Source Seeking With Very Slow or Drifting Sensors

Abstract

Slow sensors arise in many applications, including sensing chemical concentrations in tracking of contaminant plumes. Slow sensors are often the cause of poor performance and a potential cause of instability. In this paper, we design a modified extremum seeking scheme to account and exploit slow sensor dynamics. We also consider the worst case, which is sensor dynamics governed by a pure integrator. We provide stability results for several distinct variations of an extremum seeking scheme for one-dimensional optimization. Then we develop a design for source seeking in a plane using a fully actuated vehicle, prove its closed-loop convergence, and present simulation results. We use metal oxide microhotplate gas sensors as a real world example of slow sensor dynamics, model the sensor based on experimental data, and employ the identified sensor model in our source seeking simulations.