立体视觉测量中的图像匹配策略研究

立体视觉测量广泛应用于机器人导向和各种柔性制造系统中 ,其中图像特征的准确匹配始终是一个难题。推导了共极性线方程 ,采取相关匹配和特征匹配相结合的方法来提高图像匹配的速度和精度 ,利用建模估计得到匹配像点的精确坐标 ,使三维测量精度达到目标距离的 1/10 0 0 0左右     

Magnetoresistance effect in vertical NiFe/graphene/NiFe junctions

For convenient and efficient verification of the magnetoresistance effect in graphene spintronic devices, vertical magnetic junctions with monolayer graphene sandwiched between two NiFe electrodes are fabricated by a relatively simple way of transferring CVD graphene onto the bottom ferromagnetic stripes. The anisotropic magnetoresistance contribution is excluded by the experimental result of magnetoresistance (MR) ratio dependence on the magnetic field direction. The spin-dependent transport measurement reveals two distinct resistance states switching under an in-plane sweeping magnetic field. A magnetoresistance ratio of about 0.17 % is obtained at room temperature and it shows a typical monotonic downward trend with the bias current increasing. This bias dependence of MR further verifies that the spin transport signal in our device is not from the anisotropic magnetoresistance. Meanwhile, the I—V curve is found to manifest a linear behavior, which demonstrates the Ohmic contacts at the interface and the metallic transport characteristic of vertical graphene junction.