| 摘要 |
The interference radiation formed by an optical fibre rotation sensor - termed fibre gyro for short - is detected by a photodiode 12 and converted in an evaluation device consisting of a current/voltage converter 18, band pass filter 19, matching amplifier 21, ring mixer 20 and DC amplifier 23, to form a voltage signal dependent on the rate of rotation acting on the sensor. This voltage signal is smoothed by means of a low bass filter 24 and forms an output signal which indicates a rotary movement. To date, the generation of a low-drift output signal has required expensive temperature-stabilised and drift-stabilised circuit elements. In addition, the latter have had to be screened against parasitic frequencies. It is proposed for the purpose of avoiding such expensive circuit engineering to interrupt (switch 26) the input signal or interference signal and to measure the output signal of the evaluation device in open-line operation. Said signal is switched by means of a switch 27 on a low pass filter 28, integrated and subtrated in a downstream processing unit from the output signal A. The determination of the error signal F can be performed intermittently during operation and permits continuous correction of the output signal. There is no longer any need for an expensive drift stabilisation of the evaluation circuit for the laser gyro. <IMAGE>
|
