Patent attributes
A vibration type gyroscope uses a resonator formed of a MEMS. At the time of startup, a lock state determination unit stabilizes an amplitude of a drive signal and outputs a lock signal when the amplitude is stabilized. A phase shifter generates an orthogonal signal by shifting, by 90°, the phase of the drive signal, and a phase compensator outputs a phase signal having a phase corresponding to a control signal based on the orthogonal signal and the in-phase signal of the drive signal. A multiplier multiplies a sense signal and the phase signal outputted from the phase compensator, and a control LPF performs filtering on a multiplication result. A control unit inputs a zero level signal to a PI controller during an initial state, and starts phase control by receiving an output signal of the control LPF, and ends the control when the signal is stabilized around the zero level.
