Control system, method for a loading machine and loading machine

Abstract

One aspect of the present application is a control system of a work machine, which is a control system of a work machine having a work device including a work tool and a movable support portion that changes a posture of the work tool, the control system including a controller that discriminates the presence or absence of a load on the work tool and determines a target work device posture that indicates a target posture of the work tool based on a result of the discrimination of the presence or absence of the load.

Description

Technical Field

[0001] This invention relates to a control system and method for an loading machine, as well as the loading machine itself. This application claims priority based on Japanese Patent Application No. 2020-196924, filed on November 27, 2020, the contents of which are incorporated herein by reference. Background Technology

[0002] Patent Document 1 discloses a lever-type signal generating device that generates a control signal corresponding to the tilting amount of a lever by tilting it. Furthermore, this lever-type signal generating device has the following functions: when the lever reaches the end of its stroke, it maintains the lever in a tilted state and restores the tilting state to a neutral state based on signals from predetermined sensors, etc. Therefore, according to this lever-type signal generating device, even after the operator removes their hand from the lever after it reaches the end of its stroke, a control signal corresponding to the tilting amount and tilting direction of the lever is continuously output. Therefore, for example, when operating the working device of a wheel loader using this lever-type signal generating device, the operator can concentrate on the driving operation of the wheel loader when simultaneously performing multiple different operations such as driving the wheel loader while raising the working device.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-105618 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] As described above, according to the lever-type signal generating device described in Patent Document 1, as long as the operating lever is tilted until it remains tilted, even if the hand is released, the working tool, such as a bucket, can be moved to a predetermined height and automatically stopped.

[0008] However, according to a specific work cycle, after a wheel loader uses its bucket or other tools to excavate sand or other excavated objects, it raises the tools to load the excavated material into a transport vehicle. Then, it lowers the tools into a digging position and repeats the excavation and shoveling of the excavated material. In such a work cycle, for example, if the tool's position could automatically change to a digging position based on the lowering operation, the operation could be made more labor-saving. However, the operation of lowering a rising tool is not limited to when the tool is unloaded; it can also be performed when the tool is loaded. When loaded, if the tool's position automatically changes to a digging position, there is a possibility of inappropriate spillage of the excavated material.

[0009] The present invention was made in view of the above circumstances, and its object is to provide a control system, method and loading machine for a loading machine that can appropriately determine the target posture of a working tool under automatic control of the tool's posture.

[0010] Solution for solving the problem

[0011] The first aspect of the present invention is a control system for a loading machine having a working device including a working tool and a movable support for changing the posture of the working tool, and a controller. The controller is programmed to perform the following processes: The controller determines whether the working tool is loaded or not. Based on the determination result of whether the loading tool is loaded or not, the controller determines the posture of the target working device, representing the target posture of the working tool.

[0012] A second aspect of the present invention is a method executed by a controller for controlling a loading mechanism having a working device including a working tool and a movable support for changing the posture of the working tool, and comprising the following steps: The first step is to determine whether the working tool is loaded with cargo. The second step is to determine the target working device posture, representing the target posture of the working tool, based on the determination result of the presence or absence of cargo.

[0013] A third aspect of the present invention is a work vehicle comprising: a work device having a work tool and a movable support for changing the posture of the work tool; an operation unit for operating the movable support; and a controller. The controller is programmed to perform the following processes: The controller determines whether the work tool is carrying a load. When the operation unit is operated as specified, the controller determines a target work device posture representing a target posture of the work tool based on the determination of the load presence or absence. The controller outputs a control command for the movable support in such a manner that the target work device posture is achieved.

[0014] Invention Effects

[0015] According to the present invention, a control system, a method, and a loading machine are provided that can appropriately determine the target posture of a working tool when the posture of the working tool is automatically controlled. Attached Figure Description

[0016] Figure 1 This is a side view showing the loading mechanism of the embodiment.

[0017] Figure 2 This is a side view showing an example of the operation of the loading mechanism in the embodiment.

[0018] Figure 3 This is a side view showing other examples of the loading mechanism in the embodiment.

[0019] Figure 4 This is a side view showing other examples of the loading mechanism in the embodiment.

[0020] Figure 5 This is a block diagram illustrating an example of the configuration of the control system for the loading mechanism in the embodiment.

[0021] Figure 6 This is a perspective view showing an example of the configuration of the boom operating device according to the embodiment.

[0022] Figure 7 This is a schematic block diagram illustrating the structure of the controller in the implementation method.

[0023] Figure 8 This is a schematic diagram illustrating an example of the operation of the loading mechanism in the embodiment.

[0024] Figure 9 This is a flowchart illustrating an example of the controller's operation in an implementation method. Detailed Implementation

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that in the various figures, the same reference numerals are used for the same or corresponding structures and descriptions are omitted as appropriate.

[0026] In this embodiment, a local coordinate system is established within the loading mechanism 1, and the positional relationships of each part are explained while referring to this local coordinate system. In the local coordinate system, the first axis extending along the left-right direction (vehicle width direction) of the loading mechanism 1 is designated as the X-axis, the second axis extending along the front-back direction of the loading mechanism 1 is designated as the Y-axis, and the third axis extending along the up-down direction of the loading mechanism 1 is designated as the Z-axis. The X-axis is orthogonal to the Y-axis. The Y-axis is orthogonal to the Z-axis. The Z-axis is orthogonal to the X-axis. The +X direction is the right direction, and the -X direction is the left direction. The +Y direction is the front direction, and the -Y direction is the back direction. The +Z direction is the up direction, and the -Z direction is the down direction.

[0027] [Overview of the loading mechanism]

[0028] Figure 1 This is a side view showing the loading machine 1 of the embodiment. The loading machine 1 of the embodiment is, for example, a wheel loader. In the following description, the loading machine 1 will be appropriately referred to as a wheel loader 1.

[0029] like Figure 1 As shown, the wheel loader 1 has a body 2, a cab 3, a running gear 4, and a working device 10. The wheel loader 1 travels at the work site via the running gear 4. The wheel loader 1 uses the working device 10 to perform operations at the work site. The wheel loader 1 can use the working device 10 to perform operations such as digging, loading, transporting, and snow removal.

[0030] The cab 3 is supported on the vehicle body 2. Inside the cab 3 are a driver's seat 31 for the operator, an operating device 32 (described later), and an input display unit 34.

[0031] The traveling mechanism 4 has rotatable wheels 5. The wheels 5 support the vehicle body 2. The wheeled loader 1 can travel on the road surface RS via the traveling mechanism 4. It should be noted that... Figure 1 The image shows only the front wheel 5F and the rear wheel 5R on the left side.

[0032] The working device 10 is supported on the vehicle body 2. The working device 10 consists of a bucket 12, which is an example of a working tool, and a movable support 17 that allows the position and orientation of the bucket 12 to change. Figure 1 In the example shown, the movable support 17 includes a boom 11, a pair of boom cylinders 13, a bucket cylinder 14, a double boom crank 15, and a connecting rod 16.

[0033] The boom 11 is supported in a manner that allows it to rotate relative to the vehicle body 2, and adjusts according to the extension and retraction of the boom cylinder 13. Figures 1-4 As shown, it moves in the vertical direction. The boom cylinder 13 is an actuator that generates power to move the boom 11, with one end connected to the vehicle body 2 and the other end connected to the boom 11. When the operator operates the boom operating device 33, the boom cylinder 13 extends or retracts. This causes the boom 11 to move in the vertical direction. The boom cylinder 13 is, for example, a hydraulic cylinder.

[0034] The bucket 12 is a working tool with a shovel tip 12T used for digging and loading objects such as sand and soil. The bucket 12 is rotatably connected to the boom 11 and rotatably connected to one end of a connecting rod 16. The other end of the connecting rod 16 is rotatably connected to one end of a double-arm crank 15. In the double-arm crank 15, the central portion is rotatably connected to the boom 11, and the other end is rotatably connected to one end of a bucket cylinder 14. The other end of the bucket cylinder 14 is rotatably connected to the vehicle body 2. The bucket 12 operates by power generated by the bucket cylinder 14. The bucket cylinder 14 is an actuator that generates power to move the bucket 12. When the operator operates a specified working lever, the bucket cylinder 14 extends or retracts. This causes the bucket 12 to swing. The bucket cylinder 14 is, for example, a hydraulic cylinder. The shovel tip 12T has a beveled edge, a flat edge, or other shapes and can be interchangeably mounted to the end of the bucket 12.

[0035] It should be noted that, in this embodiment, as Figure 2 As shown, the orientation of the bucket 12 with the tip 12T pointing downwards is called the tipping orientation. The tipping orientation is, for example, an orientation in which the excavated material inside the bucket 12 can be loaded into a transport vehicle. Furthermore, as... Figure 3As shown, the posture of the bucket 12 with the shovel tip 12T facing the road surface RS and the horizontal direction (including the approximate horizontal direction) is called the digging posture (or the driving posture during digging). The digging posture is, for example, the posture when starting to dig for objects such as sand or soil, or the posture when driving towards the object to be dug (or a posture suitable for starting to dig or driving). Additionally, as... Figure 4 As shown, the posture of the bucket 12 with the shovel tip 12T pointing upwards is called the digging posture (tilted posture). The digging posture is, for example, a posture that can hold the excavated object within the bucket 12. The wheel loader 1, for example, puts the bucket 12 in a digging posture (or from the digging posture to a posture where the shovel tip 12T is lower than the road surface RS), and begins to dig the object located in front by traveling in a forward direction. It should be noted that in the wheel loader 1, since the direction of the shovel tip is substantially horizontal to the road surface RS, the digging posture can also be called the horizontal posture.

[0036] [Structure of the Control System]

[0037] Figure 5 This is a block diagram illustrating an example configuration of the control system of the wheel loader 1 according to the implementation method. For example... Figure 5 As shown, the wheel loader 1 includes a power source 201, a PTO (Power Take Off) 202, a hydraulic pump 203, a control valve 200, an operating device 32, an input display unit 34, and a controller 100.

[0038] The power source 201 generates driving force to cause the installed machinery to move. Examples of power sources include internal combustion engines or electric motors.

[0039] PTO202 transmits at least a portion of the driving force of power source 201 to hydraulic pump 203. PTO202 distributes the driving force of power source 201 to travel mechanism 4 and hydraulic pump 203.

[0040] Hydraulic pump 203 is driven by power source 201 and discharges working oil. At least a portion of the working oil discharged from hydraulic pump 203 is supplied to boom cylinder 13 and bucket cylinder 14 respectively via control valve 200. Control valve 200 controls the flow rate and direction of the working oil supplied from hydraulic pump 203 to boom cylinder 13 and bucket cylinder 14 respectively. The working device 10 is operated by the working oil from hydraulic pump 203.

[0041] The operating device 32 is located inside the cab 3. The operating device 32 is operated by the operator. The operator operates the operating device 32 to adjust the travel direction and speed of the wheel loader 1, switch between forward and reverse, and operate the working device 10. The operating device 32 includes, for example, a steering wheel, gear shift lever, accelerator pedal, brake pedal, and a boom operating device 33 for operating the boom 11 of the working device 10. The input display unit 34 consists of a combination of an input device and a display device, such as a touch panel. The operator uses the input display unit 34 to set, for example, stored values ​​for the target position and target posture in the control of the working device 10, as described later.

[0042] Figure 6 This is a configuration diagram showing the boom operating device 33 according to the embodiment. (See diagram below.) Figure 6 As shown, the boom operating device 33 includes an operating lever 33L capable of tilting relative to a neutral position. The boom operating device 33 is, for example, a lever-type signal generating device as described in Patent Document 1, and includes the operating lever 33L, and a holding mechanism for holding the operating lever 33L in a tilting position 33d. The tilting position 33d is, for example, the position where the operating lever 33L reaches the end of its stroke.

[0043] The boom operating device 33 outputs a control signal corresponding to the tilting direction and tilting amount of the operating lever 33L. Furthermore, when the operating lever 33L is held in the tilted position 33d by the holding mechanism, the boom operating device 33 outputs a predetermined operating mode signal indicating this. It should be noted that, in this embodiment, the state in which the operating lever 33L is held in the tilted position 33d is referred to as the tilt holding state.

[0044] When a recovery indication signal is input, the boom operating device 33 returns the operating lever 33L from the tilt-hold state to the neutral state. The recovery indication signal is, for example, a signal indicating that the angle of the boom 11 or the angle of the boom crank 15 (described later) has reached a specified angle, or that the boom cylinder 13 or the bucket cylinder 14 (described later) has reached a specified length.

[0045] It should be noted that the boom operating device 33 may be an operating lever that does not have a holding function for holding the operating lever in the tilt position 33d. When performing an operation to tilt the operating lever to the end of its stroke, it is also possible to perform an operation that holds the operating lever 33L in the tilt position 33d (tilt-hold operation). In this case, if the operator's hand leaves the operating lever, the operating lever returns to the neutral state, but even if the tilt-hold state continues until the position and posture of the working device 10 reach a predetermined state, a predetermined operating mode signal can still be output. Alternatively, the operating device 32 may be equipped with a button or other predetermined operating element corresponding to the boom lowering and holding operation. Pressing this button or other operation may also be configured to perform a tilt-hold operation.

[0046] In addition, the wheel loader 1 has a working device load sensor 71, a boom angle sensor 72, and a bucket angle sensor 73.

[0047] The load sensor 71 detects the load applied to the working device 10. The load sensor 71 is, for example, a load measuring device such as a strain gauge or force sensor disposed on at least a part of the working device 10. The load data detected by the load sensor 71 is output to the controller 100. It should be noted that the load applied to the working device 10 can also be detected using, for example, a hydraulic sensor that detects the pressure of the hydraulic fluid driving the boom cylinder 13 or the hydraulic sensor that detects the pressure of the hydraulic fluid driving the bucket cylinder 14. In this case, the load applied to the working device 10 changes when the excavated material is held in the bucket 12 and when it is not held. By detecting the change in the load applied to the working device 10, the load sensor 71 can detect the presence or absence of excavated material held in the bucket 12.

[0048] The boom angle sensor 72 detects the angle of the boom 11 relative to the vehicle body 2 and outputs the detection data to the controller 100. The boom angle sensor 72 is, for example, an angle sensor disposed at the connection between the vehicle body 2 and the boom 11. It should be noted that the angle of the boom 11 can also be calculated based on the stroke of the boom cylinder 13.

[0049] The bucket angle sensor 73 is a sensor used to detect the angle of the bucket 12. The bucket angle sensor 73 is, for example, an angle sensor disposed at the connection between the boom 11 and the boom crank 15. The bucket angle sensor 73 detects the angle of the boom crank 15 relative to the boom 11 and outputs the detection data to the controller 100. Based on the angle of the boom 11 relative to the vehicle body 2 detected by the boom angle sensor 72 and the angle of the boom crank 15 relative to the boom 11 detected by the bucket angle sensor 73, the angle of the bucket 12 relative to the boom 11 (and the vehicle body 2) can be calculated. It should be noted that the angle of the bucket 12 relative to the boom 11 can also be detected, for example, at the connection between the bucket 12 and the boom 11 using a sensor that detects the angle of the bucket 12 relative to the boom 11. Furthermore, the angles of the boom crank 15 relative to the boom 11 and the angle of the bucket 12 relative to the boom 11 can also be calculated based on the stroke of the boom cylinder 13 and the stroke of the bucket cylinder 14.

[0050] [Controller Structure]

[0051] Figure 7 This is a configuration diagram of the controller 100 of the wheel loader 1 according to the embodiment. The controller 100 is configured, for example, using an FPGA (Field Programmable Gate Array) or a microcomputer, which includes a processor, main storage device, auxiliary storage device, input / output device, etc. The controller 100 is a functional structure composed of hardware or a combination of hardware and software, and includes an operation signal detection unit 101, a boom angle acquisition unit 102, a bucket loading state estimation unit 103, a bucket angle acquisition unit 104, a storage unit 105, a target boom angle determination unit 106, a target bucket angle determination unit 107, a boom cylinder control unit 108, and a bucket cylinder control unit 109. In addition, the target boom angle determination unit 106 and the target bucket angle determination unit 107 constitute a determination unit 110. In addition, the boom cylinder control unit 108 and the bucket cylinder control unit 109 constitute a control unit 111.

[0052] The controller 100 of this embodiment is a device for controlling a working device 10 having a movable support 17 that changes the position and attitude of the bucket 12. Furthermore, the controller 100 includes: a bucket loading state estimation unit 103 (determination unit) that determines whether there is cargo in the bucket 12; and a determination unit 110 that determines a target working device attitude representing the target position and target attitude of the bucket 12 during control, based on the determination result of the presence or absence of cargo. Additionally, the controller 100 includes a control unit 111 that controls the working device 10 in a manner that achieves the target working device attitude.

[0053] It should be noted that, Figure 7This only describes the structure corresponding to the control corresponding to the operation of the boom operating device 33 in the operating unit 32, which is one of the multiple functions of the controller 100. Furthermore, in the example of the controller 100's operation described later, the control corresponding to the operation of the boom operating device 33... Figure 6 The operation of the boom operating device 33 in the forward tilt holding state (keeping the operating lever 33L in the tilt position 33d) will be described (referred to as boom lowering and holding operation).

[0054] For example, when performing a boom lowering and holding operation on the boom operating device 33, the decision unit 110 determines the target working device posture by having the bucket 12 in a scooping posture when there is a load, and determines the target working device posture by having the bucket 12 in a digging posture when there is no load. Figure 8 This represents an example of a decision made by the decision unit 110 regarding the attitude of the target working device. Figure 8 (a) indicates in Figure 1 The example shown illustrates the determination of the target working device posture (target position and target posture) when the boom operating device 33 is performing a boom descent and holding operation under the shown working device posture (where the loading state is indicated by the loading of cargo 20). In this case, the target posture is the scooping posture, and the target position is the boom descent stop position and the position at a height H (e.g., the lowest height of the bucket 12) from the road surface RS. Furthermore, Figure 8 (b) indicates that in Figure 2 The example shown illustrates the determination of the target working device posture (target position and target posture) during a boom descent and holding operation in the working device posture (unloaded state (state without load 20)). In this case, the target posture is the digging posture, and the target position is the boom descent stop position at a height H from the road surface RS (e.g., the lowest height of the bucket 12).

[0055] The control unit 111 controls the working device 10 based on the manual operation of the boom operating device 33, and, in the case of boom lowering and holding operation, controls the working device 10 in a manner that achieves the target working device posture determined by the decision unit 110. In the case of boom lowering and holding operation, the control unit 111, for example, controls the length of the boom cylinder 13 (boom cylinder length) and the length of the bucket cylinder 14 (bucket cylinder length) to achieve the target working device posture. Figure 7 In the example shown, the control unit 111 controls the boom cylinder length by outputting a predetermined control signal (called boom cylinder command) to the control valve 200 in a manner that makes the current working device posture become the target working device posture, and controls the bucket cylinder length by outputting a predetermined control signal (called bucket cylinder command) to the control valve 200.

[0056] The operation signal detection unit 101 receives the operation signal from the boom operating device 33 within the operating device 32, and outputs a signal indicating that the boom lowering and holding operation is being performed when the boom lowering and holding operation is being performed. For example, the operation signal detection unit 101 may continuously output the signal indicating that the boom lowering and holding operation has been performed during the period when the tilting state is held, or it may perform the output at the start or end of the tilting state.

[0057] The boom angle acquisition unit 102 receives data detected by the boom angle sensor 72 and acquires the current boom angle. The boom angle acquisition unit 102 outputs the acquired current boom angle data to the boom cylinder control unit 108. The current boom angle data may, for example, be data representing the current boom cylinder length.

[0058] The bucket loading status estimation unit 103 receives signals from the working device load sensor 71 and the boom angle sensor 72, and estimates the working device load. Furthermore, the bucket loading status estimation unit 103 compares the estimated working device load with a predetermined threshold; if the working device load exceeds the threshold, it is determined that the device is loaded; otherwise, it is determined that the device is unloaded. The bucket loading status estimation unit 103 then outputs the determination result to the target bucket angle determination unit 107.

[0059] The bucket angle acquisition unit 104 receives data detected by the boom angle sensor 72 and the bucket angle sensor 73, and acquires the current bucket angle. The bucket angle acquisition unit 104 outputs the acquired current bucket angle data to the bucket cylinder control unit 109. The current bucket angle data may, for example, be data representing the current bucket cylinder length.

[0060] The storage unit 105 stores various settings and initial values ​​for the target working device's posture (target position and target posture) under both loaded and unloaded conditions, as stored values, using the input display unit 34. The stored value for the target position can be, for example, a numerical value representing the height RS above the road surface (such as the boom descent stop position). Furthermore, the stored value for the target posture can be, for example, an identification symbol representing postures such as digging posture, shoveling posture, or dumping posture, or angle information representing the direction of the shovel tip. It should be noted that the target position can be the same or different under loaded and unloaded conditions.

[0061] When performing a boom lowering and holding operation, the target boom angle determination unit 106 determines the target boom angle value, i.e., the target boom angle, based on the stored value of the target position stored in the storage unit 105, and outputs the determined target boom angle data to the boom cylinder control unit 108. This target boom angle is a target value that is only valid during the boom lowering and holding operation. It should be noted that, in the following operating example, when performing a boom lowering and holding operation, the target boom angle determination unit 106 determines the target boom angle based on the boom lowering stop position stored in the storage unit 105, regardless of whether there is a load. The target boom angle data may, for example, be a target value representing the boom cylinder length, i.e., data representing the target boom cylinder length.

[0062] When performing a boom lowering and holding operation, the target bucket angle determination unit 107 determines the target bucket angle value, i.e., the target bucket angle, based on the result of determining whether there is a load, the stored values ​​of the target position and target attitude stored in the storage unit 105, and the target boom angle data determined by the target boom angle determination unit 106, and outputs the determined target bucket angle data to the bucket cylinder control unit 109. This target bucket angle is a target value that is only valid during the boom lowering and holding operation. The target bucket angle data may, for example, be a target value representing the bucket cylinder length, i.e., data representing the target bucket cylinder length.

[0063] When the boom cylinder control unit 108 is not performing a boom lowering and holding operation on the boom operating device 33, it calculates the boom cylinder flow rate corresponding to the operation of the manually operated boom operating device 33 and outputs a boom cylinder command with the flow rate in the control valve 200 as the target boom cylinder flow rate. Conversely, when the boom operating device 33 is performing a boom lowering and holding operation, the boom cylinder control unit 108 calculates the target boom cylinder flow rate based on the deviation between the current boom angle obtained by the boom angle acquisition unit 102 and the target boom angle determined by the target boom angle determination unit 106, and outputs a boom cylinder command based on the target boom cylinder flow rate.

[0064] When the boom operating device 33 is performing a boom lowering and holding operation, the bucket cylinder control unit 109 calculates the target bucket cylinder flow rate based on the deviation between the current bucket angle obtained by the bucket angle acquisition unit 104 and the target bucket angle determined by the target bucket angle determination unit 107, and outputs a bucket cylinder command based on the target bucket cylinder flow rate.

[0065] [Example of controller actions]

[0066] Figure 9 This is a flowchart illustrating an example of the operation of the controller 100 in an implementation method. Figure 9 The process shown is repeated at a predetermined cycle. In step S1, the controller 100 obtains the current boom angle based on the signal from the boom angle sensor 72.

[0067] In step S12, the controller 100 obtains the current bucket angle based on the signal from the boom angle sensor 72 and the signal from the bucket angle sensor 73.

[0068] In step S13, the controller 100 determines whether a boom lowering and holding operation of the boom operating device 33 has been performed. The controller 100 determines whether a boom lowering and holding operation has been performed based on a signal indicating that such an operation has been performed. If the controller 100 determines that a boom lowering and holding operation has not been performed (if "No" in step S13), in step S14, it outputs a boom cylinder command corresponding to the current operating amount of the boom operating device 33 to the control valve 200. If the controller 100 determines that a boom lowering and holding operation of the boom operating device 33 has been performed (if "Yes" in step S13), it proceeds to step S16.

[0069] In step S16, the controller 100 determines the target boom stop position based on the stored value.

[0070] In step S17, the controller 100 determines whether the bucket 12 is loaded. The controller 100 determines the loading status of the bucket 12 based on signals from the working device load sensor 71 and the boom angle sensor 72. If the bucket 12 is determined not to be loaded (in the case of "No" in step S17), in step S18, the controller 100 determines the target bucket stop position A based on the stored value (target posture in the case of no loading) and the target boom stop position determined in step S16. Here, the target bucket stop position A corresponds to the target value of the stop position of the bucket 12 (e.g., the stop position of the shovel tip 12T) in the case of no loading 20 (in the shoveling posture).

[0071] On the other hand, when it is determined that the bucket 12 is in a loaded state (if "yes" is set in step S17), in step S19, the controller 100 determines the target bucket stop position B based on the stored value (target posture when loaded) and the target boom stop position determined in step S16. Here, the target bucket stop position B corresponds to the target value of the stop position of the bucket 12 (e.g., the stop position of the tip 12T) when loaded with cargo 20 (in the digging posture).

[0072] In step S20, the controller 100 outputs a boom cylinder command based on the current boom angle and the target boom angle corresponding to the target boom stop position determined in step S16. Additionally, the controller 100 outputs a bucket cylinder command based on the current bucket angle and the target bucket angle corresponding to the target bucket stop position (A or B) determined in steps S18 and S19, respectively.

[0073] In step S21, the controller 100 determines whether the bucket position and boom position have reached their respective target stop positions. If at least one of the bucket position and boom position has not reached a target stop position (if "No" is true in step S21), the determination in step S21 is repeated. On the other hand, if both the bucket position and boom position have reached their respective target stop positions (if "Yes" is true in step S21), the controller 100 terminates. Figure 9 The processing shown.

[0074] Through the above processing, when the boom operating device 33 is performing a boom lowering and holding operation, the controller 100 can determine whether there is a load in the bucket 12 and appropriately determine the target working device posture based on the determination result. Furthermore, the controller 100 can coordinate the control of the boom cylinder 13 and the bucket cylinder 14 to make the posture of the working device 10 the target working device posture. Here, coordinated control refers to the control that automatically moves the bucket at an angle corresponding to the presence or absence of a load while moving the boom.

[0075] [The role and effects of the implementation method]

[0076] According to this embodiment, when the attitude of the bucket 12 is automatically controlled, the target attitude of the bucket 12 can be appropriately determined.

[0077] It should be noted that, as the background of this embodiment, loading machinery (operating vehicles) has multiple levers for operating the boom, bucket, etc., which constitute the working device. Therefore, the complex operation of the working device by multiple levers becomes a burden on the driver. As a countermeasure, for example, as described in Patent Document 1, a holding mechanism is installed on the operating lever to maintain it in a tilted position, which has the function of automatically operating the working device to a fixed position (locking). However, in this background technology, since it is impossible to determine the working conditions based on the presence or absence of cargo in the bucket, automatic operation can only be performed on, for example, on either the frequently occurring and stable working device posture "digging posture (driving posture during digging)" or "posture taken after digging gravel, sand, etc. (bucket scooping posture)". Therefore, in this embodiment, the working device is controlled in a way that determines the working conditions to be transferred next based on the presence or absence of cargo in the bucket, so as to achieve a stable working device posture that meets the working conditions. In this embodiment, the presence or absence of cargo in the bucket is determined, and the attitude of the target working device is determined based on the determination result, so as to coordinate and control the boom and the bucket.

[0078] In addition, this embodiment has the following features. (1) The controller 100 of this embodiment is a device for controlling the working device 10 of the bucket 12 and the movable support 17 for changing the position and posture of the bucket 12. It includes: a bucket loading state estimation unit (determination unit) 103, which determines whether there is a load in the bucket 12; and a determination unit 110, which determines the target working device posture of the bucket 12 based on the determination result of whether there is a load. (2) In addition, the controller 100 also includes a control unit 111 that controls the working device 10 in a manner that becomes the target working device posture. (3) In addition, when there is a load 20, the determination unit 110 determines the target working device posture in a manner that the bucket 12 is in a scooping posture, and when there is no load 20, the determination unit 110 determines the target working device posture in a manner that the bucket is in a digging posture. (4) In addition, when the specified operation is performed on the specified operating part (boom operating device 33, button, etc.) used to operate the movable support part 17, the determination unit 110 determines the posture of the target working device. (5) In addition, the operating part of (4) is an operating lever with a tilting state holding function, and the specified operation can be set to an operation that keeps the operating lever in a tilting state.

[0079] Furthermore, the method (control method) of this embodiment is a method for controlling a working device 10 having a bucket 12 and a movable support 17 that changes the position and posture of the bucket 12. It includes a step of determining whether there is a load in the bucket 12 (step S17), and a step of determining the posture of the target working device representing the target position and target posture of the bucket based on the determination result of whether there is a load (steps S18 to S20).

[0080] [Modifications of this embodiment or other embodiments]

[0081] The embodiments of the invention have been described above with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and also includes design changes that do not depart from the spirit of the invention.

[0082] For example, the wheel loader 1 can also be operated remotely. In this case, part or all of the controller 100 and the operating device 32 can be located, for example, at the location where remote operation is performed.

[0083] Furthermore, the loading machinery (or work vehicle) is not limited to wheel loaders; it can also be other loading machinery such as hydraulic excavators equipped with work tools and movable supports for those work tools. For example, when the loading machinery is a hydraulic excavator, for instance, during loading operations such as sand or soil, when changing the position of the bucket, the bucket's posture is changed to a shoveling posture while the bucket is loaded, and to a digging posture while the bucket is unloaded, and the bucket's posture is changed to a digging posture while the bucket is unloaded, thus coordinating the control of the bucket, stick, and boom.

[0084] Furthermore, the movable support is not limited to changing the position and orientation of the bucket 12; it can also change the orientation of the bucket 12. In this case, the target working device orientation represents the target orientation, and the determination unit 110 can determine the target working device orientation representing the target orientation. Additionally, the working tool is not limited to the bucket. The working device can also be, for example, a fork or grab bucket that can be replaced and mounted as an accessory on a wheel loader.

[0085] In addition, in the above embodiments, part or all of the program executed by the computer can be distributed via a computer-readable recording medium or communication line.

[0086] Industrial availability

[0087] According to various embodiments of the present invention, when the posture of the working tool is automatically controlled, the target posture of the working tool can be appropriately determined.

[0088] Explanation of reference numerals in the attached figures:

[0089] 1 Wheel loader (loading machinery), 2 Body, 3 Cab, 4 Running gear, 5 Wheels, 6 Tires, 10 Working device, 11 Boom, 12 Bucket (working tool), 12T Shovel tip, 13 Boom cylinder, 14 Bucket cylinder, 15 Double boom crank, 16 Connecting rod, 17 Movable support, 100 Controller, 103 Bucket loading status estimation unit (discrimination unit), 110 Decision unit, 111 Control unit.

Claims

1. A control system for a loading machine, comprising a working device including a working tool and a movable support for changing the posture of said working tool, wherein, The control system of the loading machine includes a controller. The controller determines whether the working tool is loaded or not. When the working tool is loaded, it receives an operation to lower the working tool and determines the target working device posture, which represents the target posture of the working tool, as the posture of scooping up the load. Or, when the working tool is unloaded, it receives an operation to lower the working tool and determines the target working device posture, which represents the target posture of the working tool, as the digging posture for digging with the working tool.

2. The control system for the loading mechanism according to claim 1, wherein, The movable support also allows for changes in the position of the working tool. The target working device posture refers to the target posture and target position of the working tool.

3. The control system for the loading mechanism according to claim 1 or 2, wherein, The controller outputs commands to control the movable support in a manner that achieves the orientation of the target working device.

4. The control system for the loading mechanism according to claim 1, wherein, The tool used is a shovel. The controller determines whether the cargo is present or not in the bucket.

5. The control system for the loading mechanism according to claim 1, wherein, The control system of the loading mechanism includes an operating unit for operating the movable support. The controller determines the posture of the target working device when the operating unit performs a prescribed operation.

6. The control system for the loading mechanism according to claim 5, wherein, The operating part is an operating lever with a tilting state holding function. The specified operation is to keep the control lever in a tilted state.

7. A method, executed by a controller, for controlling a loading machine having a working device including a working tool and a movable support for changing the posture of said working tool. The method includes the following steps: Determine whether the work tool is loaded with cargo; and When the working tool is loaded and an operation to lower the working tool is received, the target working device posture representing the target posture of the working tool is determined to be the posture of scooping up the load; or when the working tool is unloaded and an operation to lower the working tool is received, the target working device posture representing the target posture of the working tool is determined to be the digging posture for digging with the working tool.

8. The method according to claim 7, wherein, The movable support also allows for changes in the position of the working tool. The target working device posture refers to the target posture and target position of the working tool.

9. The method according to claim 7 or 8, wherein, The method further includes the following step: outputting a command to control the movable support in a manner that achieves the posture of the target working device.

10. An loading mechanism, wherein, The loading mechanism includes: A working device having a working tool and a movable support for changing the posture of the working tool; An operating unit is used to operate the movable support unit; as well as Controller The controller determines whether the working tool is loaded or not. When the working tool is loaded, it receives an operation to lower the working tool and determines the target working device posture, which represents the target posture of the working tool, as the posture of scooping up the load. Or, when the working tool is unloaded, it receives an operation to lower the working tool and determines the target working device posture, which represents the target posture of the working tool, as the digging posture for digging with the working tool. The controller then outputs a control command for the movable support in such a way as the target working device posture.

11. The loading mechanism according to claim 10, wherein, The movable support also allows for changes in the position of the working tool. The target working device posture refers to the target posture and target position of the working tool.

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