Six-degree-of-freedom tower crane anti-swing control method and system based on sliding mode control

Abstract

The invention relates to the technical field of tower crane anti-swing motion control, in particular to a six-degree-of-freedom tower crane anti-swing control method and system based on sliding mode control. Building a tower crane dynamic model based on a Lagrange method; linearizing the tower crane at a balance position by using the constructed dynamic model of the tower crane; designing a sub-sliding mode surface according to the state information of the tower crane and the selected error signal, and designing a preliminary control law by utilizing a principle that the change rate of a Lyapunov function is negative; estimating unknown disturbance and model uncertainty by using an adaptive algorithm to obtain an updated control law; designing a total sliding mode surface, introducing an auxiliary function, and selecting a proper reaching law to solve an auxiliary control law; and combining the updated control law with the auxiliary control law to obtain a final control law. Through the method of constructing the layered sliding mode surface and introducing the self-adaptive algorithm, the problem that the tower crane is easily interfered in a complex environment is effectively solved, and the working efficiency and the performance of the tower crane are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of anti-sway motion control of tower cranes, in particular to a six-degree-of-freedom tower crane anti-sway control method and system based on sliding mode control. Background Art

[0002] As we all know, cranes play an increasingly important role in our daily lives and are used in more and more occasions. Due to the complex working environment of cranes, they are often affected by various external disturbances and model uncertainties. How to ensure the working efficiency and safety of cranes in a complex environment is one of the primary considerations. Therefore, by using the dynamic model of tower cranes, according to the designed adaptive rate and backstepping hierarchical sliding mode control law, a good control effect of tower cranes can be achieved.

[0003] Traditional crane control methods, such as PID control and LQR control, have some limitations when dealing with crane control problems in complex environments:

[0004] Insufficient adaptability to external disturbances: Traditional control methods are unable to effectively respond to external disturbances such as wind and load changes, which can easily lead to an increase in the swing amplitude of the crane, affecting work efficiency and safety.

[0005] Model uncertainty problem: In actual work, the parameters of the crane (such as mass, friction coefficient, etc.) may deviate from the theoretical model, and traditional control methods are difficult to accurately compensate for these uncertainties.

[0006] Underactuated problem: Tower cranes are usually an underactuated submodule, that is, the number of control inputs is less than the module degrees of freedom, which brings challenges to the control design. Traditional methods are difficult to effectively control all degrees of freedom.

[0007] Nonlinear characteristics: Crane units have strong nonlinear characteristics, and traditional linear control methods have limited effectiveness in dealing with such units.

[0008] Multi-degree-of-freedom coupling problem: There is a complex coupling relationship between the degrees of freedom of a six-degree-of-freedom tower crane, and traditional methods are difficult to take into account the control of multiple degrees of freedom at the same time.

[0009] In response to these problems, researchers have proposed some improved methods, such as fuzzy control, neural network control, etc. However, these methods still have some shortcomings, such as high computational complexity, lack of real-time performance, and strong dependence on expert experience.

[0010] Therefore, there is an urgent need for a control method that can effectively deal with complex environments, model uncertainty and underactuation problems, and has good real-time and robustness. The six-degree-of-freedom tower crane anti-sway control method based on sliding mode control proposed in this invention effectively solves the above problems by utilizing the dynamic model of the tower crane, combining adaptive law and hierarchical sliding mode control. Summary of the invention

[0011] In view of the problems existing in the prior art, the present invention is proposed.

[0012] Therefore, the problem to be solved by the present invention is how to solve the problem that most cranes are affected by various unknown external interferences and model uncertainties when working.

[0013] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0014] In a first aspect, an embodiment of the present invention provides a six-degree-of-freedom tower crane anti-sway control method based on sliding mode control, which includes: using the real-time data of the tower crane to make a difference with the expected position to construct an error signal;

[0015] Using the error signal, the corresponding sub-sliding surfaces and Lyapunov functions are designed to obtain the control laws of the two sub-modules.

[0016] Based on the previous step, the adaptive law is used to estimate the disturbance and uncertainty of the dynamic model unit, and the overall sliding surface is designed to obtain the auxiliary control law;

[0017] The control laws of the two submodules are combined with the auxiliary control law to obtain the final control law.

[0018] As a preferred solution of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control of the present invention, wherein: the dynamic model of the tower crane is first constructed and then linearized based on the difference between the real-time data of the tower crane and the expected position;

[0019] The dynamic model of the tower crane is linearized at the equilibrium position and expressed as:

[0020]

[0021] Among them, M t is the mass of the car, m 1 is the mass of the hook, m 2 is the mass of the load, l 1 is the length of the rope between the trolley and the hook, l 2 is the rope length between the hook and the load, x is the trolley position, α is the cantilever rotation angle, θ 1 and θ 2are the angles of the hook projected onto the vertical plane parallel to the boom and onto the vertical plane perpendicular to the boom, θ 3 and θ 4 are the angles of the load projected onto the vertical plane parallel to the boom and onto the vertical plane perpendicular to the boom, J 0 is the moment of inertia in the direction of rotation, u 1 is the driving force in the cantilever direction, τ 1 is the disturbance in the cantilever direction, u 2 is the driving force in the direction of the car, τ 2 is the disturbance of the car's direction.

[0022] As a preferred solution of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control of the present invention, wherein: according to the linearized dynamic model of the tower crane, its dynamic model unit is divided into a driving submodule and an under-actuated submodule:

[0023]

[0024] x 1 =q a =[αx] T ,

[0025] x 3 =q u =[θ 1 θ 2 θ 3 θ 3 ] T ,

[0026]

[0027] Among them, M(q) is the inertia matrix, G(q) is the gravity matrix, and U = [u 1 ,u 2 ] T is the input torque,

[0028] τ=[τ 1 ,τ 2 ] T It is an unknown disturbance.

[0029] As a preferred solution of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control of the present invention, wherein: the real-time state quantity of the tower crane model is subtracted from the expected value to construct an error signal, and then the corresponding sub-sliding surface is designed:

[0030]

[0031] Among them, x1d and x 3d Represents x 1 and x 2 The target position, α 1 and α 2 is an auxiliary function, c 1 , c 2 , k 1 ,k 2 is the parameter, δ 1 and δ 2 is the designed sliding surface;

[0032] The preliminary feedback control law designed according to the sliding surface is:

[0033]

[0034] where h 1 ,h 2 ,w 1 ,w 2 For the corresponding parameters.

[0035] As a preferred solution of the anti-sway control method of a six-degree-of-freedom tower crane based on sliding mode control of the present invention, wherein: based on the previous step, the disturbance and uncertainty of the dynamic model unit are estimated by using the adaptive law, and the adaptive algorithm is used to further estimate it, and the definition is F 1 ,F 2 The estimated value of is, and the estimated error is Define the adaptive law and obtain the updated control law:

[0036]

[0037] in is the adaptive law, r 1 ,r 2 as a parameter.

[0038] As a preferred solution of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control of the present invention, wherein: the control law based on obtaining two submodules;

[0039] While ensuring the stability of the submodules, define the total sliding surface and introduce the auxiliary control law:

[0040] δ=a 1 δ 1 +a 2 δ 2

[0041] u t =u 1 +u 2 +usw

[0042] where a 1 ,a 2 is the corresponding parameter of the sub-sliding surface, u sw is the auxiliary control law introduced.

[0043] As a preferred solution of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control of the present invention, wherein: the method based on using the total sliding mode surface and the known control law Find the auxiliary control law And thus the final control law is obtained:

[0044]

[0045] The crane is analyzed based on the adaptive law and layered sliding mode, and compared with the traditional double-swing tower crane control method;

[0046] When the positioning distance and the cantilever positioning distance are constant, the angle θ on the vertical plane parallel to the cantilever is obtained according to the coordinate transformation projection of the coordinate system. 1 ,θ 3 and the angle θ projected onto the vertical plane perpendicular to the cantilever 2 ,θ 4 The amplitude of the swing angle is used to determine the swing angle suppression effect.

[0047] In a second aspect, an embodiment of the present invention provides a six-degree-of-freedom tower crane anti-sway control system based on sliding mode control, which includes:

[0048] In a third aspect, an embodiment of the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program instructions are executed by the processor, the steps of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control as described in the first aspect of the present invention are implemented.

[0049] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program instructions are executed by a processor, the steps of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control as described in the first aspect of the present invention are implemented.

[0050] The invention has the following beneficial effects: the dynamic model unit is divided into two submodules for analysis, and the overall control law is designed by using the idea of ​​layered sliding mode, so as to realize the control of the under-actuated part. In addition, the adaptive algorithm is used to eliminate the influence of disturbance and model unknown, so as to ensure the working efficiency and safety of the crane in a complex working environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 It is a flow chart of the anti-sway control method of six-degree-of-freedom tower crane based on sliding mode control;

[0053] Figure 2 It is a computer equipment diagram of the anti-sway control method of a six-degree-of-freedom tower crane based on sliding mode control;

[0054] Figure 3 The structural principle diagram of a tower crane is a six-degree-of-freedom tower crane anti-sway control method based on sliding mode control;

[0055] Figure 4 It is a flow chart of the anti-sway control method of a six-degree-of-freedom tower crane based on sliding mode control;

[0056] Figure 5 It is the logic diagram of the simulation platform encoder of the anti-sway control method of the six-degree-of-freedom tower crane based on sliding mode control;

[0057] Figure 6 This is a diagram showing the simulation results of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control and the traditional LQR control method. DETAILED DESCRIPTION

[0058] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0059] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0060] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0061] Example 1

[0062] Reference Figure 1-2, which is the first embodiment of the present invention, provides a six-degree-of-freedom tower crane anti-sway control method based on sliding mode control, comprising:

[0063] S100: using the real-time data of the tower crane to make a difference with the expected position, and constructing an error signal;

[0064] S101: Construct a dynamic model of a tower crane based on the Lagrangian method; the dynamic model of the tower crane is expressed as:

[0065]

[0066]

[0067] Among them, M t is the mass of the car, m 1 is the mass of the hook, m 2 is the mass of the load, l 1 is the length of the rope between the trolley and the hook, l 2 is the rope length between the hook and the load, x is the trolley position, α is the cantilever rotation angle, cosθ i and sinθ i Use C i and S i Indicates that θ 1 and θ 2 are the angles of the hook projected onto the vertical plane parallel to the boom and onto the vertical plane perpendicular to the boom, θ 3 and θ 4 are the angles of the load projected onto the vertical plane parallel to the boom and onto the vertical plane perpendicular to the boom, J 0 is the moment of inertia in the direction of rotation, u 1 is the driving force in the cantilever direction, τ 1 is the disturbance in the cantilever direction, u 2 is the driving force in the direction of the car, τ 2 is the disturbance of the car's direction.

[0068] The established dynamic model of tower crane takes into account the characteristics such as the moment of inertia of the load in actual applications, and its nonlinear characteristics are fully consistent with the actual crane.

[0069] S102: The dynamic model of the tower crane constructed is linearized at the equilibrium position. The dynamic model of the tower crane is linearized at the equilibrium position and expressed as:

[0070]

[0071] Among them, M t is the mass of the car, m 1 is the mass of the hook, m2 is the mass of the load, l 1 is the length of the rope between the trolley and the hook, l 2 is the rope length between the hook and the load, x is the trolley position, α is the cantilever rotation angle, θ 1 and θ 2 are the angles of the hook projected onto the vertical plane parallel to the boom and onto the vertical plane perpendicular to the boom, θ 3 and θ 4 are the angles of the load projected onto the vertical plane parallel to the boom and onto the vertical plane perpendicular to the boom, J 0 is the moment of inertia in the direction of rotation, u 1 is the driving force in the cantilever direction, τ 1 is the disturbance in the cantilever direction, u 2 is the driving force in the direction of the car, τ 2 is the disturbance of the car's direction.

[0072] S200: Using the error signal, design the corresponding sub-sliding surface and Lyapunov function to find the control law of the two sub-modules;

[0073] S201: According to the linearized dynamic model of the tower crane, the dynamic model unit is divided into a driving submodule and an under-actuated submodule:

[0074]

[0075] x 1 =q a =[αx] T ,

[0076] x 3 =q u =[θ 1 θ 2 θ 3 θ 3 ] T ,

[0077]

[0078] Among them, M(q) is the inertia matrix, G(q) is the gravity matrix, and U = [u 1 ,u 2 ] T is the input torque,

[0079] τ=[τ 1 ,τ 2 ] T It is an unknown disturbance.

[0080] Preferably, according to the constructed submodule form, an error signal and a sub-sliding surface are defined;

[0081] S202: Subtract the real-time state quantity of the tower crane model from the expected value, construct an error signal, and then design the corresponding sub-sliding surface:

[0082]

[0083] Among them, x 1d and x 3d Represents x 1 and x 2 The target position, α 1 and α 2 is an auxiliary function, c 1 , c 2 , k 1 ,k 2 is the parameter, δ 1 and δ 2 is the designed sliding surface;

[0084] The preliminary feedback control law designed according to the sliding surface is:

[0085]

[0086] where h 1 ,h 2 ,w 1 ,w 2 For the corresponding parameters.

[0087] S300: Based on the previous step, the adaptive law is used to estimate the disturbance and uncertainty of the dynamic model unit, and the overall sliding surface is designed to obtain the auxiliary control law;

[0088] Preferably, the control laws corresponding to the sub-modules are calculated respectively according to the two designed sub-sliding surfaces; the disturbance and model uncertainty are estimated according to the adaptive algorithm;

[0089] Furthermore, the adaptive algorithm estimation process is expressed as:

[0090]

[0091] in is an estimated value, is the estimation error, It is an adaptive law.

[0092] S301: Based on the adaptive law used in the previous step to estimate the disturbance and uncertainty of the dynamic model unit, an adaptive algorithm is used to further estimate it, and define F 1 ,F 2The estimated value of is, and the estimated error is Define the adaptive law and obtain the updated control law:

[0093]

[0094] in is the adaptive law, r 1 ,r 2 as a parameter.

[0095] S400: Combining the control laws of the two submodules with the auxiliary control law to obtain a final control law.

[0096] S401: Finding the control law of the two submodules;

[0097] While ensuring the stability of the submodules, define the total sliding surface and introduce the auxiliary control law:

[0098] δ=a 1 δ 1 +a 2 δ 2

[0099] u t =u 1 +u 2 +u sw

[0100] where a 1 ,a 2 is the corresponding parameter of the sub-sliding surface, u sw is the auxiliary control law introduced.

[0101] Preferably, constructing a total sliding surface and an auxiliary control law;

[0102] Furthermore, the overall sliding surface and auxiliary control law are constructed as follows:

[0103] δ=a 1 δ 1 +a 2 δ 2

[0104] u t =u 1 +u 2 +u sw

[0105] where a 1 ,a 2 is the corresponding parameter of the sub-sliding surface, u sw is the auxiliary control law introduced.

[0106] S402: Based on the use of the total sliding surface and the known control law Find the auxiliary control law And thus the final control law is obtained:

[0107]

[0108] The crane is analyzed based on the adaptive law and layered sliding mode, and compared with the traditional double-swing tower crane control method;

[0109] When the positioning distance and the cantilever positioning distance are constant, the angle θ on the vertical plane parallel to the cantilever is obtained according to the coordinate transformation projection of the coordinate system. 1 ,θ 3 and the angle θ projected onto the vertical plane perpendicular to the cantilever 2 ,θ 4 The amplitude of the swing angle is used to determine the swing angle suppression effect.

[0110] It should be noted that the control law combining the adaptive algorithm and the hierarchical sliding mode control method effectively eliminates the influence of external unknown disturbances and model uncertainty on the operation of the tower crane, ensuring the working efficiency and safety of the tower crane in a complex working environment.

[0111] Furthermore, this embodiment also provides a six-degree-of-freedom tower crane anti-sway control system based on sliding mode control, comprising:

[0112] The building module uses the real-time data of the tower crane to make a difference with the expected position and construct an error signal;

[0113] The calculation module uses the error signal to design the corresponding sub-sliding surface and Lyapunov function to obtain the control law of the two sub-modules;

[0114] Iterative module, based on the previous step, uses adaptive law to estimate the disturbance and uncertainty of the dynamic model unit and designs the overall sliding surface to obtain the auxiliary control law;

[0115] The output module combines the control laws of the two submodules with the auxiliary control law to obtain the final control law.

[0116] This embodiment also provides a computer device, which is suitable for the anti-sway control method of a six-degree-of-freedom tower crane based on sliding mode control, including a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the anti-sway control method of a six-degree-of-freedom tower crane based on sliding mode control as proposed in the above embodiment.

[0117] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0118] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, the anti-sway control method for a six-degree-of-freedom tower crane based on sliding mode control as proposed in the above embodiment is implemented.

[0119] In summary, by constructing a dynamic model of a tower crane based on the Lagrangian method, an accurate description of the complex six-degree-of-freedom dynamic model unit is achieved. This method takes into account the characteristics of the load's moment of inertia in actual applications, making the model closer to the nonlinear characteristics of the actual crane, providing a reliable theoretical basis for subsequent control design, and helping to improve control accuracy and the stability of the dynamic model unit.

[0120] By linearizing the tower crane dynamic model at the equilibrium position, the complex nonlinear dynamic model unit is simplified. This step reduces the complexity of the controller design while retaining the key dynamic characteristics of the dynamic model unit, making the subsequent sliding mode control design more convenient and efficient, which is conducive to improving the real-time performance of the controller.

[0121] By dividing the dynamic model unit into actuated submodules and underactuated submodules and designing corresponding sub-sliding surfaces, effective control of the underactuated submodules is achieved. This hierarchical control strategy not only solves the underactuated problem that is difficult to handle with traditional control methods, but also improves the control accuracy and robustness of the dynamic model unit, making it possible to fully control a six-degree-of-freedom tower crane.

[0122] By introducing adaptive laws to estimate the disturbance and uncertainty of the dynamic model unit, real-time compensation for external interference and model errors is achieved. This method significantly improves the anti-interference ability and adaptability of the dynamic model unit, enabling the controller to maintain good performance in complex and changing environments, greatly improving the working efficiency and safety of tower cranes.

[0123] By designing the overall sliding surface and introducing the auxiliary control law, the coordinated control of multiple degrees of freedom is achieved. This design not only takes into account the stability of each submodule, but also takes into account the performance of the overall dynamic model unit, effectively solves the coupling problem between multiple degrees of freedom, and improves the overall control effect of the dynamic model unit.

[0124] By combining the control laws of the two submodules with the auxiliary control law, the final control law is obtained, which realizes the unified control of the complex six-degree-of-freedom dynamic model unit. This comprehensive control strategy not only ensures the stability of each submodule, but also realizes the optimal control of the overall dynamic model unit, significantly improving the positioning accuracy and anti-sway effect of the tower crane.

[0125] Through experimental verification, this method has shown obvious advantages in terms of cantilever positioning time, trolley positioning time and maximum swing angle at each angle. Especially in the presence of external unknown disturbances and model uncertainty, this method can still achieve smooth and accurate positioning and effective swing angle suppression, which is difficult to achieve with traditional LQR controllers and ESC controllers.

[0126] In summary, the anti-sway control method and system for a six-degree-of-freedom tower crane based on sliding mode control proposed in the present invention effectively solves the control problem of a tower crane in a complex environment through an innovative control strategy design. It not only overcomes the shortcomings of traditional methods in dealing with under-actuated dynamic model units, nonlinear characteristics and external interference, but also realizes coordinated control of multiple degrees of freedom. This method has achieved remarkable results in improving control accuracy, enhancing the robustness of dynamic model units and improving overall performance, providing a strong guarantee for the safe and efficient operation of tower cranes in complex working environments, and has important theoretical significance and practical application value.

[0127] Example 2

[0128] Reference Figure 2-Figure 6 , which is the second embodiment of the present invention, provides a six-degree-of-freedom tower crane anti-sway control method based on sliding mode control. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0129] A tower crane hardware simulation platform was built based on the actual working state of the crane, which consists of a motion control board, an industrial computer, a crane, and a host computer. Combined with the internal logic of the simulation platform encoder, such as Figure 3As shown, an embodiment of the present invention utilizes four absolute encoders, including a hook angle encoder 100, a load angle encoder 101, a displacement encoder 102, and a cantilever rotation angle encoder 103, to measure in real time the angle between the hook and the load, the displacement between the trolley and the guide rail, and the cantilever rotation angle. For the drive units 104 and 105, the present invention uses an absolute encoder for feedback of the trolley displacement and an encoder for feedback of the cantilever rotation angle.

[0130] The data interaction of the constructed platform is completed by a motion control board 106 and an industrial computer 107. The data measured by the three encoders are input into the motion control board 106, and then transmitted to the industrial computer 107 through the motion control board 106. The feedback data is integrated and processed by the MATLAB simulation module on the industrial computer 107 end, with a sampling period of 0.005s to form a real-time control signal. The motion control board 106 feeds back the generated signal to the drive units 104 and 105 to drive the crane movement.

[0131] Parameter settings:

[0132] k 1 =diag(0.15,0.15),k2=diag(0.35,0.35,0.35,0.35),c 1 =diag(0.42,0.42),

[0133] c 2 =diag(24.7,24.7,24.7,24.7),h 1 =diag(10,10),w 1 =diag(10,10),

[0134] h 2 =diag(20,20,20,20),w 2 =diag(20,20,20,20),

[0135] r 1 =diag(25,25),r 2 =diag(30,30,30,30),

[0136]

[0137] The conventional LQR controller, ESC controller and the controller using this control method were compared in the experiment. The control formula of the conventional LQR controller is:

[0138]

[0139] Among them, k ij is the parameter, e i is the error signal.

[0140] The control formula of the ESC controller is:

[0141]

[0142] in:

[0143]

[0144] It should be noted that, in order to ensure the fairness of the experimental verification, the parameter values ​​adopted by the comparison controller are kept consistent with the parameter values ​​of the present invention.

[0145] The amplitudes of the method used in this method and the method used in the traditional backstepping controller are calculated using the experimental platform constructed above, and the comparison results are shown in Table 1:

[0146] Table 1 Effect comparison

[0147]

[0148]

[0149] Also refer to Figure 6 It can be seen that when there are external unknown disturbances and model uncertainties, the traditional LQR controller and ESC controller can achieve positioning effects, but the positioning process is not smooth enough and is prone to overshoot. In addition, the swing suppression effect of the four swing angles is not good, and the angle swing amplitude is large. The controller proposed by the present invention can not only smoothly achieve accurate positioning, but also effectively suppress the swing of the swing angle.

[0150] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A six-degree-of-freedom tower crane anti-sway control method based on sliding mode control, characterized in that: include, The error signal is constructed by subtracting the real-time data of the tower crane from the expected position; Using the error signal, the corresponding sub-sliding surfaces and Lyapunov functions are designed to obtain the control laws of the two sub-modules. Based on the previous step, the adaptive law is used to estimate the disturbance and uncertainty of the dynamic model unit, and the overall sliding surface is designed to obtain the auxiliary control law; The control laws of the two submodules are combined with the auxiliary control law to obtain the final control law.

2. The anti-sway control method for a six-degree-of-freedom tower crane based on sliding mode control according to claim 1, characterized in that: The method is based on subtracting the real-time data of the tower crane from the expected position, first constructing a dynamic model of the tower crane and then performing linearization processing; The dynamic model of the tower crane is linearized at the equilibrium position and expressed as: Among them, M t is the mass of the trolley, m1 is the mass of the hook, m2 is the mass of the load, l1 is the rope length between the trolley and the hook, l2 is the rope length between the hook and the load, x is the trolley positioning, α is the cantilever rotation angle, θ1 and θ2 are the angles of the hook projected onto the vertical plane parallel to the boom and the vertical plane perpendicular to the cantilever, θ3 and θ4 are the angles of the load projected onto the vertical plane parallel to the boom and the vertical plane perpendicular to the cantilever, J0 is the moment of inertia in the rotation direction, u1 is the driving force in the cantilever direction, τ1 is the disturbance in the cantilever direction, u2 is the driving force in the trolley direction, τ2 is the disturbance in the trolley direction.

3. The anti-sway control method for a six-degree-of-freedom tower crane based on sliding mode control as claimed in claim 2, characterized in that: According to the linearized dynamic model of the tower crane, its dynamic model unit is divided into a driving submodule and an under-actuated submodule: Among them, M(q) is the inertia matrix, G(q) is the gravity matrix, and U=[u1,u2] T is the input torque, τ=[τ1,τ2] T It is an unknown disturbance.

4. The anti-sway control method for a six-degree-of-freedom tower crane based on sliding mode control as claimed in claim 3, characterized in that: The real-time state quantity of the tower crane model is subtracted from the expected value to construct an error signal, and then the corresponding sub-sliding surface is designed: Among them, x 1d and x 3d represents the target position of x1 and x2, α1 and α2 are auxiliary functions, c1, c2, k1, k2 are parameters, δ1 and δ2 are the designed sliding surfaces; The preliminary feedback control law designed according to the sliding surface is: Among them, h1, h2, w1, w2 are corresponding parameters.

5. The anti-sway control method for a six-degree-of-freedom tower crane based on sliding mode control as claimed in claim 4, characterized in that: Based on the previous step, the adaptive law is used to estimate the disturbance and uncertainty of the dynamic model unit, and the adaptive algorithm is used to further estimate it. Define is the estimated value of F1 and F2, and the estimated error is Define the adaptive law and obtain the updated control law: in is the adaptive law, r1 and r2 are parameters.

6. The anti-sway control method for a six-degree-of-freedom tower crane based on sliding mode control as claimed in claim 5, characterized in that: The control law based on finding the two submodules; While ensuring the stability of the submodules, define the total sliding surface and introduce the auxiliary control law: δ=a1δ1+a2δ2 u t =u1+u2+u sw Where a1, a2 are the corresponding parameters of the sub-sliding surface, u sw is the auxiliary control law introduced.

7. The anti-sway control method for a six-degree-of-freedom tower crane based on sliding mode control as claimed in claim 6, characterized in that: The control law based on the total sliding surface and the known Find the auxiliary control law And thus the final control law is obtained: The crane is analyzed based on the adaptive law and layered sliding mode, and compared with the traditional double-swing tower crane control method; When the positioning distance and the cantilever positioning distance are constant, the amplitudes of the angles θ1, θ3 on the vertical plane parallel to the boom and the angles θ2, θ4 projected on the vertical plane perpendicular to the cantilever are obtained according to the coordinate transformation projection of the coordinate system to judge the swing angle suppression effect.

8. A six-degree-of-freedom tower crane anti-sway control system based on sliding mode control, based on the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control according to any one of claims 1 to 7, characterized in that: Also includes, The building module uses the real-time data of the tower crane to make a difference with the expected position and construct an error signal; The calculation module uses the error signal to design the corresponding sub-sliding surface and Lyapunov function to obtain the control law of the two sub-modules; Iterative module, based on the previous step, uses adaptive law to estimate the disturbance and uncertainty of the dynamic model unit and designs the overall sliding surface to obtain the auxiliary control law; The output module combines the control laws of the two submodules with the auxiliary control law to obtain the final control law.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control are implemented as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the six-degree-of-freedom tower crane anti-sway control method based on sliding mode control are implemented as described in any one of claims 1 to 7.

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