Enabling Failure Recovery for On-The-Move Mobile Manipulation

TL;DR

This paper introduces a reactive control method for mobile manipulators that improves failure recovery during on-the-move tasks by dynamically adjusting base placement, balancing reliability and performance.

Contribution

It proposes a novel reactive base control approach that enables mobile manipulators to recover from manipulation failures without stopping, enhancing on-the-move task efficiency.

Findings

System maintains target range during failure recovery

Improves task completion speed compared to open-loop methods

Demonstrated effectiveness in real-world experiments

Abstract

We present a robot base placement and control method that enables a mobile manipulator to gracefully recover from manipulation failures while performing tasks on-the-move. A mobile manipulator in motion has a limited window to complete a task, unlike when stationary where it can make repeated attempts until successful. Existing approaches to manipulation on-the-move are typically based on open-loop execution of planned trajectories which does not allow the base controller to react to manipulation failures, slowing down or stopping as required. To overcome this limitation, we present a reactive base control method that repeatedly evaluates the best base placement given the robot's current state, the immediate manipulation task, as well as the next part of a multi-step task. The result is a system that retains the reliability of traditional mobile manipulation approaches where the base comes to a stop, but leverages the performance gains available by performing manipulation on-the-move. The controller keeps the base in range of the target for as long as required to recover from manipulation failures while making as much progress as possible toward the next objective. See https://benburgesslimerick.github.io/MotM-FailureRecovery for videos of experiments.