Best fire Cognex helps BMW ensure long-term custom

Cognex helps BMW ensure long-term customer satisfaction and achieve efficient quality control

customers who are preparing to buy BMW cars in Munich, Germany, have the most critical eyes and require cars to be equipped with the most sophisticated instruments. In recent years, with the increasing demand for head up display (HUD), BMW needs to find a quality control system suitable for HUD. The system should not only ensure a high degree of safety, but also adapt to the speed of the production line

in BMW's production base, the quality control system of HUD is currently installed on the production lines of 5-series and 6-series models, which can be regarded as a model of today's industrial image processing

bmw drivers' new driving experience

hud can bring many conveniences to drivers, so customers' demand for it is increasing day by day. HUD is a device that provides information for drivers. It is developed and produced by Siemens VDO Automotive. The HUD image projector projects the virtual image onto the windshield of the car through a row of optical mirrors, and the imaging position is 2 meters in front of the driver's field of vision. Therefore, the driver can easily see all the important information about the car and navigation. This ensures that the driver who attracts the required steel ball to the electromagnet can obtain information in the best way and minimize the interference to attention

even minor deviation of HUD position caused by troubleshooting will also affect the driver's perception of the surrounding environment, such as road signs, the vertical line of the house and the entrance of the garage

image quality: decisive standard

the quality of the projected image in the car is an important standard to determine whether HUD can be accepted by users. BMW in Munich, Germany, decided to promote HUD as an optional component in the latest 5-series and 6-series models, and attached great importance to it. Therefore, the technology integration Department of BMW research and innovation center needs a special and accurate quality control system. In fact, there was no suitable quality control system based on image processing at that time. This means that BMW will develop a new system in a very short period of time

new solution

the detection method to control HUD image quality has been successfully developed in the laboratory, but there is still a lot of work to be done to really apply it to the actual production process. This research provides important target specifications for the preliminary preparation stage of the quality control system. What further increases the technical difficulty is that the quality control system must coordinate the interaction between the windshield and the HUD image projection of the device in the vehicle. Even if there is a slight defect in this aspect in the equipped car, the car cannot be offline

on the basis of the obtained system design specification parameters, BMW's Technology Integration Department (hereinafter referred to as Ti) contacted many machine vision system suppliers to find a solution based on image processing for application in HUD's quality control system. In the middle of 2002, Ti decided to cooperate with gefasoft Co., Ltd., the system integration partner (PSI) of Cognex. The person in charge of BMW made the decision to cooperate because of the advanced technology embodied in the gefasoft system solution

timing and traceability

the system must first determine the measurement parameters, and then detect quickly and effectively without affecting production. The timing frequency of the production line determines the time available for detection. Of course, the whole detection system of HUD must run within a predetermined time limit and be able to detect a corresponding number of vehicles, so as to prove its economic feasibility. The detection system must be suitable for both left and right-hand driving vehicles. In addition, the detection system of HUD must be fully traceable, and relevant information also needs to be input into the whole information network of the company

accurate and objective

the final data provided by the HUD detection system must be objective and have high accuracy and reliability in quality evaluation and identification. The feasibility study and the planning stage of the project have clearly shown that only PC based high-performance image processing system can be competent for such work. The system needs high-performance hardware equipment, and in order to ensure the maximum reliability and accuracy due to the symmetrical angle design of the machine, the algorithm of visual software must be used

bmw two shift assembly line is not allowed to have any blockage and pause. The acquisition and analysis of 50 test images must be completed in less than two minutes

the whole set of test equipment must be inserted into the vehicle during the production process of the vehicle, and must be in a correct and safe position, and then taken out of the vehicle. This means that in the whole test cycle, the time gap between image acquisition and analysis and calculation is about 30 seconds

Cognex PC based vision system: the highest reliability

the visual quality of the projected virtual image has a wide range of differences, so the detection of the image becomes quite difficult. With the continuous change of production conditions, the image processing process cannot become a factor leading to quality problems. This includes the problem of "image contrast" under changing lighting conditions

the visual tools provided by Cognex visual Library (CVL) have great advantages. They provide an interactive way to access various levels of programs and complex visual software, including more precise detail optimization options. This enables the final solution (tool selection, parameter determination, connection and detail optimization) to achieve higher security in a shorter development time

provide reliable detection under difficult conditions

the visual tools of Cognex are developed according to the most stringent standards, which can ensure the accuracy and safety of operation. The most important details of the target image, such as edge, measurement, angle, curvature and shadow, can be clearly identified one by one. The system will compare the spatial condition of the acquired image and the relationship between these important details with the real-time image. According to the obtained information, the precise position of the target can be determined

therefore, the system can recognize some details with higher stability, accuracy and speed. Through the synchronous detection of the contour and structure of the target image, the influence of the change of lighting conditions and contrast can be eliminated. These properties are proved to be effective in detecting the deformation and distortion of HUD images. The functional safety of visual tools has also reached the standard specified by BMW, that is, more than 99%

meet high standards

the image processing system must meet a series of BMW standards, and the products provided by Cognex have been able to meet these requirements for many years. The really important question is whether the whole system can operate stably and reliably. In a fully parameterized system, no isolated system is allowed. For the technical staff of the factory, the most important thing is how to integrate the image processing system into the factory diagnosis system completely and reliably

ensure the long-term traceability of customer satisfaction

the cooperation between BMW and gefasoft is quite effective. The formation of the final solution largely benefits from gefasoft's flexibility and rapid response in a short time. In 2004, the first HUD detection system was successfully installed and operated. After the success of the whole system, BMW also installed this system on the ordinary automobile production line of the Dingolfing factory. Today, about 12 HUD test systems are running 24 hours in BMW's factory, ensuring the perfect quality of HUD. The first end of the test coupling oil cylinder is connected with the clamping jaw, and the fruit is stored in the database of the central server to ensure complete traceability. The test images are also archived and saved. If the customer requests to view them, even after a few years, the company can prove the quality of the products at the time of shipment

about Cognex

Cognex designs, develops, produces and sells machine vision systems, that is, computers with "vision". Cognex is a global leader in the machine vision industry. Since its establishment in 1981, it has sold more than 300000 sets of machine vision systems, with a cumulative profit of more than $2billion. The modular Vision System Department of Cognex, headquartered in Natick County, Massachusetts, specializes in manufacturing machine vision systems for multiple discrete projects to automate and ensure quality. The surface inspection system Department of Cognex, headquartered in Alameda County, California, specializes in the production of machine vision systems for product surface inspection in continuous mode, such as metal, paper and plastic. In addition to its headquarters in Natick County, Massachusetts, connex has regional offices in North America, Japan, Europe and Southeast Asia. Cognex Europe is headquartered in rueil-. Malmaison, near Paris. Please visit Cognex: