Method, processor, engineering device and storage medium for boom control

Abstract

The application discloses a method, a processor, an engineering device and a storage medium for arm support control, which are applied to an engineering device, the engineering device comprising an arm support, a telescopic oil cylinder and a luffing oil cylinder of the arm support, and belongs to the technical field of engineering machinery. The method comprises the following steps: acquiring a desired trajectory of the end of the arm support; determining a first length of the telescopic oil cylinder and a second length of the luffing oil cylinder according to the desired trajectory based on a pre-constructed kinematic model of the end of the arm support; determining a deflection deformation variable of the arm support according to the second length and a preset luffing oil cylinder length; correcting the second length of the luffing oil cylinder according to the deflection deformation variable to obtain a target luffing oil cylinder length; and controlling the end of the arm support to work along the desired trajectory based on the first length and the target luffing oil cylinder length. The application considers the influence of deflection deformation on arm support control, can be applied to a slender arm support, and improves the precision of arm support control.

Description

TECHNICAL FIELD

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

[0002] The end position control of the boom is to ensure the work efficiency and safety of the engineering device. At present, developing a platform end trajectory tracking control system on the engineering device is an important development direction, so that the end of the boom moves according to the expected trajectory, which can greatly improve the efficiency of completing the work task. The existing research mainly applies the related technology of robotics to the end position control of the boom. However, for a slender boom, the existing technology does not consider the difference between its structure and driving and those of the traditional mechanical arm, resulting in low control precision. Therefore, the boom control method in the prior art has the problem of low control precision. SUMMARY

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

[0004] In order to achieve the above-mentioned purpose, the first aspect of the embodiments of the present application provides a method for boom control, applied to an engineering device, the engineering device comprising a boom, a telescopic cylinder and a luffing cylinder of the boom, the method comprising:

[0005] obtaining an expected trajectory of the end of the boom;

[0006] determining a first length of the telescopic cylinder and a second length of the luffing cylinder according to the expected trajectory based on a pre-constructed kinematic model of the end of the boom;

[0007] determining a deflection deformation variable of the boom according to the second length and a preset luffing cylinder length;

[0008] correcting the second length of the luffing cylinder according to the deflection deformation variable to obtain a target luffing cylinder length;

[0009] controlling the end of the boom to work along the expected trajectory based on the first length and the target luffing cylinder length.

[0010] In the embodiment of the present application, based on the first length and the target tilt oil cylinder length, the arm frame is controlled to work along the expected trajectory, comprising: constructing a nonlinear dynamics model of the hydraulic cylinder of the arm frame according to the nonlinear characteristics of the hydraulic system of the arm frame, wherein the nonlinear characteristics include hydraulic pump characteristics, servo characteristics and oil cylinder friction characteristics; based on the nonlinear dynamics model, according to the first length and the target tilt oil cylinder length, the target control parameter of the arm frame is determined through nonlinear model predictive control; the end of the arm frame is controlled to work along the expected trajectory according to the target control parameter.

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

[0012]

[0013] Wherein, m is the mass of the load carried by the oil cylinder, x is the length of the oil cylinder, F load is the external force acting on the load, K friction is the oil cylinder friction coefficient, A cylinder is the effective area of the oil cylinder; ΔP is the pressure difference between the two ends of the oil cylinder.

[0014] In the embodiment of the present application, based on the nonlinear dynamics model, according to the first length and the target tilt oil cylinder length, the target control parameter of the arm frame is determined through nonlinear model predictive control, comprising: initializing the initial state and the initial control amount of the arm frame; according to the initial state and the initial control amount, the predicted state of the arm frame corresponding to each prediction time step within a preset time range is predicted through the nonlinear dynamics model; according to the first length and the target tilt oil cylinder length corresponding to each prediction time step, and combined with the measured data of the oil cylinder position, the oil cylinder position tracking error corresponding to each prediction time step is determined; an optimization problem is set with the goal of minimizing the cumulative square sum of the oil cylinder position tracking error of each prediction time step; based on the preset constraint condition, the optimization problem is solved through a numerical optimization method to obtain the target control parameter.

[0015] In the embodiment of the present application, the second length of the tilt oil cylinder is corrected according to the deflection deformation variable to obtain the target tilt oil cylinder length, comprising: determining the expected tilt angle of the tilt oil cylinder according to the expected trajectory based on the pre-constructed kinematics model of the arm frame; determining the target tilt oil cylinder length according to the expected tilt angle, the deflection deformation variable and the second length.

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

[0017]

[0018] Wherein, is the target tilt oil cylinder length, lld A is a first preset coefficient, B is a second preset coefficient, φ is a set angle, and Δθ is a deformation variable.

[0019] In the embodiment of the present application, the method for constructing the arm rack end kinematics model comprises: constructing an arm rack end forward kinematics model of the arm rack according to the geometric relationship of the arm rack; determining a trajectory coordinate model of the arm rack end along a space curve according to the arm rack end forward kinematics model; and obtaining the arm rack end kinematics model through an inverse kinematics equation according to the trajectory coordinate model.

[0020] The second aspect of the embodiment of the present application provides a processor configured to execute the above-mentioned method for arm rack control.

[0021] The third aspect of the embodiment of the present application provides an engineering equipment, comprising: an arm rack; a telescopic oil cylinder and a tilt oil cylinder of the arm rack; and the above-mentioned processor.

[0022] The fourth aspect of the embodiment of the present application provides a machine readable storage medium, and the machine readable storage medium stores programs or instructions, and the programs or instructions are executed by the processor to realize the above-mentioned method for arm rack control.

[0023] The above-mentioned technical solution is applied to the engineering equipment, the engineering equipment comprises an arm rack and a telescopic oil cylinder and a tilt oil cylinder of the arm rack, the desired trajectory of the end of the arm rack is obtained, then the first length of the telescopic oil cylinder and the second length of the tilt oil cylinder are determined according to the desired trajectory based on the pre-constructed arm rack end kinematics model. Then the deflection deformation variable of the arm rack is determined according to the second length and the preset tilt oil cylinder length, the second length of the tilt oil cylinder is further corrected according to the deflection deformation variable to obtain a target tilt oil cylinder length, and finally the end of the arm rack is controlled to work along the desired trajectory based on the first length and the target tilt oil cylinder length. The present application considers the influence of the deflection deformation on the arm rack control, can be applied to the slender arm rack, and improves the precision of the arm rack control.

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

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

[0026] Figure 1 A flowchart of a method for arm rack control provided by the embodiments of the present application is shown;

[0027] Figure 2 A structural schematic diagram of an arm type aerial work platform arm rack is shown. DETAILED DESCRIPTION

[0028] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for clear, complete description of the technical solutions in the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain and describe the embodiments of the present application and should not be used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present 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, etc.), the directional indications are only used to explain the relative positional relationship, motion condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0030] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes and should not be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0031] Figure 1 A flowchart of a method for boom control provided by the embodiments of the present application is shown. As shown in Figure 1 The embodiments of the present application provide a method for boom control, which is applied to an engineering equipment including a boom, a telescopic cylinder and a luffing cylinder of the boom. The method is described by taking a processor of the engineering equipment as an example, and the method can include the following steps.

[0032] In step S101, a desired trajectory of a terminal end of the boom is acquired.

[0033] In step S102, a first length of the telescopic cylinder and a second length of the luffing cylinder are determined according to the desired trajectory based on a pre-constructed kinematic model of the terminal end of the boom.

[0034] In step S103, a deflection deformation variable of the boom is determined according to the second length and a preset luffing cylinder length.

[0035] Step S104, the second length of the luffing cylinder is corrected according to the deflection deformation variable to obtain a target luffing cylinder length.

[0036] Step S105, based on the first length and the target luffing cylinder length, the end of the boom is controlled to work along the desired trajectory.

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

[0038] Specifically, in order to make the end of the boom work according to the desired trajectory, the embodiments of the present application can determine the first length of the telescopic cylinder and the second length of the luffing cylinder according to the desired trajectory after obtaining the desired trajectory of the end of the boom, according to the pre-constructed kinematic model of the end of the boom. Wherein, the kinematic model of the end of the boom is a model expressing the corresponding relationship between the coordinates of the end of the boom and the cylinder length of the telescopic cylinder, the cylinder length of the luffing cylinder, and the rated luffing angle of the luffing cylinder of the boom. Since the desired trajectory is composed of multiple trajectory points, the coordinates of each trajectory point are determined, therefore, according to the coordinates of each trajectory point in the desired trajectory, the first length of the telescopic cylinder and the second length of the luffing cylinder corresponding to each trajectory point can be determined through the kinematic model of the end of the boom. In this way, according to the pre-constructed kinematic model of the end of the boom, the corresponding lengths of the cylinders can be quickly determined according to the trajectory of the end of the boom.

[0039] Further, considering the influence of the deflection of the boom on the position control of the boom, especially for the slender boom, the 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 luffing direction, in order to improve the accuracy of the control of the boom, the embodiments of the present application can determine the deflection deformation variable of the boom according to the second length of the luffing cylinder of the boom and the preset luffing cylinder length. Wherein, the preset luffing cylinder length is a given value of the luffing cylinder of the boom after compensating for the deflection, which can be set according to the actual situation through test or operation experience.

[0040] Then, the processor can correct the second length of the luffing cylinder according to the deflection deformation variable of the luffing cylinder of the boom to obtain a target luffing cylinder length, that is, the cylinder length of the luffing cylinder after correction. Finally, the control amount of the telescopic cylinder and the luffing cylinder of the boom is determined according to the first length of the telescopic cylinder and the target luffing cylinder length, and the telescopic cylinder and the luffing cylinder are controlled respectively according to the control amount, so that the end of the boom works along the desired trajectory.

[0041] Thus, 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 position control of the end of the boom.

[0042] The above technical solution is applied to an engineering device, which comprises a boom and telescopic and luffing cylinders of the boom. The desired trajectory of the end of the boom is obtained, and then the first length of the telescopic cylinder and the second length of the luffing cylinder are determined based on a pre-constructed kinematic model of the end of the boom according to the desired trajectory. Then, the deflection deformation variable of the boom is determined according to the second length and a preset luffing cylinder length, and the second length of the luffing cylinder is further corrected according to the deflection deformation variable to obtain a target luffing cylinder length. Finally, the end of the boom is controlled to work along the desired trajectory based on the first length and the target luffing cylinder length. The present application considers the influence of the deflection deformation on the control of the boom, can be applied to a slender boom, and improves the accuracy of the control of the boom.

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

[0044] It can be understood that the construction of the kinematic model of the end of the boom will be different for different types of booms. Specifically, the boom of the aerial work platform is taken as an example for illustration. The luffing, telescoping and slewing actions of the boom of the aerial work platform are realized by controlling two hydraulic cylinders and a slewing hydraulic motor. Figure 2 A structural schematic diagram of a boom of an aerial work platform, wherein, l l L1 is the length of the luffing cylinder of the boom, l s L2 is the length of the telescopic cylinder of the boom; L1 and L2 are known values, which are determined by the structure of the aerial work platform; θ is the included angle between the boom and the X axis, φ is the included angle between the line segment with the length of L2 and the X axis, and φ is a known value. It is assumed that the linear velocity of 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 structure of the boom, the forward kinematic model of the end of the boom satisfies formula (1):

[0046]

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

[0048]

[0049] L1 is the length of the luffing cylinder of the boom, l s0, l l0 respectively represent the initial length of the telescopic cylinder and the luffing cylinder, and θ0 represents the initial luffing angle of the luffing cylinder of the boom. d , α d respectively represent the set linear velocity and the included angle thereof with the X-axis.

[0050] Further, the real-time reference trajectory of the telescopic and luffing cylinders of the boom can be obtained through the inverse kinematics equation according to formula (2), that is, the boom end kinematics model satisfies formula (3):

[0051]

[0052] wherein, l sd is the expected length of the telescopic cylinder of the boom, l ld is the expected length of the luffing cylinder of the boom, and θ d is the expected luffing angle of the luffing cylinder of the boom.

[0053] In this way, by constructing the boom end kinematics model of the boom, model support is provided for subsequent data processing, which is conducive to improving the operation efficiency.

[0054] In the embodiment of the present application, the second length of the luffing cylinder is corrected according to the deflection deformation variable to obtain a target luffing cylinder length, comprising: determining the expected luffing angle of the luffing cylinder according to the expected trajectory based on the pre-constructed boom end kinematics model; and determining the target luffing cylinder length according to the expected luffing angle, the deflection deformation variable and the second length.

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

[0056]

[0057] wherein, is the length of the corrected luffing cylinder, that is, the target luffing cylinder length, l ld is the second length of the luffing cylinder, that is, the expected length of the luffing cylinder, A is a first preset coefficient, B is a second preset coefficient, φ is a set angle, and Δθ is a deflection deformation variable.

[0058] It can be understood that when the boom end carries a load, deflection deformation will occur in the process of boom movement, causing the position of the boom end to shake or displace, mainly in the form of deflection deformation of the luffing cylinder of the boom. Taking the boom of the aerial work platform as an example, when the working platform works with a load, the boom will deform in the process of movement, causing the end position to shake and displace.

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

[0060]

[0061] wherein, l ld is the second length of the luffing cylinder, is the preset luffing cylinder length, which is a given value of the luffing cylinder of the boom after compensation of the deflection, and the value can be set according to actual conditions through experiments or operation experience.

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

[0063]

[0064] Then, formula (7) can be obtained by combining formula (5) and formula (6):

[0065]

[0066] wherein, is the length of the corrected luffing cylinder, that is, the target luffing cylinder length, l ld is the second length of the luffing cylinder, that is, the expected length of the luffing cylinder, φ is a known value, that is, the set angle, and Δθ is the deflection deformation. Then, the first preset coefficient in formula (4) the second preset coefficient

[0067] In this way, the deflection deformation of the boom can be determined according to formula (5) above, further, the expected luffing angle of the luffing cylinder can be determined according to the expected trajectory based on the pre-constructed kinematic model of the end of the boom, that is, formula (3), and finally the target luffing cylinder length can be determined through formula (4) or (7) according to the expected luffing angle, the deflection deformation and the second length. In this way, as long as the luffing cylinder of the boom is controlled through the corrected target luffing cylinder length, the influence of the deflection deformation can be eliminated in the position control of the end of the boom.

[0068] In the embodiments of the present application, the boom is controlled to operate along the expected trajectory based on the first length and the target luffing cylinder length, including: constructing a nonlinear dynamics 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 the characteristics of the hydraulic pump, the servo characteristics and the friction characteristics of the cylinder; determining the target control parameters of the boom through nonlinear model predictive control based on the first length and the target luffing cylinder length based on the nonlinear dynamics model; and controlling the end of the boom to operate along the expected trajectory according to the target control parameters.

[0069] It is understandable that, in order to improve the control accuracy of the electro-hydraulic system and thus improve the control accuracy of the boom end position, the embodiments of this application can establish a nonlinear dynamic model of the boom's hydraulic cylinder, and consider the nonlinear characteristics of the hydraulic system when designing the controller, including hydraulic pump characteristics, servo characteristics and cylinder friction characteristics, etc.

[0070] Specifically, assuming the output pressure P of the hydraulic pump pump The hydraulic pump characteristics are proportional to the motor speed n, and can be expressed as formula (8):

[0071] P pump =K pump ·n; (8)

[0072] Among them, K pump It is the proportional coefficient of the hydraulic pump.

[0073] Assume the flow rate Q of the servo valve valve With input voltage or current u valve Proportional to the characteristic of the servo valve, it can be expressed as formula (9):

[0074] Q valve =K valve ·u valve (9)

[0075] Among them, K valve It is the proportional coefficient of the servo valve.

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

[0077]

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

[0079] Furthermore, assume the effective area of ​​the hydraulic cylinder is A. cylinder Then the hydraulic pressure F hydraulic This can be expressed as formula (11):

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

[0081] Where ΔP is the pressure difference between the two ends of the cylinder.

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

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

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

[0085]

[0086] wherein, K friction is the friction coefficient.

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

[0088]

[0089] wherein, m is the mass of the load carried by the cylinder, x is the length of the cylinder, 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 between the two ends of the cylinder.

[0090] wherein, the relationship between ΔP and Q valve can be obtained according to the continuity equation of the hydraulic system and the servo valve characteristics. For example, in the simplified case, it can be assumed that: ΔP = P pump -P return ; Q valve = Q cylinder . Wherein, P return is the pressure of the cylinder return oil end.

[0091] In the embodiment of the present application, based on the nonlinear dynamics model, according to the first length and the target luffing cylinder length, the target control parameter of the boom is determined through the nonlinear model predictive control, including: initializing the initial state and the initial control amount of the boom; according to the initial state and the initial control amount, the predicted state of the boom corresponding to each prediction time step within a preset time range is predicted through the nonlinear dynamics model; according to the first length and the target luffing cylinder length corresponding to each prediction time step, and combining the measured data of the cylinder position, the cylinder position tracking error corresponding to each prediction time step is determined; an optimization problem is set with the target of minimizing the cumulative sum of squares of the cylinder position tracking errors of each prediction time step; based on the preset constraint condition, the optimization problem is solved through a numerical optimization method to obtain the target control parameter.

[0092] It is understood that, in order to achieve high-precision position tracking control of hydraulic cylinders, the embodiments of this application can combine the nonlinear dynamic model of the boom's hydraulic cylinders with nonlinear model predictive control (NMPC) to achieve high-precision control of the boom end position.

[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 example, using the position control of the boom's pitch cylinder, illustrates the optimization calculation process for the control quantity:

[0100] 1. Initialization

[0101] Set the initial state x(0) and the 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] Predicting future states using a nonlinear dynamics model, considering the prediction time range (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 a prediction at each time step k until the prediction time range ends.

[0107] 3. Calculate the tracking error

[0108] For each predicted time step, the target pitch cylinder length is determined according to the method for boom control described in the above implementation scheme. The actual position of the hydraulic cylinder is obtained from the cylinder position sensor as l. ldr (t), then the cylinder position tracking error can be calculated:

[0109]

[0110] 4. Setting optimization problem

[0111] According to the setting of the nonlinear model predictive control optimization problem, the control input sequence u(k) is optimized in a limited prediction time range (N steps) so that the cumulative square sum of the cylinder position tracking error is minimized. The optimization problem can be represented 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 balances the tracking error and the control input size. The setting of the constraint condition is to consider the physical constraint conditions of the system, such as the position, speed and servo valve spool displacement limit.

[0116] 5. Solving control input sequence

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

[0118] 6. Applying control input

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

[0120] 7. Updating state

[0121] The system state is updated, and the actual state after applying the control input is:

[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 nonlinear, time delay and other characteristics of the hydraulic system, the embodiments of the present application propose a control scheme based on nonlinear model predictive control, which directly handles nonlinear constraints in the optimization problem, such as the position range, speed limit and other constraints of the hydraulic cylinder. Make the control meet the physical limitations of the hydraulic system while providing higher control performance. At the same time, the proposed control scheme considers the uncertainty and disturbance of the system in the prediction and optimization process, thereby achieving better robustness. In practical application, it can reduce the influence of external disturbance on the system performance, and ensure the stable operation of the aerial work platform in complex environment.

[0125] The embodiment of the present application also provides a processor configured to execute the method for arm support control in the above embodiment.

[0126] The embodiment of the present application also provides an engineering device, comprising: an arm support; a telescopic oil cylinder and a tilting oil cylinder of the arm support; and the processor in the above embodiment.

[0127] The embodiment of the present application also provides a machine readable storage medium, wherein a program or instruction is stored on the machine readable storage medium, and the program or instruction is executed by a processor to realize the method for arm support control in the above embodiment.

[0128] Those skilled in the art should understand that the embodiment of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can adopt a computer program product in the form of being implemented on one or more computer readable storage media containing computer usable program codes, including but not limited to disk memory, CD-ROM, optical memory, etc.

[0129] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system) and computer program product according to the embodiment of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams and the combination of the flows and / or blocks can be realized by computer program instructions. These computer program instructions can be provided to a general purpose computer, a special purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the computer or other programmable data processing device produce a device for realizing the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one flow or multiple flows and / or blocks Figure 1 The function specified in one flow or multiple flows and / or blocks

[0130] These computer program instructions can also be stored in a computer readable memory capable of guiding the computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer readable memory produce a product including instruction devices, which realize the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one flow or multiple flows and / or blocks Figure 1 The function specified in one flow or multiple flows and / or blocks

[0131] These computer program instructions can also be loaded to the computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to produce a computer implemented process, and the instructions executed on the computer or other programmable device provide a process for realizing the functions specified in the flowcharts and / or block diagrams.Figure 1 one or more processes and / or functions specified in one or more blocks Figure 1 one or more processes and / or functions specified in one or more blocks

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

[0133] Memory can include non-persistent memory and / or volatile memory, random access memory (RAM), and / or non-volatile memory, e.g., read only memory (ROM) or flash memory. Memory is an example of computer readable media.

[0134] Computer readable media includes permanent and non-permanent, removable and non-removable media implemented in any method or technology for storage of information such as 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 disc read only memory (CD-ROM), digital versatile disc (DVD), or other optical storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition herein, computer readable media does not include transitory media, such as modulated data signals and carrier waves.

[0135] It should also be noted that the terms "comprising," "including," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements recited, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0136] The above merely provides an embodiment of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A method for boom control, characterized by, The method is applied to an engineering device including a boom and telescopic and luffing cylinders of the boom, and comprises: acquiring a desired trajectory of a terminal end of the boom; determining a first length of the telescopic cylinder and a second length of the luffing cylinder according to the desired trajectory based on a pre-constructed kinematic model of the terminal end of the boom; determining a deflection deformation variable of the boom according to the second length and a preset luffing cylinder length; correcting the second length of the luffing cylinder according to the deflection deformation variable to obtain a target luffing cylinder length; controlling the terminal end of the boom to work along the desired trajectory based on the first length and the target luffing cylinder length.

2. The method of claim 1, wherein, The controlling the boom to work along the desired trajectory based on the first length and the target luffing cylinder length comprises: constructing a nonlinear dynamics model of a hydraulic cylinder of the boom according to nonlinear characteristics of a hydraulic system of the boom, wherein the nonlinear characteristics include hydraulic pump characteristics, servo characteristics and cylinder friction characteristics; determining a target control parameter of the boom through nonlinear model predictive control according to the first length and the target luffing cylinder length based on the nonlinear dynamics model; controlling the terminal end of the boom to work along the desired trajectory according to the target control parameter.

3. The method of claim 2, wherein, The nonlinear dynamics model satisfies formula (1): Wherein, m is the mass of the load carried by the oil cylinder, x is the length of the oil cylinder, F load is the external force acting on the load, K friction is the friction coefficient of the oil cylinder, A cylinder is the effective area of the oil cylinder; ΔP is the pressure difference between the two ends of the oil cylinder.

4. The method of claim 2, wherein, The determining the target control parameter of the boom through nonlinear model predictive control according to the first length and the target luffing cylinder length based on the nonlinear dynamics model comprises: 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 the nonlinear dynamics model according to the initial state and the initial control amount; determining a cylinder position tracking error corresponding to each prediction time step in combination with measured data of a cylinder position according to the first length and the target luffing cylinder length corresponding to the predicted state of each prediction time step; setting an optimization problem aiming at minimizing a cumulative square sum of the cylinder position tracking errors of each prediction time step; solving the optimization problem through a numerical optimization method based on preset constraint conditions to obtain the target control parameter.

5. The method of claim 1, wherein, The correcting the second length of the luffing cylinder according to the deflection deformation variable to obtain the target luffing cylinder length comprises: determining a desired luffing angle of the luffing cylinder according to the desired trajectory based on the pre-constructed kinematic model of the terminal end of the boom; determining the target luffing cylinder length according to the desired luffing angle, the deflection deformation variable and the second length.

6. The method of claim 5, wherein, The determining the target luffing cylinder length according to the desired luffing angle, the deflection deformation variable and the second length comprises determining the target luffing cylinder length according to formula (2): wherein, is a target pitch cylinder length, l ld is a second length of the pitch cylinder, A is a first preset coefficient, B is a second preset coefficient, φ is a set angle, and Δθ is the deformation amount.

7. The method of claim 1, wherein, The construction method of the kinematic model of the terminal end of the boom comprises: constructing a positive kinematic model of the terminal end of the boom according to a geometric relationship of the boom; determining a trajectory coordinate model of the terminal end of the boom along a spatial curve according to the positive kinematic model of the terminal end of the boom; According to the trajectory coordinate model, the arm support end kinematics model is obtained through an inverse kinematics equation.

8. A processor, comprising: A processor configured to perform the method for arm support control according to any one of claims 1 to 7.

9. An engineering apparatus characterised in that, Comprise: An arm support; Telescopic and luffing cylinders of the arm support; A processor according to claim 8.

10. A machine-readable storage medium having stored thereon a program or instmctions, characterized in that, The program or the instructions are executed by the processor to implement the method for arm support control according to any one of claims 1 to 7.

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