Design and development of a cost efficiency robot arm with a PLC-based robot controller

Abstract

To develop a cost-efficient robot arm for a typical pick and place application that can applied in industry, this paper deployed a programmable logic controller (PLC) to control the rotation motion of the robot joints. The main tasks of the PLC controller are to calculate the kinematics, create high-speed pulse outputs for stepper motors, and implement sequence operations for a certain application. Functions are written into subprogram segments. When needed, the main program only turns on the corresponding flag for executing the subprogram. Using the pre-written subprograms, a logical sequence to implement the Pick and Place application is easily implemented and described in this paper. The PLC program is developed to control a SCARA robot with three rotation joins. Stepper motors drive the robot joints. The Delta DVPSV2 PLC is utilized to design the robot controller. This PLC series has four high-speed pulse output pins, which is suitable for this project. Synchronous motion of stepper motors is easily performed using high-speed pulse output commands built into the PLC program. Experimental results of robot arm control have demonstrated the efficiency and accuracy of the developed program. The robot arm's forward and inverse kinematics problems are verified using the simulator on the software. The robot's joints move synchronously as required to perform pick-and-place applications.