Method for controlling boom, aerial work equipment and machine-readable storage medium

Abstract

This application discloses a method for controlling a boom, an aerial work platform, and a machine-readable storage medium, belonging to the field of engineering machinery technology. The method includes: obtaining the target displacement of the boom's actuators for the next control cycle; the boom's actuators include at least one of a slewing motor, a telescopic cylinder, and a luffing cylinder; determining the target control current of the actuators based on the target displacement, using a pre-built prediction model and preset constraints, wherein the prediction model is used to predict the corresponding displacement based on the input control current; and outputting the target control current of the actuators to the actuators to control the boom's movement. This application can determine the control quantities of each actuator of the boom using a model predictive control method based on a pre-built prediction model and combined with preset constraints, which helps to reduce control errors and improve control stability.

Description

Technical Field

[0001] This application relates to the field of aerial work technology, and more specifically to a method for controlling a boom, aerial work equipment, and a machine-readable storage medium. Background Technology

[0002] Currently, there are two main methods for boom end-point trajectory tracking control: one is closed-loop collaborative control, which uses integrated sensors in the hydraulic system for trajectory tracking; the other is a PID controller that includes feedforward and static deflection compensation. However, because boom end-point position control involves multi-axis linkage control such as turntable rotation, boom luffing, and boom extension, there is strong coupling between the axes, making oscillation problems prone to occur during control. The aforementioned control methods cannot completely avoid these oscillations, resulting in poor boom stability. Therefore, the existing boom end-point control methods suffer from poor stability. Summary of the Invention

[0003] The purpose of this application is to provide a method for controlling a boom, aerial work platform equipment, and machine-readable storage medium to solve the problem of poor stability in the existing boom end control methods.

[0004] To achieve the above objectives, the first aspect of this application provides a method for controlling a boom, the method comprising:

[0005] To obtain the target displacement of the boom actuator in the next control cycle, wherein the boom actuator includes at least one of a slewing motor, a telescopic cylinder, and a luffing cylinder;

[0006] Based on the target displacement, the target control current of the actuator is determined according to the pre-built prediction model and preset constraints. The prediction model is used to predict the corresponding displacement based on the input control current.

[0007] The target control current is output to the actuator to control the boom movement.

[0008] In this embodiment, the target control current of the actuator is determined based on the target displacement, a pre-built prediction model, and preset constraints. This includes: inputting the preset control current of the actuator into the prediction model to obtain the corresponding predicted displacement; determining the displacement error of the actuator based on the predicted displacement and the target displacement; adjusting the preset control current input to the prediction model based on the displacement error until the absolute value of the displacement error of the actuator is less than or equal to the corresponding preset error, and the corresponding system parameters satisfy the preset constraints. The system parameters include the preset control current of the actuator, the total flow rate of the boom's hydraulic system, the length of the boom, the boom's pitch angle, and the boom's slewing angle; and determining the adjusted preset control current as the target control current.

[0009] In this embodiment of the application, the preset constraints include: the preset control current of the actuator is greater than or equal to the corresponding set current; the total flow rate of the boom's hydraulic system is less than the preset flow rate.

[0010] The boom length is within a preset length range; the boom pitch angle is within a first preset angle range; and the boom slewing angle is within a second preset angle range.

[0011] In this embodiment of the application, the method further includes: obtaining the current control current of the actuator of the boom; determining the current change of the actuator based on the current control current and the preset control current; determining the target function value corresponding to the preset control current based on the displacement error of the actuator and the current change, according to the pre-constructed target function; and adjusting the preset control current until the target function value is less than or equal to the preset function value.

[0012] In this embodiment, the preset control current of the actuator is input to the prediction model to obtain the corresponding predicted displacement, including: determining the corresponding proportional valve flow rate based on the preset control current according to the pre-built mapping relationship between the actuator's control current and the proportional valve flow rate; determining the corresponding balance valve flow rate based on the pre-built mapping relationship between the actuator's proportional valve flow rate and the balance valve flow rate; determining the corresponding operating speed based on the pre-built mapping relationship between the actuator's balance valve flow rate and the operating speed; and determining the predicted displacement of the actuator based on the operating speed according to the pre-built mapping relationship between the actuator's operating speed and the displacement.

[0013] In this embodiment of the application, the method further includes: obtaining the actual displacement of the actuator after the boom movement; determining the target predicted displacement of the actuator based on the target control current of the actuator according to the prediction model; determining the prediction error of the actuator based on the actual displacement and the target predicted displacement; and correcting the prediction model based on the prediction error of the actuator.

[0014] In this embodiment of the application, the prediction model is corrected based on the prediction error feedback of the actuator, including: correcting the displacement output by the prediction model based on the prediction error and a preset correction coefficient to obtain the corrected displacement.

[0015] In this embodiment of the application, obtaining the target displacement of the boom actuator in the next control cycle includes: obtaining the current attitude data of the boom and the target attitude data of the next control cycle; and determining the target displacement of the boom actuator based on the current attitude data and the target attitude data.

[0016] The second aspect of this application provides an aerial work platform that uses the above-described method for controlling the boom for boom control.

[0017] A third aspect of this application provides a machine-readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the above-described method for controlling a boom.

[0018] The above technical solution obtains the target displacement of the boom's actuators in the next control cycle. The boom's actuators include at least one of a slewing motor, a telescopic cylinder, and a luffing cylinder. Then, based on the target displacement, a target control current for the actuators is determined using a pre-built predictive model and preset constraints. The predictive model predicts the corresponding displacement based on the input control current. Finally, the target control current is output to the actuators to control the boom's movement. This application can determine the control quantities of each actuator of the boom using a model predictive control method based on a pre-built predictive model and preset constraints, which helps reduce control errors and improve control stability.

[0019] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0021] Figure 1 A flowchart illustrating a method for controlling a boom, provided as an embodiment of this application;

[0022] Figure 2 This is a structural block diagram of a boom end trajectory control device provided in a specific embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0024] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0025] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0026] Figure 1 This is a flowchart illustrating a method for controlling a boom, as provided in an embodiment of this application. Figure 1 As shown in the figure, this application provides a method for controlling a boom. Taking the application of this method to a processor as an example, the method may include the following steps.

[0027] Step S101: Obtain the target displacement of the boom actuator in the next control cycle. The boom actuator includes at least one of a slewing motor, a telescopic cylinder, and a luffing cylinder.

[0028] Step S102: Based on the target displacement, the target control current of the actuator is determined according to the pre-built prediction model and preset constraints. The prediction model is used to predict the corresponding displacement based on the input control current.

[0029] Step S103: Output the target control current of the actuator to the actuator to control the boom movement.

[0030] Specifically, the actuators controlling the boom end effector movement mainly include a slewing motor for controlling boom rotation, telescopic cylinders for controlling the extension of each boom segment, and luffing cylinders for controlling boom luffing. It can be understood that the control process of moving the boom end effector from its current position to a target position can be decomposed into multiple control cycles. The processor can obtain the target displacement of the actuators corresponding to the boom end effector moving from its position in the current control cycle to its position in the next control cycle. In one example, the target displacement may include the slewing displacement of the boom's slewing motor, the cylinder length change of each telescopic cylinder on the boom, and the cylinder length change of each luffing cylinder on the boom.

[0031] It is understandable that traditional boom control methods typically employ PID control. However, considering that boom end-point trajectory tracking is essentially a multi-axis linkage problem involving the entire vehicle, involving at least three axes: turntable rotation, boom luffing, and boom lifting, the coupling between control loops is strong, easily leading to control oscillations and jitters, and making parameter tuning difficult. To ensure the smoothness of the boom control process, this application's embodiment employs a model predictive control strategy to control the boom. Specifically, the target displacement of the boom's actuator is used as a reference trajectory. Based on a pre-built predictive model in the control system and combined with preset constraints, rolling optimization is achieved within the corresponding control cycle, continuously optimizing the control quantity in finite step sizes to determine the target control current corresponding to the boom's actuator. The predictive model is used to predict the corresponding displacement based on the input control current. In one example, the predictive model is constructed based on the actual electrical, hydraulic, and structural relationships of the entire vehicle, and can represent the mathematical relationship between the solenoid valve control current of the actuator and the actuator displacement. The preset constraints are set based on the electromechanical and hydraulic characteristics of the actual system. Thus, compared with PID control, the predictive control method adopted in this application embodiment comprehensively considers how to make the control error smaller and the control smoother when the control current of each control mechanism is given, so as to give the optimal control solution from the current control cycle to the next control cycle, which greatly reduces the control difficulty.

[0032] Finally, the controller can send the target control current of each actuator to the corresponding solenoid valve to adjust the opening of the hydraulic valve port and control the boom movement, so that the boom end moves from the position of the current cycle to the position corresponding to the next cycle.

[0033] The above technical solution obtains the target displacement of the boom's actuators in the next control cycle. The boom's actuators include at least one of a slewing motor, a telescopic cylinder, and a luffing cylinder. Then, based on the target displacement, a target control current for the actuators is determined using a pre-built predictive model and preset constraints. The predictive model predicts the corresponding displacement based on the input control current. Finally, the target control current is output to the actuators to control the boom's movement. This application can determine the control quantities of each actuator of the boom using a model predictive control method based on a pre-built predictive model and preset constraints, which helps reduce control errors and improve control stability.

[0034] In this embodiment of the application, obtaining the target displacement of the boom actuator in the next control cycle includes: obtaining the current attitude data of the boom and the target attitude data of the next control cycle; and determining the target displacement of the boom actuator based on the current attitude data and the target attitude data.

[0035] It can be understood that the control process of moving the boom end effector from its current position to a target position can be decomposed into multiple control cycles. The processor can determine the target displacement of the actuator corresponding to the boom end effector moving from its position in the current control cycle to its position in the next control cycle, based on the boom attitude data corresponding to two adjacent cycles. Specifically, the current attitude data of the boom in the current control cycle and the target attitude data of the boom in the next control cycle are acquired. Based on the boom's geometric structure, the current position of the boom end effector is determined using the current attitude data, and the target position of the boom end effector in the next cycle is determined using the target attitude data. Based on the current position and the next position, the target displacement of each actuator is obtained through trigonometric function transformations. The boom attitude data can be acquired through multiple sensors, such as ultrasonic sensors, millimeter-wave radar sensors, cable sensors, boom tilt sensors, and rotary encoders. The real-time attitude of the boom is calculated by comprehensively analyzing the data collected from each sensor, thus providing a data foundation for subsequent calculations.

[0036] In this embodiment, the target control current of the actuator is determined based on the target displacement, a pre-built prediction model, and preset constraints. This includes: inputting the preset control current of the actuator into the prediction model to obtain the corresponding predicted displacement; determining the displacement error of the actuator based on the predicted displacement and the target displacement; adjusting the preset control current input to the prediction model based on the displacement error until the absolute value of the displacement error of the actuator is less than or equal to the corresponding preset error, and the corresponding system parameters satisfy the preset constraints. The system parameters include the preset control current of the actuator, the total flow rate of the boom's hydraulic system, the length of the boom, the boom's pitch angle, and the boom's slewing angle; and determining the adjusted preset control current as the target control current.

[0037] It is understood that the preset control current can be set according to the actual situation of the vehicle. Preferably, the preset control current of the actuator can be the execution current of the current control cycle. This application adopts an inverse operation method, based on the prediction model and preset constraints, to solve for the target control current of the actuator according to the target displacement of the actuator. Specifically, after inputting the preset control current into the prediction model, the predicted displacement output by the model can be obtained. Then, the difference between the predicted displacement and the target displacement is determined to obtain the displacement error of the actuator under the current preset control current. At the same time, the system parameters corresponding to the predicted control current are determined based on the intermediate quantities generated by the prediction model. The system parameters include the preset control current of the actuator, the total flow rate of the boom's hydraulic system, the length of the boom, the pitch angle of the boom, and the slewing angle of the boom. Further, the absolute value of the displacement error is compared with the magnitude of the preset error, and it is determined whether the system parameters meet the preset constraints.

[0038] In one example, if the absolute value of the displacement error is greater than the preset error and / or the system parameters do not meet the constraints, it indicates that the current preset control current cannot guarantee the stability of the boom control. In this case, the preset control current input to the prediction model can be adjusted according to the displacement error until the absolute value of the displacement error of the actuator is less than or equal to the corresponding preset error, and the corresponding system parameters meet the preset constraints.

[0039] In another example, if the absolute value of the displacement error is less than or equal to the corresponding preset error, and the corresponding system parameters meet the preset constraints, the adjusted preset control current at that moment is determined as the target control current. Thus, by performing a quadratic programming solution based on the prediction function and preset constraints to determine the target control current for each actuator, it is beneficial to improve the smoothness of subsequent boom control.

[0040] In this embodiment of the application, the preset constraints include: the preset control current of the actuator is greater than or equal to the corresponding set current; the total flow rate of the boom's hydraulic system is less than the preset flow rate; the length of the boom is within a preset length range; the pitch angle of the boom is within a first preset angle range; and the slewing angle of the boom is within a second preset angle range.

[0041] Specifically, the embodiments of this application design constraints based on the range of control current variation, the maximum flow rate available from the vehicle's hydraulic system, and the limiting conditions of various mechanical components. The minimum value of the boom retraction current is particularly noteworthy among the control currents. When the boom tilt angle is high, the extension length is long, and the load is heavy, it is necessary to appropriately increase the starting value of the retraction current to avoid strong nonlinear segments and maintain stable control performance. Furthermore, the maximum flow rate available from the hydraulic system is included in the constraints, taking into account the load-sensitive characteristics of the hydraulic system. When the maximum flow rate is insufficient to supply all composite actions, it is distributed according to the load of each hydraulic component. In this case, the electro-hydraulic characteristics will deviate significantly from the calibration curve. During the control process, the required total flow rate should be avoided from exceeding u; the maximum value can be provided. In one example, taking the boom's actuators, including a slewing motor, a telescopic cylinder, and a luffing cylinder, as an example, the preset constraint conditions can be expressed as:

[0042]

[0043] Among them, U min =[u 1min ,u 2min ,u 3min [Set current for each actuator, set current]

[0044] f represents the minimum starting current (per mille) for the corresponding circuit of each actuator; ' 1(k), f ' 2(k) and f ' 3(k) represent the flow rates of the corresponding circuits of each actuator, and their sum is the total flow rate of the hydraulic system, f max The preset flow rate is the maximum flow rate that the hydraulic system can provide; [L] 1min ,L 1max [L represents the preset length range] 1min L is the minimum boom length. 1max [θ is the maximum length of the boom;] 1min ,θ 1max ] represents the first preset angle range, θ 1min θ is the minimum pitch angle of the boom. 1max [θ] represents the maximum pitch angle of the boom; 2min ,θ 2max ] represents the second preset angle range, θ 2min θ is the minimum boom rotation angle. 2max This represents the maximum slewing angle of the boom.

[0045] Thus, the design of constraints is based on the range of control current variation, the maximum flow rate that the vehicle's hydraulic system can provide, and the limiting conditions of each mechanical component. For example, the constraint conditions include a limit on the maximum flow rate that the system can provide, to avoid insufficient flow during the control process and to address the deviation of electro-hydraulic characteristics caused by the load-sensitive characteristics of the hydraulic system.

[0046] In this embodiment of the application, the method further includes: obtaining the current control current of the actuator of the boom; determining the current change of the actuator based on the current control current and the preset control current; determining the target function value corresponding to the preset control current based on the displacement error of the actuator and the current change, according to the pre-constructed target function; and adjusting the preset control current until the target function value is less than or equal to the preset function value.

[0047] It is understandable that the preset function value can be set according to the actual operating conditions of the vehicle or user requirements. To further improve the stability of boom control, the embodiments of this application can design an objective function based on the control error minimization requirements and the electrical, hydraulic, and mechanical characteristics of the actual vehicle. Combining the prediction model, preset constraints, and objective function, a secondary programming solution is performed to obtain the optimal control sequence that minimizes the objective function and simultaneously satisfies all constraints, i.e., the target control flow of each actuator. This control sequence is then sent to the entire vehicle through the controller to achieve smooth control of the boom.

[0048] Specifically, the objective function focuses on minimizing the control error, which is the displacement error. At the same time, the objective function also needs to take into account the change in the control increment, i.e. the change in the current of the actuator. The design here is mainly carried out from three aspects, aiming to maintain the comfort of the driving experience, keep the system energy consumption at a normal or low level, and reduce the impact damage to the hydraulic and mechanical systems of the whole vehicle.

[0049] In one example, taking a boom actuator that includes a slewing motor, a telescopic cylinder, and a luffing cylinder, the objective function can satisfy the following formula:

[0050]

[0051] in, Let ΔU(k+i|k) represent the second norm of the displacement error, and ||ΔU(k+i|k)|| represent the second norm of the current change. Ny represents the prediction time domain, and Nu represents the control time domain. J is the objective function value, Q is the preset displacement error weight matrix, and R is the preset current change weight matrix. For the displacement error of the actuator, To predict the displacement output of the model, Y r (k) represents the target displacement, and ΔU(k) ​​represents the change in current of the actuator.

[0052] Thus, the current change of the actuator is introduced into the objective function, and control oscillations, commutation shocks, energy losses, etc. are considered and added to the composition of the control increment weight matrix. At the same time, the problems of control oscillations and shocks, as well as the small possibility of energy depletion in the system during the control process, are taken into account.

[0053] In this embodiment, the preset control current of the actuator is input to the prediction model to obtain the corresponding predicted displacement, including: determining the corresponding proportional valve flow rate based on the preset control current according to the pre-built mapping relationship between the actuator's control current and the proportional valve flow rate; determining the corresponding balance valve flow rate based on the pre-built mapping relationship between the actuator's proportional valve flow rate and the balance valve flow rate; determining the corresponding operating speed based on the pre-built mapping relationship between the actuator's balance valve flow rate and the operating speed; and determining the predicted displacement of the actuator based on the operating speed according to the pre-built mapping relationship between the actuator's operating speed and the displacement.

[0054] Specifically, the pre-constructed mapping relationship between the control current of the actuator and the flow rate of the proportional valve represents the fundamental electro-hydraulic characteristic relationship of the vehicle control system. In one example, based on existing hydraulic test bench data, the current and flow rate relationship curves of the slewing and boom luffing (telescopic) proportional valves can be linearly fitted to obtain the mapping relationship between the control current of the actuator and the flow rate of the proportional valve. The mapping relationship between the flow rate of the proportional valve and the flow rate of the balance valve represents the nonlinear characteristic of the electro-hydraulic system. Real vehicle tests show that when the boom luffing reaches more than 60 degrees and extends to near the boom extension limit while the control current is relatively small, the relationship between current and flow rate exhibits strong nonlinearity. After studying the composition of the hydraulic system, it was analyzed that this nonlinearity mainly originates from the switching characteristics of the balance valve under negative load conditions. This characteristic is described using a second-order discrete z-domain transfer function to obtain the mapping relationship between the flow rate of the proportional valve and the flow rate of the balance valve. The mapping relationship between the flow rate and operating speed of the balance valve of the actuator is the conversion relationship between the hydraulic flow rate of the balance valve and the movement speed of the cylinder (motor). In one example, the movement speed of the hydraulic component can be calculated from the motor displacement of the rotary motor, the transmission ratio of the rotary mechanism, the cylinder diameter and rod diameter of the telescopic (amplitude) cylinder, etc. Multiplying it by the duration of the control cycle gives the current motor / cylinder displacement increment value, thus obtaining the mapping relationship between the operating speed and displacement of the actuator.

[0055] Thus, by incorporating a fitting process for the nonlinear characteristics of the hydraulic system balance valve into the prediction model to address the nonlinear attitudes of the boom's pitch angle and extension length, the prediction model's ability to describe various system operating conditions is enhanced, providing a solution to the control oscillation problem of ordinary PID control systems under extreme scenarios.

[0056] In this embodiment of the application, the method further includes: obtaining the actual displacement of the actuator after the boom movement; determining the target predicted displacement of the actuator based on the target control current of the actuator according to the prediction model; determining the prediction error of the actuator based on the actual displacement and the target predicted displacement; and correcting the prediction model based on the prediction error of the actuator.

[0057] Specifically, the actual displacement of the actuator after boom movement can be obtained through the vehicle's long-angle sensor, rotary encoder, and other sensors. Simultaneously, based on the final determined control current, the target predicted displacement of the actuator can be determined using a predictive model. Then, the prediction error of the actuator can be determined based on the difference between the actual displacement and the target predicted displacement. Finally, the prediction model is corrected based on the feedback of the actuator's prediction error. Thus, by calibrating the prediction model in the next control cycle based on the actual displacement of the actuator, the prediction model can be optimized, continuously improving its accuracy.

[0058] In this embodiment of the application, the prediction model is corrected based on the prediction error feedback of the actuator, including: correcting the displacement output by the prediction model based on the prediction error and a preset correction coefficient to obtain the corrected displacement.

[0059] Specifically, the preset correction coefficient can be set experimentally. Based on the preset error and the preset correction coefficient, the output value of the prediction model can be corrected in the next control cycle to obtain the corrected displacement. In this way, periodic feedback optimization of the prediction model helps to improve its accuracy.

[0060] Figure 2 This is a structural block diagram of a boom end trajectory control device provided in a specific embodiment of this application. Figure 2 As shown, the end-point trajectory tracking and control is achieved through various hardware devices mounted on the vehicle.

[0061] Hardware devices are mainly divided into four categories according to their functions, including:

[0062] 1. Operating handles and toggle switches. Used to transmit user operating commands to the equipment, switch between normal operating mode and end-point trajectory tracking control mode, and switch trajectory tracking direction, etc.

[0063] 2. Sensors. These include ultrasonic sensors, millimeter-wave radar, boom tilt sensors, draw rope sensors, and rotary encoders, used to acquire the current vehicle attitude and the movement position of the boom end. Specifically, by adding fixtures, ultrasonic sensors can be fixed to the outer surface of the work platform, and millimeter-wave radar can be installed near the boom end. Both types of sensors monitor and record the relative position of the platform and the target object in real time, facilitating timely adjustments to the set trajectory by the control system.

[0064] 3. The vehicle controller is used to send control current signals to the hydraulic solenoid valves based on the received attitude and position information, user commands, etc., and according to the designed control method.

[0065] 4. Hydraulic solenoid valves are used to respond to control signals issued by the controller and drive the turntable slewing mechanism, boom luffing mechanism, and boom telescopic mechanism to operate according to the specified signals.

[0066] In a specific embodiment of this application, the operation process of the control system during boom end-effector trajectory tracking includes the following steps:

[0067] Step 1: Operator toggles the switch to turn on the end-point tracking function, sets the initial stationary position of the boom end as the starting coordinate P0, and determines the tracking direction (up, down, left, right) using the operating handle.

[0068] Step 2: Based on the relative position of the vehicle and the target wall obtained by ranging sensors such as ultrasonic sensors and millimeter-wave radar, as well as the measurement data from the rope sensor, boom tilt sensor, and rotary encoder, the planning layer calculates the real-time attitude of the vehicle and plans the target boom end position P for the current control cycle k. r (k), and using information such as boom length, tilt angle, and slewing angle, the displacement y of the target telescopic cylinder under that cycle is converted through trigonometric function relationships. 1r (k) Displacement of variable amplitude cylinder y 2r (k), displacement of the rotary motor y 3r (k), i.e., Y r (k)=[y 1r (k)y 2r (k)y 3r (k)] T .

[0069] Step 3: Based on the prediction model designed in the control system (the mathematical relationship between the solenoid valve control current and the displacement of the hydraulic actuator), the constraints related to the electromechanical-hydraulic characteristics of the actual system, and the objective function, rolling optimization is implemented in the k-th control cycle. The control quantity (in this scheme, the input current of the corresponding cylinder, motor, and solenoid valve) is continuously optimized within a finite step size, and the predicted performance of the hydraulic actuator displacement under this control quantity is calculated. We select the optimal control current U(k) = [u1(k)u2(k)u3(k)] that minimizes the control error and satisfies all constraints. T If the conditions cannot be fully met, the current suboptimal solution will be selected.

[0070] Step 4: The controller sends the optimal control current to the corresponding solenoid valve, adjusts the opening of the hydraulic valve, acquires real-time data from the sensors on the bus, and calculates and converts the actual telescopic (amplitude-changing) cylinder extension and slewing motor rotation angle Y(k) = [y1(k)y2(k)y3(k)]. T .

[0071] Step 5: Calculate the output value Y(k) of the hydraulic actuator in the real system and the output value of the prediction model. The difference is compensated in the update of the model's state variables in the next control cycle to correct the model prediction error caused by model mismatch or environmental disturbance.

[0072] Step 6: If the operator does not issue a command to terminate end trajectory tracking, the process continues from step 2. If a termination command is issued, the control process ends.

[0073] In summary, this solution introduces a strong nonlinear element caused by hydraulic components into the prediction model, resulting in a stronger overall control strategy capable of handling nonlinearities. This addresses the issue of poor driving experience caused by PID control jitter under extreme operating conditions. The objective function considers minimizing control oscillations, shocks, and energy losses, optimizing the composition of the control increment weight matrix to prioritize low-energy control sequences while maintaining control stability. Furthermore, the constraint condition includes a limit on the system's maximum available flow rate, keeping the control sequence within the system's normal capacity boundaries. In contrast, achieving the same effect using a PID control loop requires extensive and complex programming after the main PID module to compensate for the inherent limitations of PID control. Therefore, compared to traditional PID control, the embodiments of this application significantly reduce control difficulty and achieve higher boom control stability.

[0074] This application also provides an aerial work platform configured to perform the method for controlling the boom described in the above embodiments.

[0075] This application also provides a machine-readable storage medium storing a program or instructions, which, when executed by a processor, implement the method for controlling the boom described above.

[0076] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0077] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0078] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0079] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0080] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0081] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0082] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, 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 technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0083] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0084] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for controlling a boom, characterized in that, The method includes: The target displacement of the boom actuator is obtained in the next control cycle. The boom actuator includes at least one of a slewing motor, a telescopic cylinder, and a luffing cylinder. Based on the target displacement, and using a pre-built prediction model and preset constraints, the target control current of the actuator is determined, wherein the prediction model is used to predict the corresponding displacement based on the input control current. The target control current of the actuator is output to the actuator to control the boom movement; The step of determining the target control current of the actuator based on the target displacement, using a pre-built prediction model and preset constraints, includes: The preset control current of the actuator is input to the prediction model to obtain the corresponding predicted displacement. The displacement error of the actuator is determined based on the predicted displacement and the target displacement. The preset control current input to the prediction model is adjusted according to the displacement error until the absolute value of the displacement error of the actuator is less than or equal to the corresponding preset error, and the corresponding system parameters satisfy the preset constraint conditions. The system parameters include the preset control current of the actuator, the total flow rate of the hydraulic system of the boom, the length of the boom, the pitch angle of the boom, and the slewing angle of the boom. The adjusted preset control current is determined as the target control current.

2. The method according to claim 1, characterized in that, The preset constraints include: The preset control current of the actuator is greater than or equal to the corresponding set current; The total flow rate of the boom's hydraulic system is less than the preset flow rate; The length of the boom is within a preset length range; The boom's pitch angle is within a first preset angle range; and The slewing angle of the boom is within the second preset angle range.

3. The method according to claim 1, characterized in that, The method further includes: Obtain the current control current of the actuator of the boom; The current change of the actuator is determined based on the current control current and the preset control current; Based on the pre-constructed objective function, the objective function value corresponding to the preset control current is determined according to the displacement error and current change of the actuator; Adjust the preset control current until the target function value is less than or equal to the preset function value.

4. The method according to claim 1, characterized in that, The step of inputting a preset control current of the actuator into the prediction model to obtain the corresponding predicted displacement includes: Based on the pre-built mapping relationship between the control current of the actuator and the proportional valve flow rate, the corresponding proportional valve flow rate is determined according to the preset control current. Based on the pre-built mapping relationship between the proportional valve flow rate and the balancing valve flow rate of the actuator, the corresponding balancing valve flow rate is determined according to the proportional valve flow rate; Based on the pre-built mapping relationship between the balance valve flow rate and the operating speed of the actuator, the corresponding operating speed is determined according to the balance valve flow rate; Based on the pre-built mapping relationship between the operating speed and displacement of the actuator, the predicted displacement of the actuator is determined according to the operating speed.

5. The method according to claim 1, characterized in that, The method further includes: Obtain the actual displacement of the actuator after the boom movement; Based on the prediction model, the target predicted displacement of the actuator is determined according to the target control current of the actuator. The prediction error of the actuator is determined based on the actual displacement and the target predicted displacement. The prediction model is corrected based on the prediction error feedback from the actuator.

6. The method according to claim 5, characterized in that, The step of correcting the prediction model based on the prediction error feedback of the actuator includes: Based on the prediction error and the preset correction coefficient, the displacement output by the prediction model is corrected to obtain the corrected displacement.

7. The method according to claim 1, characterized in that, The process of obtaining the target displacement of the boom actuator in the next control cycle includes: Obtain the current attitude data of the boom and the target attitude data for the next control cycle; The target displacement of the actuator of the boom is determined based on the current attitude data and the target attitude data.

8. A high-altitude work equipment, characterized in that, Boom control is performed using the method for controlling the boom according to any one of claims 1 to 7.

9. A machine-readable storage medium on which a program or instructions are stored, characterized in that, When the program or the instructions are executed by the processor, they implement the method for controlling the boom according to any one of claims 1 to 7.

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