单级倒立摆基于LMI的H∞控制

采用拉格朗日方法对单级倒立摆系统进行了数学建模,并进行了稳定性、可控性、可观测性分析。针对单级倒立摆系统的控制问题,采用基于线性矩阵不等式(LMI)的H∞控制算法,并应用matlab对该倒立摆系统进行了仿真实验。结果表明,基于LMI的H∞控制方法考虑了被控对象中存在的各种不确定因素,抑制了扰动对输出的影响,系统的振荡小,调节时间短,响应速度快,使系统具有较强的鲁棒性和较好的动态性能,能够较好地完成倒立摆的运动控制。     

基于Atmega16的自主寻线避障智能车设计

设计并实现一种基于ATMEGA16单片机控制的自主寻线、避障、检测火焰并报警的智能小车。该智能车通过火焰传感器检测火焰,红外传感器检测轨道信息,红外对管检测障碍物,传感器将采集到的信息返回到单片机,单片机对信息做出相应的指挥控制,从而实现小车的自主寻线,稳定避障及检测火焰等功能。实验证明该小车寻线稳定、避障准确、检测火焰灵敏。     

不同管径水平管气液两相流流动特性数值模拟

为更好了解不同管径水平管气液两相流的压降特性,选用空气和水在管径分别为38.1,50.8,101.6 mm,长为9.525 m的水平管内进行气液两相流数值模拟,并结合理论分析了不同管径下水平管气液两相流压降的变化规律.利用Fluent软件研究结果表明:在同一管径下,当液速一定时,压降随气速的增大而增大;气速恒定时,压降...     

一种差速卷简的研究及应用

介绍了一种差速卷筒,该卷筒具有简单、轻质、负载能力大等特点,并能精确平稳地将高速旋转运动转化为低速直线运动。分析了差速卷筒的运动和受力特点,计算出了其危险截面上关键点的应力状态,并结合有限元优化设计方法设计了其筒壳壁厚,最后探讨了此类机构的仿真方法。     

基于深度学习的电机故障在线检测技术优化

为有效提高电机故障检测效率,研究建立了深度学习模型,并利用深度学习模型构建在线检测函数。试验结果表明,基于深度学习模型可以降低电机轴承振动干扰信号,以保证清晰识别特征频率,所建立的深度学习检测模型对电机轴承外部的外圈磨损、轴承缺口且有裂纹及保护架破损的精度及准确率均大于98.5%,而电机轴承内部的检测精度与准确率较低,但检测精度仍大于90%,可满足电机故障在线检测要求。研究成果可为电机故障在线检测提供理论参考。     

平面剪叉式机构通用运动学模型的建立与分析

以平面直角坐标的齐次坐标变换法为基础,介绍了一种平面剪叉式机构运动学建模方法;运用所得结论,对平面变比例剪叉式机构进行了运动学分析与仿真。文中介绍的平面剪叉式机构运动学模型建立与分析方法,理论清晰、运用简便、通用性强,为对剪叉式机构进行进一步的理论研究和设计制造,提供了依据和基础。     

一种齿条超越式内燃机的初步设计与研究

介绍了国内外内燃机功率传输机构的研究现状和存在的问题,研究了齿条超越式内燃机的结构和工作原理,对其功率传输及配气等系统进行了运动学分析和仿真,总结了齿条超越式内燃机的特点及存在的问题,最后指出齿条超越式内燃机是一种新颖独特的内燃机,能适合特定场合的应用,具有研究价值和应用前景.     

电子飞行包系统的设计与应用

电子飞行包会涉及到很多的新兴技术,如云技术、FMC、WMI等。通过对比分析,利用层次分析法,得出相对权重值较大的应用程序,再结合一些新技术新理念,提出对这些应用程序的设计方案建议,并对其涉及的技术功能进行介绍。     

Comparison of two types of twin-rotor piston engine mechanisms

A novel twin-rotor piston engine (TRPE) mechanism with high volumetric output and power density was introduced. This new engine comprises an energy conversion system and a differential velocity drive mechanism (DVDM). Two special geared four-bar mechanisms, DVDM-1 and DVDM-2, were utilized and compared. Based on the closed loop vector method, a mathematical model for position, velocity, and acceleration of the two mechanisms was established. Numerical examples illustrate that the kinematic characteristics were presented. Expression of the displacement and compression ratio of the two engine mechanisms were derived and compared. It is concluded that both DVDM-1 and DVDM-2 adopted in the proposed TRPE with six vane pistons create thirty-six power strokes per revolution of the output shaft, and the summation of two angles covered by each rocker is always 2π/N as the output shaft rotates an angle of π/N. In DVDM-1, the span angle of a vane piston should be designed to be 10.2°, and the compression ratio should be equal to 10; in DVDM-2, the span angle of a vane piston should be designed to be 10.6°, and the compression ratio should be equal to 4.3.     

Mathematical modeling and analysis of gas torque in twin-rotor piston engine

The gas torque in a twin-rotor piston engine （TRPE） was modeled using adiabatic approximation with instantaneous combustion. The first prototype of TRPE was manufactured. This prototype is intended for high power density engines and can produce 36 power strokes per shaft revolution. Compared with the conventional engines, the vector sum of combustion gas forces acting on each rotor piston in TRPE is a pure torque, and the combustion gas rotates the rotors while compresses the gas in the compression chamber at the same time. Mathematical modeling of gas force transmission was built. Expression for gas torque on each rotor was derived. Different variation patterns of the volume change of working chamber were introduced. The analytical and numerical results is presented to demonstrate the main characteristics of gas torque. The results show that the value of gas torque in TRPE falls to be less than zero before the combustion phase is finished; the time for one stroke is 30° in terms of the rotating angle of the output shaft; gas torque in one complete revolution of the output shaft has a period which is equal to 60° and it is necessary to put off the moment when gas torque becomes zero in order to export the maximum energy.