Fault Diagnosis And Fault Tolerant Control For Networked Manipulators System

The continuous development of industrial systems Advances in science and technology have promoted towards large-scale,multi-functional and highly integrated directions.At the same time,manipulators are widely used in industrial environments due to their excellent adaptability and good operability.While pursuing economic benefits,the safety and stability of the manipulator systems should also be valued.How to detect the fault quickly and eliminate the influence of the fault after the fault of the manipulator has been an important content of fault diagnosis and fault-tolerant control of the manipulator.With the application of communication networks in control systems,fault diagnosis and fault tolerance control of networked manipulator systems are also worthy of paying attention.Based on the model of a two-link manipulator,the fault diagnosis and fault-tolerant control design is mainly studied in this thesis when the sensor fault of the manipulator occurs,as well as the faults of the actuators of the networked manipulator system and the schemes of fault diagnosis and fault-tolerant control of the networked manipulator cooperation system,and the effectiveness of the research can be proved by MATLAB simulation.(1)When a sensor fault occurs in a manipulator,the fault system model can be established,and by introducing a state variable,fault diagnosis and fault-tolerant control of the sensor fault can be transformed into fault diagnosis and fault-tolerant control of the actuator fault.An adaptive observer is designed to detect faults.And an active fault-tolerant controller combining the proportional differential controllers and sliding mode controllers is designed to further eliminate the impact of faults on the system and ensure the stability of the manipulator system;(2)Fault diagnosis and fault-tolerant control of actuator fault in a networked manipulator system are studied by using the above-mentioned adaptive observer and fault-tolerant controller.In the research,the delay effect brought by the network to the system is considered.Assuming that the system has a constant time delay,the states obtained in the system are all states after the delay.When the actuator of the manipulator system fails,the fault of the actuator is diagnosed by using the adaptive observer.After the fault information is obtained,a fault-tolerant controller is designed to further eliminate the fault and the time-delay to ensure the stability of the manipulator system;(3)Further research on the fault diagnosis and fault-tolerant control in the networked manipulator cooperation is considered.Assume that in a networked manipulator collaboration system,two manipulators work together to complete a collaborative task,and the faulty manipulator has a multiplicative actuator fault.The adaptive observer is used to estimate the fault;To ensure the successful completion of the cooperative task,two fault-tolerant control schemes are proposed: One is to design a fault-tolerant controller directly on the faulty manipulator.The other is to reconfigure the controller of the normal manipulator to achieve the overall fault-tolerant effect.Both of these fault-tolerant control schemes can ensure the stable operation of the cooperative system after the fault occurs.