The use of testing equipment can effectively improve the testing efficiency, save labor, reduce production costs, thus improving economic benefits. However, many factories and enterprises now buy testing equipment because of inexperienced operators, resulting in some small problems in the production process often affect the testing effect of testing equipment. Today, Rick sorted out some factors affecting the detection effect for you, I hope it will be helpful to you.

1. Hardware selection

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

The selection of hardware for visual inspection is a difficult task, which requires engineers to be very familiar with the hardware itself and hardware suppliers and have enough experience in selection. The environment for machine vision systems running in the lab and systems running in the real world is vastly different.

Visual inspection includes some important components, such as light source, lens, camera, image acquisition card, data transmission, image processing and measurement software, etc. As the performance of each component improves, the capabilities of machine vision systems increase exponentially. The complexity of the system depends on the specific application requirements. The selection of the best component should 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 final environmental conditions of the system. For example, in the industrial field, these environmental conditions include component changes, load shifting, positioning, handling interfaces, vibration, ambient light, temperature, dust, oil, water, electromagnetic radiation, etc. In extremely harsh conditions, it is sometimes necessary to add protective measures to machine vision components. The most obvious example is that some cameras need to be used in relatively clean environments. In general, however, the industrial environment is suitable for the direct use of industrial cameras.

Even in the most stable vision system, the results are often not ideal due to external influences, for example, vibration will lead to blurred and distorted images, variable parts will lead to different images, and too long exposure time will lead to distorted image sharpness of moving objects.

2, the impact of environment

The impact of environment on machine vision hardware is not only destructive to the hardware itself, but also has an impact on the measurement effect. For example, most industrial cameras are capable of operating between -5 degrees and 65 degrees in the environment of temperature change. In the actual environment, too high temperature often brings noise to camera imaging. However, this can be improved by improving the lighting method to improve the signal-to-noise ratio.

In addition, the temperature will affect the performance of the LED light source. As the LED temperature rises, its brightness decreases, which can be compensated by the light source controller. The heat generated by LED itself will also accelerate aging or even scrap directly, so a good thermal design is needed.

Other components also have temperature limits. For example, industrial controllers/embedded PCS generally work in industrial environments, but without a fan, it is likely that the PC will die. In order to ensure the stability of visual imaging, in addition to the selection of good hardware, we should also consider the temperature sensitivity of the object to be measured. For example, metal objects have thermal expansion and cold contraction. Therefore, when measuring such objects, the length and volume will change.

● Vibration

Most industrial cameras are anti-vibration. Robots and track cables can make the camera move without vibration. The locked connector protects the camera from vibration. Durable PC and embedded PC have good stability protection mechanism. Prime lenses are protected from vibration by metal locking screws. The filter protects the lens to some extent.

● Ambient light

Daily filters are designed to avoid ambient light to some extent by changing the information that light enters the sensor. By using a high-intensity modulated light source, reducing the sensor exposure time and reducing the aperture, the impact of ambient light can be minimized. Using cameras with wavelengths such as infrared to make measurements can reduce the effect of visible light.

● Dust, dirt, water

Many cameras can achieve IP65/67 protection rating, ensuring dust and water resistance. Dust, dirt, liquid and steam tend to adhere to the surface of LED or lens, affecting the image. Adjustments can be made by increasing the gain of the camera, image processing of the software, and adjusting the output of the LED.

All kinds of environmental factors can affect imaging, and these effects can be deadly, because the image is an important reference for measurement.