Shield-Based Safe Control with Compensation of Computation Delays of Nonlinear Discrete-Time Systems

Abstract

We consider a nonlinear discrete-time system and a control specification including safety properties. In general, there exists a computation delay to compute a control input in a controller and the delay degrades control performances. To compensate the computation delay, we propose a safe controller using Mita's method and the shield synthesis, where the satisfaction of the safety properties is decided using a high-order control barrier function. First, we show an effect of the computation delay on the relative degree of the system. Next, we show the reduction of the number of functions that specify the high-order control barrier function. Finally, we propose a safe controller consisting of a predictor, a controller, and a shield. Then, we illustrate the proposed method on safe control of mobile robots.