A brief discussion on the application performance of industrial camera visual inspection

Throughout the development of the industry, China, as the processing center of the global manufacturing industry, has gradually become one of the most active regions in the development of machine vision in the world, and its applications cover various industries and fields. In industrial sites with extremely complex electromagnetic environments, the stability of machine vision systems has always faced severe challenges. As the core component of machine vision systems, industrial cameras bear the brunt of their application performance stability and reliability.

There are various forms of interference in the power supply at industrial sites. Except for power supply interruptions that are clearly noticeable, most interferences are not easily noticeable. However, it is this imperceptible interference that poses a serious threat to the normal operation of industrial cameras, which will further lead to problems such as false triggering, frame loss, stopped acquisition, and even physical damage to the camera.

Generally speaking, we believe that two aspects should be considered to solve the problem of electromagnetic stability of industrial cameras: First, standardize the installation of industrial sites to create a relatively "comfortable" electromagnetic environment for industrial cameras, such as trying to avoid the imbalance of three-phase power supply loads, and use grounding protection for production line transmission devices; second, special reliability design is needed inside industrial cameras to improve the electromagnetic immunity of the equipment.

The reliability design of industrial cameras generally includes two aspects: hardware and software. In terms of hardware, first of all, transient voltage suppression devices or protection circuits that meet the test level requirements are added to the power ports and signal ports (including data ports and control ports) that connect the camera to external devices in accordance with the electromagnetic immunity requirements of industrial equipment. Secondly, attention is paid to the rational design of grounding, such as the resistance and capacitance of the circuit board and housing. Connection, single-point connection between analog ground and digital ground, etc.; In terms of software, through the software watchdog and bus activity detection mechanism, software errors and bus connection problems caused by strong interference can be effectively detected, and recovery can be completed quickly; the filtering function of digital IO can effectively suppress camera false triggering caused by crosstalk pulses, etc.

The technical difficulty of industrial camera reliability design mainly comes from two aspects: limited hardware design space and verification of design effects. Due to the miniaturization of industrial cameras, the difficulty of electromagnetic design has greatly increased. In addition, in a certain sense, electromagnetic design is an experimental science. A good design is improved through continuous verification and modification. Therefore, it is very important to simulate the electromagnetic environment of industrial sites to conduct early experiments.