Design Consideration for Precise Cable Drive

2011 ◽  
Vol 305 ◽  
pp. 37-41 ◽  
Author(s):  
Ya Fei Lu ◽  
Da Peng Fan ◽  
De Jun Sheng ◽  
Zhi Yong Zhang

A brief overview of previously built Electro-Optical Tracking system reveals a trend toward smaller, more agile systems. Steel cable drive technology is an alternative to gearbox, belt and pulleys, chains and sprocket and other currently available transmission for several significant advantages, which includes backlash free, high stiffness, high efficiency, no lubrication etc.. As a new type of drive form, there were several key tradeoffs for the cable drive application, which will be developed and subjected in detail in this paper. Firstly Transmission principle and properties of cable drive is studied. Secondly, related design considerations of cable drive will be implemented and researched in detail, including the cable selection and capstan design, cable-groove matching strategy and cable tensioning design. Finally, actual application example of precise steel cable drive is presented for an Electro-Optical tracking gimbals, and performances tested validate the significant advantages of precise cable drive technology.

2014 ◽  
Vol 621 ◽  
pp. 323-330
Author(s):  
Wei Dong Tang ◽  
Qing Kun Zhou ◽  
Da Peng Fan ◽  
Fei Tuan Xiong ◽  
Nian Zhong Xia

Precise cable drive has been developed as a new-style transmission element that has the advantages of low backlash, high stiffness, high efficiency, no friction and no lubrication, and is widely used in electro-optical tracking system. A precise cable drive mechanism is designed in this paper. Its torque output is greater than 50Nm and precision is less than 0.1mrad. Size of the cable is selected base on the maximum load of the cable evaluated in the process of the reciprocating motion. In order to improve the driving capacity, design the cable-groove match strategy with the non-intervene cable wrapping method. A figure eight pattern wrapped method and screw pitch of the cable wrapped line is designed. The influence of the contact angle on the preload force and the influence of the preload force on the backlash are simulated by the software Matlab when the mechanism driving the maximum load. At last magnitude of the contact angle and the preload force is confirmed.


2012 ◽  
Vol 522 ◽  
pp. 332-336 ◽  
Author(s):  
Ya Fei Lu ◽  
Mo Hei ◽  
Zhi Yong Zhang ◽  
Da Peng Fan

Precise cable drive has been developed as an alternative transmission element to gearbox, belt and pulleys, chains and sprocket in Electro-Optical Tracking system. Precise cable drive has several significant advantages including backlash free, high stiffness, high efficiency, no lubrication etc. This paper develops analytical methods to predict the transverse oscillation frequency of precise cable drive to enable designers to better assess dynamic performance in the design study phase. Theoretical formulation of transverse oscillation equation for precise cable drive is carried out based on Hamiltons principle taking into account flexural rigidity of cable. Furthermore, the transverse oscillation frequency is obtained from the transverse oscillation equation assuming small and linear vibration. Parametric studies are conducted to evaluate the relationship between the oscillation properties and cable drive parameters.


2014 ◽  
Vol 621 ◽  
pp. 195-200
Author(s):  
Ya Fei Lu ◽  
Da Peng Fan ◽  
Qing Yang Chen ◽  
Xin Xie

Precise cable drive has been developed as an alternative transmission element to gearbox, belt and pulleys, chains and sprocket in Electro-Optical Tracking system. Precise cable drive has several significant advantages including backlash free, high stiffness, high efficiency, no lubrication etc.. This paper develops analytical methods to predict the Torsional Vibration of precise cable drive to enable designers to better assess dynamic performance in the design study phase. Theoretical formulation of transmission stiffness for precise cable drive is carried out, the dynamic equation of cable drive system is deduced and inherent frequency is obtained. Parametric studies are conducted to evaluate the relationship between the inherent frequency and cable drive parameters.


Author(s):  
Yafei Lu ◽  
Dapeng Fan

Precise cable drive has been developed as an alternative transmission element to gears, belts and pulleys, chains and sprockets in electro-optical tracking system. The analytical method is developed to predict the transmission backlash of precise cable drive to enable designers to better assess the precision performance in the design study phase. Slip angle of precise cable drive is studied, and the effect of the rotational velocity and inertia of cable on the force equilibrium of contact region is considered. The deformation of cable in slip region and free region is calculated respectively and theoretical formulation of transmission backlash for precise cable drive system is carried out. Parametric sensitivity is investigated to evaluate the relationship between the transmission backlash and precise cable drive parameters including preload tension, load tension, friction coefficient, center distance and output drum radius. Experimental setup is built and the transmission backlash is tested. Effect of preload tension on the transmission backlash is tested. Results show that the experimental value and the theoretical curve of the transmission backlash fit well, which validates the theoretical method developed in this article.


2021 ◽  
Vol 11 (9) ◽  
pp. 3947
Author(s):  
Marco Farronato ◽  
Gianluca M. Tartaglia ◽  
Cinzia Maspero ◽  
Luigi M. Gallo ◽  
Vera Colombo

Clinical use of portable optical tracking system in dentistry could improve the analysis of mandibular movements for diagnostic and therapeutic purposes. A new workflow for the acquisition of mandibular kinematics was developed. Reproducibility of measurements was tested in vitro and intra- and inter-rater repeatability were assessed in vivo in healthy volunteers. Prescribed repeated movements (n = 10) in three perpendicular directions of the tracking-device coordinate system were performed. Measurement error and coefficient of variation (CV) among repetitions were determined. Mandibular kinematics of maximum opening, left and right laterality, protrusion and retrusion of five healthy subjects were recorded in separate sessions by three different operators. Obtained records were blindly examined by three observers. Intraclass correlation coefficient (ICC) was calculated to estimate inter-rater and intra-rater reliability. Maximum in vitro measurement error was 0.54 mm and CV = 0.02. Overall, excellent intra-rater reliability (ICC > 0.90) for each variable, general excellent intra-rater reliability (ICC = 1.00) for all variables, and good reliability (ICC > 0.75) for inter-rater tests were obtained. A lower score was obtained for retrusion with “moderate reliability” (ICC = 0.557) in the inter-rater tests. Excellent repeatability and reliability in optical tracking of primary movements were observed using the tested portable tracking device and the developed workflow.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2528
Author(s):  
Songlin Bi ◽  
Yonggang Gu ◽  
Jiaqi Zou ◽  
Lianpo Wang ◽  
Chao Zhai ◽  
...  

A high precision optical tracking system (OTS) based on near infrared (NIR) trinocular stereo vision (TSV) is presented in this paper. Compared with the traditional OTS on the basis of binocular stereo vision (BSV), hardware and software are improved. In the hardware aspect, a NIR TSV platform is built, and a new active tool is designed. Imaging markers of the tool are uniform and complete with large measurement angle (>60°). In the software aspect, the deployment of extra camera brings high computational complexity. To reduce the computational burden, a fast nearest neighbor feature point extraction algorithm (FNNF) is proposed. The proposed method increases the speed of feature points extraction by hundreds of times over the traditional pixel-by-pixel searching method. The modified NIR multi-camera calibration method and 3D reconstruction algorithm further improve the tracking accuracy. Experimental results show that the calibration accuracy of the NIR camera can reach 0.02%, positioning accuracy of markers can reach 0.0240 mm, and dynamic tracking accuracy can reach 0.0938 mm. OTS can be adopted in high-precision dynamic tracking.


2020 ◽  
Vol 31 (01) ◽  
pp. 040-049 ◽  
Author(s):  
Robert W. Koch ◽  
Hasan Saleh ◽  
Paula Folkeard ◽  
Sheila Moodie ◽  
Conner Janeteas ◽  
...  

AbstractProbe-tube placement is a necessary step in hearing aid verification which needs ample hands-on experience and confidence before performing in clinic. To improve the methods of training in probe-tube placement, a manikin-based training simulator was developed consisting of a 3D-printed head, a flexible silicone ear, and a mounted optical tracking system. The system is designed to provide feedback to the user on the depth and orientation of the probe tube, and the time required to finish the task. Although a previous validation study was performed to determine its realism and teachability with experts, further validation is required before implementation into educational settings.This study aimed to examine the skill transference of a newly updated probe-tube placement training simulator to determine if skills learned on this simulator successfully translate to clinical scenarios.All participants underwent a pretest in which they were evaluated while performing a probe-tube placement and real-ear-to-coupler difference (RECD) measurement on a volunteer. Participants were randomized into one of two groups: the simulator group or the control group. During a two-week training period, all participants practiced their probe-tube placement according to their randomly assigned group. After two weeks, each participant completed a probe-tube placement on the same volunteer as a posttest scenario.Twenty-five novice graduate-level student clinicians.Participants completed a self-efficacy questionnaire and an expert observer completed a questionnaire evaluating each participant’s performance during the pre- and posttest sessions. RECD measurements were taken after placing the probe tube and foam tip in the volunteer’s ear. Questionnaire results were analyzed through nonparametric t-tests and analysis of variance, whereas RECD results were analyzed using a nonlinear mixed model method.Results suggested students in the simulator group were less likely to contact the tympanic membrane when placing a probe tube, appeared more confident, and had better use of the occluding foam tip, resulting in more improved RECD measurements.The improved outcomes for trainees in the simulator group suggest that supplementing traditional training with the simulator provides useful benefits for the trainees, thereby encouraging its usage and implementation in educational settings.


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