TEO, a manufacturer specializing in R&D and industrial cameras in the United States, is very happy to answer your questions. The calibration of industrial camera is based on the industrial camera model, and the parameters of the industrial camera model are solved through the images of known feature points and world coordinates, and the positional relationship between image points and corresponding spatial points is established. Camera calibration methods can be divided into traditional calibration methods and self-calibration methods. The traditional calibration method is based on the structural information of the calibration object, which can be used for any camera model with high calibration accuracy, but the disadvantage is that it needs a high-precision calibration object. However, the self-calibration method does not depend on the calibration reference, and the method of calibrating the camera only by using the corresponding relationship between the surrounding environment images during the camera movement is called the camera self-calibration method.
The allowable range of camera calibration error is about 0. 1 to 0.5. Calibration depends on special standard equipment to determine the input-output conversion relationship of the sensor. Camera calibration is the process of solving parameters. Calibration refers to re-testing the performance of the sensor in use or after storage. In the process of calibration, if some indicators of the sensor change, it should be corrected.
The industrial camera can choose R-3000 series RegemMarr EVOC gold code, which is compact in structure, simple in deployment, integrated with a megapixel sensor and a high-performance processing chip, and has super computing power, and can stably read bar codes in high-speed motion. Compact body, high cost performance, compact structure, convenient integration, plug and play, quick installation, automatic adjustment and easy setting.
If you have any questions, you can get relevant technical documents, tools, drivers and FAQs online through official website () and enjoy professional official services immediately. You can also directly initiate a dialogue application or submit a message through online communication tools, and our customer service staff will contact you as soon as possible.
Why calibrate the sensor? How to calibrate?
The sensor will drift after a period of use, and it needs to be calibrated with a calibration instrument. (i.e. comparison test to see whether the difference between the actual value and the theoretical value of the sensor is within the acceptable range. )
For example, calibrate a pressure sensor with 0~ 1MPa output of 4~20mA. Input 0pa, 200kpa, 400kpa, 600kpa, 1mpa, and measure the corresponding output currents respectively. Then calculate whether the deviation between the output current value and the theoretical value of 4~20mA is within the range.
If it is out of range, the sensor can no longer be used and needs to be calibrated or replaced. Range, can continue to use.
Extended data:
The sensing element directly senses the measured object and outputs a physical quantity signal having a definite relationship with the measured object; The conversion element converts the physical quantity signal output by the sensitive element into an electrical signal; The conversion circuit is responsible for amplifying and modulating the electrical signal output by the conversion element; Switching elements and switching circuits generally need auxiliary power supply.
The variable frequency power sensor samples the input voltage and current signals through alternating current, and then connects the sampled values with the digital input secondary instrument through transmission systems such as cables and optical fibers. Digital input secondary instrument calculates the sampled values of voltage and current, and can obtain parameters such as voltage effective value, current effective value, fundamental voltage, fundamental current, harmonic voltage, harmonic current, active power, fundamental power and harmonic power.
The temperature and temperature-related parameters are measured by using the characteristic that the resistance value changes with temperature. This sensor is suitable for occasions with high temperature detection accuracy. The widely used thermal resistance materials are platinum, copper, nickel and so on. They have the characteristics of large temperature coefficient of resistance, good linearity, stable performance, wide temperature range and easy processing. Used to measure the temperature in the range of -200℃ ~+500℃.
The traditional camera calibration method needs to use a calibration object with known size. By establishing the corresponding relationship between the points with known coordinates on the calibration object and their image points, the internal and external parameters of the camera model can be obtained by using certain algorithms. According to the different calibration objects, it can be divided into three-dimensional calibration objects and plane calibration objects.
Three-dimensional calibration objects can be calibrated with a single image, and the calibration accuracy is high, but it is difficult to process and maintain high-precision three-dimensional calibration objects. The plane calibration object is simpler than the three-dimensional calibration object, and the accuracy is easy to ensure, but two or more images must be used for calibration.
The traditional camera calibration method always needs a calibration object in the calibration process, and the manufacturing accuracy of the calibration object will affect the calibration result. At the same time, some occasions are not suitable for placing calibration objects, which also limits the application of traditional camera calibration methods.
Baidu encyclopedia-sensor
According to different applications, if the accuracy and distortion rate are high, it is necessary to calibrate.
The calibration of industrial camera is based on the industrial camera model, and the parameters of the industrial camera model are solved through the images of known feature points and world coordinates, and the positional relationship between image points and corresponding spatial points is established. Camera calibration methods can be divided into traditional calibration methods and self-calibration methods. The traditional calibration method is based on the structural information of the calibration object, which can be used for any camera model with high calibration accuracy, but the disadvantage is that it needs a high-precision calibration object. However, the self-calibration method does not depend on the calibration reference, and the method of calibrating the camera only by using the corresponding relationship between the surrounding environment images during the camera movement is called the camera self-calibration method.
The intelligent code reader of RegemMarrRegemMarr EVOC adopted industrial design at the beginning of its design. The IP protection level of TA has reached IP67, which is almost the highest level. Judging from the protection level, this wave of reemmar EVOC is in the atmosphere. Products with protection grade IP67 can be used in harsh industrial environments such as lightning, dust, electromagnetic interference and static electricity, and can run continuously in these harsh environments without being affected.
R-3000 series RegemMarr EVOC gold code can capture and read bar codes quickly and omnidirectionally. Built-in rich IO interface to support complex field requirements. Integrate multiple groups of controllable light sources, realize independent control of light source shunting, and respond to your flexible production requirements. Multi-core parallel processing improves the overall reading speed.
If there is anything unclear, call the 4000-697-797 service hotline anytime and anywhere, and you can get manual services such as product introduction, purchase consultation and after-sales treatment. Any questions you give back will be answered professionally and intimately.
How to Calibrate the Oblique Dressing of Industrial Camera
The calibration methods of industrial cameras include: traditional camera calibration method, active vision camera calibration method and camera self-calibration method.
Traditional camera calibration methods include Tasi two-step method and Zhang calibration method, which can be applied to any camera model with high accuracy. However, the calibration object is needed and the algorithm is complex.
Tsai two-step method is to get the camera parameters linearly first, then consider the distortion factor, get the initial parameter values, and get the final camera parameters through nonlinear optimization. Tsai two-step method is faster, but only radial distortion is considered. This method is not applicable when the camera distortion is serious.
Zhang's calibration method uses a calibration board composed of two-dimensional squares to calibrate, collects pictures of different positions and postures of the calibration board, extracts the pixel coordinates of corners in the pictures, calculates the initial values of internal and external parameters of the camera through homography matrix, estimates the distortion coefficient by nonlinear least square method, and finally optimizes the parameters by maximum likelihood estimation method. This method is simple and accurate, and can meet most occasions.
The active vision calibration method does not need to calibrate the object, and the algorithm is simple and robust. But the cost is high and the equipment is expensive. The camera calibration method based on active vision is to control the camera to do a specific motion through the active system, and use the control platform to control the camera to do a specific motion to shoot multiple groups of images. According to the image information and known displacement changes, the internal and external parameters of the camera are solved. This calibration method requires an accurate control platform, so the cost is high.
Camera self-calibration methods include hierarchical step-by-step calibration method and Kruppa-based self-calibration method. These two methods are flexible and can be calibrated online, but their accuracy and robustness are low.
Hierarchical and step-by-step calibration method is to reconstruct the image sequence by projection method, and then carry out radial calibration and Euclidean calibration on the basis of reconstruction, and obtain the internal and external parameters of the camera through nonlinear optimization algorithm. Because the initial parameters are fuzzy values, the convergence of the optimization algorithm is uncertain.
The self-calibration method based on Kruppa is to establish the constraint equation about the camera's internal parameter matrix through quadratic curve, and calibrate the camera with at least three pairs of images. The length of the image sequence will affect the stability of the calibration algorithm and cannot guarantee the infinite plane in the projective space.
Who can explain the definition and principle of rear intersection and front intersection in surveying and mapping?
Given the coordinates of points A and B, in order to calculate the coordinates of unknown point P, we only need to observe ∠A and ∠ B. This method of determining the plane coordinates of unknown point P is called forward intersection.
Rear intersection refers to setting up a station only at the waiting point, observing two horizontal included angles A and B to three known control points, and then calculating the coordinates of the waiting point, which is called rear intersection.
The principle is to use the back intersection to calculate the external orientation elements, and use the front intersection to calculate the coordinates of the ground points to be determined.
Extended data
The common methods of intersection measurement are forward intersection, side intersection, rear intersection and two-point intersection.
1, the forward intersection method is simple and accurate; When the waiting points are more than the known points, it can effectively save the workload, so it is widely used.
2. Transverse intersection is also widely used. When fewer fixed points are needed, the workload can be saved. However, if the fixed point and the known point are located on the same circle (called dangerous circle), the solution condition will be lost or the point error will increase beyond the allowable limit, so it is generally only used when the graphic condition is good.
3. The intersection of two points is usually only used when individual conditions are difficult. The basic characteristics of the above intersection methods.
4. instead of angle measurement, edge measurement can also be used for front intersection, side intersection, rear intersection and two-point intersection, which is called edge intersection _
Baidu encyclopedia-front intersection
Baidu encyclopedia-rear intersection
Baidu encyclopedia-intersection measurement