Straight-line compliant mechanisms are important building blocks to design a linear-motion stage, which is very useful in precision applications. However, only a few configurations of straight-line compliant mechanism...Straight-line compliant mechanisms are important building blocks to design a linear-motion stage, which is very useful in precision applications. However, only a few configurations of straight-line compliant mechanisms are applicable. To construct more kinds of them, an approach to design large-displacement straight-line flexural mechanisms with rotational flexural joints is proposed, which is based on a viewpoint that the straight-line motion is regarded as a compromise of rigid and compliant parasitic motion of a rotational flexural joint. An analytical design method based on the Taylor series expansion is proposed to quickly obtain an approximate solution. To illustrate and verify the proposed method, two kinds of flexural joints, cross-axis hinge and leaf-type isosceles-trapezoidal flexural（LITF） pivot are used to reconstruct straight-line flexural mechanisms. Their performances are obtained by analytic and FEA method respectively. The comparisons of the results show the accuracy of the approach. Both examples show that the proposed approach can convert a large-deflection flexural joint into approximate straight-line mechanism with a high linearity that is higher than 5 000 within 5 man displacement. This can lead to a new way to design, analyze or optimize straight-line flexure mechanisms.展开更多
联合战术信息分发系统(Joint Tactical Information Distribution System,JTIDS)作为Link16的通信载体为多军种协同作战提供服务。当前,高精尖武器装备的数量激增,进而JTIDS终端增多,导致非正交跳频层叠网间的邻频干扰和同频干扰发生的...联合战术信息分发系统(Joint Tactical Information Distribution System,JTIDS)作为Link16的通信载体为多军种协同作战提供服务。当前,高精尖武器装备的数量激增,进而JTIDS终端增多,导致非正交跳频层叠网间的邻频干扰和同频干扰发生的概率很大。基于此,分析了改用高斯最小频移键控(Gaussian Minimum Shift Keying,GMSK)调制后,JTIDS的频谱特征。同时,仿真分析了改进系统对于互干扰和同频干扰的健壮程度。仿真结果表明,在邻频干扰和同频干扰下,JTIDS误码率显著提高,使用复杂度更高的GMSK解调的JTIDS性能比原系统更好。展开更多
基金supported by National Natural Science Foundation of China(Grant No.51275552)Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No.201234)
文摘Straight-line compliant mechanisms are important building blocks to design a linear-motion stage, which is very useful in precision applications. However, only a few configurations of straight-line compliant mechanisms are applicable. To construct more kinds of them, an approach to design large-displacement straight-line flexural mechanisms with rotational flexural joints is proposed, which is based on a viewpoint that the straight-line motion is regarded as a compromise of rigid and compliant parasitic motion of a rotational flexural joint. An analytical design method based on the Taylor series expansion is proposed to quickly obtain an approximate solution. To illustrate and verify the proposed method, two kinds of flexural joints, cross-axis hinge and leaf-type isosceles-trapezoidal flexural（LITF） pivot are used to reconstruct straight-line flexural mechanisms. Their performances are obtained by analytic and FEA method respectively. The comparisons of the results show the accuracy of the approach. Both examples show that the proposed approach can convert a large-deflection flexural joint into approximate straight-line mechanism with a high linearity that is higher than 5 000 within 5 man displacement. This can lead to a new way to design, analyze or optimize straight-line flexure mechanisms.
文摘联合战术信息分发系统(Joint Tactical Information Distribution System,JTIDS)作为Link16的通信载体为多军种协同作战提供服务。当前,高精尖武器装备的数量激增,进而JTIDS终端增多,导致非正交跳频层叠网间的邻频干扰和同频干扰发生的概率很大。基于此,分析了改用高斯最小频移键控(Gaussian Minimum Shift Keying,GMSK)调制后,JTIDS的频谱特征。同时,仿真分析了改进系统对于互干扰和同频干扰的健壮程度。仿真结果表明,在邻频干扰和同频干扰下,JTIDS误码率显著提高,使用复杂度更高的GMSK解调的JTIDS性能比原系统更好。
