A procedure for inverse kinetic analysis on two hard fingers grasping a hard sphere is proposed in this study. Contact forces may be found for given linear and angular accelerations of a spherical body. Elastic force-displacement relations predicted by Hertz contact theory are used to remove the indeterminancy produced by rigid body modelling. Two types of inverse kinetic analysis may be dealt with

Two alternative schemes used for the solution of multibody systems are reported and compared between them to evaluate their performance. Within the context of kinematic constraints imposed via augmented Lagrangian technique, one scheme proposes a simultaneous iterative solution for the computation of the Lagrangian multipliers and the nonlinear Newton-Raphson iterations. The second scheme uses a more

In this paper, the semi-active suspension in railway vehicles based on the controlled Magnetorheological (MR) fluid dampers is examined, and compared with the semi-active low and semi-active high suspension systems to enhance the running safety, ride quality and ride comfort for a high-speed rail vehicle. Fuzzy logic and chaotic fruit fly control techniques are used as system controllers to determine

Contact description plays an important role in modeling of applications involving flexible multibody dynamics. Example of such applications include contact between a belt and pulley, crash-worthiness analysis in aerospace and automotive engineering. Approaches such as the linear complementarity problem (LCP), nonlinear complementarity problem (NCP) and penalty method have been proposed for contact

The shaft and pedestal deformations can produce large misalignments and displacements of shaft-bearing-pedestal systems (SBPSs). The phenomena have a great influence on the working performances of the SBPS. Thus, the shaft and pedestal stiffness should be properly optimized to minimize the system vibrations during the design process of the SBPSs. To overcome this issue, a new shaft and pedestal stiffness

Wheel wear (W-wear) is one of the most critical issues affecting vehicle-track performances and operating costs. Currently, the works on W-wear behavior and W-wear reduction are mainly based on four aspects: wheel-rail (WR) tribology, WR profile, vehicle structure design and active control of vehicle suspensions. Little attention has been paid to the effects of track layout parameters, such as superelevation

In this paper, a mathematical model to predict acoustic responses of high-speed bearing has been developed and demonstrated in an application of Induction motors. Effect on the acoustic behaviour of bearing has studied by modifying the internal geometry, such as the number of rotating elements, curvature ratio, rotating speed with the oval shape of the track raceway due to pre-operational damage. The

Ball bearings are an integral part of many machines and mechanisms and often determine their performance limits. Vibration, friction and power loss are some of the key measures of bearing performance. Therefore, there have been many predictive analyses of bearing performance with emphasis on various aspects. The current study presents a mathematical model, incorporating bearing dynamics, mechanics

This work focuses on the importance of laser location and its effect on contact mode, tapping mode, and bimodal AFM both theoretically and experimentally. It is found that the current guidelines in the field might lead to mischaracterization of matter especially in bimodal AFM. A numerical study is done for a cantilever with its tip located at the end while interacting with two different polymers of

The drive shaft system with a tripod joint is known to cause lateral vibration in a vehicle due to the axial force generated by various contact pairs of the tripod joint. The magnitude of the generated axial force, however, is related to various operating factors of the drive shaft system in a complex manner. The generated axial force due to a drive shaft system with a tripod joint and a ball joint

This paper presents a framework for generating explicit quintic polynomial curves as the trajectory of autonomous vehicles. The method is called SCR-Normalize and is founded on two novel ideas. The first concept is to rotate the coordinate reference, regarding the boundary conditions, in order to reach a special coordinate reference called Secondary Coordinate Reference (SCR). In the SCR, the explicit

In order to enhance sampling efficiency and security when robot maintains power transmission line (PTL), this article develops a new approach for the rigid-flexible coupling dynamics of robot/PTL system, which decouples the large system into two small systems and solves them separately by estimating the contact force. The robot is modelled as a system of rigid bodies by screw theory, while the PTL

Implementation of tuned mass dampers is the commonly used approach to avoid excessive vibrations in civil engineering. However, due to the absence of the compact dimension, there are still no practical applications of the tuned mass dampers in automotive industry. Meanwhile, recent investigations showed the benefit of utilizing a tuned mass damper in a vehicle suspension in terms of driving comfort

In this paper, an explicit dynamic model of Delta robot is obtained analytically. The main contribution of this work is that, unlike existing prior work, the final dynamics model is given directly in the form of MX··+CX·+G=JTτ, with explicit expressions for M, C and G. This is of great importance, since many advanced control techniques like Optimal Control need dynamic model in an explicit form, i

This work attempts to study the vibration response of a double-row self-aligning ball bearing due to surface and localized imperfections. For the contact deformation at the ball–race interactions, the Hertzian load–deflection relation is used for the evaluation of time-varying contact stiffness. The elastohydrodynamic theory is applied to find out the central film thickness. For both the inner and

The rotational speed is a crucial parameter for bearing condition monitor. The present study shows the influence of the rotational speed on the impact characteristics caused by a localized defect of the outer raceway. A 2Nb + 5-degrees-of-freedom nonlinear dynamic model for a ball bearing is developed. The waviness of bearing components, a localized defect of the outer raceway, and the centrifugal

Abdolbaghi B, Shahram EH and Adel M. Modelling and Control of a Flapping Wing Robot. Proc IMechE Part K: J Multi-body Dynamics 2019; 233: 174–181. DOI: 10.1177/1464419318793503.

In order to control the wheel–rail coupling vibration of an urban railway system, a combined elastic wheel damping structure is proposed where the key parameters that determine the structural damping and thereby control the vibration of the railway system are explored. The vertical acceleration of the elastic wheels is obtained for a range of stiffness coefficients as the wheel moves on an irregular

The present work contributes to the analysis of dynamic behavior of long wall coal shearer traction unit through dynamic model of geared drives. In contrast to the majority of the models in the literature, complete machine dynamic model of coal shearer is introduced for obtaining dynamic gear loads for traction unit. A new stochastic coal cutting loads model is presented. Predicted vibration accelerations

In this paper, the problem of stabilization and tracking control of uncertain flexible multivariable continuum mechanism systems with additional appendage considering boundedness of undesired vibrational effects are investigated. It is proposed that rather than controlling the entire dynamical system through installation of additional actuators on appendage, it is more desirable to stabilize the core

Axle bearings are critical elements of high-speed trains. Although the quality and precision of axle bearings have been significantly improved, the manufacturing errors, such as the roundness and waviness errors, cannot be eliminated during their manufacturing processes. The axle bearings with the roundness and waviness errors have great influences on vibration performances of the high-speed trains

To reduce sliding friction work and clutch judder, an adaptive method of torque characteristic in dual clutch transmission during launch phase is presented in this paper. The proposed approach provides a tool to identify the change of torque characteristic and adapt it in real time. Firstly, to reduce the influence of the error between the nominal engine torque and the actual engine torque, the estimator

In this paper, effects of lightweight gear blank on static and dynamic behavior for electric drive system in electric vehicles are studied. First, a hybrid finite element-analytical method is proposed in this paper to establish gear load contact analysis model considering the structure of lightweight gear blank, which can balance the computing speed and numerical accuracy. Second, this paper establishes

The flexible hub-beam system is a typical structure of the rigid-flexible coupling dynamic system. In this paper, the dynamic property of the flexible hub-beam system is investigated. First, based on the dynamic analysis of the flexible beam in the flexible hub-beam system, the dynamic model of a flexible hub-beam-tip mass system is established and researched. Second, the dynamic response of the flexible

The operating clearance in a bearing influences friction, load zone size and fatigue life of a bearing. Hence, an effort is made to investigate the effect of radial internal clearance on the dynamical behavior of a cylindrical roller bearing system with an unbalance present in the system. The differential equations representing the dynamics of the cylindrical roller bearings have been derived using

The cutter head of a tunnel boring machine may be trapped in extremely adverse geological environments, which requires a large enough driving torque to get rid of the trapped condition. In this paper, a novel driving scheme is proposed to improve the driving performance of the tunnel boring machine cutter head without increasing the installation power. First, the hydro-viscous clutch is introduced

Two-dimensional large-amplitude liquid sloshing in the rectangular rigid container is numerically simulated through absolute nodal coordinate finite element method, which can describe the large deformation of continuum by using a small number of elements. The incompressible constraint of Newtonian fluid is imposed by the penalty function method. Furthermore, the motion of rigid container is described

This context exhaustively investigates the ride comfort performance index on the proposed active suspension vehicle system. Ride comfort in terms of occupants (includes driver and passenger) head acceleration, sprung mass vertical and pitching accelerations is considered. For this examination, a 14-degree-of-freedom human vehicle road integrated system model was extensively developed. Then, an active

The investigation of the end-point trajectory and the nonlinear oscillation of elastic manipulator with offset payload mounted on moving base has been carried out by demonstrating the modal parameters and dynamic responses of a bi-directionally deflected rotating flexible link manipulator. A large deflection model of a flexible rotating manipulator considering both transverse and axial deformation

To better understand the optimization of the stator profile to improve the dynamic performance of a novel profiled chamber metering pump, this paper presents a dynamic analysis method for transition curve design and optimization of the profiled chamber. The face-shaped curve of the inner chamber of the stator is formed of two quarter circular arcs and two quarter noncircular arcs, and the two quarter

Contact-impact problems have attracted more and more attention in mechanical multibody systems. In the past period of time, a few compliant contact force models have been put forward. However, some compliant contact force models are only applicable to a specific range of coefficient of restitution impact problems. And, some compliant contact force models have large errors with the actual situation

This paper presents a comfort-oriented adaptive fuzzy-model predictive control strategy to control the lateral motion of a vehicle with the steering angle as the input while preventing sudden changes and unwanted motions. This is reached by utilizing three main contributions: an adaptive fuzzy model based on look-ahead dynamics, limiting the controller to the acceptable range of states to the driver

The star herringbone gear transmission system has a high load-carrying capacity, and is widely used in aviation, marine power drives, off-road vehicles, and hybrid electric-drive vehicles. Vibration and noise are the key concerns with this transmission system. The lumped mass method was adopted to establish the dynamic model and equations of this system. The modes of the system were analyzed and classified

Motion cueing algorithms are used to produce a motion which feels as realistic as possible while remaining in the limited workspace of driving simulators. Several optimal motion cueing algorithms were developed to improve both the exploitation of the workspace of a driving simulator and the realistic of the simulated motion. In the dynamics model of the optimal motion cueing algorithms, several kinds

The bearing clearance, external torque, and input speed can greatly affect vibrations of the planetary gear system. The double-row planetary gear systems are commonly used in the gearbox of special vehicles, which are the key parts to obtain a larger gear ratio. Although many works have been presented to study those factors on vibrations of the single-row planetary gear system, a few works were focused

Vehicles for planetary exploration have to operate in completely different environments from Earth. For this reason, the design process of the exploration unit has an important role and can affect the requirements of the entire mission for the different space agencies involved. These operations are very expensive and time consuming, so that, over the years, ad hoc CAE methods have been developed to

In this paper, the Chebyshev polynomial approximation is firstly utilized to analyze the dynamical characteristics of the nonlinear vibration energy harvester with an uncertain parameter. First, the stochastic energy harvester is transformed into a high-dimensional equivalent deterministic system by the Chebyshev polynomial approximation. And the ensemble mean response of the stochastic energy harvester