SBIR Phase I: Compliant Force Control Module for Linear Actuators

Period of Performance: 07/01/2016 - 06/30/2017


Phase 1 SBIR

Recipient Firm

AndrosRobotics LLC
97 Hancock St. Unit 1
Cambridge, MA 02139
Firm POC, Principal Investigator


The broader impact/commercial potential of this project lies primarily in its contribution to the rehabilitation robotics, assistive technologies and collaborative robotics fields. Technologists engaged in developing devices and products in these fields are greatly benefiting from the lower prices of electronics brought on by the growth of the telecommunications industry, but those same technologists don?t have ready access to compliantly controlled actuators that make physical robot-human interaction safe. Developing such actuators is costly, it takes a long time, and it requires very specific and rare expertise. The introduction of a new line of inexpensive (as compared to existing technologies), highly backdrivable linear actuators onto the market will enable a new breed of robotic rehabilitation and assistive products, as well as co-robots and perhaps even gaming interfaces with haptic feedback. This Small Business Innovation Research (SBIR) Phase I project will focus on developing a proof of concept of the compliant force control module (CFCM), for converting simple linear screw-driven actuators into highly backdrivable, force-controlled actuators. There is great interest and opportunity in co-robots, but in order for these devices to safely manipulate objects and interact haptically with humans, they must be inherently safe. Compliant force-controlled actuators can render such co-robots safe, but due to their novelty such equipment is not commercially available. A proprietary force sensor design will be implemented and research will be performed on various methods for achieving high performance with sufficient stability margins in both hardware and software. Research will be performed on control algorithm approaches for minimizing the effects of mechanical play, stiction and inertia. The use of visco-elastic materials as the compliant element to replace the purely elastic elements (springs) will be investigated for the potential to mitigate the mechanical issues found in economical mechanical transmissions. The ultimate goal of the proposed effort is to demonstrate the improved force-control performance of an off-the-shelf linear actuator when equipped with the CFCM technology.