Showing papers in "Mechanism and Machine Theory in 2020"

TL;DR: A survey of the state-of-the-art design advances in this research area over the past 20 years is presented and can be helpful to those engaged in the topology optimization of compliant mechanisms who desire to be apprised of the field’s recent state and research tendency.

TL;DR: The proposed mesh stiffness calculation model is proven to be more general and comprehensive since the traditional analytical models are the special cases of the proposed model.

TL;DR: The results show that the impulse factor is sensitive to fault characteristics, and the trends of various statistical indicators in the time domain and frequency domain with respect to the level of fault extension are compared and analyzed.

TL;DR: This work reviews gear lubrication papers with focus on gear efficiency, contact fatigue and dynamics, and compile and categorize key investigations in an expansive field with substantial recent research.

TL;DR: A dynamic model for herringbone planetary gear train is established and the influence mechanism of the flexible support on the load sharing characteristics is studied, and the difference in load sharing characteristic is compared.

TL;DR: A deep learning-based domain adaptation method is proposed for the cross-domain ball screw fault diagnosis problem, and the maximum mean discrepancy metric is proposed to measure and optimize the data distributions of different operating conditions.

TL;DR: Aiming at the shortcomings of the traditional model, a new high-speed fault dynamic model of ACBBs is proposed by considering the influences of centrifugal force, gyroscopic moment and time-varying contact angles on the rolling element under high speed running and using a B-spline fitting displacement excitation method to represent the fault excitation as mentioned in this paper.

TL;DR: According to the intended use of a prosthetic hand, this paper suggests some key considerations needed for developing an anthropomorphic artificial finger.

TL;DR: In this article, a new continuous contact force model for contact problems with complex geometries and energy dissipations in multibody systems is presented and discussed in this work, and a hysteresis damping force is introduced for modeling the energy dissipation during the contact process.

TL;DR: It is demonstrated that the minimum distance method does not always converge when the wheel surface is not fully convex, being an alternative methodology proposed to perform the contact detection, and the new approach described here is reliable in the identification of the contact point when realistic wheel profiles are considered.

TL;DR: In this paper, the effects of ring misalignment on the stiffness and life characteristics for both the axially loaded and combined-loaded ball bearings are discussed, and the change rules of the natural frequencies for the bearing-rotor systems with two different types of misalignations are comparatively analyzed.

TL;DR: In this paper, a three-dimensional wear prediction model is proposed for gear pairs with asymmetric rim structure and gear tooth modifications, and the contact pattern and the wear distribution are analyzed.

TL;DR: The proposed approach is capable of yielding better performance than existing techniques in terms of efficiency and jerk suppression and enables a higher level of regularity for achieving desirable motion behaviours in light of the operation requirements and joint characteristics.

TL;DR: In this article, the effect of contact wire irregularity on the pantograph-catenary dynamic performance is investigated in high-speed rail operations, and the results indicate that the catenary imperfections have a direct impact on the Pantograph-Catenary interaction, leading to an increment of the contact forces amplitude, an increase of their standard deviation, and an expansion of their contact forces range.

TL;DR: Parametric study shows that lower gait speed, lower stiffness with larger pretension of the springs contribute to the maintenance of balance, and the average absolute driving torque was reduced with the use of the passive lower limb exoskeleton.

TL;DR: In this paper, the macro geometry of a helical gear pair was optimized for low weight, high efficiency, and low noise; further, trends of optimal solutions for five combinations of the three objectives were analyzed.

TL;DR: In this paper, the authors reveal the shortcoming of the improved contact stiffness coefficient, and develop two different contact force models suited for the internal and external contact form associated with the hysteresis damping factor from Lankarani-Nikravesh contact force model (L-N model).

TL;DR: In this paper, the authors developed a comprehensive thermo-mechanical model for predicting the temperature rise in thermoplastic polymer spur gears with any desired profile geometry while running, and good agreement was found between the results of the model and the experimental measurements performed using a high-speed thermal imaging infrared camera.

TL;DR: This research aims at the accurate modeling of an ROV's tether cable with a radially multilayered circular cross-section and a new approach for analytical determination of dissipation factors for dilatational and deviatoric responses is proposed.

TL;DR: A novel performance degradation dictionary (PDD) is constructed for RUL prediction based on similarity and the similarity method can be enhanced to estimate the uncertainty of RUL.

TL;DR: A numerical model was developed to simulate the ovalization fault conditions in order to build training datasets and a deep convolutional neural network algorithm was trained with the generated datasets and used to predict the faults conditions.

TL;DR: In this article, a nonsmooth strategy for solving planar rigid multibody systems with multiple revolute clearance joints was proposed, based on the principle of Hamilton's variation, and the discrete form of the governing equations satisfies symplecticity.

TL;DR: The results indicate that the proposed method can diagnose the bearing faults with different types and degrees effectively, and the vertex domain index TVHVG is superior to some classical time domain indexes in distinguishing the different states of rolling bearings.

TL;DR: Cable-driven parallel robots (CDPRs) inherit the high load capacity and outstanding dynamics of the parallel mechanism, as well as the low inertia and large workspace of the cable mechanism, which presents excellent application prospects as high-speed pick-and-place robots.

TL;DR: Simulation results reveal that the suspended backpack with an optimally controlled variable damper improves the energy efficiency of load carriage and reduces the load force exerting on carriers for a wide range of suspension stiffness and walking conditions, representing less energy expenditure, better comfort and stronger adaptability over the passive elastic backpacks with constant suspension parameters.

TL;DR: The static force transfer of the transmission mechanism, and the establishment of dynamic equations for the passive training system are detailed, which validate the feasibility and stability of the developed FRR.

TL;DR: The important background works regarding each wheel mechanism are presented, the most important wheel mechanisms are presented and the current trending approaches are presented to assist designers and researchers to select appropriate mechanism and control approach fit to their requirements.

TL;DR: In this article, the dynamics of an on-board rotor mounted on hydrodynamic finite-length bearings is investigated in the presence of support motions which create multi-frequency parametric excitations.

TL;DR: Simulation results show that the proposed hydraulic driving system and braking control strategy helps greatly increase the braking energy recovery rate.

TL;DR: The results of two rolling bearing datasets show that NPLSSMM has great classification performance for rolling bearing fault diagnosis, but also has great advantage in running time over other matrix data classifiers.