To enhance the pitch-roll resistance performance of tri-axle mining dump trucks, this paper proposes a new hydraulically interconnected suspension system that includes the left and right sides interconnection in the front wheels and X-type cross interconnection in the middle and rear wheels (X-HIS). The impedance transfer matrix method is introduced to derive the pressure-flow relationship of X-HIS. Pressure-flow equations are incorporated into the body-wheel equations, and vehicle model considering pitch-roll resistance is established by coupling the mechanical-hydraulic system. Subsequently, transfer function-based frequency response characterization shows that X-HIS obviously suppresses body pitch and roll angle gains compared to the conventional independent suspension (CIS). Finally, slalom tests and impulse experiments are applied to validate pitch-roll resistance performance. The vehicle’s maximum pitch and roll angles are reduced by 17.04

Textile defect detection technology has become a core component of industrial quality control. With the advancement of artificial intelligence technologies, an increasing number of intelligent recognition methods are being actively researched and deployed in the textile defect detection. To further improve detection accuracy and quality, we propose a new lightweight process named WSF-RTDETR with reduced computational resources. Firstly, we integrated WTConv convolution with residual blocks to form a lightweight WTConv-Block module, which could enhance the capability of capturing detailed features of tiny defective targets while reducing computational overhead. Subsequently, a lightweight slimneck-SSFF feature fusion architecture was constructed to enhance the feature fusion performance. In addition, the Focaler-MPDIoU loss function was presented by incorporating dynamic weight adjustment and multi-scale perception mechanism, which could improve the detection accuracy and convergence speed for tiny defective targets. Finally, we conducted experiments on a textile defect dataset to further validate the effectiveness of the WSF-RTDETR model. The results demonstrate that the model improves mean average precision (mAP50) by 4.71% while reducing GFLOPs and the number of parameters by 24.39% and 31.11%, respectively. The improvements in both detection performance and computational efficiency would provide an effective and reliable solution for industrial textile defect detection.

In the textile quality control system, textile defect detection occupies a central position. In order to solve the problems of numerous model parameters, time-consuming computation, limited precision, and accuracy of tiny features of textile defects in the defect detection process, this paper proposes a textile defect detection method based on the YOLO-GCW network model. First, in order to solve the problem of detection accuracy of tiny defective targets, the CBAM (Convolutional Block Attention Module) attention mechanism was incorporated to guide the model to focus more on the spatial localization information of the defects. Meanwhile, the WIoU (Weighted Intersection over Union) loss function was adopted to enhance model training as well as to improve the detection accuracy, which can also provide a more accurate measure of match between the model-predicted bounding box and the real target to improve the detection capability of tiny defect targets. Consequently, in view of the need for performance optimization and lightweight deployment, the Ghost convolution structure was adopted to replace the traditional convolution for compressing the model parameter scale and promoting the detection speed of complex texture features in textiles. Finally, numerous experiments proved the positive performance of the presented model and demonstrated its efficiency and effectiveness in various scenes.

Most existing assembly accuracy analysis methods focus on rigid assemblies or assume assemblies to be rigid bodies, neglecting the influence of assembly deformation in weak rigid components (WRCs) such as thin-walled structures, cantilever structures, etc. As a result, the assembly accuracy analysis becomes inaccurate, and the accuracy of key components cannot be effectively controlled. This may lead to serious issues such as forced assembly, repair, and rework. To address these problems, this study proposes a rigid–flexible coupling-based assembly accuracy analysis method for WRCs. The stiffness matrix and assembly deformation of WRCs are calculated, and by coupling assembly deformation with other assembly deviations, a rigid–flexible coupling assembly accuracy data model is established. This model incorporates multiple deviation sources, including assembly process variations, design tolerances, and assembly deformations. Assembly deviation transfer modeling and accumulation calculation methods for WRCs are investigated, enabling assembly accuracy simulation and statistical analysis. A case study on WRC assembly accuracy analysis is conducted, and the results demonstrate that the proposed method improves the accuracy of assembly analysis for WRCs, verifying its reliability.

Truck suspension is a vital component supporting the weight of the vehicle body and plays an important role in transferring wheel load and isolating external vibration. The uneven load distribution between the middle and rear wheels of a tri-axle heavy truck will directly affect the driving stability and safety of the vehicle. To enhance the truck's wheel load distribution performance and ride comfort, this paper proposes a new coupling suspension system, including an anti-synchronous middle and rear axle hydraulically interconnected suspension (MR-HIS) and the front axle conventional independent suspension (CIS). Considering the load-bearing characteristics of the middle and rear wheels of the tri-axle heavy truck, a five-degree-of-freedom (5-DOF) half-vehicle model of the truck equipped with MR-HIS is constructed. Further, the dynamics equations of the mechanical-hydraulic coupling system are established according to the impedance transfer matrix method and mechanical-hydraulic boundary conditions, and the truck body motion modes are completely decoupled. The modal analysis demonstrates that compared with CIS the proposed MR-HIS system can reduce the body bounce modal stiffness, increase the modal damping ratio, and enhance the dynamic coupling performance of middle and rear wheels. Subsequently, the frequency response analysis is adopted to evaluate the load distribution and vibration isolation performance of the MR-HIS. The comparison analysis results indicate that the proposed MR-HIS system significantly improves the load balance distribution between the middle and rear wheels and suppresses the load transfer to the front wheel, thus the handling stability of the truck is improved. Meanwhile, the body vibration frequency response analysis shows that the MR-HIS can effectively isolate external vibration and improve driving comfort of the tri-axle heavy truck.

The assembly process is one of the most important spots in the process of product production. A reasonable assembly sequence can not only reduce the assembly workload but also reduce the manufacturing cost of products. Therefore, this paper proposes a product assembly sequence planning method based on the semantic process. First of all, a research framework of product assembly sequence planning based on semantic process knowledge was constructed by analyzing the requirement of product assembly sequence planning for assembly process semantic knowledge. Secondly, an assembly semantic process knowledge information model was proposed. Based on this, assembly sequence planning ontology and SWRL (Semantic Web Rule Language) assembly semantic rules were constructed in Protege software. Thirdly, an iterative modification method for inferring the sequence of an atypical sub-assembly group was designed. Finally, taking the assembly sequence planning process of the drive axle of construction machinery as an example, the construction method of the assembly semantic process knowledge information model and the assembly sequence planning decision technology in this thesis were applied to verify the reliability of the information model.

The harsh working environment in the mining area has put strict requirements for the suspension system performance of mining dump trucks. To improve the anti-pitch and anti-roll ability of tri-axle mining dump trucks, a new type of hydraulically interconnected suspension system is proposed, including the left-right wheel interconnection in front axle and X-cross interconnection in mid-rear axle (X-HIS). The parameter sensitivity of X-HIS is analyzed, and the significant parameters are optimized. Specifically, a vehicle mechanical-hydraulic coupling model is established based on impedance matrix transfer method. The objective functions are obtained by combining the road spectral density matrix, and accuracy of the model is verified by the accumulator pressure experiment of the mining dump truck. Subsequently, the Morris method is applied to analyze the sensitivity of suspension parameters to the bounce, pitch, and roll modes vibration. The results indicate that the sensitive parameters are the initial pressure and volume of the front accumulator, the inner diameter of damping hole, the initial pressure of mid-rear accumulator, and the area ratio of upper and lower chamber of cylinder. The Pareto solution set shows that there is no conflict between the anti-pitch and anti-roll capabilities of X-HIS. The optimized X-HIS improves the ride comfort and anti-roll ability of the vehicle and balances the anti-pitch performance.

This paper presents a case-based reasoning (CBR) method in combination with ontology theory to carry out decision making for assembly sequence planning (ASP). Due to the ontology unifying various kinds of assembly sequence-related knowledge from different sources, the CBR approach enables a unified structured representation of previous cases and target cases to achieve integration and sharing of knowledge. Based on the similarity measure of classes and properties in ontology theory, the similarity calculation between target ASP case and previous ASP cases is carried out by considering the connection type, motion-transmission type, and location-support type, and a similarity-based previous cases retrieval algorithm is proposed. The combination of ontology and CBR enables flexible and high-quality assembly sequence decisions under various conditions; the ontology-based rule-based reasoning (RBR) method is also adopted as a supplement to CBR in the assembly sequence construction process. Additionally, a reducer case is used to validate the effectiveness of the proposed method.

Pressbrake bending is a multi-step metal forming process and widely applied in the fields of aerospace, shipbuilding, and offshore industry. However, the bending residual stress that arise from the previous-pass bending step will affect the stress distribution of the next-pass bending step, and finally affect the springback after unloading, which results in the difficulty to guarantee the dimensional accuracy of the forming part. In this study, the residual stresses for multi-pass pressbrake forming and its influence on springback are systematically investigated. First, the analytical model for the residual stress of the bent specimen with initial curvature is deduced based on geometric relationship and elastic–plastic bending theory. Second, the calculation method of rigid body position redefine to simulate the multi-pass bending forming process is developed, and the numerical method is confirmed by comparison with experimental method. The analytical model to predict the residual stress is shown to be in close agreement with results from numerical method, demonstrating the validity of the analytical model. Finally, the impact of residual stress in single-pass and multi-pass bending forming on springback are discussed thoroughly. It is found that, as the number of forming passes increases, the equivalent plastic strain will increase to 9% of three-pass loading from 7.8% of one-pass loading, which explains the reason of increasing the number of bending passes can not only reduce springback, but also reduce the residual effect of bending forming.

油气悬架因其非线性刚度和阻尼特性,在工程车辆上得到广泛应用.两级压力式油气悬架可以降低车辆重载时的刚度,同时悬架结构参数对其性能有着重要的影响.为了合理地选择两级压力式油气悬架的结构参数,以某型矿用 自卸车1/4油气悬架为研究对象,对悬架性能评价指标进行理论分析,在AMESim中搭建了两级压力式油气悬架模型,通过分析得到结构参数变化对油气悬架性能的影响趋势,并采用Morris法分析了结构参数对悬架性能的灵敏度.结果表明:活塞杆外径和缸筒内径为影响两级压力式油气悬架垂直加速度和动行程的敏感因素;动行程与活塞杆外径呈正相关、与缸筒内径呈负相关;适当降低高压蓄能器的初始压力,可提升车辆平顺性.成果为两级压力式油气悬架结构参数的选择提供参考.

针对传统工程机械臂装配过程中存在的装配效率低、装配过程指标和产品特性无法得到全面反映等问题,在装配过程中引入数字孪生理念,研究基于数字孪生的工程机械臂装配过程建模与仿真技术.通过机械臂装配信息的提取处理,构建了数字孪生环境下装配工艺信息库,为机械臂虚拟装配模型构建奠定基础.通过虚拟空间与实体空间的实时数据交互,形成完整的装配数字孪生体空间.以某挖掘机机械臂的装配线为例,说明了基于数字孪生的装配仿真可实时监测装配过程并对其配置优化以提高装配效率,实现有效的闭环反馈机制.

The bill of materials (BOM) runs through all stages of the life cycle of manufacturing products, which is the core of manufacturing enterprises. With increasing complexity of modern manufacturing engineering and widespread using of intelligent manufacturing technology, the BOM data keeps rising and transformation process is increasingly frequent and complicated. In order to improve efficiency of BOM management and ensure the diversity, accuracy and consistency of BOM in the product development, the BOM multi-view integrated management and mapping method for complex products were researched. First, a complex product BOM integrated management framework and the evolution model based on multiple views were established which described the BOM integrated management mechanism and transformation relationship among different BOMs. Subsequently, process of BOM transformation was analyzed, and a BOM transformation model was proposed. Moreover, a rule-based BOM multi-view mapping algorithm was proposed. With the rule definition and mathematical modelling for key components, the complex mapping principle was elaborated. Finally, the BOM multi-view transformation cases and the prototype system were illustrated and discussed, which verified the feasibility and versatility of model and method.

Aiming at the problems of the moving stability of the mobile station of the hydraulic press, the reliability of the mobile station clamping during the workpiece forging process, and the force requirements of the mobile station, an innovative design of the hydraulic press mobile station based on the Theory of Inventive Problem Solving (TRIZ) is proposed. Firstly, the hydraulic press process model is established, and the overall process of the hydraulic press is transformed into a system function analysis model composed of multiple components, in order to determine the root cause of the problem of the hydraulic press under different working conditions and then define the innovative design goals that need to be improved. Then, the function model is pruned, and the function model is improved. The technical scheme is obtained by using the technology conflict matrix and the Su-Field Model. Finally, the obtained scheme is analyzed in combination with the actual technical requirements of the hydraulic machine mobile workbench system. The results show that the proposed scheme can not only meet the working requirements of the hydraulic press but also improve the stress of the support structure, which can provide a new idea for the structural design of the mobile workbench of the hydraulic press.

本文对建立实验人员"四位一体"绩效考核体系进行了研究,从实验工作量、学科工作量、科研工作量和行政管理工作量等方面进行科学合理量化.实践表明,不仅能激励实验教师在实验教学和管理方面的责任感,同时也提高了学科建设和科学研究方面的积极性,对高校一流学科建设起到促进作用.

架廊机在地下综合管廊安装架设中发挥着重要的作用.本文根据长节段、大吨位整体式预制拼装综合管廊安装架设的需求指标,设计研制了TLJ600T架廊机样机,包括起重天车、主梁、前支腿、中支腿、后支腿以及电液系统等,并选择关键部件主梁建立了三维实体模型,通过有限元分析软件AN-SYS Workbench对其在两种不利工况下进行了静力学分析.结果表明,主梁的强度和刚度均满足设计指标要求.同时,架廊机样机的成功研制和应用验证了该机械设备结构设计合理,符合项目需求.

为保证雄安新区预制综合管廊建设项目的施工质量和效率,研制长节段大吨位预制综合管廊施工关键设备.在对长节段大吨位综合管廊预制工艺、运输工艺及架设工艺分析的基础上,研制了综合管廊预制自行走液压模板、大吨位钢筋笼吊具、管廊运输车、廊上运廊车、液压自平衡管廊吊具、大吨位管廊架廊机等关键施工设备.通过现场应用及工效分析,说明研制的关键设备能够有效提高综合管廊整体预制质量和效率,满足了雄安新区综合管廊建设项目的需求,并为我国长节段大吨位综合管廊建设提供了关键设备参考.

矿用自卸车具有载重量大、能够在恶劣路况行驶的特点,油气悬架因其刚度和阻尼的非线性特性能较好适应外载荷激励变化,在大型工程车辆中得到广泛应用.为解决单气室油气悬架在车辆重载时刚度过高的问题,设计了一种新型两级压力式油气悬架,并以某型矿用自卸车1/4油气悬架为研究对象,通过仿真和实验对比分析了单气室油气悬架与两级压力式油气悬架在通过路面障碍物时的系统输出特性.结果表明:通过高度120 mm的路面障碍时,与单气室油气悬架相比,两级压力式油气悬架的油缸峰值压力降低了 12.54％;活塞压缩行程的最大位移增加了 37 mm,这将更有利于保持车身姿态,提高防侧倾能力;车辆振动的加速度峰值降低了 26.10％,功率谱密度峰值降低了 27.52％,车辆行驶平顺性得到明显改善.

Prefabricated utility tunnels play an important role in modern urban infrastructure construction. However, prefabricated utility tunnel segments are heavy, and the hoisting conditions are complicated, resulting in increased requirements in terms of the reliability of the equipment used for the erection and paving of utility tunnels, especially the hydraulic system of tunnel-erecting machines. Therefore, in this study, we performed reliability analysis of the hydraulic system of a tunnel-erecting machine. First, the working principle of the tunnel-erecting machine and its hydraulic system is analyzed, and a Takagi-Sugeno (T-S) dynamic fault tree model is constructed using the T-S dynamic fault tree analysis method, which is further transformed into a Bayesian network (BN) model. Secondly, according to the failure probability of the root node, combined with the BN conditional probability table (CPT), the failure probability of the leaf nodes of the hydraulic system of the tunnel-erecting machine in each time period and task time is forwardly inferred. Then, through the quantitative analysis of the sensitivity parameters in the BN analysis method, the importance of the components in the system can be reflected. Finally, the posterior probability of failure of the root node of the hydraulic system is calculated through the reverse reasoning of the BN analysis method, and the sensitive components of the system are identified. The results show that the proposed method can determine the main factors affecting the hydraulic system of a tunnel-erecting machine and provide reference for the safe operation of such equipment, as well as system maintenance.

为解决长节段大吨位整体式预制拼装综合管廊施工中存在的安装控制难度大、架设施工效率低等问题,依托雄安新区装配式综合管廊项目,提出基于廊上运廊及廊上架廊技术的预制综合管廊安装施工工艺方案,并研制出一套集成450 t轮轨式提廊机、TLC600运廊车、TLJ600架廊机和预应力智能张拉仪的管廊架设安装设备系统.廊上运廊工艺可避免修建运廊便道,减少土方开挖量;廊上架廊工艺可提高架设稳定性,满足管廊节段安装和回转吊装;采用机械设备协同作业可提高架设安装自动化水平.实践表明:该预制综合管廊施工工艺实现了长节段大吨位装配式综合管廊的安全架设,可保证预制管廊节段的吊装稳定性和安装精度,提高大吨位整体式装配综合管廊的建造效率.

烛式油气悬架兼有主销的作用,所以通常具有2°～5°的安装内倾角,内倾角会造成油气缸承受横向力的作用,从而增大缸筒和活塞之间的摩擦力.摩擦力增大会影响油气缸的减振性和车辆乘坐舒适性,严重时会造成油气缸"摩擦锁死"现象,使油气缸失去减振能力.以某矿用自卸车的烛式油气悬架为研究对象,通过理论分析了缸筒和活塞之间摩擦力的影响因素,得出了延长活塞导向长度可以减小缸筒和活塞之间摩擦力的结论.通过装载试验和矿区路面行驶试验对比了导向长度分别为0.10,0.15,0.20 m时,油气缸的减振能力和车辆乘坐舒适性.结果 表明:其他参数不变,当活塞导向长度由0.10m增加至0.20 m时,油气缸的振动传递率由0.65变为0.47,油气缸的减振能力提高了27.7％;整车的总加权加速度均方根值从1.06 m/s2下降到0.72 m/s2,车辆乘坐舒适性明显提高.