Polishing Task Research Articles

Compliant motion using a mobile manipulator: an operational space formulation approach to aircraft canopy polishing

The operational space formulation provides a framework for the analysis and control of robotic systems with respect to interactions with their environments. In this paper, we discuss its implementation on a mobile manipulator programmed to polish an aircraft canopy with a curved surface of unknown geometry. The polishing task requires the robot to apply a specified normal force on the canopy surface while simultaneously performing a compliant motion keeping the surface of the grinding tool tangentially in contact with the workpiece. A human operator controls the mobile base via a joystick to guide the polishing tool to desired areas on the canopy surface, effectively increasing the mobile manipulator's reachable workspace. The results demonstrate the efficacy of compliant motion and force regulation based on the operational space formulation for robots performing tasks in unknown environments with robustness towards base motion disturbances. The mobile manipulator consists of a PUMA 560 arm mounted on top of a Nomad XR4000 mobile base. Implementation issues are discussed and experimental results are shown.

Polishing Robot Using Joystick Controlled Teaching

In this article, an impedance model following force control, which uses a position/orientation compensator based on joystick-taught data, is proposed for an industrial robot with an open architecture controller. The present method has two characteristics: it is easily applied to the task where an industrial robot polishes an object with desired contact force and orientation and does not need conventional complicated teaching. The effectiveness and promise of the proposed method are demonstrated through experiments in a polishing task using an industrial robot FS-30.

A Teaching System of Force Control Using a Game Joystick for a Polishing Robot.

In this paper, a teaching system of force control is proposed for a polishing robot using a game joystick. The teaching process is as follows: first, a zigzag path considered according to both sizes of each work and polishing tool is prepared; next, the polishing robot, in which an impedance model following force control method is incorporated, profiles the surface of the work using the zigzag path. The operator has only to control the orientation of the polishing tool using a game joystick so that the tool and work can be in contact each other, keeping the desired relation of position and orientation. Since the impedance model following force controller keeps the contact force to be a desired value, the operator has to give no attention to a sudden over-load or non-contact state. The desired trajectory is automatically obtained as the data including both continuous information of the position and orientation along the zigzag path on the object's surface. After all, the robot can achieve the polishing task without any assists of the operator by referring the acquired trajectory.

Optimum Machining Conditions for Mirror Polishing of Aluminum Alloy Using a Robot.

Using robots in precision machining fields, such as grinding and polishing, is becoming more prominent in recent years. This paper presents original research results of aluminum alloy surface polishing using a rubber polishing disk in a robotic polishing system. A rotary hand-polishing system is held by the actuator of a six-axis articulated robot to perform the polishing task. The workpiece is an aluminum alloy block fixed on a piezo-electric type dynamometer. For finding the optimal tool angle to obtain the best polished surface, some polishing experiments were carried out using various tool angles. The effects of the number of polishing strokes on the surface roughness and depth of machining have been also estimated. Finally, calculated results and experimentally obtained results of a multi-stage polishing were compared. The obtained experimental results are useful for finding the optimum machining conditions for making an autonomous robotic polishing system.