NASA Marshall Space Flight Center has developed innovative resolver signal-conditioning technologies that provide rotational position information over a full 360 degrees. Furthermore, an electrical circuit conditions the output so that the shaft angle position is represented by a linear analog signal. The features of NASA's new technologies offer several advantages over standard resolver signal-conditioning circuits. In addition, these circuits can be used in many commercial applications.

Benefits

Potential Commercial Uses

These technologies are useful in any application that uses a resolver:

The Technology

One of the most robust, reliable, and often used position sensors is a resolver. Resolvers use external excitation signals, arctangent integrated circuits, resolver-to-digital integrated circuits, and output signal conditioning to determine angular position. Commercially available arctangent integrated circuits can operate only between -90 degrees and +90 degrees. This limitation is a problem for applications that require measurement over a full 360 degrees. Researchers at NASA Marshall Space Flight Center have developed a technology that solves this problem by providing a linear output for 360-degree rotation. In addition, some resolver circuits offer 360-degree sensing using precision analog circuitry and trigonometric identities. However, these circuits and identities are noise-sensitive, require precision components as well as gain- and phase-matching, and tend to drift with changes in temperature. NASA Marshall researchers also have invented a circuit that avoids these limitations and is lower in cost than typical resolver signal conditioning circuits.

Patent Number

6,104,328

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