Experimental Study on the Pick-and-Place Operation of a 3-DOF Delta Parallel Robot

This paper presents kinematic analysis, verification, and workspace determination for the trajectory planning purpose of a 3-DOF Delta parallel robot. The under study Delta robot is the result of an academic collaboration between the Human and Robot Interaction Laboratory and the Tavan Resan Company. The dimension of the robot is obtained by using an algorithm for obtaining the optimal dimension of a Delta robot for a prescribed workspace defined from the outset. Analytical solutions for the forward and inverse kinematic problems of the under study robot are provided and verified in Simscape simulation. The workspace is determined using a discretization algorithm, in which joint limits and mechanical interference are taken into account to the end of obtaining a practical workspace. The robot's singular loci are determined, and visual inspection reveals that the robot entails a singularity-free workspace by considering joint limits, which can be regarded as a definite asset in practice. Finally, a 4-5-6-7 trajectory planning technique is implemented in order to make the manipulator's end-effector movement as smooth as possible for pick-and-place operations. Furthermore, experimental tests were executed to observe the robot's behavior and validate the kinematic equations experimentally.