Influences of the electromagnetic regenerative dampers on the vehicle suspension performance

2016 ◽  
Vol 231 (3) ◽  
pp. 383-394 ◽  
Author(s):  
Peng Li ◽  
Lei Zuo
Keyword(s):  
Ride Comfort ◽  
Damping Coefficient ◽  
Vehicle Suspension ◽  
Mechanical Motion ◽  
International Standardization Organization ◽  
Road Profile ◽  
Suspension Dynamics ◽  
International Standardization ◽  
Standardization Organization ◽  
Suspension Performance

Conventional vehicle suspensions suppress vehicle vibrations by dissipating the vibration energy into unrecyclable heat with hydraulic dampers. This can be a considerable amount of energy which is worthy of attention for energy recovery. Electromagnetic regenerative dampers, or shock absorbers, are proposed to harvest this dissipated energy and to improve the fuel efficiency. The suspension dynamics with these regenerative dampers can be significantly different from the suspension dynamics with conventional dampers. First, different from conventional hydraulic dampers, the electromagnetic regenerative dampers have a significantly higher inertia, which is introduced by the electromagnetic generator. This has an important impact on the suspension dynamics. Second, the damping coefficient of electromagnetic dampers is related to the electric load connected to the output of the generator and can be controllable. Although various concepts have been proposed, the influences of these types of regenerative damper on the vehicle dynamics have not yet been thoroughly investigated. This paper models two types of rotational electromagnetic regenerative damper, with and without a mechanical motion rectifier, and analyzes their influences on the vehicle suspension performance in comparison with those of the conventional damper. The modeling in this paper also considers the case when the tires lose contact with the ground. Simulations were carried out with step road profile excitations and road profile excitations defined by the International Standardization Organization in order to evaluate the influences of the equivalent inertia mass and the equivalent damping coefficient. The results showed that, with an optimized equivalent inertia mass, both types of electromagnetic damper can achieve better ride comfort performances than a constant damper does. In addition, the mechanical motion rectifier mechanism can significantly improve the ride comfort and the road-handling performance of electromagnetic regenerative dampers by reducing the negative effect of the amplified generator inertia. In addition, the energy-harvesting potential of the presented dampers under road profile excitations defined by the International Standardization Organization was evaluated.

scholarly journals Methodology of the Auditing Measures to Civil Airport Security and Protection

2016 ◽  
Vol 4 (20) ◽  
pp. 38 ◽  
Author(s):  
Ján Kolesár ◽  
Lucia Melníková ◽  
Daniela Heralová ◽  
Petr Daňko
Keyword(s):  
Airport Security ◽  
Civil Aviation ◽  
Security Audit ◽  
National Programme ◽  
International Standardization Organization ◽  
Unlawful Interference ◽  
International Standardization ◽  
Independent Auditing ◽  
Certification Requirements ◽  
Standardization Organization

Airports similarly to other companies are certified in compliance with the International Standardization Organization (ISO) standards of products and services (series of ISO 9000 Standards regarding quality management), to coordinate the technical side of standardizatioon and normalization at an international scale. In order for the airports to meet the norms and the certification requirements as by the ISO they are liable to undergo strict audits of quality, as a rule, conducted by an independent auditing organization. Focus of the audits is primarily on airport operation economics and security. The article is an analysis into the methodology of the airport security audit processes and activities. Within the framework of planning, the sequence of steps is described in line with the principles and procedures of the Security Management System (SMS) and starndards established by the International Standardization Organization (ISO). The methodology of conducting airport security audit is developed in compliance with the national programme and international legislation standards (Annex 17) applicable to protection of civil aviation against acts of unlawful interference.

Legibility of Public Information Symbols

1979 ◽  
Vol 23 (1) ◽  
pp. 448-448
Author(s):  
Harm J. Zwaga
Keyword(s):  
Standard Procedure ◽  
Public Information ◽  
International Standardization Organization ◽  
Satisfactory Method ◽  
International Standardization ◽  
Standardization Organization

A legibility test is one a set of tests to be proposed by a committee of the International Standardization Organization as a standard procedure to ensure that public information symbols can be used efficiently by the population of users. Although the method of administering has been decided upon for most of the tests, there is not yet a satisfactory method for the legibility test.

Evaluation of Human Response to Building Vibration Caused by Transit Buses

1996 ◽  
Vol 15 (1) ◽  
pp. 25-42 ◽  
Author(s):  
M. Osama Al-Hunaidi
Keyword(s):  
Evaluation Methods ◽  
Human Response ◽  
Residential Homes ◽  
International Standardization Organization ◽  
Transit Buses ◽  
International Standardization ◽  
Iso 2631 ◽  
Standardization Organization

The International Standardization Organization and several countries have published standards that provide guidance on evaluation of human response to vibration in buildings, e.g. ISO 2631-2:1989, BS 6472: 1984, and ANSI S3.29: 1983. This paper demonstrates the application of these standards for the case of vibrations induced in residential homes by transit buses. Difficulties and ambiguities in applying the standards are revealed. Several vibration evaluation methods were applied and compared including rms, rmq, peak, and vibration-dose-value methods. Actual vibration levels measured in 6 residential homes were used to assess the various methods. Two evaluation methods were identified as the most appropriate.

scholarly journals Uji Homogenitas dan Stabilitas Suhu Mini Liquid Bath untuk Kalibrasi Termometer Digital Makanan

2017 ◽  
Vol 2 ◽  
pp. 299
Author(s):  
Liza Indrayani ◽  
Margi Sasono
Keyword(s):  
Liquid Bath ◽  
Iso Gum ◽  
International Standardization Organization ◽  
Uncertainty Measurement ◽  
International Standardization ◽  
Standardization Organization

<p class="AbstrakIndonesia"><strong>Abstrak: </strong>Uji homogenitas dan stabilitas suhu di dalam Mini Liquid Bath untuk kalibrasi termometer digital dalam industri makanan atau Digital Food Thermometer telah dilakukan. Mini Liquid Bath yang akan diuji memiliki bentuk tabung silinder dengan diameter 6.5 cm dan tinggi 13.5 cm. Uji homogenitas suhu dilakukan pada gradien radial dan axial pada silinder bath dengan menggunakan 6 buah sensor termokopel dari sebuah termometer multi channel. Sementara itu, uji stabilitas suhu menggunakan sebuah termometer yang diletakkan pada titik tengah geometris di dalam bath selama beberapa waktu. Selanjutnya, hasil uji ini digunakan untuk menentukan nilai sumbangan ketidakpastian dalam proses kalibrasi termometer digital dengan cara-cara ISO-GUM (International Standardization Organization-Guide Uncertainty Measurement). Berdasarkan hasil penelitian, kondisi stabil pada Mini Liquid Bath diperoleh yaitu pada titik suhu rendah berkisar  dengan ketidakpastian dan suhu tinggi berkisar  dengan ketidakpastian  Hasil uji homogenitas, pada suhu rendah diperoleh ketidakpastian sebesar  dan suhu tinggi diperoleh ketidakpastian . Hasil kalibrasi termometer digital dengan menggunakan Mini Liquid Bath tersebut diperoleh koreksi  untuk suhu rendah dengan ketidakpastian sebesar . Sementara itu, untuk suhu tinggi diperoleh koreksi  dengan ketidakpastian sebesar . Hasil kalibrasi ini dilaporkan dengan tingkat kepercayaan  dan faktor cakupan . Dari hasil tersebut, menunjukkan bahwa pada kalibrasi titik suhu rendah, ketidakpastian pengukuran sangat besar. Hal ini diduga akibat kontribusi signifikan ketidakpastian homogenitas dan stabilitas suhu pada titik suhu rendah.<strong></strong></p>

scholarly journals Effects of Tyre Pressure on Vehicle Suspension Performance

2015 ◽  
Vol 55 ◽  
pp. 102-111 ◽  
Author(s):  
M. Hamed ◽  
B. Tesfa ◽  
F. Gu ◽  
A.D. Ball
Keyword(s):  
Simulation Study ◽  
Experimental Validation ◽  
Transfer Functions ◽  
Ride Comfort ◽  
Fuel Efficiency ◽  
Vehicle Suspension ◽  
Vehicle Handling ◽  
Parameter Variations ◽  
Standard Pressure ◽  
Suspension Performance

Incorrect inflation pressures in tyres affects the vehicle handling, passenger comfort and braking conditions in addition to causing a reduction in fuel efficiency and tyre life. To address this problem, mathematical models have been produced and an experimental validation has been carried out. The models were developed with 7-DOF, for a full car system, using MATLAB programs. In the simulation study, the suspension faults have been considered by running the models with a range of inflation pressures at four conditions i.e. at standard pressure (2.3bar) and 1.5bar on the passenger wheel, driver wheel and front wheels. In each case, an analysis was carried out on the performances of the suspension in terms of ride comfort, road handling and stability of the vehicle followed by the presentation of the results obtained. In addition, the influence of parameter variations on transfer functions as a fault detection of suspension has been introduced. This approach has been used when detecting faults of vehicle tyres being under-inflated 35% and also to detect other suspension faults in the future.

scholarly journals Comparative analysis of strategies for a semi-active suspension of a ¼ vehicle

2018 ◽  
Vol 211 ◽  
pp. 02004
Author(s):  
Matheus Melo ◽  
Suzana Avila
Keyword(s):  
Control Strategy ◽  
Linear Quadratic Regulator ◽  
Active Suspension ◽  
Damping Coefficient ◽  
Vehicle Suspension ◽  
Linear Quadratic ◽  
Limit Values ◽  
The Road ◽  
Road Profile ◽  
Suspension Model

The vehicle suspension isolates the chassis from road irregularities, reacting to forces produced by the tires and the braking torques, always keeping the road tire contact, providing stability and safety. Stability and safety are two antagonistic characteristics in suspension design, when improving one the other is impaired and vice versa. The semi-active suspension is a type of vehicle suspension that can change its stiffness and/or damping in real time depending on the vehicle response to the actual road profile. The On-Off semi-active suspension changes its damping coefficient between two fixed limit values. This work proposes an On-Off semi-active suspension model, in which the damping coefficient changes its values considering the road profile function frequency. A control strategy is proposed in a way to improve performance keeping the same simplicity, without any structural change of the semi-active suspension. On the proposed control strategy one of the damping coefficients is obtained through the linear quadratic regulator (LQR) algorithm, with the aim to set the coefficient from the gain matrix associated to the velocity of the suspended mass. This model is compared to anothers found in literature.

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