Changan Ford Automobile Co., Ltd. (hereinafter referred to as Changan Ford) is a large-scale modern automobile enterprise with cross-regional and multi-brand production and operation capabilities. In recent years, Changan Ford has continuously introduced advanced production technologies, greatly improving fuel economy performance in terms of engines, fuel-saving technologies, and materials. The company's future development focus is on "energy conservation and emission reduction" and "creating more energy-efficient vehicles and more environmentally friendly manufacturing processes."
Transmission assembly is a crucial process in automobile manufacturing, broadly divided into three main steps: First, parts are placed into designated bins; second, the parts in the bins are assembled into smaller components; and third, the smaller components are assembled into a complete transmission. These three steps involve multiple production lines, each of which needs to check for the presence or proper placement of parts after placement.
"The biggest challenge of this application is that if manual inspection is used, firstly, there is an adaptation period for new products, and during this process, the speed and quality of inspection will be problematic; secondly, it will increase labor costs," said an equipment engineer at Changan Ford. "For the production line, mechanical tooling and inspection modifications are very troublesome when facing product updates, and stocking spare parts is also a problem. Once a malfunction occurs, there is no timely response method, so production can only be stopped for repairs, which delays production. In addition, some very subtle differences cannot be detected by either the human eye or the tooling."
Faced with these thorny issues, Changan Ford's equipment engineers needed to find the most suitable solution.
Figure 1. After placing parts into the material box, a camera is needed to detect their presence and whether their placement is correct.
"Ford has long used Cognex's technology and products in its overseas factories and has great trust in the brand. Therefore, Ford's production lines in mainland China also require the use of Cognex products," said an equipment engineer from Changan Ford. "Since we already have a certain understanding of Cognex, we decided to choose Cognex's image-based In-Sight vision system."
Based on the inspection requirements, the basic workflow of the In-Sight vision system is as follows: the material box encounters a stopper on the conveyor belt and stops; the worker or machine puts the part into the material box and presses the button; the PLC sends a signal to the camera, triggering the camera to take a picture; after the camera takes a picture, it runs the program and returns the result to the PLC, which then executes the next instruction; each workstation is equipped with an HMI device, and the camera inspection results and images are displayed on the HMI for easy confirmation and viewing.
The superior PatMax image matching technology, the primary inspection tool of the In-Sight vision system, left a deep impression on the equipment engineers at Changan Ford. "PatMax allows us to easily complete the work, even when adding new products, simply by creating a new image model. Furthermore, a single camera can be set with multiple inspection programs and exposure times, and different inspection programs can be called up via the PLC."
Figure 2 shows that PatMax has both localization and detection functions.
PatMax, the industry gold standard for object and feature localization, provides accurate and repeatable detection under the most challenging conditions. This technique uses a series of boundary curves independent of pixel grids to acquire the geometry of an object, then searches for similar shapes in the image. This technique is not limited by specific grayscale levels. Thus, it can accurately locate objects regardless of their angle, size, and shape, fundamentally improving the capabilities of this method.
The PatMax-based in-sight vision system has many powerful features:
First, the camera supports many communication protocols, making it easy and quick to communicate with the corresponding networks.
Secondly, the camera program primarily uses powerful spreadsheets, enabling multiple photos and inspections when testing complex parts. "In the inspection of some parts, we found that surface grease has a significant impact on the inspection. We solved this problem by adding a method of triggering multiple exposures at once," commented an equipment engineer from Changan Ford. "The camera can store multiple programs, and for situations with many different types of issues, the corresponding program can be retrieved via PLC, which is very convenient and powerful."
Finally, the camera can not only return the results to the PLC, but also send the corresponding data values to the PLC. The image storage function facilitates image tracking in the later stages.
According to reports, this project utilizes the In-Sight 5000 series vision system, which not only meets various needs such as code reading and inspection but also greatly facilitates spare parts work. This series of intelligent cameras is made of robust cast aluminum, equipped with a sealed M12 connector and lens protection, and all are IP67-rated for protection, ensuring extremely reliable inspection performance in any production environment.
The outstanding performance of the In-Sight vision system successfully solved Changan Ford's inspection challenges. "Today, the demand for automobiles is increasing, making both production volume and quality crucial. By adopting the In-Sight vision system, we have solved both of these major problems simultaneously. Now, the factory has significantly increased production volume while maintaining top-notch quality, and also reduced production costs," a Changan Ford equipment engineer concluded. "Whether it's the difficulty of inspection or the speed, Cognex cameras have withstood the test under our rigorous project acceptance.
