Reactive objects in a task level open controller

The authors present some design issues for a task-level controller based on a specific control approach. The achievement of a robotic application requires the use of a large set of cooperating devices such as manipulators and sensors. An application is performed by scheduling several actions of the system. Each action is modeled with a functional aspect (control law) and a behavioral one (reactions on events). These two aspects are combined in a single object, the robot-task. An object-oriented approach was used to model these actions. The synchronous language Esterel was used both to program an application at the end-user level and to program the behavioral part of the robot-tasks at the control level. The main design issues of a real-time controller able to implement and perform these actions are outlined