全文获取类型
收费全文 | 9554篇 |
免费 | 721篇 |
国内免费 | 579篇 |
学科分类
工业技术 | 10854篇 |
出版年
2024年 | 26篇 |
2023年 | 71篇 |
2022年 | 164篇 |
2021年 | 161篇 |
2020年 | 237篇 |
2019年 | 154篇 |
2018年 | 147篇 |
2017年 | 303篇 |
2016年 | 286篇 |
2015年 | 374篇 |
2014年 | 664篇 |
2013年 | 483篇 |
2012年 | 796篇 |
2011年 | 923篇 |
2010年 | 720篇 |
2009年 | 686篇 |
2008年 | 623篇 |
2007年 | 824篇 |
2006年 | 725篇 |
2005年 | 615篇 |
2004年 | 444篇 |
2003年 | 345篇 |
2002年 | 277篇 |
2001年 | 179篇 |
2000年 | 153篇 |
1999年 | 129篇 |
1998年 | 77篇 |
1997年 | 61篇 |
1996年 | 39篇 |
1995年 | 39篇 |
1994年 | 41篇 |
1993年 | 25篇 |
1992年 | 13篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1959年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
文章简要阐述了PID码在多节目码流的复用与解复用中所起的作用。并运用PID码的原理来解释和解决在实际工作中碰到的PID码问题。 相似文献
2.
在大空间的温度控制系统中 ,采用简单的PID控制规律 ,对空间的温度、湿度进行解藕计算 ,将空间的相对湿度控制转化为送风含湿量的控制。该控制方式稳定、可靠 ,并且节约能源。本方法适用于所有的烘烤炉中 相似文献
3.
4.
In this paper, a robust control system is first proposed which is suitable for the control of a class of nonlinear systems. A parallel connection of a relay to a proportional integral derivative (PID) controller collectively forms the robust controller. The relay ensures robust control by providing a high feedback gain, but it also induces a control chattering phenomenon. Instead of viewing chattering as an undesirable yet inevitable feature, the chattering signals are used as natural excitation signals for identifying an equivalent PID controller using the recursive least squares algorithm. No other explicit input signal is required. Analysis is provided on the stability properties of the control scheme. Simulation results for the level control of fluid in a spherical tank using the scheme are presented. 相似文献
5.
在宝钢钢管调质炉(IPSEN炉)控制系统的改造中,用西门子S7-400的PID功能软件模块改造原模拟调节器,以实现加热调质温度控制.介绍了用S7-400的PID控制模块构成淬火炉、淬火油槽、回火炉温度控制的方法,并由此提出对宝钢钢管生产中其它加热炉控制系统改造的选择方案. 相似文献
6.
杨丽娟 《工业仪表与自动化装置》2003,(4):14-15
根据目标值滤波器型二自由度PID控制器,提出一种新型二自由度PID控制器。实验表明该算法使用可靠、精度高,而且具有较强的抗干扰能力和鲁棒性,可大大提高系统的控制品质。 相似文献
7.
设计研制了一种带模糊控制的新型单回路可编程调节器 ,该调节器不仅适用于一般的线性控制对象 ,也适用于中和滴定、球罐液位控制等非线性对象和复杂的工业对象 ,实现了多种常用的控制算法 ,在工业中有很好的实用价值 相似文献
8.
Gerardo Gabriel Acosta Miguel Angel Mayosky José Maria Catalfo 《Applied Intelligence》1994,4(1):53-66
This article proposes a scheme for the on-line adjustment of three mode controller settings based on experimental measurements of closed-loop performance. It uses a recently developed heuristic tuning procedure to identify estimated process parameters. This method may give rise to conflicting estimates. Fuzzy Set theory is applied to manage the situation in terms of a fuzzy conjunction to combine the various estimates. PID control was chosen because of its wide use in the industrial environment due to driving simplicity and robustness. The article shows design, development, and computer simulation aspects. 相似文献
9.
The human pelvis is such a unique structure that enables our upper body to work so perfectly with the two legs so as to control the body's balance in the complicated postures. The aim of this study is to establish a new dynamic body sway control model in the upright standing body position in coronal plane, and to reveal the possible control mechanisms underlying the body sway with special concerns on the roles that the pelvis and its muscles are performing during the sway. The plant of control model, the dynamics of human body, includes five parts, i.e. two ankles, two hips and one lumbosacral joint, which makes up a multi‐link inverted pendulum system, and is driven by two pairs of muscles, the psoas major (PM) and glutaeus medius (GM). Body sway records from eight healthy young subjects showed that the angular sway scopes of the ankle on roll (lateral) plane are 0.94±0.36± (eye‐open) and 1.35±0.52± (eye‐closed) respectively, while in lumbosacral plane, the scopes are 0.99±0.41± (eye‐open) and 1.27±0.72± (eye‐closed). The ankle and lumbosacral sways were almost in the same degree, yet their phase difference was near ±n, which means that the body trunk maintains perpendicular to horizon during the upright stance. Surface electromyographic (sEMG) activity from GM also showed the same evidence: the activated GM was always in the same side as the deviated center‐of‐pressure (COP). By assuming the corrective torque of posture is regulated by PID (proportional, integral and derivative) control, the body sway can be simulated by applying human physical parameters. Our study results demonstrated that the simulated traces are consistent with the experimental recorded, suggesting that the pelvis is an important structure for the posture maintenance and control, and the mechanism of balance keeping control during upright stance can be approximately taken as a PID control. The result also suggests a novel means for postural stability assessment in individual in the future. 相似文献
10.
This article presents a design of the internal model control(IMC)based single degree of freedom(SDF) fractional order(FO)PID controller with a desired bandwidth specification for a class of fractional order system(FOS). The drawbacks of the SDF FO-IMC are eliminated with the help of the two-degree of freedom(TDF)FO PID controller. The robust stability and robust performance of the designed controller are analyzed using an example. 相似文献