高性能乘加单元设计

对高性能乘加单元的设计原理与方法进行了研究,采用改进的Booth算法设计乘法器,提出了一种新的实现这种算法的内部电路逻辑结构。采用这种结构设计MAC单元,大大提高了MAC单元的速度和性能。     

High speed interpolation for micro-line trajectory and adaptive real-time look-ahead scheme in CNC machining

CNC machining plays an important role in mechanical manufacturing.A key issue is to improve the machining feedrate while keeping the machining precision and satisfying the acceleration constraints of the CNC machine.For the consecutive micro-line segments interpolation,the velocities at the junction of two segments are the bottlenecks for the machining efficiency.This paper proposes a multi-period turning method to improve the feedrate at the junctions using the linear acceleration and deceleration mode,whi...     

基于纯追踪曲线跟踪模型的车辆自动导航

介绍具有仿生性的基于纯追踪曲线跟踪模型的曲线跟踪算法。该算法以简化二轮车模型为基础,通过选择合适前视距离计算车辆逼近预定义路径所需摆角达到跟踪效果。通过MATLAB/Simulink仿真,对算法中前视距离和车辆速度两个重要参数对车辆跟踪效果的影响进行了仿真探讨。仿真结果说明该算法容易实现,稳定性高,跟踪预定义路径所需时间较短,跟踪精度较高。     

计算机辅助测试序列优化

为自动获取平均测试费用最少,且能快速实现系统故障检测与隔离的最优测试序列,提出了一种准多步前向搜索算法。该算法结合了一步前向搜索和多步前向搜索的基本特点,并以信息增益为启发策略,获得了计算精度和复杂度的权衡。基于该算法,开发了一个测试序列优化工具,通过对大量实例的计算,证明该工具可以在实用中取得满意结果,且该工具可以用作自动测试设备和便携式维修辅助软件的核心诊断推理机。     

Entropy-based dispatching for automatic guided vehicles

A highly desirable performance of a factory is achieving a laminar flow of parts within the factory. This paper proposes new automatic guided vehicle (AGV) dispatching algorithms with the objective of load balancing among the factory work centres by choosing the dispatch decision, which contributes the most to the laminar flow of the factory. The Kullback–Leibler directed divergence measure is applied to compare a dispatch decision with a balanced factory. Simulation experiments are conducted to study the effectiveness of suggested algorithms.     

Bi-objective dynamic control of batch processor with non-identical jobs in mould manufacturing

The heat-treatment operation in dynamic mould manufacturing often involves non-identical jobs, which allow for simultaneous processing yet with different weights and due dates. Effective production control of this operation is essential to improve the on-time delivery and decrease the manufacturing cost of the mould. This paper considers the dynamic control of a batch processor for dealing with such non-identical jobs. A new look-ahead batching strategy called MLAB (mould: look-ahead batching) has been proposed. In MLAB, the control decisions are made by the joint use of both near-future arrival information of upstream operations and workload level information of downstream operations. MLAB strategy is used to control two kinds of conflicting objectives related to the delivery and utilisation performances and finally achieve trade-off based on compromise programming method. Computational experiments are conducted to verify the effectiveness of the MLAB strategy and show that the results are promising as compared to benchmark control strategies.     

结合look-ahead值排序的自适应分支求解算法

基于新近提出的自适应分支约束求解框架,结合look-ahead值启发式,提出一种新的约束求解算法AdaptBranchLVO。为验证算法效率,在标准测试库上进行了充分对比实验。结果表明,新提出算法在效率上明显优于已有的自适应分支求解算法。     

考虑时变输入时滞及频段约束的车辆主动悬架预瞄控制

针对预瞄控制中存在的输入时滞现象,提出一种时滞相关的有限频域线性变参数控制器设计方法,用于解决存在输入时滞及时变速度的汽车主动悬架预瞄控制问题。在控制器设计中,应用Padé方法将控制方程扩维为含路面预瞄信息的状态空间形式。用有限顶点的多胞形结构处理速度的时变性。以线性不等式的形式给出了控制器设计准则。区别于传统的全频域时滞相关的H∞控制,以车身加速度的有限频域H∞范数为优化性能指标,使其在关心频段内取得最小的能量增益值,同时保证相关的时域约束条件。通过数值算例及试验表明,在存在输入时滞的情况下,该方法能取得比无预瞄控制保守性更小的结果,舒适性得到了显著的提高。     

参数曲线柔性加减速前瞻控制算法

针对参数曲线插补的特点,使用S形加减速和三角函数加减速相结合的柔性加减速方法对参数曲线的插补路径进行前瞻控制。在规划前瞻速度过程中,首先根据加工曲线的曲率变化自适应地将前瞻距离分为曲率上升段和曲率下降段。在对前瞻路径进行S形加减速规划时,遇到路径上曲率频繁变化段,为了减小计算量,采用三角函数加减速的方法对速度进行重新规划。这样,在满足机床加减速要求的同时降低了系统计算负荷。仿真结果和实例表明,该算法能够适应复杂曲线的变化,满足高速高精度插补的要求。     

东江水下钻爆隧道设计施工难点分析

为了规避建设水下钻爆隧道的风险,有必要对已建成水下钻爆隧道的成功经验及施工中遇到的重点、难点问题进行总结。介绍了水下钻爆隧道安全有效埋深应考虑的因素及东江水下钻爆隧道的合理、安全、经济的埋置深度;根据东江穿越工程的地质条件,确定了东江水下隧道的穿越形式;对水下钻爆隧道设计中的综合超前地质预报、防水、监控量测、施工安全风险管理等重要问题作了深入的探讨。通过分析,对设计及施工过程中可能遇到的重点、难点问题及塌方、涌水、涌泥等地质灾害提出了相应的技术措施,可为国内当前在建和待建长输管道工程的水下钻爆隧道的设计与施工提供参考。