Multi hydraulic motors synchronized control based on field bus with FlexRay protocol

This paper constructs a field-bus control network with FlexRay communication protocol for the multi hydraulic motors synchronized system, which can provide network transmitting with deterministic time-constraint by its MAC methods of TDMA and FTDMA. The topology architecture of the control network is proposed and the logical model of a FlexRay node is hierarchically analyzed. The adjacent cross-coupling strategy is adopted for synchronized control, so the real-time data interaction across the network is needed to be guaranteed by designing the configuration of the network and choosing the sampling time of the control system. Then the data flow among nodes and the static scheduling of the FlexRay network are presented. We have analyzed the loop delay characteristics of a control cycle, considering the sampling period, the data transmitting time and the control law computing time, and have established the dynamic model of a field node-hydraulic motor. A discrete-time SMC algorithm with the exponential reaching raw is proposed based on the adjacent cross-coupling strategy. Finally, the simulation results of a four hydraulic motors synchronized control system in TrueTime, a toolbox in Matlab Simulink for the simulation of the networked control system, have proved the effectiveness of the proposed model and control strategy.