Research On Linearity Correction Algorithm Of Displacement Sensor In Servo Mechanism And Processing Experiment

Precise potentiometer is a feedback component used in servo mechanism of aerospace field, and its performance determines the accuracy grade of control system. It is one of the key components of servo system. The production of precise potentiometer is backward in technique in our country, reflects in machining algorithm and process procedure. The first is inaccurate of the algorithm, as a result, the quality of production backs on the operation experience of workers. The second is backward of machining equipment and technology, which is inaccurate and not automate in machining.The main indicator of precise potentiometer is non-linear error. This thesis proposed a new correction algorithm to decrease its non-linear error. This algorithm based on two basic principles: potentiometer partial voltage principle, and total resistance feedback principle. Before machining, we can calculate the amount of machining accordance with the voltage measured before machining. As the contact resistance between brush and carbon film has no affection to the voltage from potentiometer, the machining amount calculated form voltage is more accurate than resistance measured straight. Feedback Principle based on total resistance makes the feedback parameters avoid the affection of vibration during machining, which also increase the accuracy of machining.Automatic processing equipment can improve the machining precise and efficiency of precise potentiometer. This thesis designed the mechanism and control circuit, using industrial control computer to control each component. All those work together to finish the automatic machining of precise potentiometer, providing the equipment support of mass production.Software of "Precise Potentiometer Automatic Measurement and Correction System" was written with Visual C++6.0. Using multi-threading technology, it was a modular design of each control unit. In the module of continuous processing, multi-axis control was given out under the same address, achieving the goal of continuous process. The software was also designed to realize the function of data processing, graphical display and printing, having a good production value.A series of experiment was given at last. The effect of measurement and machining was detected under different parameters, and a best result was chosen out. Experiment of measurement and machining was done under the parameters related above, and the experimental results proved the correctness of correction algorithm, hardware and software.