Research On Structure And Control System Of 4-DOF Delta Parallel Manipulator

In more than half a century, with the requirement of industrial manufacturing, the parallel manipulator has been widely studied. Compared with serial manipulator, parallel manipulator has advantages of high precision, strong structure stiffness, stable dynamic performance. But Chinese research of the Delta manipulator is relatively backward, Delta manipulator as the mainstream parallel robot, its research is extremely urgent. But there was still some application problems in our country, which mainly focus on the following research aspects: kinematics, working space, clearance analysis, trajectory planning, control platform, etc.. This paper takes the Delta parallel manipulator as the research object, and completed the work by following aspects.(1)The design based on the existing four degree of freedom Delta robot, improved the structure of the robot. At the same time, kinematics forward and inverse solution formula were derived by combined with the algebraic and geometric methods. Innovatively, kinematics formula was decomposed into three spherical cluster equations. The example was given by using MATLAB software.(2)To study the workspace, this paper using the Jacobian matrix and the condition number of Jacobian matrix, optimized the size of the Delta mechanism, obtained the mathematical expression for the speed and acceleration of the end effector, analysed the singularity of the mechanism. The analysis of the workspace was made combined with MATLAB software.(3)In the trajectory planning part, this paper based on the "gate" path optimized the work path. The superellipse curve was introduced and the concrete expression of the motion path was given. The modified trapezoid acceleration curve and the polynomial acceleration curve were be proposed, and the comparison was made between them to select a reasonable acceleration curve, at last the method of subsection interpolation for motion trajectory was applied.(4)The Delta robot platform combined with domestic control platform, to achieve the requirements by the advantages of lower cost and easier to use of the domestic control system, made the selection and connection for the control system.To sum up, this paper made an innovation of the structure of Delta manipulator, investigated and optimized a set of method for the kinematics, workspace, trajectory planning, and use of domestic control parts for Delta manipulator control platform.