Study of odor compass

A new sensing system to navigate a human or a mobile robot to an odor source is proposed. The system is called an “odor compass” since it continuously points toward an odor source by rotating a directional probe with plural gas sensors according to their responses. Sufficient working speed and convergence stability of the compass direction for practical use have been achieved by refining the control algorithm in spite of the slow and fluctuating sensor responses. A state equation is used to describe the sensor dynamics, and its parameters are estimated by the recursive least squares estimation. As a result, the direction toward an odor source has been successfully obtained from the estimated state equation. The measurement time has been reduced to 20-30 s from 60-180 s in the preliminary experiments described in the previous papers, and the deviation of the compass direction has also been suppressed to be 5° from 20-30°