Method for detecting position of automobile meter needle based on mechanical angle and scale identification

A technology for automobile instrumentation and mechanical angle, which is applied in the field of position detection of automobile instrumentation pointers, can solve problems such as pointer deformation, inaccurate scale distribution characteristics, and inability to obtain scale sequences, and achieves the effect of clearing deviations and eliminating corner errors.

Active Publication Date: 2014-04-30
HARBIN INST OF TECH
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  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to solve the problem that the silhouette method will cause the pointer to be deformed after the poor operation when detecting the small angle of the pointer, which will cause difficulties in straight line fitting and the dependence of the detection algorithm of the pointer rotation angle based on the scale on the zero scale on the dial High reliability, wh

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  • Method for detecting position of automobile meter needle based on mechanical angle and scale identification
  • Method for detecting position of automobile meter needle based on mechanical angle and scale identification
  • Method for detecting position of automobile meter needle based on mechanical angle and scale identification

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specific Embodiment approach 1

[0031] Specific Embodiment 1: A method for detecting the position of an automobile meter pointer based on mechanical angle and scale recognition in this embodiment is specifically prepared according to the following steps:

[0032] Step 1. Calculate the rotation angle by using the single-frame grayscale image collected by the camera and the template image;

[0033] Step 2: First, normalize the image grayscale on the single-frame grayscale image collected by the camera, then use the Otsu threshold to binarize the normalized single-frame grayscale image, and then perform a corrosion operation on the single-frame binary image;

[0034] Step 3, using the position of the scale of the automobile instrument to calculate the least squares circle and performing polar coordinate transformation on the single-frame binary image after the corrosion operation from the center of the circle;

[0035] Step 4, after the polar coordinate transformation, refine the pointer in the polar coordinate...

specific Embodiment approach 2

[0042] Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that in step 1, the process of calculating the rotation angle by using the single-frame grayscale image collected by the camera and the template image is as follows:

[0043] (1) Select the template image, if the rotation angle of the template image is close to 0, step the template image at plus or minus 1 degree, where plus or minus 1 degree refers to the rotation angle with the center of the template image as the rotation center; where, The template image is collected when the camera environment is stable and the instrument to be tested is placed without deviation;

[0044](2) Match the selected template image with the collected single-frame grayscale image. The center of the template image is the rotation center. When the template image is rotated at 0 degrees, it is matched with the collected single-frame grayscale image to obtain the matching when the template image is rotated...

specific Embodiment approach 3

[0047] Specific embodiment three: the difference between this embodiment and specific embodiment one or two is that the single-frame grayscale image collected by the camera is firstly normalized in step two, and then the normalized image is normalized using the Otsu threshold. The process of binarizing a single-frame grayscale image and then corroding a single-frame binary image is:

[0048] 1) Normalize the grayscale of the single frame grayscale image collected by the camera:

[0049] Let the grayscale range of the image be [m,n], expand it to [0,255], according to the following formula:

[0050] f(x,y) is the original gray level of a certain point, and g(x,y) is the gray level of the point after normalization;

[0051] 2) Use the Otsu threshold to binarize the normalized single-frame grayscale image:

[0052] (1) Calculate the gray histogram of the image, using P i , i=0, 1, 2, ..., 255 represent each component of the histogram, P i is the probability that the i-th gr...

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Abstract

The invention discloses a method for detecting the position of an automobile meter needle based on a mechanical angle and scale identification and relates to a needle position detection method. The method mainly solves the problems that a needle deforms when being detected in a small angle with a traditional method; dependency on the zero scale is high, so that the orderly scale sequence can not be obtained due to inaccuracy of scale distribution features; rotation errors generated when an instrument panel is assembled will not be detected with the traditional method. The method for detecting the position of the automobile meter needle based on the mechanical angle and the scale identification includes the following steps that firstly, the rotation angle of a single-frame gray level image is calculated; secondly, a single-frame binary image is normalized, binarized and then corroded; thirdly, polar coordinate conversion is carried out on the image; fourthly, parameters of a needle linear equation are obtained; fifthly, the mechanical angle of the needle is calculated; sixthly, the scale value pointed by the needle is calculated out; seventhly, the value of a practical unit is obtained. The method for detecting the position of the automobile meter needle based on the mechanical angle and the scale identification is applied to the needle position detection field.

Description

technical field [0001] The invention relates to a method for detecting the position of an automobile instrument pointer. Background technique [0002] In the industry, the detection content of the instrument panel is mainly to detect the rotation angle error of each meter pointer. The accuracy of pointer detection is the key to the quality of the instrument panel, and the detection of the pointer corner is the most difficult. [0003] At present, most of the instrument panel production industries in my country use manual methods to verify and calibrate pointer instruments. The error of quality inspection is large, the efficiency is very low, and the production cost is increased. Using digital image processing technology to realize the automatic detection of the pointer of the automobile instrument can improve the detection efficiency, reduce the detection error and reduce the production cost. [0004] The instrument inspection system will send a signal to the instrument pa...

Claims

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Application Information

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IPC IPC(8): G01D18/00G01B11/26
Inventor 李竹奇高会军于金泳孙光辉肖峰李博伦
Owner HARBIN INST OF TECH
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