Integrating Planning and Scheduling in a CP Framework: A Transition-Based Approach

Many potential real-world planning applications are on the border of planning and scheduling. Consider a group of robots (like NASA’s Mars Rovers), that can maneuver over a designated area, perform soil tests, and can take pictures of interesting objects. There are many temporal and resource constraints that the robots have to satisfy while preforming any given set of tasks. For example, robots can only communicate via satellite within certain time-windows, some target objects are only visible within certain times, robots have limited battery power and batteries are solar powered, and each action (for example moving from one place to the other) requires a fixed amount of power etc. To achieve a set of goals (like testing soil of different locations and taking picture of different objects), the robots have to decide how to achieve those goals (planning choices) and also they need to achieve these goals without violating any temporal and resource constraints (scheduling choices). For any automated system, that is able to handle the complexity of this type of problems, it is essential to integrate planning and scheduling techniques.