Ro-To-Go! Robust Reactive Control with Signal Temporal Logic
For roboticists using STL-based control, this work improves decision-making in MPC by removing history dependence, though it is an incremental improvement over existing methods.
The paper introduces Ro-To-Go, a new quantitative semantics for Signal Temporal Logic that isolates suffix trajectory contributions, enabling more effective Model Predictive Control. Experiments show higher success rates compared to traditional STL robustness.
Signal Temporal Logic (STL) robustness is a common objective for optimal robot control, but its dependence on history limits the robot's decision-making capabilities when used in Model Predictive Control (MPC) approaches. In this work, we introduce Signal Temporal Logic robustness-to-go (Ro-To-Go), a new quantitative semantics for the logic that isolates the contributions of suffix trajectories. We prove its relationship to formula progression for Metric Temporal Logic, and show that the robustness-to-go depends only on the suffix trajectory and progressed formula. We implement robustness-to-go as the objective in an MPC algorithm and use formula progression to efficiently evaluate it online. We test the algorithm in simulation and compare it to MPC using traditional STL robustness. Our experiments show that using robustness-to-go results in a higher success rate.