CN105423998A - Lens distance measurement device and measurement method thereof - Google Patents

Abstract

A lens distance measuring device and its measuring method, the device includes a frame, a lens and a CCD photosensitive element are installed in the frame, the lens is connected to a stepping motor through a moving device, the stepping motor is connected to the output end of a control board, and the CCD The output end of the photosensitive element is connected to the input end of the control board; point the device at the object to be measured, the mobile device will place the object under test in the central viewing frame of the display screen, and analyze the above image through the image detection module to determine whether the lens is in the best position. The position of the lens, that is, the position of the lens when the image is the clearest; the rotation direction of the stepping motor and the number of pulses are transmitted to the data processing module to calculate the image distance, and then pass 1/u+1/v=1/ f, obtain the object distance, that is, the distance of the measured object; the present invention has the characteristics of simple system, low cost, little influence by environmental factors during measurement, suitable for distance measurement of short-range stationary objects, and high measurement accuracy .

Description

A lens distance measuring device and its measuring method

technical field

The invention relates to the technical field of distance measurement, in particular to a lens distance measurement device and a measurement method thereof.

Background technique

Ranging devices are commonly used surveying and mapping instruments in engineering. Existing ranging devices such as ultrasonic ranging, traditional laser ranging, infrared ranging, etc., will be affected by factors such as the measurement environment and geographical conditions. Infrared distance measurement has low precision, short distance and poor directionality; laser distance measurement needs to pay attention to human safety, and it is difficult to manufacture, high cost, and the optical system must be kept clean, otherwise it will affect the measurement; although ultrasonic distance measurement can be used in poor environment, but its accuracy is low and the cost is high.

Contents of the invention

In order to overcome the above-mentioned existing deficiencies, the object of the present invention is to provide a lens distance measuring device and its measuring method. The lens distance measuring device using the Gaussian imaging formula has the advantages of simple system, low cost, and little influence by environmental factors during measurement. , suitable for distance measurement of short-range stationary objects, and has the characteristics of high measurement accuracy.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A lens ranging device, comprising a frame 1, a lens 2 and a CCD photosensitive element 4 are installed inside the frame 1, the CCD photosensitive element 4 is located in a dark room inside the frame 1, and the lens 2 passes through a moving device and a stepping motor 3 Connected, the stepper motor 3 is arranged on the upper end of the frame 1, the stepper motor 3 is connected to the output end of the control board 10, the output end of the CCD photosensitive element 4 is connected to the input end of the control board 10, and the output end of the control board 10 is connected to the display device .

The control board 10 includes a motor drive module 9, a data processing module 5, an image detection module 11 and a display module 12; the input end of the image detection module 11 is connected to the output end of the CCD photosensitive element 4, and the image detection module 11 The output end of the data processing module 5 is connected to the input end of the data processing module 5, and the output end of the data processing module 5 is respectively connected to the input end of the motor drive module 9 and the input end of the display module 12; the output end of the motor drive module 9 is connected to the stepper motor 3. The output terminal of the display module 12 is connected to the input terminal of the display device.

The display device includes a display screen 6 on which a viewfinder frame 13 is arranged, and a confirmation key 14 and an output key 15 are also installed on the display screen 6 .

The moving device includes a gear 8 connected with the stepping motor 3 , the gear 8 meshes with a rack mounted on the top of the frame 1 , and the lens 2 is connected with one end of the rack 7 .

A measurement method for lens distance measurement, at first, the measured object is imaged on the CCD photosensitive element 4 through the lens 2, and the image detection module 11 calculates the contrast of the image and records it in the data processing module 5; then, the data processing module 5 The signal of lens movement is sent, and the stepper motor 3 is driven by the motor drive module 9 to drive the lens 2 to move a specific distance in a certain direction. The displacement and direction of lens 2 movement are sent by the data processing module 5 to the pulse number and Determine the direction signal and record it in the data processing module 5; when the lens 2 moves to a new position, re-use the image detection module 11 to calculate the contrast of the image and record it in the data processing module 5, if the contrast improves after this movement , then the data processing module 5 sends a signal to control the lens 2 to continue to move in the same direction, and repeat the above steps, otherwise move the lens 2 in the opposite direction until the position of the lens 2 when the maximum contrast ratio is found; finally, the data processing module 5 calculates The number of pulses and the direction of rotation of the stepping motor 3, that is, the position of the lens 2 when the measured object can be clearly imaged, can calculate the distance v when the image is clearly imaged.

The stepping motor driving module 9 drives the stepping motor 3 to rotate by controlling the number of pulses and setting the direction according to the lens movement signal fed back by the data processing module 5 to adjust the position of the lens 2 .

Described data processing module 5 is divided into two parts, and a part is to record the contrast value in the image detection module 11, by comparing the contrast value, sends the signal of lens movement, seeks out the imaging when optimal contrast; Another part is record stepping The direction of rotation of the motor 3 and the number of pulses of operation are calculated to obtain the image distance v during clear imaging, and then through 1/u+1/v=1/f, the distance u of the measured object is finally obtained;

The display module 12 displays the image of the object to be measured on the display panel 6 to facilitate selection of the object to be measured, and displays the final measurement distance.

Beneficial effects of the present invention:

The invention has the advantages of simple structure, low cost and little influence of environmental factors during measurement, and is suitable for distance measurement of short-range stationary objects with high measurement accuracy, and can simultaneously complete distance measurement and monitoring in combination with a camera.

Description of drawings

Fig. 1 is a schematic diagram of the principle of the present invention.

Fig. 2 is a structural schematic diagram of the present invention.

Fig. 3 is a schematic diagram of the workflow of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figure 2, a lens distance measuring device includes a frame 1, a lens 2 and a CCD photosensitive element 4 are installed inside the frame 1, and the CCD photosensitive element 4 is located in a dark room inside the frame 1, and the lens 2 moves through the The device is connected with the stepping motor 3, the stepping motor 3 is arranged on the upper end of the frame 1, the stepping motor 3 is connected with the output end of the control board 10, the output end of the CCD photosensitive element 4 is connected with the input end of the control board 10, and the control board 10 The output terminal is connected to the display device.

The control board 10 includes a motor drive module 9, a data processing module 5, an image detection module 11 and a display module 12; the input end of the image detection module 11 is connected to the output end of the CCD photosensitive element 4, and the image detection module 11 The output end of the data processing module 5 is connected to the input end of the data processing module 5, and the output end of the data processing module 5 is respectively connected to the input end of the motor drive module 9 and the input end of the display module 12; the output end of the motor drive module 9 is connected to the stepper motor 3. The output terminal of the display module 12 is connected to the input terminal of the display device.

The display device includes a display screen 6 on which a viewfinder frame 13 is arranged, and a confirmation key 14 and an output key 15 are also installed on the display screen 6 .

The moving device includes a gear 8 connected with the stepping motor 3 , the gear 8 meshes with a rack mounted on the top of the frame 1 , and the lens 2 is connected with one end of the rack 7 .

As shown in Figure 3, a kind of measurement method of lens ranging, at first, measured object is imaged on CCD photosensitive element 4 by lens 2, and image detection module 11 calculates the contrast of image and records in data processing module 5; Then , the lens movement signal is sent by the data processing module 5, and the stepper motor 3 is driven by the motor drive module 9 to drive the lens 2 to move a specific distance in a certain direction, and each time the lens sends a signal, the motor drive module outputs a given number of pulses, Then the rotation angle of the stepping motor is a constant value, that is, the distance that the lens moves is a constant value. Then re-use the image detection module 11 to calculate the contrast of the image and record it in the data processing module 5. If the contrast is improved after this movement, the data processing module will send a signal to move the lens, continue to drive the motor to move a specific distance and repeat the above steps , otherwise move the lens in the opposite direction until the position of the lens when the maximum contrast ratio is found; finally, the number of pulses and the direction of rotation of the stepper motor are calculated through the data processing module 5, that is, the position of the lens 2 when the measured object can be clearly imaged .

The stepping motor driving module 9 drives the stepping motor 3 to rotate by controlling the number of pulses and setting the direction according to the lens movement signal fed back by the data processing module 5 to adjust the position of the lens 2 .

Described data processing module 5 is divided into two parts, and a part is to record the contrast value in the image detection module 11, by comparing the contrast value, sends the signal of lens movement, seeks out the imaging when optimal contrast; Another part is to record into motor The rotation direction of 3 and the number of operating pulses can be used to calculate the image distance v for clear imaging, and then pass 1/u+1/v=1/f to finally obtain the distance u of the measured object;

The display module 12 displays the image of the object to be measured on the display panel 6 to facilitate selection of the object to be measured, and displays the final measurement distance.

Working principle of the present invention:

As shown in Figure 3: Step 1: aim the lens distance measuring device at the object to be measured, move the lens distance measuring device to place the measured object in the central viewfinder frame 13 of the display screen 6, and then press the confirmation key 14;

Step 2: analyze the above-mentioned image through the image detection module 11, and judge whether the lens 2 is in the best position, that is, the position of the lens 2 when the imaging is the clearest; if not, then send a signal to move the lens;

Step 3: The stepper motor drive module 9 drives the stepper motor 3 to rotate by controlling the number of pulses and setting the direction according to the lens movement signal fed back by the data processing module 5, and adjusts the position of the lens 2 .

Step 4: Repeat Step 2 and Step 3 until the clearest image of the measured object is obtained on the CCD photosensitive element 4;

Step 5: Utilize the rotation direction and the number of pulses of each stepper motor 3 recorded in the data processing module 5 to calculate the displacement of the lens 2 and obtain the image distance v, and then pass 1/u+1/v=1/f, Get the object distance u, that is, the distance of the measured object, where: u is the object distance, v is the image distance, and f is the focal length;

Step 6: Finally, press the output key 15 to output the distance of the measured object on the display screen 6 .

Claims (5)

1. a lens distance measuring equipment, comprise frame (1), camera lens (2) and CCD photo-sensitive cell (4) are installed in frame (1) inside, CCD photo-sensitive cell (4) is arranged in the inner darkroom of frame (1), it is characterized in that, camera lens (2) is connected with stepper motor (3) by mobile device, stepper motor (3) is arranged on frame (1) upper end, stepper motor (3) is connected with the output terminal of control panel (10), the input end of the output terminal connection control plate (10) of CCD photo-sensitive cell (4), the output terminal of control panel (10) connects display device.

2. a kind of lens distance measuring equipment according to claim 1, it is characterized in that, in described control panel (10), comprise motor drive module (9), data processing module (5), image detection module (11) and display module (12); The input end of described image detection module (11) connects the output terminal of CCD photo-sensitive cell (4), the input end of the output terminal connection data processing module (5) of image detection module (11), the output terminal of data processing module (5) connects the input end of motor drive module (9) and the input end of display module (12) respectively; The output terminal of described motor drive module (9) connects stepper motor (3), and the output terminal of display module (12) connects the input end of display device.

3. a kind of lens distance measuring equipment according to claim 1, it is characterized in that, described display device comprises display screen (6), display screen (6) is provided with view-finder (13), display screen (6) is also provided with acknowledgement key (14) and run-out key (15).

4. a kind of lens distance measuring equipment according to claim 1, it is characterized in that, described mobile device comprises the gear (8) be connected with stepper motor (3), gear (8) is meshed with the tooth bar being arranged on frame (1) top, and camera lens (2) is connected with one end of tooth bar (7).

5. based on a kind of lens distance-finding method of device described in the arbitrary claim of Claims 1-4, it is characterized in that, first, testee is by camera lens (2) in the upper imaging of CCD photo-sensitive cell (4), and image detection module (11) calculates the contrast of image and is recorded in data processing module (5); Then, the signal of lens moving is sent by data processing module (5), camera lens (2) is driven to move specific distance to certain direction by motor drive module (9) Driving Stepping Motor (3), the displacement of camera lens (2) movement and direction send to the umber of pulse of motor drive module (9) and direction signal to determine by data processing module (5), and are recorded in data processing module (5); After camera lens (2) moves to reposition, re-use the contrast of image detection module (11) computed image and be recorded in data processing module (5), if contrast promotes after this movement, then send signal control camera lens (2) by data processing module (5) to continue to move to equidirectional, and repeat above-mentioned steps, otherwise moving lens (2) round about, until the position of camera lens (2) when finding contrast maximal value; Finally, the umber of pulse rotated by data processing module (5) calculated step motor (3) and the direction of rotation, namely testee can blur-free imaging time camera lens (2) position;

Camera lens (2) movable signal that described driving stepper motor module (9) is fed back according to data processing module (5), Driving Stepping Motor (3) running is carried out, the position of adjustable lens (2) by the number of gating pulse and direction initialization;

Described data processing module (5) is divided into two parts, and a part is the contrast value in record image detection module (11), by comparing contrast value, sending the signal of lens moving, finding out imaging during optimum contrast; Another part is the pulse number recording sense of rotation into motor (3) and running, calculates image distance v during blur-free imaging, then by 1/u+1/v=1/f, finally draws the distance u of testee;

The image of testee is shown the object being convenient to select to measure by described display module (12) in display Folding-Screen (6), and is shown by final measuring distance.