Research On Model Of Fault Detection And Switching System That Can Realize Of Arbitrary Reliability

The redundancy technology is one of the main ways to improve the system reliability. There are one switch and several branches in a traditional fault detecting and switching system, thus system reliability is limited by the reliability of the switch. Although parallel system can reach arbitrary reliability, it wastes energy and life of its components, it may cause needless signal confusion.This thesis proposes innovative fault detecting and switching systems. The systems have distinctive characteristics: there are multiple parallel branches in a system, every branch has its fault detecting and switching device. All of the fault detecting and switching devices in the branches communicate with each other. When one of a branch fails, the fault detection devices in other branches can detect the failure one at once, then all backup branch immediately put into work. After system goes into stable state, the system automatically judges how many branches work normally, then leave one of the normal branch to work, let the rest branches quit and remain as a backup branches.The research of the thesis includes following aspects:Analyzing advantages and disadvantages of current available redundant systems, establishing a new kind of redundant system model which can avoid disadvantages of current available redundant systems. New redundant system can obtain desired reliability of system by increasing the number of branches and fault detecting and switching devices, up to arbitrary reliability. Comparing with other kind of redundant systems, such as parallel system, series- parallel systems, parallel-series systems and k/ n systems, new kind of redundant system can save much energy and lifetime of its components. Since the system outputs only one signal, it is impossible to produce mixture and crosstalk of output signals. It has higher reliability than existing fault detecting and switching redundant systems.Deducing the reliability calculation formula for the new type of fault detecting and switching system. proving theoretically the correctness and advancement of the system model, which provides a theoretical basis for the design and application of the redundant system. Designing redundant close loop control system by means of the system model.Designing the prototype of the new type of fault detecting and switching system. The prototype is electric circuit with 2 redundancies, which has three branches, three fault detecting and switching devices. The three fault detecting devices communicate with each other by CAN bus.Using the prototype to do experiments about system reliability. Proving the correctness and advancement of the redundant model by practical test.