首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15093篇
  免费   1610篇
  国内免费   1180篇
电工技术   745篇
综合类   1721篇
化学工业   262篇
金属工艺   1187篇
机械仪表   3617篇
建筑科学   324篇
矿业工程   319篇
能源动力   84篇
轻工业   223篇
水利工程   77篇
石油天然气   110篇
武器工业   214篇
无线电   1185篇
一般工业技术   913篇
冶金工业   168篇
原子能技术   90篇
自动化技术   6644篇
  2024年   103篇
  2023年   338篇
  2022年   521篇
  2021年   595篇
  2020年   598篇
  2019年   446篇
  2018年   488篇
  2017年   493篇
  2016年   556篇
  2015年   628篇
  2014年   910篇
  2013年   934篇
  2012年   995篇
  2011年   988篇
  2010年   765篇
  2009年   879篇
  2008年   783篇
  2007年   1072篇
  2006年   938篇
  2005年   842篇
  2004年   735篇
  2003年   634篇
  2002年   427篇
  2001年   433篇
  2000年   316篇
  1999年   214篇
  1998年   191篇
  1997年   197篇
  1996年   126篇
  1995年   112篇
  1994年   130篇
  1993年   86篇
  1992年   86篇
  1991年   79篇
  1990年   64篇
  1989年   65篇
  1988年   51篇
  1987年   9篇
  1986年   11篇
  1985年   5篇
  1984年   9篇
  1983年   9篇
  1982年   3篇
  1981年   3篇
  1980年   3篇
  1977年   3篇
  1976年   2篇
  1975年   3篇
  1972年   1篇
  1971年   2篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
31.
介绍BOSCH伺服控制系统成功应用于ZJ19B卷接机组传动系统中,使机器供丝、供纸、刀头、嘴机部分各个电机的运行更加稳定,控制精度显著提高;减少因控制精度不够而引起的非正常停机次数,提高机器的有效作业率,节约原料;同时使烟支的重量、圆周、紧头等各项指标合格率显著提高。  相似文献   
32.
本文关于贝加莱ACOPOSmulti伺服系统和机器人软件库在奇瑞6关节机器人研发中的应用。介绍了机器人机械系统的组成和性能参数,重点描述了以APC820工控机和ACOPOSmuhi伺服驱动器为核心。基于EthernetPOWERLINK工业实时以太网和AutomationStudio集成软件开发平台的机器人控制系统,并讨论了通过MATLAB/Simulink的代码自动生成技术、ACOPOSmuhi驱动系统的负载惯量前馈技术等关键技术环节。  相似文献   
33.
A robustness analysis and synthesis for incomplete nonlinear decoupling for a class of nonlinear systems is discussed. Rigid and elastic-joint robot models belong to this class. For the elastic case, a transformation facilitates the robustness analysis under a weak assumption. Charts with H 1- and H - norms of closed-loop disturbance transfer functions of the nonlinear-decoupled system are presented for a robust pole assignment.  相似文献   
34.
Ladder handling by telecommunications technicians represents an indispensable part of their daily work, but may generate musculoskeletal injury risk. These workers have a high prevalence of shoulder and back injuries, motivating research to quantify postures and loading using different ladders during common handling tasks. Twenty-five participants completed carry, raise (against a wall or free standing), and simulated removal from a van roof tasks using three ladders (8.5m 2-piece wood; 8.5m 2-piece fibreglass, 9.2m 3-piece wood). Data collection included kinematics and kinetics during these ladder handling tasks, as well as perceived discomfort, perceived exertion and post-collection ladder and task preferences. Significant effects depended on task and ladder. Dominant arm (the arm completing the primary action) elevation was higher while extending the ladder (114.7 ± 3.4°) than the carry task (53.5 ± 3.5°) (p < 0.05). Joint moments in the dominant shoulder and trunk were highest for the 2-piece wood ladder (59.0 ± 2.2 Nm and 254.8 ± 8.8 Nm) averaged across all tasks. Joint forces were increased when using the 2-piece wood ladder compared to the 3-piece wood ladder (p < 0.05), while the greatest discomfort in the shoulders occurred using the 2-piece wood ladder in the carry task. Many tasks approached or exceeded strength capability of a 50th percentile male's predicted strength. While no ladder universally mitigated physical demands while lowering perceptual difficulty, construction differences yielded trends toward preferring the 2-piece fibreglass or 3-piece wood ladders over the 2-piece wood ladder. This work has direct relevance to workplaces with ladder handling and provides recommendations for ladder selection and strength requirements across tasks.  相似文献   
35.
Cyber-physical production systems enable adaptivity and flexibility when manufacturing customized products in small batches. Due to varying routes and a high variance of workpieces, material flows in cyber-physical production systems can get highly complex, which can lead to physically induced disturbances that can result in accidents or decreased throughput and high costs. This issue can be addressed by applying a physics engine to simulate the physical interaction between workpieces and the material handling systems during the operation. Connecting such a digital model to a real material handling system in order to derive simulation-based decision support leads to the concept of digital twins. To date, few practical implementations of digital twins in manufacturing outside the machine tool domain were reported. Therefore, this paper describes the modeling and the subsequent implementation of an integrated system that consists of a real material handling system and its digital twin, based on physics simulation. A practical use case demonstrates the versatile advantages of the implemented solution for a manufacturing system with respect to the three digital twin functions prediction, monitoring and diagnosis.  相似文献   
36.
Although ground robots have been successfully used for many years in manufacturing, the capability of aerial robots to agilely navigate in the often sparse and static upper part of factories makes them suitable for performing tasks of interest in many industrial sectors. This paper presents the design, development, and validation of a fully autonomous aerial robotic system for manufacturing industries. It includes modules for accurate pose estimation without using a Global Navigation Satellite System (GNSS), autonomous navigation, radio-based localization, and obstacle avoidance, among others, providing a fully onboard solution capable of autonomously performing complex tasks in dynamic indoor environments in which all necessary sensors, electronics, and processing are on the robot. It was developed to fulfill two use cases relevant in many industries: light object logistics and missing tool search. The presented robotic system, functionalities, and use cases have been extensively validated with Technology Readiness Level 7 (TRL-7) in the Centro Bahía de Cádiz (CBC) Airbus D&S factory in fully working conditions.  相似文献   
37.
Key areas of robot agility include methods that increase capability and flexibility of industrial robots and facilitate robot re-tasking. Manual guidance can achieve robot agility effectively, provided that a safe and smooth interaction is guaranteed when the user exerts an external force on the end effector. We approach this by designing an adaptive admittance law that can adjust its parameters to modify the robot compliance in critical areas of the workspace, such as near and on configuration singularities, joint limits, and workspace limits, for a smooth and safe operation. Experimental validation was done with two tests: a constraint activation test and a 3D shape tracing task. In the first one, we validate the proper response to constraints and in the second one, we compare the proposed approach with different admittance parameter tuning strategies using a drawing task where the user is asked to guide the robot to trace a 3D profile with an accuracy or speed directive and evaluate performance considering path length error and execution time as metrics, and a questionnaire for user perception. Results show that appropriate response to individual and simultaneous activation of the aforementioned constraints for a safe and intuitive manual guidance interaction is achieved and that the proposed parameter tuning strategy has better performance in terms of accuracy, execution time, and subjective evaluation of users.  相似文献   
38.
针对两轮驱动机器人运动模型定向误差的累积问题,提出改进的三轮驱动机器人运动模型,对EKF-SLAM算法的一致性进行改进;该模型通过对机器人车轮线速度的解耦运算,将机器人运动过程中的旋转角速度提取出来并作为系统的控制输入之一,从而可以直接得到各个控制时间间隔内的机器人姿态角变化,很好地避免了机器人定向误差的累积;最后,基于归一化估计方差的检验标准进行实验,验证了三轮驱动机器人运动模型有效提高了EKF-SLAM算法的一致性。  相似文献   
39.
介绍一种以ARM为核心的嵌入式服务机器人体感遥控器的设计。硬件上,本遥控器采用具有ARM Cortex—M3内核的STM32F103C8T6作为核心处理器,选用ST公司的iNEMO惯性导航模块进行手部姿态的识别,同时还具有LCD显示模块、无线收发模块和电源模块;软件上,采用嵌入式操作系统μC/OS—Ⅱ实现多任务的调度和外围设备的管理。经实验验证,本遥控器具有高稳定性、高实时性、高可靠性、低误码率等优点。  相似文献   
40.
A new visual servo control scheme for a robotic manipulator is presented in this paper, where a back propagation (BP) neural network is used to make a direct transition from image feature to joint angles without requiring robot kinematics and camera calibration. To speed up the convergence and avoid local minimum of the neural network, this paper uses a genetic algorithm to find the optimal initial weights and thresholds and then uses the BP algorithm to train the neural network according to the data given. The proposed method can effectively combine the good global searching ability of genetic algorithms with the accurate local searching feature of BP neural network. The Simulink model for PUMA560 robot visual servo system based on the improved BP neural network is built with the Robotics Toolbox of Matlab. The simulation results indicate that the proposed method can accelerate convergence of the image errors and provide a simple and effective way of robot control.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号