A subject who wears a suitable robotic device will be able to walk in complex environments with the aid of environmental recognition schemes that provide reliable prior information of the human motion intent.Researche...A subject who wears a suitable robotic device will be able to walk in complex environments with the aid of environmental recognition schemes that provide reliable prior information of the human motion intent.Researchers have utilized 1 D laser signals and 2 D depth images to classify environments,but those approaches can face the problems of self-occlusion.In comparison,3 D point cloud is more appropriate for depicting the environments.This paper proposes a directional PointNet to directly classify the 3 D point cloud.First,an inertial measurement unit(IMU)is used to offset the orientation of point cloud.Then the directional PointNet can accurately classify the daily commuted terrains,including level ground,climbing up stairways,and walking down stairs.A classification accuracy of 98%has been achieved in tests.Moreover,the directional PointNet is more efficient than the previously used PointNet because the T-net,which is utilized to estimate the transformation of the point cloud,is not used in the present approach,and the length of the global feature is optimized.The experimental results demonstrate that the directional PointNet can classify the environments in robust and efficient manner.展开更多
Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in th...Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in this era of technology.Instruction-assisted 3D technology can display stereo graphics and promote students'understanding of the geometrical structure and characteristics of graphics.Spatial ability includes several aspects.Few software programs are available for training different aspects of spatial ability for senior high school students.This study aims to explore an effective method for training the spatial ability for senior high school students,and to promote the development of students'independent inquiry ability.Methods First,an inquiry design strategy to improve the spatial ability of students is proposed.Based on this strategy,unity3D was used to develop a 3D inquiry environment that can use leap motion to complete a gesture interaction.Finally,researchers carried out experience-based activities and issued user experience questionnaires to participants to verify the application effect of the spatial ability inquiry environment and used interviews to understand the user experience of participants exploring the leap motion device in a 3D inquiry environment.Results 32 learners participated in the experiment.learners have a high score for perceived usefulness and willingness to use.Compared with the perceived ease of use and perceived usefulness,the average score of the application effect is relatively low.In terms of willingness to use,most of the learners expressed their willingness to use a similar inquiry environment for spatial ability training in the future.Conclusions The spatial ability inquiry environment can help learners better understand different concepts.The users showed a strong willingness to continue using the device.The device also updates the teaching concept to a certain extent and emphasizes the dominant position of a student.展开更多
文摘A subject who wears a suitable robotic device will be able to walk in complex environments with the aid of environmental recognition schemes that provide reliable prior information of the human motion intent.Researchers have utilized 1 D laser signals and 2 D depth images to classify environments,but those approaches can face the problems of self-occlusion.In comparison,3 D point cloud is more appropriate for depicting the environments.This paper proposes a directional PointNet to directly classify the 3 D point cloud.First,an inertial measurement unit(IMU)is used to offset the orientation of point cloud.Then the directional PointNet can accurately classify the daily commuted terrains,including level ground,climbing up stairways,and walking down stairs.A classification accuracy of 98%has been achieved in tests.Moreover,the directional PointNet is more efficient than the previously used PointNet because the T-net,which is utilized to estimate the transformation of the point cloud,is not used in the present approach,and the length of the global feature is optimized.The experimental results demonstrate that the directional PointNet can classify the environments in robust and efficient manner.
基金the National Key Research and Development Program of China(2018YFB1004903)the Key Discipline Cultivation Program of Zhejiang Province(18JYXK018).
文摘Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in this era of technology.Instruction-assisted 3D technology can display stereo graphics and promote students'understanding of the geometrical structure and characteristics of graphics.Spatial ability includes several aspects.Few software programs are available for training different aspects of spatial ability for senior high school students.This study aims to explore an effective method for training the spatial ability for senior high school students,and to promote the development of students'independent inquiry ability.Methods First,an inquiry design strategy to improve the spatial ability of students is proposed.Based on this strategy,unity3D was used to develop a 3D inquiry environment that can use leap motion to complete a gesture interaction.Finally,researchers carried out experience-based activities and issued user experience questionnaires to participants to verify the application effect of the spatial ability inquiry environment and used interviews to understand the user experience of participants exploring the leap motion device in a 3D inquiry environment.Results 32 learners participated in the experiment.learners have a high score for perceived usefulness and willingness to use.Compared with the perceived ease of use and perceived usefulness,the average score of the application effect is relatively low.In terms of willingness to use,most of the learners expressed their willingness to use a similar inquiry environment for spatial ability training in the future.Conclusions The spatial ability inquiry environment can help learners better understand different concepts.The users showed a strong willingness to continue using the device.The device also updates the teaching concept to a certain extent and emphasizes the dominant position of a student.
