Robot machining accuracy control based on terminal closed-loop compensation

Industrial robot has gradually become the core component of modern manufacturing industry because it has advantages of high efficiency, flexibility and large working space. However, the characteristics of weak rigidity and multi-axis linkage of industrial robots lead to poor positioning accuracy and reduced motion precision, which is difficult to meet the requirements of high-quality manufacturing. Therefore, a terminal closed-loop compensation system was constructed, which is composed of KUKA robot, end effector and laser tracker. Then, a comprehensive evaluation index considering multiple precision factors was put forward, and the prediction model of this evaluation index under different process parameters was established by using grey correlation method. Results from multi-process experiments showed that the surface roughness, flatness, cylindricity, roundness and hole position error were reduced by 18.9%, 92.1%, 46.5%, 53.9% and 31.8% respectively after closed-loop compensation.