Learning A Risk-Aware Trajectory Planner From Demonstrations Using Logic Monitor

Xiao Li, Jonathan DeCastro, Cristian Ioan Vasile, Sertac Karaman, Daniela Rus

Keywords: Learning from demonstrations, temporal logic, trajectory planning, autonomous driving, real-time verification

Abstract: Risk awareness is an important factor to consider when deploying policies on robots in the real-world. Defining the right set of risk metrics can be difficult. In this work, we use a differentiable logic monitor that keeps track of the environmental agents' behaviors and provides a risk metric that the controlled agent can incorporate during planning. We introduce LogicRiskNet, a learning structure that can be constructed from temporal logic formulas describing rules governing a safe agent's behaviors. The network's parameters can be learned from demonstration data. By using temporal logic, the network provides an interpretable architecture that can explain what risk metrics are important to the human. We integrate LogicRiskNet in an inverse optimal control (IOC) framework and show that we can learn to generate trajectory plans that accurately mimic the expert's risk handling behaviors solely from demonstration data. We evaluate our method on a real-world driving dataset.