激光陀螺的物理原理

通过对激光陀螺的物理原理的介绍，阐明了物理学与现代科技的联系。     

Quantitative assessment of developmental levels in overarm throwing using wearable inertial sensing technology

Motor proficiency in childhood has been recently recognised as a public health determinant, having a potential impact on the physical activity level and possible sedentary behaviour of the child later in life. Among fundamental motor skills, ballistic skills assessment based on in-field quantitative observations is progressively needed in the motor development community. The aim of this study was to propose an in-field quantitative approach to identify different developmental levels in overarm throwing. Fifty-eight children aged 5–10 years performed an overarm throwing task while wearing three inertial sensors located at the wrist, trunk and pelvis level and were then categorised using a developmental sequence of overarm throwing. A set of biomechanical parameters were defined and analysed using multivariate statistics to evaluate whether they can be used as developmental indicators. Trunk and pelvis angular velocities and time durations before the ball release showed increasing/decreasing trends with increasing developmental level. Significant differences between developmental level pairs were observed for selected biomechanical parameters. The results support the suitability and feasibility of objective developmental measures in ecological learning contexts, suggesting their potential supportiveness to motor learning experiences in educational and youth sports training settings.     

A survey of sensor devices: use in sports biomechanics

This paper examines the use of sensor devices in sports biomechanics, focusing on current frequency of use of Electromyography (EMG) device preferences. Researchers in the International Society of Biomechanics in Sports were invited to participate in an online survey. Responses on multiple sensor devices highlighting frequency of use, device features and improvements researchers sought in acquisition and analysis methods were obtained via an online questionnaire. Results of the investigation showed that the force platform is the most frequently used device, with inertial measurement units and EMG devices growing in popularity. Wireless functionality and ease of use for both the participant and the practitioner proved to be important features. The main findings of the survey demonstrated need for a simple, low power, multi-channel device which incorporates the various sensors into one single device. Biomechanists showed they were looking for more availability of wireless sensor devices with acquisition and analysis features. The study found there is a need to develop software analysis tools to accompany the multi-channel device, providing all the basic functions while maintaining compatibility with existing systems.     

最优化模式下高校竞技陀螺运动特色教材开发研究

在查阅大量有关最优化教学模式的文献资料的基础之上,总结出陀螺运动课程体系最优化的教学模式,并在此基础之上开发出相应的竞技陀螺运动特色教材,从而为陀螺运动教学质量的提高、陀螺运动在高校的进一步发展乃至高校民族传统体育课程体系与教材体系构建提供理论与实践参考.     

陀螺技术分类与动作结构分析

结合十多年从事民族传统体育陀螺项目教学、训练及竞赛的实践经验,对民族传统体育陀螺项目的技术进行了分类,就陀螺技术的特点、技术动作结构等进行了分析。     

Determining motions with an IMU during level walking and slope and stair walking

ABSTRACT

This study investigated whether using an inertial measurement unit (IMU) can identify different walking conditions, including level walking (LW), descent (DC) and ascent (AC) slope walking as well as downstairs (DS) and upstairs (US) walking. Thirty healthy participants performed walking under five conditions. The IMU was stabilised on the exterior of the left shoe. The data from IMU were used to establish a customised prediction model by cut point and a prediction model by using deep learning method. The accuracy of both prediction models was evaluated. The customised prediction model combining the angular velocity of dorsi–plantar flexion in the heel-strike (HS) and toe-off (TO) phases can distinctly determine real conditions during DC and AC slope, DS, and LW (accuracy: 86.7–96.7%) except for US walking (accuracy: 60.0%). The prediction model established by deep learning using the data of three-axis acceleration and three-axis gyroscopes can also distinctly identify DS, US, and LW with 90.2–90.7% accuracy and 84.8% and 82.4% accuracy for DC and AC slope walking, respectively. In conclusion, inertial measurement units can be used to identify walking patterns under different conditions such as slopes and stairs with customised prediction model and deep learning prediction model.     

激光发展现状与应用前景分析

自1960年第一台激光器发明以来,经过几十年的发展,激光技术的研究取得了飞越性的发展并广泛应用于人们生活的各个领域。本文主要介绍了激光的应用领域以及一些处于研究前沿领域的技术。     

The validation and application of Inertial Measurement Units to springboard diving

Inertial Measurement Units (IMUs) may offer an ecologically valid, reliable, and practical method for biomechanical performance analysis. With such potential in mind, Part 1 of this study examined the accuracy of IMUs gyroscopes with an optical system (Cortex 3.3). A calibration formula standardised the IMUs angular velocity output with the optical system. The percentage differences between the two measures = 0.5% (p < 0.05), suggest IMU’s efficacy for application. In Part 2, the aim was to examine and understand how dive flight angular velocity time series plots change and increase according to dive degree of difficulty. With IMUs attached to three competitive divers performing forward somersault dives, dive flight kinematics were assessed. Biomechanically, a 4½ tuck somersault dive differed to lower degree of difficulty dives in terms of: (1) a rotational delay immediately after takeoff (to gain greater vertical translation); (2) increased total time of flight; (3) greater muscle effort to resist increased centrifugal forces produced by the increased angular velocity (1,090 °/s); and (4) greater eccentric control during deceleration allow a safe and vertical entry into the water. IMUs can be effectively utilised and integrated into contexts such as springboard diving for performance analysis and optimisation purposes.     

基于GPS测姿和陀螺仪的角度融合定位方法研究

针对城市峡谷等遮挡严重场景下GPS定位精度严重下降问题,提出一种基于GPS测向与陀螺仪角度测量的融合定位方法。该方法通过改进传统的角度测量,利用陀螺仪短时内相对测量精度高的特点,采用卡尔曼滤波,以陀螺仪的相对角度修正GPS测向的绝对角度,再利用GPS/INS组合导航算法进行定位,使定位结果精度更高、更稳定。对提出的方法进行模拟仿真以及车载实验,实验结果表明：通过角度融合后的定位拥有更高的定位精度和定位稳定性,在复杂环境下效果很好,提高了定位可靠性。     

惯性陀螺方法与基于标志点虚拟陀螺方法在网球发球中上臂转速测量上的应用

目的:将惯性陀螺方法和基于标志点虚拟陀螺(a Marker-Based Virtual Gyroscope简称MBVG)方法用于网球发球时上臂内转动动作的监测,并对监测结果同视频拍摄方法研究结果进行比较。方法:惯性陀螺方法利用上臂和胸部两个陀螺对网球发球中上臂的转动进行捕捉。MBVG方法根据Vicon光学动作捕捉系统来设置标志点,利用标志点轨迹建立一种基于向量的方法,并利用几何方法确定转动关系。结果:(1)惯性陀螺方法与视频拍摄方法的结果在规范化时间的0.2~1区间段一致性很好,表明此方法在测量上臂内转动上是有效的;(2)MBVG方法能够用于陀螺超量程的情况,其数据能够反映真实的发球动作;(3)3种方法测得的网球发球数据在特征上彼此能够很好的吻合。结论:惯性陀螺方法与基于标志点虚拟陀螺方法能够有效地用于网球发球评估。