CN103472065A

CN103472065A - Steel plate surface image collection and data transmission method

Info

Publication number: CN103472065A
Application number: CN2013104043942A
Authority: CN
Inventors: 王晓慧; 高冰; 宋宝宇; 王靖震; 王军生; 杨东晓
Original assignee: Angang Steel Co Ltd
Current assignee: Angang Steel Co Ltd
Priority date: 2013-09-06
Filing date: 2013-09-06
Publication date: 2013-12-25

Abstract

The invention provides a steel plate surface image collection and data transmission method. Under the multi-thread control, image data is acquired, pre-processed and sent; an image data acquisition thread, a data pre-processing thread and a data transmission thread are respectively built according to library functions of a network development kit (NDK); an embedded platform is used for processing the acquired image data frame by frame and extracting the image data in each frame of data packet according to data of a charge coupled device (CCD) camera; the total number of data bytes contained in each image and the number of needed data frames are calculated according to the image resolution of a detection system; the image data is stored in a distributed synchronous dynamic random access memory (SDRAM) buffer area frame by frame; an embedded system is used for transmitting the pre-processed image data to an upper computer through the gigabit Ethernet. Functions of acquiring and transmitting images of the CCD camera through the gigabit Ethernet on the embedded platform are realized, the integration level of a self-developed steel plate surface quality detection system can be improved, and the system cost can be greatly reduced.

Description

A kind of surface of steel plate image acquisition and data transmission method

Technical field

The invention belongs to the embedded system industry application, relate in particular to a kind of surface of steel plate image acquisition and data transmission method based on the embedded system Ethernet.

Background technology

Surface Defects in Steel Plate, as one of of paramount importance qualitative factor of band steel, is the main cause caused with steel deep processed product waster, has received increasing concern.The strip surface quality detection system has become and has improved strip quality, promoted the requisite equipment of iron and steel enterprise's product competitiveness.The strip surface quality detection system that current all kinds of production line is used is all the framed structures that adopt ccd image acquisition module+server, as the HTS serial band-steel surface detecting system of German Parsytec company, the cold-strip steel that the iS-2000 automatic checkout system of U.S. Cognex company and the Xu Ke of University of Science & Technology, Beijing etc. develop and Surfaces of Hot Rolled Strip on-line detecting system etc.Said detecting system is all structures that every CCD camera of employing is equipped with a set of image processing server, so system is huge, the cost costliness.

Along with the continuous lifting that improves constantly and image resolution ratio is required of strip speed, the picking rate of view data has also been proposed to new requirement.The DSP flush bonding processor is due to its data processing performance at a high speed, and the advantages such as the operating system of real-time task are widely used in the data acquisition process field.

Summary of the invention

The present invention aims to provide a kind of successful collection and transmission realized the surface of steel plate image, improves the integrated level of detection system, surface of steel plate image acquisition and the data transmission method of cost-saving embedded system Ethernet.

For this reason, the solution that the present invention takes is:

A kind of surface of steel plate image acquisition and data transmission method, adopt the linear CCD camera as the surface of steel plate image collecting device, adopt pattern-recognition and the display platform of server PC as Surface Defects in Steel Plate information, realization is based on NDK(Network Development Kit) the ethernet communication framework carry out collection and the transmission of view data, it is characterized in that, the CCD collected by camera to the surface of steel plate view data transfer to the EMAC interface of dsp processor via switch, denoising through DSP, transfer to the host computer terminal by the EMAC interface again after the pre-service such as splicing, between dsp processor and CCD camera and host computer, all adopt gigabit Ethernet to communicate.Its concrete grammar is:

1, the collection of view data, pre-service and transmission adopt Multi-thread control, utilize the NDK built-in function to set up respectively its corresponding image data acquiring thread, data pre-service thread and data transmission thread.

2, embedded platform is processed frame by frame to the view data collected, and at first, according to CCD camera data transmission Gige-Vision agreement and udp protocol form, extracts view data part in every frame data bag; Then, calculate according to the image resolution ratio of detection system setting data byte sum and the needed data frame number that every width image comprises; Finally view data is deposited in the sdram buffer of allocating in advance frame by frame.

3, embedded platform transfers to host computer by pretreated view data by gigabit Ethernet, total size is set in the SDRAM memory block and is no more than half data buffer area of its capacity, be divided into the M section, be responsible for storage piece image data and image attributes data, determine whether this segment data is transferred to host computer by the status word that judges every section memory block for every section.

Beneficial effect of the present invention is:

The present invention can realize that embedded platform utilizes collection and the transfer function of gigabit Ethernet to the CCD camera image, can improve the integrated level of the plate surface quality detection system of independent research, system cost be can greatly reduce again, and application and the popularization of system are conducive to.

The accompanying drawing explanation

Fig. 1 is the embedded platform hardware configuration;

Fig. 2 is NDK configuration flow figure;

Fig. 3 is single image frame data storage node composition;

Fig. 4 is DDR2 buffer zone view data storage node composition.

Embodiment

As seen from Figure 1, hardware platform of the present invention is mainly formed and is linked in sequence by camera, switch, EMAC interface, DM648 and host computer.

1, the ethernet communication framework of embedded system based on NDK built:

(1) NDK initialization and configuration: at first call NC_SystemOpen () function and come initializtion protocol stack and required memory environment thereof, then call CfgNew () and create the configuration handle, handle calls item value and the label value that CfgAddEntry () adds the configuration entrance successively after creating successfully, Socket buffer size and arp timeout parameter are set, finally call NC_NetStart (Handle, StartEvent, StopEvent, IpaddressEvent) function, ' create the image receiving thread in StartEvent ' function, data pre-service thread and data transmission thread, ' delete created thread in StopEvent ' function.Fig. 2 is shown in by program circuit.

(2) establishment of mission thread: with the abstract API of task of NDK, set up respectively image receiving thread, image pre-service thread and data transmission thread.

hMyTask=TaskCreate(entrypoint,"TaskName",OS_TASKPRINORM,stacksize,arg1,arg2,arg3)；

HMyTask is the TSK mission thread handle of DSP/BIOS, and entrypoint is each mission thread entrance function.

2, the frame by frame processing of embedded system to view data:

(1) according to CCD camera data transmission Gige-Vision agreement, extract the UDP view data packet portion of every frame data, Gige-Vision protocol data form is as follows:

Then the head that the UDP message bag is removed to UDP is the view data part.

(2) image resolution ratio of supposing the detection system setting is N*K, be that pixels across point is N, the capable image of K forms a width detected image altogether, view data length after every frame extracts is the L byte, every width image needs N*K/L frame data bag, piece id information according to every two field picture deposits view data in buffer zone successively, and the picture format of composition as shown in Figure 3.

3, embedded system transfers to host computer to pretreated view data by gigabit Ethernet: the data storage area that at first will be not more than 256M is divided into the M section, be responsible for storage piece image data and image attributes data for every section, as shown in Figure 4, the status word of a M byte is set simultaneously, is used for describing the current state of M width image.Systemic circulation reading state word, be illustrated as completion status when the status word that certain width image is corresponding being detected, and log-on data transformation task thread completes the transformation task of this width view data.

Claims

1. a surface of steel plate image acquisition and data transmission method, adopt the linear CCD camera as the surface of steel plate image collecting device, adopt pattern-recognition and the display platform of server PC as Surface Defects in Steel Plate information, the ethernet communication framework of realization based on NDK carries out collection and the transmission of view data, it is characterized in that, the CCD collected by camera to the surface of steel plate view data transfer to the EMAC interface of dsp processor via switch, denoising through DSP, transfer to the host computer terminal by the EMAC interface again after the pre-service such as splicing, between DSP processor and CCD camera and host computer, all adopt gigabit Ethernet to communicate, its concrete grammar is:

(1), the collection of view data, pre-service and send and adopt Multi-thread control, utilize the NDK built-in function to set up respectively its corresponding image data acquiring thread, data pre-service thread and data transmission thread;

(2), embedded platform processed frame by frame to the view data collected, and at first, according to CCD camera data transmission Gige-Vision agreement and udp protocol form, extracts view data part in every frame data bag; Then, calculate according to the image resolution ratio of detection system setting data byte sum and the needed data frame number that every width image comprises; Finally view data is deposited in the sdram buffer of allocating in advance frame by frame;

(3), embedded platform transfers to host computer by pretreated view data by gigabit Ethernet, total size is set in the SDRAM memory block and is no more than half data buffer area of its capacity, be divided into the M section, be responsible for storage piece image data and image attributes data, determine whether this segment data is transferred to host computer by the status word that judges every section memory block for every section.