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1.
研究了平面腿型跳跃机器人浮动基动力学模型的建立、仿真及试验问题.将跳跃机器人模型抽象成由三根均质连杆组成的平面跳跃机构,建立3个坐标系研究跳跃运动的变约束性.分别对支撑相和腾空相的运动模型进行分析,建立了Lagrange动力学方程.由于支撑相足尖与地面满足Pfaffian约束,因此将机器人足尖平移坐标与关节变量统一作为广义坐标,建立显含力约束的跳跃机器人浮动基动力学模型.确定跳跃运动约束方程和相互识别条件.通过仿真和样机试验说明了跳跃机器人浮动基动力学模型的正确性.  相似文献   

2.
采用动静法建立振动系统动力学方程,通过具体例子的讨论和一般情形的分析,论证了振动方程的耦合类型与系统广义坐标选取无关.  相似文献   

3.
建立了开环多刚体系统的四元数动力学方程,以滑移矢量和相对转动四元数为广义坐标,并运用广义达朗贝尔原理及广义虚功原理建立的这一动力学方程消除了奇点,便于数值计算。以一无约束的空间2刚体系验证了四元数多刚体系统动力学方程的正确性和适用性。  相似文献   

4.
建立了开环多刚体系统的四元数动力学方程,以滑移矢量和相对转动四元数为广义坐标,并运用广义达朗贝尔原理及广义虚功原理建立的这一动力学方程消除了奇点。便于数值计算。以一无约束的空间2刚体系验证了四无数多刚体系统动力学方程的正确性和适用性。  相似文献   

5.
借助广义坐标、不计算广义力,从能量和功率观点建立完整系统动力学方程的一种形式,为解决多自由度系统动力学问题提出简捷解法。对于相当广泛的一类系统,这种方法与传统的Lagrange方程比较,物理意义更为明显,计算简捷。  相似文献   

6.
借助于广义坐标、能量和广义功率的观点建立非完整系统动力学方程的一种形式。  相似文献   

7.
研究了一种由直角坐标机构、转动机构和摆动机构构成的自主研磨作业机器人的运动学和动力学分析,以支链构件相对坐标和动平台绝对坐标作为广义坐标,结合Lagrange方法建立了运动学和动力学模型,并利用Matlab软件平台进行了运动学及动力学仿真,仿真结果说明了该模型的正确性与实效性,进而为自主作业机器人的轨迹规划及控制研究提供参考。  相似文献   

8.
本文导出了一般开链挠性机器人机构动力学方程。它是由关节广义坐标和杆件模态坐标联立的非线性微分方程组。对于一般形状的杆件,采用有限元离散化,将节点物理坐标转换到模态坐标,利用弹性模态的正交性简化计算,给出了广义惯性阵元素的显式表达式。对方程进行了讨论和简化。  相似文献   

9.
对三种较为典型的柔性传动系统,先用拉格朗日方程建立动力学数学模型,再选取适当的广义坐标,通过线性变换,得到各集中质量位于同一轴线的等效模型,从而使原模型向实际典型的三类柔性传动系统转化,得到相应柔性传动系统三种动力学数学模型。  相似文献   

10.
针对弹跳机器人高驱动功率的要求,设计了一种含有弹簧储能机构的间歇式跳跃仿蛙机器人。为了分析机器人在弹簧储能机构驱动下的起跳运动规律,对机器人起跳阶段的动力学进行了研究。首先建立了简化的机器人机构模型,并采用D-H方法建立了机器人起跳阶段的位置、速度和加速度方程;然后根据多刚体动力学拉格朗日方法推导了机器人起跳阶段的动力学方程,并利用MATLAB对拉格朗日方程进行数值求解,得到了机器人起跳阶段的关节角度变化规律、质心运动轨迹和起跳完成时刻质心速度。最后利用ADAMS进行了起跳阶段的动力学仿真,验证了动力学方程数值求解结果的有效性。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

19.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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