Research On Predictive Control Algorithm Of High-speed Train Multirate Active Suspension

Safety, smoothness and comfort are constant goals of high-speed railway transportation.With the improvement of running speed, the transportation service quality of train runningsecurity stability and ride comfort would be even more dependent on the vibration attenuationproperty of suspension system. It means, only higher performance standards and requirementsof suspension system could be adapt to the rapid development of railway. Active suspensioncontrol technology is the effective way to improve vertical and crosswise comfort level oftrain, which is the research emphasis for relevant aspect of vibration attenuation and noisereduction. However, in the past research of suspension system, the difference of samplingfrequency in each part and the time delay phenomenon which is objective existence of systemare always be ignored. This paper based on related research background, taking time delayand multirate phenomenon to the active suspension system of high speed train, doing researchof active suspension control technology, to design controller for multirate suspension system,thereby vibration damping performance of the suspension system better function in theincrease of train’s speed.Based on the track alignment irregularity and track longitudinal irregularity, a ninedegree of freedom high speed train continuous-time active suspension system dynamicsmodel was built, which include in vehicle body roll angular acceleration, leading and trailingbogie roll angular acceleration, etc, three degree of freedom transverse vibration and vehiclebody vertical acceleration,vehicle body nod angular acceleration,leading and trailing bogievertical acceleration, leading and trailing bogie nod angular acceleration, etc, six degree offreedom vertical vibration. After discretization, lift technique was used, and time delay wastaken to system, then the discrete single rate and multirate with time delay suspension systemmodel was get. To analyze the vibration output of system through simulation with passivesuspension(without control), the results showed that time delay would be influenced vibrationattenuation property and result in the decrease of system response speed, multirate have betterattenuation property than single rate system.Orthonormal basis function-Laguerre function model predictive control (MPC) was Usedto design corresponding predictive controller for high speed train continuous-time, discretesingle rate, discrete multirate and multirate with time delay active suspension system,respectively. Simulation and analysis was carried out for active suspension closed-loopcontrol system, the better control property of multirate than single rate system and the harm oftime delay to response speed and control effect of system was explained by the simulationresult of vehicle body vertical acceleration, nod angular acceleration and roll angular acceleration output response. Optimum control was compared with predictive control throughroll vibration control output of active suspension system, the superiority of predictive controlwith real time optimization characteristic was verified after analyzing the control effect of twocontrol strategy.Based on vehicle active suspension vibration attenuation test bench withmagneto-rheological damping, the total experimental system was built with subsystemsinclude in test bench, outside incentive system, measurement and control system, and U/Icircuit conversion system, etc. Predictive control algorithm was added to do experiments ofvibration control, the damping effect of test bench and effectiveness of predictive controlalgorithm was verified. The difference between single rate and multirate active suspensioncontrol system was compared and analyzed from the speed of vibration control and property,the result accorded with the theory analysis in general.