A case study of performance improvement in extremum seeking control via fractional-power feedback

In this paper, a new strategy is proposed for the nonholonomic unicycle to seek the source of a scalar signal. Based on the classical extremum seeking algorithm, the vehicle adopts fractional-power control and logarithmic measurement in order to seek the source faster in a wider region. The sensor assembled on the vehicle measures signal strength at its current position. Then, the high-pass filter eliminates the “DC component” of the signal of logarithmic form. After handled by fractional-power control, the signal is involved in the modulation and demodulation with the periodic perturbations. Finally, it acts as the forward velocity to steer the vehicle to the source. The simulation results demonstrate that the proposed technique achieves a satisfactory level of convergence range and fast tracking, especially under the condition that the initial position of the vehicle is far from the source.