[Objective]Aiming at the problem of the identification of whether the bicycle controller is riding or pushing in urban road traffic,it is convenient for the smart car to identify the bicycle controller's intention to cross the street accurately and prevent possible collisions in advance due to the bicycle crossing the street too fast.Concurrently,to meet the needs of local college students for measuring bicycle riding/pushing posture at a low cost,a bicycle controller riding/pushing posture parameter measurement experiment was completed.[Methods]This study is based on bicycle controller riding/pushing physical experiments.Three representative experimental volunteers(a small-statured female,a medium-statured male,and a large-statured male)were selected according to the Chinese adult body dimensions.Three types of bicycles were selected based on appearance and their daily use(commuter,mountain,and road bikes).Reflective stickers were attached to some joints of the controller to facilitate subsequent measurements of posture parameters.This study proposes two measurement methods,manual and software-assisted.Manual measurement involves marking the position of the reflective sticker,connecting the associated marked points,and,subsequently,using a protractor to measure the required angle.Software-assisted measurement relies on the Simi Motion software.The recorded video was imported into the software to automatically read the controller's posture angle.Seven posture parameters of the bicycle controller were obtained through the measurement methods:back angle,upper arm elevation angle,elbow bending angle,left/right thigh elevation angle,and knee bending angle.[Results]The statistical analysis using the Mann-Whitney U test method showed that the back and thigh elevation angles are the main characteristic parameters that distinguish the riding/pushing postures.When the back angle α>12° and the thigh elevation angle θ≤60°,riding was considered.When the back angle of the controller α≤12° and the thigh elevation angle θ>60°,pushing was considered.On this basis,a method for determining the riding/pushing posture is proposed.The results of 464 real photos showed that 90.3%of the riding/pushing posture could be accurately identified using a single image,showcasing the effectiveness of the proposed method.[Conclusions]This study proposes two methods that can measure seven angle parameters:back angle,upper arm elevation angle,elbow bending angle,left/right thigh elevation angle,and left/right knee bending angle,thus making it easier for school students to use simple materials.It can complete the measurement of posture parameters of riding/pushing bicycles.A riding/pushing posture experiment was performed to analyze the significant differences between the angle parameters.Evidently,the back angle,upper arm elevation angle,thigh elevation angle,and knee bending angle of the riding/pushing controller were significantly different,and the back and upper arm angles were significantly different.A significant correlation exists among the elevation angle,thigh elevation angle,and knee bending angle;thus,the riding/pushing posture can be identified based on the controller's back angle and thigh elevation angle.A posture recognition method is proposed,and the accuracy of identifying riding/pushing posture based on a picture reaches 90.3%.The posture parameter measurement method proposed in this study primarily serves scientific research and teaching and can provide a low-cost solution for measuring bicycle control and riding postures.
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