HIGH ACCELERATION, HIGH-PERFORMANCE SOLID-STATE ACCELEROMETER DEVELOPMENT

This paper presents current accomplishments in the development of a high performance, high g, tactical accelerometer for use in the Advanced Kinetic Energy Missile (AdKEM) development program being conducted by the US Army Missile Command. The design goals of the accelerometer are to provide strapdown tactical navigation quality acceleration information throughout a 20 g soft launch phase, 1200 g boost phase, and low-g coast phase environment. The accelerometers must be able to provide acceleration measurements accurate enough to provide a navigational accuracy of 0.5 meter CEP at 500 meters. This translates to an accelerometer capable of measuring a 1200 g acceleration with a resolution of 1 milli-g. The AdKEM missile accelerometer and gyro outputs are used for control stability and midcourse guidance. The successful demonstration of this device offers a myriad of opportunities in both the commercial and military arenas. The operational environment and performance characteristics of the AdKEM accelerometer will be presented. This accelerometer is unique in the fact that it must not only survive but successfully operate through the 1200 g acceleration environment, while providing sufficient sensitivity to resolve applied accelerations down to a 1 milli-g level. This large 1.2 x 10(6) dynamic range is new for tactical missiles, where dynamic ranges of 10(4) are typical. Strategic missiles and position location applications have required similarly high dynamic ranges; however, this application is unique in acceleration range of milli-g's to g's. Other design requirements imposed on this accelerometer for viability in a tactical application are: minimum cost, size, weight and power consumption and survivability over a wide range operating environment. Crystalline quartz vibrating beam technology has been chosen for this accelerometer application to take advantage of solid state device characteristics. A solid state device with inherently digital output characteristics is desirable for strapdown navigation applications because of interface circuitry simplification, potential lower cost, inherent stability and longer storage life.