Method for eliminating redundant force fighting of statically indeterminate system

Abstract

The invention discloses a method for eliminating redundant force fighting of a statically indeterminate system, and relates to the technical field of automatic control. The problems that a control system is poor in precision, large in noise, small in static output and the like caused by redundant force fighting in an existing statically indeterminate system are solved. The method comprises the following steps: constructing a statically indeterminate system, wherein the statically indeterminate system comprises a conventional rigid body position ring and a redundant force control ring; acquiring rigid body posture decomposition factors according to a statically indeterminate system; calculating a rigid body posture synthesis factor according to the rigid body posture decomposition factor; calculating a deformation pose decomposition factor according to the rigid pose synthesis factor; generating a position correction control signal according to the redundant force controller and the deformation pose decomposition factor; generating a control signal of a position loop according to the position and posture controller and the rigid position and posture decomposition factor; and superposing the position correction control signal and the position loop control signal as an input signal excitation system to complete redundant force fighting elimination. The method is applied to control of a statically indeterminate system in ground test equipment in the fields of traffic, spaceflight, civil engineering and the like.

Description

Technical Field

[0001] The invention relates to the field of automatic control technology, and in particular to a method for eliminating redundant force disputes in a hyperstatic system. Background Art

[0002] Electromechanical systems are often widely used in the control loops of some typical equipment, especially in complex test equipment with heavy loads, high test index requirements, and large load masses. Since these equipment require high-precision control and multi-position motion, a single servo actuator often cannot meet the needs of precise control of multiple positions and complex paths. Therefore, in order to ensure that the system can achieve multiple different positions, it is usually necessary to configure multiple servo actuators at each position, so that the entire test equipment adopts a hyperstatic structure.

[0003] In this structure, the number of driven actuators far exceeds the number of postures actually required, causing the system to exhibit over-constrained characteristics. The number of these redundant actuators is actually the difference between the number of actuators and the number of achieved postures. The core challenge of this design is that although the number of actuators in the system exceeds the actual demand, if the motion accuracy of these actuators is inconsistent, it may cause unexpected deformation of other postures. In other words, due to the difference in the accuracy of the actuators, the actuators within the system may affect each other, resulting in unstable dynamic performance of the overall system.

[0004] In practical applications, unnecessary deformation postures are usually constrained by mechanical components such as hinges and springs, thereby limiting unnecessary movement. However, this constraint mechanism cannot completely eliminate unexpected deformation caused by inconsistent motion accuracy between actuators. In this case, the deformation trend often leads to mutual resistance between the actuators, forming the so-called "excess force" or "internal force conflict". The generation of these excess forces directly affects the control accuracy of the system and may cause the static output force of the actuator to decrease, thereby affecting the accuracy and reliability of the entire control system.

[0005] At present, the existing technology mainly reduces the influence of excess force in the system by improving the control accuracy of each actuator, improving the assembly process and improving the processing accuracy. However, although these methods can improve the system performance to a certain extent, they also have some limitations. For example, there is a limit to solving the problem simply by improving the accuracy of the actuator, because the improvement of the accuracy of each actuator is restricted by cost, technology and manufacturing process. In addition, it is often difficult to keep the dynamic characteristics of the actuators completely consistent, especially under complex load conditions, the response speed, inertia characteristics and nonlinear characteristics of each actuator may be different, thus affecting the overall coordination and stability of the system.

[0006] At the same time, processing and assembly errors are also issues that cannot be ignored. These errors are inevitably generated during the production and assembly process and will directly lead to inconsistencies between actuators. Even with high-precision manufacturing technology, it is difficult to completely eliminate these errors. Due to the existence of these errors, asynchronous movements may occur between the actuators, resulting in unbalanced forces or torques in the system, further exacerbating the generation of excess forces. Summary of the invention

[0007] The present invention aims at the problems of poor control system accuracy, high noise, low static output, etc. caused by redundant force disputes in existing statically indeterminate systems, and proposes a method for eliminating redundant force disputes in statically indeterminate systems. The method comprises:

[0008] Constructing a hyperstatic system, the hyperstatic system comprising: a conventional rigid body position loop and a redundant force control loop;

[0009] Obtain rigid body posture decomposition factors based on hyperstatic system;

[0010] Calculate the rigid body posture synthesis factor according to the rigid body posture decomposition factor;

[0011] Calculate the deformation posture decomposition factor according to the rigid body posture synthesis factor;

[0012] generating a position correction control signal according to a redundant force controller and a deformation posture decomposition factor;

[0013] Generate a control signal of the position loop according to the posture controller and the rigid body posture decomposition factor;

[0014] The position correction control signal and the position loop control signal are superimposed as the input signal to excite the system and eliminate the redundant force disputes.

[0015] Furthermore, a preferred embodiment is proposed, wherein the hyperstatic system is:

[0016] KM T f c +KT T f d =Kf

[0017] Among them, M is the pose synthesis factor, f c To achieve rigid pose s c Output of the actuator, f d is the deformation pose s d The output of the actuator, K is the redundant force synthesis factor, T represents the mapping relationship from the actuator displacement to the deformed posture, and f is a vector.

[0018] Furthermore, a preferred embodiment is proposed, in which the dimension of the posture synthesis factor is n×m, wherein n represents the number of actuators and m represents the number of rigid body postures achieved.

[0019] Furthermore, a preferred method is proposed, wherein the rigid body posture synthesis factor is calculated according to the rigid body posture decomposition factor, including:

[0020] M=(N T N) -1 N T

[0021] Among them, N T is the transpose of the pose decomposition factor.

[0022] Furthermore, a preferred method is proposed, wherein the deformation posture decomposition factor is calculated according to the rigid body posture synthesis factor, including:

[0023] MJ=0

[0024] Among them, J is the posture decomposition factor of the system to achieve the deformed posture.

[0025] Furthermore, a preferred embodiment is proposed, wherein the deformation posture decomposition factor generates a position correction control signal, including:

[0026] K=J T .

[0027] Furthermore, a preferred embodiment is proposed, wherein the method further comprises: when the position correction control signal and the position loop control signal are superimposed as the input signal excitation system, the redundant force control loop force input signal is set to 0.

[0028] Based on the same inventive concept, the present invention also proposes a computer device, including a memory and a processor, wherein the memory stores a computer program. When the processor runs the computer program stored in the memory, the processor executes a method for eliminating redundant force disputes in an over-statically indeterminate system according to any one of the above items.

[0029] Based on the same inventive concept, the present invention also proposes a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of a method for eliminating redundant force disputes in an over-statically indeterminate system as described in any one of the above are executed.

[0030] The present invention is beneficial in that:

[0031] The method proposed in the present invention accurately controls the posture of the rigid body by decomposing the posture factor and synthesis factor of the rigid body, ensuring that each force and constraint in the system can be correctly distributed under the action of the controller, thereby reducing the redundant force disputes in the system. By using the superposition of the position correction control signal and the position loop control signal, the oscillation and noise caused by the redundant force can be effectively eliminated, making the response of the system more stable, and avoiding the strong oscillation phenomenon caused by the redundant force in the traditional hyperstatic system. By accurately calculating the posture decomposition factor, generating a control signal according to the deformed posture decomposition factor, and optimizing the controller's regulation of the redundant force, the static output of the system can be improved, making the force output of the hyperstatic system more effective.

[0032] The method proposed in the present invention can effectively control the position and posture of the rigid body and reduce the error caused by the redundant force, thereby improving the accuracy of the control system by reasonably decomposing and synthesizing the posture factors. The control loop of the redundant force and the position correction control signal can effectively eliminate the system instability caused by the struggle of the redundant force, reduce oscillation and noise, and ensure that the system runs more smoothly. Through precise posture control and correction, the distribution of force is more reasonable, ensuring that the hyperstatic system can provide sufficient static output, thereby improving the execution ability and efficiency of the system. Due to the precise control of the posture factors, combined with the superposition of the correction control signal, the response of the system is smoother, and the influence of dynamic noise on the stability of the system is reduced.

[0033] The present invention is applied to the control of hyperstatic systems in ground test equipment in the fields of transportation, aerospace, civil engineering, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of a method for eliminating redundant force disputes in an over-statically-determined system as described in Implementation Method 1;

[0035] Figure 2 Schematic diagram of a hyperstatic system according to Embodiment 10;

[0036] Figure 3 A schematic diagram of deformation caused by excess force according to the tenth embodiment;

[0037] Figure 4 This is a double-channel structural layout diagram of a certain type of vehicle-mounted crane arm described in Embodiment 10;

[0038] Figure 5 This is a structural layout diagram of a certain type of automobile testing center according to Implementation Example 10;

[0039] Figure 6 This is a layout diagram of a certain type of hyperstatic structure described in Embodiment 10;

[0040] Figure 7 This is a diagram showing the effect of eliminating excess force as described in the tenth embodiment. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0042] Implementation method 1, see Figure 1 The present embodiment describes a method for eliminating redundant force conflicts in an over-static system, the method comprising:

[0043] Constructing a hyperstatic system, the hyperstatic system comprising: a conventional rigid body position loop and a redundant force control loop;

[0044] Obtain rigid body posture decomposition factors based on hyperstatic system;

[0045] Calculate the rigid body posture synthesis factor according to the rigid body posture decomposition factor;

[0046] Calculate the deformation posture decomposition factor according to the rigid body posture synthesis factor;

[0047] generating a position correction control signal according to a redundant force controller and a deformation posture decomposition factor;

[0048] Generate a control signal of the position loop according to the posture controller and the rigid body posture decomposition factor;

[0049] The position correction control signal and the position loop control signal are superimposed as the input signal to excite the system and eliminate the redundant force disputes.

[0050] The method proposed in this embodiment accurately controls the posture of the rigid body by decomposing the posture factor and synthesis factor of the rigid body, ensuring that each force and constraint in the system can be correctly distributed under the action of the controller, thereby reducing the redundant force disputes in the system. By using the superposition of the position correction control signal and the position loop control signal, the oscillation and noise caused by the redundant force can be effectively eliminated, making the response of the system more stable, and avoiding the strong oscillation phenomenon caused by the redundant force in the traditional hyperstatic system. By accurately calculating the posture decomposition factor, generating a control signal based on the deformed posture decomposition factor, and optimizing the controller's regulation of the redundant force, the static output of the system can be improved, making the force output of the hyperstatic system more effective.

[0051] The method proposed in this embodiment can effectively control the position and posture of the rigid body by reasonably decomposing and synthesizing the posture factors, reduce the errors caused by the redundant forces, and thus improve the accuracy of the control system. The redundant force control loop and the position correction control signal can effectively eliminate the system instability caused by the struggle of the redundant forces, reduce oscillations and noise, and ensure that the system runs more smoothly. Through precise posture control and correction, the distribution of force is more reasonable, ensuring that the hyperstatic system can provide sufficient static output, thereby improving the execution ability and efficiency of the system. Due to the precise control of the posture factors, combined with the superposition of the correction control signal, the response of the system is smoother, reducing the impact of dynamic noise on the stability of the system.

[0052] Implementation method 2: This implementation method further limits the method for eliminating redundant force disputes in an over-statically-determined system described in implementation method 1. The over-statically-determined system is:

[0053] KM T f c +KT T f d =Kf

[0054] Among them, M is the pose synthesis factor, f c To achieve rigid pose s c Output of the actuator, f d is the deformation pose s d The output of the actuator, K is the redundant force synthesis factor, T represents the mapping relationship from the actuator displacement to the deformed posture, and f is a vector.

[0055] Implementation method three: This implementation method is a further limitation of the method for eliminating redundant force disputes in an over-statically determinate system described in implementation method one. The dimension of the posture synthesis factor is n×m, where n represents the number of actuators and m represents the number of rigid body postures achieved.

[0056] Embodiment 4: This embodiment further limits the method for eliminating redundant force disputes in an over-statically-determined system described in Embodiment 2. The method for calculating the rigid body posture synthesis factor based on the rigid body posture decomposition factor includes:

[0057] M=(N T N) -1 N T

[0058] Among them, N T is the transpose of the pose decomposition factor.

[0059] Embodiment 5: This embodiment further limits the method for eliminating redundant force disputes in an over-statically-determined system described in Embodiment 2. The method for calculating the deformation posture decomposition factor based on the rigid body posture synthesis factor includes:

[0060] MJ=0

[0061] Among them, J is the posture decomposition factor of the system to achieve the deformed posture.

[0062] Embodiment 6: This embodiment further limits the method for eliminating redundant force disputes in an over-statically-determined system described in embodiment 5. The deformation posture decomposition factor generates a position correction control signal, including:

[0063] K=J T .

[0064] Implementation method seven. This implementation method is a further limitation of a method for eliminating redundant force disputes in an over-statically indeterminate system as described in any one of implementation methods one to six, and the method also includes: when the position correction control signal and the position loop control signal are superimposed as input signals to excite the system, the redundant force control loop force input signal is set to 0.

[0065] Embodiment 8. A computer device described in this embodiment includes a memory and a processor, wherein the memory stores a computer program. When the processor runs the computer program stored in the memory, the processor executes a method for eliminating redundant force disputes in an over-statically indeterminate system as described in any one of embodiments 1 to 7.

[0066] Embodiment 9. A computer-readable storage medium described in this embodiment stores a computer program, and when the computer program is executed by a processor, the steps of a method for eliminating redundant force disputes in an over-statically indeterminate system as described in any one of embodiments 1 to 7 are executed.

[0067] Implementation Method 10: See Figures 2 to 7 This embodiment provides a specific example of a method for eliminating redundant force disputes in an over-statically-determined system described in the first embodiment, and is also used to explain the second to seventh embodiments, specifically:

[0068] like Figure 2 As shown in the figure, suppose there are n actuators in the hyperstatic system, and the displacement and output of each actuator are represented by y i 、f i (i=1,…,n) represents the vector y and f. To achieve the rigid body pose s c =[s c,1 s c,2 Ks c,m ] T The number is m, then the deformation posture (such as Figure 3 (shown) d =[s d,1 s d,2Ks d,n-m ] T The number is nm, then we have

[0069]

[0070] Among them, N and J are the posture decomposition factors of the system to realize rigid posture and deformation posture, and the dimensions are n×m and n×(nm) respectively.

[0071] Corresponding to N is the pose synthesis factor M, the dimension is m×n, and there are s c =My,MN=I m , which can be obtained by taking the pseudo-inverse of N

[0072] M=(N T N) -1 N T (2)

[0073] Multiplying both sides of equation (1) by M, we have

[0074] MJ=0 (3)

[0075] J consists of M null space basis vectors, with dimension n×(nm), which can be obtained by finding the M null space rational basis.

[0076] Assume that the rigid pose s is achieved c The actuator output is expressed as f c =[f c,1 f c,2 K c,m ] T , the corresponding deformation pose s d The actuator output is expressed as f d =[f d,1 f d,2 K d,n-m ] T , then

[0077]

[0078] Let T represent the mapping relationship from actuator displacement to deformation posture, that is, s d =Ty, the dimension is (nm)×n, then equation (4) becomes

[0079] M T f c +T T f d =f (5)

[0080] Let K be the redundant force synthesis factor, which represents the mapping relationship between the actuator output and the deformation posture force, that is, f d =Kf, the dimension is (nm)×n, since fc =0 when T T f d =f, so KT T =I n-m From equation (4), we have

[0081] KM T f c +KT T f d =Kf (6)

[0082] Therefore, equation (6) becomes KM T = 0. Considering equation (3), we have

[0083] K=J T (7)

[0084] It can be seen that in the deformation posture, the force synthesis factor K and the posture decomposition factor J are the same as the rigid body posture, and are in a transposed relationship with each other.

[0085] The process of eliminating excess force is as follows:

[0086] 1) First, the rigid body posture decomposition factor N is given according to the specific structure of the system;

[0087] 2) Calculate the rigid body posture synthesis factor M = (N T N) -1 N T

[0088] 3) Calculate the deformation posture decomposition factor J, satisfying MJ = 0

[0089] 4) Calculate the excess force synthesis factor K = J T

[0090] Control block diagram Figure 1 The whole system control consists of two control loops: one is the conventional rigid body position loop, and the other is the redundant force control loop. In the position loop, the displacement values ​​y1, y2, ..., y collected by the displacement sensor are n , which is converted from the rigid body posture synthesis factor M to the posture signal s c,1 ,s c ,2,…,s c,m , and superimposed with the posture command to form a control deviation signal. Then, the control signal of the position loop is generated through the posture controller and the rigid body posture decomposition factor N. In the redundant force control loop, the output values ​​of the actuator f1, f2, ..., f are collected by the force sensor. n , converted from the excess force synthesis factor K to the excess force signal f d,1 ,f d,2 ,…,f d,n-m, and is superimposed with the force command signal to form a force deviation signal. Then, the position correction control signal is generated through the redundant force controller and the deformation posture decomposition factor J in turn. The position correction control signal is superimposed with the above-mentioned position loop control signal as the input signal to excite the system. In order to eliminate the redundant force disputes in the system, the redundant force control loop force input signal command is 0.

[0091] In order to verify the effect of this method, actual simulations were also carried out. Figure 4 As shown, actuators 1 and 2 simultaneously excite the boom of the truck crane. Before excitation, the boom is locked by the truck crane system so that the boom can only rotate in one position. Therefore, n = 2, m = 1, and the above redundant force control process is:

[0092]

[0093] In the figure, a=2, b=4.

[0094] Figure 5 In the above, actuators 1 to 8 simultaneously excite the vehicle wheel system. Before excitation, the control system can only move in the X-direction, Y-direction and yaw rotation of the Z axis through the constraint device. Therefore, n = 8, m = 3, and the above redundant force control process is:

[0095]

[0096] Figure 6 In the example, actuators 1 to 8 simultaneously stimulate the seismic simulation platform to simulate the six rigid body positions in space. Therefore, n = 8, m = 6, and the redundant force control process is as follows:

[0097]

[0098]

[0099] Figure 7 The effect diagram after applying the redundant force elimination method to the system shows that the redundant force is obviously eliminated by adopting this method.

[0100] Although the preferred embodiments of the present disclosure have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present disclosure.

[0101] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to include these modifications and variations.

[0102] Those skilled in the art will appreciate that the embodiments of the present disclosure may be provided as methods, systems or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0103] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a 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 an instruction device, which implements the functions specified in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure rather than to limit its protection scope. Although the present disclosure has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present disclosure, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the disclosed claims to be approved.

Claims

1. A method for eliminating redundant force disputes in an over-static system, characterized in that: The method comprises: Constructing a hyperstatic system, the hyperstatic system comprising: a conventional rigid body position loop and a redundant force control loop; Obtain rigid body posture decomposition factors based on hyperstatic system; Calculate the rigid body posture synthesis factor according to the rigid body posture decomposition factor; Calculate the deformation posture decomposition factor according to the rigid body posture synthesis factor; generating a position correction control signal according to a redundant force controller and a deformation posture decomposition factor; Generate a control signal of the position loop according to the posture controller and the rigid body posture decomposition factor; The position correction control signal and the position loop control signal are superimposed as the input signal to excite the system and eliminate the redundant force disputes.

2. A method for eliminating redundant force conflicts in an over-statically-determined system according to claim 1, characterized in that: The hyperstatic system is: KM T f c +KT T f d =Kf Among them, M is the pose synthesis factor, f c To achieve rigid pose s c Output of the actuator, f d is the deformation pose s d The output of the actuator, K is the redundant force synthesis factor, T represents the mapping relationship from the actuator displacement to the deformed posture, and f is a vector.

3. A method for eliminating redundant force conflicts in an over-statically-determined system according to claim 1, characterized in that: The dimension of the posture synthesis factor is n×m, where n represents the number of actuators and m represents the number of rigid body postures achieved.

4. A method for eliminating redundant force conflicts in an over-static system according to claim 2, characterized in that: The step of calculating the rigid body posture synthesis factor according to the rigid body posture decomposition factor includes: M=(N T N) -1 N T Among them, N T is the transpose of the pose decomposition factor.

5. A method for eliminating redundant force conflicts in an over-static system according to claim 2, characterized in that: The step of calculating the deformation posture decomposition factor according to the rigid body posture synthesis factor includes: MJ=0 Among them, J is the posture decomposition factor of the system to achieve the deformed posture.

6. A method for eliminating redundant force conflicts in an over-static system according to claim 5, characterized in that: The deformation posture decomposition factor generates a position correction control signal, including: K=J T 。 7. A method for eliminating redundant force disputes in an over-static system according to any one of claims 1 to 6, characterized in that: The method further comprises: when the position correction control signal and the position loop control signal are superimposed as the input signal to excite the system, setting the redundant force control loop force input signal to 0.

8. A computer device, characterized in that: It comprises a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes a method for eliminating redundant force disputes in an over-statically-determined system according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, executes the steps of a method for eliminating redundant force disputes in an over-statically indeterminate system as described in any one of claims 1-7.

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