Loader bottom fork accessory lifting control method, device and equipment and medium

Abstract

The invention discloses a loading machine bottom fork accessory lifting control method, device and equipment and a medium. The target bottom fork angle of a loading machine bottom fork accessory and the movable arm joint angle and the rocker arm joint angle of a loading machine are obtained; the actual length of a movable arm oil cylinder and the actual length of a rocker arm oil cylinder are calculated according to the movable arm joint angle and the rocker arm joint angle; determining the target length of a movable arm oil cylinder and the target length of a rocker arm oil cylinder according to the target bottom fork angle; a first deviation value between the target length of the movable arm oil cylinder and the actual length of the movable arm oil cylinder and a second deviation value between the target length of the rocker arm oil cylinder and the actual length of the rocker arm oil cylinder are calculated; and controlling a movable arm oil cylinder and a rocker arm oil cylinder of the loading machine according to the first deviation value and the second deviation value by adopting double-ring series control logic, so that the bottom fork accessory is lifted in parallel. The double-loop series control logic is adopted, and the posture keeping precision of the bottom fork accessory in the lifting process is improved.

Description

Technical Field

[0001] This invention relates to the field of loader control technology, specifically to a loader horizontal fork attachment lifting control method, device, equipment, and medium. Background Technology

[0002] Loaders are a type of earthmoving and transport machinery widely used in highways, railways, ports, docks, coal mines, water conservancy projects, national defense projects, and urban construction. During the lifting process, if the fork attachments cannot maintain a stable posture and experience changes in tilt angle, the cargo may slip, be damaged, or even cause a safety accident. Therefore, achieving parallel control of the fork attachments throughout the lifting process is crucial for improving operational safety, efficiency, and operator comfort.

[0003] In related technologies, the control methods for loader swingarm attachments are mainly divided into three categories. One is traditional pure hydraulic manual control, where the operator, based on experience, simultaneously manipulates the boom and bucket control levers to maintain the attachment's posture. This method demands extremely high operator skill, is labor-intensive, and struggles to guarantee control accuracy and consistency. Another method involves modifying the mechanical structure of the loader's swingarm lifting mechanism, setting it to a parallelogram-shaped linkage structure. However, modifying the mechanical structure is complex, and since loaders are used with multiple working devices, modified structures often struggle to adapt to other devices. A third method uses angle sensors to measure the angles of the boom and swingarm, then calculates the target angle value in real time and directly controls the boom and swingarm rotation based on the angle deviation. However, this method can result in vibration or control lag during lifting. Regardless of manual control, mechanical structure modification, or adjustment method, it is difficult to guarantee that the real-time tilt angle during parallel lifting matches the pre-adjusted tilt angle. Summary of the Invention

[0004] This invention provides a lifting control method, device, equipment, and medium for loader horizontal fork attachments to solve the problem that the tilt angle cannot be kept consistent with the target tilt angle when the loader horizontal fork attachments are lifted in parallel.

[0005] In a first aspect, the present invention provides a lifting control method for a loader's horizontal fork attachment, the method comprising: Obtain the target fork angle of the loader's swingarm attachment, the boom joint angle of the loader, and the rocker arm joint angle; Based on the geometric kinematic relationship, the actual lengths of the boom cylinder and rocker arm cylinder are calculated according to the boom joint angle and the rocker arm joint angle. Based on the target fork angle, determine the target length of the boom cylinder and the target length of the rocker arm cylinder; Calculate the first deviation value between the target length of the boom cylinder and the actual length of the boom cylinder, and the second deviation value between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder; A dual-loop series control logic is adopted to control the boom cylinder and rocker arm cylinder of the loader according to the first deviation value and the second deviation value, so that the horizontal fork attachment is lifted in parallel; wherein, the dual-loop series control logic includes position loop control logic and speed loop control logic.

[0006] This invention calculates the difference between the target length and the actual length of the boom cylinder and rocker arm cylinder in real time, and adopts a position and speed dual-loop series control logic to improve the attitude maintenance accuracy of the flat fork attachment during the lifting process and reduce the operator's operating burden.

[0007] In one optional implementation, before calculating the actual lengths of the boom cylinder and rocker arm cylinder, the following steps are included: Establish a coordinate system with the hinge point between the boom and the frame as the origin; Obtain the first coordinate of the hinge point between the tail of the boom cylinder and the frame in the coordinate system, and the second coordinate of the hinge point between the tail of the rocker arm cylinder and the frame in the coordinate system.

[0008] This invention selects the hinge point between the boom and the frame as the origin of the coordinate system. This point remains stationary relative to the frame during the lifting process of the working device. Using this as the origin of the coordinate system simplifies the derivation process of the geometric relationship between the boom joint angle and the rocker arm joint angle, reduces the complexity of the controller's real-time calculation, and provides a unified benchmark for subsequent accurate calculation of the actual length and target length of the boom cylinder and rocker arm cylinder.

[0009] In one optional implementation, calculating the actual length of the boom cylinder and the rocker arm cylinder includes: Calculate the boom rotation angle based on the boom joint angle and the structural constant angle of the boom; Based on the boom rotation angle, calculate the fourth coordinate of the boom cylinder piston rod head in the coordinate system; The Euclidean distance between the fourth coordinate and the first coordinate is calculated to obtain the actual length of the boom cylinder.

[0010] This invention directly calculates the piston rod head coordinates based on the boom rotation angle and solves for the actual length of the boom cylinder using the Euclidean distance formula. It simplifies the geometric relationship into a concrete calculation, improves the real-time performance of the cylinder length calculation, and provides accurate data support for the rapid response of the position loop and speed loop in parallel lifting control.

[0011] In one optional implementation, calculating the actual length of the boom cylinder and the rocker arm cylinder further includes: Based on the boom rotation angle, calculate the coordinates of the boom-rocker hinge point, which is the hinge point between the boom and the rocker arm of the loader. Based on the measured rocker arm joint angle and the known structural angle of the boom rocker arm, calculate the first included angle formed by the three points: the boom rocker arm hinge point, the rocker arm connecting rod hinge point, and the boom bucket hinge point. The vertex of the first included angle is the boom rocker arm hinge point. Based on the first included angle, the length of the rocker arm structure, and the first hinge distance, the length of the first virtual side between the boom bucket hinge point and the rocker arm connecting rod hinge point is calculated using the cosine theorem, wherein the first hinge distance is the distance between the boom rocker arm hinge point and the boom bucket hinge point. The bucket attitude angle is determined based on the length of the first virtual opposite side; Based on the bucket posture angle, the known angle of the bucket structure, the first hinge distance, and the length of the connecting rod structure, the length of the second virtual side between the boom rocker arm hinge point and the connecting rod bucket hinge point is calculated using the law of cosines. Based on the length of the second virtual opposite side, calculate the rotation angle of the rocker arm cylinder piston rod head and the rocker arm hinge point relative to the horizontal line; Based on the rotation angle and the coordinates of the rocker arm hinge point, determine the coordinates of the rocker arm cylinder piston rod head hinge point; The Euclidean distance between the hinge point coordinates of the piston rod head of the rocker arm cylinder and the second coordinate is calculated to obtain the actual length of the rocker arm cylinder.

[0012] This invention calculates the coordinates of the hinge point of the rocker arm cylinder piston head through the above-mentioned multiple steps, and obtains the actual length of the rocker arm cylinder using Euclidean distance. This enables the accurate calculation of the actual length of the rocker arm cylinder based on the angle sensor and structural constant parameters without the need for additional sensors.

[0013] In one optional implementation, the position loop employs proportional control, and the speed loop control logic employs at least one of model predictive control, proportional-integral control, and active disturbance rejection control.

[0014] This invention employs a dual-loop structure consisting of a position loop and a speed loop connected in series. The position loop is responsible for target position tracking, while the speed loop is responsible for disturbance suppression and speed response. This not only ensures the steady-state accuracy of the tilt angle control of the horizontal fork attachment during parallel lifting, but also improves the coordinated action performance of the boom and rocker arm cylinders.

[0015] In one alternative implementation, the method further includes: When the boom speed of the loader is in the first gear, the boom cylinder is controlled to extend and retract using the first control mode. When the boom speed of the loader is in the second gear, the boom cylinder is controlled to extend and retract using the second control mode. When the loader's boom speed is in the third gear, the boom cylinder is controlled to extend and retract using the third control mode.

[0016] The three-layer control mode of this invention automatically switches according to the boom speed, which improves work efficiency while ensuring the control capability of the parallel lifting function.

[0017] In one optional implementation, obtaining the boom joint angle and rocker arm joint angle of the loader includes: The boom joint angle and rocker arm joint angle of the loader are obtained by an angle sensor installed at the hinge between the boom and rocker arm, or by an IMU inertial measurement unit.

[0018] Secondly, the present invention provides a lifting control device for a loader horizontal fork attachment, the device comprising: The information acquisition module is used to acquire the target fork angle of the loader's fork attachment, the boom joint angle of the loader, and the rocker arm joint angle. The actual length calculation module is used to calculate the actual length of the boom cylinder and the actual length of the rocker arm cylinder based on the geometric kinematic relationship and according to the boom joint angle and the rocker arm joint angle. The target length determination module is used to determine the target length of the boom cylinder and the target length of the rocker arm cylinder based on the target fork angle. The difference calculation module is used to calculate the first deviation value between the target length of the boom cylinder and the actual length of the boom cylinder, and the second deviation value between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder. The control module is used to control the boom cylinder and rocker arm cylinder of the loader according to the first deviation value and the second deviation value, so that the flat fork attachment is lifted in parallel; wherein, the dual-loop series control logic includes position loop control logic and speed loop control logic.

[0019] Thirdly, the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform a loader fork attachment lifting control method according to the first aspect or any corresponding embodiment described above.

[0020] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute a loader fork attachment lifting control method according to the first aspect or any corresponding embodiment described above.

[0021] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute a loader fork attachment lifting control method according to the first aspect or any corresponding embodiment described above. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of an application scenario according to an embodiment of the present invention; Figure 2 This is a diagram showing the connection relationship of each hinge point of the loader according to an embodiment of the present invention, as well as the actual structural diagram of the loader. Figure 3 This is a simplified structural diagram of the loader according to an embodiment of the present invention, showing the connection relationship of each hinge point. Figure 4 This is a flowchart illustrating a lifting control method for a loader horizontal fork attachment according to an embodiment of the present invention; Figure 5 This is another schematic flowchart of a loader fork attachment lifting control method according to an embodiment of the present invention; Figure 6 This is a control principle diagram of a loader fork attachment lifting control method according to an embodiment of the present invention; Figure 7 This is a rocker arm control logic diagram of a loader fork attachment lifting control method according to an embodiment of the present invention; Figure 8 This is a structural block diagram of a loader fork attachment lifting control device according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] like Figure 1 The diagram shown is a structural schematic of a loader provided in an embodiment of the present invention. Figure 1 As shown, A is the hinge point between the boom and the frame; B is the hinge point between the tail of the rocker arm cylinder and the frame; C is the hinge point between the head of the rocker arm cylinder piston rod and the rocker arm; D is the hinge point between the rocker arm and the boom; E is the hinge point between the rocker arm and the connecting rod; F is the hinge point between the connecting rod and the bucket; G is the hinge point between the boom and the bucket; K is the hinge point between the tail of the boom cylinder and the frame; Q is the tooth tip; and M is the hinge point between the piston head of the boom cylinder and the boom. The loader includes a frame, boom, boom cylinder that drives the boom to rotate, rocker arm, rocker arm cylinder that drives the rocker arm to rotate, and bucket. The bucket is also called the swingarm device, which is connected to the rocker arm and hinged to the boom at point G. Figure 2 The diagram shows the connection relationship of each hinge point of the loader and the actual structure of the loader, as provided in the embodiments of the present invention. Figure 3 The diagram shown illustrates the connection relationship of various hinge points of the loader provided in this embodiment of the invention, as well as a simplified structural diagram of the loader. Figure 2 and Figure 3 As shown, A1 is located 0.5m directly below point A, meaning AA1 is a vertical line pointing downwards. Figure 3 In the simplified structural diagram, Q is located on the same horizontal line as point G, 1m to the right of point G.

[0028] According to an embodiment of the present invention, a lifting control method for a loader fork attachment is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0029] This embodiment provides a lifting control method for a loader's horizontal fork attachment, which can be used with the aforementioned loader or with a terminal for controlling the loader, including a mobile phone, tablet computer, or computer. Figure 4This is a flowchart of a loader fork attachment lifting control method according to an embodiment of the present invention, such as... Figure 4 As shown, the process includes the following steps: Step S401: Obtain the target horizontal fork angle of the loader's horizontal fork attachment, the boom joint angle of the loader, and the rocker arm joint angle.

[0030] The horizontal fork attachment refers to the working tool installed at the front of the loader's working device, used for lifting and moving goods, and its posture must remain stable during lifting. The target horizontal fork angle refers to the desired angle between the working plane of the horizontal fork attachment and the horizontal plane, used to achieve the control target of parallel lifting. The boom joint angle refers to the angle formed at the hinge point between the boom and the frame, reflecting the rotational position of the boom relative to the frame. The rocker arm joint angle refers to the angle formed at the hinge point between the rocker arm and the boom, reflecting the rotational position of the rocker arm relative to the boom.

[0031] This step is the initial step in the loader swingarm attachment lifting control method, used to collect three key angle information required during the control process. Among them, the target swingarm angle is the angle between the swingarm attachment's working plane and the horizontal plane, which is preset according to specific operational requirements and serves as the target value for control.

[0032] Step S402: Based on the geometric kinematic relationship, calculate the actual length of the boom cylinder and the actual length of the rocker arm cylinder according to the boom joint angle and the rocker arm joint angle.

[0033] Geometric kinematics is a mathematical relationship established using the geometric constraints and motion transmission laws between the hinge points in the working device. It describes the corresponding changes between the position and posture of the components. The boom cylinder is a hydraulic actuator that drives the boom to rise and fall, changing the boom's working position through the extension and retraction of the piston rod. The rocker arm cylinder is a hydraulic actuator that drives the rocker arm to rotate, changing the rocker arm's working posture through the extension and retraction of the piston rod.

[0034] This embodiment is based on geometric kinematics. The boom joint angle and rocker arm joint angle obtained by real-time measurement in the aforementioned steps are used as input parameters. The actual length of the boom cylinder and the actual length of the rocker arm cylinder are calculated respectively through the pre-established mathematical relationship.

[0035] Step S403: Determine the target length of the boom cylinder and the target length of the rocker arm cylinder based on the target horizontal fork angle.

[0036] The target length is the theoretical extension length that the boom cylinder or rocker arm cylinder should achieve in order to realize the desired target horizontal fork angle.

[0037] In this embodiment of the invention, the target horizontal fork angle is used as an input parameter. Through pre-established mathematical relationships, the target lengths that the boom cylinder and rocker arm cylinder should reach to achieve the target horizontal fork angle are calculated. This calculation process, based on the geometric kinematic relationships between the components of the loader's working device, transforms the control requirements of the horizontal fork device into control targets for the extension and retraction lengths of the two hydraulic cylinders.

[0038] Step S404: Calculate the first deviation between the target length of the boom cylinder and the actual length of the boom cylinder, and the second deviation between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder.

[0039] The first deviation value is the difference between the target length and the actual length of the boom cylinder, reflecting the current position error of the boom cylinder. The second deviation value is the difference between the target length and the actual length of the rocker arm cylinder, reflecting the current position error of the rocker arm cylinder.

[0040] In this embodiment, the first deviation value is calculated by subtracting the target length of the boom cylinder calculated in step S403 from the actual length of the boom cylinder calculated in step S402, and the second deviation value is calculated by subtracting the target length of the rocker arm cylinder from the actual length of the rocker arm cylinder. These two deviation values ​​reflect the error between the current actual position and the desired position of the boom cylinder and the rocker arm cylinder, respectively, providing error input for subsequent control steps.

[0041] Step S405: A dual-loop series control logic is adopted to control the boom cylinder and rocker arm cylinder of the loader according to the first deviation value and the second deviation value, so that the horizontal fork attachment is lifted in parallel; wherein, the dual-loop series control logic includes position loop control logic and speed loop control logic.

[0042] The dual-loop series control logic refers to a control structure consisting of two control loops connected in series. In this invention, the outer loop is a position loop, and the inner loop is a speed loop. The position loop control logic takes the position deviation as input and calculates the desired speed command through a control algorithm. The output of the position loop serves as the input of the speed loop, and the speed loop control logic uses the deviation between the desired speed and the actual speed as the calculation basis to calculate the control current through a control algorithm.

[0043] In this embodiment of the invention, a dual-loop series control logic is employed. The first and second deviation values ​​obtained in step S403 are used as inputs to the position loop. The position loop calculates the desired speed command using a proportional control method. The speed loop calculates the control current based on the deviation between the speed command and the actual speed. This control current drives the boom cylinder and rocker arm cylinder to extend and retract, ensuring that the horizontal fork attachment maintains a set horizontal fork angle during lifting, thus achieving parallel lifting. In the dual-loop series control logic, the position loop ensures the positional accuracy of the cylinder extension and retraction, while the speed loop ensures the speed and smoothness of the cylinder movement.

[0044] This embodiment provides a lifting control method for a loader's swingarm attachment. It calculates the difference between the target length and the actual length of the boom cylinder and rocker arm cylinder in real time, and adopts a position and speed dual-loop series control logic to improve the attitude maintenance accuracy of the swingarm attachment during the lifting process and reduce the operator's operating burden.

[0045] This embodiment provides another method for controlling the lifting of a loader's horizontal fork attachment, which can be used with the aforementioned loader or with a terminal for controlling the loader, including a mobile phone, tablet computer, or computer. Figure 5 This is a flowchart of a loader fork attachment lifting control method according to an embodiment of the present invention, such as... Figure 5 As shown, the process includes the following steps: Step S501: Obtain the target horizontal fork angle of the loader's horizontal fork attachment, the boom joint angle of the loader, and the rocker arm joint angle.

[0046] Specifically, step S501 includes: S5011: The boom joint angle and rocker arm joint angle of the loader are obtained by an angle sensor installed at the hinge between the boom and rocker arm of the loader, or by an IMU inertial measurement unit.

[0047] An angle sensor refers to an electronic component installed at a mechanical hinge point, used to directly measure and output the relative angular displacement between two parts. An IMU (Inertial Measurement Unit) is a sensor module that includes a gyroscope and an accelerometer, which calculates the attitude angle of an object by measuring linear acceleration and angular velocity.

[0048] This embodiment obtains the boom joint angle and rocker arm joint angle in two ways: First, high-precision angle sensors installed at the hinge between the boom and rocker arm collect joint rotation data in real time; second, IMU inertial measurement units arranged on the boom and rocker arm are used to indirectly calculate the joint angle information through inertial navigation algorithms. The target fork angle is set by the operator or generated by the loader's automatic control system according to the loader's specific operating mode.

[0049] In one specific embodiment, a first angle sensor is installed at the hinge point between the boom and the frame, and a second angle sensor is installed at the hinge point between the rocker arm and the boom. Alternatively, an IMU (Inertial Measurement Unit) can be fixedly installed in the middle of the boom and on the rocker arm as another angle measurement method. An angle sensor and an IMU can also be used simultaneously as redundant measurement methods. The controller receives the set target fork angle command via a CAN bus (Controller Area Network). During operation, the sensor components collect analog signals of the boom joint angle and rocker arm joint angle in real time, convert them, and input them to the controller.

[0050] This embodiment achieves high-precision real-time monitoring of the attitude of the loading boom and rocker arm by arranging angle sensors at key hinge points or using an IMU inertial measurement unit, providing a reliable data foundation for the automatic leveling and angle control of the fork attachment.

[0051] Step S502: Based on the geometric kinematic relationship, calculate the target length of the boom cylinder and the target length of the rocker arm cylinder according to the target horizontal fork angle, boom joint angle and rocker arm joint angle.

[0052] Specifically, the steps preceding step S502 include: Step b1: Establish a coordinate system with the hinge point between the boom and the frame as the origin; Step b2: Obtain the first coordinate of the hinge point between the tail of the boom cylinder and the frame in the coordinate system, and the second coordinate of the hinge point between the tail of the rocker arm cylinder and the frame in the coordinate system.

[0053] The coordinate system refers to a planar rectangular reference frame established with the hinge point between the boom and the frame as the origin, used to calculate the spatial coordinates of each hinge point; the first coordinate set refers to the position data of each key hinge point on the boom in the coordinate system; the second coordinate set refers to the position data of each key hinge point on the rocker arm in the coordinate system; and the third coordinate set refers to the position data of each key hinge point on the bucket or fork attachment in the coordinate system.

[0054] In the specific implementation process, the first step is to establish a system based on... Figure 2A two-dimensional plane coordinate system is established with the hinge point A between the boom and the frame as the origin. The positive directions of the X and Y axes are determined with the origin as the reference. Since the hinge points between the tail of the boom cylinder and the frame, as well as the hinge points between the tail of the rocker arm cylinder and the frame, are fixed, after establishing the coordinate system with A as the origin, the first coordinate of the hinge point between the tail of the boom cylinder and the frame, and the second coordinate of the hinge point between the tail of the rocker arm cylinder and the frame, can be obtained in the coordinate system.

[0055] Specifically, step S502 above, "calculating the actual length of the boom cylinder and the rocker arm cylinder," includes: Step S502-01: Calculate the boom rotation angle based on the boom joint angle and the structural constant angle of the boom. Step S502-02: Based on the boom rotation angle, calculate the fourth coordinate of the boom cylinder piston rod head in the coordinate system; Step S502-03: Calculate the Euclidean distance between the fourth coordinate and the first coordinate to obtain the actual length of the boom cylinder.

[0056] Where ∠A1AD is the boom joint angle measured by the angle sensor and IMU inertial measurement unit, ∠ADE is the rocker arm joint angle measured by the angle sensor and IMU inertial measurement unit, and ∠DAG is the structural constant angle of the boom, which can be a known structural constant angle or a known angle measured by the aforementioned angle sensor and IMU inertial measurement unit. The boom rotation angle is then obtained by the following formula:

[0057] Based on the boom rotation angle θ1 calculated in S502-01, the fourth coordinate of the boom cylinder piston rod head M in the coordinate system is further calculated using the following formula:

[0058] In the formula, M is the value of the fourth coordinate of the boom cylinder piston rod head in the coordinate system; A is the coordinate of the origin of the coordinate system; AM is the length of the boom cylinder piston rod head; θ1 is the boom rotation angle; ∠MAG is the included angle between the boom cylinder piston rod head, the origin, and the hinge point of the boom and the bucket.

[0059] After calculating the coordinates of the boom cylinder piston rod head in the coordinate system, this embodiment calculates the Euclidean distance between this coordinate and the aforementioned first coordinate, which is the actual length of the boom cylinder:

[0060] In the formula, length_boom represents the actual length of the boom cylinder; norm(M-K) represents the Euclidean distance between the fourth coordinate and the first coordinate.

[0061] Assume the coordinates of point M are (x... M ,y M The coordinates of point K are (x...). K ,y K The Euclidean distance is calculated as follows:

[0062] In the formula, norm(M-K) is the Euclidean distance between the fourth coordinate and the first coordinate; M is the value of the fourth coordinate of the boom cylinder piston rod head in the coordinate system; K is the value of the first coordinate; (x M ,y M (x) represents the coordinates of point M; K ,y K Let K be the coordinates of point K.

[0063] Specifically, step S302 above, "calculating the actual length of the boom cylinder and the rocker arm cylinder," also includes: Step S502-11: Calculate the coordinates of the boom-rocker hinge point based on the boom rotation angle. The boom-rocker hinge point is the hinge point between the boom and rocker arm of the loader.

[0064] Based on the boom rotation angle calculated in the aforementioned steps, the coordinates of the boom rocker arm hinge point can also be calculated. In a specific implementation of this invention, the formula for calculating the coordinates of the boom rocker arm hinge point D is as follows:

[0065] In the formula, AD is the known length between the boom and frame hinge point A and the rocker arm and boom hinge point D; D is the coordinate of the boom and rocker arm hinge point; D is the coordinate of the frame hinge point (i.e., the origin of the coordinate system); θ1 is the boom rotation angle; ∠DAG is the included angle between the boom and rocker arm hinge point, the frame hinge point, and the boom and bucket hinge point.

[0066] Step S502-12: Based on the measured rocker arm joint angle and the known structural angle of the boom rocker arm, calculate the first included angle formed by the three points: the boom rocker arm hinge point, the rocker arm connecting rod hinge point, and the boom bucket hinge point. The vertex of the first included angle is the boom rocker arm hinge point. Wherein, the first included angle is Figure 2 The first included angle ∠EDG is formed by the three points: the boom rocker arm hinge point D, the rocker arm connecting rod hinge point E, and the boom bucket hinge point G. The vertex of the first included angle ∠EDG is the boom rocker arm hinge point D. ∠EDG = ∠ADG - ∠ADE, where ∠ADE is the rocker arm joint angle, and ∠ADG is the known structural angle of the boom rocker arm. Both the rocker arm joint angle and the known structural angle of the boom rocker arm are known angles obtained by measurement or known fixed angles.

[0067] Step S502-13: Based on the first included angle, the length of the rocker arm structure, and the first hinge distance, calculate the length of the first virtual side between the boom bucket hinge point and the rocker arm connecting rod hinge point using the cosine theorem, where the first hinge distance is the distance between the boom rocker arm hinge point and the boom bucket hinge point.

[0068] Wherein, the length of the first virtual edge is Figure 2 The distance between EG, where E is the rocker arm linkage hinge point and G is the boom bucket hinge point, is specifically calculated in this embodiment according to the following formula:

[0069] In the formula, DE and DG are the known lengths of the loader, which can be found in the official data according to the specific model of the loader, or obtained through actual measurement; EG is the length of the first virtual side.

[0070] Step S502-14: Determine the bucket attitude angle based on the length of the first virtual opposite side.

[0071] After calculating the length EG of the first virtual opposite side according to the aforementioned steps, the attitude angle of the bucket can be determined. Specifically, first calculate the degree measure of ∠FGE according to the following formula:

[0072] Then calculate the degree measure of ∠DGE using the following formula:

[0073] The difference between the two is then calculated, i.e., ∠FGD = ∠FGE - ∠DGE, thus determining the bucket attitude angle θ2:

[0074] Step S502-15: Calculate the length of the second virtual side between the boom rocker arm hinge point and the connecting rod bucket hinge point based on the bucket attitude angle, the known angle of the bucket structure, the first hinge distance, and the length of the connecting rod structure.

[0075] Based on the bucket attitude angle calculated in the previous step, this embodiment uses the following formula to calculate the degree measure of ∠DGF:

[0076] The length of DF, which is the length of the second virtual side, is then calculated using the following formula: (The formula is not provided in the original text.)

[0077] Step S502-16: Based on the length of the second virtual opposite side, calculate the rotation angle of the rocker arm cylinder piston rod head and the rocker arm hinge point relative to the horizontal line.

[0078] In a specific implementation of the present invention, based on the second virtual side length DF obtained from the aforementioned steps, the measures of ∠FDG and ∠FDE are first calculated using the following formula:

[0079] Therefore, ∠EDG = ∠FDE - ∠FDG, and thus we can calculate:

[0080] Therefore, the rotation angle of the piston rod head of the rocker arm cylinder relative to the horizontal line is determined by the following formula:

[0081] In the formula, θ1 is the boom rotation angle.

[0082] Step S502-17: Determine the coordinates of the hinge point of the rocker arm cylinder piston rod head based on the rotation angle and the coordinates of the rocker arm hinge point.

[0083] In a specific implementation of the present invention, based on the rotation angle ∠CDH and the coordinates D of the rocker arm hinge point, the coordinates C of the rocker arm cylinder piston rod head hinge point can be calculated using the following formula:

[0084] In the formula, C is the coordinate of the hinge point of the piston rod head of the rocker arm cylinder; D is the coordinate of the hinge point of the boom rocker arm; and CD is the length between the hinge point of the piston rod head of the rocker arm cylinder and the hinge point of the boom rocker arm.

[0085] Step S502-18: Calculate the Euclidean distance between the hinge point coordinates of the piston rod head of the rocker arm cylinder and the second coordinate to obtain the data length of the rocker arm cylinder.

[0086] After calculating the coordinates of the hinge point C at the piston rod head of the rocker arm cylinder in the coordinate system, this embodiment of the invention calculates the Euclidean distance between this coordinate and the aforementioned second coordinate, which is the actual length of the rocker arm cylinder:

[0087] In the formula, length_bucket is the actual length of the rocker arm cylinder; norm(C-B) is the Euclidean distance between the coordinates of the hinge point of the piston rod head of the rocker arm cylinder and the second coordinate.

[0088] Assume the coordinates of point C are (x... C ,y C The coordinates of point B are (x, y). B ,y B ),but:

[0089] In the formula, norm(C-B) is the Euclidean distance between the coordinates of the hinge point of the rocker arm cylinder piston rod head and the second coordinate; C is the hinge point of the rocker arm cylinder piston rod head; B is the second coordinate; (x C ,y C (x) represents the coordinates of the hinge point at the head of the rocker arm cylinder piston rod; B ,y B ) represents the coordinate value of the second coordinate.

[0090] Step S503: Determine the target length of the boom cylinder and the target length of the rocker arm cylinder based on the target horizontal fork angle; In a coordinate system constructed with the hinge point between the boom and the frame as the origin, the boom joint angle and rocker arm joint angle required to achieve the target horizontal fork angle can be calculated based on the set target horizontal fork angle. Then, the calculation process in step S502 is used to calculate the target length of the boom cylinder and the target length of the rocker arm cylinder. The only difference is that the target length of the cylinder is calculated based on the target horizontal fork angle in step S503. Therefore, the calculation process in step S503 will not be described in detail here.

[0091] Step S504: Calculate the first deviation between the target length of the boom cylinder and the actual length of the boom cylinder, and the second deviation between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder.

[0092] After calculating the actual and target lengths of the boom cylinder and the rocker arm cylinder in the aforementioned steps, the first deviation value and the second deviation value are obtained by subtracting the target length from the actual length of the boom cylinder and the target length from the actual length of the rocker arm cylinder, respectively.

[0093] In one specific embodiment, after the loader activates the parallel lifting function, the operator sets the horizontal tilt angle of the fork attachment to 'a' degrees via the display screen. The controller reads the values ​​from the boom joint angle sensor and the rocker arm joint angle sensor in real time, and calculates the actual lengths of the boom cylinder and rocker arm cylinder in the current posture using trigonometric functions. Simultaneously, it calculates the target lengths of the boom cylinder and rocker arm cylinder based on the set target tilt angle 'a' degrees. For example, based on trigonometric functions, the actual length of the boom cylinder in the current posture is calculated to be 1250 mm and the actual length of the rocker arm cylinder is 680 mm. Simultaneously, based on the set target tilt angle 'a' degrees, the target lengths of the boom cylinder and rocker arm cylinder are calculated to be 1258 mm and 685 mm, respectively. This yields a first deviation value of 8 mm and a second deviation value of 5 mm.

[0094] Step S505: A dual-loop series control logic is adopted to control the boom cylinder and rocker arm cylinder of the loader according to the first deviation value and the second deviation value, so that the horizontal fork attachment is lifted in parallel; wherein, the dual-loop series control logic includes position loop control logic and speed loop control logic.

[0095] The position loop control logic refers to the control loop that generates speed commands based on the deviation between the target position and the actual position of the hydraulic cylinder. The speed loop control logic refers to the control loop that receives speed commands and generates current drive signals. The controller inputs the first deviation value and the second deviation value into the position loop control logic. The position loop outputs the speed setpoint using a preset algorithm. After receiving the speed setpoint, the speed loop uses a model predictive control algorithm to generate current control signals, which drive the boom cylinder electromagnetic proportional valve and the rocker arm cylinder electromagnetic proportional valve to adjust the extension and retraction of the hydraulic cylinders, so that the flat fork attachment always maintains the set tilt angle during the lifting process.

[0096] Continuing the example above, the position loop proportional controller converts the first deviation value of 8 mm into a boom cylinder extension speed command of 8 mm / s, and the second deviation value of 5 mm into a rocker arm cylinder extension speed command of 5 mm / s. The speed loop model predictive controller optimizes the output current value based on the speed command, combined with the actual movement speed of the cylinder and the hydraulic system pressure value. It then drives the boom cylinder solenoid proportional valve and the rocker arm cylinder solenoid proportional valve to control the cylinder movement according to the optimized current value. During the movement of the cylinder according to the speed command, the speed loop corrects the current in real time to suppress load disturbances, so that the actual length of the boom cylinder and the actual length of the rocker arm cylinder synchronously approach the target length. During the lifting process, the actual tilt angle of the fork attachment is always controlled within the range of 0 degrees ± 0.3 degrees.

[0097] In some embodiments of the present invention, the position loop in step 505 adopts proportional control, and the speed loop control logic in step 505 adopts at least one of model predictive control, proportional-integral control, and active disturbance rejection control.

[0098] Among them, proportional control refers to a control method that converts the deviation value into the output quantity according to a fixed proportion; model predictive control refers to a control algorithm that calculates the control quantity through rolling optimization of a predictive model; proportional-integral control refers to a control algorithm that combines proportional and integral actions to eliminate steady-state errors; and active disturbance rejection control refers to a control algorithm that estimates and compensates for internal and external disturbances through an extended state observer. Model predictive control is MPC (Model Predictive Control), proportional-integral control is specifically PI (Proportional-Integral Control), and active disturbance rejection control is ADRC (Active Disturbance Rejection Control).

[0099] In a specific implementation of this invention, the speed loop control logic selects at least one of MPC control, PI control, and ADRC control. When the speed loop uses MPC control, the controller establishes a predictive model of the cylinder speed response, constructs a cost function with the objectives of minimizing speed tracking error and smoothing control increment, solves a constrained quadratic programming problem in each control cycle, and outputs the optimal current control quantity. When the speed loop uses PI control, the controller multiplies the speed deviation value by a proportional coefficient to obtain the proportional control component, integrates the speed deviation value to obtain the integral control component, and adds the two to output the current control quantity. When the speed loop uses ADRC control, the controller estimates the total system disturbance in real time based on the input current and output speed using an extended state observer, subtracts the disturbance estimate after nonlinear combination of the deviation between the speed command and the actual speed, and generates the current control quantity to offset the effects of internal and external disturbances. Figure 6 The diagram shown is a control principle diagram provided in an embodiment of the present invention. The difference between the actual position and the reference position is input to the proportional controller, which serves as the position loop. The speed parameter in the speed command output by the position loop is subtracted from the actual speed, and the speed difference is input to the MPC controller, which serves as the speed loop. The current command output by the MPC controller is input to the electronically controlled proportional valve cylinder, thereby controlling the extension and retraction of the cylinder. During the extension and retraction of the cylinder, the actual position and actual speed of the cylinder are obtained through real-time measurement and dynamic calculation, and are used as the input for the next cycle.

[0100] Continuing with the previous example, during the parallel lifting process of the loader, the controller selects the speed loop control algorithm according to the working conditions. For example, in a delicate operation scenario requiring high-precision positioning and frequent load changes, the speed loop adopts MPC control. The controller establishes a predictive model of the cylinder speed and the electromagnetic proportional valve current, sets the prediction time domain to 100 milliseconds and the control time domain to 50 milliseconds, and continuously optimizes the output current with the goal of minimizing the sum of squares of speed tracking error and the sum of squares of control increment. This allows the actual cylinder speed to respond to load disturbance changes in advance, and the tilt angle fluctuation of the horizontal fork attachment is controlled within ±0.3 degrees.

[0101] In some embodiments of the present invention, the above method further includes the following steps: When the loader's boom speed is in the first gear, the first control mode is used to control the boom cylinder to extend and retract. When the loader's boom speed is in the second gear, the second control mode is used to control the boom cylinder to extend and retract. When the loader's boom speed is in the third gear, the third control mode is used to control the boom cylinder to extend and retract.

[0102] Among them, the first gear, the second gear, and the third gear refer to three speed ranges divided according to the boom speed value. The first gear is the low speed gear, the second gear is the medium speed gear, and the third gear is the high speed gear. The first control mode refers to the control strategy with position control accuracy as the primary goal, the second control mode refers to the control strategy that takes into account both control accuracy and response speed, and the third control mode refers to the control strategy with response speed as the primary goal.

[0103] In a specific implementation of this invention, the deviation between the target position and the actual position of the hydraulic cylinder is multiplied by a proportional coefficient to output a speed setpoint. The speed loop selects at least one algorithm from model predictive control, proportional-integral control, and active disturbance rejection control. Based on the deviation between the speed setpoint and the actual speed, a current control signal is generated to drive the hydraulic cylinder. When the boom speed is in the first gear, the controller adopts a first control mode, increasing the position loop proportional coefficient and decreasing the speed loop response bandwidth to prioritize position tracking accuracy. When the boom speed is in the second gear, the controller adopts a second control mode, setting both the position loop proportional coefficient and the speed loop response bandwidth to moderate values ​​to balance accuracy and speed. When the boom speed is in the third gear, the controller adopts a third control mode, decreasing the position loop proportional coefficient and increasing the speed loop response bandwidth to prioritize rapid response.

[0104] Continuing with the aforementioned embodiment, during the loader's parallel lifting process, the controller monitors the boom lifting speed in real time. When the boom speed is in the low-speed range of 0 to 50 mm / s, the controller switches to the first control mode, adjusting the position loop proportional coefficient to (1:1.2). The speed loop uses model predictive control with a relatively long prediction time domain of 200 milliseconds to prioritize suppressing disturbances and ensure position tracking accuracy. At this time, the tilt angle fluctuation range of the fork attachment is controlled within ±0.2 degrees. When the boom speed is in the medium-speed range of 50 to 150 mm / s, the controller switches to the second control mode, adjusting the position loop proportional coefficient to (1:0.8). The speed loop model predictive control prediction time domain is shortened to 100 milliseconds, achieving a balance between accuracy and speed, and the tilt angle fluctuation range is controlled within ±0.4 degrees. When the boom speed is above 150 mm / s in the high-speed range, the controller switches to the third control mode, adjusting the position loop proportional coefficient to (1:0.5), shortening the prediction time domain of the speed loop model predictive control to 50 milliseconds, and increasing the speed loop gain. This prioritizes ensuring rapid cylinder response, keeping the tilt angle fluctuation range within ±0.6 degrees while still meeting operational requirements. It should be noted that the low-speed, medium-speed, and high-speed gears can be set according to actual needs and can also be modified based on changes and developments in the loader's structure.

[0105] The above steps construct a dual-loop control structure by connecting position loop proportional control with multiple selectable speed loop algorithms. Through a layered boom speed control strategy, priority is given to ensuring position tracking accuracy at low speeds to prevent excessive fluctuations in the fork attachment tilt angle due to control disturbances. At medium speeds, both accuracy and speed are balanced to meet routine operational needs. At high speeds, priority is given to ensuring rapid response to prevent cargo tilting due to control lag. This achieves stable and efficient operation of the parallel lifting function across the entire speed range. Figure 7 The diagram shown is a rocker arm control logic diagram provided in an embodiment of the present invention. First, the horizontal fork angle is set. The boom joint angle and rocker arm joint angle are obtained by reading the angle sensor or IMU inertial measurement unit, namely ∠A1AD and ∠ADE in the aforementioned embodiment. Then, the actual position and target position of the rocker arm cylinder are calculated, and the rocker arm cylinder is controlled to shorten or extend based on the difference between the two.

[0106] This invention achieves parallel lifting of the flat fork attachment by accurately calculating the first difference between the actual length and the target length of the boom cylinder and the second difference between the actual length and the target length of the rocker arm cylinder, and controlling the cylinders according to the first and second differences. It can achieve parallel lifting of the flat fork attachment at any horizontal angle without complex calibration. It adopts a dual-loop series control logic, which has high control accuracy and strong anti-interference ability.

[0107] This embodiment also provides a loader fork attachment lifting control device, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0108] This embodiment provides a lifting control device for a loader's horizontal fork attachment, such as... Figure 8 As shown, it includes: Information acquisition module 801 is used to acquire the target fork angle of the loader's fork attachment, the boom joint angle and rocker arm joint angle of the loader; The actual length calculation module 802 is used to calculate the actual length of the boom cylinder and the actual length of the rocker arm cylinder based on the geometric kinematic relationship and according to the boom joint angle and the rocker arm joint angle. The target length determination module 803 is used to determine the target length of the boom cylinder and the target length of the rocker arm cylinder based on the target fork angle. The difference calculation module 804 is used to calculate the first deviation value between the target length of the boom cylinder and the actual length of the boom cylinder, and the second deviation value between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder. The control module 805 is used to control the boom cylinder and rocker arm cylinder of the loader according to the first deviation value and the second deviation value, so that the flat fork attachment is lifted in parallel; wherein, the dual-loop series control logic includes position loop control logic and speed loop control logic.

[0109] In some alternative implementations, the actual length calculation module 802 includes: The coordinate system establishment unit is used to establish a coordinate system with the hinge point between the boom and the frame as the origin.

[0110] The coordinate acquisition unit is used to acquire the first coordinate of the hinge point between the tail of the boom cylinder and the frame in the coordinate system, and the second coordinate of the hinge point between the tail of the rocker arm cylinder and the frame in the coordinate system.

[0111] In some alternative implementations, the actual length calculation module 802 includes: The first calculation unit is used to calculate the boom rotation angle based on the boom joint angle and the structural constant angle of the boom. The second calculation unit is used to calculate the fourth coordinate of the boom cylinder piston rod head in the coordinate system based on the boom rotation angle; The first distance calculation unit calculates the Euclidean distance between the fourth coordinate and the first coordinate to obtain the actual length of the boom cylinder.

[0112] In some optional implementations, the actual length calculation module 802 further includes: The third calculation unit is used to calculate the coordinates of the boom-rocker hinge point based on the boom rotation angle. The boom-rocker hinge point is the hinge point between the boom and the rocker arm of the loader. The fourth calculation unit is used to calculate the first included angle formed by the three points of the boom rocker arm hinge point, the rocker arm connecting rod hinge point and the boom bucket hinge point based on the measured rocker arm joint angle and the known structural angle of the boom rocker arm. The vertex of the first included angle is the boom rocker arm hinge point. The fifth calculation unit is used to calculate the length of the first virtual side between the boom bucket hinge point and the rocker arm connecting rod hinge point using the cosine theorem based on the first included angle, the length of the rocker arm structure, and the first hinge distance. The first hinge distance is the distance between the boom rocker arm hinge point and the boom bucket hinge point. The attitude angle determination unit is used to determine the bucket attitude angle based on the length of the first virtual opposite side; The sixth calculation unit is used to calculate the length of the second virtual side between the boom rocker arm hinge point and the connecting rod bucket hinge point using the cosine theorem, based on the bucket attitude angle, the known angle of the bucket structure, the first hinge distance, and the length of the connecting rod structure. The seventh calculation unit is used to calculate the rotation angle between the piston rod head of the rocker arm cylinder and the rocker arm hinge point relative to the horizontal line based on the length of the second virtual opposite side. The coordinate determination unit is used to determine the coordinates of the hinge point of the rocker arm cylinder piston rod head based on the rotation angle and the coordinates of the boom rocker arm hinge point. The second distance calculation unit is used to calculate the Euclidean distance between the hinge point coordinates of the piston rod head of the rocker arm cylinder and the second coordinate, so as to obtain the actual length of the rocker arm cylinder.

[0113] In some alternative implementations, the position loop employs proportional control, and the speed loop control logic employs at least one of model predictive control, proportional-integral control, and active disturbance rejection control.

[0114] In some alternative embodiments, the apparatus further includes: The first mode control module is used to control the boom cylinder to extend and retract when the loader's boom speed is in the first gear. The second mode control module is used to control the boom cylinder to extend and retract when the loader's boom speed is in the second gear. The third mode control module is used to control the extension and retraction of the boom cylinder in the third control mode when the loader's boom speed is in the third gear.

[0115] In some optional implementations, the information acquisition module 801 includes: The information acquisition unit is used to acquire the boom joint angle and rocker arm joint angle of the loader through an angle sensor installed at the hinge between the boom and rocker arm of the loader, or through an IMU inertial measurement unit.

[0116] The loader fork attachment lifting control device provided in this embodiment of the invention can execute a loader fork attachment lifting control method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method. Further functional descriptions of the above modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.

[0117] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0118] The following is a detailed reference. Figure 9This diagram illustrates a suitable structural schematic for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 901, which can perform various appropriate actions and processes based on a program stored in a read-only memory (ROM) 902 or a program loaded from memory 908 into random access memory (RAM) 903. RAM 903 also stores various programs and data required for the operation of the electronic device. The processor 901, ROM 902, and RAM 903 are interconnected via a bus 904. An input / output (I / O) interface 905 is also connected to the bus 904.

[0119] Typically, the following devices can be connected to I / O interface 905: input devices 906 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 909 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 908 including, for example, magnetic tapes, hard disks, etc.; and communication devices 909. Communication device 909 allows electronic devices to exchange data via wireless or wired communication with other devices. Although Figure 9 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0120] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 909, or installed from a memory 908, or installed from a ROM 902. When the computer program is executed by a processor 901, it performs the functions defined in a loader fork attachment lifting control method according to an embodiment of the present invention.

[0121] Figure 9 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of the present invention.

[0122] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, it implements the loader fork attachment lifting control method shown in the above embodiments.

[0123] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0124] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A lifting control method for a loader's horizontal fork attachment, characterized in that, The method includes: Obtain the target fork angle of the loader's swingarm attachment, the boom joint angle of the loader, and the rocker arm joint angle; Based on the geometric kinematic relationship, the actual lengths of the boom cylinder and rocker arm cylinder are calculated according to the boom joint angle and the rocker arm joint angle. Based on the target fork angle, determine the target length of the boom cylinder and the target length of the rocker arm cylinder; Calculate the first deviation value between the target length of the boom cylinder and the actual length of the boom cylinder, and the second deviation value between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder; A dual-loop series control logic is adopted to control the boom cylinder and rocker arm cylinder of the loader according to the first deviation value and the second deviation value, so that the horizontal fork attachment is lifted in parallel; wherein, the dual-loop series control logic includes position loop control logic and speed loop control logic.

2. The method according to claim 1, characterized in that, Before calculating the actual lengths of the boom cylinder and rocker arm cylinder, the following steps are included: Establish a coordinate system with the hinge point between the boom and the frame as the origin; Obtain the first coordinate of the hinge point between the tail of the boom cylinder and the frame in the coordinate system, and the second coordinate of the hinge point between the tail of the rocker arm cylinder and the frame in the coordinate system.

3. The method according to claim 2, characterized in that, The calculation of the actual length of the boom cylinder and the rocker arm cylinder includes: Calculate the boom rotation angle based on the boom joint angle and the structural constant angle of the boom; Based on the boom rotation angle, calculate the fourth coordinate of the boom cylinder piston rod head in the coordinate system; The Euclidean distance between the fourth coordinate and the first coordinate is calculated to obtain the actual length of the boom cylinder.

4. The method according to claim 3, characterized in that, The calculation of the actual length of the boom cylinder and the rocker arm cylinder also includes: Based on the boom rotation angle, calculate the coordinates of the boom-rocker hinge point, which is the hinge point between the boom and the rocker arm of the loader. Based on the measured rocker arm joint angle and the known structural angle of the boom rocker arm, calculate the first included angle formed by the three points: the boom rocker arm hinge point, the rocker arm connecting rod hinge point, and the boom bucket hinge point. The vertex of the first included angle is the boom rocker arm hinge point. Based on the first included angle, the length of the rocker arm structure, and the first hinge distance, the length of the first virtual side between the boom bucket hinge point and the rocker arm connecting rod hinge point is calculated using the cosine theorem, wherein the first hinge distance is the distance between the boom rocker arm hinge point and the boom bucket hinge point. The bucket attitude angle is determined based on the length of the first virtual opposite side; Based on the bucket posture angle, the known angle of the bucket structure, the first hinge distance, and the length of the connecting rod structure, the length of the second virtual side between the boom rocker arm hinge point and the connecting rod bucket hinge point is calculated using the law of cosines. Based on the length of the second virtual opposite side, calculate the rotation angle of the rocker arm cylinder piston rod head and the rocker arm hinge point relative to the horizontal line; Based on the rotation angle and the coordinates of the rocker arm hinge point, determine the coordinates of the rocker arm cylinder piston rod head hinge point; The Euclidean distance between the hinge point coordinates of the piston rod head of the rocker arm cylinder and the second coordinate is calculated to obtain the actual length of the rocker arm cylinder.

5. The method according to claim 1, characterized in that, The position loop uses proportional control, and the speed loop control logic uses at least one of model predictive control, proportional-integral control, and active disturbance rejection control.

6. The method according to any one of claims 1-5, characterized in that, The method further includes: When the boom speed of the loader is in the first gear, the boom cylinder is controlled to extend and retract using the first control mode. When the boom speed of the loader is in the second gear, the boom cylinder is controlled to extend and retract using the second control mode; When the boom speed of the loader is in the third gear, the boom cylinder is controlled to extend and retract using the third control mode.

7. The method according to claim 1, characterized in that, The process of obtaining the boom joint angle and rocker arm joint angle of the loader includes: The boom joint angle and rocker arm joint angle of the loader are obtained by an angle sensor installed at the hinge between the boom and rocker arm, or by an IMU inertial measurement unit.

8. A lifting control device for a loader's horizontal fork attachment, characterized in that, The device includes: The information acquisition module is used to acquire the target fork angle of the loader's fork attachment, the boom joint angle of the loader, and the rocker arm joint angle. The actual length calculation module is used to calculate the actual length of the boom cylinder and the actual length of the rocker arm cylinder based on the geometric kinematic relationship and according to the boom joint angle and the rocker arm joint angle. The target length determination module is used to determine the target length of the boom cylinder and the target length of the rocker arm cylinder based on the target fork angle. The difference calculation module is used to calculate the first deviation value between the target length of the boom cylinder and the actual length of the boom cylinder, and the second deviation value between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder. The control module is used to control the boom cylinder and rocker arm cylinder of the loader according to the first deviation value and the second deviation value, so that the flat fork attachment is lifted in parallel; wherein, the dual-loop series control logic includes position loop control logic and speed loop control logic.

9. An electronic device, characterized in that, include: A memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, the processor executing the computer instructions to perform the method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method of any one of claims 1 to 7.

11. A computer program product, characterized in that, Includes computer instructions for causing a computer to perform the method of any one of claims 1 to 7.

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