The 3DP Real-Time Motion-Control Computer

Abstract

Implementing advanced motion-control algorithms requires a computer which can satisfy the computational needs of the problem, a powerful development environment for programming complex and abstract ideas, and an open-architecture which gives the programmer full access to all of the system’s capabilities. Conforming to industry standards is also important for system integration with other vendors’ equipment.

We have developed a system — the 3DP controller — which satisfies these requirements. The 3DP has a unique processor architecture which exploits the intrinsic 3dimensional nature of kinematic and dynamic equations. The majority of computations in advanced robot control algorithms are for solving kinematics and dynamics. By exploiting the innate 3-dimensional characteristic of the target problem the 3DP achieves execution speeds many times faster than any existing processor.

The 3DP is a second generation robot control computer which improves on the ideas developed in the RIPS architecture [1]. It is an attached processor which plugs into a workstation’s VME bus. An optimizing C++ compiler lets the user program complex algorithms in a high-level object-oriented style, yet extremely efficient run-time code is produced. The user accesses the 3DP with familiar UNIX system calls, and the industry-standard VME bus allows the 3DP to communicate with other vendors’ products. Even though the user views the 3DP through UNIX, real-time program execution and external communication is not degraded by UNIX’s unpredictable response time.