DIMENSIONING SYSTEM

• US 20140049616A1
• Filed: 10/28/2013
• Published: 02/20/2014
• Est. Priority Date: 05/10/2005
• Status: Active Grant

• Current Assignee: Continental Autonomous Mobility US LLC (Continental AG)
• Original Assignee: Roger Stettner
• Inventors: STETTNER, Roger
• Granted Patent: US 8,878,978 B2
• Time in Patent Office: Days
• US Class Current: 348/47
• CPC Class Codes: B07C 3/14 using light-responsive detecting means for information carriers G06K7/14
• CPC Class Codes: B07C 5/362 Separating or distributor mechanisms switches for postal sorting B07C3/065; particular discharging devices for B65G47/74
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques
• CPC Class Codes: G01B 11/04 specially adapted for measuring length or width of objects while moving
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01B 11/285 using photoelectric detection means
• CPC Class Codes: G01S 17/14 wherein a voltage or current pulse is initiated and terminated in accordance with the pulse transmission and echo reception respectively, e.g. using counters
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: H04N 13/204 using stereoscopic image cameras stereoscopic photography G03B35/00
• CPC Class Codes: Y10S 901/47 Optical

Abstract

The present invention determines the dimensions and volume of an object by using a novel 3-D camera that measures the distance to every reflective point in its field of view with a single pulse of light. The distance is computed by the time of flight of the pulse to each camera pixel. The accuracy of the measurement is augmented by capture of the laser pulse shape in each camera pixel. The camera can be used on an assembly line to develop quality control data for manufactured objects or on a moving or stationary system that weighs as well as dimensions the objects. The device can also ascertain the minimum size of a box required to enclose an object.

Claims

1. A robotic vision and movement system comprising:

a robotic vision device with a field of view, adapted to measure the dimensions and relative position of an abject within said field of view, and having a 3D image output, and a 2D image output;

a computer connected to the 3D image output, and to the 2D image output, the computer adapted to determine a desired relative movement and having a command output;

a movement system, connected to the command output, adapted to create a relative motion between the robotic vision device and the object upon command from the computer;

said robotic vision device including;

a 2D imaging camera having a 2D image output; and

a 3D flash ladar, further including;

a pulsed light source;

a beam shaping element adapted to distribute light from said pulsed light source over said field of view;

a readout integrated circuit;

an optical sampler adapted to sample the output of said pulsed light source, and having an electrical time zero electrical output connected to the readout integrated circuit, and producing a time zero electrical signal;

a lens system for collecting pulsed light reflected from said object;

a focal plane array positioned at a focal plane of said lens system, and having a regular geometric arrangement of light sensitive detectors, each detector producing an electrical pulse response signal from an incident pulsed light signal, and each of said light sensitive detectors electrically connected to an input of a unit cell electrical circuit of the readout integrated circuit, wherein the readout integrated circuit provides the time zero reference electrical signal and a clock signal to each of the unit cell electrical circuits; and

wherein each unit cell electrical circuit includes;

an input amplifier with an amplifier output connected to the inputs of a plurality of switches, and each switch having an output connected to one of a plurality of memory capacitors;

a logic element with a plurality of sequenced outputs, each of said sequenced outputs connected to the control input of one of said switches, each sequenced output of said logic element adapted to turn one of said switches on and off in a predetermined sequence upon a transition of said clock, thus producing a voltage on each of the memory capacitors, the voltage comprising an analog sample of said electrical pulse response signal;

a unit cell counter connected to the logic element, the unit cell counter adapted to count the number of analog samples taken following the time zero electrical signal;

a trigger circuit with an output connected to said logic element, the trigger circuit adapted to terminate the analog sampling and the counting; and

a unit cell multiplexer having a plurality of inputs, wherein each of said inputs is connected to one of said plurality of memory capacitors;

wherein each of the unit cell multiplexers and unit cell counters includes an output connected to a global multiplexer of the readout integrated circuit, the global multiplexer having a respective digital output for each of the unit cell counter outputs as well as an analog output connected to an analog to digital converter adapted to convert the unit cell analog samples into digitized analog samples;

wherein the 3D image output corresponds to the counted number of analog samples and the digitized analog samples taken by each unit cell.

2. The robotic vision and movement system of claim 1, wherein said logic element comprises a delay circuit and a shift register

3. The robotic vision and movement system of claim 1, wherein said optical sampler is a photodiode.

4. The robotic vision and movement system of claim 1, wherein said optical sampler is adapted to capture a laser pulse shape reference.

5. The robotic vision and movement system of claim 1, wherein the clock is provided by a clock generator residing outside of the readout array on a circuit board.

6. The robotic vision and movement system of claim 1, wherein said analog samples capture the reflected laser pulse shape.

7. The robotic vision and movement system of claim 1, wherein said lens system further comprises a beamsplitter.

8. The robotic vision and movement system of claim 1, wherein said 2D imaging camera receives incident light through said lens system.

9. The robotic vision and movement system of claim 1, wherein said two dimensional imaging device receives incident light through a beamsplitter.

10. The robotic vision and movement system of claim 1, wherein a 2D image from said 2D imaging camera is overlaid on a 3D image from said 3D flash ladar.

11. A robotic vision and movement system comprising:

a robotic vision device with a field of view, adapted to measure the dimensions and relative position of an object within said field of view, and having a 3D image output, and a 2D image output;

a computer connected to both the 3D image output and the 2D image output, the computer adapted to determine a desired relative movement, and the computer having a command output connected to a movement system;

a movement system adapted to create a relative motion between the robotic vision device and the object upon command from the computer;

said robotic vision device further comprising;

a 2D imaging camera having a 2D image output; and

a 3D flash ladar including;

a pulsed light source;

a beam shaping element adapted to distribute light from said pulsed light source over said field of view;

a readout integrated circuit;

an optical sampler adapted to sample the output of said pulsed light source, and having an electrical time zero electrical output connected to the readout integrated circuit, and producing a time zero electrical signal;

a lens system for collecting pulsed light reflected from said object;

a focal plane array positioned at a focal plane of said lens system, and having a regular geometric arrangement of light sensitive detectors, each detector producing an electrical pulse response signal from an incident pulsed light signal, and each of said light sensitive detectors electrically connected to an input of a unit cell electrical circuit of a readout integrated circuit, wherein the readout integrated circuit provides the time zero reference electrical signal and a clock signal to each of the unit cell electrical circuits;

wherein each unit cell electrical circuit includes;

an input amplifier with an amplifier output connected to a plurality of analog samplers, each analog sampler connected to a memory capacitor;

a logic element with a plurality of sequenced outputs, each of said sequenced outputs connected to a control input of one of said analog samplers, each sequenced output of said logic element adapted to turn one of said analog samplers on and off in a predetermined sequence upon a transition of said clock thus producing a sequence of voltage samples of said electrical pulse response signal, wherein said analog samples are stored on the memory capacitors;

a unit cell counter connected to the logic element adapted to count the number of analog samples taken following the time zero electrical signal and to provide the number of analog samples as a unit cell digital counter output;

a trigger circuit with an output connected to said logic element, the trigger circuit adapted to terminate both the analog sampling and the counting;

a global multiplexer resident on the readout integrated circuit, the global multiplexer connected to each unit cell and including;

a global digital output adapted to output the unit cell digital counter outputs in sequence;

a global analog output adapted to output the unit cell analog samples in sequence, wherein the global analog output is connected to an analog to digital converter adapted to convert the unit cell analog samples into digitized analog samples; and

wherein the 3D image output corresponds to the unit cell counter outputs and the digitized analog samples taken by each unit cell.

12. The robotic vision and movement system of claim 11, wherein said logic element comprises a delay circuit and a shift register.

13. The robotic vision and movement system of claim 11, wherein said optical sampler is a photodiode.

14. The robotic vision and movement system of claim 11, wherein said optical sampler is adapted to capture a laser pulse shape reference.

15. The robotic vision and movement system of claim 11, wherein the clock is provided by a clock generator residing outside of the readout array on a circuit board.

16. The robotic vision and movement system of claim 11, wherein said analog samples capture the reflected laser pulse shape.

17. The robotic vision and movement system of claim 11, wherein said lens system further comprises a beamsplitter.

18. The robotic vision and movement system of claim 11, wherein said 2D imaging camera receives incident light through said lens system.

19. The robotic vision and movement system of claim 11, wherein said two dimensional imaging device receives incident light through a beamsplitter.

20. The robotic vision and movement system of claim 11, wherein a 2D image from said 2D imaging camera is overlaid on a 3D image from said 3D flash ladar.