Design And Research Of A Cable-Driven Linear Actuator

Precision driving and positioning technology is one of the main supporting technologies in many fields,such as: modern medical,biotechnology,ultra-precision processing,aerospace and other fields.Linear actuator is a functional component which can provide linear motion,and this technology has been widely used in the mentioned fields.Ball screw linear actuator,synchronous belt linear actuator and other traditional forms are more difficult to meet the application requirements of higher-precision transmission occasions due to their own structural forms and transmission methods.Therefore,it is urgent to adopt some new transmission methods to solve these problems.Cable-driven is becoming a hot spot in the field of precision transmission research due to its high precision,flexible layout,lightweight and other advantages.Considering the advantages and characteristics of cable-driven,this paper proposes a design scheme of linear actuator based on flexible cable-driven and conducts in-depth theoretical research on it.The main research contents are as follows:First of all,the transmission principle of the cable-driven linear actuator is explained,and the classical Newtonian mechanics is used for structural analysis.The mapping relationship between the load and the driving torque of the linear actuator in the no-load state and in a variety of different stress states is derived.Secondly,the transmission characteristics of the cable-driven linear actuator is analyzed by using the classical creep theory and Euler equation.The formula for calculating the tension of the cables in the sliding zone where the flexible cable is in contact with the drive shaft is established.The analytic expressions for the transmission error and transmission stiffness of the cable-driven linear drive are deduced.And the influence on the transmission error of the linear actuator which caused by the factors such as preload and friction coefficient.are analyzed by MATLAB.Thirdly,the Adams/Cable module is used to establish a linear actuator virtual prototype model and perform simulation analysis,by using the virtual prototype technology,which proves the correctness of the kinematics theoretical analysis results.Finally,an experimental prototype of the linear actuator is built.The transmission error of the linear actuator system is measured by the laser tracker in both the planned speed mode and the planned corner mode,and the transmission performance of the cable-driven linear actuator is objectively evaluated.