For HTN planning, we formally characterize and classify four kinds of problem spaces in which each node represents a planning problem or subproblem. Two of the problem spaces are searched by current HTN planning algorithms; the other two problem spaces are new. This enables us to provide: • Sufficient (and in one case, necessary) conditions for finiteness of each kind of problem space. The cond...

Multirobot path planning and task assignment are traditionally treated separately, however task assignment can greatly impact the difficulty of the path planning problem, and the ultimate quality of solution is dependent upon both. We introduce task reassignment, an approach to optimally solving the coupled task assignment and path planning problems. We show that task reassignment improves solu...

Construction operations can be categorized as either routine and repetitive or unique and complex. The means of developing an understanding of operations in each category differs. An understanding of routine and repetitive operations is best developed through analysis of field operations. Unique and complex operations by their very nature have not been constructed in the field. Therefore, an un...

AI planning techniques are beginning to find use in a number of practical planning domains. However, the backward-chaining and partial-order-planning control strategies traditionally used in AI planning systems are not necessarily the best ones to use for practical planning problems. In this paper, we discuss some of the difficulties that can result from the use of backward chaining and partial...

This paper describes the development of a system for simultaneous planning and execution of surgical operations in the cranio-maxillo-facial area. Simultaneous planning and execution is the process of taking an implicit task description, planning a sequence of explicit execution commands (e.g. for robots) and monitoring their execution. As the execution planning process is run completely on-lin...