Exploration on 2D DOA Estimation of Linear Array Motion:Uniform Linear Motion

Generally,due to the limitation of the dimension of the array aperture,linear arrays cannot achieve two-dimensional(2D)direction of arrival(DOA)estimation.But the emergence of array motion provides a chance for that.In this paper,a generalized motion scheme and a novel method of 2D DOA estimation are proposed by exploring the linear array motion.To be specific,the linear arrays are controlled to move along an arbitrary direction at a constant velocity and snap per fixed time delay.All the received signals are processed to synthesize the comprehensive observation vector for an extended 2D virtual aperture.Subsequently,since most of 2D DOA estimation methods are not universal to our proposed motion scheme and the reduced-dimensional(RD)method fails to handle the case of the coupled parameters,a decoupled reduced-complexity multiple signals classification(DRC MUSIC)algorithm is designed specifically.Simulation results demonstrate that:a)our proposed scheme can achieve underdetermined 2D DOA estimation just by the linear arrays;b)our designed DRC MUSIC algorithm has the good properties of high accuracy and low complexity;c)our proposed motion scheme with the DRC method has better universality in the motion direction.

COMPLEX NUMBER MODE APPROACH FOR REDUCING VIBRATION OF STRUCTURAL FLEXIBLE REDUNDANT ROBOT MANIPULATORS

A complex number mode analysis approach is proposed for vibration reducing of structural flexible redundant manipulators by utilizing self motion. In the proposed approach, the self motion is evaluated to nullify the modal exciting force of flexural motion, and the approach can be freely used when the degree of freedom of flexural motion is much greater than the available degree of reundancy. The availability and effectiveness of the proposed approach are demonstrated through numerical simulation with a four link spatial robotic manipulator possessing an end flexible link.

One inorganic–organic hybrid derived from reduced molybdophosphate and trinuclear cadmium(II) fragment

One new polyoxometalate （POM）-based inorganic-organic hybrid [Cdn3~HPO4）（Hbpp）（H20）2]{CdII[P4_ Mo6028H3.s（OH）312}.（H4tpb）.7H20 （1） （bpp = 1,3-bis-（4-pyridyl）propane, tpb = 1,2,4,5-tetra（4-pyridyl）- benzene） constructed from reduced molybdophosphate [P4Mo6028H3.5（OH）3]s＇5- （P4Mo6）, trinuclear Cdn-phosphate-Hbpp fragment and protonated tpb has been hydrothermally synthesized and structurally characterized by IR, elemental analyses and single crystal X-ray diffraction. The complex 1 crystallizes in the monoclinic system with the space group P21]c and cell parameters of a=15.672（12）A, b=23.839（19）A, c=27.654（2）,~, fl=115.850（10）~, V=9297.9（12） ~3, Z=4, R1 ~0.0534 and wR2 ~0.1135. In complex 1, the P4Mo6 units are bridged by CdII ions to form the classic sandwich-type [Cd（P4Mo6）2] dimers, which are further connected into a two dimensional network via the trinuclear Cdn subunits. The tpb is synthesized in situ from the bpp ligands and connects the adjacent 2D layers into a 3D supramolecular framework through hydrogen bonding interactions. The electrochemical and fluorescent properties of complex 1 have been investigated.