CN-115906581-B - Parameter optimization method and system for constant force mechanism

CN115906581BCN 115906581 BCN115906581 BCN 115906581BCN-115906581-B

Abstract

The invention discloses a parameter optimization method and a parameter optimization system for a constant force mechanism, which are applied to the technical field of the constant force mechanism, and the method comprises the following steps: the method comprises the steps of constructing a feasible initial flexible constant force mechanism, acquiring a plurality of initial structural parameters of the constant force mechanism, analyzing to acquire force-displacement characteristic curves of the constant force mechanism, analyzing the plurality of initial structural parameters to acquire a plurality of sensitive initial structural parameters, constructing constraint conditions and an optimization objective function, constructing a cost function describing the optimization objective function, optimizing the plurality of sensitive initial structural parameters based on the constraint conditions to acquire a plurality of optimization structural parameters, adjusting the constant force mechanism by adopting the plurality of optimization structural parameters to acquire the optimization constant force mechanism, and verifying the optimization constant force mechanism. The invention solves the technical problems of low efficiency of the parameter optimization method of the constant force mechanism caused by the lack of the method for automatically optimizing the parameters according to the constant force mechanism in the prior art.

Inventors

WANG GUANGWEI
Tong Zongdi

Assignees

贵州大学

Dates

Publication Date: 20260508
Application Date: 20221213

Claims (6)

1. A method for optimizing parameters of a constant force mechanism, the method comprising: Constructing a feasible initial flexible constant force mechanism, and acquiring a plurality of initial structural parameters of the initial flexible constant force mechanism; analyzing and obtaining a force-displacement characteristic curve of the initial flexible constant force mechanism; Carrying out parameterization analysis on the plurality of initial structural parameters to obtain a plurality of sensitive initial structural parameters with the greatest influence on the constant force characteristics of the initial flexible constant force mechanism; constructing constraint conditions and optimizing objective functions according to the sensitive initial structure parameters, Constructing a cost function describing the optimization objective function; Based on the constraint condition, the optimization objective function and the cost function, adopting a multi-objective genetic algorithm to optimize the sensitive initial structural parameters in an ANSYS Workbench to obtain optimized structural parameters; Adopting the plurality of optimized structural parameters to adjust the initial flexible constant force mechanism to obtain an optimized flexible constant force mechanism, and verifying the optimized flexible constant force mechanism; Analyzing and obtaining a force-displacement characteristic curve of the initial flexible constant force mechanism, wherein the force-displacement characteristic curve comprises the following steps: constructing an initial entity model by adopting Solidworks based on the initial structural parameters; Obtaining a force-displacement characteristic curve of the initial flexible constant force mechanism by adopting statics analysis; The sensitive initial structural parameters are respectively the out-of-plane thickness of the beam, the in-plane width of the beam, the inclination angle of the beam and the length of the beam, and the optimization objective function is as follows: Wherein, the In order to output the target constant force value, In order to output a constant force stroke, Representing the out-of-plane thickness of the beam, Representing the in-plane width of the beam, Indicating the angle of inclination of the beam, Representing the length of the beam, wherein the structural parameters of the initial negative stiffness mechanism and the initial positive stiffness mechanism are represented by different subscripts; The constraint conditions are as follows: Wherein, the Respectively the upper limit, the lower limit and the interval of the sensitive initial structure parameters; the cost function is as follows: Wherein, the As a function of the cost, 、、、 And Is a weight coefficient, and the sum of the weight coefficients is 1, Is a target constant force value , ) Representing the point of the selected sample, In order to be able to exert a force, For displacement, (P max -P 1 ) represents a constant force stroke, For slope, TDA is the overall deformation average, ESM is the maximum equivalent stress, and the optimization aims at obtaining Is a minimum of (2).
2. The method of claim 1, wherein said constructing a viable initial flexible constant force mechanism comprises: Adopting a rigidity combination mechanism design method to design and construct an initial negative rigidity mechanism and an initial positive rigidity mechanism; combining the initial negative stiffness mechanism and the initial positive stiffness mechanism to obtain the initial flexible constant force mechanism; Constructing an initial theoretical data model of the initial flexible constant force mechanism; importing the initial theoretical data model into Matlab for theoretical model verification, and judging whether the initial flexible constant force mechanism is feasible or not; And when the initial flexible constant force mechanism is feasible, adopting a manual trial and error method to carry out parameter adjustment on a plurality of design structural parameters of the initial flexible constant force mechanism until a preset condition is reached, and obtaining the initial flexible constant force mechanism and the plurality of initial structural parameters.
3. The method of claim 1, wherein adjusting the initial flexible constant force mechanism to obtain an optimized flexible constant force mechanism using the plurality of optimized structural parameters, and validating the optimized flexible constant force mechanism comprises: based on the optimized structure parameters, an optimized entity model is built in the Solidworks; obtaining a force-displacement characteristic curve of the optimized flexible constant force mechanism by adopting statics analysis; comparing the data of the force-displacement characteristic curve of the initial flexible constant force mechanism with the force-displacement characteristic curve of the optimized flexible constant force mechanism, and judging whether the force-displacement characteristic curve of the optimized flexible constant force mechanism reaches the error range of a preset target constant force value or not and whether the constant force stroke is enlarged or not; and carrying out experiments according to the initial flexible constant force mechanism and the printing entity of the flexible constant force mechanism, and verifying whether the optimized flexible constant force mechanism is feasible or not.
4. A parameter optimization system for a constant force mechanism, characterized in that the system is adapted to perform the method of any one of claims 1-3, the system comprising: the initial structure parameter acquisition module is used for constructing a feasible initial flexible constant force mechanism and acquiring a plurality of initial structure parameters of the initial flexible constant force mechanism; The characteristic curve construction module is used for analyzing and obtaining a force-displacement characteristic curve of the initial flexible constant force mechanism; The sensitive initial structure parameter acquisition module is used for carrying out parameterization analysis on the plurality of initial structure parameters to acquire a plurality of sensitive initial structure parameters with the greatest influence on the constant force characteristics of the initial flexible constant force mechanism; A constraint condition construction module for constructing constraint conditions and optimizing objective functions according to the sensitive initial structure parameters, The optimization objective function acquisition module is used for constructing a cost function describing the optimization objective function; The optimized structure parameter acquisition module is used for optimizing the sensitive initial structure parameters in an ANSYS Workbench by adopting a multi-objective genetic algorithm based on the constraint condition, the optimized objective function and the cost function to obtain optimized structure parameters; and the constant force mechanism verification module is used for adopting the plurality of optimized structural parameters to adjust the initial flexible constant force mechanism to obtain an optimized flexible constant force mechanism and verifying the optimized flexible constant force mechanism.
5. An electronic device, the electronic device comprising: A memory for storing executable instructions; A processor for implementing a method of optimizing parameters of a constant force mechanism according to any one of claims 1 to 3 when executing executable instructions stored in said memory.
6. A computer readable medium on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements a method for optimizing parameters of a constant force mechanism according to any of claims 1-3.

Description

Parameter optimization method and system for constant force mechanism Technical Field The invention relates to the technical field of constant force mechanisms, in particular to a parameter optimization method and system of a constant force mechanism. Background Precision manipulation has been rapidly developed in a variety of new applications over the last decades, including micromanipulation, biomedical research, precision optics, and precision assembly. In addition to ensuring precise positional control of micro-nano operations, due to irregular and fragile micro-scale object shapes, strict adjustment of the operating force within a proper range is required. There are two methods for achieving operational accuracy, force feedback control and mechanism design. The force feedback control adjusts the feedback force precisely through the controller, while the mechanism design adjusts the output force by adjusting the structural characteristics. Compared with the characteristics of complex force feedback control system and high cost, the mechanism design method has the advantages of economy, simplicity and the like, and is favored by researchers. In contrast to conventional elastic structures, constant force mechanisms do not obey hooke's law and their stiffness is quasi-zero during coupled buckling deformation, which enables flexible constant force mechanisms to provide nearly constant force output over a specific displacement range without feedback. Because the flexible constant force mechanism replaces a complex control system with its mechanical characteristics, a great deal of attention is gained because it significantly reduces the difficulty and complexity of conventional force feedback control systems. In many design research experiments related to flexible constant force mechanisms, because the mechanism design is based on mechanical theory, the problems of insufficient constant force stroke, inconsistent experiments and theory and the like often occur. Therefore, the constant force mechanism needs to be optimized, in the optimization research, researchers can manually adjust according to the parameter sensitivity result of the structural parameter, but the selected objective function is too single, the optimization objective is fuzzy, and only one conceptual optimization objective is provided, the optimization efficiency is low, the optimization cannot be performed according to a specific target value, and the structural parameter is difficult to automatically design according to the target constant force value. Therefore, the technical problem that the parameter optimization method of the constant force mechanism is complex and low in optimization efficiency is caused by the lack of the method capable of automatically optimizing the parameters according to the constant force mechanism in the prior art. Disclosure of Invention The application provides a parameter optimization method and a parameter optimization system for a constant force mechanism, which solve the technical problem that in the prior art, the parameter optimization method for the constant force mechanism is complex and has low optimization efficiency due to the lack of a method capable of automatically designing the parameter optimization according to the constant force mechanism. The application provides a parameter optimization method of a constant force mechanism, which comprises the steps of constructing a feasible initial flexible constant force mechanism, obtaining a plurality of initial structural parameters of the initial flexible constant force mechanism, analyzing and obtaining force-displacement characteristic curves of the initial flexible constant force mechanism, carrying out parameterization analysis on the plurality of initial structural parameters to obtain a plurality of sensitive initial structural parameters with the greatest influence on the constant force characteristics of the initial flexible constant force mechanism, constructing constraint conditions and optimization objective functions according to the plurality of sensitive initial structural parameters, constructing cost functions describing the optimization objective functions, optimizing the plurality of sensitive initial structural parameters in an ANSWorkbook based on the constraint conditions, the optimization objective functions and the cost functions by adopting a multi-objective genetic algorithm, obtaining a plurality of optimized structural parameters, adjusting the initial flexible constant force mechanism by adopting the plurality of optimized structural parameters, obtaining the optimized flexible constant force mechanism, and verifying the optimized flexible constant force mechanism. The application further provides a parameter optimization system of the constant force mechanism, which comprises an initial structure parameter acquisition module, a characteristic curve construction module, a sensitive initial structure parameter acquisition