To address the security vulnerabilities such as user privacy leakage and identity forgery of the traditional CP-ABE algorithm, we propose an improved CP-ABE algorithm in this paper. To achieve higher security, a hybrid signature based on ECDSA and Dilithium is introduced to provide strong non-repudiation of user identities, and a role/attribute-based access control model is designed. With this access control model, only users satisfying the access policy can access ciphertext data and thereby reducing the risk of data leakage. By performing permutation-based encryption on the attributes of the access policy, the enhanced algorithm effectively conceals the plaintext attributes, thereby enhancing the security of the access policy. The enhanced algorithm improves key generation efficiency by extracting the minimum attribute set, enhances encryption efficiency by encrypting the minimum policy satisfying the access policy, and improves decryption efficiency by having the authorization center evaluate access control attribute policies. Performance testing results demonstrate that the improved algorithm is more efficient than the traditional CP-ABE algorithm in key generation and data decryption. Security analysis indicates that compared to traditional CP-ABE algorithms, this enhanced method can effectively prevent user privacy data leakage, identity theft, and forgery attacks.

In the construction of extra high voltage and ultra-high voltage paying-off, the national code requires the unified use of “tension stringing” technology. The site selection of stretch field is an important part of tension stringing. The traditional site selection of the stretch field is mainly determined by the experience of the designer, which has many disadvantages. This paper presents a method of automatic site selection for stretch field. First, two-dimensional and three-dimensional map data are fused in order to obtain the geographic information data on the line; secondly, according to the geographic information data, combined with the line segmentation rules, the segmentation of the entire line is realized to obtain the preliminary site location; finally, according to the factors affecting the establishment of the site, such as the length of the segment, the type of towers, the number of block, buildings, vegetation, road conditions, as well as site area, etc., a mathematical model for optimal site selection of the stretch field is established , with the goal of minimizing the cost of construction, automatic iterative optimization of the model is conducted, to find the optimal site location The proposed method of automatic site selection of the stretch field combines accurate geographic information data, considers various influencing factors, avoids various problems caused by manual experience site selection, improves site selection efficiency and construction safety, and saves construction cost. Experimental results show that this method can get better position of the stretch field.

In tension stringing construction, the site selection of the stretch field is related to the efficiency, safety and cost of the whole wire construction. Surrounding geographic information impacts the site selection extremely seriously. Accurate grasp of the surrounding geographic information along the transmission line is the key to ensure the optimal site selection of the stretch field. Aiming at the geographic image data along the transmission lines collected by the UAV, firstly, the map data is blocked using the image gradient information and the geometric topological relationship in the image; then, the histogram features of the gradient direction are extracted from the blocked data; finally, the support vector machine is used to train the extracted features, and the map data is classified according to the model obtained from the training, and finally the automatic classification and recognition of the geographic information along the transmission lines is obtained. The proposed method can achieve high recognition accuracy by using small samples for training. Through practice, the proposed method can accurately classify map data, thus providing a reliable guarantee for determining the surrounding geographic influences when selecting a site for a stretch field.

The longitudinal beam plays a key role in the load-bearing of commercial vehicles. There are a large number of holes with different diameters on the ventral surface of the longitudinal beam. Therefore, the processing of the ventral surface of the longitudinal beam is of great significance to the production of the longitudinal beam. With the hydraulic press as the main machine, the integral die longitudinal beam ventral punching production line is the main way to process the longitudinal beam ventral hole. Punching efficiency is an important index to measure the quality of production line products. This paper analyzes the punching process of integral die longitudinal beam punching production line. Based on the two aspects of punching method and punching strategy. We propose a double punching processing method and a punching strategy based on modified ant colony algorithm, which reduces the number of punching and the distance of finding holes in the longitudinal beam production line. Through the comparison of the longitudinal beam examples, the punching efficiency of the punching production line of the single-press integral die longitudinal beam can be significantly improved. Finally, the purpose of reducing the time of processing the web of the longitudinal beam in the production line is achieved.

The security protection of mobile Internet of Things (IoT) is becoming increasingly important. In the traditional Single Package Authorization (SPA) protocol, the authenticity of the terminal cannot be proved. This paper propose a Combined Public Key (CPK) and zero-trust based architecture to protect mobile IoT from identity forgery attacks. Specifically, we adopt an enhanced SPA protocol based on CPK, where the CPK matrix merges of multi-dimensional information about users, devices, events and time. In this way, every event is encrypted. Besides, through adopting CPK, the deficiency of subject authenticity proof in SPA can be compensated. Experiments verify the efficiency and validity of the proposed CPK-based SPA authentication method in comparison with the state-of-the-art SPA protocol.

纵梁作为商用车中的重要零件,腹面分布众多不同直径的孔,腹面孔的加工就变得尤为重要,整体模架式纵梁腹面冲孔生产线逐渐成为纵梁腹面冲孔的主要方式,重型机身多频次小位移寻孔是该孔生产线的重要特征,而且稳定性与快速性是寻孔运动控制的关键指标.为实现对寻孔动作的优化,本文基于传动系统建模,对比了 4种加减速控制算法,基于对比控制系统的稳定性与快速性而选择出最优的运动控制算法.最后在所选择的加减速算法规划下,探究纵梁腹面冲孔生产线移动机身的运动规律.

A 1600kN closed double point press is used for the punching process of U-shaped longitudinal beam and more than 10 independent die frames are arranged. Different holes require different punching forces, and multi-station punching will cause eccentric loads, while preload and off-centre load are important factors affecting the precision of the combined frame of closed press. In this paper, a 1600kN press combined frame is designed based on the U-shaped longitudinal beam punching process and the three dimensional model of 1600kN press frame is established by Solidworks. The finite element analysis of preload, symmetrical load and off-centre load was carried out by Ansys Workbench. The deformation of upper beam in Z direction and the relationship between eccentric load factor i and the maximum deformation difference △ h can be obtained, which has important application value to improve the manufacturing accuracy of this type of press.

纵梁主要用于商务车,是支撑车身的重要部件.采用闭式双点多工位压力机完成腹面300多个冲孔的加工,以用于零部件的安装.不同孔径所需冲裁力及冲孔位置不同造成滑块X、Y方向的偏载.本文基于纵梁腹面冲孔工艺设计了双曲轴纵放的主传动系统,并进行了运动学、受力分析,证明了双曲轴纵放可有效增强主传动系统的抗偏载能力;分析了曲柄转角相位差、长度误差及连杆长度误差在精度要求方面对主传动系统抗偏载能力的影响;得到了压力机的许用偏载曲线.

Networked motion control systems (MNCS) are increasingly used in complex motion control. Appropriate network scheduling strategy is very important for MNCS to ensure the stable operation and possess good system performance. When a single form of network scheduling algorithm is used for complex network motion control systems, serious information conflicts may still occur. Based on the discussion of several network scheduling algorithms for multi-sensor MNCS, this paper proposes a hybrid scheduling algorithm of rate monotonic (RM) scheduling algorithm with early deadline first (EDF) scheduling algorithm, which is established according to the importance level of the tasks of the network nodes. Simulation model of NMCS is set up using TrueTime simulation toolbox. The proposed hybrid scheduling strategy is compared with several single network scheduling algorithms by simulation. Simulation results show that the proposed hybrid scheduling strategy can make NMCS achieve better overall performance.

It is impossible to obtain the forming limit curve (FLC) by full zone hydraulic forming test under quasi-static (QS) condition since the liquid will leak from the notches of the specimen once the pressure increases. In this study, a novel method is proposed to investigate the frictionless full zone hydraulic FLC of AA5A06 under high strain rate (HSR) condition based on the impact hydroforming technology (IHF). It is found that the FLC is increased significantly by IHF compared with the quasi-static rigid punch (QS-R) forming and the quasi-static hydraulic (QS-H) forming. Differentiating with the QS-H, the increase amounts of FLC at the biaxial tension zone and the tension-compression zone are notably different for IHF. Additionally, the theoretical calculations of FLC is conducted by using M-K model combining with Hill48 anisotropic yield criterion under QS and HSR conditions. The results calculated by the M-K model reasonably agree with the ones obtained from experimentation under QS and HSR condition, and a higher initial thickness ratio is assigned for HSR considering the neck postponing effect of inertia.

Multi-motor synchronous networked control system (NCS) is widely used in industrial enterprises. In this paper, an improved fuzzy active disturbance rejection control (ADRC) strategy is proposed to reduce the adverse effect of network random delay on multi-motor synchronous control system and improve the synchronous performance of control system. Considering time-varying delay which including long delay and short-time delay, the mathematical model of NCS is established. The improvement of ADRC includes two aspects. First, according to the mathematical model of the control system, the first-order ADRC is adopted to the NCS and tracking differentiator is added to this kind of ADRC to soften the starting process. Secondly, the fuzzy control algorithm is applied to the ADRC to realize real-time tuning of ADRC parameters. One of inputs of fuzzy controller is the network delay. Finally, the simulation model of the three-motor ring coupled synchronous networked control system is set up using Truetime toolbox. The simulation results show that the fuzzy ADRC strategy can obviously improve the tracking performance and synchronization performance of each motor, which proves the feasibility and superiority of the proposed method.

Electromagnetic blank holder is an advanced manufacturing technology. Fuzzy control is used for electromagnetic blank holder control system in this paper. Firstly, the designed device of electromagnetic blank holder is introduced. The force of electromagnetic blank holder is analyzed and its formulas are deduced. The structure of force-current double closed loop control system is adopted. Strategy of fuzzy control of electromagnetic blank holder force is proposed. Design of fuzzy-PID controller is given. Finally, simulation models of electromagnetic blank holder fuzzy control system are established using Matlab/Simulink, Simplorer and Maxwell. By co-simulation, the results show that control system can get good dynamic and static performance using fuzzy-PID algorithm. The research results of this paper can promote the development of drawing technology of high precision metal sheet cylinder.

Electromagnetic blank holder (EBH) is a novel technology of deep drawing for sheet metal. The electromagnetic control of variable blank holder force (BHF) is studied in this paper. First, mathematical model of deep drawing process of cylindrical cup is established. The mathematical relationship between flange radius and deep drawing height in deep drawing process of cylindrical cup is analyzed. The reasonable range of BHF is calculated theoretically. Then, principle of EBH device is introduced, and its simulation model is built. The EBH control system is designed. The co-simulation method are used for verify the feasibility of system. Finally, simulation results of EBH control system are analyzed which include variable blank holder force, distribution of magnetic field, and electromagnetic force. The simulation results show that the distribution of magnetic field and electromagnetic force can meet the requirements of BHF distribution. The performance of the EBH control system is also good. The research results have a good role in promoting the development of electromagnetic blank holder control technology.

In order to make electric vehicle asynchronous motor obtain good speed regulation performance, the SVPWM vector control method of electric vehicle asynchronous motor is studied in this paper. Aiming at the shortcomings of PI controller in speed loop and current loop of SVPWM vector control, a method of using LADRC (Linear Active Disturbance Rejection Control) instead of PI control is proposed. Using the mathematical characteristics of the ADRC and the mathematical model of the asynchronous motor, the controllers based on simplified LADRC is designed for speed loop and current loop. And the fuzzy control is added into LADRC of speed loop to realize the self-adjustment of the LADRC parameter, and the control accuracy of the electric vehicle asynchronous motor speed is further improved. The simulation results show that compared with the traditional PI controlled SVPWM vector control, the improved SVPWM vector control with LADRC and fuzzy control makes the electric vehicle asynchronous motor has better robustness and stability.

Aiming at the problem that the synchronous control performance of multiple motors in a complex industrial production process control system is easily affected by motor parameters and load disturbances. The traditional speed compensator in the adjacent cross-coupling structure of multiple motors is reasonably improved. In view of the effect of motor parameters on synchronization performance, by adding a synchronization coefficient related to rotational inertia to the speed compensator. The integrity of the system is increased, and the effect of different motor parameters on the system synchronization performance is suppressed. Aiming at the influence of internal and external disturbance factors on the synchronization performance, a method of replacing the fixed compensation gain in the speed compensator with a fuzzy PID controller is proposed and designed. The anti-interference of the system is improved, and the influence of internal and external interference on the synchronization performance is suppressed. According to the simulation results, the difference from the traditional synchronization error speed compensator is that the improved synchronization error speed compensator effectively reduces the influence of motor parameters and interference on the system synchronization performance. The synchronization error among motors of the system is decreased, and synchronization performance of the system is improved.

使用Minitab软件中的图形化汇总、时间序列图、相关分析、回归分析等工具分析影响水泥质量的关键因素,为实际生产提供优化调整方向.结果 表明Minitab软件在质量改进方面发挥着重要作用.

建立水溶性铬(Ⅵ)来源确定试验模型,定量分析水泥、熟料中水溶性铬(Ⅵ)来源.熟料模型使用分析纯试剂配制原材料的替换材料,将原材料和替换材料分别配制生料,并分别在实验室和工厂实际生产条件下粉磨生料、煅烧熟料.水泥模型使用CaSO4·2H2O(分析纯)作为石膏替代材料,通过调整配比和粉磨方式配制水泥样品.最终检测各试验方案制备熟料、水泥的水溶性铬(Ⅵ)含量,设计运算公式定量计算熟料中原材料、生料制备过程、熟料煅烧过程中水溶性铬(Ⅵ)带入率,水泥每种原材料中水溶性铬(Ⅵ)具体含量以及粉磨过程中带入的水溶性铬(Ⅵ)含量.以ZQ公司和SF公司模型应用案例验证模型效果,结果表明运用水溶性铬(Ⅵ)来源确定试验模型可快速定量分析水溶性铬(Ⅵ)具体来源,为下一步采取控制措施提供数据基础.

The integrated control strategies of tension control are proposed aiming at dual motors structure of winding tension control system. These include control strategy of start and stop based on threshold switching, closed-loop constant speed control for winding side, and closed-loop tension control for unwinding side. And fuzzy integral separation PID control algorithm is used for tension controller. Design of hardware and software of PLC tension control system are given. Design of communication of host computer with PLC, design of monitoring interface, and implementation of fuzzy integral separation PID algorithm using configuration software are given for host computer. The control technology proposed in this paper and design method of winding tension monitoring system can provide reference and help for intelligent monitoring of relevant tension control system.

The electromagnetic blank holder is an advanced technology for sheet metal drawing using electromagnetic force. This paper introduces the electromagnetic blank holder and its working principle. The calculations of theoretical electromagnetic force, excitation current and maximum coil turns of electromagnetic blank holder system are given. The simulation model of the electromagnetic blank holder system is established using Maxwell software. The static magnetic field simulation of the electromagnetic blank holder is carried out according to the varied size of the plate and varied exciting current of the coil. The magnetic field distribution of the blank holder and magnetic ring is shown. The magnitude values of the electromagnetic force exerted on plate, blank holder and magnetic ring is given. The research results of this paper have important theoretical help for realizing the electromagnetic blank holder of sheet metal drawing in production practice.

Electromagnetic blank holder is an advanced control technology in deep drawing process. In this paper, the technology of electromagnetic blank holder control system is studied. Firstly, the mechanical model of electromagnetic blank holder control system is established. The simulation model of electromagnetic blank holder device is established using Maxwell software. The distribution of magnetic field and electromagnetic force are analyzed. Secondly, Matlab/Simulink software and Maxwell software are linked using Simplorer software. The co-simulation of the electromagnetic blank holder control system is realized for power supply, blank holder device and control system. Finally, the response curves of excitation current and electromagnetic force of electromagnetic blank holder control system are obtained by the co-simulation. The results show that the control system has a good performance of dynamic and steady. The blank holder force can be precisely controlled after researching the electromagnetic blank holder control system. It improves the wrinkling and cracking defects of cylindrical parts in the forming process. It can promote the development of deep drawing technology.