WO2023101395A1

WO2023101395A1 - Apparatus for evaluating performance of three-dimensional distance measurement camera

Info

Publication number: WO2023101395A1
Application number: PCT/KR2022/019168
Authority: WO
Inventors: 손현성
Original assignee: (주)미래컴퍼니
Priority date: 2021-11-30
Filing date: 2022-11-30
Publication date: 2023-06-08
Also published as: KR20230080926A; KR102591863B1

Abstract

One embodiment of the present invention provides an apparatus for evaluating the performance of a three-dimensional distance measurement camera, the apparatus comprising: a three-dimensional distance measurement camera including a light-emitting unit and a light-receiving unit; an object unit including two or more objects arranged to be spaced apart from each other at different distances from the three-dimensional distance measurement camera; a phase adjustment unit for adjusting the phase of an output light pulse output by the light-emitting unit; and a control unit which determines an adjustment width of the phase of the output light pulse using a measurable range of the three-dimensional distance measurement camera and a maximum distance from the three-dimensional distance measurement camera to the object unit, controls the phase adjustment unit to adjust the phase of the output light pulse according to the adjustment width, calculates a measurement distance using a time difference between an output time of the output light pulse and a reception time of a reflected light pulse reflected from the object unit, and compares the measurement distance with an actual distance of the objects to evaluate the performance of the three-dimensional distance measurement camera.

Description

3D distance measurement camera performance evaluation device

An embodiment of the present invention relates to a performance evaluation device for a 3D distance measuring camera.

A 3D distance measuring camera is a camera that irradiates light to an object and detects the reflected light signal to calculate the distance. It irradiates light to an object and calculates the reflected light through a formula using a sine wave phase to convert it into distance information. do.

In such a 3D distance measurement camera, a measurement distance is determined according to a modulation frequency, and it is necessary to evaluate distance accuracy for the entire range of the measurement distance.

Conventionally, in order to evaluate the performance of such a 3D distance measurement camera, a method of installing a stage capable of moving as much as the entire measurement distance or measuring only a specific section was used. However, this method has a problem in that a wider space must be secured as the measurement distance of the 3D distance measurement camera increases, and cost increases and inspection time increases due to an increase in equipment to be installed in the space.

An embodiment of the present invention determines the pulse phase degree using the measurement range of the 3D distance measuring camera and the actual distance to the object, and moves the pulse phase, thereby minimizing space constraints and evaluating accurate performance. It is intended to provide a performance evaluation device for a measurement camera.

An embodiment of the present invention, a 3D distance measuring camera including a light emitting unit and a light receiving unit, an object unit including two or more objects spaced apart from each other and disposed at different distances from the 3D distance measuring camera, by the light emitting unit The phase control unit for adjusting the phase of the output light pulse and the measurable range of the 3D distance measuring camera and the maximum distance from the 3D distance measuring camera to the object unit are used to determine the phase of the output light pulse. The control width is determined, the phase control unit is controlled to adjust the phase of the output light pulse according to the control width, and the time difference between the output time of the output light pulse and the reception time of the reflected light pulse reflected from the object unit is determined. A performance evaluation device for a 3D distance measuring camera including a control unit that calculates a measured distance using the distance and evaluates the performance of the 3D distance measuring camera by comparing the measured distance with the actual distance of the object.

The performance evaluation apparatus of the 3D distance measuring camera according to the embodiments of the present invention can evaluate the performance of the 3D distance measuring camera for the entire measurable range using an object unit fixed at a certain distance.

Through this, the performance evaluation device of the 3D distance measuring camera according to the embodiments of the present invention can implement a compact evaluation device and effectively reduce the performance evaluation time.

1 is a diagram schematically illustrating a performance evaluation apparatus of a 3D distance measuring camera according to an embodiment of the present invention.

2 is an exemplary view of a method of delaying a phase in a performance evaluation device of a 3D distance measurement camera according to an embodiment of the present invention.

3 is a diagram for explaining a method of delaying a phase of an output light pulse according to an embodiment of the present invention.

4 is a flowchart sequentially illustrating a performance evaluation method of a 3D ranging camera according to an embodiment of the present invention.

In one embodiment of the present invention, the object unit includes a first object having a first surface separated by a first distance from the 3D ranging camera and a second distance different from the first distance from the 3D ranging camera. It may include a second object having a second surface separated by a distance.

In one embodiment of the present invention, the first distance is a maximum distance from the 3D ranging camera to the object unit, and the second distance may be shorter than the first distance.

In one embodiment of the present invention, the control unit divides the cycle of the output light pulse into equidistant intervals to determine the adjustment width, and determines the measurable range of the 3D distance measurement camera as the 3D distance. The adjustment width may be determined by dividing the period of the output light pulse by the number divided by the maximum distance from the measuring camera to the object unit.

In one embodiment of the present invention, the control unit evaluates the performance of the 3D distance measuring camera by sequentially delaying the phase of the output light pulse according to the adjustment width, and the control unit determines the phase of the output light pulse. During sequential delay, the positions of the 3D ranging camera and the object unit may be fixed.

Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims and detailed description of the invention.

Hereinafter, the following embodiments will be described in detail with reference to the accompanying drawings, and when describing with reference to the drawings, the same or corresponding components are given the same reference numerals, and redundant description thereof will be omitted.

Since the present embodiments can apply various transformations, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. Effects and characteristics of the present embodiments, and methods for achieving them will become clear with reference to the details described later in conjunction with the drawings. However, the present embodiments are not limited to the embodiments disclosed below and may be implemented in various forms.

In the following embodiments, terms such as first and second are used for the purpose of distinguishing one component from another component without limiting meaning.

In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise.

In the following embodiments, terms such as include or have mean that features or elements described in the specification exist, and do not preclude the possibility that one or more other features or elements may be added.

In the following embodiments, when a part such as a unit, area, component, etc. is on or above another part, not only when it is directly above the other part, but also when another unit, area, component, etc. is interposed therebetween Including case

In the following embodiments, terms such as connect or combine do not necessarily mean direct and/or fixed connection or coupling of two members unless the context clearly indicates otherwise, and does not mean that another member is interposed between the two members. not to exclude

It means that the features or components described in the specification exist, and the possibility that one or more other features or components may be added is not excluded in advance.

In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the following embodiments are not necessarily limited to those shown.

1 is a diagram schematically illustrating a performance evaluation apparatus 10 of a 3D distance measurement camera according to an embodiment of the present invention.

Referring to FIG. 1 , an apparatus for evaluating the performance of a 3D distance measurement camera 10 according to an embodiment of the present invention includes a 3D distance measurement camera 100, an object unit 200, a phase control unit 300, and a control unit. (400).

The 3D distance measurement camera 100 may include a light emitter 110 that emits output light and a light receiver 120 that receives reflected light reflected from a subject. The light emitting unit 110 and the light receiving unit 120 of the 3D distance measuring camera 100 are synchronized with each other, so that when the output light of the light emitting unit 110 is generated, the light receiving unit 120 may also operate in the exposure (On) mode. there is.

The 3D distance measuring camera 100 synchronizes the two pulse signals, so that output light generated from the light emitting unit 110 is reflected from the subject and incident to the light receiving unit 120, and through this, an image of the subject may be obtained.

The maximum measurement distance of the 3D distance measurement camera 100, that is, the measurement range is determined according to the modulation frequency used for light output, and the time of one cycle of the modulation frequency can be matched with the actual distance. The measurement range of the 3D distance measurement camera 100 may be calculated through Equation 1 below.

Here, C is the speed of light (3*10 ¹¹ mm), and f means the modulation frequency of the 3D distance measuring camera 100. For example, when the modulation frequency f of the 3D distance measurement camera 100 whose performance is to be evaluated is 50 MHz, the measurement range may be 3000 mm.

The object unit 200 may include two or

more objects

210 , 220 , 230 , 240 , and 250 disposed at different distances from the 3D distance measuring camera 100 . Specifically, the object unit 200 includes a first object 210 having a first surface A1 separated from the 3D distance measuring camera 100 by a first distance d1, and the 3D distance measuring camera 100. ) may include a second object 220 having a second surface A2 separated from the first distance d1 by a second distance d2 different from the first distance d1.

In this case, the first distance d1 of the first object 210 may be the maximum distance of the object unit 200 from the 3D distance measuring camera 100, and the second distance d2 of the second object 220 may be shorter than the first distance d1. If the object unit 200 includes

more objects

230, 240, and 250, each of the

objects

210, 220, 230, 240, and 250 may have measurement surfaces having different distances from each other. .

As an embodiment, as shown in FIG. 1 , when the first to

fifth objects

210, 220, 230, 240, and 250 are included, each of the objects may have measuring surfaces spaced apart at equal intervals. there is.

For example, the first distance d1 from the 3D distance measuring camera 100 to the first surface A1 of the first object 210 is 1000 mm, and the second surface of the second object 220 ( The second distance d2 to A2) may be 800 mm. Similarly, the distances from the third object 230 to the fifth object 250 may be 600 mm, 400 mm, and 200 mm, spaced apart at intervals of 200 mm.

The 3D distance measurement performance evaluation apparatus 10 according to an embodiment of the present invention includes the object unit 200, so that measurement accuracy for each distance can be measured at once without moving the subject.

The plurality of

objects

210 , 220 , 230 , 240 , and 250 may be arranged in a direction perpendicular to the irradiation direction of the output light of the 3D distance measuring camera 100 to form one object unit 200 . However, in this case, the width of the object unit 200 composed of the plurality of

objects

210, 220, 230, 240, and 250 is determined by the measurement angle θ of the 3D distance measurement camera 100. can be placed within the range.

The phase control unit 300 may adjust the phase of the output light pulse output by the light emitting unit 110 . The phase control unit 300 may sequentially delay the phase of the output light pulse according to the control width determined by the controller 400 to be described later. A phase control method in the phase control unit 300 will be described later.

The controller 400 adjusts the phase of the output light pulse using the measurable range of the 3D distance measuring camera 100 and the maximum distance d1 from the 3D distance measuring camera 100 to the object unit 200. width can be determined. The controller 400 may control the phase control unit 300 to adjust the phase of the output light pulse according to the control width. In addition, the control unit 400 calculates the measurement distance using the time difference between the output time of the output light pulse and the reception time of the reflected light pulse reflected from the object unit 200, and compares the measured distance with the object to create a 3D distance measuring camera. (100) can be evaluated.

More specifically, a method for evaluating the performance of a 3D ranging camera will be described with reference to FIGS. 2 to 4 .

2 is an exemplary view of a method for delaying a phase in a performance evaluation device of a 3D distance measuring camera according to an embodiment of the present invention, and FIG. 3 is a delay phase of an output light pulse according to an embodiment of the present invention. FIG. 4 is a flowchart sequentially illustrating a method for evaluating the performance of a 3D distance measuring camera according to an embodiment of the present invention.

2 to 4, first, the control unit 400 displays the modulation frequency value of the 3D distance measuring camera 100 and the maximum distance d1 from the 3D distance measuring camera 100 to the object unit 200. can be stored.

The maximum distance d1 from the 3D distance measuring camera 100 to the object unit 200 may be a preset value as the position of the 3D distance measuring camera 100 and the object unit 200 are fixed. . Also, the modulation frequency of the 3D distance measuring camera 100 may vary depending on the camera to be measured. The controller 400 may store these values in advance.

Thereafter, the controller 400 substitutes the modulation frequency of the 3D distance measuring camera 100 into Equation 1 to determine the measurable range, and uses the determined measurable range and the maximum distance d1 to determine the phase of the output light. It is possible to determine the adjustment width of (S100).

Here, T is the period of the output light pulse and is matched to the maximum distance to the real object unit 200, and N is the measurable range of the 3D distance measuring camera 100 from the 3D distance measuring camera 100 to the object unit ( 200) may be an integer determined by dividing by the maximum distance d1.

For example, when the modulation frequency of the 3D distance measuring camera 100 is 50 MHz, the measurable range may be 3000 mm as described above. If the maximum distance d1 of the object unit 200 within the performance evaluation device 10 of the 3D distance measuring camera is 1000mm, N may be 3000mm/1000mm=3, and the phase of the output light pulse is adjusted. The width may be T/3.

The controller 400 may control the phase control unit 300 to adjust the phase of the output light pulse to be delayed by the control width (S110). More specifically, the control unit 400 may divide the period T of the output light pulse into equal intervals and adjust the delay by the determined adjustment width.

However, the controller 400 first evaluates the performance in a state in which the phase is not delayed, as shown in (a) of FIG. 2 . In this case, the performance evaluation apparatus 10 of the 3D distance measuring camera may evaluate the performance of the 3D distance measuring camera up to the maximum distance d1 of the object unit 200 .

Thereafter, the controller 400 may evaluate the performance of the 3D distance measurement camera 100 again by delaying the phase by the determined adjustment width, as shown in (b) of FIG. 2 . In this case, an effect of moving the measurement distance as much as the phase delay may occur.

In other words, when the control unit 400 moves the pulse phase by T/3, the 3D distance measuring camera 100 recognizes that it has moved by 1/3 of the measurable range, and thus the real object unit 200 Performance can be evaluated from the maximum distance (d1) to twice the maximum distance (d1*2). While the control unit 400 sequentially delays the phase of the output light pulse, the positions of the 3D distance measurement camera 100 and the object unit 200 are fixed.

Thereafter, the control unit 400 may determine whether the N-th phase lag occurs (S140), and if the N-th phase lag is exceeded, the output of the output light pulse may be stopped, and the performance of the 3D ranging camera 100 may be evaluated. there is. For example, as shown in (c) of FIG. 2 , the control unit 400 shifts the pulse phase by 2T/3, thereby increasing the distance from twice (d1*2) of the maximum distance of the real object unit 200 to 3 of the maximum distance. Performance can be evaluated between ships (d1*3).

For performance evaluation, the control unit 400 controls the light emitting unit 110 to output an output light pulse to the object unit 200 (S120), receives a reflected light pulse through the light receiving unit 120, and outputs the output light pulse. The performance of the 3D distance measuring camera 100 can be evaluated by calculating the measurement distance using the time difference between the output time and the reception time of the reflected light pulse.

Through the above method, the performance evaluation apparatus of the 3D distance measuring camera according to the embodiments of the present invention uses the object unit 200 fixed at a certain distance to provide a 3D distance measuring camera (100) for the entire measurable range. ) to evaluate the performance.

As such, the present invention has been described with reference to one embodiment shown in the drawings, but this is merely exemplary, and those skilled in the art will understand that various modifications and variations of the embodiment are possible therefrom. Therefore, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

The present invention relates to a performance evaluation device for a 3D distance measuring camera, and can be applied to all technical fields using a 3D distance measuring camera.

Claims

A 3D distance measuring camera including a light emitting unit and a light receiving unit;

an object unit including two or more objects spaced apart from each other at different distances from the 3D distance measuring camera;

a phase control unit for adjusting the phase of the output light pulse output by the light emitting unit; and

An adjustment width of the phase of the output light pulse is determined using a measurable range of the 3D distance measuring camera and a maximum distance from the 3D distance measuring camera to the object unit, and the output light is adjusted according to the adjustment width. The phase control unit is controlled to adjust the phase of the pulse, and a measurement distance is calculated using a time difference between an output time of the output light pulse and a reception time of the reflected light pulse reflected from the object unit, and the measurement distance and the object 3D distance measuring camera performance evaluation device comprising a;
According to claim 1,

The object unit includes a first object having a first surface spaced apart from the 3D distance measuring camera by a first distance and a second surface spaced apart from the 3D distance measuring camera by a second distance different from the first distance. An apparatus for evaluating the performance of a 3D distance measuring camera including a second object.
According to claim 2,

The first distance is the maximum distance from the 3D ranging camera to the object unit,

The second distance is shorter than the first distance, the performance evaluation device of the 3D ranging camera.
According to claim 1,

The control unit determines the control width by dividing the period of the output light pulse into equidistant intervals, and sets the measurable range of the 3D distance measuring camera to the maximum from the 3D distance measuring camera to the object unit. The apparatus for evaluating the performance of a 3D distance measuring camera, wherein the adjustment width is determined by dividing the cycle of the output light pulse by the number divided by the distance.
According to claim 4,

The control unit evaluates the performance of the 3D distance measurement camera by sequentially delaying the phase of the output light pulse according to the control width,

While the control unit sequentially delays the phase of the output light pulse, positions of the 3D ranging camera and the object unit are fixed.