SBIR-STTR Award

Non-Contacting Torque Sensor for Helicopter Tail Rotor Drive Systems. Abstract: Torque pervades our everyday life, and without even thinking about it, we rotate or use products that rotate hundreds of times a day. The challenge in the present application is to be able to measure transient torque accurately, economically, and in a non-contact manner in a demanding environment. International Electronic Machines Corporation, which is an instrumentation and sensor development company with products in over 15 countries, proposes to perform a feasibility comparison of two innovative approaches which can meet the challenges of the present application and do not suffer from the shortcomings of present approaches. Based on IEM's preliminary calculations, these approaches will be able to provide all of the required performance specifications. In Phase I of this project, IEM will evaluate the two approaches and further develop one of the two approaches. IEM will build a pre-prototype of the selected approach to demonstrate its performance. The output from the torque sensor will be integrated into a fatigue monitoring approach. The potential applications include: transportation market, process control, machine monitoring

There is an increasing need for an accurate (within 2%) method for measuring the torque of a helicopter tail rotor shaft. Current methods are expensive and suffer from a number of other flaws including complicated manufacturing/installation issues, limited accuracy (5%), and so on. International Electronic Machines (IEM) Corp., a leader in the field of sensor instrumentation technology for transportation applications, proposes to develop a non-contacting torque sensor for helicopter tail rotor drive systems. This system will build upon the results obtained in the Phase I work on this same topic; in this Phase I work IEM determined that the preferred approach will involve magnetic encoder technology. The final product of the Phase II research will be a system which is: accurate to 1% of full-scale torque (making considerable extra power available for maneuvering), inexpensive, easy to install/maintain, reliable, able to log rotor data for analysis or use in fatigue models, fast for tracking transient loads, and adaptable to various shaft locations. Boeing, the manufacturer of the Chinook rotorcraft which is the specific subject of this research, was favorably impressed by IEM's preliminary work and has offered assistance for the Phase II effort and potential financial support for later commercial development.

Keywords:
TORQUE MEASUREMENT, NONCONTACT, MAGNETIC ENCODER, SIGNAL PROCESSING, ROTORCRAFT, DRIVE SYSTEMS