Interactive Operation Of Unknown Constrained Mechanisms With Use Of Robot Manipulator

Among the various kinds of the assistive robots, assistive manipulators are one of the most important classes. Acting as the replacement or semi-replacement of the arms of the nursing people, assistive robots are supposed to help them perform some certain tasks, manipulate various daily objects or provide the old/disable with some customized rehabilitation exercises. This paper researches the interactive operation between manipulator robot and the environment. And design a controller to operate the constrained mechanism, including knob grasping and operation of the constrained mechanism. In the daily life, a contact between the manipulator and the constrained mechanism could be of many kinds, a typical example is opening/closing a door or a drawer. These kinds of operation include two aspects: knob grasping and mechanism operation. In order to grasp the knob of the constrained mechanism, this paper proposes a grasping method based on multi-vision gravitational field; and proposes a method based on dynamic interactive control to operate the constrained mechanism.At the aspect of the aided grasping, this paper proposes the image-based multi-vision gravitational field method to solve the problem that the 3-D position estimated by eye-in-hand camera is not enough accurate and the vision becomes fuzzy when near to the constrained mechanism. This paper designs the vision controller and dynamically adjusts the control weights of eye-in-hand camera and eye-to-hand camera according to distance information. At the aspect of unknown constrained mechanism operation, this paper proposes based on dynamic interaction control algorithm, which does not need to know the model of the constrained mechanism and the position and orientation of the constrained mechanism. This paper draws the concepts of dynamic selection matrix and driving-axis, and determines the constrained frame and dynamic selection matrix according to the force/torque information fed by 6-D force/torque sensor. The diving-axis and non-driving-axis are decoupled in the constrained frame, and motion control is used in the diving-axis because the diving-axis is the direction of the constrained motion; to promise the compliance of the manipulator robot, impedance control is adapted in the non-driving-axis.This paper makes some interactive experiments between manipulator and environment based on the service manipulator robot designed by my lab to assist the elderly/disabled people. The grasping and operation of the unknown constrained mechanism are done by manipulator using the environment information fed by the vision and force/torque sensors. At the aspect of vision aid, the knob is grasped by the multi-vision gravitational field method under the set of an eye-in-hand camera and an eye-to-hand camera. The validity of the method is verified by the experiment of grasping the knob of door A. At the aspect of unknown constrained mechanism, the operation objects are door A, door B and the drawer. And some experiments are done to verify the validity and adaptability of the operation algorithm.