scholarly journals Fault-Tolerant Control Strategy for Steering Failures in Wheeled Planetary Rovers

2012 ◽  
Vol 2012 ◽  
pp. 1-15
Author(s):  
Alexandre Carvalho Leite ◽  
Bernd Schäfer ◽  
Marcelo Lopes de OLiveira e Souza
Keyword(s):  
Design Process ◽  
Impact Analysis ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Lessons Learned ◽  
The Real ◽  
Driving Mode ◽  
Planetary Rovers ◽  
Step Procedure ◽  
Nominal Mode

Fault-tolerant control design of wheeled planetary rovers is described. This paper covers all steps of the design process, from modeling/simulation to experimentation. A simplified contact model is used with a multibody simulation model and tuned to fit the experimental data. The nominal mode controller is designed to be stable and has its parameters optimized to improve tracking performance and cope with physical boundaries and actuator saturations. This controller was implemented in the real rover and validated experimentally. An impact analysis defines the repertory of faults to be handled. Failures in steering joints are chosen as fault modes; they combined six fault modes and a total of 63 possible configurations of these faults. The fault-tolerant controller is designed as a two-step procedure to provide alternative steering and reuse the nominal controller in a way that resembles a crab-like driving mode. Three fault modes are injected (one, two, and three failed steering joints) in the real rover to evaluate the response of the nonreconfigured and reconfigured control systems in face of these faults. The experimental results justify our proposed fault-tolerant controller very satisfactorily. Additional concluding comments and an outlook summarize the lessons learned during the whole design process and foresee the next steps of the research.

Robust H∞ fault tolerant control for quadrotor attitude regulation

2018 ◽  
Vol 232 (10) ◽  
pp. 1302-1313 ◽  
Author(s):  
Cong Li ◽  
Hui Jing ◽  
Jiading Bao ◽  
Shanlin Sun ◽  
Rongrong Wang
Keyword(s):  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Control Input ◽  
External Disturbances ◽  
The Real ◽  
Upper Level ◽  
Thrust Forces

This article investigates the robust H∞ fault tolerant control of quadrotor attitude regulation. The hover stability is heavily dependent on the thrust forces generated by the four rotors of the quadrotor. If faults occur in the rotors, the quadrotor becomes unstable, and possibly out of control. To this end, this article proposes a robust H∞ fault tolerant control schema, consisting of two level controllers, for regulation of the quadrotor attitude. The functions of the upper level controller and lower level controller are to generate the desired control input, and obtain the real input of the four rotors, respectively. In addition, the external disturbances are considered and attenuated by the controller. The simulation details are presented, and the effectiveness of the proposed control schema is verified.

RECONFIGURABLE CONTROL SYSTEM DESIGN FOR FAULT DIAGNOSIS AND ACCOMMODATION

2002 ◽  
Vol 12 (06) ◽  
pp. 497-520 ◽  
Author(s):  
LIANG-WEI HO ◽  
GARY G. YEN
Keyword(s):  
Fault Diagnosis ◽  
Control Problem ◽  
Real Time ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Effective Control ◽  
Dynamical Structure ◽  
The Real ◽  
Fault Accommodation ◽  
On Line

The growing demand in system reliability and survivability under failures has urged ever-increasing research effort on the development of fault diagnosis and accommodation. In this paper, the on-line fault tolerant control problem for dynamic systems under unanticipated failures is investigated from a realistic point of view without any specific assumption on the type of system dynamical structure or failure scenarios. The sufficient conditions for system on-line stability under catastrophic failures have been derived using the discrete-time Lyapunov stability theory. Based upon the existing control theory and the modern computational intelligence techniques, an on-line fault accommodation control strategy is proposed to deal with the desired trajectory-tracking problems for systems suffering from various unknown and unanticipated catastrophic component failures. Theoretical analysis indicates that the control problem of interest can be solved on-line without a complete realization of the unknown failure dynamics provided an on-line estimator satisfies certain conditions. Through the on-line estimator, effective control signals to accommodate the dynamic failures can be computed using only the partially available information of the faults. Several on-line simulation studies have been presented to demonstrate the effectiveness of the proposed strategy. To investigate the feasibility of using the developed technique for unanticipated fault accommodation in hardware under the real-time environment, an on-line fault tolerant control test bed has been constructed to validate the proposed technology. Both on-line simulations and the real-time experiment show encouraging results and promising futures of on-line real-time fault tolerant control based solely upon insufficient information of the system dynamics and the failure dynamics.

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