The whisker sensor and the transmission of multiple sensor signals

摘要

First, a new type of proximity sensor called a 'whisker sensor' is proposed which consists of an elastic whisker and a sensing system mounted at the base of the whisker. The sensing device detects any minute flexure of the whisker when it touches an object during motion of the robot. The recommended material for the wisker is a TiNi shape memory alloy with pseudo-elasticity. For signal detection, both the so-called bit- and analogue-type detectors are shown to be realizable. The bit-type whisker sensor can be constructed in a compact form with a simple and solid mechanism so that it is economical, can be used in a dangerous environment, and as many as necessary can be mounted on the robot. The analogue-type whisker sensor, based on a photo-interrupter for the sensing system, has been experimentally assembled and its capability for detecting objects with a good degree of accuracy is demonstrated. Second, the importance of installing multiple tactile or proximity sensors on a robot, as in insects or mammals, is pointed out. The problem of minimizing the number of signal transmitting wires is discussed. To cope with this problem, two methods are proposed: a ladder connection method and a local preprocessing approach. The effectiveness of these two methods is verified by two experiments, including an off-road walking test using a quadruped walking vehicle model.