Thomas E. Wheatley

Design principles for a real-time robot control system

The design of multiprocessor hierarchical robot control systems is examined from the application viewpoint. A concurrent communication and control algorithm is presented as the generic software component of the control system in an attempt to reduce the complexity and increase the reliability of the overall design. Some design principles that informally guarantee the correctness of the algorithm are proposed. These principles help at a lower level of design abstraction where the actual components of the computer system architecture need to avoid functional problems such as deadlock, starved processes, poor performance, and other design shortcomings

Configuration and performance evaluation of a real-time robot control system: the skeleton approach

The skeleton approach as applied to the NASREM multiprocessor robot control architecture is described. The skeleton approach creates the shell of a functioning real-time control system utilizing the actual hardware and operating system code without using actual application code. This is done by replacing the processing part of the application code with time delays. Parameterization of time delays, communication paths, message buffer lengths, and process allocation allows rapid prototyping of alternative system architectures. Actual system performance is measured to provide realistic data on computation and communication loads. The skeleton reporting facility provides quantitative assessments of system activity. To illustrate the use of this technique, the servo level of the NASREM hierarchy is modeled using a 5.0 ms cycle time on a multiprocessor system and compared with the actual system