Study On The Design And Experiment Of Permanent Magnet Linear Direct Current Actuators For The Active Suspension Of Automobile

With the social development, improvement of people's living standards, the rapid development of speedway and increase of vehicle velocity, people have made more demands on the comfort and security of automobiles. Suspension system is one of the most important parts in the whole automobile. Its performance influences directly on such characteristics of auto as ride comfort stability, safety and longevity, etc. The effect of the traditional passive suspension system is limited due to the contradictions between the riding and handling performance. For semi-active suspension system, it cannot provide active force and just consume energy, thus its performance is far less than that of the active suspension system. In the research active suspension system of the vehicle, there is a great achievement about the control algorithm, but relatively lack in the key part of the active suspension system namely actuator. Based on this, this thesis is studying the actuator using in the active suspension of vehicle.In this paper, the application of vehicle dynamics, combined with optimal control theory to establish the state space model seven degrees of freedom of vehicle vibration system and study on the correlations of the simulation, it proposed the active suspension actuators main operating parameters.For vehicle active suspension actuators key components and actuators design objectives, systematic access a variety of vehicle suspension application of actuator and on this basis, considering the processing cost and test prototype can be implemented. Chosen as the theoretical basis of the magnetic induction law, designing a linear direct current (DC) actuator using in the active suspension of automobile, and studying on the correlations of the simulation analysis and experiment.According to Linear DC actuator based on research results, on the permanent magnet linear DC actuator structure detailed design. Subsequently, using advanced finite element model simulation software Flux on the permanent magnet linear DC actuators simulation analysis and calculation, discussion on the structural parameters and the supply voltage of actuators on the electromagnetic force impact law.On the permanent magnet linear DC actuator drive control system under mathematical model was deduced and analyzed, given the dynamic structure of closed loop control system. On this basis, the proposed control system uses a digital-analog mixed-double loop (position loop and voltage loop) cascade control mode. In order to achieve high accuracy position control to meet the needs of real-time control voltage loop, while ensuring that the voltage of the inner and the position of outer loop have sufficient bandwidth to enable closed loop control system to have fast dynamic response.On the permanent magnet linear DC actuator of control circuit mainly includes battery, DC voltage Buck converter and H-bipolar type, voltage sensors, force sensors, input and output signals, permanent magnet DC linear actuators, ECT... In order to establish a simple test platform, the actuators were often related tests of strength. Test by test, test results show that the electromagnetic force actuators control system to meet the active suspension actuator electromagnetic force requirements.The whole study proved that the design of actuators for power generated to meet the design requirements; Simulation results also showed that this design of permanent magnet linear DC actuators can improve vehicle ride and handling stability.