The Design And Realization Of Air-Bearing Test-bed Control System

Air-bearing test-bed is bound with the measurement of the inertia instrument. In fact, Its accuracy decides the quality of the Gyro and Accelerometer. Nowadays It is clear that the development of Micro-satellite has high connection with Air-bearing test-bed due to its small friction which can provide an ideal approximation of space environment on the ground.This research comes from a project. Based on the process to realization of the control system ,the thesis focus on two problems abstracted from those encountered in design :One is the smooth characteristic of input signal.Generally speaking , actual physical systems set a limitation on output such as velocity ,accelerator ,jerk. A S-curve motion planning method is employed to produce more smooth velocity curve than that by Trapezoidal method popular in industrial area. The requirements for the stability of velocity in the test-bed system are high.In this project ,with the velocity feedback loop involved ,the fluctuation of velocity signal is suppressed into an acceptable zone.It is more convenient that if there is an algorithm which can filter the high-frequency component of the input signal out,with the low-frequency left which is easier for the control system to trace . The test-bed limitation is taken into consideration ,based on that , a four-order trajectory planning is completed. The effect can be obvious from the simulation between S-curve motion profile and trapezoidal method.The other is the model uncertainy.In fact, model uncertainy reflects the dynamic aspects of the object and hampers the application of the control strategic grounded on normal model. It is natural that the method used has a weakness dependent upon the model. A model-free controller based on the I /O driven is adopted to compensate it . A possible theory model is built on tailor expansion. Upon that ,the convergence is took into account and the validity of the algorithm is analyzed breifly. Finally,the initial parameters for IFT is the same as that for manual tuning. The comparison between IFT and manual tuning is presented. A conclusion derived from the simulink is that the performance by IFT is superior to that by manual tuning.The thesis implements the control system software based on the windowsRTX, designs of the butterworth filter to cancel the noises on velocity singal. It figures out how to measure the rotational inertia , gives the friction torque and the parameters for the Air-bearing.