Research On Dielectric EAP-based Multilinkcable-driven Manipulators

As a new kind of smart materials, Dielectric EAP(Electro-active Polymer) has the advantage of lightweight, large strain, high energy density, fast response speed, etc., that is similar to natural muscle on the comprehensive performance. Dielectric EAP-based cable-driven manipulators that can mimic biological musculoskeletal system and provides a new drive form for parallel robot, which has important research value in the field of biomimetic robot.This paper designs a multilink cable-driven parallel manipulators which is composed of three series of rigid link and twelve cables. The jacobian matrix and inverse kinematics were derived based on the geometry features. Using orthogonal characteristics and constraints equation to establish a set of nonlinear equations, the forward kinematics can be derived.A rolled EAP actuator has been designed built on the deformation theory of Dielectric EAP, as well as the work process of cable-driven parallel manipulators. Higher output performance and good operating stability has been achieved by optimizing the structure of the actuator. The geometry and balance equations of actuator have been established, coupled with the constitutive equations and boundary conditions to get theoretical output displacement and force. Comparing theoretical analysis with experimental results and related factors was analyzed and discussed.A dielectric EAP-based cable-driven parallel joint has been designed. Building a test platform according to the characteristics of parallel joint; and design a motion control and data acquisition program with PID control algorithm to realize the real-time control and monitoring of the joint.Testing response characteristics of the joint response to the step and sinusoidal driving voltage signal. And utilizing maximum tangent method and ZN empirical method tuning PID controllers parameter in accordance with the open loop system response fitting curve. Point to point motion has been achieved. With the electromechanical coupling characteristics of the rolled actuator, combined with parallel joint kinematics and torque balance equations, calculate the excitation voltage according to a defined position and orientation parallel joints. Testing the output force of parallel joint and compare the theoretical value with the actual value of output force.Testing and analysis of multilink cable-driven parallel manipulators can be carried out on the basis of this study, and apply them to the study of biomimetic robots.