CN202404111U - DSP-based video velocity-measuring system - Google Patents
DSP-based video velocity-measuring system Download PDFInfo
- Publication number
- CN202404111U CN202404111U CN2011204588601U CN201120458860U CN202404111U CN 202404111 U CN202404111 U CN 202404111U CN 2011204588601 U CN2011204588601 U CN 2011204588601U CN 201120458860 U CN201120458860 U CN 201120458860U CN 202404111 U CN202404111 U CN 202404111U
- Authority
- CN
- China
- Prior art keywords
- video
- dsp
- measuring system
- chip
- measuring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Image Processing (AREA)
Abstract
A DSP-based video velocity-measuring system is provided. The system comprises a signal acquisition unit, a video decoder, a data buffer memory channel, a DSP processing module, a video encoder and an interface unit which are successively connected in series. The system is a high-tech novel optical, mechanical and electronic integrated system which is based on theories of computer vision and mode identification, and combined with a plurality of engineering science standards. The design idea of utilizing video signals to measure a certain object is an exploration with scientific perspective, productization has greater meanings, and lots of problems of contact type and non-contact type measuring are solved. Compared with the prior art, the DSP chip based video velocity-measuring system with a velocity measuring function can be used for measuring vehicle speed in a high dynamic environment, has wide application prospects in the vehicle speed measuring aspect, and has great production and practical meanings.
Description
Technical field
The utility model relates to the measuring vehicle speed technical field, is specifically related to the method that a kind of DSP of utilization technology realizes the video measuring speed of a motor vehicle.
Background technology
At present, the method that in the existing intelligent transportation system vehicle is tested the speed mainly contains that coil tests the speed, laser velocimeter, radar velocity measurement etc.Inductive coil tests the speed, and can only be used for fixing a monitoring, and measuring repeatability is lower, and data fluctuations property is bigger, and road pavement has certain destruction; The principle of work of laser velocimeter is to be based upon on the basis of light wave range finding, utilizes the repeatedly range finding of moving object and the ratio of time, draws its movement velocity, and the laser velocimeter method requires all very high to the angle that tests the speed, in practice, have certain limitation.The hand-held radar meter, personal error is bigger, does not have illegal evidence acquisition function; The part radar meter, microwave launching beam broad is prone to surveyed anti-interference poor effect by cyberdog.Above-mentioned in addition method of testing can not be real-time transmitted to on-the-spot punishment point, for on-site law-enforcing brings very big inconvenience.
Summary of the invention
The purpose of the utility model is to overcome the above-mentioned deficiency that prior art exists; A kind of video frequency speed-measuring system based on DSP is provided; Can realize fast, in real time moving target carried out velocity survey, not only can carry out velocity survey, but also can carry out velocity survey multilane to the bicycle road; Help reducing production costs, be of great practical significance.
The video frequency speed-measuring system based on DSP that the utility model provides comprises signal gathering unit, Video Decoder, metadata cache passage, DSP processing module, video encoder and the interface unit of serial connection successively.
Signal gathering unit is ccd image sensor, is used to gather the image that comes from the external world, and it is passed to Video Decoder; The inner principle of work of CCD is in the ccd image sensor, and the signal charge of each photosensitive unit passes to the shifting deposit unit on the corresponding positions simultaneously, and then is sent on the video output cable through displacement successively.
Video Decoder is used for the analog video image signals that is collected is transformed into digital video signal, and is sent to the metadata cache passage; Comprise input circuit and video decoding chip; But input circuit is the analog front circuit of filtering; Video decoding chip; Select chip VP5150 video decoding chip for use; It is the high performance mixed signal Video Decoder of TI company; Can the analog video signal of standard be converted to the digital video signal of standard, and be connected, can accept input of two-way composite video signal and the input of one road super video signal with input circuit.
The metadata cache passage; Be a kind of storer of first in first out, promptly the FIFO device is used for the digital video signal that the receiver, video demoder is sent; Solve between DSP processing module and the Video Decoder because the sequential matching problem that speed difference causes passes to the DSP processing module with it then; Video Decoder is as the peripheral hardware in the system, and speed is too slow with respect to dsp chip, behind the employing FIFO storer; The data that can send Video Decoder earlier are sent to the FIFO storer; In case after reaching the data volume of FIFO storer setting, the FIFO storer sends to DSP and interrupts application, has saved DSP like this and has spent in the time of waiting for and inquiring about; Interruption times also is able to reduce, thereby has improved bulk velocity.
The DSP processing module is the DSP microprocessor chip, realizes the selection to passage through the selection of pin and the programming of software, and to the judgement arithmetic operation of data.Be used to receive the digital video signal that the metadata cache passage is exported, and adopt the frame difference method that target is detected, adopt the Kalman filtering track algorithm to come vehicle is followed the tracks of.Confirm many marks of the pixel of required frame image according to detected movement locus; Through the location drawing picture of definite different frame moving object and the mistiming of interframe; Utilize the conversion of image coordinate and world coordinates, can obtain the actual range of moving target, thereby obtain the speed of moving target.
Video encoder is used for the handled data message of encoding D SP processing module, comprises output circuit and video coding chip; But output circuit is the analog output circuit of filtering, is the front end circuit of scrambler; Described video coding chip adopts the SAA7105H chip, supports the video coding output of PAL and NTSC form; It is 1208 * 1024 VGA video output that resolution can be provided simultaneously, can directly drive the PC display; The HD video output of ultimate resolution 1920 * 1080P.
Interface unit is used for handled data message is sent in the middle of the computing machine.
Signal gathering unit: use camera as image capture device, the simulating signal of camera output is the mixed signal of luminance signal and synchronizing signal, and wherein luminance signal is the original input of picture signal; Synchronizing signal is used to control the collection of view data after being separated by video decoding chip.
Video input is handled: this part adopts integrated video decoding chip, converts analog video signal to digital video signal, exports the pixel clock of from analog video signal, isolating synchronizing signal and being produced by the clock generator of chip internal simultaneously.Video input process chip is accomplished initialization operation by DSP through interface.
Metadata cache FIFO: this partial action is accomplish view data temporary, solves between DSP and the video decoding chip because the sequential matching problem that speed difference causes.
Processing module: what this part adopted is dsp chip at a high speed, and digital video signal is carried out relevant treatment.Because image data amount is bigger, so select for use the bigger and lower-cost SDRAM of capacity to store data.This SDRAM is articulated to the CEO space of DSP through the EMIF bus.Adopt the procedure stores of FLASH, the application program that is used to solidify DSP.FLASH has been assigned to the CEI space of DSP.
Video output is handled: this part adopts the integrated video coding chip, accomplishes the collection and the recovery of view data.Video output process chip is accomplished initialization operation by DSP through interface.
Communication interface: this part is used for to upper PC transmitted image data or processing result image, adopts the serial bus interface chip to realize the serial communication between system and the PC.
Advantage of the utility model and beneficial effect:
Video frequency speed-measuring is to be theoretical foundation with technology such as Flame Image Process, computer vision, pattern-recognitions, through handling, analyzing, extract the information of vehicles in the video image, finally change into vehicle on real road information and reach the purpose that tests the speed.Along with the tremendous development and the widespread use of Flame Image Process, computer vision technique, the video frequency speed-measuring technology receives extensive concern as the important component part of intelligent transportation system, and oneself becomes popular research topic.Video frequency speed-measuring other speed-measuring methods relatively has following advantage:
1, equipment is installed and need not to destroy the road surface, and is prone to installation, easy care;
2, cost is low, anti-electronic interferences, and long service life, and also extendability is strong, is beneficial to secondary development;
That 3, excavates contains much information, and can carry out the parallel of multilane, many vehicles and test the speed;
The data of 4, gathering are easy to storage, help analysis afterwards greatly and handle.
Compared with prior art; The video frequency speed-measuring system that the utility model provides with speed measuring function based on dsp chip; Can be under the dynamic environment of high measured automobiles speed, and lead to having broad application prospects aspect the car speed measurement, be of great practical significance.
Description of drawings
Fig. 1 is the structural representation of a kind of video frequency speed-measuring system based on DSP provided by the invention;
But Fig. 2 is the analog front circuit figure of the filtering of a kind of Video Decoder provided by the invention;
But Fig. 3 is the pattern output circuit of the filtering of a kind of video encoder provided by the invention;
Fig. 4 is the concrete composition structural representation of a kind of video frequency speed-measuring system based on DSP provided by the invention;
Fig. 5 is the concrete synoptic diagram of the improved symmetric difference method of a kind of employing provided by the invention.
Embodiment
One, based on the structure of the video frequency speed-measuring system of DSP
As shown in Figure 1, comprise signal gathering unit 101, Video Decoder 102, metadata cache path 10 3, DSP processing module 104, video encoder 105 and the interface unit 106 of serial connection successively.
Wherein:
This signal gathering unit 101 generally is a ccd image sensor;
In the said ccd image sensor 101, the signal charge of each photosensitive unit passes to the shifting deposit unit on the corresponding positions simultaneously, and then is sent on the video output cable through displacement successively.
In the utility model; The main technical requirements of above-mentioned ccd image sensor 101 is: 512 * 512 pixel frame transfer visible light CCD; Its pixel dimension is 4 μ m * 4 μ m, and total pixel number is 231 (H) * 217 (V), and resolution is horizontal 200TV line; Vertical 160TV line (all being theoretical value), power consumption 5mW.
But Fig. 2 is the analog front circuit figure of the filtering of a kind of Video Decoder provided by the invention.
Referring to Fig. 2, this circuit diagram can carry out filtering with digital video signal, and can provide Video Decoder required incoming level.
In the utility model, as shown in Figure 4, Video Decoder 102 comprises input circuit 1021 and video decoding chip 1022, wherein:
Said input circuit 1021, but the analog front circuit of filtering;
Said video decoding chip 1022; Select a high performance video decoding chip for use; Can the analog video signal of standard be converted to the digital video signal of standard, and be connected, can accept input of two-way composite video signal and the input of one road super video signal with input circuit 1021;
In the utility model, the outer video signal input range is generally 1VPP, so must the input range of vision signal be adjusted to and the corresponding to vision signal input range of video decoding chip before using.
Metadata cache path 10 3; Be connected with Video Decoder 102; Be used for the digital video signal that receiver, video demoder 102 is sent, solve between DSP processing module 104 and the Video Decoder 102 because the sequential matching problem that speed difference causes passes to DSP processing module 104 with it then;
In the utility model, said metadata cache path 10 3 is storeies of a kind of first in first out, and Video Decoder 102 is as the peripheral hardware in the system; Relatively and dsp chip speed too slow; After adopting the FIFO storer, the data that can send Video Decoder earlier are sent to the FIFO storer, in case after reaching the data volume of FIFO storer setting; The FIFO storer sends to DSP and interrupts application; Saved DSP like this and spent in the time of waiting for and inquiring about, interruption times also is able to reduce, thereby has improved bulk velocity.
Need to prove, in the utility model, the following aspects is mainly considered in the selection requirement of FIFO device: adopt synchronously or asynchronous FIFO FIFO frequency of operation, the FIFO degree of depth and wide.Because synchronization fifo just progressively replaces asynchronous FIFO at the design aspect of FIFO with his quick and easy to operate advantage, therefore adopts synchronous FIFO, with the interface employing asynchronous system of DSP.
In the utility model, said DSP processing module 104 is microprocessor, and microprocessor mainly is that the programming through software realizes to the selection of passage and to the operations such as judgement computing of data.
In the utility model, the performance of microprocessor unit has fundamental influence to the treatment of picture performance.Generally speaking, microprocessor performance is high more, and Flame Image Process good more, rapid more is suitable for practical application more.
The processing module 104 of the utility model is preferably and adopts DSP microprocessor, this microprocessor to have performance height, volume is little, low in energy consumption, cost is low characteristics, thereby selects the DSP microprocessor to design the video frequency speed-measuring system of the utility model.
But Fig. 3 is the pattern output circuit of the filtering of a kind of video encoder provided by the invention.
Referring to Fig. 3, this circuit diagram can carry out filtering with the signal that video encoder is handled well.
In the utility model, video encoder 105 comprises output circuit 1051 and video coding chip 1052, wherein:
Said input circuit 1051, the front end circuit of video encoder, but the pattern output circuit of filtering;
Said video coding chip, it is 1280 * 1024 VGA video output that resolution can be provided simultaneously, can directly drive the PC display; The HD video output of ultimate resolution 1920 * 1080P.
Two, the detection and the track algorithm that relate to of video frequency speed-measuring system:
Moving object detection rudimentary algorithm: frame-to-frame differences point-score, background subtraction point-score and optical flow method.The frame-to-frame differences point-score is to utilize the image difference of two continuous frames in the sequence of video images or several frames to carry out motion detection.The background subtraction point-score is to utilize the difference of current frame image and background image to detect the moving region.The ultimate principle that optical flow method detects moving target is through giving a velocity for each pixel in the image, thereby forms an image motion field.
This paper chooses with a kind of improvement algorithm of frame-to-frame differences point-score as the basis, carries out the basic algorithm of moving object detection as this paper.This algorithm with the frame-to-frame differences point-score as the basis; And combine improved symmetric difference point-score and shadow casting technique to come moving target is located and the zone selection fast; Real-time; Receive the influence of change of external conditions little, target also has good detection effect for moving slowly, has overcome traditional algorithm in a certain respect deficiency.Introduce this algorithm below in detail.
If the grayscale image sequence of input does
F＝{f
k(x，y)，x≤N，y≤M，k＝0，1，2，...}
(x y) is the coordinate of a pixel in N * M pixel space, f in the formula
k(x y) is (x, gray-scale value y) in the k two field picture.
On the basis of acquisition sequence image, image is carried out the tense difference, to confirm the moving target region, establishing the difference sequence image is D, it is defined as
D＝{d
k(x，y)，x≤M，k＝0，1，2...}
D in the formula
k(x, y) be in the k frame difference image (x, gray-scale value y) can know according to the inter-frame difference ratio juris,
d
k(x，y)＝|f
k(x，y)-f
k-1(x，y)|
Through selecting suitable threshold that difference image is carried out binaryzation, can the difference image sequence be converted into the bianry image sequence.
R＝{r
k(x，y)，x≤N，y≤M，k＝0，1，2，...}
Fig. 3 is improved symmetric difference method.When background disturbance or target travel occur when slow, the difference result image just can not be confirmed the position of moving target exactly, adopts improved symmetric difference method for this reason.
1) adopt the method for interval n frame to carry out symmetric difference to adapt to the target of slow motion, this paper gets n=2;
2) difference image of consecutive frame is handled after again with, and then the symmetric difference image carried out aftertreatment, remove most of hole and breach.
The rudimentary algorithm of motion target tracking: track algorithm commonly used can be divided into: the tracking of based target outline, the tracking of based target characteristic matching, the tracking of based target zone coupling etc.This paper adopts a kind of improved motion target tracking algorithm based on Kalman filter.
The fundamental equation of Kalman filtering,
Kalman filter is to discrete time random signal x ∈ R
nEstimate that its signal model can be expressed as through model equation:
X(k)＝AX(k-1)+BU(k)+W(k)
Measured value z ∈ R
m, the measurement equation is:
Z(k)＝HX(k)+V(k)
In the following formula, X (k) is a predicted value of k system state constantly, and U (k) is the controlled quentity controlled variable of the k moment to system.A and B are systematic parameters, and for the multi-model system, A and B are matrix.Z (k) is a k measured value constantly, and H is the parameter of measuring system, and for many measuring systems, H is a matrix.W (k) and V (k) represent the noise of forecasting process and measurement respectively, suppose that usually they are separate, and their probability distribution is:
p(W)：N(0，Q)
p(V)：N(0，R)
With Kalman filter each moving target is followed the tracks of in the literary composition, ignored under the ideal situation of interference, assert that vehicle moves with uniform velocity, its state variable is described with the vector of 4 degree of freedom:
X(k)＝(x，y，V
x，V
y)
T
Wherein, x, y be respectively current k constantly the moving target center at x, the position on the y axle, V
x, V
yBe respectively moving target at x, the speed on the y direction of principal axis.
The measurement vector does
Z(k)＝(x
s(k)，y
s(k)，V
xs(k)，V
ys(k))
T
X wherein
s(k), y
s(k) represent moving target center that current k observes in the present frame constantly respectively at x, the coordinate components on the y axle, V
Xs(k), V
Ys(k) represent moving target center that current k observes in the present frame constantly respectively at x, the speed component on the y axle.
During the Kalman filter initialization, when promptly algorithm detected a new moving target and gets into scene, first frame detected the moving target position (x that obtains
0, y
0), replace the x in the filter status equation, y; The V of moving target
x, V
yCan be set to 0.
The state equation of Kalman filter is:
x(k+1)＝x(k)+V
x(k)Δt+Q
x(k)
x(k+1)＝x(k)+V
x(k)Δt+Q
x(k)
Wherein, x (k+1) is respectively next speed at moving target center constantly.
The observation equation of its observed quantity is:
x
s(k)＝x(k)+R
x(k)
y
s(k)＝y(k)+R
y(k)
V
xs(k)＝V
x(k)+R
x(k)
V
ys(k)＝V
y(k)+R
y(k)
Utilize the target location and the match search of prediction to confirm the position of target,, so just can think that detected target is exactly the target of being followed the tracks of, and can save object matching if in the hunting zone, have only a moving target.Under the situation of a more than target, to confirm tracked target at search area memory according to the minimum distance criterion of template matches.Search behind the moving target template and the position coordinates that will upgrade the moving target of following the tracks of according to current new target image and target location.
Camera calibration, we use a kind of simple and practical scaling method here, need not confirm any parameter of video camera, through demarcating the function curve of confirming road surface distance and image pixel distance, utilize linear interpolation to confirm the actual range of non-calibration point.Demarcation is under the static situation of video camera, to carry out, and utilizes video camera to be calibrated to take the set of diagrams picture, and the target in every width of cloth image and the actual range of video camera are measured in advance.Utilize method manual or that detect automatically to confirm the pixel distance of target distance from bottom image bottom, thereby obtain the function curve of actual range and pixel distance, certainly spacing distance is reduced, increase to demarcate and count, can improve distance measuring precision.When carrying out the vehicle range finding, obtain the pixel distance of vehicle bottom automatically through vehicle detecting algorithm to the image bottom, can directly obtain actual range for calibration point, but not the actual range of calibration point adopts approach based on linear interpolation to confirm.
The above only is the preferred implementation of the utility model; Should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model principle; Can also make some improvement and retouching, these improvement and retouching also should be regarded as the protection domain of the utility model.
Claims (6)
1. the video frequency speed-measuring system based on DSP is characterized in that this system comprises signal gathering unit, Video Decoder, metadata cache passage, DSP processing module, video encoder and the interface unit of serial connection successively.
2. the video frequency speed-measuring system based on DSP according to claim 1 is characterized in that described signal gathering unit is a ccd image sensor.
3. the video frequency speed-measuring system based on DSP according to claim 1 is characterized in that described Video Decoder comprises input circuit and video decoding chip;
But described input circuit is the analog front circuit of filtering;
Described video decoding chip is selected chip VP5150 for use, is the high performance mixed signal Video Decoder of TI company.
4. the video frequency speed-measuring system based on DSP according to claim 1 is characterized in that described metadata cache passage is a kind of storer of first in first out, i.e. the FIFO device.
5. the video frequency speed-measuring system based on DSP according to claim 1 is characterized in that described DSP processing module is the DSP microprocessor chip.
6. the video frequency speed-measuring system based on DSP according to claim 1 is characterized in that described video encoder comprises output circuit and video coding chip;
But described output circuit is the analog output circuit of filtering, is the front end circuit of scrambler;
Described video coding chip adopts the SAA7105H chip, supports the video coding output of PAL and NTSC form; It is 1208 * 1024 VGA video output that resolution can be provided simultaneously, can directly drive the PC display; The HD video output of ultimate resolution 1920 * 1080P.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204588601U CN202404111U (en) | 2011-11-18 | 2011-11-18 | DSP-based video velocity-measuring system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204588601U CN202404111U (en) | 2011-11-18 | 2011-11-18 | DSP-based video velocity-measuring system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202404111U true CN202404111U (en) | 2012-08-29 |
Family
ID=46701751
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011204588601U Expired - Fee Related CN202404111U (en) | 2011-11-18 | 2011-11-18 | DSP-based video velocity-measuring system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202404111U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102879210A (en) * | 2012-10-09 | 2013-01-16 | 吉林大学 | Device and method for testing brake performances based on stereoscopic vision |
| CN103246964A (en) * | 2013-05-28 | 2013-08-14 | 国家电网公司 | Safe overhauling and monitoring method for substation primary equipment |
| CN104102835A (en) * | 2014-07-11 | 2014-10-15 | 大连理工大学 | Throw training score detection method based on real-time video images |
| CN105072445A (en) * | 2015-07-24 | 2015-11-18 | 杭州映墨科技有限公司 | Video moving object detection method based on block truncation coding compression domain |
-
2011
- 2011-11-18 CN CN2011204588601U patent/CN202404111U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102879210A (en) * | 2012-10-09 | 2013-01-16 | 吉林大学 | Device and method for testing brake performances based on stereoscopic vision |
| CN103246964A (en) * | 2013-05-28 | 2013-08-14 | 国家电网公司 | Safe overhauling and monitoring method for substation primary equipment |
| CN103246964B (en) * | 2013-05-28 | 2016-01-06 | 国家电网公司 | Substation primary equipment safety inspection supervision method |
| CN104102835A (en) * | 2014-07-11 | 2014-10-15 | 大连理工大学 | Throw training score detection method based on real-time video images |
| CN104102835B (en) * | 2014-07-11 | 2017-04-12 | 大连理工大学 | Throw training score detection method based on real-time video images |
| CN105072445A (en) * | 2015-07-24 | 2015-11-18 | 杭州映墨科技有限公司 | Video moving object detection method based on block truncation coding compression domain |
| CN105072445B (en) * | 2015-07-24 | 2018-09-07 | 杭州映墨科技有限公司 | A kind of video moving object detection method based on block truncation coding compression domain |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109716108B (en) | Bituminous paving disease detecting system based on two mesh image analysis | |
| CN103927878B (en) | A kind of automatic shooting device for parking offense and automatically grasp shoot method | |
| CN101514993B (en) | Vehicle speed measurement device based on linear array CCD camera | |
| CN102693632B (en) | Monitoring device and monitoring method based on visual image | |
| CN101510356B (en) | Video detection system and data processing device thereof, video detection method | |
| CN111368706A (en) | Data fusion dynamic vehicle detection method based on millimeter wave radar and machine vision | |
| CN101587646A (en) | Method and system of traffic flow detection based on video identification technology | |
| CN202404111U (en) | DSP-based video velocity-measuring system | |
| CN103676829A (en) | An intelligent urban integrated management system based on videos and a method thereof | |
| CN102426785B (en) | Traffic flow information perception method based on contour and local characteristic point and system thereof | |
| CN106448189A (en) | Multilane speed measuring and block port triggering method and device based on microwaves | |
| CN101853576B (en) | Embedded super-speed video detection method based on FPGA (Field Programmable Gate Array) | |
| CN102819951A (en) | Road target detection system, road target detection method and road target detection device | |
| CN107564285A (en) | Vehicle queue length detection method and system based on microwave | |
| CN101550673B (en) | Distributed type road surface breakage image vehicular collecting system | |
| CN205230349U (en) | Traffic speed of a motor vehicle detects and snapshot system based on TOF camera | |
| CN101320048A (en) | Multi-charge coupled device image sensor large visual field vehicle speed measuring device arranged in sector form | |
| CN113503927A (en) | Drainage pipeline detection robot with flight time module and detection method thereof | |
| CN1937000A (en) | Remote monitoring method for city crossroads and vehicle flow identifying detection method | |
| CN113865644B (en) | Drainage facility operation monitoring system in place | |
| CN104867331B (en) | Traffic incidents detection method and device based on microwave | |
| CN102044155B (en) | Vehicle configuration dimension image detection and analysis device based on field programmable gate array (FPGA) | |
| CN201266436Y (en) | Multi-video united detection device for mobile vehicle | |
| CN204557788U (en) | Based on the traffic incidents detection device of microwave | |
| CN104006804A (en) | Method for detecting offset of contact net based on observation benchmark instability compensation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120829 Termination date: 20121118 |