Silvermate hardware platform   Simulation model of Silvermate

We are currently developing the motion planner for the Silvermate mobile manipulation system (see Figure) under development at the Center for Intelligent Robotics, Korea Institute of Science and Technology (KIST). The current prototype consists of a seven degree-of-freedom arm mounted on a nonholonomic wheeled platform, together with a three-finger hand. The Silvermate is intended to function in human environments, assisting the elderly in various tasks while avoiding collisions with static and moving objects in a dynamic and uncertain environment. Autonomous mobile manipulation systems like the Silvermate require the integration of both planning and control at several levels, particularly if they are to work in real-time, relying on noisy sensors in environments with inherent uncertainty.

We are currently developing a motion planner that extends the elastic roadmap framework developed by Oliver Brock: new algorithms are being developed to, among others, generate coordinated motions for the arm and nonholonomic base, and the simultaneous handling of dynamic posture and compliance constraints during task execution. The simulation shows the Silvermate maneuvering through an environment cluttered with both static and dynamically moving obstacles, all the while balancing a tray on its hand. The milestones are upated in real-time at a rate of 10Hz on a Pentium XX MHz computer, while the potential field-based control law is updated at a rate of over 100Hz. A prototype with dual arms and a holonomic base is currently being developed, with plans to eventually execute closed chain, cooperating manuevers in compact, dynamically changing cluttered environments.

Motion planning and control for the silvermate using the elastic roadmap framework