Feasibility Checking and Constraint Refinement for Shared Control in Assistive Robotics

Shared control enables users with motor impairments to control high-dimensional assistive robots with low-dimensional user interfaces. The challenge is to simultaneously 1) provide support for completing daily living tasks 2) enable sufficient freedom of movement to foster user empowerment 3) ensure that shared-control support precludes the robot from running into kinematic limitations such as obstacles, unreachable areas, or loss of manipulability due to joint limits. In this letter, we propose a framework that performs feasibility checks before executing a shared-control task. We activate shared control only if a task is deemed feasible, and refine the task regions by excluding paths that are infeasible, e.g. due to obstacles or kinematic limitations. This reduces task failures, whilst still ensuring freedom of movement. We evaluate our framework on a set of daily living tasks with our wheelchair-based mobile manipulator EDAN.