高危作业现场环境复杂,危险系数高,容易发生跌倒事故,造成人员伤亡。为了检测工人跌倒行为,提出了一种基于Kinect传感器的人体跌倒检测方法。利用Kinect获取深度图像,提取关节点信息,通过计算关节点相对位置熵和速度的变化,判断人体是否发生跌倒。通过对比实验,确定了一组跌倒识别率最高的骨架关节点:头、双肩、双膝、中心点。实验数据表明该方法可以更快速准确地检测出跌倒行为。

An acoustic emission (AE) linear location system was proposed, which employed fiber Bragg gratings (FBGs) as AE sensors. It was demonstrated that the FBG wavelength could be modulated as the static case when the grating length was much shorter than the AE wavelength. In addition, an improved AE location method based on the Gabor wavelet transform (WT) and threshold analysis was represented. The method was testified through AE linear location experiments based on a tunable narrow-band laser interrogation system using ultra-short FBG sensors as AE sensors. Results of the experiments showed that 86% of the linear location errors were less than 10 mm.

与可见光图像相比，红外图像的分辨率较低，景物边缘较为粗糙，传统的自动调焦技术无法直接用于红外热成像系统。为了解决这一问题，采用基于红外图像边缘特性的自动对焦算法，建立快速有效的对焦评价函数，驱动高精度光机闭环控制单元，以实现快速、准确的红外自动对焦。系统包含数字处理单元和运动控制单元。其中数字图像处理单元主要进行红外数字图像的采集，利用Roberts梯度算子提取红外图像中的信息量，并统计边缘点数以评价图像的清晰度，实时计算序列红外图像中细节和信息量的变化量和趋势，从而提供运动控制单元所需的位置给定。运动控制单元则主要进行调焦电机的控制及驱动，完成自动聚焦的过程控制。最后，通过实验证明了该方案的有效性。