Fpga-based Switching Principle With The Reconstruction Method And Its Applications In Fault-tolerant Control

Fault tolerance technology is an effective approach for enhancing reliability and safety of electro-mechanical products(EMPs). Switching principles and reconfiguration methodology of fault tolerance control are taken as the main clue. Based on field programmable gate array(FPGA), combining predictive control theory with embedded control technology, switching principles and reconfiguration methodology in fault tolerance control are studied deeply and systemly in this paper.Based on the idea of redundant fault-tolerant, a dual CPU fault-tolerant controller is designed in this paper. Fault detection function and fault recovery mechanism for above controller are studied, system performance and fault recovery time are analysed. The switching principle and reconfiguration method of above controller are analysed and studied, switching simulation of FPGA arbiter based on hardware description language(HDL) is given, and an effective control law reconfiguration method, which can realize the self-compensation in the case of system failure, is presented in this paper.A fault tolerance reconfigurable approach for sensor faults of hybrid machine tools(HMTs) is presented in this paper, function of fault tolerance and fault rectification for three driving legs is realized via mounting redundant sensor in the middle passive leg. Corresponding algorithms of fault tolerance reconfiguration for displacement sensors and velocity sensors are deduced utilizing spatial closed chain constrain relationship. Simulation researches for fault tolerance performance of above reconfigurable approach are conducted by emulation of sensor fault. Hardware implementation method for above algorithm is studied based on FPGA and coordinate rotation digital computer (CORDIC) algorithm.A multi-model switching control system is presented based on generalized predictive control technology. Prediction models of this control system can switch automatically under the control of switching logic according to the current system state. In order to reduce switching disturbance and drastic change of control variable, a reconfiguration approach for prediction matrix is presented, smooth swiching for prediction model can be achieved. The switching performance and control effect of a four-model control system are simulated using square-wave trajectories.Based on idea of three-model redundant fault-tolerant, a FPGA based embedded fault-tolerant control system is designed based on Nios II, this system consists of a variety of IP core modules which are connected by Avalon bus. A fault-tolerant embedded hardware platform is built using EP1C6Q240C8 FPGA and some other peripheral devices; the system hardware and software are designed based on Nios II IDE and SOPC Builder development platform; and the real-time operating systemμC/OS-II is transplanted to the Nios II processor.FPGA based switching principles and reconfiguration methodology for fault tolerance control system presented in this paper will provide some effective theories, methodologys and techniques for the design of fault tolerance control system of EMPs.