Multiple Faults Detection and Isolation via Decentralized Sliding Mode Observer for Reconfigurable Manipulator

Abstract

-This paper considers a decentralized multiple faults detection and isolation (FDI) scheme for reconfigurable manipulators. Inspired by their modularization property, a global sliding mode (GSM) based stable adaptive fuzzy decentralized controller is investigated for the system in fault free, while for the system suffering from multiple faults (actuator fault and sensor fault), the decentralized sliding mode observer (DSMO) is employed to detect their occurrence. Hereafter, the time and location of faults can be determined by a fault isolation scheme via a bank of DSMOs. Finally, the effectiveness of the proposed schemes in controlling, detecting and isolating faults is illustrated by the simulations of two 3-DOF reconfigurable manipulators with different configurations successfully.

Ultrasonic Adaptive Detection for Aerospace Components with Varying Thickness

“…When the specimen is grasped by the robot, the transform matrix describes the orientation of { } relative to { }, which can be calculated based on the Denavit-Hartenberg parameters [18][19][20]. Considering that the robot manipulator has 6 degrees of freedom, the forward kinematics solution is solved and the rotation matrix is given by the following equation:…”

Sliding mode-based online fault compensation control for modular reconfigurable robots through adaptive dynamic programming

“…In recent years, several researches on MRRs control approaches have been attracted a great deal of attention, such as centralized control [4,5], distributed control [6,7], and decentralized control [8,9]. These control approaches mainly tackled force/position control problems [10,11], fault tolerant control problems [12,13], and so on. Despite above methods have achieved good performance, the designed controller always contain some adjustable parameters, which increase the design difficulty and structural complexity.…”

“…Owing to the low sensitivity and robustness to system uncertainties and external disturbances, sliding mode control (SMC) reduces the necessity of accurate model, and is feasible to apply to design control systems no matter in normal or faulty conditions [41][42][43]. Hence, SMC methods always have been applied to systems with high nonlinearities, variable parameters and external disturbances, such as aircraft systems [44], direct current (DC) servomotors [45], multi-machine power systems [46] and MRRs [12].…”