基于微分几何的带钢热连轧活套解耦控制

带钢热连轧机活套系统是一个耦合的多输入多输出的非线性系统。针对活套系统的解耦控制问题,提出了基于微分几何的解耦控制方法。微分几何方法利用微分几何中的局部变换来研究系统的基本特性,是处理非线性多变量系统解耦问题的有效数学工具;建立了活套系统的数学模型,利用微分几何方法,通过非线性状态反馈对热连轧活套进行了解耦控制,并针对活套系统实例进行了仿真研究。仿真结果表明,该控制算法具有较好的解耦效果,有效地提高了活套系统的控制效果。     

基于机器学习的非接触式水位计校准算法研究

由于环境等因素影响,用于测量水位的超声波、雷达式等非接触式水位计存在一定的测量误差,更换高精度设备会增加成本,为解决测量误差,提出基于机器学习的水位计校准算法。该算法融合测量误差产生的环境因素,采用迭代 Boosting 学习算法,构建 Adaboost 的单层决策树模型,采用误差辗转递送的强学习算法对测量误差进行校准。算法仿真结果显示,校准结果可以很好地拟合标准设备测量值,校准算法不仅克服更换设备带来的成本,还将传统的仪器校准迁移至后端软件层面,为解决非接触式水位计校准提供新手段。     

双疏纳米涂层改善轴承密封性能技术研究

为了提升滚动轴承密封性能,提出了采用双疏纳米涂层改善滚动轴承密封的方案并进行了系统的试验研究。首次独立研发了可实时光学监测润滑剂端泄的密封试验机。采用水和不同粘度的甘油水溶液作为润滑剂,对比研究了不同转速下双疏纳米涂层对密封性能的改善效果。试验结果表明,在一定的转速范围内,这种双疏纳米涂层都具有一定的防侧泄性能;在速度较低时纳米涂层可以显著提升密封性能,随着速度提高,密封性能下降。     

未知环境下移动机器人遍历路径规划

为提高未知环境下移动机器人遍历路径规划的效率,提出了一种可动态调节启发式规则的滚动路径规划算法.该算法以生物激励神经网络为环境模型,通过在线识别环境信息特征,动态调用静态搜索算法和环绕障碍搜索算法,有效减少了路径的转弯次数.引入虚拟障碍和直接填充算法,解决了u型障碍区域的连续遍历问题.最后通过仿真实验表明了该方法在未知复杂环境下的有效性.     

Position and stiffness analysis of a new asymmetric 2PRR–PPR parallel CNC machine

In this paper, structural stiffness analysis of a new 3-axis asymmetric planar parallel manipulator, a 2 P RR–P P R structural kinematic chain, is investigated. The manipulator is proposed as a tool holder for a 5-axis hybrid computer numerical control (CNC) machine. First, the structure of the robot is introduced and inverse kinematics solution is presented. Secondly, stiffness matrix of the robot is determined using a continuous method based on Castigliano’s theorem and calculation of strain energy of the robot components. This method removes the need for commonly used simplifying assumptions and, therefore, results in good accuracy. For this purpose, force and strain energy for each segment of the robot are analyzed. Finally, to verify the analytical results, commercial FEM software is used to simulate the physical structure of the manipulator. A numerical example is presented which confirms the correctness of the analytical formulations.     

Reduced-order observer-based robust synchronisation control of cold rolling mills with measurement delay

To improve the quality of strip thickness, synchronisation control is investigated for cold rolling mills driven by dual-cylinder electro-hydraulic servo systems. Realising synchronised control in hydraulic automatic gauge control (HAGC) systems of cold rolling mills has challenges with not only the inherent nonlinearities of hydraulic servo systems and uncertainties of load variation but also measurement delay of strip thickness. Since all states are not measurable in practice, output feedback robust synchronisation control problem should be addressed for uncertain nonlinear systems with output delay. Thus, a reduced-order observer-based robust synchronous controller is presented by employing Lyapunov functional stability theory. The controller designed by incorporating the integral of the position synchronisation error of two pistons into state variables successfully guarantees asymptotic convergence to zero of both tracking errors and synchronisation error simultaneously regardless of the nonlinearities and uncertainties as well as the measurement delay. Simulation results in a model obtained from a real cold strip rolling mill demonstrate the effectiveness of the approach.     

Optimization of oval–round pass design using genetic algorithm

The primary purpose of this paper is to propose a computer aided optimal design system to support a generalized oval–round pass design, which is widely used as both intermediate and final passes in the process of rod rolling. This system, which is based on a hybrid model and the genetic algorithm, is developed to improve the efficiency, to reduce the manufacturing errors, as well as to extend the useful life of rolls through uniform wear design. Generalized parametric equations are established for geometrical modeling, graphic plotting of oval–round passes, as well as calculation of the cross section area, contact area and the lengths of contact arcs along the cross section of round groove in the MATLAB programming environment. Moreover, these equations can also realize the parametric transformation between roll profile and mathematical models for the oval–round pass design and optimization. The genetic algorithm is employed for the optimal design of oval–round passes in this paper. The objective functions are formulated for minimization of power consumption in the rolling process, variances between ideal dimensions and design dimensions, as well as variances between the lengths of contact arcs. To reduce the complexity and computational burden of the system, some reliable empirical formulas for the calculations of contact area and contact arc length are applied. Finally, the proposed approach is applied to an oval–round pass design. Through simulation and comparison of results against experimental data acquired from literature, it is found that this system is reliable, effective and easier to use.     

实施船板战略,提高船板生产能力

船板战略是济钢实施从市场信息、获取订单到合同兑现全过程的管理新模式。济钢中板厂实施船板战略,采取对设备薄弱环节进行改进,优化船板生产工艺和控制轧制工艺等措施,提高了船板的产量和质量,船板一次合格率达到99．63％,2006年产量达到43．77万t,其中高强度船板达到5．53万t。     

马钢冷轧乳化液应用与优化

介绍了马钢冷连轧机组乳化液系统的组成及作用,分析了投产初期乳化液在使用过程中出现热划伤产生的机理及轧后板面清洁度低的原因,在实际生产中采取了积极有效的措施,成功解决了热划伤的难题,提高了马钢冷硬卷的板面清洁度。     

宝钢5m厚板轧机宽展数学模型及其应用

在厚板轧制过程中,把握材料的宽展规律,提高宽展预测精度是保证最终钢板宽度满足要求的关键环节.从影响宽展的因素和常用的宽展公式出发,研究宝钢5m厚板轧机PVPC平面形状控制的宽展数学模型及其建模过程,对该模型的特点及实际应用情况做了客观评价.并利用生产中积累的数据,应用数据统计回归方法,对宽展模型的协调因子xt,y1进行优化,从而提高了模型的预测宽展精度,减小了宽度预测偏差.