Version 1.0, August 31, 2001, Copyright, Hugh Jack 1993-2001
There are a number of different ways to classify the robotics problems. Various features of a problem may determine which type of path planning strategy will work best. Two fundamental classifications suggested by Fu, Gonzalez, and Lee [1987, Pg.150] are Obstacle Constraint and Path Constraint. Obstacle Constraints indicate that there are some points in space which are already occupied, and are not free for the robot to pass through. Path Constraints are usually provided as points on a path which the robot must follow. From these two suggestions there is a control strategy diagram which may be drawn,
Figure 1.1 Control Strategies for Manipulators [Fu,Gonzalez & Lee,1987]
These basic strategies form the basis for most approaches to robotic path planning. Positional Control is a simple motion controller using joint interpolated motion, or point to point motion. Path Tracking is moving through a prespecified set of points on a path. All of the strategies in this diagram affect the methods used to plan paths, thus from this point it is best to discuss some requirements of the system.