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91.
92.
The occurrence of geometric orientation illusions and the perception of ambiguous figures were analyzed in 24 subjects during static body tilt relative to gravity on Earth. Results showed that illusions such as the Rock's diamond/square, the Ponzo illusion, and orientation contrast illusions occurred less frequently, and that depth reversal of ambiguous figures took more time when subjects were lying on their side or supine compared to upright, thus suggesting that the gravitational reference plays a significant role in these “visual” illusions. The structure of images, our representation of the environment, and orientation relative to gravity are all integral parts in interpreting visual images. In a weightless environment where no gravitational reference can be used, it is expected that similar alterations in visual perception will occur. 相似文献
93.
Chunhui Wang Yu Tian Shanguang Chen Zhiqiang Tian Ting Jiang Feng Du 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
Manually controlled rendezvous and docking (manual RVD) is a challenging space task for astronauts. This study aims to identify spatial abilities that are critical for accomplishing manual RVD. Based on task analysis, spatial abilities were deduced to be critical for accomplishing manual RVD. 15 Male participants performed manual RVD task simulations and spatial ability tests (the object-manipulation spatial ability and spatial orientation ability). Participants’ performance in the test of visualization of viewpoints (which measures the spatial orientation ability) was found to be significantly correlated with their manual RVD performance, indicating that the spatial orientation ability in the sense of perspective taking is particularly important for accomplishing manual RVD. 相似文献
94.
《中国航空学报》2023,36(3):220-240
Blade-health monitoring is intensely required for turbomachinery because of the high failure risk of rotating blades. Blade-Tip Timing (BTT) is considered as the most promising technique for operational blade-vibration monitoring, which obtains the parameters that characterize the blade condition from recorded signals. However, its application is hindered by severe undersampling and stringent probe layouts. An inappropriate probe layout can make most of the existing methods invalid or inaccurate. Additionally, a general conflict arises between the allowed and required layouts because of arrangement restrictions. For the sake of economy and safety, parameter identification based on fewer probes has been preferred by users. In this work, a spatial-transformation-based method for parameter identification is proposed based on a single-probe BTT measurement. To present the general Sampling-Aliasing Frequency (SAFE) map definition, the traditional time–frequency analysis methods are extended to a time-sampling frequency. Then, a SAFE map is projected onto a parameter space using spatial transformation to extract the slope and intercept parameters, which can be physically interpreted as an engine order and a natural frequency using coordinate transformation. Finally, the effectiveness and robustness of the proposed method are verified by simulations and experiments under uniformly and nonuniformly variable speed conditions. 相似文献
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96.
雷达目标跟踪中的非线性滤波技术 总被引:6,自引:6,他引:0
对雷达目标跟踪中的9种非线性滤波技术进行了综述,介绍了其基本思想,分析了各方法的优缺点并进行了比较。 相似文献
97.
微絮凝变孔隙深层过滤处理低浊度废水研究 总被引:1,自引:0,他引:1
本文研究了微絮凝变孔隙深层过滤处理低浊度废水时,滤料粒径、絮凝剂种类、投加量、滤速等因素对过滤效果的影响。试验结果表明:在达到相同出水水质的情况下,由于变孔隙结构等原因,该系统具有用药量省、阻力损失小、出水量大及整床过滤效能好等优点。 相似文献
98.
针对在前馈/反馈混合控制中提高控制通道阻尼的问题,基于自适应滤波理论,提出适用于单输入单输出(SISO)和多输入多输出(MIMO)控制通道的时域自适应反馈主动阻尼设计方法。研究了自适应过程的理想期望信号的构造、SISO情况下闭环控制通道与反馈控制器同时进行自适应设计以及MIMO控制通道阻尼问题的简化与设计方法的拓展等问题;同时,基于某主动隔振试验平台的实测结果,对所有研究内容进行SIMULINK模型仿真。时域自适应反馈主动阻尼设计是高效的主动阻尼设计方法,并且为小阻尼动态系统的增阻设计提供了统一的方法框架。 相似文献
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100.
星敏感器姿态测量相对基准偏差在轨标校方法研究 《空间控制技术与应用》2017,43(6):1-7
摘要: 对航天器星敏感间姿态测量基准偏差在轨标校及性能评估问题进行研究.建立包含敏感器安装误差与测量误差的星敏感器模型,针对两种不同形式的安装误差模型,推导出相应的观测方程,基于卡尔曼滤波方法设计相对基准偏差估计器,并比较分析两种估计器实际应用特点.然后针对在轨实际应用,给出一种基于敏感器光轴夹角的标校性能评估方法,通过数学仿真验证星敏感器相对基准偏差的标校的有效性,并基于在轨数据的标校应用获取相对基准偏差在轨特性. 相似文献