Planning for parts-picking tasks by using multi-sensor visual system

In a parts-picking system, it is frequently required not to pull down a stack to avoid damage of products and to improve manipulation performances. Pulling down a stack is caused not only by collision between a manipulator and parts but also by picking a part that supports another. To keep away from the pulling-down side effect, we constructed a sensor system for the parts-picking operation. The system checks if picking a part may make other parts unstable and estimates the possibility of the collision. Taking them into account, the system determines the order of the picking operations among parts that can be reliably picked. Results of experiments show that, using the sensor system, we can largely reduce the possibility of the pulling-down occurrence