Until recently , the design quality control systems engineers also had several test options to choose , without a fully satisfactory. These options include the expensive single-purpose vision system , multi- function optical sensor array is low , as well as fatigue and lack of concentration vulnerable people affected eye test. Today, however, the most advanced vision sensors are the traditional methods of optimum performance with unprecedented speed , accuracy, size and cost advantages of the combination .
This article will compare various sensing option features, and demonstrate why visual sensing for industrial sensor market in the fastest growing area .
The basic principles of visual sensing
Photoelectric sensor includes an optical sensor element , and the visual sensor has image capturing from an entire light thousands of pixels. Clarity and detail of the image resolution is usually measured by the number of pixels . Banner Engineering Corporation to provide part of the vision sensor can capture 1.3 million pixels. Therefore, regardless of a few meters from the target , or a few centimeters away , the sensor can "see" a very delicate image of the target .
In the captured image , the visual sensor to the reference image stored in memory is compared to an analysis . For example, if the visual sensor is set correctly identify eight bolts are inserted parts of the machine , the sensor that should be rejected only seven components bolt , bolt, or the misalignment of the components. In addition, both parts of the machine in which position the field of view , regardless of whether the component is in the range of 360 ° rotation , the visual sensor can make a judgment .
Advantage of the visual sensor
In the alternative tests available , that the visual system , photoelectric sensors, manual inspection , and visual sensors, vision sensors are usually because of accuracy, ease of use, rich functionality and a reasonable cost to be the best choice.
With increasingly fierce competition in the industry , the profit margin becomes smaller , the manufacturer can not afford due to defective products caused by the high rejection rate . Therefore, prior to generating the high cost problem is detected , manufacturers are moving into the entire manufacturing process inspection work .
¡ô vision systems and vision sensors Comparison
Complex visual system is a mature technology, perform detailed automatic test. However, the complexity and high cost hinders its application in many industries , and its price is usually from 5000 to 50,000 U.S. dollars or more. These complex vision systems require one or more cameras , custom software and a computer. They often need to hire outside consultants to visual design, integration and installation of the system .
Moreover, given the special nature of such systems , they can not be easily converted to use it . These complex systems often require ongoing professional support.
Although the demand for complex visual system still exists, but cheaper and easier to use vision sensors launched, some industrial applications provide better value for money solutions. In addition, because of the visual sensor is smaller, easier to use , more frequent manufacturers in the inspection and verification applications using visual solutions. Vision sensors in factory automation to improve the quality and production efficiency improvements contributed.
¡ô photoelectric sensors and visual sensors Comparison
Photoelectric sensors, machine vision sensor gives designers greater flexibility. Previously required the application of a plurality of photoelectric sensors , vision sensors can now be used to test a number of features . Visual sensor can test a much larger area , and to achieve a greater flexibility in target position and orientation . This allows the visual sensor in some original photoelectric sensor can be resolved only by the application of widely welcomed . Traditionally, these applications also require expensive accessories , and to ensure that the target object is always in the same position and posture of precise motion control .
In addition, because the cost of a basic visual sensor equivalent to only a few parts of the photoelectric sensor with more expensive , so the price is no longer a problem .
Visual sensor switch for the application provides unparalleled flexibility. For example, the production process of switching ( from one single switch mounted yogurt ice cream bucket ) may only need a few seconds , and the remote control is completed. Additional test conditions can be easily added to the application .
¡ô manual inspection and visual sensors Comparison
No matter what advances in factory automation , and many tests are still done with the naked eye . However, in most applications, a number of advantages vision sensor can and non- manual inspection process . Vision sensor can work at much higher speeds ; at a much lower cost perform repeated many times , the same test.
Ever-expanding range of applications
Vision Sensor low cost and ease of use has attracted machine designers and process engineers to integrate it into all kinds of once dependent on manual , multiple photoelectric sensors , or not testing applications . Vision sensors for industrial applications including test, measurement , measurement, orientation, defect detection and sorting . Here are just a few application examples :
¡ô In the car assembly plant , inspection by robots applied to the door frame , the plastic beads are continuous , has the correct width.
¡ô In the bottling plant , the checksum is correct sealing cap , filling level is correct and that no objects have fallen into the bottle before capping
¡ô the packaging production line to ensure the correct location correct packaging label pasted
¡ô In pharmaceutical packaging production line , testing aspirin tablets blister packaging is damaged or missing pills.
¡ô in the metal stamping company , more than 150 per minute speed test stamping parts , more than 13 times faster than manual inspection .
Conclusion : For the visual sensor , this is an exciting time . Ever need a lot of technical expertise , has now become the economic, easy to use. Using the technology for future product development will continue this trend . The challenge now is how to realize the vision sensor in various industries all manufacturing areas of potential , including quality control, measurement and inspection processes.
Improve the efficiency of machine vision quality control
For factory automation and process automation , machine vision is to realize the true meaning of the foundation and an important automatic quality control means. The following is a domestic machine vision market Omron some of the views .
Machine vision , by definition is to use the machine's automation methods to achieve human-like visual ( eye + + visual nerve cells in the optic nerve ) function. For factory automation and process automation , machine vision is to realize the true meaning of the foundation and an important automatic quality control means.
If the sentence with the most simple form of machine vision systems , that is, by the lens, camera and controller consisting of machine vision to replace the manual , according to the object under certain circumstances to get the picture for size , defect , type, matching , text, etc. measurement and determination of various parameters . Helping customers increase productivity, reduce labor uncertainty in this field of automation of product quality.
For machine vision the whole industry chain , the current domestic situation is somewhat special. The supplier side, because the vast majority of foreign manufacturers, the existence of a domestic market, the domestic culture to understand the problem . Everyone has seen the rapid development of the domestic economy , but may contributing factor to this development and foreign situation is different, which is why they can not fully understand a short time . I believe the current situation of domestic sales of hope from most vendors still some distance , even if, like OMRON way to enter the Chinese market more than two decades , in recent years the rapid growth in machine vision , but still far from the current market sales and not far compared to Japan .
For users this side , the biggest problem lies in the lack of understanding of machine vision , of course, there are special cases of domestic reasons , is that the domestic labor costs and machine vision comparison of the initial investment . Or for a new product or solution to the problem do not understand , or is this new method and the traditional artificial contrast is less clear. This requires suppliers to do more to promote .
For users and suppliers as a bridge between - integrators , is also a lack of understanding on machine vision , do not know in addition to mechanical , other than ordinary sensor there is a way through the screen / image do some judgments. Domestic system integrators are also very scarce , while domestic manufacturers of homemade equipment ratio is too low , this is a short period of time can not be resolved .
Machine Vision initial investment with lower labor costs in the domestic context is undoubtedly ready to buy every person needs to consider the issue , which also gave the machine vision system put forward higher requirements, regardless of the price or performance. Based on the above understanding, the industry suggested that in this stage of development of new products , the early market development , customer training, system integrators or cultivation is very important. So we spent a lot of time training in the basics of machine vision , hoping to do the first step to let more people know the machine vision, know its basic principles .
Machine vision for the future is very optimistic, but also confident . I believe in constantly improve their premise, as the domestic increased automation , the whole society to improve product quality requirements , the requirements of the manufacturing sector to improve production efficiency , machine vision this new product , the new concept will be popular.
Like now automated power had gone through these stages , as in the larger market will also have greater achievements. So OMRON believes machine vision of the future is bright, the road is long . As to the exact time , it may take five years , may also be as long as three years or less , because the domestic development once started , the speed is amazing .
Afterword : The current China 's food and packaging machinery, a prominent issue is the new product development cycle is long , imitating many fewer new ideas , not only with the level of knowledge about the designer , and also related to the development of related industries .
Advanced international practice is to form various machine elements stored in a computer database , and then drawing digitized into the computer, the computer automatically synthesize three-dimensional model , and then in the past there had been a production line fault input computer, the computer can demonstrate actual working state , according to the user needs to be modified. Computer-synthesized fast, quick and easy modification work , if the user can not reach certain requirements , the computer will tell you that in order to avoid future disputes. This is completed by computer simulation technology , greatly reducing the packaging machinery ( production line ) of the design cycle , customer satisfaction is also greatly improved .
Of course, this simulation technology also reminded packaging machinery manufacturing in accordance with the functional parts of the first modular , each component has a unified interface between the modules can be freely combined . This change of packaging machinery single and small batch production of the various modules mass production to reduce production costs. But if not a single machine production line , modular combinations can also shorten the design and manufacturing cycle time , reduce production costs. The modular and can make non-standard parts toward standardization, allowing users quick and easy troubleshooting , it reduces the user's operating costs .