Safety Control Synthesis with Input Limits: a Hybrid Approach
For control systems requiring safety guarantees without constant intervention, this hybrid approach offers a practical solution, though it is incremental in nature.
The paper introduces a hybrid safety controller that enforces state and input constraints only when necessary, preserving transparent operation within a safe region defined by a Min-Quadratic Barrier function. The method is demonstrated in simulation-based examples.
We introduce a hybrid (discrete--continuous) safety controller which enforces strict state and input constraints on a system---but only acts when necessary, preserving transparent operation of the original system within some safe region of the state space. We define this space using a Min-Quadratic Barrier function, which we construct along the equilibrium manifold using the Lyapunov functions which result from linear matrix inequality controller synthesis for locally valid uncertain linearizations. We also introduce the concept of a barrier pair, which makes it easy to extend the approach to include trajectory-based augmentations to the safe region, in the style of LQR-Trees. We demonstrate our controller and barrier pair synthesis method in simulation-based examples.