Development of A Linear Delta Robot with Three Horizontal-Axial Pneumatic Actuators for 3-DOF Trajectory Tracking

• Published in: Applied sciences Vol. 10; no. 10; p. 3526
• Main Authors: Li, I-Hsum, Chiang, Hsin-Han, Lee, Lian-Wang
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2020
• Subjects: 3-DOF trajectory tracking; Accuracy; Air leakage; Analysis; Artificial neural networks; Compressed air; Control; Control algorithms; Controllers; Degrees of freedom (Mechanics); Design; Design and construction; fuzzy control; fuzzy-PID; Industrial robots; Kinematics; linear delta robot; Manufacturing; Mechanical properties; neural network (NN); Parameter identification; Pneumatic actuators; Robots; rod-less pneumatic actuators; Taiwan
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app10103526

This paper focuses on developing a pneumatic-driven and horizontal-structure linear delta robot (PH-LDR) and increasing its trajectory tracking performance on the three-degrees-of-freedom (3-DOF) space. With the investigation of inverse and forward kinematics, the parallel mechanism of PH-LDR is designed by using three high-power and low-cost rod-less pneumatic actuators (PAs) to track 3-DOF motion, and this has a horizontal structure to enlarge the workspace. Since the PH-LDR features nonlinear coupling among its three axes and is disturbed by the three high-nonlinear rod-less PAs, the tracking control performance is significantly decreased, subject to uncertain nonlinearity and parametric uncertainty. Therefore, a fuzzy-PID controller is used to achieve highly accurate 3-DOF trajectory tracking, and furthermore, this study exploits neural networks (NNs) to pre-compensate the impacts arising from the compressibility of air and temperature change. The control system for the PH-LDR also features an embedded controller that allows real-time control. Experimental demonstration verifies the developed PH-LDR with the proposed controller, and the dynamic tracking accuracy in 3-DOF trajectory can be achieved.