Robust decoupling control of a parallel kinematic machine using the time-delay estimation technique

• Published in: Science China. Technological sciences Vol. 66; no. 7; pp. 1916 - 1927
• Main Authors: Zhang, HaiFeng, Ye, Wei, Li, QinChuan
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.07.2023; Springer Nature B.V
• Subjects: Controllers; Decoupling; Delay; Disturbances; Dynamic models; Engineering; Estimation; Kinematics; Robust control; Sliding mode control; System dynamics; Tracking; Uncertainty; Upper bounds; parallel kinematic machine; robust control; time delay estimation; sliding mode control
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-022-2371-3

This paper proposes a robust decoupling control scheme using a time-delay estimation technique for a parallel kinematic machine to enhance its trajectory tracking performance. The dynamic model of a parallel kinematic machine (PKM) is a multivariable nonlinear strongly coupled system that is always affected by uncertainties and external disturbances. The proposed controller employs the time-delay estimation (TDE) technique to estimate the dynamic model of a PKM with uncertainties and disturbances, thus obtaining a simple model structure. The TDE technique involves estimating the unknown system dynamics by intentionally using a time-delayed signal, which will inevitably lead to estimation errors. Hence, the proposed controller effectively reduces the unfavourable TDE error by combining fast and robust integral terminal sliding mode control with TDE (TDE-ITSMC). In turn, the TDE technique can reduce the upper bound on the switching gain in the sliding mode control (SMC) scheme, which reduces damage to the robot. Finally, comparative experimental studies with other controllers confirm that TDE-ITSMC offers excellent trajectory tracking accuracy and is a practical robust control scheme for PKMs.