Cantilever crane control method, processor, engineering equipment and storage medium

Abstract

The invention discloses a method for arm support control, a processor, engineering equipment and a storage medium, the method is applied to the engineering equipment, the engineering equipment comprises an arm support and a telescopic oil cylinder and a pitching oil cylinder of the arm support, and the method comprises the steps that an expected track of the tail end of the arm support is obtained; determining a first length of a telescopic oil cylinder and a second length of a pitching oil cylinder according to the expected track on the basis of a pre-constructed boom tail end kinematics model; according to the second length and the preset length of the pitching oil cylinder, the deflection deformation quantity of the cantilever crane is determined; correcting the second length of the pitching oil cylinder according to the deflection deformation quantity to obtain a target pitching oil cylinder length; and based on the first length and the target pitching oil cylinder length, the tail end of the boom is controlled to work along the expected track. The influence of deflection deformation on boom control is considered, the method can be suitable for a long and thin boom, and the boom control precision is improved.

Description

Technical Field

[0001] The present application relates to the technical field of engineering machinery, and in particular to a method, a processor, an engineering device and a storage medium for boom control. Background Art

[0002] The end position control of the boom is to ensure the working efficiency and safety of the engineering equipment. At present, it is an important development direction to develop a platform end trajectory tracking control system on engineering equipment, so that the end of the boom moves according to the desired trajectory, which can greatly improve the efficiency of completing the task. Existing research mainly applies the relevant technology of robotics to the end position control of the boom. However, for a slender boom, the existing technology does not take into account the differences in structure and drive between it and the traditional robotic arm, resulting in low control accuracy. Therefore, the boom control method in the existing technology has the problem of low control accuracy. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a method, processor, engineering equipment and machine-readable storage medium for boom control, so as to solve the problem of low control accuracy in the boom control method in the prior art.

[0004] In order to achieve the above-mentioned object, a first aspect of an embodiment of the present application provides a method for controlling a boom, which is applied to engineering equipment. The engineering equipment includes a boom and a telescopic cylinder and a pitch cylinder of the boom. The method includes:

[0005] Obtaining a desired trajectory of the end of the boom;

[0006] Based on a pre-built kinematic model of the boom end, a first length of the telescopic cylinder and a second length of the pitch cylinder are determined according to a desired trajectory;

[0007] Determining the deflection amount of the boom according to the second length and a preset pitch cylinder length;

[0008] Correcting the second length of the pitch cylinder according to the deflection deformation to obtain a target pitch cylinder length;

[0009] Based on the first length and the target pitch cylinder length, the end of the boom is controlled to operate along a desired trajectory.

[0010] In an embodiment of the present application, based on the first length and the target pitch cylinder length, the boom is controlled to operate along a desired trajectory, including: constructing a nonlinear dynamic model of the hydraulic cylinder of the boom according to the nonlinear characteristics of the hydraulic system of the boom, wherein the nonlinear characteristics include hydraulic pump characteristics, servo characteristics and cylinder friction characteristics; based on the nonlinear dynamic model, according to the first length and the target pitch cylinder length, determining the target control parameters of the boom through nonlinear model predictive control; and controlling the end of the boom to operate along the desired trajectory according to the target control parameters.

[0011] In the embodiment of the present application, the nonlinear dynamic model satisfies formula (1):

[0012]

[0013] Where m is the mass of the load carried by the cylinder, x is the length of the cylinder, and F load is the external force acting on the load, K friction is the friction coefficient of the cylinder, A cylinder is the effective area of ​​the cylinder; ΔP is the pressure difference at both ends of the cylinder.

[0014] In an embodiment of the present application, based on a nonlinear dynamic model, according to a first length and a target pitch cylinder length, target control parameters of the boom are determined through nonlinear model predictive control, including: initializing an initial state and an initial control amount of the boom; predicting a predicted state of the boom corresponding to each prediction time step within a preset time range through a nonlinear dynamic model according to the initial state and the initial control amount; determining a cylinder position tracking error corresponding to each prediction time step according to the first length and the target pitch cylinder length corresponding to the predicted state of each prediction time step, combined with the measured data of the cylinder position; setting an optimization problem with the goal of minimizing the cumulative sum of squares of the cylinder position tracking errors of each prediction time step; solving the optimization problem through a numerical optimization method based on preset constraints to obtain target control parameters.

[0015] In an embodiment of the present application, the second length of the pitch cylinder is corrected according to the deflection deformation to obtain a target pitch cylinder length, including: determining a desired pitch angle of the pitch cylinder according to a desired trajectory based on a pre-constructed boom end kinematic model; determining the target pitch cylinder length according to the desired pitch angle, the deflection deformation and the second length.

[0016] In the embodiment of the present application, the target pitch cylinder length is determined according to the expected pitch angle, the deflection deformation and the second length, including determining the target pitch cylinder length according to formula (2):

[0017]

[0018] in, is the target pitch cylinder length, lld is the second length of the pitch cylinder, A is the first preset coefficient, B is the second preset coefficient, φ is the set angle, and Δθ is the deformation amount.

[0019] In an embodiment of the present application, a method for constructing a kinematic model of the boom end includes: constructing a forward kinematic model of the boom end according to the geometric relationship of the boom; determining a trajectory coordinate model of the boom end moving along a spatial curve according to the forward kinematic model of the boom end; and obtaining the kinematic model of the boom end through an inverse kinematic equation based on the trajectory coordinate model.

[0020] A second aspect of an embodiment of the present application provides a processor configured to execute the above-mentioned method for boom control.

[0021] A third aspect of an embodiment of the present application provides an engineering equipment, including: a boom; a telescopic cylinder and a pitch cylinder of the boom; and the above-mentioned processor.

[0022] A fourth aspect of an embodiment of the present application provides a machine-readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the above-mentioned method for boom control is implemented.

[0023] The above technical solution is applied to engineering equipment, which includes a boom and a telescopic cylinder and a pitch cylinder of the boom. The desired trajectory of the end of the boom is obtained, and then based on the pre-built kinematic model of the end of the boom, the first length of the telescopic cylinder and the second length of the pitch cylinder are determined according to the desired trajectory. Then, the deflection deformation of the boom is determined according to the second length and the preset pitch cylinder length, and the second length of the pitch cylinder is further corrected according to the deflection deformation to obtain the target pitch cylinder length. Finally, based on the first length and the target pitch cylinder length, the end of the boom is controlled to operate along the desired trajectory. This application takes into account the influence of deflection deformation on boom control, and can be applied to slender booms, thereby improving the accuracy of boom control.

[0024] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0026] Figure 1 A flowchart of a method for boom control provided in an embodiment of the present application;

[0027] Figure 2 The present invention is a structural schematic diagram of an arm-type aerial work platform boom. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0029] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0031] Figure 1 A flowchart of a method for boom control provided in an embodiment of the present application is shown below. Figure 1 As shown, an embodiment of the present application provides a method for boom control, which is applied to engineering equipment. The engineering equipment includes a boom and a telescopic cylinder and a pitch cylinder of the boom. The method is applied to a processor of the engineering equipment as an example for explanation. The method may include the following steps.

[0032] Step S101, obtaining the desired trajectory of the end of the boom.

[0033] Step S102, based on the pre-built kinematic model of the boom end, determining the first length of the telescopic cylinder and the second length of the pitch cylinder according to the expected trajectory.

[0034] Step S103, determining the deflection deformation of the boom according to the second length and a preset pitch cylinder length.

[0035] Step S104: correcting the second length of the pitch cylinder according to the deflection deformation to obtain a target pitch cylinder length.

[0036] Step S105 , based on the first length and the target pitch cylinder length, controlling the end of the boom to operate along a desired trajectory.

[0037] In the embodiment of the present application, engineering equipment refers to any engineering equipment including a boom, such as a crane, an excavator, and aerial work equipment. In the embodiment of the present application, the engineering equipment also includes a telescopic cylinder and a pitch cylinder of the boom. The desired trajectory of the end of the boom refers to the target trajectory of the end of the boom of the engineering equipment that is expected to move along a specific path in space. This trajectory is usually composed of a series of position and posture points to ensure that the end effector can accurately complete the predetermined task, such as grasping, welding, assembly, etc.

[0038] Specifically, in order to make the end of the boom operate according to the expected trajectory, after obtaining the expected trajectory of the end of the boom, the embodiment of the present application can determine the first length of the telescopic cylinder and the second length of the pitch cylinder according to the expected trajectory based on the pre-constructed kinematic model of the end of the boom. Among them, the kinematic model of the end of the boom is a model that expresses the correspondence between the coordinates of the end of the boom and the cylinder length of the telescopic cylinder of the boom, the cylinder length of the pitch cylinder, and the rated pitch angle of the pitch cylinder of the boom. Since the expected trajectory is composed of multiple trajectory points, the coordinates of each expected trajectory point are determined. Therefore, according to the coordinates of each trajectory point in the expected trajectory, the first length of the telescopic cylinder of the boom and the second length of the pitch cylinder corresponding to each expected trajectory point can be determined through the kinematic model of the end of the boom. In this way, the corresponding length of the cylinder can be quickly determined according to the trajectory of the end of the boom based on the pre-constructed kinematic model of the end of the boom.

[0039] Furthermore, considering the influence of the deflection of the boom on the position control of the boom, especially for a slender boom, its deflection deformation has a greater influence on the control of the boom. It can be understood that the deflection deformation of the boom mainly occurs in the pitch direction. In order to improve the accuracy of the boom control, the embodiment of the present application can determine the deflection deformation of the boom according to the second length of the pitch cylinder of the boom and the preset pitch cylinder length. Among them, the preset pitch cylinder length is a given value of the pitch cylinder of the boom after compensating for the deflection, which can be set according to the actual situation, through experiments or operational experience.

[0040] Next, the processor can correct the second length of the pitch cylinder according to the deflection deformation of the boom pitch cylinder to obtain a target pitch cylinder length, that is, the corrected pitch cylinder length. Finally, the control amount of the telescopic cylinder and the pitch cylinder of the boom is determined according to the first length of the telescopic cylinder and the target pitch cylinder length, and the telescopic cylinder and the pitch cylinder are controlled according to the control amount, so that the end of the boom operates along the desired trajectory.

[0041] In this way, the embodiment of the present application can effectively improve the accuracy of the position control of the end of the boom by processing the influence of the deflection deformation on the end position control of the boom.

[0042] The above technical solution is applied to engineering equipment, which includes a boom and a telescopic cylinder and a pitch cylinder of the boom. The desired trajectory of the end of the boom is obtained, and then based on the pre-built kinematic model of the end of the boom, the first length of the telescopic cylinder and the second length of the pitch cylinder are determined according to the desired trajectory. Then, the deflection deformation of the boom is determined according to the second length and the preset pitch cylinder length, and the second length of the pitch cylinder is further corrected according to the deflection deformation to obtain the target pitch cylinder length. Finally, based on the first length and the target pitch cylinder length, the end of the boom is controlled to operate along the desired trajectory. This application takes into account the influence of deflection deformation on boom control, and can be applied to slender booms, thereby improving the accuracy of boom control.

[0043] In an embodiment of the present application, a method for constructing a kinematic model of the boom end includes: constructing a forward kinematic model of the boom end according to the geometric relationship of the boom; determining a trajectory coordinate model of the boom end moving along a spatial curve according to the forward kinematic model of the boom end; and obtaining the kinematic model of the boom end through an inverse kinematic equation based on the trajectory coordinate model.

[0044] It is understandable that there are certain differences in the construction of the kinematic model of the boom end for different types of booms. Specifically, taking the boom of a boom-type aerial work platform as an example, the pitch, extension and rotation of the boom of the boom-type aerial work platform are achieved by controlling two hydraulic cylinders and a rotary hydraulic motor. Figure 2 The structure diagram of the boom of an aerial work platform is shown in FIG. l is the length of the boom's pitch cylinder, l s represents the length of the telescopic cylinder of the boom; L1 and L2 are known values, which are determined by the structure of the boom-type aerial work platform; θ is the angle between the boom and the X-axis, φ is the angle between the line segment with a side length of L2 and the X-axis, and φ is a known value. Assume that the linear velocity at the end of the boom is v, and α is the angle between the linear velocity v and the X-axis.

[0045] According to the geometric relationship of the boom structure, the forward kinematic model of the boom end satisfies formula (1):

[0046]

[0047] When the end of the boom moves along a space curve, the real-time trajectory coordinate model satisfies formula (2):

[0048]

[0049] Among them, l s0, l l0 are the initial lengths of the telescopic cylinder and the pitch cylinder, respectively, and θ0 represents the initial pitch angle of the pitch cylinder of the boom. d , α d are the set linear speed and its angle with the X-axis respectively.

[0050] Furthermore, according to formula (2), the real-time reference trajectory of the boom extension and pitch cylinder can be obtained through the inverse kinematics equation, that is, the kinematic model of the boom end satisfies formula (3):

[0051]

[0052] Among them, l sd is the expected length of the telescopic cylinder of the boom, l ld θ is the expected length of the boom's pitch cylinder. d is the desired pitch angle of the boom's pitch cylinder.

[0053] In this way, by constructing the kinematic model of the boom end, a model support is provided for subsequent data processing, which is beneficial to improving computational efficiency.

[0054] In an embodiment of the present application, the second length of the pitch cylinder is corrected according to the deflection deformation to obtain a target pitch cylinder length, including: determining a desired pitch angle of the pitch cylinder according to a desired trajectory based on a pre-constructed boom end kinematic model; determining the target pitch cylinder length according to the desired pitch angle, the deflection deformation and the second length.

[0055] In the embodiment of the present application, the target pitch cylinder length is determined according to the expected pitch angle, the deflection deformation and the second length, including determining the target pitch cylinder length according to formula (4):

[0056]

[0057] in, is the length of the pitch cylinder after correction, i.e. the target pitch cylinder length, l ld is the second length of the pitch cylinder, that is, the expected length of the pitch cylinder, A is the first preset coefficient, B is the second preset coefficient, φ is the set angle, and Δθ is the deflection deformation.

[0058] It can be understood that when the end of the boom carries a load, deflection deformation will occur during the movement of the boom, causing the position of the end of the boom to shake, or displacement interference, which is mainly manifested as the deflection deformation of the boom pitch cylinder. Taking the boom of an aerial work platform as an example, when the work platform is working with a load, the boom will deform during the movement, causing shaking and displacement interference at its end position.

[0059] Specifically, let the change in the boom pitch angle caused by the deflection deformation be Δθ, that is, the deflection deformation of the boom. When the change in the pitch angle is not large, Δθ can be approximately calculated as shown in formula (5):

[0060]

[0061] Among them, l ld is the second length of the pitch cylinder, The preset pitch cylinder length is the given value of the pitch cylinder of the boom after compensating for deflection. This value can be set according to actual conditions, through tests or operational experience.

[0062] Furthermore, according to the above formula (3), formula (6) can be obtained:

[0063]

[0064] Next, by combining formula (5) and formula (6), we can get formula (7):

[0065]

[0066] in, is the length of the pitch cylinder after correction, i.e. the target pitch cylinder length, l ld is the second length of the pitch cylinder, i.e. the expected length of the pitch cylinder, φ is a known value, i.e. the set angle, and Δθ is the deflection deformation. Then the first preset coefficient in formula (4) is The second preset coefficient

[0067] Thus, the deflection deformation of the boom can be determined according to the above formula (5). Furthermore, according to the pre-built boom end kinematic model, i.e., formula (3), the desired pitch angle of the pitch cylinder is determined according to the desired trajectory. Finally, according to the desired pitch angle, the deflection deformation and the second length, the target pitch cylinder length is determined by formula (4) or (7). Thus, as long as the pitch cylinder of the boom is controlled by the corrected target pitch cylinder length, the influence of the deflection deformation can be eliminated when the boom end position is controlled.

[0068] In an embodiment of the present application, based on the first length and the target pitch cylinder length, the boom is controlled to operate along a desired trajectory, including: constructing a nonlinear dynamic model of the hydraulic cylinder of the boom according to the nonlinear characteristics of the hydraulic system of the boom, wherein the nonlinear characteristics include hydraulic pump characteristics, servo characteristics and cylinder friction characteristics; based on the nonlinear dynamic model, according to the first length and the target pitch cylinder length, determining the target control parameters of the boom through nonlinear model predictive control; and controlling the end of the boom to operate along the desired trajectory according to the target control parameters.

[0069] It can be understood that in order to improve the control accuracy of the electro-hydraulic system and thus improve the control accuracy of the end position of the boom, the embodiment of the present application can establish a nonlinear dynamic model of the hydraulic cylinder of the boom, and consider the nonlinear characteristics of the hydraulic system when designing the controller, including hydraulic pump characteristics, servo characteristics, and cylinder friction characteristics.

[0070] Specifically, assuming that the output pressure P of the hydraulic pump is pump It is proportional to the motor speed n, so the hydraulic pump characteristic can be expressed as formula (8):

[0071] P pump =K pump ·n; (8)

[0072] Among them, K pump is the proportionality factor of the hydraulic pump.

[0073] Assume that the flow rate Q of the servo valve is valve With input voltage or current u valve The servo valve characteristic can be expressed as formula (9):

[0074] Q valve =K valve ·u valve ; (9)

[0075] Among them, K valve is the proportionality factor of the servo valve.

[0076] The dynamic equation of the cylinder can be expressed as formula (10):

[0077]

[0078] Where m is the mass of the load carried by the cylinder, x is the cylinder position, i.e. the cylinder length, and F load represents the external force acting on the load, F friction Indicates the friction force of the cylinder, F hydraulic Indicates the hydraulic pressure generated by the cylinder.

[0079] Furthermore, assuming that the effective area of ​​the cylinder is A cylinder , then the hydraulic pressure F hydraulic It can be expressed as formula (11):

[0080] F hydraulic =A cylinder ·ΔP; (11)

[0081] Where ΔP is the pressure difference across the cylinder.

[0082] Cylinder flow rate Q cylinder It is proportional to the rate of position change and can be expressed as formula (12):

[0083] Q cylinder =A cylinder ·dx / dt; (12)

[0084] Cylinder friction force F friction It is proportional to the cylinder speed and can be expressed as formula (13):

[0085]

[0086] Among them, K friction is the coefficient of friction.

[0087] In the embodiment of the present application, based on the above formulas (8) to (13) integrated together, it can be determined that the nonlinear dynamic model of the hydraulic system of the boom satisfies formula (14):

[0088]

[0089] Where m is the mass of the load carried by the cylinder, x is the length of the cylinder, and F load is the external force acting on the load, K friction is the friction coefficient of the cylinder, A cylinder is the effective area of ​​the cylinder; ΔP is the pressure difference at both ends of the cylinder.

[0090] Among them, ΔP and Q valve The relationship can be obtained based on the continuity equation of the hydraulic system and the servo valve characteristics. For example, in a simplified case, it can be assumed that: ΔP = P pump -P return ;Q valve =Q cylinder Among them, P return It is the pressure at the oil return end of the cylinder.

[0091] In an embodiment of the present application, based on a nonlinear dynamic model, according to a first length and a target pitch cylinder length, target control parameters of the boom are determined through nonlinear model predictive control, including: initializing an initial state and an initial control amount of the boom; predicting a predicted state of the boom corresponding to each prediction time step within a preset time range through a nonlinear dynamic model according to the initial state and the initial control amount; determining a cylinder position tracking error corresponding to each prediction time step according to the first length and the target pitch cylinder length corresponding to the predicted state of each prediction time step, combined with the measured data of the cylinder position; setting an optimization problem with the goal of minimizing the cumulative sum of squares of the cylinder position tracking errors of each prediction time step; solving the optimization problem through a numerical optimization method based on preset constraints to obtain target control parameters.

[0092] It can be understood that in order to achieve high-precision position tracking control of the hydraulic cylinder, the embodiment of the present application can combine the nonlinear dynamic model of the hydraulic cylinder of the boom with the nonlinear model predictive control (NMPC) to achieve high-precision control of the end position of the boom.

[0093] Specifically, the nonlinear dynamic model of the hydraulic cylinder is first expressed in state space form:

[0094]

[0095] in:

[0096]

[0097] ΔP=P pump -P return =K pump ·nP return ;

[0098]

[0099] The following takes the position control of the boom's pitch cylinder as an example to illustrate the optimization calculation process of the control quantity:

[0100] 1. Initialization

[0101] Set the initial state x(0) and initial control input u(0). The initial state is the initial position of each cylinder, and the initial control input is generally set to 0.

[0102] 2. Predicting future states

[0103] Use a nonlinear dynamics model to predict future states, considering the prediction time horizon (N steps):

[0104] x(t+k+1)=x(t+k)+Δt·f(x(t+k),u(t+k),p(t+k)),

[0105] k=0,1,…,N-1;

[0106] Make predictions at each time step k until the end of the prediction time horizon.

[0107] 3. Calculate tracking error

[0108] For each prediction time step, the target pitch cylinder length is determined according to the method for boom control in the above embodiment. According to the cylinder position sensor, the actual position of the cylinder is l ldr (t), the cylinder position tracking error can be calculated:

[0109]

[0110] 4. Set optimization questions

[0111] According to the setting of the nonlinear model predictive control optimization problem, the control input sequence u(k) is optimized within a limited prediction time range (N steps) to minimize the cumulative sum of squares of the cylinder position tracking error. The optimization problem can be expressed as:

[0112]

[0113] x min ≤x(t)≤x max ;

[0114] u min ≤u(t)≤u max ;

[0115] Where i = 0, 1, ..., N-1; λ is a parameter that weighs the tracking error and the control input size. The setting of the constraint conditions takes into account the physical constraints of the system, such as the position, speed and displacement of the servo valve core.

[0116] 5. Solve the control input sequence

[0117] In view of the above optimization problem, numerical optimization methods (such as SQP, interior point method, etc.) are used to solve the optimization problem and obtain the optimal control input sequence u(k).

[0118] 6. Application Control Input

[0119] The first control input u(0) of the optimized control input sequence u(k) is applied to the system.

[0120] 7. Update Status

[0121] Update the system state to reflect the actual state after applying the control input:

[0122] x(t+1)=x(t)+Δt·f(x(t),u(t),p(t));

[0123] And enter the next control cycle.

[0124] In this way, considering the nonlinearity, time delay and other characteristics of the hydraulic system, the embodiment of the present application proposes a control scheme based on nonlinear model predictive control, which directly handles nonlinear constraints in the optimization problem, such as the position range and speed limit of the hydraulic cylinder. This allows the control to provide higher control performance while meeting the physical limitations of the hydraulic system. At the same time, the proposed control scheme takes into account the uncertainty and interference of the system during the prediction and optimization process, thereby achieving better robustness. In practical applications, the impact of external disturbances on system performance can be reduced, ensuring the stable operation of the aerial work platform in complex environments.

[0125] An embodiment of the present application also provides a processor configured to execute the method for boom control in the above-mentioned implementation.

[0126] An embodiment of the present application also provides an engineering equipment, including: a boom; a telescopic cylinder and a pitch cylinder of the boom; and the processor in the above embodiment.

[0127] An embodiment of the present application also provides a machine-readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the method for boom control in the above-mentioned embodiment is implemented.

[0128] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0129] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of the processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0130] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0131] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0132] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0133] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0134] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0135] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0136] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for boom control, characterized in that: Applied to engineering equipment, the engineering equipment includes a boom and a telescopic cylinder and a pitch cylinder of the boom, the method includes: Obtaining a desired trajectory of the end of the boom; Based on a pre-built kinematic model of the boom end, determining a first length of the telescopic cylinder and a second length of the pitch cylinder according to the desired trajectory; Determining the deflection amount of the boom according to the second length and a preset pitch cylinder length; Correcting the second length of the pitch cylinder according to the deflection deformation to obtain a target pitch cylinder length; Based on the first length and the target pitch cylinder length, the end of the boom is controlled to operate along the desired trajectory.

2. The method according to claim 1, characterized in that: The controlling the boom to operate along the desired trajectory based on the first length and the target pitch cylinder length includes: Constructing a nonlinear dynamic model of the hydraulic cylinder of the boom according to the nonlinear characteristics of the hydraulic system of the boom, wherein the nonlinear characteristics include hydraulic pump characteristics, servo characteristics and cylinder friction characteristics; Based on the nonlinear dynamic model, according to the first length and the target pitch cylinder length, determining the target control parameter of the boom through nonlinear model predictive control; The end of the boom is controlled to operate along the desired trajectory according to the target control parameter.

3. The method according to claim 2, characterized in that The nonlinear dynamic model satisfies formula (1): Where m is the mass of the load carried by the cylinder, x is the length of the cylinder, and F load is the external force acting on the load, K friction is the friction coefficient of the cylinder, A cylinder is the effective area of ​​the cylinder; ΔP is the pressure difference at both ends of the cylinder.

4. The method according to claim 2, characterized in that: The method of determining the target control parameters of the boom by nonlinear model predictive control based on the nonlinear dynamic model and according to the first length and the target pitch cylinder length includes: Initializing the initial state and initial control amount of the boom; According to the initial state and the initial control amount, predicting the predicted state of the boom corresponding to each prediction time step within a preset time range through the nonlinear dynamic model; Determine the cylinder position tracking error corresponding to each prediction time step according to the first length and the target pitch cylinder length corresponding to the prediction state of each prediction time step and the measured data of the cylinder position; The optimization problem is set up with the goal of minimizing the cumulative sum of squares of the cylinder position tracking errors at each prediction time step; Based on preset constraints, the optimization problem is solved by a numerical optimization method to obtain the target control parameters.

5. The method according to claim 1, characterized in that The step of correcting the second length of the pitch cylinder according to the deflection deformation to obtain a target pitch cylinder length includes: Based on the pre-built boom end kinematic model, determining the expected pitch angle of the pitch cylinder according to the expected trajectory; The target pitch cylinder length is determined according to the desired pitch angle, the deflection deformation amount and the second length.

6. The method according to claim 5, characterized in that Determining the target pitch cylinder length according to the expected pitch angle, the deflection deformation and the second length includes determining the target pitch cylinder length according to formula (2): in, is the target pitch cylinder length, l ld is the second length of the pitch cylinder, A is the first preset coefficient, B is the second preset coefficient, φ is the set angle, and Δθ is the deformation amount.

7. The method according to claim 1, characterized in that The method for constructing the kinematic model of the boom end includes: Constructing a forward kinematics model of the boom end of the boom according to the geometric relationship of the boom; Determine a trajectory coordinate model of the boom end moving along a space curve according to the forward kinematics model of the boom end; According to the trajectory coordinate model, the kinematic model of the boom end is obtained through the inverse kinematics equation.

8. A processor, characterized in that: The method is configured to execute the method for boom control according to any one of claims 1 to 7.

9. An engineering equipment, characterized in that: include: Boom; The telescopic cylinder and the pitch cylinder of the boom; A processor according to claim 8.

10. A machine-readable storage medium storing a program or an instruction, characterized in that: When the program or the instruction is executed by a processor, the method for boom control according to any one of claims 1 to 7 is implemented.

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