Personal Dead-Reckoning System

Dr. Lauro Ojeda

University of Michigan

Mobile Robotics Lab – Mechanical Engineering Department

The Personal Dead-Reckoning system (PDR), measures and records continuously the walker’s speed and travel distance with an error of <2% of distance traveled. There is no limitation to the total travel distance or to the duration of the experiment: After 5 meters or 5 kilometers, the measurement error remains always <2% of distance traveled. The PDR does not require any external beacons, markers, retroreflectors, or cameras. Rather, it works with a 6-axis inertial measurement unit (IMU) attached to the walkers foot. While such IMU-based systems have been developed in the past, double integration of small errors such as bias drift make them unusable for walks of more than a few seconds. In contrast, thanks to our novel techniques, the accelerometers in our PDR do not accumulate significant errors, regardless of the duration of the experiment. In addition, our PDR works equally well with different gaits, including walking, jogging, or dancing, for that matter. Lastly, the PDR does not require calibration or any kind of adaptation to the user. Any user can strap a PDR onto her footwear and start walking. Besides measuring the travel distance the PDR can also determine the position of the walker in x-y-z coordinates, relative to a known starting position. We have successfully tested this system walking through 3-D environments with staircases several floors high.

Friday, September 29, 2006

3:30 – 4:30 p.m.

1500 EECS