Implementation of RCCL, A Robot Control C Library On A microVAX II

Abstract

The robot control C library (RCCL) is a high-level robot programming system developed at Purdue University as a result of research funded by the National Science Foundation and the French CNRS. RCCL enables a programmer to employ a set of system calls to specify robot manipulator tasks. The system provides flexible geometry kinematic transforms, hybrid force and position control, updatable world representation, functionally defined motions, and portability. RCCL allows for position matrix transform operations and the generation of robot trajectories in joint or Cartesian modes. It is intended to overcome the limitations of dedicated robot controller languages. For proprietary commericial robot languages like VAL, the fact that source code is not available rules out the possibility of modifications required to develop advanced control algorithms. In contrast, RCCL offers the major advantages of modifiable source code, sensor-oriented control, transportability between manipulator configurations and host computers, and computational speed necessary to execute advanced control algorithms necessary for real-time operation. In cooperation with JPL, RCA is completing RCCL implementation on a DEC microVAX-II as a high-level controller for the PUMA 762 robot, with minor changes to JPL's Berkeley 4.2 UNIX operating system. Using the same operating system, JPL plans to implement RCCL on a micro-VAX for their PUMA 560. These installations provide essentially unlimited memory, an efficient programming language for software development, and accessible source code that makes possible the real-time capability to meet the evolving needs of robot control technology. The Robotics Laboratory at McGill University provided consultation and direct support. The Laboratory successfully implemented RCCL on a VAX 11/750 for their PUMA 260 robot.