Research On Robust Predictive Control Algorithm Of Train Multirate Active Suspension

With the rapid development of the train, the control performance of suspension system can directly affect the stability and safety of train operation. Active suspension system can improve lateral and vertical vibration and currently it is a hot research subject for vibration and noise reduction. However, the existing research on suspension control technology often ignore the multirate phenomenon. So under the relevant background, robust predictive controller of multirate active suspension system was designed in this paper, and study on multirate active suspension control technology was carried out to optimize the damping property of the active suspension.During the operation, train is affected by external excitation input. American track spectrum was simulated to be the external disturbance of dynamic model. Taking into the factors account and in response to the multi-axis excitation, therefore, the dynamics model of active suspension system with the lateral-vertical 9 degree was established. The evaluation index of the suspension system comfort was calculated and the rationality of the model was verified.On the basis of the time-domain continuous model, discretization of single-rate suspension model was used to establish the multirate active suspension model by lift technique. Based on status and feedback of LMI optimization, research on the model of multirate active suspension system and robust predictive control algorithm can be carried out.Multirate state space model was used as predictive control model. Robust predictive controller was designed for train’s multirate active suspension system. By comparing the output response result of the vertical centroid, nodding angle and the acceleration of roll angular. The multirate system possesses better response performance that the single-rate one and its vibration damping effect is better than the single-rate one. Therefore, it proves the the validity of multirate system. With robust predictive control, the effect before using the multirate control and after is more than 3 times, which verifies the effect of the designed controller and to some extent verifies the advantages of robust predictive control for its real-time optimization features. Then the system’s observability and controllability was verified and the stability of robust was analyzed. Under the certain basic sampling period, by using the genetic algorithm, the sampling period of the multirate active suspension system was optimized and the control performance of train’s was optimized during the operation.Based on the active suspension system modeling and the design of robust predictive controller as well as simulation theory, in proportion, based on magnetorheological damper,active suspension system device can be development and vibration test can be carried out onthe test bench. The vibration effect of the test bench and control effect of the robust prediction algorithm to the vehicle body vibration are verified by the experiment. The single-rate and multirate system are compared and analysed via the vibration response frequency and the output characteristic curve, then the theoretical results was verified.