Effects of Sensor Placement and Errors on Path Following Control of a Mobile Robot-Trailer System

In this paper, effects of sensor location and measurement errors on path tracking control of a mobile robot pulling a trailer are reported. A model for a two-wheeled robot towing a trailer is presented, followed by a state feedback controller designed to position the trailer along a path consisting of lines and circular arcs. An incremental encoder is used to measure the hitch angle between the robot and trailer. A combined GPS/IMU system is used to measure position and orientation of either the robot or the trailer (but not both). The choice of mounting location for the GPS/IMU system, and consequent effects on trailer path tracking performance are explored. The sensitivity of the system to hitch angle errors is also examined for both cases. It is shown that the system is less sensitive to errors in the hitch angle measurement when the GPS/IMU system is located on the trailer.