Three axis inertial measurement unit with counterbalanced, low inertia mechanical oscillator

摘要

An inertial measurement unit capable of providing information relating to all six degrees of freedom in an orthogonal three axis system is shown having a mechanical oscillator constructed from two counterbalanced platforms which form a single unit for low inertic rotation about a single torsional axis. Each platform has a Y-shaped rotor member whose legs are positioned between inwardly extending, mounting web members. Driving web members are provided on each side of the mounting web members for rotating the rotor member. A plurality of accelerometers are mounted upon at least one of the counterbalanced platforms. Each accelerometer has an input axis, an output axis, and pendulous axis. Each accelerometer is mounted such that the input axis is at a predetermined angle to the single axis of rotation and the counterbalanced platform. The accelerometers are used to measure angular rate along the pendulous axis and linear acceleration along the input axis. These signals may then be electronically separated to produce acceleration and angular rate outputs for a three axis orthogonal system.