Optoelectronic sensor and method of measuring the distance from an object
AssigneeSick AG
InventorsStefan Kienzler, Martin Köhl, Kai Waslowski, Ulrich Zwölfer, Christophe Thil
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Abstract
An optoelectronic sensor is provided for measuring the distance from an object in a monitored zone that has a light transmitter for transmitting light signals into the monitored zone; a light receiver having at least one avalanche photodiode operated in Geiger mode for receiving the light signals reflected or remitted by the object; an individual time of flight measurement unit for determining an individual time of flight of a light signal from the sensor to the object; and an evaluation unit that is configured to generate a common measured value for the distance from a plurality of individual times of flight.
Claims18
An optoelectronic sensor for measuring the distance from an object in a monitored zone, the optoelectronic sensor having
- a light transmitter for transmitting light signals into the monitored zone;
- a light receiver having at least one avalanche photodiode operated in Geiger mode for receiving the light signals reflected or remitted by the object;
- an individual time of flight measurement unit for determining an individual time of flight of a light signal from the sensor to the object;
- and
- an evaluation unit that is configured to determine a common measured value for the distance from a plurality of individual times of flight,
- wherein the evaluation unit is furthermore configured to determine a received point in time ts forming the basis of the common measured value in a predefinable time interval having a lower time boundary t0 and an upper time boundary t1 from a model of the number N(t) of the avalanche photodiodes still available at a respective point in time t, with an avalanche photodiode still being available as long as no avalanche has been triggered therein.
A method of measuring the distance from an object in a monitored zone, the method comprising the steps of:
- transmitting a light signal into the monitored zone;
- receiving again the light signal reflected or remitted by the object by at least one avalanche photodiode of a light receiver operated in Geiger mode;
- measuring individual times of flight of the light signal from the object;
- and
- determining a common measured value for the distance from a plurality of individual times of flight, using an evaluation unit corresponding to an event pool or a number N(t) of still available avalanche photodiodes,
- wherein a received point in time ts forming the basis of the common measured value is determined in a predefinable time interval having a lower time boundary t0 and an upper time boundary t1 from a model of the number N(t) of the avalanche photodiodes still available at a respective point in time t, with an avalanche photodiode still being available as long as no avalanche has been triggered therein.
An optoelectronic sensor for measuring the distance from an object in a monitored zone, the optoelectronic sensor having
- a light transmitter for transmitting light signals into the monitored zone;
- a light receiver having at least one avalanche photodiode operated in Geiger mode for receiving the light signals reflected or remitted by the object;
- an individual time of flight measurement unit for determining an individual time of flight of a light signal from the sensor to the object;
- and
- an evaluation unit that is configured to determine a common measured value for the distance from a plurality of individual times of flight, corresponding to an event pool or a number N(t) of still available avalanche photodiodes,
- wherein the evaluation unit is furthermore configured to determine a received point in time ts forming the basis of the common measured value in a predefinable time interval having a lower time boundary t0 and an upper time boundary t1 from a model of the number N(t) of the avalanche photodiodes still available at a respective point in time t, with an avalanche photodiode still being available as long as no avalanche has been triggered therein,
- and wherein the evaluation unit is configured to determine at least one of a time parameter or a signal strength parameter.
Dependencies are inferred from the claim text.