Journal articles: 'Rotation accuracy'

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Foss, O. A., J. Klaksvik, P. Benum, and S. Anda. "Validation of the rotation ratios method." Acta Radiologica 48, no. 6 (July 2007): 658–64. http://dx.doi.org/10.1080/02841850701348705.

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Background: The rotation ratios method describes rotations between pairs of sequential pelvic radiographs. The method seems promising but has not been validated. Purpose: To validate the accuracy of the rotation ratios method. Material and Methods: Known pelvic rotations between 165 radiographs obtained from five skeletal pelvises in an experimental material were compared with the corresponding calculated rotations to describe the accuracy of the method. The results from a clinical material of 262 pelvic radiographs from 46 patients defined the ranges of rotational differences compared. Repeated analyses, both on the experimental and the clinical material, were performed using the selected reference points to describe the robustness and the repeatability of the method. Results: The reference points were easy to identify and barely influenced by pelvic rotations. The mean differences between calculated and real pelvic rotations were 0.0° (SD 0.6) for vertical rotations and 0.1° (SD 0.7) for transversal rotations in the experimental material. The intra- and interobserver repeatability of the method was good. Conclusion: The accuracy of the method was reasonably high, and the method may prove to be clinically useful.

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Green, Andrew, Samantha Kerr, Benita Olivier, Chloe Dafkin, and Warrick McKinon. "The trade-off between distance and accuracy in the rugby union place kick." Kinesiology 48, no. 2 (2016): 251–57. http://dx.doi.org/10.26582/k.48.2.4.

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Little attention has been given to the rotational kinematics of the rugby union place kicking performance, especially in a field setting. The place kick is a means to score points. By maximizing the distance and accuracy a kicker is able to achieve increases the number of point scoring opportunities available to a team. The hypothesis of this study was that there is a relationship between distance and accuracy and the rotational kinematics of place kicking performance of rugby players in the field setting. Twelve first-team university rugby players had their full body kinematics measured for five place kicks. Kick distance and accuracy were directly measured. The current study showed a positive correlation between torso (r=.76) and pelvis (r=.66) rotation with kick distance. Place kick distance (r=.24) or accuracy (r=.54) were not correlated to playing experience. Negative correlations between stance elbow flexion (r=-.78), torso rotation (r=-.74) and X-factor (r=-.79) with kick accuracy were noted. Place kick distance could potentially be maximized by improving torso and pelvic rotations. Place kick accuracy could be improved by full extension of the stance arm. The data suggests that larger torso rotations may promote kicking distance; however, they impede kicking accuracy.

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Liu, Yiqing, Wenzhi Zhao, Shuo Chen, and Tao Ye. "Mapping Crop Rotation by Using Deeply Synergistic Optical and SAR Time Series." Remote Sensing 13, no. 20 (October 17, 2021): 4160. http://dx.doi.org/10.3390/rs13204160.

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Crop rotations, the farming practice of growing crops in sequential seasons, occupy a core position in agriculture management, showing a key influence on food security and agro-ecosystem sustainability. Despite the improvement in accuracy of identifying mono-agricultural crop distribution, crop rotation patterns remain poorly mapped. In this study, a hybrid convolutional neural network (CNN) and long short-term memory (LSTM) architecture, namely crop rotation mapping (CRM), were proposed to synergize the synthetic aperture radar (SAR) and optical time series in a rotational mapping task. The proposed end-to-end architecture had reasonable accuracies (i.e., accuracy > 0.85) in mapping crop rotation, which outperformed other state-of-the-art non-deep or deep-learning solutions. For some confusing rotation types, such as fallow-single rice and crayfish-single rice, CRM showed substantial improvements from traditional methods. Furthermore, the deeply synergistic SAR-optical, time-series data, with a corresponding attention mechanism, were effective in extracting crop rotation features, with an overall gain of accuracy of four points compared with ablation models. Therefore, our proposed method added wisdom to dynamic crop rotation mapping and yields important information for the agro-ecosystem management of the study area.

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Danielsson, Per-Erik, and Magnus Hammerin. "High-accuracy rotation of images." CVGIP: Graphical Models and Image Processing 54, no. 4 (July 1992): 340–44. http://dx.doi.org/10.1016/1049-9652(92)90080-h.

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Lu, Feng, Hong Bo Shen, Xiao Fei Zhang, Li Xiu Zhang, Yu Hou Wu, and Ke Zhang. "Analysis of Spindle Rotary Precision Based on Two-Point Methods." Applied Mechanics and Materials 624 (August 2014): 327–31. http://dx.doi.org/10.4028/www.scientific.net/amm.624.327.

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Two-point method designed of the test system for application, the precision of the motorized spindle rotation was dynamic measurements. The system consists of standard bars, high-precision non-contact eddy current sensor. Analyzed by a mathematical model to establish error separation, measurement of two spindle rotation accuracy. The use of two isolated error method for processing the experimental data obtained spindle rotation accuracy at different speeds. Studies have shown that when the spindle speed of 10,000 rpm rotational error is small and tends to be more stable. Identify the factors that affect the accuracy of spindle rotation and summarized. Spindle rotation accuracy on-line monitoring and speed control provides an important theoretical, experimental basis.

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Sun, Yanhui, Junkang Guo, Jun Hong, and Guanghui Liu. "Modeling of rotation accuracy of multi-support rotating machinery considering geometric errors and part deformation." Assembly Automation 40, no. 5 (September 15, 2020): 665–73. http://dx.doi.org/10.1108/aa-07-2018-099.

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Purpose This paper aims to develop a theoretical method to analyze the rotation accuracy of rotating machinery with multi-support structures. The method effectively considers the geometric errors and assembly deformation of parts. Design/methodology/approach A method composed of matrix and FEA methods is proposed to do the analysis. The deviation propagation analysis results and external loads are set as boundary conditions of the model which is built with Timoshenko beam elements to calculate the spatial pose of the rotor. The calculation is performed repeatedly as the rotation angle increased to get the rotation trajectories of concerned nodes, and further evaluation is done to get the rotation accuracy. Additionally, to get more reliable results, the bearing motion errors and stiffness are analyzed by a static model considering manufacturing errors of parts. Findings The feasibility of the proposed method is verified through a case study of a high-precision spindle. The method reasonably predicts the rotation accuracy of the spindle. Originality/value For rotating machinery with multi-support structures, the paper proposes a modeling method to predict the rotation accuracy, simultaneously considering geometric errors and assembly deformation of parts. This would improve the accuracy of tolerance analysis.

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Jing, Zhengyao, Jie Li, Xi Zhang, Kaiqiang Feng, and Tao Zheng. "A Novel Rotation Scheme for MEMS IMU Error Mitigation Based on a Missile-Borne Rotation Semi-Strapdown Inertial Navigation System." Sensors 19, no. 7 (April 9, 2019): 1683. http://dx.doi.org/10.3390/s19071683.

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In previous research, a semi-strapdown inertial navigation system (SSINS), based on micro-electro-mechanical system (MEMS) sensors, was able to realize over-range measurement of the attitude information of high-rotation missiles by constructing a single axis “spin reduction” platform. However, the MEMS sensors in SSINS were corrupted by significant sensor errors. In order to further improve SSINS measurement accuracy, a rotational modulation technique has been introduced to compensate for sensor errors. The ideal modulation angular velocity is changed sharply to achieve a constant speed, while in practical applications, the angular rate of the rotating mechanism’s output needs to go through an acceleration-deceleration process. Furthermore, the stability of the modulation angular rate is difficult to achieve in a high-speed rotation environment. In this paper, a novel rotation scheme is proposed which can effectively suppress the residual error in the navigation coordinate system caused by the modulation angular rate error, including the acceleration-deceleration process and instability of angular rate. The experiment results show that the position and attitude accuracy of the new rotation scheme was increased by more than 56%. In addition, the proposed scheme is applicable to navigation accuracy improvement under various dynamic conditions.

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Zhang, H., L. Wang, TX Song, and K. Li. "Error analysis and compensation for dual-axis inertial navigation system with horizontal rotation modulation." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 1 (February 13, 2018): 313–22. http://dx.doi.org/10.1177/0954406218756940.

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Rotational inertial navigation system can significantly improve the navigation accuracy by rotating the inertial measurement unit about gimbals periodically. The precise calibration for installation errors and scale factor errors in rotational inertial navigation system can contribute to better navigation performance further. Especially in application requiring excellent azimuth precision, the horizontal rotation modulation will be badly required to modulate the vertical sensors’ errors as periodic variation, which can make inhibiting effect on the navigation errors. However, it also enlarges the impact of specific errors, which contains gyro’s scale factor error and the installation errors of inertial components. To meet the requirement of navigation precision, this paper has made error analysis and established mathematical model for a proposed horizontal rotation modulation in dual-axis rotational inertial navigation system. The crucial error parameters can be calibrated based on the measurements of attitude and velocity output without additional equipment. The results of experiment performed in an actual system demonstrate that navigation accuracy has been improved significantly, fully illustrating the significance and necessity of the calibration for specific errors in the horizontal rotation modulation.

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Liu, Yan, Zhendong Ge, Yingtao Yuan, Xin Su, Xiang Guo, Tao Suo, and Qifeng Yu. "Study of the Error Caused by Camera Movement for the Stereo-Vision System." Applied Sciences 11, no. 20 (October 9, 2021): 9384. http://dx.doi.org/10.3390/app11209384.

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The stereo-vision system plays an increasingly important role in various fields of research and applications. However, inevitable slight movements of cameras under harsh working conditions can significantly influence the 3D measurement accuracy. This paper focuses on the effect of camera movements on the stereo-vision 3D measurement. The camera movements are divided into four categories, viz., identical translations and rotations, relative translation and rotation. The error models of 3D coordinate and distance measurement are established. Experiments were performed to validate the mathematical models. The results show that the 3D coordinate error caused by identical translations increases linearly with the change in the positions of both cameras, but the distance measurement is not affected. For identical rotations, the 3D coordinate error introduced only in the rotating plane is proportional to the rotation angle within 10° while the distance error is zero. For relative translation, both coordinate and distance errors keep linearly increasing with the change in the relative positions. For relative rotation, the relationship between 3D coordinate error and rotation angle can be described as the nonlinear trend similar to a sine-cosine curve. The impact of the relative rotation angle on distance measurement accuracy does not increase monotonically. The relative rotation is the main factor compared to other cases. Even for the occurrence of a rotation angle of 10°, the resultant maximum coordinate error is up to 2000 mm, and the distance error reaches 220%. The results presented are recommended as practice guidelines to reduce the measurement errors.

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Iosif, Panagiotis, and Nikolaos Stergioulas. "Differentially Rotating Relativistic Stars beyond the J-Constant Law." Physical Sciences Forum 2, no. 1 (February 22, 2021): 62. http://dx.doi.org/10.3390/ecu2021-09312.

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The merger of a binary neutron star (BNS) system can lead to different final states depending on the total mass of the binary system and the equation of state (EOS). One of the possible outcomes of the merger is a long-lived (lifetime > 10 ms), compact and differentially rotating remnant. The Komatsu, Eriguchi and Hachisu (1989) differential rotation law (KEH) has been used almost exclusively in the literature to describe such configurations, despite the tension with corresponding rotational profiles reported from numerical simulations. New rotation laws suggested by Uryu et al. (2017) aspire to ease this tension and provide more realistic choices to describe the rotational profiles of BNS merger remnants. We recently started constructing equilibrium models with one of the new rotation laws proposed and comparing their physical properties to the KEH rotation law counterpart models. In addition, building on earlier work, the accuracy of the IWM-CFC conformal flatness approximation with the new differential rotation law was confirmed.

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Chen, Dongju, You Zhao, and Jingfang Liu. "Characterization and Evaluation of Rotation Accuracy of Hydrostatic Spindle under the Influence of Unbalance." Shock and Vibration 2020 (March 24, 2020): 1–16. http://dx.doi.org/10.1155/2020/5181453.

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The paper studies the characterization and evaluation technology of rotation accuracy of hydrostatic spindle under the influence of unbalance. The dynamic model of the motion error of the hydrostatic spindle is established based on the dynamic parameters. The variation law of motion error of spindle rotor is analyzed under the unbalanced mass. The paper finds that with the increase of the spindle speed, the amplitude of the spindle error motion will increase, and the inclination angle θ error is more sensitive to the change in the rotational speed. In the total synthesis accuracy, the proportion of synchronization error decreases with the increase of the rotational speed. Finally, the least squares evaluation algorithm is used to evaluate the rotation error of the hydrostatic spindle, and a method for evaluating the rotation accuracy of the hydrostatic spindle with high calculation accuracy and calculation efficiency is proposed.

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Wu, Rong, Shili Zhao, Yi Liu, and Shuiqiang Zhang. "Strain accuracy enhancement of stereo digital image correlation for object deformation with large rotations." Measurement Science and Technology 33, no. 5 (February 2, 2022): 055003. http://dx.doi.org/10.1088/1361-6501/ac3fc5.

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Abstract We propose a full-field stereo digital image correlation (DIC) strain measurement method to overcome the poor accuracy while measuring the deformation under large rotations. Such a drawback comes from the failure to consider rotation movements of the deformed objects when calculating their strain values. To address this, we first used a DIC matching algorithm combined with a rotated subset and feature point detection to obtain displacement fields. By employing a singular value decomposition method, we can then calculate rotation matrices of the strain windows before and after deformations. Finally, to eliminate the strain errors caused by rotation, we introduced the rotation matrices into the classical pointwise least squares DIC strain calculation method. Both numerical simulations and experiments are performed, and the accuracy and effectiveness of the proposed method are confirmed by the experimental results.

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Reese, D. R., G. M. Mirouh, F. Espinosa Lara, M. Rieutord, and B. Putigny. "Oscillations of 2D ESTER models." Astronomy & Astrophysics 645 (January 2021): A46. http://dx.doi.org/10.1051/0004-6361/201935538.

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Context. Recent numerical and theoretical considerations have shown that low-degree acoustic modes in rapidly rotating stars follow an asymptotic formula. In parallel, recent studies have revealed the presence of regular pulsation frequency patterns in rapidly rotating δ Scuti stars that seem to match theoretical expectations. Aims. In this context, a key question is whether strong gradients or discontinuities can adversely affect the asymptotic frequency pattern to the point of hindering its identification. Other important questions are how rotational splittings are affected by the 2D rotation profiles expected from baroclinic effects and whether it is possible to probe the rotation profile using these splittings. Methods. In order to address these questions, we numerically calculate stellar pulsation modes in continuous and discontinuous rapidly rotating models produced by the 2D Evolution STEllaire en Rotation (ESTER) code. This code self-consistently calculates the rotation profile based on baroclinic effects and uses a spectral multi-domain approach, thus making it possible to introduce discontinuities at the domain interfaces without loss of numerical accuracy. The pulsation calculations are carried out using an adiabatic version of the Two-dimensional Oscillation Program (TOP) code. The variational principle is then used to confirm the high numerical accuracy of the pulsation frequencies and to derive an integral formula for the generalised rotational splittings. Acoustic glitch theory, combined with ray dynamics, is applied to the discontinuous models in order to interpret their pulsation spectra. Results. Our results show that the generalised rotational splittings are very well approximated by the integral formula, except for modes involved in avoided crossings. This potentially allows the application of inverse theory for probing the rotation profile. We also show that glitch theory applied along the island mode orbit can correctly predict the periodicity of the glitch frequency pattern produced by the discontinuity or Γ1 dip related to the He II ionisation zone in some of the models. Furthermore, the asymptotic frequency pattern remains sufficiently well preserved to potentially allow its detection in observed stars.

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Alam, Mahbub, Anthony M. J. Bull, Rhidian deW Thomas, and Andrew A. Amis. "Measurement of Rotational Laxity of the Knee." American Journal of Sports Medicine 39, no. 12 (October 13, 2011): 2575–81. http://dx.doi.org/10.1177/0363546511424872.

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Background: Posterolateral corner (PLC) injuries are difficult to diagnose and cause significant morbidity. The ideal method for the dial test and its accuracy remain unclear. Purpose: This study compares the accuracy of measuring tibial external rotation at the skeletal level to measuring the patella-tubercle angle (PTA) and the thigh-foot angle (TFA) in the supine position to assess the most accurate method to measure rotation during the dial test. Study Design: Controlled laboratory study. Methods: Measurements were compared simultaneously using rotational goniometers at a cutaneous splint over the tibia, at a foot splint, and directly from the tibial skeleton. Six lower limbs were used. The femur was held rigidly and the knee tested at 90° and 30° of flexion. External rotation torque up to 8 N·m was applied through the foot splint, and the rotations were measured by 2 testers. Results: Measurements at the tibial splint and directly on the tibia showed significant correlation at both knee flexion angles. The mean tibial external rotation was 24° at 90° of flexion and 26° at 30° of flexion ( P < .05). The soft tissue effect caused the tibial splint to overestimate rotations by a mean of 6° and 9° at 90° and 30° of flexion, respectively. Foot splint measurements did not correlate significantly with tibial rotation, overestimating rotations by a mean of 103%. Intratester and intertester intraclass correlations were significant for the skin-mounted tibial splint measurements at both flexion angles but not for foot splint measurements at either flexion angles. Conclusion: Rotation of the foot did not accurately represent the tibial external rotation at the knee, which could be measured more accurately by an instrument resting on the skin via a molded tibial splint. These results suggest that the PTA, and not the TFA, should be used in the dial test. This would support the use of the supine position during the dial test. Clinical Relevance: The dial test is a commonly used method for diagnosing PLC injuries. This study helps to identify the ideal position and measuring points to use for this test; measurements based on the tibia were more accurate than those that used rotation of the foot.

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Liu, Han, Simon Laflamme, Jian Li, Caroline Bennett, William N. Collins, Austin Downey, Paul Ziehl, and Hongki Jo. "Soft Elastomeric Capacitor for Angular Rotation Sensing in Steel Components." Sensors 21, no. 21 (October 23, 2021): 7017. http://dx.doi.org/10.3390/s21217017.

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The authors have previously proposed corrugated soft elastomeric capacitors (cSEC) to create ultra compliant scalable strain gauges. The cSEC technology has been successfully demonstrated in engineering and biomechanical applications for in-plane strain measurements. This study extends work on the cSEC to evaluate its performance at measuring angular rotation when installed folded at the junction of two plates. The objective is to characterize the sensor’s electromechanical behavior anticipating applications to the monitoring of welded connections in steel components. To do so, an electromechanical model that maps the cSEC signal to bending strain induced by angular rotation is derived and adjusted using a validated finite element model. Given the difficulty in mapping strain measurements to rotation, an algorithm termed angular rotation index (ARI) is formulated to link measurements to angular rotation directly. Experimental work is conducted on a hollow structural section (HSS) steel specimen equipped with cSECs subjected to compression to generate angular rotations at the corners within the cross-section. Results confirm that the cSEC is capable of tracking angular rotation-induced bending strain linearly, however with accuracy levels significantly lower than found over flat configurations. Nevertheless, measurements were mapped to angular rotations using the ARI, and it was found that the ARI mapped linearly to the angle of rotation, with an accuracy of 0.416∘.

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Dror, Itiel E. "Visual Mental Rotation: Different Processes Used by Pilots." Proceedings of the Human Factors Society Annual Meeting 36, no. 18 (October 1992): 1368–72. http://dx.doi.org/10.1177/154193129203601802.

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Air Force pilots and control subjects were tested on a visual “mental rotation” task. Nine of the 16 pilots, as well as all of the 16 control subjects, required more time to rotate greater angular distances. The performance of the other 7 pilots was unique: their response time did not increase with greater angular rotations. The results suggest that visual mental rotation can be accomplished by at least two different processes. One process involves incremental object rotations in a multi-step mapping –like an actual physical rotation of an object– going through intermediate stages. This process requires more time to rotate greater angular distances. The other process involves direct translation in a single-step mapping. In this process, the starting position transforms into the final position in one mapping without any intermediate steps, and thus does not require more time to rotate greater angular rotation. The lack of intermediate stages, which may allow small perturbations in location to be corrected, affects the accuracy of this process; this is particularly apparent when more complex stimuli are rotated. The pilots who did not show incremental rotation effects had different and distinct error patterns, their errors increased when rotating the more complex stimuli.

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Honda, Akio, Sayaka Tsunokake, Yôiti Suzuki, and Shuichi Sakamoto. "Auditory Subjective-Straight-Ahead Blurs during Significantly Slow Passive Body Rotation." i-Perception 13, no. 1 (January 2022): 204166952110706. http://dx.doi.org/10.1177/20416695211070616.

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This paper reports on the deterioration in sound-localization accuracy during listeners’ head and body movements. We investigated the sound-localization accuracy during passive body rotations at speeds in the range of 0.625–5 °/s. Participants were asked to determine whether a 30-ms noise stimuli emerged relative to their subjective-straight-ahead reference. Results indicated that the sound-localization resolution degraded with passive rotation, irrespective of the rotation speed, even at speeds of 0.625 °/s.

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Gulyaev, P. V., Yu K. Shelkovnikov, A. V. Tyurikov, and N. I. Osipov. "High-accuracy inertial rotation-linear piezoelectric drive." Russian Electrical Engineering 81, no. 10 (October 2010): 521–23. http://dx.doi.org/10.3103/s1068371210100020.

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An Qichang, 安其昌, 张景旭 Zhang Jingxu, 杨. 飞. Yang Fei, and 赵宏超 Zhao Hongchao. "Metrology and calibration of GSSMP rotation accuracy." Infrared and Laser Engineering 47, no. 9 (2018): 917004. http://dx.doi.org/10.3788/irla201847.0917004.

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Iosif, Panagiotis, and Nikolaos Stergioulas. "Equilibrium sequences of differentially rotating stars with post-merger-like rotational profiles." Monthly Notices of the Royal Astronomical Society 503, no. 1 (February 11, 2021): 850–66. http://dx.doi.org/10.1093/mnras/stab392.

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ABSTRACT We present equilibrium sequences of rotating relativistic stars, constructed with a new rotation law that was proposed by Uryū et al. (2017). We choose rotational parameters motivated by simulations of binary neutron star merger remnants, but otherwise adopt a cold, relativistic N = 1 polytropic EOS, in order to perform a detailed comparison to published equilibrium sequences that used the Komatsu, Eriguchi and Hachisu (1989) rotation law. We find a small influence of the choice of rotation law on the mass of the equilibrium models and a somewhat larger influence on their radius. The versatility of the new rotation law allows us to construct models that have a similar rotational profile and axial ratio as observed for merger remnants, while at the same time being quasi-spherical. More specifically, we construct equilibrium sequence variations with different degrees of differential rotation and identify type A and type C solutions, similar to the corresponding types in the classification of Ansorg, Gondek-Rosińska and Villain (2009). While our models are highly accurate solutions of the fully general relativistic structure equations, we demonstrate that for models relevant to merger remnants the IWM-CFC approximation still maintains an acceptable accuracy.

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Kaewbumrung, Mongkol, and Akapak Charoenloedmongkhon. "Numerical Simulation of Turbulent Flow in Eccentric Co-Rotating Heat Transfer." Fluids 7, no. 4 (April 7, 2022): 131. http://dx.doi.org/10.3390/fluids7040131.

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Heat transfer engineering is significant in many applications, especially in buoyancy natural convection in concentric and eccentric cavities. The biggest practical challenges, in this context, are capturing the self-natural flow, estimating the mixing performance, and determining what parameters affect the temperature distribution in the cavity. In this paper, we focus on the improvement of a mathematical model, in order to enhance the accuracy of the solution, by investigating a new source term in the SST k−ω turbulence model based on the finite volume technique. The commercial numerical simulation software ANSYS Fluent 2021R1 is implemented to validate the accuracy. A concentric cavity was chosen for validation, the obtained temperature profiles at θ=0°, θ=30°, θ=60°, θ=90°, θ=120°, θ=150°, and θ=180° were compared with previous experimental data. We applied this model to four eccentric rotating scenarios, including inner counterclockwise rotation, outer counterclockwise rotation, inner–outer clockwise rotation, and inner clockwise–outer counterclockwise rotation. The numerical simulation results reveal that the new source term in the momentum equation can produce superior results in the concentric test-case. The proposed mathematical model can describe the heat transfer under the eccentric co-rotation scenario well. Furthermore, the results for eccentric cases confirm that the rotational direction affects the mixing temperature by generating a large vortex in the cavity, which increases the temperature mixing performance.

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Vo, Dinh Tung, Sergey Kheylo, and Van Quoc Nguyen. "Kinematic and dynamic accuracy of spherical mechanisms." Mechanical Sciences 13, no. 1 (January 25, 2022): 23–30. http://dx.doi.org/10.5194/ms-13-23-2022.

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Abstract. Among parallel robots, spherical robots occupy an important place. Most applications of spherical manipulators can be found in orienting devices, such as camera orienting and medical instrument alignment. A spherical parallel robot is, in general, made up of the base platform and the moving platform. This mobile platform and base are connected by three equally spaced legs, each consisting of revolute joints only. The axes of all joints intersect at a common point, which is called the center of rotation. The motion of the moving platform is confined on the surface of a sphere centered at the rotation center. A spherical parallel robot provides 3 degrees of freedom of pure rotations. These robots have been the subject of many papers dealing with the structure, the problems of position and velocity, workspace modeling, singularity analysis, and some problems with the dynamic analysis. However, not all the important problems have been solved. These concern the problem of accuracy. This paper presents accuracy of the spherical parallel. In the considered spherical manipulator, each leg consists of five kinematic pairs. The kinematic accuracy is determined on the kinematic problem. The dynamic accuracy is estimated on the equation of motion. Examples of solving the problem of determining the positioning error of the output level are presented.

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Wang, Cai Ling, Chun Xia Zhao, and Jing Yu Yang. "Local Upsampling Fourier Transform for High Accuracy Image Rotation Estimation." Advanced Materials Research 268-270 (July 2011): 1488–93. http://dx.doi.org/10.4028/www.scientific.net/amr.268-270.1488.

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A high accuracy rotation angle estimation algorithm based on Local Upsampling Fourier Transform (LUFT) is developed in this paper. The LUFT uses a hierarchical strategy to estimate the rotation, which consists of a transformation of rotation to translation, a fast coarse rotation estimation and a robust refinement stage as well. The coarse rotation is estimated through the conventional Phase Only Correlation (POC), then, it is refined by the resampling technique within a local neighborhood in frequency domain. Furthermore, as will be shown in many experiments, the LUFT can achieve high accuracy rotation estimation, where the accuracy is tunable to some extent. Specially, it is efficient and robust to noise.

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Chen, I.-Feng, Li-Fan Lin, Chun-Long Lin, Tzu-Jou Chung, Ta-Wei Tseng, and Chuang-Hsin Chiu. "Role and limitations of the geometric mean method regarding head rotation in salivary gland scintigraphy: a phantom study." Journal of Radiation Research 61, no. 5 (July 9, 2020): 697–704. http://dx.doi.org/10.1093/jrr/rraa046.

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Abstract To investigate the possible influence of head rotation on the results of salivary gland scintigraphy, a phantom study was designed to simulate clinical salivary gland scintigraphy. The quantitative accuracy of regional activity counts was compared for two data acquisition methods involving head rotation: (i) an anterior planar projection-only (ANT) method and (ii) a geometric mean (GM) method using both the anterior and posterior planar projections. The roles and limitations of the GM and ANT methods when used at different head rotation angles were examined. Parallel planar projections of a head phantom with four salivary gland simulators, containing 3.7 MBq 99mTc-sodium pertechnetate, at various rotational settings were acquired using a dual-head gamma camera. The difference between the standard activity counts (no phantom rotation) and the activity counts affected by the phantom rotation was calculated and defined as the rotational bias that decreased the accuracy of activity quantification. For small-angle rotation (≤10°), use of the GM method decreased the bias for all salivary gland simulators. In contrast, the bias of large-angle rotation (>10°) between four salivary gland simulators became conspicuous and complex in both methods. This bias may reflect different attenuation effects caused by displacement of the structures. Our data suggest that the GM method can be used when the head rotation angle is small (≤10°); however, when the head rotation angle is >10°, the non-negligible influence of head rotation should be considered during image acquisition.

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Bull, Anthony M. J., Peter J. Holt, Paul Wragg, and Alison H. McGregor. "VALIDATION OF THE USE OF A SKIN-MOUNTED DEVICE TO MEASURE OUT-OF-PLANE ROTATIONS OF THE SPINE FOR A ROWING ACTIVITY." Journal of Musculoskeletal Research 08, no. 02n03 (June 2004): 129–32. http://dx.doi.org/10.1142/s0218957704001296.

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Objective: To assess the accuracy of a skin-mounted device to measure lumbar spinal rotations in rowers. Methods: Nine subjects were each imaged in 12 extremes of lateral flexion and rotation in an open MR scanner, and the movement between external MR markers fixed to the skin, and the underlying vertebral bodies was quantified. Results: The average error in measuring the changes in the lateral flexion and rotation between the MR markers and the underlying vertebral bodies was ±5.0° (95% CI 3.5–6.4°, S.E. 0.7°) for lateral flexion and 4.4° (95% CI 3.2–5.6°, S.E 0.6°) for lateral rotation (nine subjects). Conclusions: This study has demonstrated the accuracy of using an externally mounted device to measure out-of-plane rotations for the extremes of motion achieved during a rowing activity, allowing this system to be used to quantify deviations in rowing technique. The method could be applied to other repetitive activities of the spine.

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LaScalza, Suzanne, Linda N. Gallo, James E. Carpenter, and Richard E. Hughes. "A Method for Measuring Euler Rotation Angles and Helical Axis of Upper Arm Motion." Journal of Applied Biomechanics 18, no. 4 (November 2002): 374–83. http://dx.doi.org/10.1123/jab.18.4.374.

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Clinical observation suggests that shoulder pathologies such as rotator cuff disorders and shoulder instability may alter the normal shoulder rhythm or relative motions of the structures comprising the shoulder girdle. The purpose of this study was to assess the accuracy of using a skin-mounted humeral cuff that could be used in vivo to determine Euler rotation angles and the helical axis of motion (HAM) during upper extremity movements. An in vitro model was used to compare the kinematics determined from the externally applied humeral cuff to the kinematics measured directly from the humerus. The upper extremities of five cadavers were moved through several humerus and forearm motion trials. Measurements from the humeral cuff were compared directly to the bone measurements for all trials to determine the accuracy of the Euler rotation angles. In evaluating the HAM, the orientation, location, and magnitude of rotation were compared either to the bone measurements or to the known rotational axis of the testing fixture. Euler rotation angles and the helical axis of motion determined by the measurements taken from the skin-mounted humeral cuff were very similar to those using the measurements from the bone-mounted sensor. The humeral cuff was shown to provide a viable, noninvasive method for determining the Euler rotation angles and helical axis of motion during 3-D humeral movements. The validation makes the humeral cuff a valuable tool for examining the effect of shoulder pathologies on the kinematics of the upper extremity.

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Dravins, Dainis. "Spectroscopic Measurements of Stellar Rotation." Highlights of Astronomy 10 (1995): 403–6. http://dx.doi.org/10.1017/s1539299600011540.

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This section title is identical to that of the first paper where the broadening of absorption lines in response to stellar rotation was discussed: Abney (1877).More accurate measurements now reveal also the details of stellar line shapes, making it possible to segregate the signatures of rotational and other broadening mechanisms: e.g. Gray (1992) and Smith & Gray (1976). To determine the rotation, fits can be made to line profiles (e.g. Anders et al., 1993), to their Fourier transforms (e.g. Dravins et al. 1990;Smith & Gray 1976), or to extended spectral regions (e.g. Kurucz et al. 1977).This review, however, concerns issues for [single-epoch] spectroscopic observations only, no temporal aspect will be discussed.What is observed is a rotationally broadened profile, the accuracy begins to get limited by the incomplete physical understanding of stellarline profiles and of the nature of stellar rotation. In order to disentangle the rotational broadening from other effects, one needs to know the ‘intrinsic’ (i.e. rotationally unbroadened) profile of the non-rotating star. How does this profile change with latitude and longitude across the stellar disk? What effects besides rotation are broadening the lines? What about mass loss, radial pulsation, non-radial oscillations, magnetic fields, spots, etc.? And the star might not even rotate as a rigid body, but perhaps differentially with respect to latitude and/or atmospheric height. All this has to be deduced from the often blended lines in complex spectra.

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Wu, Wei, Toshiki Hirogaki, and Eiichi Aoyama. "Proposal of Improving Method of Rotational 2-Axis Synchronous Accuracy of Plate Motion Control with a Dual Arm Robot by Estimating Ball Rolling Motion on the Plate." Key Engineering Materials 523-524 (November 2012): 889–94. http://dx.doi.org/10.4028/www.scientific.net/kem.523-524.889.

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Recently, developers of machining tools have begun paying more and more attention to multi-joint dual-arm robot, and it is expected the robot will reclaim its place in the field of new automation. Industrial dual-arm robots have therefore gained attention as new tools to control both linear motion and rotational motion accurately. On the other hand, the five-axis control machining center controlling the motion of three translation axes and two rotation axes has put into wide practical use. However, a one problem has been that it may be the difficult to measure the synchronic accuracy of rotation two axes without high accuracy gyro sensor. In the present report, we proposed a novel method to measure the synchronic accuracy of rotation two axes of machine tool table with a ball, which keeps a ball rolling around a circular path on the working plate by dual-arm cooperating control. As a result, we investigated an influence of each axis motion error on a ball- rolling path, and demonstrated this method made it feasible to estimate the synchronic accuracy of rotation two axes of machine tool table.

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Kail, Robert. "Development of mental rotation: A speed-accuracy study." Journal of Experimental Child Psychology 40, no. 1 (August 1985): 181–92. http://dx.doi.org/10.1016/0022-0965(85)90071-2.

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Zhang, Jiayu, Jie Li, Xiaorui Che, Xi Zhang, Chenjun Hu, Kaiqiang Feng, and Tingjin Xu. "The Optimal Design of Modulation Angular Rate for MEMS-Based Rotary Semi-SINS." Micromachines 10, no. 2 (February 10, 2019): 111. http://dx.doi.org/10.3390/mi10020111.

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In previous studies, the semi-strapdown inertial navigation system (SSINS), based on microelectromechanical system (MEMS) sensors, had realized cross-range measurement of attitude information of high-spinning projectiles through construction of a “spin reduction” platform of the roll axis. However, further improvement of its measurement accuracy has been difficult, due to the inertial sensor error. In order to enhance the navigational accuracy, a periodically rotating method is utilized to compensate for sensor error, which is called rotation modulation. At present, the rotation scheme, as one of the core technologies, has been studied by a lot of researchers. It is known that the modulation angular rate is the main factor affecting the effectiveness of error modulation. Different from the long-endurance and low-dynamic motion characteristics of ships, however, the short-endurance and high-dynamic characteristics of the high-spinning projectile not only require the modulation angular rate to be as fast as possible but, also, the influence of the rotation speed error caused by rotating mechanism errors cannot be ignored. Combined with the rotation speed error of the rotating mechanism, this paper explored the relationship between modulation angular rate, device error, and the navigation error, and then proposed a design method for optimal modulation angular rate. Experiments were carried out to validate the performance of the method. In addition, the proposed method is applicable for rotation modulation systems with different types of motors as the rotating mechanism.

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Giorcelli, Rebecca J., Richard E. Hughes, Richard S. Current, and John R. Myers. "Accuracy of a System for Measuring Three-Dimensional Torso Kinematics during Manual Materials Handling." Journal of Applied Biomechanics 20, no. 2 (May 2004): 185–94. http://dx.doi.org/10.1123/jab.20.2.185.

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This paper describes a procedure developed and validated to assess the accuracy of an infrared-based motion measurement system used to perform a kinematic analysis of the torso with respect to the pelvis during simulated lifting tasks. Two rigid reflective marker triads were designed and fabricated for attachment to the thorax over the 6th thoracic vertebra and the pelvis. System accuracy was assessed for planar rotation as well as rotations about multiple orthogonal axes. A test fixture was used to validate known triad orientations. The spatial coordinates of these triads were collected at 120 Hz using a ProReflex motion measurement system. Single value decomposition was used to estimate a rotation matrix describing the rigid body motion of the thorax triad relative to the sacral triad at each point in time. Euler angles corresponding to flexion, lateral bending, and twisting were computed from the rotation matrix. All measurement error residuals for flexion, lateral bending, and twisting were below 1.75°. The estimated mean measurement errors were less than 1° in all three planes. These results suggest that the motion measurement system is reliable and accurate to within approximately 1.5° for the angles examined.

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Chen, Fei Fan, Jing Feng, and Ming Hao Wang. "Study on Accuracy Test Methods for Sun Sensors." Key Engineering Materials 364-366 (December 2007): 822–26. http://dx.doi.org/10.4028/www.scientific.net/kem.364-366.822.

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Sun sensor is one of the key attitude sensors widely used in spacecraft attitude determination. Its accuracy is one of the major technical specifications. In this paper, we propose two methods for accuracy test and evaluation, which have been proved to be efficient and convenient. With these two methods, it is possible to isolate and then, eliminate the rotational error from the rotation table that holds the sun sensor so that the performance of the sun sensor can be evaluated. The proposed two methods can be also applied to test the performance for other angle measuring devices.

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Alam, Mahbub, Anthony M. J. Bull, Rhidian deW Thomas, and Andrew A. Amis. "A Clinical Device for Measuring Internal-External Rotational Laxity of the Knee." American Journal of Sports Medicine 41, no. 1 (December 31, 2012): 87–94. http://dx.doi.org/10.1177/0363546512469874.

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Background: The dial test can be improved by providing reproducible, accurate measurements to improve diagnosis and treatment comparisons. Purpose: Validation of a rotational measurement device (RMD) for measuring knee internal-external rotational laxity. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The RMD consisted of 3 components: a femoral clamp and a tibial splint using paired inclinometers to measure rotations, and a boot to apply tibial internal-external rotation torque. A separate boot inclinometer allowed for foot rotations to be measured independently. The measurements were simultaneously compared with electromagnetic “nest of birds” (NOB) sensors. Sequential paired knee measurements were taken at 4, 6, and 8 N·m of torque at 30° and 90° of flexion in 46 volunteers. Results: The correlation coefficient was 0.92 (95% CI, 0.89 to 0.94) and 0.63 (95% CI, 0.54 to 0.70) between the NOB and RMD and between the NOB and boot inclinometer, respectively. Bland-Altman analysis revealed that the RMD was on average within 2° (95% CI, 1° to −4°) of NOB readings, whereas the boot overestimated by 34° (95% CI, −9° to −58°). Maximum side-to-side differences measured by the NOB, RMD, and boot were 1°, 3°, and 21°, respectively. The mean +2× standard deviation data gave a range of side-to-side differences of less than 5° for the RMD. The intraobserver intraclass correlation was 0.9 (95% CI, 0.78 to 0.97) at both 30° and 90° of flexion, and the 95% CI of the differences between readings taken on 2 occasions, the interobserver repeatability, was 1° or less. Conclusion: The novel clinical RMD for measuring rotational laxity of the knee was portable, easy, and comfortable to use in the clinical setting. The RMD showed significant correlation and accuracy compared with sensors of known high accuracy. Side-to-side differences of less than 5° were found in 95% of normal knees, compared with differences of 13° or more for clinical diagnosis of pathological rotational laxity. Measuring knee rotation at the foot showed poor correlation and accuracy.

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Gondoin, P., M. Fridlund, D. Gandolfi, and E. Güenter. "Differential rotation on active late-type stars observed with Corot." Proceedings of the International Astronomical Union 5, S264 (August 2009): 60–62. http://dx.doi.org/10.1017/s1743921309992365.

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AbstractOne major topic in studying stellar activity is to explain how phenomena seen on the Sun and stars, and specially magnetic phenomena, depend on stellar properties such as rotation and age. Differential rotation is an important physical process in theories of stellar magnetic field generation. The solar surface differential rotation was initially discovered via the simple method of tracking the rotation rates of individual starspots at different latitudes. Adopting a similar principle, high accuracy light curves of active stars observed with the CoRoT satellite are analyzed using a model based on the rotational modulation of the visibility of active regions.

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Zha, Jun, Yaolong Chen, and Penghai Zhang. "Relationship between elliptical form error and rotation accuracy of hydrostatic journal bearing." Industrial Lubrication and Tribology 69, no. 6 (November 13, 2017): 905–11. http://dx.doi.org/10.1108/ilt-08-2016-0192.

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Purpose The form error of shaft and hole parts is inevitable because of the machining error caused by rotation error of tool axis in machine tools where the elliptical form error is the most common in shaft and bearing bush. The purpose of this paper is to present the relationship between the elliptical form error and rotation accuracy for hydrostatic journal bearing in precision spindle and rotation table. Design/methodology/approach An error averaging effect model of hydrostatic journal bearing is established by using Reynolds equation, pressure boundary conditions, flux continuity equation of the land and kinetic equation of shaft in hydrostatic journal bearing. The effects of shaft and bearing bush on rotation accuracy were analyzed quantitatively. Findings The results reveal that the effect of shaft elliptical form error on rotation accuracy was six times larger than bearing bush. Therefore, to improve the rotation accuracy of hydrostatic journal bearing in spindle or rotation table, the machining error of shaft should be controlled carefully. Originality/value An error averaging model is proposed to evaluate the effect of an elliptical form error on rotation accuracy of hydrostatic journal bearings, which solves the Reynolds equation, the flux continuity equation and the kinetic equation. The determination of form error parameters of shaft and bearing bush can be yielded from finding results of this study for precision design of hydrostatic journal bearings.

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Fürmetz, Julian, Florian Wolf, Ekkehard Euler, Peter Thaller, and Nikolaus Degen. "Medial Proximal Femoral Angle better than Neck-Shaft Angle? Influence of Rotation on the Anteroposterior Radiograph." Journal of Hip Surgery 01, no. 03 (September 2017): 146–51. http://dx.doi.org/10.1055/s-0037-1607978.

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AbstractNeck-shaft angle (NSA) and medial proximal femoral angle (MPFA) describe the geometry of the proximal femur, but they are influenced by rotation. The MPFA is closer to the right angle and therefore assumed to be less influenced. This hypothesis was tested with a mathematical approach to compare the effects of rotation and their clinical relevance on both angles. We developed a three-dimensional (3D) geometrical model representing projectional radiography of the femoral axes under rotation and derived a mathematical equation. For validation purposes, we experimentally simulated projectional radiography and compared the results to those of the equation (five different inclinations of the femoral neck (IFN) each in 13 different rotations). The validated equation was used to determine the influence of rotation (–60° to +60°) on normal valued NSA and MPFA. The mean absolute difference between calculated and experimentally measured values was 0.6° (standard deviation [SD] 0.5; 0.0–2.2). The mean calculated difference between true and projected NSA was 7.1° (SD 7.1; 0.0–22.0), and for the MPFA, it was –1.9° (SD 2.2; –7.4 to 0.0). Clinically relevant deviations (≥5°) occurred at ≥30° external or ≥ 40° internal rotation for the NSA, for the MPFA at 60° external rotation. Mathematical modeling of radiographic projection of the IFN is possible to a high level of accuracy. Our results indicate that the NSA is significantly more susceptible to deviations caused by rotation than the MPFA. Clinicians must be aware of rotational influences in radiographic projection and possibly should use the MPFA instead of the NSA. The rotational influence during X-ray imaging must be controlled accurately, and femoral torsion should be quantified in computed tomography/magnetic resonance imaging (CT/MRI) scans if possible. 3-D bone models reconstructed from digital image data can be a future option for measuring true angles. Level of evidence was basic research.

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Chang, Hsiao-Yun, Chen-Sheng Chen, Shun-Hwa Wei, and Chi-Huang Huang. "Recovery of Joint Position Sense in the Shoulder after Muscle Fatigue." Journal of Sport Rehabilitation 15, no. 4 (November 2006): 312–25. http://dx.doi.org/10.1123/jsr.15.4.312.

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Context:Fatigue of the shoulder rotator muscles may negatively affect joint position sense (JPS) and ultimately lead to injury.Objective:Recovery of shoulder JPS after muscle fatigue.Design:A repeated-measures study.Setting:Musculoskeletal research laboratory.Patients:Thirteen subjects participated in joint position error tests and isokinetic concentric strength assessment in shoulder rotation, before and after rotator muscle fatigue.Interventions:Local muscle fatigue was induced using isokinetic concentric contractions of the shoulder rotator muscles.Main Outcome Measurements:Shoulder rotator strength and JPS error signals were measured before fatigue, immediately after fatigue, and every ten minutes thereafter for one hour.Results:Before shoulder rotation muscle fatigue, the accuracy of shoulder JPS was 2.79 ± 1.67 degrees. After muscle fatigue, the accuracy decreased to 6.39 ± 2.90 degrees. Shoulder JPS was influenced up to 40 minutes after muscle fatigue, but shoulder strength was only affected for 10 minutes after muscle fatigue.Conclusions:Proprioceptive recovery was slower than strength following fatigue of the shoulder rotators.

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Huang, Qiang, and Kun Wei. "Modeling and Analysis on the Rotation Accuracy of Lathe Spindle." Advanced Materials Research 602-604 (December 2012): 1757–60. http://dx.doi.org/10.4028/www.scientific.net/amr.602-604.1757.

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The rotation accuracy of the machine spindle is an important accuracy index, and has numerous influence factors. According to the structure characteristic of the spindle system, an integrated model of the spindle rotation error is established in this paper. By this model, the impact law and cumulative effect of various error sources on spindle rotation accuracy can be analyzed. Taking the lathe spindles as an example, the modeling and analysis method for spindle error are introduced. Visualization of spindle center track is achieved by programming.

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Wang, Peng Qing, Hong Jun Wang, and He Peng Gao. "Rotating Accuracy Measurement System of Spindle Based on Three Point Method." Applied Mechanics and Materials 333-335 (July 2013): 167–71. http://dx.doi.org/10.4028/www.scientific.net/amm.333-335.167.

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In order to measure the rotating machinery fault quickly and conveniently at a construction site, a new measuring system of rotating accuracy of spindle was developed according to three point method. With summarizing the principle of error separation technique based on three point method, the function, hardware construction and software module of this module were introduced. The problem of harmonic suppression is relieved by changing the sensor arrangement. The measuring system mainly consists of three eddy current sensors ,a acquisition card and a personal computer. After a few parameters were inputted, the rotation accuracy of calculation and display could be carried out automatically on line at a construction site.

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REN, Yong-jie, Yun-chao JIN, Tong-chuang GUO, and Jia-rui LIN. "Angle measurement accuracy evaluation of rotating laser measuring system based on instantaneous rotation speed." Optics and Precision Engineering 28, no. 11 (2020): 2403–10. http://dx.doi.org/10.37188/ope.20202811.2403.

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Wang, Xue Yun, Jie Wu, and Wei Wang. "Research on Rotation Modulation for INS Based on MEMS Sensors." Advanced Materials Research 712-715 (June 2013): 1891–99. http://dx.doi.org/10.4028/www.scientific.net/amr.712-715.1891.

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nertial sensors based on Micro-electro-mechanical systems (MEMS) are leading a great prospect because they are cheap, small and light. However, large errors limit their applications in many Inertial Navigation Systems (INS). To improve accuracy of INS based on MEMS sensors, a systematic error auto-compensation method, Rotation Modulation (RM) is introduced. RM improves navigation performance without involving any other information sources, saving the essential characteristic of self-contain. The RM effects on sensor biases and navigation errors are analyzed. Different RM schemes including elements like number of rotating axis, rotation direction, continuity and speed are discussed. An INS based on MEMS sensors with an appropriate RM scheme is developed. Static and land vehicle tests are conducted, verifying the effectiveness of RM on improving inertial navigation performance. Through introducing RM, attitude accuracy is improved by 5 times, and velocity/position accuracy by nearly 10 times.

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Vormann, Kirsten, Helmut Dreizler, Hans Hübner, and Wolfgang Hüttner. "Methyl Internal Rotation Fine Structure in the Ground State Rotational Spectrum of Gauche Butane." Zeitschrift für Naturforschung A 45, no. 8 (August 1, 1990): 989–94. http://dx.doi.org/10.1515/zna-1990-0808.

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Abstract The methyl torsional fine structure in the rotational spectrum of gauche butane in the vibrational ground state was investigated in the frequency range between 10 and 141 GHz. Using the internal axis method (IAM) in the formulation of Woods, all internal rotation parameters were determined with high accuracy. The barrier height of the methyl internal rotation was determined to 11.34 (29) kJ/mol (2.710 (69) kcal/mol)

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Liu, Xixiang, Xiaosu Xu, Yiting Liu, and Lihui Wang. "A Fast and High-Accuracy Compass Alignment Method to SINS with Azimuth Axis Rotation." Mathematical Problems in Engineering 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/524284.

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Azimuth axis rotating modulation was introduced to improve the alignment accuracy of strapdown inertial navigation system (SINS) through compass algorithm, in which the limit accuracy was determined by equivalent sensor errors in the eastern and northern direction. In this modulation, horizontal sensor errors were modulated into zero mean periodic variables. Furthermore, two methods were introduced to ensure alignment accuracy and speed: (1) shortened rotating cycle and redesigned compass parameters were selected to eliminate or ease the amplification to low-frequency senor error inputs in compass loop caused by rotation and (2) a data repeated calculation method was designed to shorten prolonged alignment time caused by the above redesigned parameters. Based on a certain SINS, turntable test proves that alignment accuracy and time were significantly improved and slightly shortened in comparison with the classical compass alignment.

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Shiraki, Makoto, Shuya Ide, Joji Morinaga, Motoki Sonohata, and Masaaki Mawatari. "Accuracy of External Rotation Guide in Total Knee Arthroplasty." Orthopedics & Traumatology 61, no. 1 (2012): 124–27. http://dx.doi.org/10.5035/nishiseisai.61.124.

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van het Loo, M. "1468 poster ANCIENT WAYS, NEW INSIGHTS IN ROTATION ACCURACY." Radiotherapy and Oncology 99 (May 2011): S546—S547. http://dx.doi.org/10.1016/s0167-8140(11)71590-0.

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Rodtook, S., and S. S. Makhanov. "Numerical experiments on the accuracy of rotation moments invariants." Image and Vision Computing 23, no. 6 (June 2005): 577–86. http://dx.doi.org/10.1016/j.imavis.2005.02.001.

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Polyansky, O. L. "High-Accuracy ab Initio Rotation-Vibration Transitions for Water." Science 299, no. 5606 (January 24, 2003): 539–42. http://dx.doi.org/10.1126/science.1079558.

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De Lisi, Richard, and Jennifer L. Wolford. "Improving Children's Mental Rotation Accuracy With Computer Game Playing." Journal of Genetic Psychology 163, no. 3 (September 2002): 272–82. http://dx.doi.org/10.1080/00221320209598683.

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CHEN, DaiWei, LiPing WANG, WeiSen KONG, JianHong LIANG, Jun WU, and XiuMei GONG. "A method for predicting spindle rotation accuracy using vibration." SCIENTIA SINICA Technologica 50, no. 6 (February 27, 2020): 819–28. http://dx.doi.org/10.1360/sst-2019-0363.

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Ni, Wei Hua, Zheng Qiang Yao, and Jun Tong Xi. "Spindle Rotation Accuracy Analysis of Turntable Based on Vector Dimension Chain." Materials Science Forum 628-629 (August 2009): 179–84. http://dx.doi.org/10.4028/www.scientific.net/msf.628-629.179.

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A significant amount of research has been performed to explore the result of components tolerances on assembly quality. The paper analyzes the geometrical error sources which affect spindle rotation accuracy of turntable. Then it predicts the spindle rotation accuracy using vector dimension chain which is the most proper method to analyze assembly quality. The method is validated by tests and it could afford theory reference for spindle rotation accuracy analysis. And the computed value suggests the bearings’ rotary precision could be lower to save cost.

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Journal articles on the topic 'Rotation accuracy'

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