摘要 |
A light based distance, velocity and acceleration sensor which uses phase difference to determine the desired measurement. A laser signal is modulated by an oscillator signal and reflected off an object to a signal receiver. The reflected laser signal and the oscillator signal then pass through a dual path conditioning circuit, where the path lengths and circuit elements of the two paths are identical to cancel the effects of propagation delays in an output signal. The conditioned signals are passed through a phase comparator, to produce a signal indicative of the phase difference between the oscillator signal and the reflected laser signal. The phase difference is directly proportional to the distance between the sensor and the object.
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