Laser rangefinder calibration for a walking robot

The author presents techniques for calibrating scanning laser range finders to legged robots. The procedure accommodates two scanners, one manufactured by Erim and the other by Perceptron, and two walkers, a one-legged robot and a six-legged robot. The technique acquires two sets of corresponding three-dimensional points and identifies the rigid transformation that maps one onto the other with least squared error, i.e. it solves the absolute orientation problem. Experimental results are reported with the two different scanners and vehicles. For the Erim and the one-legged robot, the technique achieves an accuracy of 6-12 cm with a precision no lower than 2-5 cm. For the Perceptron and the Ambler, the accuracy is 2-7 with a precision no lower than 2-5 cm. These results have proven to be satisfactory for constructing terrain maps and using them to select footholds during rough terrain walking experiments