CN102278972A

CN102278972A - Digital laser range finder capable of video capture

Info

Publication number: CN102278972A
Application number: CN2011101574071A
Authority: CN
Inventors: 王宁会; 吴彦; 李国锋; 付友
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2011-06-03
Filing date: 2011-06-03
Publication date: 2011-12-14

Abstract

The invention provides a digital laser range finder capable of video capture, which belongs to the technical field of calculation, control and instrument testing. The invention is characterized in that: based on the physiological phenomenon of human eyes that an object is big when seen closely while small when seen at a distance and the characteristic that laser is not easy to diverge, two semiconductor lasers are utilized to emit two parallel light beams onto an object to be measured, a camera is used to capture images, the difference between pixel positions of two laser points is calculated with a one-chip microcomputer, and the pixel position difference is compared with real distance between the two laser beams so as to calculate actual distance between the measured object and the camera. The main technical advantages of the invention are as follows: the digital laser range finder has a weight no less than 1 kg, a measuring range about 1 m, measuring precision within 1 cm and a display function, and the manufacture cost for the digital laser range finder is about 200 RMB. The effects and benefits of the invention are as follows: low cost, a great measuring range, high precision, convenient usage and great competitive advantages and profit space in aspects of manufacture cost, product performance and convenience of usage.

Description

The digital laser range finder that has the video acquisition function

Technical field

The invention belongs to calculating, control and Meter Test technical field, relate to a kind of digital laser range finder that has the video acquisition function.

Background technology

Volume is little, the precision advantages of higher because of it has for semiconductor laser range instrument, is widely used in fields such as industrial automatic assembly line, robot vision, military affairs, space flight.Present more popular on the market semiconductor laser range instrument mainly contains pulsed and phase type is two kinds.The former principle is comparatively simple, but about 1 meter of precision low resolution mainly is applicable to the large range measuring of km; Latter's precision is higher, but complex structure is with high costs, reaches several ten thousand yuans, and upward the high pressure of hectovolt is added on the laser sensor, causes its volume bigger, and weight is heavier, is not easy to carry and install.

Summary of the invention

The objective of the invention is the low and high defective of price of precision in the market laser range finder, a portable laser stadimeter is provided, its weight is less than 1kg; About 1 meter of range; Measuring accuracy is in 1cm; Have Presentation Function, and manufacturing cost is lower.

Technical scheme of the present invention is to utilize human eye to watch near big and far smaller this physiological phenomenon of object, and the characteristic of utilizing laser to be difficult for dispersing.The laser instrument that is parallel to each other with two positions is launched two bundle directional lights and is impinged upon on the testee, by the camera collection image that is positioned at these two laser instrument middles, by the color screen that is positioned at the camera back side image information that laser impinges upon on the testee is shown to the user qualitatively, calculate the poor of location of pixels that two laser spots show with single-chip microcomputer on screen, its actual distance with two bundle laser is compared, thereby extrapolate the actual range of testee apart from camera, computing formula is: m=k * (d/l).M is the distance of testee apart from camera; D is the actual distance of two bundle laser; L is position poor of two laser spots showing on the screen; K is a proportionality constant, and under the situation apart from m of camera, (m * l)/d calculates by formula k=at known testee.

Build circuit according to the schematic diagram among Fig. 1, and press Fig. 2, the structure of Fig. 3 is drawn pcb board, camera chip, and color screen, single-chip microcomputer, crystal oscillator, latch, four input nand gates, the voltage stabilizing chip is above being welded on.

When two laser heads are installed, should guarantee that the laser that they send is parallel to each other.The present invention adopts following method:

Step 1

When drawing PCB, the pad that two ordinate positions equate is set on drawing, internal diameter is than the big 0.5mm of diameter of laser head.

Step 2

When mounted, with the energising of two laser heads, draw two points on the plane at 4-5m place, distance stadimeter dead ahead, its distance equals home position poor of the pad of two placement laser heads, and that the model machine of making is got is 30.1456mm.Then laser head is placed on the pad, hot melt adhesive is fixed on the point, and the angle of two laser heads of fine setting makes two points finishing in advance on its alignment surface when hot melt adhesive is uncolled, thereby guarantees that the laser that sends is parallel in range ability.

Be the input ranging procedure afterwards, its algorithm is: begin latch is opened, camera is delivered to color screen with the image that the laser beam that collects impinges upon on the testee, then latch cuts out, single-chip microcomputer scans the rgb value of each point with a loop statement, and with the rgb value of itself and laser spots, 0XFFFF compares, if equate, then in internal memory, note this locations of pixels, determine the position of laser spots, after loop ends, the position of two laser spots is subtracted each other, utilize formula m=k * (d/l), calculate the actual range of camera to testee.After the energising, this stadimeter just can have been worked.

Effect of the present invention and benefit are that cost is low, range is big, and precision is high and easy to use, all shows competitive edge and profit margin at aspects such as manufacturing cost, properties of product and eases of use.

Description of drawings

Fig. 1 is the circuit theory diagrams of laser range finder.

Fig. 2 is the pcb board front view of laser range finder.

Fig. 3 is the pcb board rear view of laser range finder.

Among Fig. 1-Fig. 3: D2, D3 laser head; The P3 camera; The P4 color screen; The U4 single-chip microcomputer; U3 4 input nand gates; The P4 color screen; The U5 latch.

Fig. 4 is the model machine photo figure of laser range finder.

Embodiment

Be described in detail the specific embodiment of the present invention below in conjunction with technical scheme and accompanying drawing.

Embodiment

As the laser range finder model machine in the picture 4, it is as follows that it makes required main element: diameter is 2 of the semiconductor laser heads of 6mm, one of OV7670 camera chip, one of the color screen that ILI9325 drives, PIC18F452 single-chip microcomputer a slice, one of 16M crystal oscillator, 74HC244 latch one plain film, 74H,C20 four input nand gate a slices, ASM1117-3.3 voltage stabilizing chip a slice, PAM3101 2.8V voltage stabilizing chip a slice, one of 3.6V lithium battery.

Its main circuit connects as Fig. 1, power unit: by ASM1117-3.3 with the 3.6V voltage step-down to 3.3V, by PAM3101 3.3V voltage is dropped to 2.8V again; Video acquisition part: by camera the view data that collects is passed on the color screen by latch 74HC244 by 8 data lines and to show; Image processing section, ILI9325 has preserved image information and has been scanned the rgb value of pixel in the color screen by 8 data lines by single-chip microcomputer.Four input nand gate 74HC20 wherein are responsible for coordinating single-chip microcomputer and the camera chip OV7670 use to bus.

The pcb board figure of circuit is referring to Fig. 2 and Fig. 3, make pcb board according to Fig. 2 and Fig. 3, with the laser head among Fig. 1, the OV7670 camera chip, the color screen that ILI9325 drives, the PIC18F452 single-chip microcomputer, the 16M crystal oscillator, the 74HC244 latch, 74H,C20 four input nand gates, ASM1117-3.3 voltage stabilizing chip, PAM3101 2.8V voltage stabilizing chip, resistance, electric capacity, switch, above connection terminal is welded on, in Fig. 2, add the 3.6V DC voltage on the P1 port, positive pole connects the terminal that indicates "+", for single-chip microcomputer writes initialize routine and ranging procedure, stadimeter just can have been worked.The kernel program of its range finding is as follows:

The precision of stadimeter depends on the pixel quantity of camera and color screen, according to this kind configuration, i.e. and 240 * 320 stadimeters that pixel is made, its range can reach 1.2m, and distance accuracy is 1cm.

Claims

1. the digital laser range finder that has the video acquisition function, it is characterized in that launching two bundle directional lights with the laser instrument that two positions are parallel to each other impinges upon on the testee, by the camera collection image that is positioned at these two laser instrument middles, by the color screen that is positioned at the camera back side image information that laser impinges upon on the testee is shown to the user qualitatively, calculate the poor of location of pixels that two laser spots show with single-chip microcomputer on screen, its actual distance with two bundle laser is compared, thereby extrapolate the actual range of testee apart from camera, computing formula is: m=k * (d/l), m is the distance of testee apart from camera; D is the actual distance of two bundle laser; L is position poor of two laser spots showing on the screen; K is a proportionality constant, and under the situation apart from m of camera, (m * l)/d calculates by formula k=at known testee.