Motion control system for work vehicle

Abstract

To provide a motion control system for a work vehicle capable of maintaining a constant bucket angle when an arm is rotated to raise and / or lower the bucket.SOLUTION: A motion control system 1 for a work vehicle includes an arm 18 and a bucket 22 attached to the arm 18. The system includes a control unit 30 and a first angle sensor 42 that measures the angle of the bucket 22. While the arm 18 is rising and / or lowering, the control unit 30 refers to the angle of the bucket 22 output by the first angle sensor 42 and adjusts the angle of the bucket 22 so that the angle of the bucket 22 remains constant.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a motion control system for a work vehicle. [Background technology]

[0002] "Crawler loaders" (also called "track loaders") are known as working vehicles such as construction machinery. Crawler loaders have an arm, and an attachment such as a bucket can be attached to the tip of the arm. Crawler loaders store soil and sand in a bucket and raise or lower the arm to move the soil and sand stored in the bucket in an up and down direction. Here, it is sometimes preferable to maintain a constant angle of the bucket when the arm is raised or lowered.

[0003] Patent Document 1 describes a work vehicle equipped with a function for raising an arm while maintaining the angle of the bucket. Fig. 9 is a diagram shown for explaining the work vehicle 901 described in Patent Document 1. Fig. 10 is a diagram shown for explaining the function of raising an arm while maintaining the angle of the bucket, which is equipped to the work vehicle 901 described in Patent Document 1.

[0004] The work vehicle 901 is equipped with a bell crank 908 rotatably mounted approximately in the center of the arm 905, a tilt cylinder 907 that connects one end 908A of the bell crank 908 to the work vehicle 901, and a connecting link 912 (see Figure 10) that connects the other end 908B of the bell crank 908 to the back of the bucket 911.

[0005] One end of the tilt cylinder 907 is rotatably attached to a position O below the position at which the base P of the arm 905 is attached to the work vehicle 901. The bucket 911 angle maintaining function, as shown in Fig. 10, is to raise the arm 905 while maintaining a substantially constant angle of the bucket 911 by raising the arm 905 with the tilt cylinder 907 in a fixed state. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-343631 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the bucket 911 angle maintaining function described in the prior art document had an issue in that when the angle at which the arm 905 is raised is large, the angle of the bucket 911 at the top position may shift toward the embracing direction (the tip of the bucket 911 points upward).

[0008] The present invention has been made in consideration of these problems, and has an object to provide an operation control system for a work vehicle that is capable of maintaining a constant bucket angle when the arm is rotated to raise and / or lower the bucket. [Means for solving the problem]

[0009] The motion control system for a work vehicle of this embodiment is a motion control system for a work vehicle equipped with an arm and a bucket attached to the arm, and includes a control unit and a first angle sensor that measures the angle of the bucket. The control unit refers to the angle of the bucket output by the first angle sensor while the arm is rising and / or while the arm is lowering, and adjusts the angle of the bucket so that the angle of the bucket is constant.

[0010] A work vehicle motion control system according to another aspect of the present embodiment is a work vehicle motion control system including an arm and a bucket attached to the arm, and includes a control unit, a memory unit, a first angle sensor that measures the angle of the bucket, and a third angle sensor that measures the angle of the arm. The memory unit stores the angle of the bucket at a target position as first angle information, and stores the angle of the arm at the target position as third angle information. The control unit transitions the angle of the arm to the angle value stored as the third angle information, and transitions the angle of the bucket to the angle value stored as the first angle information.

[0011] The motion control system for a work vehicle of this embodiment is a motion control system for a work vehicle including an arm and a bucket attached to the arm, and includes a control unit, a memory unit, and a third angle sensor that measures the angle of the arm. The memory unit stores the angle of the arm at a stop position where the arm is stopped as third angle information. While the arm is being raised by an operator's operation, the control unit compares the angle of the arm output by the third angle sensor with the angle value of the third angle information stored in the memory unit, and stops the raising operation of the arm when the angle of the arm output by the third angle sensor becomes the same value as the angle value of the third angle information stored in the memory unit. Effect of the Invention

[0012] The operation control system for the work vehicle is configured so that the control unit refers to the bucket angle output by the first angle sensor while the arm is rising and / or lowering, and adjusts the bucket angle so that the bucket angle remains constant.

[0013] According to the motion control system for a work vehicle, it is possible to provide a motion control system for a work vehicle that is capable of maintaining a constant bucket angle when the arm is rotated to raise and / or lower the bucket. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing a work vehicle 10 equipped with a work vehicle motion control system 1 according to a first embodiment, as viewed obliquely from the front. [Diagram 2] 2A to 2C are diagrams shown for explaining the movements of an arm 18 and a bucket 22 in the motion control system 1 for a work vehicle according to the first embodiment. [Diagram 3] 1 is a block diagram showing a configuration of a motion control system 1 for a work vehicle according to a first embodiment. [Figure 4] 4 is a flowchart shown to explain the processing in the operation control system 1 for the work vehicle according to the first embodiment. [Diagram 5] 10A to 10C are diagrams shown for explaining the movements of an arm 18 and a bucket 22 in a motion control system 2 for a work vehicle according to a second embodiment. [Figure 6] 10 is a flowchart shown for explaining the processing in a motion control system 2 for a work vehicle according to a second embodiment. [Figure 7] 11A to 11C are diagrams shown for explaining the movements of an arm 18 and a bucket 22 in a motion control system 3 for a work vehicle according to a third embodiment. [Figure 8] 10 is a flowchart shown for explaining the processing in a motion control system 3 for a working vehicle according to a third embodiment. [Figure 9] FIG. 1 is a diagram shown for explaining a work vehicle 901 described in Patent Document 1. [Figure 10] FIG. 13 is a diagram for explaining a function of lifting an arm while maintaining the angle of a bucket, which is provided to a work vehicle 901 described in Patent Document 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The following describes a mode for carrying out the present invention (hereinafter, referred to as "embodiment"). The embodiment described below shows a preferred mode for carrying out the invention, and does not limit the invention according to the claims. Furthermore, not all of the elements and combinations thereof described in the embodiment are necessarily essential to the present invention.

[0016] 1. Embodiment 1 1.1.Work vehicles 1 is a view of a work vehicle 10 equipped with a work vehicle motion control system 1 according to embodiment 1, viewed obliquely from the front. Below, a "crawler loader" (also called a "track loader") equipped with an arm 18 and capable of mounting a bucket 22 on the tip of the arm 18 will be described as an example of the work vehicle 10 controlled by the work vehicle motion control system 1.

[0017] In addition, in the following description, as shown in FIG. 1, the side of work vehicle 10 on which bucket 22 is attached is referred to as the "front", the side opposite the side on which bucket 22 is attached is referred to as the "rear", the bottom side of work vehicle 10 is referred to as the "bottom", the side opposite the bottom is referred to as the "top", and the left side of work vehicle 10 when viewed from behind is referred to as the "left" and the right side is referred to as the "right".

[0018] As shown in FIG. 1, the work vehicle 10 has a main body frame 11, a pair of left and right traveling devices 12 attached to the main body frame 11 and configured with crawlers (endless tracks) 13, a work device 14 attached to the main body, and a cabin (symbol omitted) provided in the upper center of the main body frame 11.

[0019] The cabin is provided with an operator seat 17 on which an operator sits facing the front of the vehicle. Remote control levers 50 are provided on the left and right of the operator seat 17.

[0020] In the work vehicle 10, an operator seated on the operator seat 17 can operate a remote control lever 50 to raise or lower the arm 18 and also change the angle of the bucket 22.

[0021] For example, the arm 18 can be raised by tilting backward the remote control lever 50 located on the right side of the operator seat 17, and the arm 18 can be lowered by tilting the remote control lever 50 forward. Also, the bucket 22 can be rotated in a direction to hold it in place by tilting the remote control lever 50 to the left, and the bucket 22 can be rotated in a direction to dump it by tilting the remote control lever 50 to the right.

[0022] The working device 14 includes an arm 18 rotatably attached to the main body frame 11, an arm cylinder 19, a bucket 22 attached to the tip of the arm 18, and a bucket cylinder 23.

[0023] The arm cylinder 19 is attached straddling the main body frame 11 and the arm 18. By extending and retracting the arm cylinder 19, the arm 18 can be rotated to change the angle of the arm 18. The bucket cylinder 23 is attached straddling the arm 18 and the bucket 22. By extending and retracting the bucket cylinder 23, the angle of the bucket 22 can be changed.

[0024] As shown in FIG. 2, the work vehicle 10 has a first angle sensor 42, a second angle sensor 44, and a third angle sensor 46.

[0025] The first angle sensor 42 is installed on the bucket 22. The first angle sensor 42 measures the angle of the bucket 22. The second angle sensor 44 is installed at an appropriate position on the main body frame 11 of the work vehicle 10, for example, on the rear side of the main body frame 11. The second angle sensor 44 measures the angle that the work vehicle 10 makes with the ground. The third angle sensor 46 is installed on the arm 18. The third angle sensor 46 measures the angle of the arm 18.

[0026] The first angle sensor 42, the second angle sensor 44, and the third angle sensor 46 may be of any type, name, or measurement method as long as they are capable of measuring the angle of the location where the angle sensor is installed (for example, the angle of the bucket 22 in the case of the first angle sensor 42). Various sensors such as a gyro sensor or an inertial sensor can be used. As for the measurement method, various sensors such as a capacitance type or a piezoelectric type can be used. 1.2.Work vehicle motion control system

[0027] Next, we will explain the working vehicle motion control system 1. The working vehicle motion control system 1 is a system (hereinafter sometimes referred to as a "self-level Up & Down control system") that controls the bucket 22 attached to the tip of the arm 18 so that the angle of the bucket 22 remains constant when the arm 18 is raised or lowered.

[0028] Fig. 2 is a diagram shown to explain the movement of the arm 18 and the bucket 22 in the work vehicle motion control system 1 according to embodiment 1. Fig. 3 is a block diagram showing the configuration of the work vehicle motion control system 1 according to embodiment 1. Fig. 4 is a flowchart shown to explain the processing in the work vehicle motion control system 1 according to embodiment 1.

[0029] The self level Up & Down control system includes a control unit 30, an angle detection unit 40, and an operation unit, as shown in Fig. 3. The control unit 30 includes a memory unit 32. The angle detection unit 40 includes a first angle sensor 42, a second angle sensor 44, and a third angle sensor 46. The operation unit includes a remote control lever 50.

[0030] The angle control of the bucket 22 in the self-level Up & Down control system will be described with reference to Figs.

[0031] In the work vehicle operation control system 1, the control unit 30 refers to the angle of the bucket 22 output by the first angle sensor 42 while the arm 18 is rising and / or lowering, and adjusts the angle of the bucket 22 so that the angle of the bucket 22 remains constant.

[0032] Step S11 (see FIG. 4) is a step of acquiring the angle of the bucket 22 and storing it in the memory unit 32. The control unit 30 acquires the angle of the bucket 22 at the moment when an operator (reference number omitted) operates the bucket 22 and stops operating the bucket 22. The angle of the bucket 22 is measured by a first angle sensor 42 disposed in the bucket 22. The angle of the bucket 22 is stored in the memory unit 32 as first angle information.

[0033] In the following explanation, for convenience of explanation, with regard to the rotational direction of bucket 22, the "direction in which bucket 22 is embraced" may be referred to as the "direction in which the angle of bucket 22 increases," and the "direction in which bucket 22 is dumped" may be referred to as the "direction in which the angle of bucket 22 decreases."

[0034] In step S12, the operator operates the arm 18. The operator may operate the arm 18 to raise or lower the arm 18 (see FIG. 2). The arm 18 is operated by the operator operating the remote control lever 50 to extend or retract the arm cylinder 19.

[0035] If the bucket 22 is operated by the operator while the operator is operating the arm 18 ("Yes" in S13), the control unit 30 acquires the angle of the bucket 22 at the moment the operator stops operating the bucket 22. In addition, the acquired angle of the bucket 22 is stored in the memory unit 32 by the control unit 30 (see S11).

[0036] If the operator does not operate the bucket 22 while operating the arm 18 ("No" in S13), the control unit 30 adjusts the angle of the bucket 22 while continuing the operation of the arm 18 (raising or lowering the arm 18). The control unit 30 refers to the angle of the bucket 22 output by the first angle sensor 42, and adjusts the angle of the bucket 22 so that the angle of the bucket 22 is constant (see S14).

[0037] Specifically, control unit 30 adjusts the amount of pressure oil sent to bucket cylinder 23 so that the angle of bucket 22 output by first angle sensor 42 approaches the angle value of the first angle information stored in memory unit 32. This makes it possible to keep the angle of bucket 22 constant while arm 18 is moving.

[0038] The control unit 30 may refer to the angle of the bucket 22 output by the first angle sensor 42 and the angle of the work vehicle 10 output by the second angle sensor 44 disposed on the work vehicle 10, and adjust the angle of the bucket 22 so that the angle between the work vehicle 10 and the bucket 22 is constant. This makes it possible to raise or lower the arm 18 while keeping the angle of the bucket 22 constant, even when the work vehicle 10 is working on a slope.

[0039] When the arm 18 reaches a predetermined height, the operator ends the operation of the arm 18 (see S15).

[0040] The work vehicle motion control system 1 (self-level Up & Down control system) according to the first embodiment refers to the angle of the bucket 22 output by the first angle sensor 42, and adjusts the angle of the bucket 22, in other words, the length of the bucket cylinder 23, so that the angle of the bucket 22 remains constant. This makes it possible to provide a work vehicle motion control system 1 that can maintain the angle of the bucket 22 constant when the arm 18 is rotated to raise and / or lower the bucket 22.

[0041] A preferred embodiment of the work vehicle motion control system 1 (self-level Up & Down control system) according to the first embodiment refers to the angle of the bucket 22 output by the first angle sensor 42 and the angle of the work vehicle 10 output by the second angle sensor 44 provided on the work vehicle 10, and adjusts the angle of the bucket 22 so that the angle between the work vehicle 10 and the bucket 22 is constant. This provides the above-mentioned effects, and also makes it possible to raise or lower the arm 18 while keeping the angle of the bucket 22 constant, even when the work vehicle 10 is working on a slope.

[0042] 2. Embodiment 2 Next, we will explain the motion control system 2 for a work vehicle according to embodiment 2. The motion control system 2 for a work vehicle is a system in which a control unit 30 controls the transition of the positions of the arm 18 and the bucket 22 to target positions stored in a memory unit 32 (hereinafter, sometimes referred to as a "return to position control system").

[0043] In the work vehicle motion control system 2, the work vehicle 10 on which the motion control system 2 is mounted, and the elements that constitute the motion control system 2 are the same as those in the work vehicle motion control system 1 according to the first embodiment.

[0044] Therefore, in describing the work vehicle motion control system 2, parts that overlap with the work vehicle motion control system 1 of embodiment 1 will be omitted, and only parts that are different will be described.

[0045] Fig. 5 is a diagram shown for explaining the movement of the arm 18 and the bucket 22 in the work vehicle motion control system 2 according to embodiment 2. Fig. 6 is a flowchart shown for explaining the processing in the work vehicle motion control system 2 according to embodiment 2. Hereinafter, the control of the arm 18 and the bucket 22 in the return to position control system will be described with reference to FIGS.

[0046] In the work vehicle motion control system 2, the memory unit 32 stores the angle of the bucket 22 at the target position as first angle information, and stores the angle of the arm 18 at the target position as third angle information. The control unit 30 transitions the angle of the arm 18 to the angle value stored as the third angle information, and transitions the angle of the bucket 22 to the angle value stored as the first angle information.

[0047] In step S21, the angle of the arm 18 and the angle of the bucket 22 at the return position are stored in the memory unit 32 (see FIG. 3). Here, the return position is a target position reached as a result of the arm 18 and the bucket 22 transitioning under control of the control unit 30 (hereinafter, may be referred to as "automatic transition"). For example, in FIG. 5, it is the position of the arm 18 and the bucket 22 shown at the bottom among the positions of the two arms 18 and the bucket 22 drawn by dotted lines.

[0048] As a method for storing the angle of arm 18 and the angle of bucket 22 at the return position, an operator operates arm 18 and bucket 22 to move arm 18 and bucket 22 to the return position. After that, the angle of arm 18 is obtained by third angle sensor 46, and the angle of bucket 22 is obtained by first angle sensor 42, and these are stored in memory unit 32.

[0049] After the angle of the arm 18 at the return position is stored in the memory unit 32 as the third angle information and the angle of the bucket 22 is stored in the memory unit 32 as the first angle information, the "return to position" mode is activated (see S22). The "return to position" mode can be activated, for example, by the operator pressing one or more buttons provided on the remote control lever 50, or the like.

[0050] In step S23, control unit 30 compares the current angle of arm 18 with the angle value stored as the third angle information in memory unit 32. If the current angle of arm 18 is the same as the angle value stored as the third angle information in memory unit 32 or is smaller than the angle value stored as the third angle information in memory unit 32 ("No" in step S23), it resets the "return to position" mode and waits until the "return to position" mode is activated again.

[0051] If the current angle of arm 18 is greater than the angle value stored in memory unit 32 as the third angle information ("Yes" in step S23), control unit 30 performs the lowering operation of arm 18 (see step S24).

[0052] In step S25, the current angle of bucket 22 is compared with the angle value stored as the first angle information in memory unit 32. If the current angle of bucket 22 is the same as the angle value stored as the first angle information in memory unit 32 or is greater than the angle value of the first angle information stored in memory unit 32 ("No" in step S25), the process returns to step S24 and the lowering operation of arm 18 continues.

[0053] If the current angle of bucket 22 is smaller than the angle value of the first angle information stored in memory unit 32 ("Yes" in step S25), control unit 30 performs an operation to tuck in bucket 22 in parallel with the operation of lowering arm 18. The operation of tuck in bucket 22 is an operation of rotating bucket 22 in a direction to tuck in bucket 22.

[0054] As a result, even if bucket 22 faces in the dump direction (the tip of bucket 22 faces downward from horizontal) in the initial position, it is possible to prevent the tip of bucket 22 from contacting the ground when arm 18 is lowered. In addition, it is possible to prevent soil and sand contained in bucket 22 from falling out of bucket 22 when the tip of bucket 22 faces downward as arm 18 is lowered.

[0055] In step S27, when the angle of arm 18 becomes equal to the angle value stored in memory unit 32 as the third angle information, the lowering operation of arm 18 is completed.

[0056] In step S28, the current angle of the bucket 22 is compared with the angle value stored in the memory unit 32 as the first angle information.

[0057] If the current angle of the bucket 22 is greater than the angle value stored as the first angle information in the memory unit 32 ("Yes" in step S28), the process proceeds to step S29, and a dump operation of the bucket 22 is performed. The dump operation of the bucket 22 is an operation of rotating the bucket 22 in the dump direction.

[0058] The dumping operation of the bucket 22 is performed by referring to the angle of the bucket 22 output by the first angle sensor 42. When the angle of the bucket 22 matches the angle value stored in the memory unit 32 as the first angle information, the dumping operation of the bucket 22 is terminated.

[0059] If the current angle of bucket 22 is smaller than the angle value stored in memory unit 32 as the first angle information ("No" in step S28), the process proceeds to step S30, and a hoarding operation is performed for bucket 22. As described above, the hoarding operation for bucket 22 is an operation for rotating bucket 22 in the hoarding direction.

[0060] The hoarding operation of bucket 22 is performed by referring to the angle of bucket 22 output by first angle sensor 42. When the angle of bucket 22 matches the angle value stored in memory unit 32 as first angle information, the hoarding operation of bucket 22 is terminated.

[0061] By the dumping operation of the bucket 22 or the hoarding operation of the bucket 22, the angle of the bucket 22 can be adjusted to the angle of the bucket 22 at the return position (target position).

[0062] Thereafter, the process proceeds to step S31, where the operation of the bucket 22 is completed.

[0063] In the work vehicle motion control system 2 (return to position control system), the control unit 30 transitions the angle of the arm 18 to the angle value stored in the memory unit 32 as third angle information. Also, the control unit 30 transitions the angle of the bucket 22 to the angle value stored in the memory unit 32 as first angle information.

[0064] This enables the control unit 30 to transition the arm 18 and the bucket 22 to the return position (target position).

[0065] 3. Embodiment 3 The following describes a working vehicle motion control system 3 according to embodiment 3. The working vehicle motion control system 3 is a system that controls the arm 18 so that it does not rise above a predetermined height (hereinafter, may be referred to as an "arm height limit control system").

[0066] In the work vehicle motion control system 3, the work vehicle 10 on which the motion control system 3 is mounted, and the elements that constitute the motion control system 3 are the same as those in the work vehicle motion control system 1 according to the first embodiment.

[0067] Therefore, in explaining the working vehicle motion control system 3, parts that overlap with the working vehicle motion control system 1 of embodiment 1 will be omitted, and only parts that are different will be explained.

[0068] Fig. 7 is a diagram shown for explaining the movement of the arm 18 and the bucket 22 in the work vehicle motion control system 3 according to embodiment 3. Fig. 8 is a flowchart shown for explaining the processing in the work vehicle motion control system 3 according to embodiment 3. The control of the arm 18 and the bucket 22 in the arm height limit control system will be described with reference to FIGS.

[0069] In the work vehicle motion control system 3, the memory unit 32 stores the angle of the arm 18 at the stop position where the arm 18 is stopped as third angle information. While the arm 18 is being raised by the operator's operation, the control unit 20 compares the angle of the arm 18 output by the third angle sensor 46 with the angle value stored as the third angle information in the memory unit 32. The control unit 20 stops the raising operation of the arm 18 when the angle of the arm 18 output by the third angle sensor 46 becomes the same value as the angle value of the third angle information stored in the memory unit 32.

[0070] In step S41, the angle of the arm 18 at the stop position is stored as third angle information in the memory unit 32 (see FIG. 3). Here, the stop position is a position at which the arm 18 is stopped by the arm height limit control system. For example, it is the position of the arm 18 and the bucket 22 depicted by solid lines in FIG. 7.

[0071] As a method for storing the angle of the arm 18 at the stop position, an operator operates the arm 18 and the bucket 22 to move the arm 18 and the bucket 22 to the stop position, and then the angle of the arm 18 is obtained by the third angle sensor 46 and the angle of the arm 18 is stored in the memory unit 32.

[0072] Alternatively, the work vehicle 10 may be equipped with an input unit (not shown), and the operator may input the angle of the arm 18 at the stop position via the input unit.

[0073] In step S42, the operator operates the arm 18. The operation of the arm 18 is a normal operation of the arm 18. That is, the operator can raise or lower the arm 18 when working using the work vehicle 10. The speed of the arm 18 when raising the arm 18 is a first speed. In addition to operating the arm 18, the operator may perform an operation to change the angle of the bucket 22.

[0074] In step S43, the control unit 30 acquires the angle of the arm 18 output by the third angle sensor 46, and compares it with the angle value stored as the third angle information in the memory unit 32. If the difference between the current angle of the arm 18 and the angle value stored as the third angle information in the memory unit 32 is greater than the predetermined angle ("No" in S43), the process returns to step S42. The operator can continue operating the arm 18.

[0075] If the difference between the current angle of the arm 18 and the angle value stored in the memory unit 32 as the third angle information is equal to or less than the predetermined angle ("Yes" in S43), the process proceeds to step S44. The control unit 30 limits the lifting speed of the arm 18 to a slow speed. Specifically, the control unit 30 limits the lifting speed of the arm 18 to a second speed slower than the first speed by reducing the amount of pressurized oil fed to the arm cylinder 19. Additionally, a warning that the arm height is approaching the height limit value may be displayed on a display unit (not shown) installed in the cabin.

[0076] In step 45, the control unit 30 acquires the angle of the arm 18 output by the third angle sensor 46, and compares it with the angle value stored as the third angle information in the memory unit 32. If the difference between the current angle of the arm 18 and the angle value stored as the third angle information in the memory unit 32 is greater than 0° ("No" in S45), the process returns to step S42. The operator can continue operating the arm 18.

[0077] If the difference between the current angle of the arm 18 and the angle value stored as the third angle information in the memory unit 32 is 0° or less ("Yes" in S45), the process proceeds to step S46. The control unit 30 stops the lifting operation of the arm 18. Specifically, the pressure oil sent to the arm cylinder 19 is stopped.

[0078] The work vehicle operation control system 3 (height limit control system) of embodiment 3 compares the angle output by a third angle sensor 46 arranged on the arm 18 with the angle value stored as third angle information in the memory unit 32, and when the angle output by the third angle sensor 46 and the angle value stored as third angle information in the memory unit 32 become the same value, the control unit 30 stops the raising operation of the arm 18.

[0079] This makes it possible to prevent the arm 18 from colliding with an obstacle above when the work vehicle 10 is used in a place with height restrictions, such as indoors or where there is an obstacle above.

[0080] Furthermore, according to a preferred embodiment of the work vehicle operation control system 3 (height limit control system) of embodiment 3, when the difference between the angle output by the third angle sensor 46 and the angle value stored in the memory unit 32 as third angle information becomes equal to or less than a predetermined angle, the control unit 30 limits the lifting speed of the arm to a second speed which is slower than the first speed.

[0081] This makes it possible to more effectively prevent the arm 18 from colliding with an obstacle above.

[0082] In the above-described work vehicle motion control system 3 according to the third embodiment, the case has been described where the lifting motion of the arm 18 is stopped by referring to the angle of the arm 18 output by the third angle sensor 46. However, the lifting motion of the arm 18 may be stopped by using the angle of the bucket 22 output by the first angle sensor 42 disposed on the bucket 22 in addition to the angle of the arm 18.

[0083] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0084] Reference Signs List 1, 2, 3... work vehicle operation control system, 10... work vehicle, 18... arm, 22... bucket, 30... control unit, 32... memory unit, 42... first angle sensor, 44... second angle sensor, 46... third angle sensor

Claims

1. A motion control system for a work vehicle including an arm and a bucket attached to the arm, A control unit and a first angle sensor that measures an angle of the bucket, the control unit refers to the bucket angle output by the first angle sensor while the arm is rising and / or while the arm is lowering, and adjusts the bucket angle so that the bucket angle is constant.

2. 2. The work vehicle motion control system according to claim 1, The control unit further includes a second angle sensor that measures an angle between the work vehicle and a ground contact surface, the control unit refers to the angle of the bucket output by the first angle sensor and the angle of the work vehicle output by the second angle sensor, and adjusts the angle of the bucket so that the angle between the work vehicle and the bucket is constant.

3. A motion control system for a work vehicle including an arm and a bucket attached to the arm, a control unit, a memory unit, a first angle sensor that measures an angle of the bucket, and a third angle sensor that measures an angle of the arm, the memory unit stores an angle of the bucket at the target position as first angle information and stores an angle of the arm at the target position as third angle information; the control unit transitions the angle of the arm to the angle value stored as the third angle information, and transitions the angle of the bucket to the angle value stored as the first angle information.

4. A motion control system for a work vehicle including an arm and a bucket attached to the arm, a control unit, a storage unit, and a third angle sensor that measures an angle of the arm, the storage unit stores an angle of the arm at a stop position where the arm is stopped as third angle information; the control unit, while the arm is being raised by the operation of an operator, compares the angle of the arm output by the third angle sensor with the angle value stored as the third angle information in the memory unit, and stops the raising operation of the arm when the angle of the arm output by the third angle sensor becomes the same as the angle value of the third angle information stored in the memory unit.

5. 5. The operation control system for a work vehicle according to claim 4, the control unit, when a difference between the angle of the arm output by the third angle sensor and the angle value stored in the memory unit as the third angle information becomes equal to or less than a predetermined angle, sets the lifting speed of the arm to a second speed which is slower than the first speed which is the lifting speed up to that point.

Images