... task, and design the manip- ulator and end effector to be only as complex as will accomplish that task. Trial and error is the best method in many fields of design, and is especially so for robots. ... Motor and Motion Control Systems 13 the tolerance, wear, and compliance in the mechanical components between the carriage and the position encoder that can cause deviations between the desired and ... robots. Prototype early, prototype often, and test every- thing. Mobile robots are inherently complex devices with many interac- tions within themselves and with their environment. The result of...