Compact inertial measurement unit

An inertial measurement unit mountable on a vehicle, comprising a housing accommodating three solid state sensor couples, each couple comprising a gyro member and an associated accelerometer. The housing is in the shape of a triangular pyramid, with a base fitted with true position and fixation arrangements for positioning and fixing the housing at a predetermined relation with respect to an axis of the vehicle. Each of the solid state sensor couples is fitted on a respective face of the housing.