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1 – 10 of over 6000Fukang Deng, Kangchun Li, Xiongfeng Hu, Haifu Jiang and Fuchuan Huang
The purpose of this paper is to analyze the force and basic rating life of angular contact ball bearings of RV reducer under the actual operating condition.
Abstract
Purpose
The purpose of this paper is to analyze the force and basic rating life of angular contact ball bearings of RV reducer under the actual operating condition.
Design/methodology/approach
Force analysis of angular contact ball bearing under the actual operating condition, calculate the axial, radial load and internal load distribution, calculate the basic rating life of angular contact ball bearing under variable load conditions.
Findings
The external load has a great influence on the radial load of angular contact ball bearing, further affecting the basic rating life of angular contact ball bearing, which is a great influence on the overall life of RV reducer under the condition of high frequency and heavy load.
Originality/value
This paper provides important ideas for the design and manufacture of RV reducer in theory and experiment technology.
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Keywords
Xiaoyan Ye, Dengming Wang and Xiaojing Zheng
Granular material exhibits rich dynamical behaviors under impacting, and its impacting dynamical process is seriously influenced by many factors. The purpose of this paper is to…
Abstract
Purpose
Granular material exhibits rich dynamical behaviors under impacting, and its impacting dynamical process is seriously influenced by many factors. The purpose of this paper is to explore the dynamical response of granular bed obliquely impacted by a rotational projectile, and the effect of density ratio and diameter ratio on its penetration depth is mainly considered.
Design/methodology/approach
In most experiments, as the angular velocity and the impact velocity always produce a coupling effect on the whole impact process, then it is quite difficult to separately distinguish the influence of angular velocity. Therefore, the discrete element method is used here to achieve this purpose. The authors vary one parameter and keep other parameter unchanged, and then discuss the effect of these parameters on penetration depth statistically.
Findings
The numerical model in this paper can effectively predict the dynamical process of granular medium under impacting. The projectile’s penetration depth exhibits a similar scaling with its angular velocity under different density ratios and diameter ratios, and the angular velocity exhibits an obvious criticality.
Originality/value
A DEM code and corresponding statistical approach are used to explore the complex dynamical process of a granular material obliquely impacted by a rotation projectile.
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Li Fu, Lingling Wang and Jianghai Hu
The aim of this paper is to propose a new coning correction algorithm, based on the singular perturbation technique, for the attitude update computation with non‐ideal angular…
Abstract
Purpose
The aim of this paper is to propose a new coning correction algorithm, based on the singular perturbation technique, for the attitude update computation with non‐ideal angular rate information.
Design/methodology/approach
Unlike conventional coning correction algorithms, the new method uses angular rate two‐time scale model to construct the coning correction term of attitude update. In order to achieve balanced real/pseudo coning correction performance, the selection guidelines of the new algorithm parameters are established.
Findings
Performance of the new algorithm is evaluated by comparison with the conventional algorithm in no ideal sensors undergoing stochastic coning environments. The accuracy of attitude update can be improved effectively with reduced computational workload by using this new coning algorithm as compared with conventional ones.
Practical implications
The proposed coning correction algorithm can be implemented with angular rate sensors in UAV (unmanned aerial vehicle) and other aircrafts attitude estimation for navigation and control applications.
Originality/value
Singular perturbation is an effective method for structuring coning correction algorithm with filtered angular rate outputs in stochastic coning environments. The improved coning correction algorithm based on singular perturbations reduces the real and pseudo coning effects effectively as compared with conventional ones. It is proved to be valid for improvement of accuracy with reduced computations of the attitude update.
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Takaya Inamori, Nobutada Sako and Shinichi Nakasuka
This paper aims to present an attitude determination and control system for a nano‐astrometry satellite which requires precise angular rate control. Focus of the research is…
Abstract
Purpose
This paper aims to present an attitude determination and control system for a nano‐astrometry satellite which requires precise angular rate control. Focus of the research is methods to achieve the requirement.
Design/methodology/approach
In order to obtain astrometry data, the satellite attitude should be controlled to an accuracy of 0.05°. Furthermore, attitude spin rate must be controlled to an accuracy of 4×10−7 rad/s during observation. In this paper the following unique ideas to achieve these requirements are introduced: magnetic disturbance compensation and rate estimation using star blurred images.
Findings
This paper presents the feasibility of a high accurate attitude control system in nano‐ and micro‐satellite missions.
Practical implications
This paper presents a possibility of the application of nano‐satellites to remote‐sensing and astronomy mission, which requires accurate attitude control.
Originality/value
Originalities of the paper are the methods to achieve the high accurate attitude control: magnetic disturbance compensation and angular rate estimation using star images.
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Qiao Qiao, Jianping Yuan and Xin Ning
The purpose of this paper is to establish the dynamics model of a Z-folded PhoneSat considering hinge friction and to investigate the influence of disturbances, such as friction…
Abstract
Purpose
The purpose of this paper is to establish the dynamics model of a Z-folded PhoneSat considering hinge friction and to investigate the influence of disturbances, such as friction, stiffness asymmetry, deployment asynchronicity and initial disturbance angular velocity, on the attitude of PhoneSat during and after deployment.
Design/methodology/approach
For the Z-folded PhoneSat, the dynamics model considering hinge friction is established and the dynamics simulation is carried out. The effects of friction, stiffness asymmetry, deployment asynchronicity and initial disturbance angular velocity on the attitude motion of the PhoneSat are studied and the attitude motion regularities of the PhoneSat considering the disturbance factors mentioned above are discussed.
Findings
Friction has a main contribution to reducing the oscillation of attitude motion and damping out the residual oscillation, ultimately decreasing the deployment time. An increasing length of deployment time is required with the increasing stiffness asymmetry and time difference of asynchronous deployment, which also have slight disturbances on the attitude angle and angular velocity of PhoneSat after the deployment. The initial disturbance angular velocity in the direction of deployment would be proportionally weakened after the deployment, whereas initial disturbance angular velocity in other direction induces angular velocities of other axes, which dramatically enhances the complexity of attitude control.
Originality/value
The paper is a useful reference for engineering design of small satellites attitude control system.
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Xin Wang, Jie Yan, Dongzhu Feng, Yonghua Fan and Dongsheng Yang
This paper aims to describe a novel hybrid inertial measurement unit (IMU) for motion capturing via a new configuration of strategically distributed inertial sensors, and a…
Abstract
Purpose
This paper aims to describe a novel hybrid inertial measurement unit (IMU) for motion capturing via a new configuration of strategically distributed inertial sensors, and a calibration approach for the accelerometer and gyroscope sensors mounted in a flight vehicle motion tracker built on the inertial navigation system.
Design/methodology/approach
The hybrid-IMU is designed with five accelerometers and one auxiliary gyroscope instead of the accelerometer and gyroscope triads in the conventional IMU.
Findings
Simulation studies for tracking with both attitude angles and translational movement of a flight vehicle are conducted to illustrate the effectiveness of the proposed method.
Originality/value
The cross-quadratic terms of angular velocity are selected to process the direct measurements of angular velocities of body frame and to avoid the integration of angular acceleration vector compared with gyro-free configuration based on only accelerometers. The inertial sensors are selected from the commercial microelectromechanical system devices to realize its low-cost applications.
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Changwu Liu, Haowen Wang and Chen Jiang
The paper aims at developing a novel algorithm to estimate high-order derivatives of rotorcraft angular rates to break the contradiction between bandwidth and filtering…
Abstract
Purpose
The paper aims at developing a novel algorithm to estimate high-order derivatives of rotorcraft angular rates to break the contradiction between bandwidth and filtering performance because high-order derivatives of angular rates are crucial to rotorcraft control. Traditional causal estimation algorithms such as digital differential filtering or various tracking differentiators cannot balance phase-lead angle loss and high-frequency attenuation performance of the estimated differentials under the circumstance of strong vibration from the rotor system and the rather low update rate of angular rates.
Design/methodology/approach
The algorithm, capable of estimating angular rate derivatives to maximal second order, fuses multiple attitude signal sources through a first-proposed randomized angular motion maneuvering model independent of platform dynamics with observations generated by cascaded tracking differentiators.
Findings
The maneuvering flight test on 5-kg-level helicopter and the ferry flight test on 230-kg-level helicopter prove such algorithm is feasible to generate higher signal to noise ratio derivative estimation of angular rates than traditional differentiators in regular flight states with enough bandwidth for flight control.
Research limitations/implications
The decrease of update rate of input attitude signals will weaken the bandwidth performance of the algorithm and higher sampling rate setting is recommended.
Practical implications
Rotorcraft flight control researchers and engineers would benefit from the estimation method when implementing flight control laws requiring angular rate derivatives.
Originality/value
A purely kinematic randomized angular motion model for flight vehicle is first established, combining rigid-body Euler kinematics. Such fusion algorithm with observations generated by cascaded tracking differentiators to estimate angular rate derivatives is first proposed, realized and flight tested.
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Zhaoyang Sun, Haiyang Zhou, Tianchen Yang, Kun Wang and Yubo Hou
The shape of a product plays a crucial role in shaping consumer behavior. Despite the voluminous research on factors influencing consumers’ shape preferences, there remains a…
Abstract
Purpose
The shape of a product plays a crucial role in shaping consumer behavior. Despite the voluminous research on factors influencing consumers’ shape preferences, there remains a limited understanding of how the busy mindset, a mentality increasingly emphasized by marketing campaigns, works. This study aims to fill this gap by exploring the relationship between a busy mindset and the preference for angular-shaped versus circular-shaped products and brand logos.
Design/methodology/approach
This research consists of seven experimental studies using various shape stimuli, distinct manipulations of busy mindset, different assessments of shape preference and samples drawn from multiple countries.
Findings
The findings reveal that a busy mindset leads to a preference for angular shapes over circular ones by amplifying the need for uniqueness. In addition, these effects are attenuated when products are scarce.
Originality/value
This research represents one of the pioneering efforts to study the role of a busy mindset on consumers’ aesthetic preferences. Beyond yielding insights for practitioners into visual marketing, this research contributes to the theories on the busy mindset and shape preference.
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Hongyan Zhu, Pengzhen Lv, Xiaochong Wu, Yuansheng Wang, Wei Liu, Huagang Lin and Zhufeng Yue
This paper aims to propose a two-stage vibration isolation system for large airborne equipment to isolate aircraft vibration load.
Abstract
Purpose
This paper aims to propose a two-stage vibration isolation system for large airborne equipment to isolate aircraft vibration load.
Design/methodology/approach
First, the vibration isolation law of the discrete model of large airborne equipment under different damping ratios, stiffness ratios and mass ratios is analyzed, which guides the establishment of a three-dimensional solid model of large airborne equipment. Subsequently, the vibration isolation transfer efficiency is analyzed based on the three-dimensional model of the airborne equipment, and the angular and linear vibration responses of the two-stage vibration isolation system under different frequencies are studied.
Findings
Finally, studies have shown that the steady-state angular vibration at the non-resonant frequency changes little. In contrast, the maximum angular vibration at the resonance peak reaches 0.0033 rad, at least 20 times the response at the non-resonant frequency. The linear vibration at the resonant frequency is at least 2.14 times the response at the non-resonant frequency. Obviously, the amplification factor of linear vibration is less than that of angular vibration, and angular vibration has the most significant effect on the internal vibration of airborne equipment.
Originality/value
The two-stage vibration isolation equipment designed in this paper has a positive guiding significance for the vibration isolation design of large airborne equipment.
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Keywords
This paper presents algorithms for computing the angular velocities of the bodies of a multibody system. A multibody system is any collection of connected bodies. The focus is…
Abstract
This paper presents algorithms for computing the angular velocities of the bodies of a multibody system. A multibody system is any collection of connected bodies. The focus is upon multibody systems consisting of spherically pinned rigid bodies which do not form closed loops. Simple formulae are presented for computing the angular velocities. It is shown that once the angular velocities are known the entire kinematical description and hence, the dynamics of the system, may be developed routinely and in automated fashion. Extension to more general multibody systems follows without conceptual change in the procedures.