全文获取类型
收费全文 | 3326篇 |
免费 | 658篇 |
国内免费 | 595篇 |
专业分类
电工技术 | 1070篇 |
综合类 | 385篇 |
化学工业 | 76篇 |
金属工艺 | 61篇 |
机械仪表 | 395篇 |
建筑科学 | 5篇 |
矿业工程 | 19篇 |
能源动力 | 94篇 |
轻工业 | 4篇 |
水利工程 | 6篇 |
石油天然气 | 7篇 |
武器工业 | 98篇 |
无线电 | 193篇 |
一般工业技术 | 74篇 |
冶金工业 | 40篇 |
原子能技术 | 4篇 |
自动化技术 | 2048篇 |
出版年
2024年 | 53篇 |
2023年 | 154篇 |
2022年 | 149篇 |
2021年 | 192篇 |
2020年 | 248篇 |
2019年 | 298篇 |
2018年 | 178篇 |
2017年 | 231篇 |
2016年 | 255篇 |
2015年 | 227篇 |
2014年 | 260篇 |
2013年 | 312篇 |
2012年 | 215篇 |
2011年 | 242篇 |
2010年 | 169篇 |
2009年 | 190篇 |
2008年 | 161篇 |
2007年 | 183篇 |
2006年 | 157篇 |
2005年 | 123篇 |
2004年 | 117篇 |
2003年 | 79篇 |
2002年 | 62篇 |
2001年 | 58篇 |
2000年 | 42篇 |
1999年 | 34篇 |
1998年 | 28篇 |
1997年 | 29篇 |
1996年 | 29篇 |
1995年 | 22篇 |
1994年 | 10篇 |
1993年 | 15篇 |
1992年 | 16篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1954年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有4579条查询结果,搜索用时 15 毫秒
151.
This paper deals with the robust finite time tracking of desired trajectories for a wide group of robotic manipulators in spite of unknown disturbances, uncertainties, and saturations of actuators while only manipulator's positions are available and its velocities are not measurable physically. A new form of chattering‐free second order fast nonsingular terminal sliding mode control scheme is introduced to design input torques for fulfilling the determined tracking objective in the adjustable total finite settling time. The proposed control algorithm is incorporated with two nonlinear observers to estimate disturbances and velocities of joints within finite settling times. The global finite time stability of the closed‐loop manipulator is analytically proved. Finally, a numerical simulation is carried out to verify the effectiveness of the designed input torques. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
152.
Robust observer‐based stabilization of Lipschitz nonlinear uncertain systems via LMIs ‐ discussions and new design procedure 下载免费PDF全文
This paper presents a new observer‐based controller design method for Lipschitz nonlinear systems with uncertain parameters and ‐bounded disturbance inputs. In the presence of uncertain parameters, the separation principle is not applicable even in the case of linear time invariant systems. A state of the art review for uncertain linear systems is first presented to describe the shortcomings and conservatism of existing results for this problem. Then a new LMI‐based design technique is developed to solve the problem for both linear and Lipschitz nonlinear systems. The features of the new technique are the use of a new matrix decomposition, the allowance of additional degrees of freedom in design of the observer and controller feedback gains, the elimination of any need to use equality constraints, the allowance of uncertainty in the input matrix and the encompassing of all previous results under one framework. An extensive portfolio of numerical case studies is presented to illustrate the superiority of the developed design technique to existing results for linear systems from literature and to illustrate application to Lipschitz nonlinear systems. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
153.
This paper investigates the observer based fault accommodation (FA) problem for linear systems with state perturbations and measurement errors. A novel intermediate estimator is proposed to estimate the state and the faults simultaneously, where the effect of state perturbations and measurement errors can be effectively eliminated by fully exploiting the design freedom of some specified parameters. Based on the estimation, a fault tolerant control (FTC) scheme is synthesized. It is proved that the states of the resulting closed loop system are uniformly ultimately bounded with an explicit bound. Simulation examples verify the effectiveness of the proposed method. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
154.
《计算机辅助绘图.设计与制造(英文版)》2013,(3):28-32
Road friction coefficient real-time estimation methods is an important issue and problem in automotive active safety con- trol system development. First a fixed feedback gain sliding mode observer of road adhesion coefficient is designed through the es-tablishment of tire/road dynamic friction model in this article. The simulation results shows that the observer can well real-time iden-tify the current road adhesion characteristics. And more importantly, the observer only need wheel speed signal and the braking torque (brake pressure) signal, so the system is low cost, and its adaptability is good. There is no doubt this estimation method has a good application prospect. 相似文献
155.
提出一种交流伺服系统的离散域复合控制方案,可实现在未知负载条件下的准确位置控制。基于永磁同步电机伺服系统中位置与速度环组成的数学模型,以电机转角位置作为系统的测量反馈信号,设计一个降阶线性扩展状态观测器对电机转速(未量测)和未知负载扰动加以估计,并用于反馈控制和扰动补偿。采用TMS320F2812DSP在一台实际的永磁同步电机上进行了实验测试,结果表明伺服系统能在未知负载情况下实现平稳和准确的目标位置跟踪,且对负载和参数差异具有较好的鲁棒性。这种控制方案可方便地应用于相关的伺服系统。 相似文献
156.
It is shown that, for any time-invariant exponentially stable linear system with additive disturbances, time-varying exponentially stable interval observers can be constructed. The technique of construction relies on the Jordan canonical form that any real matrix admits and on time-varying changes of coordinates for elementary Jordan blocks which lead to cooperative linear systems. The approach is applied to detectable linear systems. 相似文献
157.
基于前件变量未知的T-S模糊系统设计一类模糊观测器.将模糊系统转化为广义系统的形式,提出一种广义系统的观测器设计方法,消除了控制输入对观测误差方程的影响.针对测量端含有扰动的模糊系统,通过拉格朗目中值定理,将模糊观测器转化为一组线性矩阵不等式的求解问题,并将这种观测器的设计方法应用到熔化极气体保护焊系统,快速有效地实现了对弧长的观测.最后通过仿真分析验证了所提出的观测器设计方法的有效性. 相似文献
158.
159.
基于无源性的异步机自适应控制 总被引:2,自引:0,他引:2
对近年来出现的一种异步机控制方法--基于无源性的控制(简称PBC)进行了发
展,从理论上取消了对定子电流反馈的要求,并针对转子电阻变化,增加了参数自调整的自
适应控制和转子磁链闭环控制.该控制器保留了PBC方法的简单、无奇异点等优点,而且抑
制了由于转子电阻变化引起的转速和磁链跟踪误差. 相似文献
160.
给出了线性系统函数观测器的一个新的参数化表示,并分析了其物理意义及状态空
间解释.本文得到的函数观测器的阶数比已往的结果降低了系统的输出数 相似文献