Design And Research Of High Precision Parallel Micromechanism Based On Temperature Compensation

Parallel micro mechanisms mostly transmit force and motion through the deformation of materials,which have the advantages of frictionless and clearance free,and are often used in precision engineering.One of the key metrics for assessing the effectiveness of parallel micro mechanisms is precision,which is primarily affected by driving,processing,environmental temperature.It is vital to consider how variations in environmental temperature affect the mechanism.Environmental temperature changes can cause unexpected thermal deformation in parallel micro mechanisms,seriously affecting their normal operation,conducting temperature compensation design for mechanisms is a crucial aspect of precision research in parallel micro mechanisms.This article proposes a new equivalent flexibility matrix modeling method based on the flexibility matrix,which considers the temperature changes of the rod.Based on the equivalent flexibility matrix of the mechanism,from the perspective of innovative design of the mechanism,a new temperature compensation strategy is proposed,and a reasonable temperature compensation module is designed.kinematics,error analysis and experimental research are carried out on the compensated mechanism,which provides a new method to eliminate the influence of temperature on the accuracy of parallel micromanipulation.Firstly,using the theory of thermoelastic mechanics,the method of applying a load instead of heating is used to achieve a single mechanical modeling of a mixed model of thermodynamics and mechanics.Based on the theory of flexibility matrix,a new method for modeling equivalent flexibility matrix considering the temperature variation of the rod is proposed.Taking a 2-PP parallel micro mechanism as an example,the equivalent flexibility matrix of the mechanism is established.Secondly,based on the equivalent flexibility matrix of the mechanism,a design method for the temperature compensation module of the parallel micro mechanism is proposed.From the perspective of mechanism innovation,a new type of 2-PP parallel micro mechanism with temperature compensation capability is designed using the 2-PP parallel micro mechanism as an example.Through finite element simulation,the thermal deformation of the mechanism at different temperatures and the output displacement of the mechanism under different loading conditions were analyzed.The results showed that the new 2-PP parallel micro mechanism has good temperature compensation ability and static characteristics.Then,the kinematics model of the proposed new 2-PP parallel micromanipulator is established,the error source of the mechanism is analyzed,and the error model of the mechanism is established.Using finite element simulation to analyze the error of the mechanism,obtain the error weights of various parameters of the mechanism,and provide reference for mechanism processing.Finally,the physical prototype of the micro mechanism was processed,and an experimental platform was built to conduct experimental research on the bearing capacity and displacement of the micro mechanism at different temperatures.At the same time,the positioning accuracy and repeated positioning accuracy of the mechanism were tested under different loading conditions.The experimental results demonstrate that the micro mechanism has good temperature compensation ability and linear input-output characteristics.