Dimensioning system
A dimensioning system that determines the dimensions and volume of an object by using a three-dimensional 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.
1. A dimensioning system, comprising:
an electronic camera adapted to measure dimensions and a position of an object, the electronic camera including a three dimensional image output, a two dimensional imaging device having a two dimensional image output, a pulsed laser light source, a beam shaping element adapted to distribute light from said pulsed laser light source, a readout integrated circuit, a laser pulse sampler adapted to sample the output of said pulsed laser light source and produce a time zero reference connected to the readout integrated circuit, a lens system for collecting pulsed laser light reflected from said object, a focal plane array positioned at a focal plane of said lens system having a geometric arrangement of light sensitive detectors, each detector producing an electrical pulse response signal from an incident pulsed laser 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 with the readout integrated circuit provides the time zero reference and a clock to each of the unit cell electrical circuits;
a computer including a motion command output, the computer being connected to the three dimensional image output and to the two dimensional image output to determine an intended motion;
wherein each unit cell electrical circuit includes:
an input amplifier including an amplifier output connected to the inputs of a plurality of switches with each of the switches having an output connected to one of a plurality of memory capacitors;
a logic element including a plurality of sequenced outputs that are connected to the control input of one of said switches and adapted to turn the one of said switches on and off in a predetermined sequence upon a transition of said clock producing a voltage comprising an analog sample of said electrical pulse response signal on each of the memory capacitors;
a unit cell counter connected to the logic element that is adapted to count the number of analog samples taken following the time zero reference;
a trigger circuit with an output connected to said logic element, the trigger circuit adapted to stop the analog sampling and the counting;
a counter output connected to an input of a digital multiplexer resident on the readout integrated circuit; and
a unit cell analog multiplexer having a plurality of inputs, that are each connected to one of said plurality of memory capacitors and an output connected to a global analog multiplexer of the readout integrated circuit, the global analog multiplexer having an analog output connected to an analog to digital converter adapted to convert the unit cell analog samples into digitized analog samples and the readout integrated circuit including a digital multiplexer output providing a digital output for a plurality of the unit cell counter outputs; and
wherein the three dimensional image output corresponds to the unit cell counter outputs and the digitized analog samples taken by each unit cell electrical circuit.
2. The dimensioning system of claim 1 , wherein said logic element comprises a delay circuit and a shift register.
3. The dimensioning system of claim 1 , wherein said laser pulse sampler is a photodiode.
4. The dimensioning system of claim 1 , wherein said laser pulse sampler is adapted to capture a laser pulse shape reference.
5. The dimensioning system of claim 1 , wherein the clock is provided by a clock generator residing outside of the readout integrated circuit on a supporting circuit board.
6. The dimensioning system of claim 1 , wherein said analog samples capture the reflected laser pulse shape.
7. The dimensioning system of claim 1 , wherein said lens system further comprises a beamsplitter.
8. The dimensioning system of claim 1 , wherein said two dimensional imaging device receives incident light through said lens system.
9. The dimensioning system of claim 1 , wherein said two dimensional imaging device receives incident light through a beamsplitter.
10. The dimensioning system of claim 1 , wherein a two-dimensional image from said two dimensional imaging device is overlaid on said three-dimensional image.
11. The dimensioning system of claim 1 , further comprising a conveyance system connected to the motion command output and adapted to produce motion of the object upon a motion command from the computer.
12. A dimensioning system comprising:
an electronic camera adapted to measure dimensions and a position of an object, the electronic camera including a three-dimensional image output that includes a plurality of pixels that each have a measured distance, a two-dimensional imaging device that includes a two-dimensional image output, a pulsed laser light source, a beam shaping element adapted to distribute light from the pulsed laser light source, a readout integrated circuit, a laser pulse sampler adapted to sample the output of the pulsed laser light source and adapted to produce a time zero reference connected to a readout integrated circuit and to produce a data set comprising a laser pulse shape reference and a lens system for collecting pulsed laser light reflected from said object, a focal plane array positioned at a focal plane of the lens system, and having a regular geometric arrangement of light sensitive detectors, each of the detectors producing an electrical pulse response signal from an incident pulsed laser 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, the readout integrated circuit provides the time zero reference and a clock to each unit cell electrical circuit; and
a computer, which has a motion command output, connected to the three-dimensional image output and to the two-dimensional image output, the computer adapted to determine an intended motion;
wherein each unit cell electrical circuit includes:
an input amplifier with an amplifier output connected to the inputs of a plurality of switches, each of the switches having an output connected to one of a plurality of memory capacitors;
a logic element having a plurality of sequenced outputs, each of said sequenced outputs connected to the control input of one of said switches and adapted to turn one of said switches on and off in a predetermined sequence upon a transition of said clock to produce a voltage on each of the memory capacitors, the voltage comprising an analog sample of said electrical pulse response signal;
a unit cell counter having a counter output connected to an input of a digital multiplexer on the readout integrated circuit providing a digital output for a plurality of the unit cell counter outputs, the unit cell connected to the logic element that is adapted to count the number of analog samples taken following the time zero reference; and
a trigger circuit having an output connected to said logic element, the trigger circuit adapted to stop the analog sampling and the counting;
a unit cell analog multiplexer having a plurality of inputs connected to one of said plurality of memory capacitors and an output connected to a global analog multiplexer of the readout integrated circuit, the global analog multiplexer having an analog output connected to an analog to digital converter adapted to convert the unit cell analog samples into digitized analog samples,
wherein the readout integrated circuit has a digital multiplexer output providing a digital output for a plurality of the unit cell counter outputs and
wherein the three-dimensional image output corresponds to the counter output and the digitized analog samples taken by each unit cell electrical circuit and a digital processor adapted to compare the data set comprising the laser pulse shape reference with the digitized analog samples from the unit cell, to obtain a more accurate distance measurement for a given pixel of said three-dimensional image.
13. The dimensioning system of claim 12 , wherein said logic element comprises a delay circuit and a shift register.
14. The dimensioning system of claim 12 , wherein said optical sampler is a photodiode.
15. The dimensioning system of claim 12 , wherein said two dimensional imaging device is a CMOS focal plane array.
16. The dimensioning system of claim 12 , wherein the clock is provided by a clock generator residing outside of the readout integrated circuit on a supporting circuit assembly.
17. The dimensioning system of claim 12 , wherein said analog samples capture the reflected laser pulse shape.
18. The dimensioning of claim 12 , wherein said lens system further comprises a beamsplitter.
19. The dimensioning system of claim 12 , wherein said two-dimensional imaging camera receives incident light through said lens system.
20. The dimensioning system of claim 12 , wherein said two dimensional imaging device receives incident light through a beamsplitter.
21. The dimensioning system of claim 12 , wherein a two-dimensional image from said two dimensional imaging device is digitally overlaid on a three-dimensional image from said electronic camera.
22. The dimensioning system of claim 12 , further comprising a conveyance system connected to the motion command output and adapted to produce motion of the object upon a motion command from the computer.