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1.
The robot techniques development is making over in an astonished velocity. Today ,all kinds of robots have different shape and function appear in everywhere. The robot that used the turning theory of human being and the motion theory of cankerworm is introduced. Micro-robot is an important offset of robot technique. This paper has solved three problems of this kind of micro-robot. One is the mechanical structure design, and the second is controlling circuit design, the third is measurement system design. Two new pattern micro-robots have been made which not only can move on the smooth armor plate, but also can turn its body quickly and freely. This new pattern micro-robot has strongly driving power, which also can be refitted another walking-type robot. At the same time, it also succeeded in controlling the robot through the microprocessor AT89C52 and the other new type controlling circuit. Taking the chip of LG9110 as the positive and negative driver, and the chip of SN75451B as the driver of the other parts, not only the design of circuits become easily, but also circuit board become simply. It provides some diagrams of program. In short, through the experiment, it gains some important data of making this kind of robot on the other hand, the experiment proves that the project not only can control the robot freely, but also offers a new idea for the studying of this kind of micro-robot.  相似文献   

2.
The burning rate of hydrogen air pre mixture on meso scale is mainly determined by its chemical reaction rate. So a Laminar Finite Rate Model, the gas phase reaction mechanism for the combustion of hydrogen air mixture which consists of 19 reversible elementary reactions and the dynamic mesh method are adopted to simulate the combustion of hydrogen air mixture in a meso scale IC engine which operates a quasi gas power cycle under ultrahigh combustion load. The combustion of hydrogen air mixture on meso scale in the micro combustion chamber with moving boundary can be stable. The complete thermodynamic process of heat addition, internal energy increasing, and a boundary work output producing during expansion can be perfectly achieved in the closed combustion system of the meso scaled IC engine igniting the hydrogen air mixture by wire surface of high temperature. However, running parameters such as cycle period, initial pressure and fuel/air ratio have complex effects on the hydrogen air combustion of micro closed container with moving boundary.  相似文献   

3.
In order to make good use of power line carrier to communicate, it is necessary to analyze the time-variable, impedance,attenuation and noise characteristics of low voltage power line. The waves of every characteristic have been experimented. At the same time, aiming at these characteristics, some available measures are given in order to conquer the disadvantage factors. The experimental results show that some suitable carrier communication modes must be adopted to realize ideally the carrier communication on low voltage power line.  相似文献   

4.
VPN is a technology that realizes the security transmission of private information through the public network. As one of key technologies, tunnel technology resolves the mobility problem of mobile nodes. Firstly, L2TP and IPSec have been compared based on these two tunnel principles introduction of VPN. Secondly the advantages of IPSec in security have been introduced. Then, the problems of mobile host and two models of tunnel in VPN have been introduced. Lastly, the advantages of utilizing the mobile IP to resolve the problem of mobile host have been analyzed, and this technology has been compared with VPDN.  相似文献   

5.
To resolve the kinematics modeling and dynamics modeling of a humanoid robot with complicated machine, a modeling method based on the conventional mechanism combined with neural network is presented. First the kinematics formulas are deduced by analyzing its geometry structure. Second, the dynamics models are built up with Lagrange-Euler method combined with the define of interactive force among all parts of the humanoid robot. The interactive force is realized by neural network method. Finally, the true robot parameters are applied to the model. The simulation results show the validity of the modeling. So, the method is practical and available.  相似文献   

6.
李治  安岩  侯丽薇 《中国农学通报》2018,34(16):157-164
为了系统研究农村一二三产业融合发展在必然性、内涵特征、动因机制、模式路径、存在问题等方面的理论成果,推动相关研究的成熟和完善。综合运用文献资料法和对比分析法,梳理总结了相关研究关于中国农村土地资产市场的研究成果,分析了农村一二三产业融合发展的必然性,分析了农村一二三产业产业融合的内涵特征和动因机制,介绍了农村一二三产业融合的模式路径,指出了农村一二三产业融合面临的问题,总结了农村一二三产业融合进一步发展的政策建议。研究认为:目前国内关于农村一二三产业融合的研究集中于内涵与模式以及问题与对策等方面,主要是基于农村产业融合案例采用实地调研、经验总结、定性分析等方法,而对于农村三产融合发展的深层次分析研究并不多见;未来的研究可重点关注微观行为主体:深入分析农户、企业、中介组织、政府的融合行为特征及其原因,探索建立农户、企业、中介组织等融合主体间的利益联结机制。  相似文献   

7.
Perilous rock is a dominant geological hazard in Three Gorges Reservoir area of P. R. China. The Taibaiyan cliff at Wanzhou is a representative case of massive perilous rocks in the area. Using this cliff as an example, the conditions triggering massive perilous rocks were studied and described. This included examining the following three conditions: alternating layers of mudstone and sandstone; steep landforms such as cliffs or scarps; and intense rainfall. The massive development mechanism for perilous rocks was discussed, including micro chained pattern gradual and interval evolution from the bottom to the summit of the cliffs individually as perilous rock, and a macro chained pattern evolving stage by stage from the cliff face backward up the mountain. In some respects, rock cells below sandstone in cliffs serves as the pulsating valve of the massive development mechanism for perilous rock. In any micro chained pattern, perilous rock situated on summits is the easiest to rupture due to the fissure pressure. For any single perilous rock, two load compositions were derived. In addition, methods for analyzing perilous rock stability were established in detail using the limit equilibrium principle. Two key techniques, a union scheme that both supports and anchors and a union scheme that nails and anchors, are proposed in light of the massive development mechanism for perilous rock.  相似文献   

8.
The path following control of a new type of 4-wheel differential omnidirectional mobile robot is studied. Based on the kinematics model and the artificial driving thought, a new kind of control method, i.e. following two reference point, which is different to the traditional following single point method, is designed. The proposed method adopts master-slave control model of the front and rear differential unit and separates the angular velocity control and velocity control of the differential unit to independently design the fuzzy controller. At last, the most representative path, the sine curve path following is simulated and the results show that the following control strategy is feasible, small overshoot, rapid responding and resolves the complex system with high degree of coupling in the following single point control.  相似文献   

9.
Combined microwave-convection drying characteristics are investigated by numerical simulation. Combined microwave-convection drying has advantage of swift drying and sterilization. Based on qualitative analyses on the mechanism of combined microwave-convection drying, the differential equations are established and the numerical simulation method is described. The humidity, vapor pressure and temperature, along the radius in a spherical pill, are calculated by the numerical simulation during drying process. The calculation results show the relationship between humidity, vapor pressure, temperature and drying time, and that drying process is greatly influenced by input microwave power. The calculation results are good consistent with the experimental datum.  相似文献   

10.
微型内燃机微燃烧过程对当量比和转速变化非常敏感,采用层流有限速率模型和甲醇氧化反应机理对其预混层流微燃烧过程开展仿真研究,探讨当量比和转速对微燃烧特性的影响规律及临界运行参数。在此基础上,提出采用热着火理论和化学反应动力学理论探索当量比对微燃烧特性的影响机理。结果表明仿真与实验比较吻合。当量比从0.6增加到1.1时,燃烧速率增加,压力和温度增加,压力最高值增加约1.5E+6 Pa,温度最大值增加约1 300 K,此后随当量比增加,燃烧速率减小,压力和温度减小。研究还进一步揭示了当量比影响微燃烧特性的机理: 稀燃区当量比主要通过温度变化来影响微燃烧特性,随当量比增加,燃料浓度增加,燃烧释放的总热量增加,所以温度和压力增加,燃烧速率增加;浓燃区当量比主要通过氧气量变化来影响微燃烧特性,当量比越大,氧气量越不足,基元反应速率越小,所以燃烧速率越小,温度和压力越低。转速越高,燃烧时间越短,燃烧越不充分,所以温度、压力越低。受微燃烧相对热损大、驻留时间短的特征影响,微型发动机实现完全燃烧的运行区域较窄,其实现完全燃烧的稀燃极限约0.9,最高转速约6 000 r/min。这在设计微型内燃机时值得关注。  相似文献   

11.
酪蛋白是牛奶中的主要蛋白成分,因其酶解产物中可分离出多种生物活性肽而广受关注。综述了酪蛋白的结构及其酶解特性的研究进展。酪蛋白由α_(s1)-酪蛋白、α_(s2)-酪蛋白、β-酪蛋白与κ-酪蛋白4种组分组成,在溶液中以胶团形式存在,其稳定性除与κ-酪蛋白有关外,还受到外界环境的影响,然而对于酪蛋白胶团内部结构的推断仍存在争议。此外,全酪蛋白及其组分的酶解特性也得到了较深的研究,包括推断酶解反应历程、酶解产物分子量分布变化、蛋白结构功能特性的变化及生物活性肽段序列的确定等。  相似文献   

12.
Cone enveloping cylindrical worm in traction machine as instance, theoretical analysis on cylindrical worm transmission has been theoretically analyzed, and efficiency test and load capability test of traction machine with YJ240 cylindrical worm have been done on open power gear experimental instrument. According to the experimental data, it indicates cylindrical worm have some weaknesses on load capability, efficiency, adjustment possibility of tooth backlash and so on. Therefore, on purpose of improving integral performance of traction machine, face worm with variable tooth thickness may be used as primary drive mechanism in traction machine instead of cylindrical worm.  相似文献   

13.
本研究以河西走廊荒漠绿洲边缘关键天然固沙植物沙拐枣为研究对象,对流动沙丘、固定沙丘不同生境的沙拐枣种群扩张特征进行调查,旨在更全面地认识其种群扩张特征和对干旱高温环境的适应对策。结果表明:(1)沙丘不同生境,沙拐枣种群扩张方式存在显著差异:在流动沙丘,丘间低地和过渡带以有性繁殖为主,无性繁殖为辅;迎风坡和背风坡以无性繁殖为主;而随着流动沙丘固定,种群以有性繁殖为主,无性繁殖数量和所占比重显著下降,并导致种群数量下降。(2)不同生境中沙拐枣种群密度与年龄均呈显著负相关,种群以幼龄苗为主,种群最大年龄出现在丘间低地,为36龄。(3)流动沙丘不同生境根状茎主要为2年生,多年生根状茎长度较短;而固定沙丘不同生境根状茎年龄结构较为均衡。  相似文献   

14.
The problem that the micro-glassball is not wettable in molten aluminium alloys can be solved by a special technology that is different from rheocasting and squeezecasting methods. The metten metal can fill the cavity of the glass ball through the broken place on its wall, and an original micro -structure will be formed. This material has good comprehensive mechanical proper ties and this method can be used to other kinds of ceramic powders. The mechanisms of the formation of this materials have been discussed as well.  相似文献   

15.
提出了一种包含了逆变器接口(voltage source inverter,VSI)、同步电机接口(synchronous generator,SG)的独立微网控制策略,并分析了其小信号稳定性。VSI接口和SG接口的分布式电源均采用下垂控制策略,二者之间无需实时通信,可实现负荷功率共享。建立了系统的小信号状态空间模型,主要包括:同步发电机及其控制器的小信号模型、逆变器及其控制器的小信号模型、电网络及负荷小信号模型。计算了下垂增益变化时的根轨迹,得到了系统主特征值随参数变化的根轨迹,计算了不同状态变量对特征值的参与因子。稳定性分析结果表明:当所有分布式电源采用下垂控制时,引入同步发电机接口的分布式电源,系统频率小信号稳定性大大增强。PSCAD时域仿真验证了特征值计算的正确性。  相似文献   

16.
The aufhors calculate and analyze the arcing grounding overvoltage of 10 kV power network in case of neutral ungrounded and grounding through nonlinear resistance using EMTP, with a actual 10 kV power network of a substation in Guizhou province as an example. The emulational calculation results show that the grounding method which grounds through nonlinear resisitance has the advantages of the other two methods, can better limit the arcing grounding overvoltage and can not stop the power supply .even one phase is grounded by fault, so it can ensure the security of the power networkg supply . the network neutral grounding through nonlinear resistance needs more deep study and analysis as a new network neutral grounding mehtod.  相似文献   

17.
In this paper,the parametric equation of a hydraulic excavator workwpace areestablished by using the spatial mechanism theory of robot.Characteristic points of the workspaceboundary are searched by the optimization procedure and the calculate formula of area of theworkspace longitudinal section is found.  相似文献   

18.
智能机器人在农业自动化领域的主要应用   总被引:3,自引:0,他引:3  
赵欣 《中国农学通报》2010,26(10):360-364
通过对智能机器人在农业自动化领域的主要应用进行研究,包括采摘机器人、嫁接机器人、耕耘机器人、除草机器人、喷农药机器人、插秧机器人、林木清洁机器人、饲喂机器人、禽蛋检测与分级机器人。发现应用于农业智能机器人的主要技术有感知与避障技术、机器视觉技术、信息融合技术及农业专家系统。农业机器人的智能问题、成本过高问题和易受环境变化的影响问题,需要进一步研究解决。  相似文献   

19.
In order to decrease the consumption of the limited bandwidth resource and the electronic power of mobile battery, fixed paging area strategy is adopted in most mobile communication networks currently. Although its application is very simple, it cannot reach the best performance. In allusion to this problem, we introduce four kinds of improved mobile paging strategies, and analyze their concrete implementation methods briefly. Their performances are compared with fixed paging area strategy. Moreover, the benefits,the drawbacks and the range of application of each scheme are pointed out for future study.  相似文献   

20.
The production theory and the production process of MnN by solid-nitration process with manganese power is introduced. In order to obtain MnN, manganese power has been nitrided by pure nitrogen at high temperature in pipe-type-oven at lab. Suitable nitration technical parameters, such as manganese power size, nitriding temperature and nitriding time have been gotten by a series of experiments. MnN production that nitrogen content is 6.94% has been obtained. In addition, three alloys composed manganese nitrogen (Mn_(3)N_(2), Mn_(2)N,Mn_(4)N) have been obtained and their distributions are observed by the way of XRD and SEM.  相似文献   

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