Measurement system and evaluation approach for straightness error of valve sleeve inner hole

The inner hole characteristic and evaluation requirement of valve sleeve in slide valve is studied, and a new pneumatic measurement approach for axis straightness error of valve sleeve inner hole is put forward based on differential pressure measuring principle. According to the pneumatic nozzle scanning principle and the characteristic of the acquired points in the measuring process, a new evaluation approach for spatial straightness error based on the improved genetic algorithms (GAs) combined with the least square method is presented considering the minimum zone criterion. The corresponding pneumatic experiment and straightness error calculation is carried out. Experiment and calculating results show that the developed pneumatic measuring system has high resolution and accuracy, and the evaluation algorithm proposed in this paper is robust, which has high efficiency and reliable computational results. The developed system and evaluation approach satisfy absolutely the strict requirement of measurement precision and automation for the straightness error of valve sleeve inner hole.