Method and apparatus for determining the light transit time over a measurement path arranged between a measuring apparatus and a reflecting object
First Claim
1. A method for determining the light transit time along a measurement path arranged between a measuring apparatus and a reflecting object, wherein a light transmitter contained in the measuring apparatus sends a modulated light signal s(t) along the measurement path, which is received by a light receiver contained in the measuring apparatus, is converted into a received signal e(t) and is evaluated in the measuring apparatus, whereinthe light signal s(t) to be transmitted is stored in the form of digital values in a transmitter memory;
- wherein the stored digital values are sequentially read out and supplied to a digital/analog converter acted on by a clock signal and controlling the light transmitter;
wherein the received signal e(t) is supplied to an analog/digital converter acted on by the identical clock signal;
wherein the values delivered by the analog/digital converter are deposited in a receiver memory;
wherein a correlation function k(t) is formed between the signals s(t) and e(t) stored in the transmitter memory and in the receiver memory;
wherein a maximum Kmax =k(tmax) of the correlation function k(t) is found; and
wherein a polynomial p(t) is derived, the spacing of which from the correlation function k(t) in the region of Kmax is a minimum, and whose maximum Pmax =p(tmax/pol) is determined, with tmax/pol to the transit time to be determined.
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Accused Products
Abstract
The invention relates to a method for determining the light transit time along a measurement path arranged between a measuring apparatus and a reflecting object, wherein a light transmitter contained in the measuring apparatus sends a modulated light signal s(t) along the measurement path, which is received by a light receiver contained in the measuring apparatus, is converted into a received signal e(t), and is evaluated in the measuring apparatus, wherein the light signal s(t) to be transmitted is stored in the form of digital values in a transmitter memory; wherein the stored digital values are sequentially read out and supplied to a digital/analog converter acted on by a clock signal and controlling the light transmitter; wherein the received signal e(t) is supplied to an analog/digital converter acted on with the identical clock signal; wherein the values delivered by the analog/digital converter are deposited in a receiver memory; wherein a correlation function k(t) is formed between the signals s(t) and e(t) stored in the transmitter memory and in the receiver memory; and wherein the maximum Kmax =k(tmax) of the correlation function k(t) is found, with tmax corresponding to the transit time to be determined, and also to an apparatus for carrying out this method.
76 Citations
14 Claims
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1. A method for determining the light transit time along a measurement path arranged between a measuring apparatus and a reflecting object, wherein a light transmitter contained in the measuring apparatus sends a modulated light signal s(t) along the measurement path, which is received by a light receiver contained in the measuring apparatus, is converted into a received signal e(t) and is evaluated in the measuring apparatus, wherein
the light signal s(t) to be transmitted is stored in the form of digital values in a transmitter memory; - wherein the stored digital values are sequentially read out and supplied to a digital/analog converter acted on by a clock signal and controlling the light transmitter;
wherein the received signal e(t) is supplied to an analog/digital converter acted on by the identical clock signal;
wherein the values delivered by the analog/digital converter are deposited in a receiver memory;
wherein a correlation function k(t) is formed between the signals s(t) and e(t) stored in the transmitter memory and in the receiver memory;
wherein a maximum Kmax =k(tmax) of the correlation function k(t) is found; and
wherein a polynomial p(t) is derived, the spacing of which from the correlation function k(t) in the region of Kmax is a minimum, and whose maximum Pmax =p(tmax/pol) is determined, with tmax/pol to the transit time to be determined. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- wherein the stored digital values are sequentially read out and supplied to a digital/analog converter acted on by a clock signal and controlling the light transmitter;
Specification