The Design And Implementation Of The Pointer Meter Reading Recognition System In The Substation Inspection Robot

Pointer instrument is widely used in the condition monitoring of power equipment operation,power switch gas pressure and other aspects because of its simple structure design,convenient maintenance,anti-electromagnetic inter-ference and durability.With the rapid judgment of equipment operation fault in substation,the previous manual inspection,meter reading and recording mode has been unable to meet the requirements of substation management and production efficiency,and the technology of automatic identification of indicators and distributed monitoring technology are directly related to the development pro-cess of substation automation and informatization.Among them,the automatic identification technology of instrument indication is the precondition to extract,fuse and mine the operation status parameters of equipment in substation,and to provide reference and guidance for production management.At present,pointer meters mostly adopt the principle based on automatic visual recognition of a machine.The key technologies include the positioning of turning center of dial,the extraction of pointer centerline,the automatic recognition of multi-pointer dial and the adaptive illumination change of dial image.At pr-esent,these technologies have made some progress at home and abroad,but they are not deep and mature enough.In order to promote the development of substation toward automation and informationization,this paper based on the application background of the substation automation transformation sub-project,takes the pointer instrument widely used in substation as the identification object to compare the commonly used image recognition algorithm of instruments,and designed a set of feasible pointer instrument recognition scheme.The main research contents are as follows:First of all,according to the accuracy level and the image acquisition environment of the instrument,the initial image of the target with better quality is selected through the hardware of image acquisition equipment.The digital image processing technology is used to preprocess the initial instrument image of pointer,highlighting dial information through removing the noise interference in the original instrument image by means of median filtering and image enhancement.Graphics are binarized and prioritized in the light of the Law so as to extract exterior information in accordance with morphology.Secondly,the pointer image after noise removal will have a certain angle tilt.The tilted image will affect the later extraction of pointer eigenvalues and the inter-pretation of pointer readings.Therefore,tilt correction must be carried out to make the image meet the recognition requirements.In this paper,a project-ion-based method is proposed to detect the tilt angle of an image.Thirdly,according to the actual needs,an algorithm for extracting the dial is proposed.In almost all existing systems,the pure dial image is used as the starting point of recognition,but the actual background of these images is often more complex.The edge detection algorithm is used to detect the edge of the instrument image first,and then Hough algorithm is used to detect the circle of the circular dial and extract it from the dial.Fourth,adjust and improve pointer feature extraction methods.The types of pointer instruments are diversified,which makes the environment of pointer and dial also have the characteristics of diversity.The automatic recognition system should be able to extract the features correctly when dealing with various situations.This paper uses skeleton extraction instead of edge feature to solve the transplantation problem of recognition system.Fifth,the calculation method of pointer reading is standardized.A new more accurate recognition method based on traditional angle method and distance method is proposed.In addition to ensuring the accuracy of distance method,the parameters of distance method can be converted into angles,and the degree of manual participation can be reduced,so that the accuracy of automatic reading can be improved.Finally,by means of experiments,the accuracy of the method proposed in this paper based on the reading of pointer instrument is verified.It is concluded that the method proposed in this paper can meet the needs of measurement and has corresponding research significance.