Attractive regions formed by the environment in configuration space: The possibility of achieving high precision sensorless manipulation in production

Abstract

One of the main purposes in robotic manipulation is to eliminate the uncertainty in the location of objects. So far, the controller system with sensory feedback has been used in most dynamic systems to eliminate the uncertainty of the system state. However, sensorless manipulation can also eliminate the uncertainty of the system state, which avoids problems caused by sensors. Recently, the approach on sensorless manipulation has drawn increasing attention and many important results have been presented. However, in general, it is believed that sensorless manipulation can only achieve low-precision or simple tasks that are greatly limited in their application areas. Stimulated by work in related areas, an interesting concept of 'attractive region in configuration space' was proposed. Through a unique method of formulation and utilization of the attractive region in the configuration space, (1) the strategy to achieve high-precision assembly in 3D without a force sensor and a flexible wrist was designed directly and (2) the available initial region from which an object can be grasped into a stable state with a certain gripper was obtained directly. These show that the strategy to achieve high-precision sensorless manipulation can be formed systematically through the formulation and utilization of attractive regions in configuration space, if the strategy exists. The work may also include the approaches on 'how to find the maximum attractive region' and 'when the attractive region exists'.