Positioning device and method for detecting a laser beam
AssigneeTrimble Navigation Limited
InventorsLars Schumacher, Robert G. Conner
Life of this patent
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Abstract
The present disclosure relates to a positioning system including a positioning device and method for detecting light of fan shaped laser beam. The positioning device includes a detector for detecting light of the fan shaped laser beam rotating around a propagation axis with a direction of rotation and having two detector elements arranged in a known spatial relation for outputting a detection signal when irradiated. A position determining unit is used to obtain a first set of detection signals from the detector elements, to determine a first time relation between the detection signals of the first set, and to determine a positional relation between the detector and the propagation axis based on the first time relation.
Claims17
A positioning device, comprising:
- a detector for detecting light of a fan shaped laser beam rotating around a propagation axis with a direction of rotation and having at least two detector elements (A, B) arranged in a known spatial relation to one another for outputting a detection signal when irradiated by the fan shaped laser beam;
- and
- a position determining unit adapted to
- obtain a first set of detection signals from the detector elements wherein the first set of detection signals is obtained from detector elements arranged along a first line,
- determine at least one first time relation between the detection signals of the first set,
- determine a positional relation between the detector and the propagation axis based on the first time relation,
- obtain a second set of detection signals from detector elements arranged along a second line, the first and second lines not being parallel with respect to one another,
- determine at least one second time relation between the detection signals of the second set,
- determine a repetition time interval between two detection signals from the same detector element and to determine an angular velocity (ω) of the fan shaped laser beam based thereon,
- determine a first time interval between the detection signals of the first set and a second time interval between the detection signals of the second set,
- determine, based on the angular velocity of the fan shaped laser beam and the first and second time intervals of a plurality of detector elements, two angles between the detector elements, and
- determine, based on the two detector element angles and the spatial relation of the detector elements, a distance of the detector to the propagation axis.
A positioning method, comprising:
- detecting light of a fan shaped laser beam rotating around a propagation axis with a direction of rotation by a detector with at least two detector elements (A, B) arranged in a known spatial relation to one another and outputting a detection signal when irradiated by the fan shaped laser beam;
- obtaining a first set of detection signals from the detector elements;
- determining at least one first time relation between the detection signals of the first set;
- determining a positional relation between the detector and the propagation axis based on the first time relation;
- obtaining the first set of detection signals from detector elements arranged along a first line;
- obtaining a second set of detection signals from detector elements arranged along a second line, the first and second lines not being parallel with respect to one another;
- determining at least one second time relation between the detection signals of the second determining a repetition time interval between two detection signals from the same detector element;
- determining an angular velocity (ω) of the fan shaped laser beam based thereon;
- determining a first time interval between the detection signals of the first set and a second time interval between the detection signals of the second set;
- determining, based on the angular velocity of the fan shaped laser beam and the first and second time intervals of a plurality of detector elements, two angles between the detector elements;
- and
- determining, based on the two detector element angles and the spatial relation of the detector elements, a distance of the detector to the propagation axis.
Dependencies are inferred from the claim text.