Attainment Regions in Feature-Parameter Space for High-Level Debugging in Autonomous Robots
This work addresses the challenge of controller debugging for autonomous robots in safety-critical tasks, offering a method to simplify adaptation and explanation in complex domains, though it appears incremental as it builds on existing performance function and Gaussian process techniques.
The paper tackles the problem of debugging and fine-tuning controllers for autonomous robots in high-dimensional systems by proposing a performance function defined on a feature-parameter space, enabling prediction of task success and insights into controller limits; it demonstrates this approach in simulation and physical robot experiments with sample-efficient propagation.
Understanding a controller's performance in different scenarios is crucial for robots that are going to be deployed in safety-critical tasks. If we do not have a model of the dynamics of the world, which is often the case in complex domains, we may need to approximate a performance function of the robot based on its interaction with the environment. Such a performance function gives us insights into the behaviour of the robot, allowing us to fine-tune the controller with manual interventions. In high-dimensionality systems, where the actionstate space is large, fine-tuning a controller is non-trivial. To overcome this problem, we propose a performance function whose domain is defined by external features and parameters of the controller. Attainment regions are defined over such a domain defined by feature-parameter pairs, and serve the purpose of enabling prediction of successful execution of the task. The use of the feature-parameter space -in contrast to the action-state space- allows us to adapt, explain and finetune the controller over a simpler (i.e., lower dimensional space). When the robot successfully executes the task, we use the attainment regions to gain insights into the limits of the controller, and its robustness. When the robot fails to execute the task, we use the regions to debug the controller and find adaptive and counterfactual changes to the solutions. Another advantage of this approach is that we can generalise through the use of Gaussian processes regression of the performance function in the high-dimensional space. To test our approach, we demonstrate learning an approximation to the performance function in simulation, with a mobile robot traversing different terrain conditions. Then, with a sample-efficient method, we propagate the attainment regions to a physical robot in a similar environment.