transmission of the transmission wave to reception of the reflected wave. Note that the analysis of the reflected wave may be performed by another computing device (for example, the control unit 4) arranged at a position away from the distance detection sensor 63. FIG. Further, in the present embodiment, the distance to the object is detected by transmitting/receiving electromagnetic waves, but the distance to the object may be detected by transmitting/receiving ultrasonic waves. When the control unit 4 identifies the presence of an obstacle based on the detection result of the distance detection sensor 63, the traveling control unit 4a stops the tractor 1 or changes the direction of travel to avoid the obstacle. Prevent contact. Note that the detection result of the distance detection sensor 63 is also used for work implement lowering control, which will be described later.

The front camera 56 is for photographing the front of the tractor 1 . The rear camera 57 is for photographing the rear of the tractor 1 . A front camera 56 and a rear camera 57 are mounted on the roof 5 of the tractor 1 . The moving image data captured by the front camera 56 and the rear camera 57 is transmitted from the wireless communication antenna 48 to the wireless communication terminal 46 by the wireless communication unit 40 . The wireless communication terminal 46 that has received the video data displays the content on the display.

The vehicle speed sensor 53 is for detecting the vehicle speed of the tractor 1, and is provided on the axle between the front wheels 7, 7, for example. Data of the detection result obtained by the vehicle speed sensor 53 is output to the control unit 4 . The vehicle speed of the tractor 1 may be calculated based on the travel time of the tractor 1 over a predetermined distance based on the positioning antenna 6 instead of being detected by the vehicle speed sensor 53 . The steering angle sensor 52 is a sensor that detects the steering angles of the front wheels 7,7. In this embodiment, the steering angle sensor 52 is provided on a kingpin (not shown) provided on the front wheels 7 , 7 . Data of the detection result obtained by the steering angle sensor 52 is output to the control section 4 . Note that the steering angle sensor 52 may be provided on the steering shaft.

The wireless communication terminal 46 is a tablet terminal, a smart phone, a notebook PC, or the like. The wireless communication terminal 46 is used, for example, by the user to make settings related to autonomous travel of the tractor 1 . Also, the wireless communication terminal 46 is used by the user to check the situation and to transmit instructions to the tractor 1 while the tractor 1 is autonomously traveling.

As shown in FIG. 4, in the vicinity of the field where the tractor 1 works, a road is provided for the tractor 1 to travel to the field. Also, the field is created at a lower position than the outside of the field such as roads. Therefore, fields and roads are connected by slopes. Therefore, this slope is slanted so that the height increases as it approaches the road (outside the field) from the field.

The wireless communication terminal 46 stores the positions and shapes of the above-described fields, slopes, and roads. The positions and shapes of the field, the slope, and the outside of the field are created based on the transition of the position of the positioning antenna 6 when the tractor 1 is actually driven. The positions and shapes of fields, slopes, and roads may be created by the user specifying ranges on a map displayed on the wireless communication terminal 46, for example, without actually running the tractor 1. . Based on the information stored in the wireless communication terminal 46 and the position detected by the position detection unit 62, it is possible to specify whether the tractor 1 is positioned on a field, on a slope, or on a road.

Further, the wireless communication terminal 46 creates and stores a route for autonomously traveling the tractor 1 in the field. The route includes, for example, a straight route along which the tractor 1 travels straight within the working area of the field, and a turning route that connects the straight routes.

Next, with reference to FIGS. 5 and 6, control for automatically raising the work implement 3 when going from the field to the road (hereinafter referred to as work implement lift control) will be described. This control is performed by the working machine lifting control device 80 . The work implement elevation control device 80 of the present embodiment includes an inertia measurement unit 61, a position detection section 62, a distance detection sensor 63, a work control section 4c, an angle determination section 4d, a position determination section 4e, a position calculation 4f.

First, the control unit 4 determines whether or not the work implement lift control is effective (S101). By performing a predetermined operation on the monitor device 14 or the wireless communication terminal 46, the user can switch between enabling and disabling the work implement ascending control. The control unit 4 makes the determination in step S101 based on the user's settings.

When the work implement rise control is valid, the control section 4 (angle determining section 4d) determines whether or not the pitch angle detected by the inertial measurement unit 61 is greater than the first predetermined angle (S102). Here, when the tractor 1 leaves the field and heads for the road, the tractor 1 goes up the slope, so the front part of the tractor 1 is higher than the rear part, and the pitch angle (positive value) increases. The pitch angle gradually increases after the front wheels 7 reach the slope, and reaches its maximum value when the rear wheels 8 reach the slope. Therefore, the first predetermined angle is set to a numerical value equal to or less than this maximum value.

When the pitch angle is greater than the first predetermined angle, the control unit 4 (position determination unit 4e) determines whether the distance from the position of the tractor 1 detected by the position detection unit 62 to the slope is equal to or less than a threshold value (S103 ). The position of the tractor 1 is the position of the positioning antenna 6, so there is one point. The position of the slope indicates a predetermined range. Therefore, for example, the shortest distance from the position of the tractor 1 to the slope corresponds to the "distance to the slope".

The purpose of step S103 is to determine whether part of the tractor 1 is positioned on the slope. Here, in the present embodiment, the position of the tractor 1 used in the determination in step S103 is strictly the position of the positioning antenna 6. Therefore, even if the position of the tractor 1 is not on the slope, The front of tractor 1 may be located on the slope (see FIG. 6 when tractor 1 is at P1). For example, when the positioning antenna 6 is attached to the front part of the tractor 1, or when a value obtained by offsetting the detection result of the position detection unit 62 to the front is handled as the position of the tractor 1, the position of the tractor 1 A determination may be made as to whether the position is located on the slope.

Next, the control unit 4 determines whether or not the field edge work setting is valid (S104). The field edge work is a setting for performing work by the work implement 3 to the edge of the field (that is, the boundary between the field and the slope). By performing a predetermined operation on the monitor device 14 or the wireless communication terminal 46, the user can switch between enabling and disabling the field-end work setting. The control unit 4 makes the determination in step S104 based on the user's settings.

When the field edge work setting is disabled, there is no need to perform work to the edge of the field, so the control unit 4 (elevating control unit 4b) raises the work implement 3 to the retracted position (S105).

On the other hand, when the field edge work setting is valid, the control unit 4 (the position calculation unit 4f) determines the lift start position (S106). The lift start position is a position at which the work implement 3 starts to lift. In FIG. 6, P2 corresponds to the ascent start position. The ascending start position is determined based on, for example, the position of the slope (boundary position between the slope and the field), the length of the work implement 3 in the vehicle length direction, the vehicle speed detected by the vehicle speed sensor 53, the engine rotation speed, and the like. be done. The position of the slope is used to calculate the ascending start position for preventing the work implement 3 from colliding with the slope. In addition, as the length of the work implement 3 in the vehicle length direction increases, the work is performed at a position farther rearward from the positioning antenna 6, so the lift start position is a position farther from the field. . Since the output of the hydraulic pump can be ensured as the vehicle speed and the engine rotation speed increase, the work implement 3 can be raised in a short time. Therefore, the time required from the start of lifting of the work implement 3 to the height at which the work implement 3 does not collide with the slope is shortened. When the vehicle speed is high, the time required for the tractor 1 to approach the slope is shortened. In consideration of the above, a rise start position is determined to widen the range in which the work is performed within a range in which the work implement 3 does not collide with the slope.

Then, the control unit 4 determines whether or not the position of the tractor 1 has reached the rise start position (S107). ) starts lifting the work implement 3 (S105, FIG. 6). As described above, it is possible to prevent the working machine 3 from colliding with the slope while working up to the edge of the field. Also, it is possible to prevent the work machine 3 from colliding with the road surface after the tractor 1 reaches the road.

In this way, when the field edge work is effective, the tractor 1 reaching the lift start position corresponds to the first position condition. On the other hand, when field edge work is disabled, the first position condition corresponds to the distance from the position of the tractor 1 to the position of the slope being equal to or less than the threshold. Note that a first position condition different from these may be set.

Next, with reference to FIGS. 7 and 8, control for automatically lowering the work implement 3 when going from the road to the field (hereinafter referred to as work implement lowering control) will be described. This control is also performed by the working machine lifting control device 80 .

First, the control unit 4 determines whether or not the work implement lowering control is effective (S201). As with the work implement ascending control described above, the user can switch between enabling and disabling the work implement lowering control by performing a predetermined operation on the monitor device 14 or the wireless communication terminal 46 . The control unit 4 makes the determination in step S201 based on the user's settings.

When the work implement lowering control is valid, the control unit 4 (angle determination unit 4d) determines whether the pitch angle detected by the inertia measurement unit 61 is negative and the absolute value is greater than the second predetermined angle ( S202). Here, when going from the road to the field, the tractor 1 descends the slope, so the front part of the tractor 1 is lower than the rear part, and the pitch angle is negative. After the front wheels 7 reach the slope, the absolute value of the pitch angle gradually increases, and when the rear wheels 8 reach the slope, the absolute value of the pitch angle reaches its maximum value. Here, the purpose of the work implement lift control is to lift the work implement 3 at the timing when the tractor 1 approaches the slope. On the other hand, in the work implement lowering control, as shown in FIG. 8, the purpose is to lower the work implement 3 at the timing when the tractor 1 approaches the field. Therefore, in the work implement lowering control, it is not necessary to detect a state in which only the front wheels of the tractor 1 are positioned on the slope. For example, as indicated by P11 in FIG. do it. Therefore, the second predetermined angle may be set to a value close to the maximum value. That is, the second predetermined angle may be larger than the first predetermined angle. However, the first predetermined angle and the second predetermined angle may be the same.

When the pitch angle is larger than the second predetermined angle, the control section 4 (position determination section 4e) determines whether or not the position of the tractor 1 detected by the position detection section 62 is on the slope (S203). As described above, the purpose of the work implement lowering control is to lower the work implement 3 when the tractor 1 approaches the field, so there is no need to detect that the tractor 1 has approached the slope (step A threshold like S103 is unnecessary). Therefore, in this embodiment, the position of the tractor 1 on the slope corresponds to the second position condition. However, step S203 may be the same process as step S103. Note that a second position condition different from these may be set.

When the pitch angle and the position of the tractor 1 satisfy the above two conditions, the control section 4 (the position calculation section 4f) determines the descent start position (S204). The descent start position is a position where the work implement 3 starts to be lowered. In FIG. 8, P12 corresponds to the descent start position. The descent start position is determined based on, for example, the position of the slope (boundary position between the slope and the field), the length of the work implement 3 in the vehicle length direction, the vehicle speed detected by the vehicle speed sensor 53, the engine speed, and the like. be done. The method of using each data is the same as the calculation of the ascent start position. Further, the distance detected by the distance detection sensor 63 is further used in the calculation of the descent start position in this embodiment. For the tractor 1 traveling on the slope, since the field is inclined, the distance to the edge of the field can be specified based on the reflected wave. As a result, the distance to the edge of the field can be detected more accurately, and a more appropriate descent start position can be determined. Instead of using the detection result of the distance detection sensor 63, the distance to the edge of the field may be calculated based on the position of the tractor 1 and the previously stored slope position (latitude and longitude information). . Considering the above, the descent start position is determined so that the work implement 3 is lowered as close to the edge of the field as possible within the range where the work implement 3 does not collide with the slope.

Then, the control unit 4 determines whether or not the position of the tractor 1 has reached the descent start position (S205). ) starts lowering the work implement 3 (S206, FIG. 8). As described above, it is possible to prevent the working machine 3 from colliding with the slope while working up to the edge of the field.

It should be noted that the control unit 4 (travel control unit 4a) may stop or decelerate the tractor 1 in the case where field edge work is effective in work implement ascending control, or in the work implement descending control. As a result, work can be performed up to just before the boundary between the field and the slope. Note that this function may also be switchable between valid and invalid.

Next, with reference to FIG. 9, the control (descent prohibition control, automatic top-up control) performed when the tractor 1 is outside the field will be described.

First, the control unit 4 (position determination unit 4e) determines whether the position of the tractor 1 detected by the position detection unit 62 is on the road outside the field (S301). As described above, the position of the road outside the field is registered in advance and stored in the wireless communication terminal 46 or the like.

Next, the control unit 4 determines whether or not the tractor 1 is running based on the detection result of the vehicle speed sensor 53 (S302).

When the tractor 1 is located on the road outside the farm field and the tractor 1 is running, the control unit 4 determines whether or not the descent prohibition control is effective (S303). The lowering prohibition control is a control that prohibits lowering of the working implement 3 even if the user instructs lowering of the working implement 3 as long as the tractor 1 is traveling outside the field. By enabling the descent prohibition control, the work machine 3 does not actually move down even when the work machine 3 is instructed to be lowered due to a user's operation error or the like, so that the work machine 3 can be prevented from being damaged. As with other controls, the user can switch between enabling and disabling the descent prohibition control by performing a predetermined operation on the monitor device 14 or the wireless communication terminal 46 . The control unit 4 makes the determination in step S303 based on the user's settings.

When the descent prohibition control is valid, the control unit 4 prohibits the work implement 3 from moving down even if the user instructs the work implement 3 to move down as long as the tractor 1 is traveling outside the field (S304).

Next, the control unit 4 determines whether or not the automatic top-up control is valid regardless of whether the descent prohibition control is valid or invalid (S305). The automatic maximum height control is a control that maximizes the height of the work implement 3 as long as the tractor 1 is traveling outside the field. By enabling the automatic top-up control, it is possible to more reliably prevent the work implement 3 from coming into contact with the road, and even if the user forgets to raise the work implement 3, the work implement 3 can be raised. can be raised. As with other controls, the user can switch between enabling and disabling automatic top-up control by performing a predetermined operation on the monitor device 14 or wireless communication terminal 46 . It should be noted that the descent prohibition control and the automatic top-up control can be independently switched between valid and invalid. The control unit 4 makes the determination in step S305 based on the user's settings.

When the automatic top-up control is valid, the controller 4 raises the work implement 3 to the top-up position if the current height of the work implement 3 is not at the top-up position (S306).

It should be noted that the work implement lift control, work implement lowering control, lowering inhibition control, and automatic top-up control can be enabled or disabled for each work implement 3 . As a result, even when the work implement 3 attached to the tractor 1 is changed, the previous settings can be maintained. In addition, recommended settings may be registered in advance for each work machine 3 according to the characteristics of the work machine 3 . In place of or in addition to the setting for each working machine 3, it may be possible to set whether these controls are valid or invalid for each field.

As described above, the work implement elevation control device 80 of the present embodiment includes the inertia measurement unit 61, the position detection section 62, the angle determination section 4d, the position determination section 4e, and the elevation control section 4b. Prepare. The inertial measurement unit 61 detects the pitch angle of the tractor 1 with the positive rotation direction in which the front portion of the tractor 1 moves upward. The position detector 62 detects the position of the tractor 1 using a satellite positioning system. The angle determination section 4d determines whether or not the pitch angle detected by the inertial measurement unit 61 is greater than the first predetermined angle. The position determination unit 4e determines whether the position of the tractor 1 detected by the position detection unit 62 satisfies the first position condition with respect to the position of the slope that connects the outside of the farm field and the farm field at a position higher than the field. judge. When the angle determining unit 4d determines that the pitch angle is greater than the first predetermined angle and the position determining unit 4d determines that the position of the tractor 1 satisfies the first positional condition, the elevation control unit 4b moves the working machine. 3 is raised to the retracted position.

As a result, whether or not to raise the work implement 3 to the retracted position is determined based on not only the pitch angle of the tractor 1 but also the position of the tractor 1. Therefore, even if the tractor 1 is tilted due to, for example, irregularities in the field, the work can be performed. Machine 3 does not rise to the retracted position. Therefore, the working machine 3 can be raised to the retracted position at the timing when the tractor 1 is surely moving up the slope to the outside of the field.

In addition, the work implement lifting control device 80 includes a vehicle speed sensor 53 and a position calculator 4f. A vehicle speed sensor 53 detects the vehicle speed of the tractor 1 . In the position calculation unit 4f, the angle determination unit 4d determines that the pitch angle is negative and the absolute value of the pitch angle is greater than the second predetermined angle, and the position of the tractor 1 satisfies the second position condition with respect to the position of the slope. When the position determination unit 4e determines that the condition is satisfied, the lowering start position of the work implement 3 is calculated based on the position of the slope and the vehicle speed detected by the vehicle speed sensor 53. The lift control unit 4b starts lowering the work implement 3 at the lowering start position calculated by the position calculator 4f.

As a result, the working machine 3 can be prevented from coming into contact with the slope, and the working machine 3 can be lowered to a position near the edge of the field on the slope side.

The work implement lifting control device 80 of the above embodiment includes a distance detection sensor 63 that detects the distance to an object in front or in front and below. The position calculator 4f calculates the descent start position based on the distance detected by the distance detection sensor 63 in addition to the position of the slope and the vehicle speed.

As a result, a more appropriate descent start position can be calculated, so that the work implement 3 can be lowered to a desired position with high accuracy.

Although the preferred embodiments of the present invention have been described above, the above configuration can be modified, for example, as follows.

The processing performed by at least one of the angle determination unit 4d, the position determination unit 4e, and the position calculation unit 4f may be performed by the wireless communication terminal 46 instead of the control unit 4 of the tractor 1. FIG.

In the above-described embodiment, the inertial measurement unit 61 is configured to detect the pitch angle of the tractor 1, but a sensor having another configuration may be used as long as it can detect at least the pitch angle.

In the above-described embodiment, the detection result of the distance detection sensor 63 is used to calculate the descent start position, but instead or in addition, it may be used to calculate the ascent start position.

In the above-described embodiment, the field edge work, the work implement lowering control, the lower stage prohibition control, and the automatic top-up control can be switched between valid and invalid. It does not have to have a function.

In the above embodiment, an example of using a plurality of data to calculate the ascending start position and descending start position has been described. may

1 tractor 4 control unit 4b elevation control unit 61 inertial measurement unit (angle sensor)
62 position detector 63 distance detection sensor 80 working machine lifting control device

Claims (3)

an angle sensor for detecting a pitch angle of a work vehicle to which the work implement can be attached;
a position detection unit that detects the position of the work vehicle using a satellite positioning system;
an angle determination unit that determines whether the pitch angle detected by the angle sensor is greater than a first predetermined angle;
When the angle determination unit determines that the pitch angle is greater than the first predetermined angle, the distance from the current position of the work vehicle to the slope connecting the outside of the farm field and the farm field at a position higher than the field is a threshold value. a position determination unit that determines whether
a position calculation unit that determines a lift start position for lifting the work implement when the position determination unit determines that the distance is equal to or less than a threshold;
an elevation control unit that raises the working machine to a retracted position when the position of the work vehicle reaches the elevation start position when heading from the agricultural field to the outside of the agricultural field ;
A work machine lifting control device comprising: an angle sensor for detecting a pitch angle of a work vehicle to which the work implement can be attached;
a position detection unit that detects the position of the work vehicle using a satellite positioning system;
an angle determination unit that determines whether the pitch angle detected by the angle sensor is greater than a second predetermined angle ;
a position determination unit that determines whether the current position of the working vehicle is at the position of the slope that connects the outside of the farm field, which is higher than the farm field, and the farm field;
The position determination unit determines that the pitch angle is greater than the second predetermined angle when heading toward the farm field from outside the farm field, and that the work vehicle is positioned on the slope. a position calculation unit that determines a descent start position for descent of the work implement when it is determined that
A work machine lifting control device comprising : The work machine lifting control device according to claim 2,
A working machine lifting control device, comprising: a lifting control section that starts lowering of the working machine when the working vehicle reaches the lowering start position .

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