Comparison of LTI and event-based control for a moving cart with quantized position measurements

Traditional linear time-invariant (LTI) control design assumes that measurements are taken at regular time intervals and have independent additive noise. A common practical case that violates this assumption is the use of encoders that give quantized position measurements; when the quantization is appreciable the measurement noise is far from LTI. This paper develops a simple event-based controller based on simplifying a joint maximum a posteriori estimator, which is applied to a moving cart with quantized position measurements. The payoff for implementing the somewhat more complex event-based controller is to drastically reduce the effect of quantization noise in the experiments. A sequence of simpler to better adapted controllers are described and compared according to experimental performance and implementation complexity.