Accelerometer based line-of-sight stabilization approach forpointing and tracking systems

摘要

Equipment operating from nonstationary platforms are subjected tonangular jitter resulting from vehicle linear and angular motions. Thenpurpose of a stabilized platform is to reject the angular disturbancesnso that the device modulation transfer function (MTF) is preserved atnthe system level. This paper describes a new platform stabilizationnapproach where miniature, low-cost, linear accelerometers are usedn(instead of gyroscopes) for line-of-Sight (LOS) stabilization. This isnaccomplished by placing the accelerometers at strategic locations, andncombining their outputs so that angular motion is determined from linearnacceleration measurements. The control system uses the sensed angularnaccelerations to generate movement commands for the gimbal servomotorsnin the stabilization platform. This counter-rotates the imaging devicento stabilize its LOS. The use of accelerometers allows the servo systemnto operate in an acceleration control mode which is more desirable thannposition or velocity control modes, typical of gyro-based systems, sincenthis increases stabilization bandwidth. Substituting gyros withnaccelerometers provides the additional benefits of lower sensor cost,nweight and power consumption, better temperature characteristics, morenrobustness, and higher shock resistance