Search results for "Pension"
showing 10 items of 513 documents
Work incapacity among family caregivers : a record linkage study
2022
BackgroundFamily caregiving-related physical and mental health problems may lead to work incapacity in employed caregivers. The aim of this study was to quantify sickness absences and disability pensions (SADP) among high-intensity family caregivers available to the labour market compared with a control population.MethodsThe study sample included all individuals in Finland, who had received caregiver’s allowance and were available to the labour market in 2012 (n=16 982) and their controls (n=35 371). Information on the number of sickness absence (spells >10 days) and disability pension (SADP) days and related diagnoses according to ICD-10 were obtained from national registers for the yea…
Adaptive real-time estimation on road disturbances properties considering load variation via vehicle vertical dynamics
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http:/dx.doi.org/10.1155/2013/283528 Open Access Vehicle dynamics are directly dependent on tire-road contact forces and torques which are themselves dependent on the wheels' load and tire-road friction characteristics. An acquisition of the road disturbance property is essential for the enhancement of vehicle suspension control systems. This paper focuses on designing an adaptive real-time road profile estimation observer considering load variation via vehicle vertical dynamics. Firstly, a road profile estimator based on a linear Kalman filter is proposed, which has g…
Semiactive Control Methodologies for Suspension Control With Magnetorheological Dampers
2012
Authors version of an article published in the journal: IEEE/ASME Transactions on Mechatronics. Also available from the publisher at: http://dx.doi.org/10.1109/TMECH.2011.2107331 Suspension systems are one of the most critical components of transportation vehicles. They are designed to provide comfort to the passengers to protect the chassis and the freight. Suspension systems are normally provided with dampers that mitigate these harmful and uncomfortable vibrations. In this paper, we explore two control methodologies (in time and frequency domain) used to design semiactive controllers for suspension systems that make use of magnetorheological dampers. These dampers are known because of th…
Optimization and finite-frequency H ∞ control of active suspensions in in-wheel motor driven electric ground vehicles
2015
Abstract In this paper, the parameter optimization and H ∞ control problem of active suspensions equipped in in-wheel motor driven electric ground vehicles are investigated. In order to better isolate the force transmitted to motor bearing, dynamic vibration absorber (DVA) is installed in the active suspension. Parameters of the vibration isolation modules are also optimized in order to achieve better suspension performances. As the human body is much sensitive to vibrations between 4 and 8 Hz, a finite-frequency state-feedback H ∞ controller is designed to achieve the targeted disturbance attenuation in the concerned frequency range while other performances such as road holding capability …
CFD simulations of dense sloid-liquid suspensions in baffled stirred tanks: Prediction of suspension curves
2011
Mixing of solid particles into liquids within contactors mechanically agitated by stirrers is a topic of primary importance for several industrial applications. A great research effort has been devoted to the assessment of the minimum impeller speed (Njs) able to guarantee the suspension of all particles. Conversely, only little attention has been paid so far to the evaluation of the amount of solid particles that are suspended at impeller speeds lower than Njs. In some cases the loss in available interfacial area between particles and liquid could be reasonably counterbalanced by a decreased mechanical power, making it of interest to evaluate the percentage of suspended solids at different…
Geometrical analysis of self-compensating suspension systems for railcar engineering
2002
The present analysis addresses several passive tilt systems for railroad cars aiming to compensate for the cart deficiency on curved tracks. To this end, the virtual centre of suspension must be located as close as possible to the longitudinal plane of symmetry of the coach, above the mass centre level for stability reasons. On the one hand, pantograph or Peaucellier's mechanisms may achieve the correct self-compensation. On the other hand, simpler articulated systems yield the desired goal with an excellent approximation. For example, selective algorithms can be applied for designing eight-link mechanisms, to be optimized thereafter by some method of the gradient type, minimizing the mean…
Heuristic and Backstepping Control Strategies for Semiactive Suspension in Automotive Systems Equipped with MR Dampers
2010
Abstract This paper deals with the problem of semiactive vibration reduction in a class of automotive systems. Most conventional suspensions use passive devices to absorb impacts and vibrations, which is generally difficult to adapt to the uncertain circumstances. Semiactive suspension techniques promise a solution to the above problem with some comparatively better features than active and passive suspension devices. In this work, the semiactive suspension with magnetorheological (MR) dampers is applied for the vibration attenuation. Both backstepping and heuristic control strategies are proposed. In the design of backstepping controller, the Dahl model of the MR damper is used to estimate…
CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of solid particle distribution
2013
Abstract Industrial tanks devoted to the mixing of solid particles into liquids are often operated at an impeller speed N less than Njs (defined as the lowest speed allowing the suspension of all particles): under such conditions the distribution of solid-particles is very far from being homogeneous and very significant concentration gradients exist. The present work is devoted to assessing the capability of Computational Fluid Dynamics (CFD) in predicting the particle distribution throughout the tank. The CFD model proposed by Tamburini et al. [58] and successfully applied to the prediction of the sediment amount and shape was adopted here to simulate the particle distribution under partia…
Landing gear suspension control through adaptive backstepping techniques with H∞ performance
2011
Author's version of a chapter published in the book: Proceedings of the 18th IFAC World Congress 2011. Also available from the publisher at: http://dx.doi.org/10.3182/20110828-6-IT-1002.00589
Computer active control of damping fluid of a racing superbike suspension scheme for road safety improvement spin-off
2008
This paper describes in detail a computational investigation of a newly-conceived scheme of hydraulic active racing motorcycle suspension and its design application based on a computer-aided control of damping fluid. Through ad hoc tests on a full-scale model setup and the theoretical approach of a non linear 8th-order suspension scheme, this study gives enhancement of the damping fluid active control on the feedback branch of the entire control system for significant improvement of the suspension response to typical road inputs. Briefly, the fluid flow in suspension dampers - generated through well-suited high-pressure hydraulic circuit - shall be conveniently controlled in direction and m…