Proximeter: An Automated Rover Arm Placement Safety Evaluation Tool

We present Proximeter, a software tool for efficient, repeatable evaluation of worst-case minimum clearance between triangular meshes representing robotic hardware and local terrain across a space of possible placements encoding placement uncertainty. These spaces can be adjusted to represent different uncertainty models and to account for terrain-aware placements such as those employing contact switches and various forms of rangefinding. Proximeter is an essential enabling component of safety evaluations for sampling activities on the Mars 2020 and Mars Science Laboratory (MSL) missions, allowing operators to rapidly validate tool placements against mission requirements and develop rover sequencing within the constraints of tactical operational planning. Proximeter can additionally be easily adapted to any number of mission architectures provided with appropriate hardware and kinematics models. We present the design of Proximeter, including the operational constraints that motivated the development of Proximeter and a novel application of Lipschitz optimization (LIPO) that greatly speeds up the evaluation of Proximeter queries. We then describe the various implementations of Proximeter for graphical, server-client, or command line interface, as well as the usage of Proximeter on both the MSL and Mars 2020 missions. Lastly, we discuss efforts to use Proximeter on the surface of Mars to enable autonomous placement of rover instruments without the need to wait for human evaluation and commanding.