The spherical plain bearing test bench is a necessary detecting equipment in the research process of self?lubricating spherical plain bearings. The varying environmental temperatures cause the thermal deformation of t...The spherical plain bearing test bench is a necessary detecting equipment in the research process of self?lubricating spherical plain bearings. The varying environmental temperatures cause the thermal deformation of the wear?depth detecting system of bearing test benches and then a ect the accuracy of the wear?depth detecting data. However, few researches about the spherical plain bearing test benches can be found with the implementation of the detect?ing error compensation. Based on the self?made modular spherical plain bearing test bench, two main causes of ther?mal errors, the friction heat of bearings and the environmental temperature variation, are analysed. The thermal errors caused by the friction heat of bearings are calculated, and the thermal deformation of the wear?depth detecting sys?tem caused by the varying environmental temperatures is detected. In view of the above results, the environmental temperature variation is the main cause of the two error factors. When the environmental temperatures rise is 10.3 °C, the thermal deformation is approximately 0.01 mm. In addition, the comprehensive compensating model of the thermal error of the wear?depth detecting system is built by multiple linear regression(MLR) and time series analysis. Compared with the detecting data of the thermal errors, the comprehensive compensating model has higher fitting precision, and the maximum residual is only 1 μm. A comprehensive compensating model of the thermal error of the wear?depth detecting system is proposed, which provides a theoretical basis for the improvement of the real?time wear?depth detecting precision of the spherical plain bearing test bench.展开更多
基于多视点视频加深度(Multiview Video plus Depth,MVD)格式的三维视频能给用户提供多视角的沉浸式视觉体验.针对MVD视频流传输中彩色帧发生整帧丢失的情况,提出了一种结合视觉显著性的三维视频整帧丢失错误隐藏算法.先将丢失帧各区域...基于多视点视频加深度(Multiview Video plus Depth,MVD)格式的三维视频能给用户提供多视角的沉浸式视觉体验.针对MVD视频流传输中彩色帧发生整帧丢失的情况,提出了一种结合视觉显著性的三维视频整帧丢失错误隐藏算法.先将丢失帧各区域划分为三种不同的显著等级,然后对低、中、高显著区域,分别采用时域直接拷贝、时域和视点间像素自适应搜索法和新型的运动矢量补偿法进行恢复.相较于目前的对比算法,经提出算法重建后的丢失帧的峰值信噪比值(Peak Signal to Noise Ratio,PSNR)和结构相似度值(Structural Similarity Index Measure,SSIM)能分别提高0.99~2.61 dB和0.005~0.012,并且重建图像主观视觉质量更佳.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51405422)Hebei Provincial Natural Science Foundation of China(Grant No.E2015203113)Technological Innovation Fund of Aviation Industry of China(Grant No.2014E00468R)
文摘The spherical plain bearing test bench is a necessary detecting equipment in the research process of self?lubricating spherical plain bearings. The varying environmental temperatures cause the thermal deformation of the wear?depth detecting system of bearing test benches and then a ect the accuracy of the wear?depth detecting data. However, few researches about the spherical plain bearing test benches can be found with the implementation of the detect?ing error compensation. Based on the self?made modular spherical plain bearing test bench, two main causes of ther?mal errors, the friction heat of bearings and the environmental temperature variation, are analysed. The thermal errors caused by the friction heat of bearings are calculated, and the thermal deformation of the wear?depth detecting sys?tem caused by the varying environmental temperatures is detected. In view of the above results, the environmental temperature variation is the main cause of the two error factors. When the environmental temperatures rise is 10.3 °C, the thermal deformation is approximately 0.01 mm. In addition, the comprehensive compensating model of the thermal error of the wear?depth detecting system is built by multiple linear regression(MLR) and time series analysis. Compared with the detecting data of the thermal errors, the comprehensive compensating model has higher fitting precision, and the maximum residual is only 1 μm. A comprehensive compensating model of the thermal error of the wear?depth detecting system is proposed, which provides a theoretical basis for the improvement of the real?time wear?depth detecting precision of the spherical plain bearing test bench.
文摘基于多视点视频加深度(Multiview Video plus Depth,MVD)格式的三维视频能给用户提供多视角的沉浸式视觉体验.针对MVD视频流传输中彩色帧发生整帧丢失的情况,提出了一种结合视觉显著性的三维视频整帧丢失错误隐藏算法.先将丢失帧各区域划分为三种不同的显著等级,然后对低、中、高显著区域,分别采用时域直接拷贝、时域和视点间像素自适应搜索法和新型的运动矢量补偿法进行恢复.相较于目前的对比算法,经提出算法重建后的丢失帧的峰值信噪比值(Peak Signal to Noise Ratio,PSNR)和结构相似度值(Structural Similarity Index Measure,SSIM)能分别提高0.99~2.61 dB和0.005~0.012,并且重建图像主观视觉质量更佳.
