Effective manipulation for a multi-DOF robot manipulator in laboratory environments

Abstract

Robots are expected to enter human environments soon, and many challenging problems may then emerge when facing uncertain and varying environments. Among the challenges, one issue of great interest is how they can be effectively operated for task execution. If a robot is not to be controlled by detailed analysis and program coding, one appealing alternative is to provide a kind of manipulation system which enables the user to operate the robot naturally and efficiently. This idea has motivated us to develop an effective manipulation system for multi-degree of freedom (DOF) robot manipulators based on a 6-DOF haptic device. In this article, we focus on the laboratory environment, which is somewhat organized, but still demands sophisticated human manipulation. The proposed manipulation system, aimed for 3-D applications, provides two kinds of assistance. One is to enhance the linkage between the user and robot manipulator via the haptic clue. The other is to guide the movement of the user during task execution via a set of virtual tools, e.g., a ruler. We also propose a method for achieving smooth force rendering in manipulation, especially during the transition between two consecutive manipulations for guidance. For performance evaluation, this system is employed to conduct experiments in the chemical laboratory, which involve delicate and challenging maneuvers.