槽形轨井字形组合道岔的设计

应三亚市有轨电车线路所需研制了槽形轨井字形组合道岔。根据线路设置与行车条件,确定了槽形轨井字形组合道岔的平面布置形式。首先采用有限元方法对比73C1钢轨和105C1钢轨的受力和横向位移进行钢轨选型;然后将既有辙叉结构形式优化为钢轨焊接式辙叉;最后选取仿形断面钢轨,采用熔化极活性气体保护焊工艺焊接后进行了钢轨静弯强度试验。结果表明：无论是受力,还是横向位移,105C1钢轨均优于73C1钢轨,且105C1钢轨重心稳定,开槽位置较自由,焊接性能更好;与既有辙叉相比,采用钢轨焊接式辙叉,焊接接头数量减少1/2,降低了加工成本和开裂风险;采用熔化极活性气体保护焊工艺焊接后钢轨轨头和轨底的静弯强度满足规范要求,且焊接单个接头用时短。槽形轨井字形组合道岔已于2019年在三亚有轨电车示范线上应用,上道4年来线路运营状态良好。     

Range profile target recognition using sparse representation based on feature space

A novel method is presented to improve the recognition rate of warhead in this paper. Firstly, a tool for electromagnetic calculation, like CST Microwave Studio, is used to simulate the frequency response of the electromagnetic scattering. Secondly, the echo and further the range profile are acquired from the frequency response by further processing. Thirdly, a set of discriminative features is extracted from the range profiles of the target. Fourthly, these features are used to construct a dictionary for the sparse representation classifier. Finally, the sample of the target can be classified by solving the sparsest coefficients. Since the reconstruction result is determined by a linear combination of the training samples, this method has a good robustness for the variable features. By formulating the problem within a feature-based sparse representation framework, the presented method combines the discriminative features of each sample during the sparse recovery process rather than in a postprocessing manner. Moreover, based on the feature representation space rather than a single feature or image pixel, the constructed dictionary exhibits both strong expressive and discriminative powers that can enhance the classification performance of the test sample. A series of test results based on the simulated data demonstrates the effectiveness of our method.