CN105487322A - A lens structure for dual-image capturing and a method for measuring speed using it - Google Patents

Abstract

The present invention belongs to the technical field of video recording systems, and in particular, relates to a dual-image imaging lens structure, including a camera, a lens, and two-sided planar reflective elements, wherein the lens is arranged at the interface of the camera, and the two-sided planar reflective elements are symmetrically arranged at the front end of the lens with the straight line where the central axis of the lens is located as the symmetry axis, and the angle of the planar reflective elements is adjustable. Compared with the prior art, the present invention changes the optical path entering the video recording instrument by adding a planar reflective element group with an adjustable angle at the front end of the camera lens, thereby increasing the video recording range on the basis of only one camera and occupying a small space. The method can obtain images of the front and rear sides of the vehicle being photographed, solving the defects of the original traffic video recording equipment.

Description

A lens structure for dual-image capturing and a method for measuring speed using it

technical field

The invention belongs to the technical field of video recording systems, and in particular relates to a lens structure for dual image capturing and a speed measurement method using the same.

Background technique

Video recording equipment has been widely used in video surveillance, image positioning, appearance inspection and other fields. In order to strengthen the ability to control the traffic and ensure the smooth operation of the traffic, the modern general way of recording the operating vehicles is to install the recording equipment on the traffic road to monitor the operation of the traffic or collect traffic evidence. However, there are obvious disadvantages in this existing recording method: a recording device can only capture images in a single area, and the imaging range is limited. For operating vehicles, only one side of the front or rear can be recorded. However, it is impossible to record the other side of the vehicle, so that it is impossible to obtain relatively complete information about the vehicle being photographed. To record images in multiple areas, it is often necessary to add more lenses and supporting cameras, which will increase the cost and equipment maintenance costs, and also require more installation space.

In addition, the current application method of ITS speed measurement is to use a lens with a set of cameras, but limited by the depth of field of the lens, the speed measurement range is small, resulting in limitations in use. If you want to increase the range of speed measurement and at the same time ensure that the clarity of the photos you take meets the requirements, you may need two or more sets of equipment.

In view of this, it is indeed necessary to provide a lens structure for dual image capturing and a method for measuring speed by using it, which changes the light path entering the recording device by adding a reflective element sheet group with an adjustable angle at the front of the camera lens. On the basis of only one camera, the shooting range is increased, and the space occupied is small. The method can obtain the images of the front and rear sides of the vehicle to be photographed, and solves the defects of the original traffic recording equipment.

Contents of the invention

The object of the present invention is to: address the deficiencies of the prior art, and provide a lens structure and method for dual-image imaging, by adding an adjustable-angle reflective element sheet group at the front end of the camera lens, thereby changing the angle of entry into the camera. The light path, on the basis of only one camera, increases the shooting range and occupies a small space. The method can obtain the images of the front and rear sides of the vehicle to be photographed, and solves the defects of the original traffic recording equipment.

In order to achieve the above object, the present invention adopts following technical scheme:

A lens structure for dual image capturing, comprising a camera, a lens and two plane reflective elements, the lens is arranged at the interface of the camera, and the two plane reflective elements are symmetrically arranged on the front end of the lens with the line where the central axis of the lens is located as the symmetrical axis, And the angle of the plane reflective element can be adjusted.

As an improvement of the lens structure of the present invention, the distance between the ends of the two plane reflective elements close to the lens is smaller than the distance between the ends of the two plane reflective elements far away from the lens .

As an improvement of the lens structure of the dual-image capturing of the present invention, the included angle between the two plane reflective elements is 2θ, 10°<θ<80°.

As an improvement of the lens structure of the present invention, the distance between the contact points of the two plane reflective elements and the lens is 1/6 to 2/3 of the length of the plane reflective elements.

As an improvement of the lens structure of the dual image capturing of the present invention, an image storage unit and an image output unit are arranged in the camera, the output end of the image storage unit is connected to the input end of the image output unit, and the image output unit The output end of the unit is connected to the input end of the display unit, the image storage unit is used for storing the front image and the rear image of the vehicle to be photographed, and the image output unit is used for outputting the front image and the rear image of the vehicle to be photographed to the display unit.

As a kind of improvement of the lens structure of the dual image capturing of the present invention, a timing unit, a calculation unit, a data entry unit and a data output unit are also arranged in the camera, the output end of the data entry unit and the output end of the timing unit Both are connected to the input end of the calculation unit, the output end of the calculation unit is connected to the input end of the data output unit, the timing unit is used to time the time for the vehicle to be photographed to pass through a certain area, and the data entry unit uses For inputting the angle of the planar reflective element, the calculation unit is used to calculate the length of a certain area according to the angle of the planar reflective element, and to calculate the speed of the vehicle to be photographed, and the data output unit is used to output the calculated speed to other devices.

When in use, the present invention is installed on the top of the road section to be photographed. When the vehicle to be photographed enters the first recording area, the optical path passes through the lens and enters the camera after being reflected by the plane reflective element, thereby obtaining the vehicle to be photographed. front image of

Similarly, when the subject vehicle travels to the second recording area, the rear image of the subject vehicle is captured by the above method.

By adjusting the θ angle, that is, adjusting the angle between two symmetrically installed plane reflective elements, the distance between the first recording area and the second recording area can be adjusted according to the actual situation to achieve the most reasonable speed measurement need.

Compared with the prior art, the present invention has at least the following advantages:

First, there is no need to increase the recording equipment, and the recording range can be increased on the basis of one camera, thereby increasing the utilization rate of resources and reducing the investment of funds and various resources.

Second, the present invention only needs to add a group of plane reflective elements to achieve the purpose of recording images of the front and rear of the vehicle on the basis of the original recording, and takes up little space and is convenient for installation and debugging.

Third, without adding related supporting equipment, the speed measurement range can be increased, and the distance of the speed measurement range can be flexibly adjusted according to needs.

In a word, the present invention changes the light path entering the recording device by adding an adjustable-angle plane reflective element group at the front end of the camera lens, increases the recording range on the basis of only one camera, and occupies less space. The method can obtain the images of the front and rear sides of the vehicle to be photographed, and solves the defects of the original traffic recording equipment.

The present invention also provides a method for measuring speed using a dual-image imaging lens structure, comprising the following steps:

S1, adjust the angle of the plane reflective element, input the angle into the camera, and the camera calculates the distance D between the first recording area and the second recording area;

S2, when the front of the vehicle to be photographed enters the first recording area, start timing until the back of the vehicle to be photographed is about to leave the second recording area, the timing ends, and the timing is T seconds;

S3, calculate the vehicle speed, the vehicle speed V=D/T.

As an improvement of the method for measuring speed using a dual-image imaging lens structure in the present invention, the calculation formulas for the length L of the first recording area and the second recording area are:

L=h×tan2θ-h×tan(2θ-FOV/2);

The calculation formula of the distance d1 between the edges of the first shooting area and the second shooting area which are close to each other is: d1=2h×tan(2θ-FOV/2);

The calculation formula of the distance d2 between the edges of the first shooting area and the second shooting area which are far away from each other is: d2=2h×tan2θ;

Wherein, θ is the angle between the plane reflective element and the straight line where the central axis of the lens is located, h is the height of the end of the plane reflective element close to the lens from the ground, and FOV is the camera field of view angle.

Compared with the prior art, the present invention is simple and easy, and can quickly calculate the speed of the vehicle to be photographed, thereby solving the problem of the original speed measurement system with a small speed measurement range due to the limitation of the depth of field of the lens.

Description of drawings

Fig. 1 is a structural schematic diagram and an optical path diagram of the present invention (Embodiment 1).

Fig. 2 is a structural block diagram of the camera in the present invention (embodiment 1).

Fig. 3 is a block flow diagram of the speed measurement method of the present invention (embodiment 2).

detailed description

Example 1

As shown in Fig. 1 and Fig. 2, the lens structure of a kind of dual image capturing provided by the present invention comprises camera 1, lens 2 and two-sided plane reflective element 3, lens 2 is arranged at the interface of camera 1, and two-sided plane reflective element 3 is symmetrically arranged on the front end of the lens 2 with the straight line where the central axis of the lens 2 is located as the symmetry axis, and the angle of the plane reflective element 3 can be adjusted, wherein the symmetry axis is perpendicular to the plane where the ground is located. By adjusting the angle of the plane reflective element 3, or in other words, adjusting the angle between two symmetrically installed plane reflective elements 3, the shooting area (the first shooting area 5 and the second shooting area 6) can be adjusted according to the actual situation. The distance between them can meet the most reasonable speed measurement requirements.

The distance between the ends of the two plane reflective elements 3 close to the lens 2 is smaller than the distance between the ends of the two plane reflective elements 3 far away from the lens 2 .

The included angle between the two planar reflective elements 3 is 2θ, 10°<θ<80°, so that the distance between the shooting areas can be adjusted according to the actual situation to achieve the most reasonable speed measurement requirement.

The distance between the contact point of the plane reflective element 3 on both sides and the lens 2 is 1/6-2/3 of the length of the plane reflective element 3 . That is, the plane reflective element 3 is not directly in contact with the lens 2, but has a certain distance therebetween.

Image storage unit 11 and image output unit 12 are arranged in the camera 1, the output end of image storage unit 11 is connected with the input end of image output unit 12, the output end of image output unit 12 is connected with the input end of display unit 4, image storage Unit 11 is used for storing the front image and the rear image of the vehicle being photographed by the lens 2, and the image output unit 12 is used for outputting the front image and the rear image of the vehicle being photographed to the display unit 4, which can be The monitor in the control center or the large outdoor screen, or the display panel of the camera.

Also be provided with timing unit 13, calculation unit 14, data input unit 15 and data output unit 16 in camera 1, the output end of data input unit 15 and the output end of timing unit 13 are all connected with the input end of calculation unit 14, calculation unit The output end of 14 is connected with the input end of data output unit 16, and timing unit 13 is used for timing the time that the vehicle of being photographed passes through a certain area, and data input unit 15 is used for inputting the 3 angles of plane reflective element, and calculation unit 14 is used In order to calculate the length of a certain area according to the three angles of the plane reflective element, and calculate the speed of the vehicle being photographed, the data output unit 16 is used to output the calculated speed to other devices, such as the display of the control center, so as to monitor the operation of traffic situation or conduct traffic forensics.

During use, the present invention is installed on the top of the road section to be photographed, and when the vehicle to be photographed enters the first photographing area 5, the optical path passes through the lens 2 after being reflected by the plane reflective element 3, and enters the camera 1, thereby photographing and obtaining The front image of the captured vehicle is stored in the image storage unit 11 and then output to the display unit 4 through the image output unit 12 .

In the same way, when the vehicle to be photographed travels to the second shooting area 6, the back image of the vehicle to be photographed is recorded by the above method and stored in the image storage unit 11, and then output to the display unit through the image output unit 12 4.

In a word, the present invention has following advantages at least:

First, there is no need to increase the recording equipment, and the recording range can be increased on the basis of one camera 1, thereby increasing the utilization rate of resources and reducing the investment of capital and various resources.

Second, the present invention only needs to add a group of plane reflective elements 3 on the basis of the original video recording to achieve the purpose of recording the images of the front and rear of the vehicle, which takes up little space and is convenient for installation and debugging.

Third, without adding related supporting equipment, the speed measurement range can be increased, and the distance of the speed measurement range can be flexibly adjusted according to needs.

In a word, the present invention increases the angle-adjustable plane reflection element 3 groups at the front end of the lens 2 of the camera 1, thereby changing the light path entering the recording device, increasing the recording range on the basis of only one camera 1, and Small footprint. The method can obtain the images of the front and rear sides of the vehicle to be photographed, and solves the defects of the original traffic recording equipment.

Example 2

As shown in FIG. 3 , this embodiment provides a method for measuring speed using a lens structure of dual image capturing, including the following steps:

S1, install the present invention above the road section to be photographed, adjust the angle of the plane reflective element 3, and input the angle into the camera 1 through the data entry unit 15, and the computing unit 14 of the camera 1 calculates the first shooting area 5 and the second shooting area. The distance D between the two shooting areas 6, in Fig. 1, the distance D is the distance between the intersection of the leftmost ray and the ground and the intersection of the rightmost ray and the ground;

S2, when the front of the vehicle to be photographed enters the first shooting area 5 (that is, when the front end of the vehicle enters the leftmost light in Fig. 1), the light path of the front end of the vehicle is reflected by the plane reflective element 3, Enter the camera 1 through the lens 2, and the computing unit 14 starts counting until the back of the vehicle to be photographed will leave the second shooting area 6 (that is, when the rearmost end of the vehicle will leave the farthest light in Fig. 1 ) , at this time, the light path at the rear end of the vehicle passes through the lens 2 after being reflected by the plane reflective element 3, and then enters the camera 1, and the calculation unit 14 finishes timing, and the timing is T seconds;

S3, the calculation unit 14 calculates the vehicle speed, the vehicle speed V=D/T, and the data output unit 16 outputs the value of the vehicle speed to the control center.

Wherein, the calculation formulas of the length L of the first photographing area 5 and the second photographing area 6 are:

L=h×tan2θ-h×tan(2θ-FOV/2);

The calculation formula of the distance d1 (shortest distance) between the side edges that are close to each other of the first photographing area 5 and the second photographing area 6 is: d1=2h*tan(2θ-FOV/2);

The calculation formula of the distance d2 (farthest distance) between the side edges of the first photographing area 5 and the second photographing area 6 that are far away from each other is: d2=2h×tan2θ;

Wherein, θ is the angle between the plane reflective element 3 and the straight line where the central axis of the lens 2 is located, h is the height of the end of the plane reflective element close to the lens from the ground, and FOV is the camera field of view angle.

In a word, the present invention is simple and easy, and can quickly calculate the speed of the vehicle to be photographed, thereby solving the problem of the original speed measurement system with a small speed measurement range due to the limitation of the depth of field of the lens.

According to the disclosure and teaching of the above specification, those skilled in the art to which the present invention pertains can also make appropriate changes and modifications to the above embodiment. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims (8)

1. a slur is as the lens construction of capture, it is characterized in that: comprise camera, camera lens and two facial plane reflecting elements, described camera lens is arranged at the interface of described camera, plane reflecting element described in two sides with the central shaft place straight line of described camera lens for axis of symmetry is arranged at the front end of described camera lens symmetrically, and the angle adjustable of described plane reflecting element.

2. slur according to claim 1 is as the lens construction of capture, it is characterized in that: the distance between one end of the close described camera lens of plane reflecting element described in two sides be less than plane reflecting element described in two sides away from described camera lens one end between distance.

3. slur according to claim 1 is as the lens construction of capture, it is characterized in that: the angle described in two sides between plane reflecting element is 2 θ, 10 ° of < θ < 80 °.

4. slur according to claim 2 is as the lens construction of capture, it is characterized in that: the distance between the contact point of plane reflecting element described in two sides and described camera lens is 1/6 ~ 2/3 of the length of described plane reflecting element.

5. slur according to claim 1 is as the lens construction of capture, it is characterized in that: in described camera, be provided with image store unit and image output unit, the output terminal of described image store unit is connected with the input end of described image output unit, the described output terminal of image output unit is connected with the input end of display unit, described image store unit for storing before object vehicle being shot image and image below, described image output unit be used for by image before object vehicle being shot and below image output to display unit.

6. slur according to claim 1 is as the lens construction of capture, it is characterized in that: in described camera, be also provided with timing unit, computing unit, data entry element and data outputting unit, the output terminal of described data entry element is all connected with the input end of described computing unit with the output terminal of described timing unit, the output terminal of described computing unit is connected with the input end of described data outputting unit, described timing unit is used for carrying out timing to object vehicle being shot by the time in certain region, described data entry element is used for the angle of typing plane reflecting element, described computing unit is used for the length according to the angle calculation region of plane reflecting element, and calculate the speed of a motor vehicle of object vehicle being shot, described data outputting unit is used for exporting the speed of a motor vehicle calculated to other equipment.

7. use the slur described in claim 1 to carry out the method tested the speed as the lens construction of capture, it is characterized in that, comprise the following steps:

S1, regulates the angle of plane reflecting element, and by this angle input camera, camera calculates first and shoots with video-corder region and second and shoot with video-corder distance D between region;

S2, enters into first when shooting with video-corder region before object vehicle being shot, starts timing, until object vehicle being shot will sail out of second below when shooting with video-corder region, timing terminates, and timing is T second;

S3, calculates the speed of a motor vehicle, vehicle velocity V=D/T.

8. use slur according to claim 7 carries out the method that tests the speed as the lens construction of capture, it is characterized in that: described first shoots with video-corder region and described second computing formula of shooting with video-corder the length L in region is:

L＝h×tan2θ-[h×tan(2θ-FOV/2)]；

Described first shoot with video-corder shoot with video-corder region in region and described second a lateral edges close to each other between the computing formula of distance d1 be: d1=2h × tan (2 θ-FOV/2);

Described first shoot with video-corder that region and described second shoots with video-corder region mutual away from a lateral edges between the computing formula of distance d2 be: d2=2h × tan2 θ;

Wherein, θ is the angle between the central shaft place straight line of plane reflecting element and described camera lens, and h is one end height overhead of the close described camera lens of plane reflecting element, and FOV is viewing field of camera angle.