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DETERMINATION OF THE POSITION OF A LASER--MARKED OBJECT
Barbarić Žarko
Expressions for signals coming from laser-marked object positioning errors have been derived and linear, square and Gaussian approximation of positioning error signals have been analysed. The signal of positioning error is shown to be the function of the distance between the spot centre and the quadrant photodiode centre as long as this distance is less than the spot radius. From the expressions for positioning error signals, the expressions for the positioning angular error with the quadrant photodiode have been derived. It is shoun that this error depends unsignificantly on the positioning angle while it predominantly depends on the SNR. The positioning error is in inverse ratio to the square root from the signal to noise ratio in the sum signal channel. The method for calculating the receiving optical strenght, its dynamics and the SNR is given as well.Expressions for signals coming from laser-marked object positioning errors have been derived and linear, square and Gaussian approximation of positioning error signals have been analysed. The signal of positioning error is shown to be the function of the distance between the spot centre and the quadrant photodiode centre as long as this distance is less than the spot radius. From the expressions for positioning error signals, the expressions for the positioning angular error with the quadrant photodiode have been derived. It is shoun that this error depends unsignificantly on the positioning angle while it predominantly depends on the SNR. The positioning error is in inverse ratio to the square root from the signal to noise ratio in the sum signal channel. The method for calculating the receiving optical strenght, its dynamics and the SNR is given as well.
Ključne reči: Optoelectronics, laser technique, object, positioning, measuring error. |