Real-time issues in advanced robotics applications

The aim of this paper is to discuss some important real-time issues involved in the design of complex robotic applications. In particular the problem of evaluating why and when a robotics application needs real-time computing is discussed first. The second issue concerns the definition of time constraints for each task of the robot. We show how time constraints, such as periods and deadlines, can be derived from the application, even though they are not explicitly specified in the requirements. As a third issue, we describe a general hierarchical control architecture, which can be built on top of a real-time system, to greatly simplify the development of complex robotics applications having real-time requirements.