Simulation Prospective - Ride and Handling Characteristics of an ATV using MR Damper Input Control

2013 ◽  
Author(s):  
K. Kamalakkannan ◽  
A. ELAYAPERUMAL
Author(s):  
Anria Strydom ◽  
Pieter S. Els ◽  
Sudhir Kaul

Ride comfort and handling characteristics are two important aspects of vehicle dynamics that generally require contrasting suspension settings. Different damper settings of the suspension system are required in order to meet these conflicting requirements. A magneto-rheological (MR) damper allows variable suspension settings to achieve enhanced ride comfort as well as handling characteristics by providing adaptable damping. Implementation of semi-active control requires an accurate MR damper model and online identification of model parameters. However, modeling a MR damper for a wide range of input conditions is challenging, especially when there are constraints on necessary measurements that are required for modeling. Although the available literature proposes various parametric models, many of these models are computationally expensive and are not viable for online identification. This paper presents a non-parametric model as well as a recursive model to predict the damping force of a MR damper in order to implement a semi-active control algorithm on an off-road vehicle. The results of the two models are compared to a conventional parametric model. The recursive model is used to demonstrate the significance of including the measured damping force in the model. Whereas the availability of the measured damping force yields a reasonably accurate model, the lack of measured damping force significantly impairs the recursive model.


Author(s):  
Pakharuddin Mohd Samin ◽  
Hishamuddin Jamaluddin ◽  
Roslan Abd Rahman ◽  
Saiful Anuar Abu Bakar ◽  
Khisbullah Hudha

1991 ◽  
Vol 19 (3) ◽  
pp. 122-141 ◽  
Author(s):  
C. Wright ◽  
G. L. Pritchett ◽  
R. J. Kuster ◽  
J. D. Avouris

Abstract A method for determining the effect of suspension dynamics on tire wear has been developed. Typical city cycle maneuvers are defined by instrumented vehicle testing and data in the form of forward velocities and steer angles are used as an input to an ADAMS computer model of the vehicle. A simulation of the maneuvers generates a tire's operating environment in the form of normal load, slip, and camber variations, which contain all the subtle effects of the vehicle's suspension, steering, and handling characteristics. A cyclic repetition of the tire's operating environment is constructed and used to control an MTS Flat-Trac machine. In this way, accelerated tire wear can be generated in the laboratory which is directly related to the design features of the vehicle's suspension and steering systems.


BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e049098
Author(s):  
Tristan Van Doormaal ◽  
Menno R Germans ◽  
Mariska Sie ◽  
Bart Brouwers ◽  
Andrew Carlson ◽  
...  

ObjectiveThe dural sealant patch (DSP) is designed for watertight dural closure after cranial surgery. The goal of this study is to assess, for the first time, safety and performance of the DSP as a means of reducing cerebrospinal fluid (CSF) leakage in patients undergoing elective cranial intradural surgery with a dural closure procedure.DesignFirst in human, open-label, single-arm, multicentre study with 360-day (12 months) follow-up.SettingThree large tertiary reference neurosurgical centres, two in the Netherlands and one in Switzerland.ParticipantsForty patients undergoing elective cranial neurosurgical procedures, stratified into 34 supratentorial and six infratentorial trepanations.InterventionEach patient received one DSP after cranial surgery and closure of the dura mater with sutures.Outcome measuresPrimary composite endpoint was occurrence of one of the following events: postoperative percutaneous CSF leakage, intraoperative leakage at 20 cm H2O positive end-expiratory pressure or postoperative wound infection. Overall success was defined as achieving the primary endpoint in no more than two patients. Secondary endpoints were device-related serious adverse events or adverse events (AEs), pseudomeningocele and thickness of dura+DSP. Additional endpoints were reoperation in 30 days and user satisfaction.ResultsNo patients met the primary endpoint. No device-related (serious) AEs were observed. There were two incidences of self-limiting pseudomeningocele as confirmed on MRI. Thickness of dura and DSP were (mean±SD) 3.5 mm±2.0 at day 7 and 2.1 mm±1.2 at day 90. No patients were reoperated within 30 days. Users reported a satisfactory design and intuitive application.ConclusionsDSP, later officially named Liqoseal, is a safe and potentially efficacious device for reducing CSF leakage after intracranial surgery, with favourable clinical handling characteristics. A randomised controlled trial is needed to assess Liqoseal efficacy against the best current practice for reducing postoperative CSF leakage.Trial registration numberNCT03566602.


Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Tao Wang ◽  
Zhengmu Zhou ◽  
Yaqin Zhou

This paper presents the damping characteristics of a linear magneto-rheological (MR) damper with dual controllable ducts based on numerical and experimental analysis. The novel MR damper consisting of a dual-rod cylinder system and a MR valve is used to reduce the influences of viscous damping force and improve dynamic range. Driven by the dual-rod cylinder system, MR fluid flows in the MR valve. The pressure drop of the MR valve with dual independent controllable ducts can be controlled by tuning the current of two independent coils. Based on the mathematical model and the finite element method, the damping characteristics of the MR damper is simulated. A prototype is designed and tested on MTS machine to evaluate its damping characteristics. The results show that the working states and damping force of the MR damper can be controlled by the two independent coils.


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