What are the detection effects that affect machine vision inspection equipment?

       Machine vision inspection equipment has the characteristics of high precision, high efficiency, high accuracy, automatic loading and unloading, etc. It not only replaces manual quality inspection, but also improves quality and efficiency. However, many factories and companies usually buy back the testing equipment because the operators have no experience. As a result, some small problems often affect the testing effect of the testing equipment during the production process. Today, Xinxiwang will sort out some factors that affect the detection effect. I hope it will be helpful to everyone.

1. Hardware selection

Stable image feature extraction is the prerequisite for image analysis and image recognition. Ensuring a stable imaging is transmitted to the image processing center can ensure the accuracy of the image processed by the software. Many factors will affect the stability of imaging, such as the surrounding environment, object changes, and the impact of visual hardware.

Selection of visual inspection hardware is a difficult task. It requires engineers to be very familiar with the hardware itself and the hardware supplier, and to have sufficient selection experience. The environments faced by machine vision systems running in the laboratory and systems running in actual work scenarios are very different.

Machine Vision Inspection Equipment Defect Inspection Equipment Screening Machine 

Visual inspection includes some important components, light sources, lenses, cameras, image capture cards, data transmission, image processing and measurement software, etc. As the performance of individual components improves, the capabilities of machine vision systems also increase exponentially. The complexity of the system depends on the specific application requirements. When choosing the best components, you must not only consider whether the performance of the component can meet the requirements (such as resolution, frame rate, measurement algorithm, etc.), but also consider the environmental conditions in which the system will eventually be located. For example, in the industrial field, these environmental conditions include component changes, transfer, positioning, processing interfaces, vibration, ambient light, temperature, dust, oil, water, electromagnetic radiation, etc. Under extremely harsh conditions, it is sometimes necessary to add protective measures to machine vision components. *Typical example, some cameras need to be used in a relatively clean environment. However, usually, the industrial environment can meet the direct use of industrial cameras.

Even the most stable vision system often produces unsatisfactory results due to external influences. For example, vibration can cause image blur and distortion, variable parts can lead to different images, and long exposure times can cause motion. The image sharpness of the object is distorted.

2. Environmental impact

The impact of the environment on machine vision hardware is not only destructive to the hardware itself, but also affects the measurement results. For example, in an environment with changing temperatures, most industrial cameras can work between -5 degrees and 65 degrees. In actual environments, too high temperatures often bring noise to camera imaging. However, this can be improved by improving lighting methods.

In addition, temperature will affect the performance of the LED light source. As the LED temperature increases, its brightness decreases. This can be compensated for the brightness output by the light source controller. The heat generated by the LED itself will also accelerate aging or even directly scrap it, so good thermal design is required.

Other components will also have corresponding temperature limits. For example, industrial controllers/embedded PCs can generally be used in industrial environments, but if there is no fan, the PC will most likely be scrapped. In order to ensure the stability of visual imaging, in addition to selecting good hardware, we must also consider the sensitivity of the object being measured to temperature. For example, metal objects expand and contract with temperature. Therefore, when measuring such objects, the length and The volume will change.

vibration

Most industrial cameras have anti-vibration treatment, and robot and track cables can effectively allow the camera to move without being affected by vibration. Locking connectors protect the camera from vibration. Durability PCs and embedded computers have good stability protection mechanisms. The fixed focus lens uses a metal mount locking screw to ensure that it is not affected by vibration. The filter protects the lens to a certain extent.

ambient light

Daily filters can avoid being affected by ambient light to a certain extent. They can change the information of light entering the sensor. By using a high-brightness modulated light source, reducing sensor exposure time and reducing aperture, the impact of ambient light can be minimized. Using cameras with wavelengths such as infrared to measure can reduce the impact of visible light.

dust, dirt, water

Many cameras can achieve IP65/67 protection level, ensuring dustproof and waterproof. Dust, dirt, liquid, and steam often adhere to the LED or lens surface, affecting the imaging. This can be adjusted by increasing the gain of the camera, image processing of the software, and adjusting the output of the LED.

Various environmental factors will have an impact on imaging, and these effects will be fatal, because the image is an important reference for measurement.