The CLAPPER: a dual-drive mobile robot with internal correction of dead-reckoning errors

Presents a new approach to accurate and reliable dead-reckoning with mobile robots. The approach makes use of special properties of the author´s multi-degree-of-freedom (MDOF) mobile platform, in which two differential-drive mobile robots (called “trucks”) are physically connected through a compliant linkage. Using one linear and two rotary encoders, the system can measure the relative distance and bearing between the two trucks. During operation, both trucks perform conventional dead-reckoning with their wheel encoders, but, in addition, use information about their relative position to correct dead-reckoning errors. The author´s system, called Compliant Linkage Autonomous Platform with Position Error Recovery (CLAPPER), requires neither external references (such as navigation beacons, artificial landmarks, known floorplans, or satellite signals), nor inertial navigation aids (such as accelerometers or gyros). Nonetheless, the experimental results included in this paper show one to two orders of magnitude better positioning accuracy than systems based on conventional dead-reckoning