Abstract
In the field of measuring system and robot system, optical sensors are often used on position measurement of objects. A development of high-speed position sensors is an important issue because the above systems require the position measurement at the time of the order of milli second or less along with high accuracy. CCD and PSD are currently used for position measurement of the systems. However, both sensors are difficult to shorten the position measurement time in principle.
This paper describes a new approach to scanning method of sensor array for high-speed position measurement of spot signal. The method of the position measurement is as follows. First, the method detects sensor element outputting maximum value of the sensor array by means of parallel processing technique. Second, the true peak position of spot signal is interpolated by a curve of secondary degree with these three sensor outputs. We constructed a prototype sensor system with mainly analog discrete circuits. Performance of the sensor system can be summarize as follows:
(1) linearity of 0.49%.
(2) short sampling frequency of 10kHz.
(3) little influence on background light.
The experiment results demonstrates that the proposed method is effective for high-speed position measurement.
