Future Research Directions

A number of desirable extensions to the current implementation of the PDO/EPB representation have been identified in the last two chapters. These include:

• Inclusion of order of magnitude information, and even optional numeric information, in the partial distance ordering.
• Partial ordering of angles, rather than using a simple quantity space.
• Integration of the system for reasoning about sliding (currently using the ASSF representation) with the free space motion reasoning system.
• Extension to three dimensions.

The presently described reasoning system can also be extended to become more useful either as a basis for qualitative physics, or for robotic reasoning:

• As a qualitative physics system, it would require a more explicit representation of process.
• A more complete investigation of qualitative reasoning as a basis for task-level programming would be particularly interesting, but would eventually require an interface to a real robot.
• The fastener analysis problems mentioned in the introduction to the thesis as a challenge to current technology in robotics may well benefit from qualitative reasoning, but fasteners, being real mechanical objects, could be more difficult to describe qualitatively than the ``blocks world'' objects of my examples.

Qualitative spatial reasoning is a feasible approach to a number of problems in artificial intelligence. With further refinement, the methods described in this thesis should prove useful to both robotics and qualitative physics.