A B S T R A C TThe IRIS Facility is a modular, reconfigurable and expandable robot system to be used for experiments in grasping, manipulation and force control. The baseline layout of the Facility will have two manipulators with four rotary joints each. Each manipulator can be easily disassembled and reassembled to assume a multitude of configurations. Each joint is driven by d.c. brushless motors coupled with harmonic cup drives and instrumented with position, and torque sensors. A six d.0.J forcdtorque sensor is mounted at the tip link. Additional manipulators with different joint layouts will be added in the future.The real-time controller of the IRIS Faciliry has also been designed to be modular and expandable. It is based on a nodal architecture with a PC-486 host and an AMD29050 co-processor as the CPU of each secondary node. Each node is capable of controlling 8 joints at I kHz while executing over lo00 FP (Floating Point) operations per joint in each sampling interval. This paper describes the design of the IRIS Facility and its functional capabilities. I n addition, the rationale behind the major design decisions is given.

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Abstract. In this paper, we address the topic of numerical computation in a system of multiple manipulators, one which has received scant attention despite a great deal of research in development of control schemes and the proliferation of similar work on single manipulator systems. Different approaches to computations in kinematics, statics and dynamics of multiple manipulator systems are studied and compared. The results show that significant savings in computational count can be achieved through customization of models. A systematic approach to customization is also described herein.

Non-holonomic constraints characterize robot Aystems in rolling contact with the environment as well as space manipulators. In this paper, we address the issue of stability of non-holonomic systems. In the past, it has been shown [Neimark and Firfaev, 19721 that an equilibrium manifold, rather than an isolated equilibrium point, exists for these systems. We show herein that Lyapunov's second method and La SalleS Theorem of Invariance can be adapted to study the stability of this manifold. Specifically, the Lyapunov function must be positive definite with respect to the equilibrium manifold and its derivative must vanish identically only thereupon. The example of the rolling vertical disc is used to illustrate the analysis.

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