Lightweight Arm Operations for Planetary Sample Return

The Beagle 2 robotic arm was studied to evaluate its suitability as a basis for the design of a lightweight instrument deployment arm for a future planetary rover mission. Newly developed circuitry allowed the arm to be driven in ways it had not been used previously. In particular, joint interpolated motion for straight-line trajectories was demonstrated. The repeatability of instrument positioning was found to be within 0.5 mm. Angular positioning of instruments was subject to larger errors (up to 4.5°), mainly due to known issues with bevel gears on the last two joints. This can easily be remedied without extensive re-design, making the arm highly suitable for a rover mission. In order to take full advantage of the capabilities of the arm, a calibrated physical deflection model will be required to replace the current kinematics model.