Miniature 70-W Brushless Motor-Controller for Compact Extraterrestrial-Based Actuation

Period of Performance: 06/10/2016 - 12/09/2016


Phase 1 SBIR

Recipient Firm

Barrett Technology, Inc.
NEWTON, MA 02458
Firm POC
Principal Investigator


This SBIR will support rover locomotion and manipulation with a system of newly-developed penny-sized 70-W brushless servomotor controllers that are networked on a bus-topology CANbus running CANopen. Each "P3" controller is small enough to be mounted in the tiny volume normally reserved for the encoder; and, indeed, each P3 carries the entire active electronics of the encoder function by measuring the magnetic field of a 6x2.5-mm radially-polarized button magnet bonded to the tail of the spinning motor shaft. A Kalman filter enables the encoder to read to 12-bits-absolute at commutated speeds up to 14,000 RPM. The controller has all of the functions expected of conventional controllers. However, based on three patents of international scope and a fourth PCT application, the part count has been substantially reduced, with subsequent reduced size, fewer parts to fail, fewer parts that otherwise generate quiescent power, and reduced cost. The Phase-I objectives will select two brushless servomotors of varying specifications that support NASA's rover missions. The electromechanical interface between P3 and the motors will be designed, assembled, fixtured with particle-brake loads, and then rigorously stress tested before working with NASA engineers to create a conceptual design for Phase II and beyond. Phase I is expected to result in a TRL of 4. Phase-II efforts will focus on design-modifications to address issues found in Phase-I and will encompass rigorous stress-testing in relevant environments. Phase II is expected to result in a TRL of 5. Phase-III commercialization efforts will create a system of motor controllers that not only support NASA rover missions, but also support other space-based non-terrestrial applications, such as servomotor actuation on satellites for precision antennae and laser pointing and the deployment of articulated structures.