控制理论

The basic approach of protecting people from being hurt or killed in an accident is to improve crashworthiness of vehicles. This paper starts with discussing theories and methods for vehicle passive safety design, which included experiential methods, analytic methods, multi-body dynamics methods, crash test methods and the finite element method. Emphasis will be paid to the basic FEM theories and algorithms of impact problems. Topics discussed include the governing equation, element discretization, hourglass control, time integration, material model, shell element algorithms and contact-impact algorithms. For more reliable simulation results, this paper then conducts study on how to accurately get material model parameters by combining the FEM method with experimental method, and develops relevant material test machine and parameter calculating software. Based on that, basic typical impact simulation and test validation study are conducted. On the basis of the above work, the paper studies the thin-shell structures'crashworthiness, which was affected by the following factors: spot-weld features, shell thickness, cross-section and pre-deformation. As to vehicle parts'crashworthiness, the paper conducts simulation study of designing energy-absorbing steering system and adaptive airbag system. A practical energy-absorbing steering wheel is designed as an example. In further depth research, the paper suggests several inverse quantificational methods for vehicle crashworthiness design based on the ideal crash characteristics. The above theories and methods are applied with good results through several practical vehicles' crashworthiness design and improvement.

文中对汽车碰撞安全性的设计理论和方法进行了归类和总结，其中包括经验法、解析法、多刚体动力学法、试验法以及有限元方法等；重点介绍了碰撞有限元法的基本理论和有关算法，涉及到有限元求解控制方程、单元离散、沙漏模态控制、时间积分、材料模型和应力修正、薄壳单元算法以及接触碰撞界面算法等，探讨了有限元计算中的材料模型参数获取技术，开发了相应的材料试验装置及材料模型参数反求软件，在此基础上进行了基本的碰撞仿真算例和试验对比研究；文中通过应用有限元方法研究了薄壁构件的碰撞吸能特性，指出了设计薄壁吸能构件时需要考虑的几个主要影响因素，即焊点、壁厚、横截面和预变形等；在关于车辆部件的碰撞安全性能设计中进行了吸能转向机构和自适应安全气囊的仿真研究，提出了吸能转向机构和自适应安全气囊的仿真研究方法；文中最后探讨了整车碰撞性能的设计与改进方法，提出了以理想碰撞特性为目标，采用分段加速度或者根据碰撞时间进行设计的反推设计法、部件吸能仿真优化设计法等量化设计方法，并通过综合应用文中所讨论的相关技术进行了整车碰撞性能的设计与改进实例研究，所选定的车型是大众化的普通轿车和碰撞安全性基础较差的微型面包车，研究结果表明，本文所提出的设计与改进方法是适用而有效的，具有重要的工程实用意义和价值。

The static performance, steady gain and frequency responses of the control system are very similar to those of 4WS The direct yaw moment control is integrated with the front steering angle control using pole assignment Simulation results show that the integrated system can present an ideal yaw rate response with a small side slip angle at the center of gravity.

通过静态特性、输入前馈稳态增益、频率特性和时域响应仿真比较，显示该控制与四轮转向控制的特性十分相似。从理论上而言，横摆力矩控制可以取代四轮转向系统。提出并建立了极点配置法设计的前轮转角控制和横摆力矩控制的集成模型。

This dissertation deeply studied the theory of CMAC neural networks from learning convergence, generalization ability and the improving of the network model and algorithm, and studied the applications of CMAC neural networks in tank barbette control system combining the national defense research project"Control Algorithm Study of Tank Barbette System". These works are meaningful to enrich the architecture of CMAC theory and to improve the performance of tank gun control system.

本文着重从学习算法的收敛性、网络的泛化能力以及对算法和模型的改进等几个方面深入研究了CMAC神经网络理论，并结合国防95预研项目"坦克炮塔系统控制算法研究"对CMAC神经网络在坦克炮塔控制系统中的应用进行了研究，这些工作对于丰富CMAC神经网络的理论体系，提高坦克炮控系统的性能具有重要的意义。

Because of that, the theory foundment of classification, analysis and designing about controll block is set up.

提出、分析和全面阐述了机械控制模块的共同理论体系和分析方法基础，从而为控制模块的分类、分析、设计等提供了理论基础。

A compound control scheme combining detaching Proportion and Integral control with Model Reference Adaptive Control based on Liapunov stability theory was formulated,which is used on the plant of direct driving electric-servo-actuator.

以直接力驱动电动舵机为被控对象，提出了一种分离比例-积分控制与基于李雅普诺夫稳定性理论的模型参考自适应控制相结合的复合控制方案，该方案充分结合了分离PI控制动态性能好和自适应控制抗干扰能力强、鲁棒性好等优点。

A compound control scheme combining detaching Proportion and Integral control with Model Reference Adaptive Control based on Liapunov stability theory was formulated, which is used on the plant of direct driving electric-servo-actuator. This scheme combined the good property of each algorithm, such as good dynamic property of the PT and strong anti-disturbance ability and good robustness of MARC.

以直接力驱动电动舵机为被控对象，提出了一种分离比例－积分控制与基于李稚普诺夫稳定性理论的模型参考自适应控制相结合的复合控制方案，该方案充分结合了分离PI控制动态性能好和自适应控制抗干扰能力强、鲁棒性好等优点。

According to the characters of debris flow and risk controlling condition in mountain towns, The concentric circle theory of geography is introduced in this paper, The concentric circle model for debris risk control in mountain towns is discussed and the effect of "concentric circle model" in hazard risk control is analyzed.

针对山区城镇泥石流危害特征及风险控制现状，引入地理学中的同心圆理论，探讨了山区城镇泥石流风险控制的"同心圆模式"，分析了"同心圆模式"中各风险控制层对灾害风险的控制机制及效应，提出城镇泥石流风险控制应遵循多层防范、逐级降低的思路，研究可为山区城镇的减灾管理提供合理的参考。

Vector Control is based on motor unification principle, energy conversion and vector coordinate transformation theory.

矢量控制作为一种先进的控制策略，是在电机统一理论、机电能量转换和坐标变换理论的基础上发展起来的。

This essay,by applying the Bipolar Diffusionism theory of Journalism and the Socialization theory of Sociology to analyze the causes of the sex aberration,puts forwards ways and measures to enhance the control of adolescent sex a...

依据传播学中"两级传播"理论与社会学中的社会化理论对性越轨行为的产生进行分析，从社会控制的角度提出了加强青少年网络性越轨控制的措施。

The dissertation presents a mathematical modeling approach for the high-speed flexible linkage mechanisms equipped with bonded piezoelectric sensing/actuating elements employing a mixed variational approach with Hamilton's principle in conjunction with the finite element formulation. This model includes both the terms coupling the elastic and rigid-body motions of linkage mechanisms and the terms coupling the elastodynamics and piezoelectricity of the elements, incorporating their effects upon the mass and stiffness matrices which are in general non-symmetric.

本文以国家自然科学基金资助项目《弹性连杆机构有害振动的主、被动控制及混合控制研究》（资助号：59605001）和广东省自然科学基金项目《开链及闭链机构有害振动控制研究》（资助号：970381）为依托，对高速弹性连杆机构振动的主动控制中的建模、求解、控制律的选择、作动/传感元件的优化以及实验研究等几个关键问题进行了比较深入细致的研究，取得了一些具有重要理论意义和重大实际应用价值的成果。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。