| 摘要 |
PURPOSE:To eliminate fluctuation in sensitivity and the amount of offset of each piezoelectric element without adopting any additional circuit in a vibration type angular velocity detector. CONSTITUTION:When a vehicle is producing an angular velocity, both piezoelectric elements 30a and 30b for detection generate an angular velocity vibration voltage accompanied by vibration of both vibration pieces 20a and 20b. Ant amplifier 51 amplifies the angular velocity vibration voltage to an amplification vibration voltage. Only when the amplification vibration voltage is higher than a ground level, a comparator 52 generates a comparison voltage at a high level. Only when a phase-shift control voltage of a phase-shifting circuit 42 is higher than the ground level, a comparator 53 generates a comparison voltage at a high level. An exclusive OR circuit 54 calculates an exclusive OR of both comparison voltages and then generates a gate voltage. An LPF 60 generates low-frequency components of gate voltage from the exclusive OR circuit 54 as low-frequency components. An amplifier 70 amplifies a filter voltage of the LPF 60 to an angular velocity voltage and then outputs it. |
