基于视觉测量的智能轮椅床自动对接

为了提高智能轮椅床系统对接的自主性,提出了一种基于视觉测量的自动对接架构。轮椅床对接过程分为远程导引阶段和近程对接阶段。在远程导引阶段,室内天花板视觉系统采集并识别轮椅上的新型人工标志,利用卡尔曼滤波(KF)的跟踪检测路标特征,继而采用P3P的视觉定位方法确定路标与相机的相对位姿,根据轮椅坐标系与远程阶段的世界坐标系的变换关系确定轮椅的姿态。在近程对接阶段,车载单目视觉系统采集对接目标的引导标志,利用引导标志的角点估计轮椅与床的相对位姿,最后根据实时的视觉反馈实现床椅的自动对接。多次实验结果表明所提出的视觉对接方法具有可行性和有效性。

Visual measurement based automatic docking for intelligent wheelchair/bed

To improve the autonomy of intelligent wheelchair/bed system (IWBS) docking, a visual measurement based framework for automatic docking is proposed. The docking process of IWBS is divided into remote guidance stage and short range visual docking stage. In the long range guidance stage, a new artificial landmark on the wheelchair is collected and identified by the visual system on the ceiling. Afterwards, the artificial landmark is detected using a tracking method based on Kalman Filter (KF). The relative pose between the artificial landmark and the camera is then determined according to the P3P (perspective three point, P3P) visual positioning method. Using the transformation between the wheelchair coordinate system and the world coordinate of the remote guidance stage, the position and orientation of wheelchair are then determined. In short range docking stage, the guiding landmark of the docking target is collected using an on board monocular vision system. The feature of the guiding landmark is used to estimate the relative pose between the wheelchair and the bed. Finally, the automatic docking of IWBS is realized according to the visual feedback in real time. Numerous experiments are carried and experimental results show that the visual docking methods proposed in this work is feasible and effective.