The development of digital intelligent welding tong system is a technological development direction with broad application prospects. The developed digital intelligent welding tong system is a mode breakthrough of the traditional welding tong that is fitted with various intelligent sensors and data collectors on the basis of traditional welding tong, so that they have key big data collection capabilities. Through the development of SCADA system with intelligent welding tong data, welding controller data and workpiece data analysis, to achieve intelligent welding tong condition monitoring, predictive maintenance, solder joint online quality monitoring and trace warning and workpiece quality report push function, the upgrading demand of digital and intelligent transformation of the traditional welding tong is realized on the welding line.

In the era of rapid development of digital transformation, machine vision is widely applied in most of industries. This paper introduced the visual acquisition method and processing method, on this basis it explained the advantages of machine vision compared with traditional artificial vision via workshop demonstration. It is proved that this method fundamentally solves the problem of labor cost and makes the automobile manufacturing higher quality, lower cost and more flexible in the aspects of visual guided parts, visual guided assembly, visual inspection, and visual online measurement.

In order to reduce the cost of the solder joint grinding process and control the grinding quality, this paper studies an automatic grinding tool held by a robot and its control system. The closed-loop control is realized through the force control sensor, the feedback is completed within 60 ms and drive the flexible control unit at the same time. Finally, the precision error of the output grinding force is less than 1 N, so that it can grind the complex surface of the body parts. According to the material characteristics of body parts, appropriate grinding apparatus are selected through experiments to ensure the grinding quality. The grinding process is designed according to the process characteristics of the production line, and finally the automatic grinding technology is applied in the production line.

A fast and flexible switching system based on four models was designed, which could be extended to meet the requirements of random switching welding fixtures online and offline for multiple models, to adapt to the rapid upgrading of automobiles and improve the flexible manufacturing ability of production line. Combined with logistics transfer and automatic access technology of offline jig library, the system solved the problems of flexibility, fast switching, precise positioning, jig storage, made breakthrough in the knotty technical problems of random switching of multiple models, and improved the flexibility and utilization rate of welding production line.

At present, the connection processes for aluminum body in the market include Self-Piercing Riveting(SPR), Flow Drill Screw (FDS) tightening, riveting without nails (CLINCH), etc. Based on the mature application of processes and equipments, this paper explores the interchangeability of different processes to meet the flexible requirements of major OEMs on aluminum connection technologies. The paper mainly introduces the SPR equipments, FDS tightening equipments and CLINCH equipments in the established aluminum connection test facility that can be flexibly switched on the same robot through the rapid on-off of the medium and equipment interface.

To improve the anti-corrosion properties of electroplated parts, a brand new electroplating solution formula system was developed. In this research, the same kinds of electroplating parts were prepared using the same process and different electroplating solution systems to make comparative verification in aspects including coating thickness, potential difference, number of microspores, number of active points, weather resistance and corrosion resistance. The results show that the new microporous nickel system has excellent performance improving the corrosion resistance of electroplating parts, and this article clarifies its anti-corrosion mechanism, which can provide ideas for the development of new electroplating system.

Based on the analysis of the information system requirements of the welding workshop, this paper discussed the application of an intelligent vehicle type management system in the automatic production line of the welding workshop, mainly expounded the network architecture and function outline of the system. The intelligent vehicle type management system is seamlessly integrated with the automatic welding line, realizing the information flow from top to bottom and from bottom to top in the welding workshop, reducing the workload of electrical program debugging for adaptive product production preparation, avoiding the material matching error caused by manual calculation from the root, reducing the automatic line stop rate, improving production efficiency and realizing the digitalization, transparency and intelligence of the workshop.

Based on Explicit simulation environment of ABAQUS, the finite element simulation 3D model of CFRP-Aluminum alloy bolted joint was established, and the corresponding single nail and single shear tensile experimental research were carried out. Combined with the experimental and simulation results, the damage failure modes of the bolted joint under uniaxial tensile loading were obtained. The aluminum alloy failure was based on the Ductile metal failure criterion, the CFRP failure criterion adopted the Hashin criterion modified by Shokrieh, which can represent 7 failure modes of the CFRP in fiber tensile and compression, matrix tensile and compression, delamination tensile and compression, as well as fiber-matrix shear modes, and the stiffness degradation of CFRP was achieved after the initial failure of the CFRP using the stiffness reduction rule. The results showed that the bolted joint’s failure process was divided into 3 phases, the linear elastic phase, the damage initiation phase of the CFRP, and the failure phase of the bolted joint. Comparing the simulation and experimental results, the error between them was 6.3% when considering the strength of the joint, indicating the validity of the finite element simulation model. The analysis of the finite element simulation results revealed that during the failure of the bolted joint, the failure of the CFRP occurred in matrix tensile and compression failure modes as well as delamination compression failure mode, and the damage of the aluminum alloy exhibited significant ductility.

Through the comparative study of different technical routes of aluminum alloy automotive body, this paper proposed the lightweight body solution of “profile frame + cover part” steel-aluminum hybrid heavy truck. Based on the body structure, the material selection, the joining process comparison study and solution formulation were completed, and the CAE software was used to simulate and analyze the modality, stiffness, fatigue and collision performance of the body and all performance indicators meet the product requirements. Compared with the original steel body, the steel and aluminum hybrid heavy duty truck body is 81.5 kg lighter (a decrease of 22.4%), which provides a reference for the subsequent lightweight design and manufacture of heavy duty truck body.

By utilizing the theoretical basis of measurement system analysis and the hypothetical test method, this paper made a detailed experimental study on the evaluation method of the tactile subjective evaluation personnel of automotive interior materials, and gave the judgment standards and result evaluation for the experimental results. Through the experimental study on subjective evaluator evaluation, it is concluded that, when the evaluator is tested by random sampling of 30 samples for 2 evaluations, and when the repeatability is ≥ 70% and the accuracy is ≥ 83%, it can be applied as the standards for judging whether the evaluator is a qualified material tactile subjective evaluator. Thus, the practical problems such as one-sidedness, high cost and long time caused by the judgment of leaders or experts and the subjective evaluation of large amount of samples can be fundamentally solved.

In order to solve the problem of inaccurate positioning or low grasping accuracy of parts grasped by manipulator, this paper proposed a method of grasping irregular parts of manipulator based on 3D vision. This method mainly consisted of 3 algorithm modules: system space calibration, part point cloud location and segmentation, and part pose estimation. The external parameter calibration method of point cloud camera based on 2D image and the part point cloud segmentation method based on image semantic segmentation were proposed. Experiments show that the proposed calibration method achieves a system accuracy error of 1 mm, with high efficiency and strong universality. Compared with the commonly used clustering segmentation, the part point cloud segmentation method has higher accuracy and efficiency. The designed 2-stage part spatial pose calculation method can accurately estimate the 6-DOF pose of the part in space, and the accuracy is improved by about 1.8 times compared with the 1-stage matching method. The proposed manipulator irregular part grasping system based on 3D vision has high precision, strong scalability and wide adaptability.

Based on the mainstream brand robots and the actual project, this paper deeply analyzed the influencing factors of the production pace, the difference of action time between different functions and different models of robots and their impact on the pace, and the load analysis method of robots under static and dynamic load conditions. Through theoretical calculation and actual project verification, it is concluded that in the same range of motion, the motion time of heavy loaded robot is 1.5 times or more than that of conventional loaded robot. According to the analysis, this paper recommended the motion time standards of heavy-duty robot and the method of load redundancy design for robot selection, and briefly described some misunderstandings and countermeasures in the process of robot selection at the conclusion of this paper.