Constraint-Following Servo Control for the Trajectory Tracking of Manipulator with Flexible Joints and Mismatched Uncertainty

Trajectory tracking is a common application method for manipulators. However, the tracking performance is hard to improve if the manipulators contain flexible joints and mismatched uncertainty, especially when the trajectory is nonholonomic. On the basis of the Udwadia–Kalaba Fundamental Equation (U...

Full description

Saved in:
Bibliographic Details
Published inMachines (Basel) Vol. 9; no. 9; p. 202
Main Authors Dong, Fangfang, Yu, Bin, Zhao, Xiaomin, Chen, Shan, Liu, Haijun
Format Journal Article
LanguageEnglish
Published Basel MDPI AG 01.09.2021
Subjects
adaptive robust control
constraint-following
Control stability
Controllers
Design
Flexibility
flexible joint manipulator
Fuzzy logic
Lagrange multiplier
Manipulators
Neural networks
Robust control
Servocontrol
Theory of constraints
Tracking control
Trajectory control
Udwadia–Kalaba
uncertain system
Uncertainty
Online AccessGet full text

Cover

More Information
Summary:Trajectory tracking is a common application method for manipulators. However, the tracking performance is hard to improve if the manipulators contain flexible joints and mismatched uncertainty, especially when the trajectory is nonholonomic. On the basis of the Udwadia–Kalaba Fundamental Equation (UKFE), the prescribed position or velocity trajectories are creatively transformed into second-order standard differential form. The constraint force generated by the trajectories is obtained in closed form with the help of UKFE. Then, a high-order fractional type robust control with an embedded fictitious signal is proposed to achieve practical stability of the system, even if the mismatched uncertainty exists. Only the bound of uncertainty is indispensable, rather than the exact information. A leakage type of adaptive law is proposed to estimate such bound. By introducing a dead-zone, the control will be simplified when the specific parameter enters a certain area. Validity of the proposed controller is verified by numerical simulation with two-link flexible joint manipulator.
ISSN:2075-1702
2075-1702
DOI:10.3390/machines9090202