Based on the planning practice of the final assembly workshop of a domestic car company, and the final assembly workshop of mainstream OEMs at home and abroad, the intelligent application and practice of the assembly workshop in the six major fields of conveyor line, production management, assembly, customer experience, green manufacturing and emerging technologies are summarized. It provides a reference for planning an idealized intelligent assembly workshop of "intelligent assembly, digital informatization of production management, and intelligent service".
In recent years, Industry 4.0 has swept across the global manufacturing sector. Automobile manufacturing is the vanguard of advanced manufacturing, and intelligent manufacturing in the assembly workshop has made many achievements, but it also needs to be treated rationally. First of all, it is clear that intelligent manufacturing is not the purpose, not the blind pursuit of unmanned factories, black light factories and machine substitution, etc., but to take intelligent manufacturing as the starting point, reduce costs and increase efficiency for the purpose, meet the individual needs of customers, improve the quality of products and added value, and enhance the core competitiveness and profitability of the vehicle factory. Secondly, promoting intelligent manufacturing is a long-term complex system process, involving technology in many fields, do not expect to "work in one battle", should be in a pragmatic and truth-seeking attitude to find out the current situation, benchmarking, top-level system planning, step-by-step implementation, pain points first, continuous optimization.
Intelligent flexible conveyor line
The final assembly conveyor line is divided into a sub-assembly line and a main conveyor line (interior line, chassis line, exterior line, inspection line and final inspection line). The final assembly conveyor line is the main bearing layer of the construction of intelligent, transparent, real-time and flexible final assembly vehicles. The down-linked infrastructure layer and equipment terminal execution layer collect data, and the upward correlation enterprise system layer and management layer for real-time production status management, and its latest intelligent application is mainly reflected in the flexible reduction of the online number of vehicles and capacity matching, the production line clearance and ground clearance pit and the vehicle operation height are intelligently adjustable.
The traditional interior exterior line is a fixed assembly line, and the new interior and exterior line adopts the AGV (Automatic Guided Vehicle) trackless automatic transportation system in the factory in Figure 1 and Figure 2, or the interior and exterior skateboards in Figure 3 are directly arranged on the ground. AGV or ground skateboard vehicle each conveying unit is relatively independent, because there is no need for civil construction, each line body online head and tail in advance to reserve the expansion space of the vehicle and software, according to the production capacity needs, similar to the building block method of the production line station carrier at any time to expand and reduce, or adjust the number of internal and external decoration stations, switch between stations, improve the utilization rate of workstations, also known as flexible retractable production line. Not only large-scale production is guaranteed, but flexibility is guaranteed in order to maximize the use of resources.
Figure 1 Porsche Taycan final assembly line
▲Figure 2 BMW i3 AGV external assembly line
▲Figure 3 GAC New Energy final assembly interior skateboard line
Some factory local production lines have achieved air clearance and ground clearance. The vehicle is directly arranged on the ground, adopts a design without lifting points, cancels the traditional air operation chain, and reducing the ground foundation pit can reduce civil construction, shorten the construction cycle, and save construction costs. As shown in Figure 3, the process hanger is no longer paved in the air at the edge of the line, the air conditioning system is integrated on the column, supplemented by a station tool trolley, and the reduction of the air conveying hanging system makes the workshop more spacious, transparent and the line of sight is unobstructed. Supplemented by a large area of skylights and side windows, to create a bright "sunshine workshop", to create a better working environment, while the height of the plant can be appropriately reduced, to achieve the purpose of reducing costs.
Intelligent adjustable vehicle is mainly used for multi-vehicle mixed line production, automatically adjusting the body assembly height according to the model of the vehicle, the weight of the vehicle, etc. Adapt to different products and different processes, and adjust the operating height at will. As shown in Figure 1, Figure 2 and Figure 3, the operating process height of the interior skateboard line and the external assembly line can be programmed according to the vehicle process flexible servo lifting, and the chassis spreader in Figures 1 and 4 can not only be lifted in the Z direction, but also can be rotated in the range of ° ~ 110 °. Fully considering the principles of ergonomics, the author has made high-level assembly in the most labor-saving and comfortable process, improving the level of safety protection and assembly efficiency, and ensuring the assembly quality of the product.
▲Figure 4 A main engine factory can lift and rotate the spreader
Digital production system
The new digital infrastructure of high-performance WANs and 5G mobile networks provides an important basis for the full digitization of production processes. New digital production system software Through shared interfaces and standardized user boundaries, not only the robots and production equipment within the entire workshop are interconnected with each other, but also the development - design - supplier - production process - customer, the entire value-added chain 360 ° all-round interconnection and interconnection, so that all production processes are absolutely transparent, interconnected, using real-time data to support production and the entire value chain.
Within the factory value chain, the entire assembly shop is fully digitized Paperless, and real-time statistics on production can be seen at a glance via a screen or personal digital assistant, so that you can get the best efficiency control. The use of big data technology to collect and evaluate production data and transmit the results back to the production line, through predictive maintenance to effectively avoid equipment failures, increase business operation time, the system self-test to the deviation and timely notify the responsible employees and quality managers, and then use the historical data previously collected, you can immediately find the cause of the deviation and correct it in time.
At the upper and lower ends of the factory, from development and design to suppliers, production and end-end customers are connected, fast and transparent communication between all units can detect the differences between the supply chain and the consumer side early, thereby shortening the reflection time. For example, in R&D and production, coordination with suppliers allows for the digital and real-time tracking of the logistics status of the parts and materials around the world. Prior to production, the production process can be optimized by visual simulation in virtual reality.
Intelligent assembly
Automobile stamping, welding and painting automation degree is relatively high, due to the relatively complex assembly process, the difference in assembly content between models is large, the degree of flexibility of assembly cooperation is high, the workshop conveying assembly station is relatively small, and the level of automation is relatively low. In recent years, with the development of robot technology and the improvement of the level of platformization of automobile products, more and more automakers have begun to actively deploy automatic assembly and automatic tightening. Using the robot high-precision operation, the assembly quality is stable, and it will not decline due to the passage of time and personnel changes. Improving production efficiency, quality, work safety and flexibility is the way to win the market competition.
It is equipped with 15 kinds of commonly used intelligent automatic assembly or tightening equipment: vehicle identification code engraving, instrumentation, sunroof, front panel, front guard, wind window glue installation, seat, tire, chassis close, chassis tightening, door sealing strip rolling, door water-resistant film coating and battery assembly line (module upper part, housing upper part and housing tightening). The core of "machine substitution" is not unmanned, but less humanization and human-machine cooperation, where to change, how to change, need to be comprehensively evaluated, to avoid excessive automation to damage the flexibility and production efficiency of the factory. First of all, consider the cost recovery cycle and benefits, followed by the use of automation equipment to adjust the efficiency, whether the quality of the product has been improved, and at the same time re-evaluate the impact on the flexibility of the production line.
The sunroof gluing assembly system in Figure 5 is composed of a servo quantitative gluing system, visual guidance, assembly robot and automatic glass conveyor, which can realize automatic gluing, gluing, positioning and assembly. With a 3D visual scanning system, multi-angle real-time monitoring of the pattern and track, the pattern control accuracy of ±0.5 mm, the installation accuracy of ±0.8 mm, compared with the traditional artificial glass installation process greatly improve the quality of assembly, and improve the beat of about 20%, but also save 10% of raw materials. The automatic tire assembly equipment in Figure 6 is composed of a five-axle electric tightening machine, material handling system and visual positioning system, and is interconnected with tire manufacturers, logistics vehicles and tire transmission lines through the information system, and the tires are fully automated from entering the factory to transportation, grasping, positioning and tightening. Grasping and tightening part of the variable distance to improve the degree of flexibility, double shift can save 4 people, about 4 to 5 years to recover the cost of equipment investment.
▲Figure 5 Automatic assembly of the sunroof of an oem factory
▲Figure 6 Tire installation in GAC New Energy assembly workshop
Emerging technologies
The rise of a number of the most promising emerging technologies will bring disruptive changes to automotive smart manufacturing. First, additive manufacturing, Figure 7 is a BMW factory 3D printing sunroof fixture, compared with the traditional fixture weight reduction of 3 Kg, shortening the development cycle of small batches, complex custom chemical assemblies and parts. The second is VR technology for employee training, simulating the actual operation scenarios of different factories at the same point, and allowing employees to more intuitively understand the operation process through virtual screens and improve training efficiency. Third, through personal mobile phones and on-site intelligent terminals, front-line employees accurately obtain production information and communicate instantly. The fourth is the application of intelligent wearables, such as Figure 8 mechanical exoskeleton, to protect the joints, reduce the burden of muscle strain, reduce labor intensity, and improve productivity. Fifth, the application of collaborative robots in the windshield glass primer and tightening station, man-machine collaboration, flexible and easy to use.
▲Figure 7 BMW factory 3D printed sunroof fixture
▲Figure 8 A factory mechanical exoskeleton assists in tightening
conclusion
Intelligent manufacturing covers many fields and the system is extremely complex, and in the gradual evolution, it is far from reaching the "ultimate form". In the process of construction, we should base ourselves on the actual needs of enterprises, explore intelligent manufacturing genes, gain insight into development trends, find gaps according to benchmarks, and learn advanced to make up for shortcomings. With the aim of building an intelligent factory with Chinese characteristics of "equipment automation, personnel efficiency, and management informatization," the assembly workshop has done a good job in top-level planning, multi-departmental coordination, and steady progress step by step. Truly realize the core competitiveness and profitability of automakers through intelligent manufacturing.
Source: AI "Automotive Manufacturing"
Author: Yan Xing, Xu Shidong, Zhang Weiwei, Huang Chikai, Xu Baoqiang
Work unit: Guangzhou Automobile Group Co., Ltd
【Important Statement】This article is an original article and may not be reproduced without permission
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