Research On Semi-analytic Modleing And Robust Design Optimization For Electromgnetic Relay

TO-5 electromagnetic relay is a miniature kind with rotational electromagnetic system. It is widely used for electronic system in astronautic apparatus like missile and satellite on account of its high-quality performance of seal and anti-vibration. Therefore the reliability of TO-5 exactly determines whether the electronic circuit with TO-5 can complete the assigned task. In this paper a whole calculation model was established and then two problems are focused. Based on this fast and accurate model, particle performance optimization is applied to handle the deficiency of some performance. Then robust design and tolerance assignment was researched for TO-5 to decrease the output parameter range among a batch, which is so great that the reliability is impaired seriously.First a semi-analytical model was established based on Magnetic Equivalent Circuit method and FE method. To achieve fast calculation Magnetic Equivalent Circuit method is applied for electromagnetic system modeling. And to ensure accuracy, compensation matrix Cm×n is introduced to compensate the errors caused by flux leakage and saturation according to results obtained from the Finite Element method. As a counterpart Deformation Energy method is used for analytical modeling for mechanical system which includes mainly recoverable reed producing counter-force. Thus dynamic modeling and the subsequent dynamic parameters can be available by solving Ordinary Differential Equations by 4th order Runge-Kutta method and the comparison with results from FE method indicates the feasibility and efficiency of the new approach.Then the breaking speed and closure speed of the contact, which are closely related to electrical arc making and contact loss caused by bounce respectively, are combined as an objective function to optimize with one of the stochastic approaches-Particle Swarm(PS) algorithm. Thus an optimum combination of input parameters can be obtained.Additionally based on the fast calculation model, robust design and tolerance assignment are implemented to improve the conformity of TO-5 relays. Robust design needs the linear or non-linear property of the input parameter. Then the design value of the non-linear is altered to improve the stability of the system itself, making the system insensitive to the fluctuation of machining parameter. Another solution is to select the important parameters and rigidly control the processing technique relevant to such parameters. The tolerances of input parameters can be optimized to get the targeted qualified rate of a batch.At last, practical investigation is done to find how processing techniques are related to such selected important parameters. The conformity is well improved by strictly controlling these important techniques.