Integrated system for quickly and accurately imaging and modeling three-dimensional objects

• US 6,420,698 B1
• Filed: 10/23/1998
• Issued: 07/16/2002
• Est. Priority Date: 04/24/1997
• Status: Expired due to Term

• Current Assignee: Leica Geosystems AG (Hexagon AB)
• Original Assignee: Cyra Technologies, Inc. (Hexagon AB)
• Inventors: Dimsdale, Jerry
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US09/178,101
• Time in Patent Office: 1,362 Days
• Field of Search: 250/234, 250/235, 250/205, 250/559.06, 250/559.22, 250/216, 250/227.12, 250/559.1, 250/208.1, 356/4.02, 356/5.01, 356/4.09, 702/159, 702/167, 372/9, 372/10, 372/17, 372/24, 372/700
• US Class Current: 250/234
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/484 Transmitters

Abstract

An integrated system generates a model of a three-dimensional object. A scanning laser device scans the three-dimensional object and generates a point cloud. The points of the point cloud each indicate a location of a corresponding point on a surface of the object. A first model is generated, responsive to the point cloud, that generates a first model representing constituent geometric shapes of the object. A data file is generated, responsive to the first model, that can be inputted to a computer-aided design system.

Claims

1. A method of controlling the timing of output pulses from a laser for use in a device which requires scanning of the laser output, wherein each output pulse is generated in response to a pump pulse comprising the steps of:

monitoring the time delay between the initiation of the pump pulses and the subsequent generation of the associated output pulses;

predicting the time delay between the initiation of next pump pulse and the associated output pulse based on the monitored time delays and;

initiating the next pump pulse at a time selected to insure the output pulse is generated at a time to permit proper positioning of the laser output during the scan of the beam.

2. A method of operating a scanning laser system, said system including a laser which generates an output pulse in response to a pump pulse, with the time between the initiation of the pump pulse and the generation of the laser output pulse being variable, said scanning laser system further including a movable optical element for directing successive output laser pulses to different locations on a target to permit scanning of the target, said method comprising the steps of:

monitoring the position of the movable optical element;

monitoring the time delay between the initiation of the pump pulse and the subsequent generation of the associated output laser pulse; and

triggering the next pump pulse based on the monitored time delay and monitored position of the movable optical element to insure that the laser output is directed to the proper location on the target.

3. A method as recited in claim 2 wherein the time delay is determined by reading a counter which is started when the pump pulse is initiated and thereafter interrupted when the generation of the subsequent laser output pulse is detected.

4. A method as recited in claim 2 wherein the time delay between the initiation of the pump pulse and the subsequent generation of the associated output pulse is on the order of 100 to 300 microseconds.

5. A method as recited in claim 2 wherein the laser is a passively q-switched laser.

6. A method as recited in claim 5 wherein said laser is optically pumped with a diode laser.