反应堆压力容器检查机周向旋转臂的精度修正

反应堆压力容器检查机(reactor pressure vessel inspection machine,RPV检查机)周向旋转臂的精度影响在役检查中超声数据的质量。分析了回程误差在齿轮传动的位置伺服系统中对精度的影响。给出了一种回差修正方法:依据实际测量数据计算回差值;设置换向阈值以避免由于系统中微小颤动导致误判断;逐次分解回差值,防止修正影响系统稳定性。针对RPV检查机的周向旋转臂应用该修正方法,在不影响系统的稳定性、不产生超调的前提下,实现了提高旋转臂精度的目的。通过对修正前后超声数据对比,验证了该方法的有效性。

The Precision Improvement to the Reactor Pressure Vessel Inspection Machine

The accuracy of Reactor Pressure Vessel (RPV) inspection machine affects the ultrasonic data quality. The factors affecting the accuracy in the gear-driven servo system were analyzed, concluding that the backlash is the most important one. The second part provided the method to make backlash correction, and the flowchart was given. There are three key points. The first one is the constant backlash distance, which can be got through the measurement. The second is the setting of a threshold, which determines that a reversal has occurred and the backlash distance must be introduced. Also, the rate at which backlash is introduced to produce smooth transitions has been given. The backlash correction method has been applied in the rotation arm of RPV inspection machine. The result showed its accuracy had been improved.