scholarly journals Method for Determining Accurate Initial Air Pressure Range of Air Suspension Airbag Based on Vehicle Ride Comfort Simulation Analysis

2019 ◽  
Vol 538 ◽  
pp. 012068
Author(s):  
Quan Zhou ◽  
Puguang Yuan ◽  
Tim Tudor ◽  
Xudong Wang ◽  
Zhangwei Guo ◽  
...  
Keyword(s):  
Pressure Range ◽  
Ride Comfort ◽  
Simulation Analysis ◽  
Air Pressure ◽  
Air Suspension

scholarly journals AIR PRESSURE CONTROLLED MASS MEASUREMENT SYSTEM

2013 ◽  
Vol 24 ◽  
pp. 1360002
Author(s):  
RUILIN ZHONG ◽  
JIAN WANG ◽  
CHANGQING CAI ◽  
HONG YAO ◽  
JIN'AN DING ◽  
...  
Keyword(s):  
Measurement System ◽  
Pressure Range ◽  
Mass Measurement ◽  
Air Pressure ◽  
Air Density ◽  
Airtight Chamber ◽  
And Control ◽  
Automatic Mass ◽  
Pressure Controlled ◽  
Control Part

Mass measurement is influenced by air pressure, temperature, humidity and other facts. In order to reduce the influence, mass laboratory of National Institute of Metrology, China has developed an air pressure controlled mass measurement system. In this system, an automatic mass comparator is installed in an airtight chamber. The Chamber is equipped with a pressure controller and associate valves, thus the air pressure can be changed and stabilized to the pre-set value, the preferred pressure range is from 200 hPa to 1100 hPa. In order to keep the environment inside the chamber stable, the display and control part of the mass comparator are moved outside the chamber, and connected to the mass comparator by feed-throughs. Also a lifting device is designed for this system which can easily lift up the upper part of the chamber, thus weights can be easily put inside the mass comparator. The whole system is put on a marble platform, and the temperature and humidity of the laboratory is very stable. The temperature, humidity, and carbon dioxide content inside the chamber are measured in real time and can be used to get air density. Mass measurement cycle from 1100 hPa to 200 hPa and back to 1100 hPa shows the effective of the system.

Electronic Control Unit Design of Electronically Controlled Air Suspension (ECAS) for Vehicle Based on Freescale Microcontroller

2014 ◽  
Vol 494-495 ◽  
pp. 242-245
Author(s):  
Xin Qiang Liu ◽  
Tian Yi Yan
Keyword(s):  
Ride Comfort ◽  
Electronic Control Unit ◽  
Control Unit ◽  
Automotive Electronics ◽  
Electronic Control ◽  
Hardware System ◽  
Air Suspension ◽  
Signal Collection ◽  
Basic Ideas ◽  
Electronically Controlled Air Suspension

With the development of automotive electronics industry, the car which has electronically controlled air suspension is gained wide application. we designed an electronic control unit of automobile electronically controlled air suspension system (ECAS) including the hardware system which include the speed signal collection and processing circuit, the solenoid valve drive circuit, the CAN communication design, height detection circuit, Freescale microcontroller etc and the control strategy while propose some the basic ideas, based on Freescale microcontroller, after introducing the composition and the principle of electronically controlled air suspension. The ECAS can improve vehicle fuel economy, ride comfort and traffic-ability.

Analysis of the energy harvesting potential–based suspension for truck semi-trailer

2018 ◽  
Vol 233 (11) ◽  
pp. 2955-2969 ◽  
Author(s):  
Mohamed AA Abdelkareem ◽  
Mina MS Kaldas ◽  
Mohamed Kamal Ahmed Ali ◽  
Lin Xu
Keyword(s):  
Ride Comfort ◽  
Simulation Analysis ◽  
Conflict Analysis ◽  
Driving Safety ◽  
Dissipated Energy ◽  
Ride Quality ◽  
Surface Model ◽  
Long Distance ◽  
Class C ◽  
The Right

As the articulated trucks are mainly used for long distance transportations, the design of the suspension system became a major concern and a research hotspot not only for ride comfort and driving safety but also for energy consumption. Therefore, the objective of this study is to conduct a comprehensive parametrical–based conflict analysis between the ride comfort and road holding together with the potential power of the shock absorbers. The simulation analysis is performed using a 23 degree-of-freedom full truck semi-trailer mathematical model with random road surface model. The bounce and combined excitation modes for the truck model are applied to present the pro and contra of the simplified and realistic analysis. The bounce mode is applied for a road Class C and truck driving speed of 20 m/s, while the combined mode is performed with the same truck-speed but considering a Class C road for the left track and Class D road for the right track considering the time delay between the truck axles. The truck dynamics including the mean potential power, average dynamic tire load and bounce, and pitch and roll accelerations is comprehensively combined in the conflict analysis–based suspension and driving parameters. The obtained simulation results showed that the articulated truck suspension should be designed considering a realistic excitation condition. In contrast to the bounce mode, under the combined road input, the tractor ride quality and road handling performances are improved when a heavily damped suspension is considered. Furthermore, the otherwise dissipated energy through the damping events can reach an overall value between 2 and 4 kW.

Modified Schema for Classifying Positive-Pressure Tympanograms

PEDIATRICS ◽  
1982 ◽  
Vol 69 (3) ◽  
pp. 351-354
Author(s):  
Clyde G. Smith ◽  
Jack L. Paradise ◽  
Tina I. Young
Keyword(s):  
Clinical Practice ◽  
Pressure Range ◽  
Present Report ◽  
Acute Infection ◽  
Air Pressure ◽  
Positive Pressure ◽  
High Compliance

Tympanograms with peaks located in the high-positive air pressure range (≥ 50 mm H2O) are infrequently recorded in clinical practice and have been little discussed in the literature. Such tympanograms accounted for 1.2% of a series of 8,011 tympanograms recorded at various times from 1,556 subjects ranging in age from 7 months through 12 years. Correlations between otoscopic diagnoses and tympanometric findings in the case of 65 of the high-positive air pressure tympanograms form the basis of the present report. Of the 65 high-positive air pressure tympanograms, 51 showed relatively high compliance (≤5.5 Madsen units), and of these 46 (90%) were associated with ears considered normal otoscopically. Fourteen of the high-positive air pressure tympanograms showed low compliance (>5.5 Madsen units), and of these, six (43%) were associated with ears considered normal, six (43%) with ears showing signs of acute infection, and two (14%) with ears in which the presence of effusion seemed probable. A previously presented zonal schema for classifying tympanograms has been modified on the basis of these findings.

Automobile active tilt based on active suspension with H∞ robust control

2020 ◽  
pp. 095440702096620
Author(s):  
Jialing Yao ◽  
Meng Wang ◽  
Yanan Bai
Keyword(s):  
Robust Control ◽  
Degrees Of Freedom ◽  
Load Transfer ◽  
Ride Comfort ◽  
Simulation Analysis ◽  
Active Suspension ◽  
Roll Angle ◽  
Lateral Acceleration ◽  
Roll Moment ◽  
Roll Control

Automobile roll control aims to reduce or achieve a zero roll angle. However, the ability of this roll control to improve the handling stability of vehicles when turning is limited. This study proposes a direct tilt control methodology for automobiles based on active suspension. This tilt control leans the vehicle’s body toward the turning direction and therefore allows the roll moment generated by gravity to reduce or even offset the roll moment generated by the centrifugal force. This phenomenon will greatly improve the roll stability of the vehicle, as well as the ride comfort. A six-degrees-of-freedom vehicle dynamics model is established, and the desired tilt angle is determined through dynamic analysis. In addition, an H∞ robust controller that coordinates different performance demands to achieve the control objectives is designed. The occupant’s perceived lateral acceleration and the lateral load transfer ratio are used to evaluate and explain the main advantages of the proposed active tilt control. To account the difference between the proposed and traditional roll controls, a simulation analysis is performed to compare the proposed tilt H∞ robust control, a traditional H∞ robust control for zero roll angle, and a passive suspension system. The analysis of the time and frequency domains shows that the proposed controller greatly improves the handling stability and anti-rollover ability of vehicles during steering and maintains acceptable ride comfort.

scholarly journals Sliding Mode Control of Laterally Interconnected Air Suspensions

2020 ◽  
Vol 10 (12) ◽  
pp. 4320 ◽  
Author(s):  
Dou Guowei ◽  
Yu Wenhao ◽  
Li Zhongxing ◽  
Amir Khajepour ◽  
Tan Senqi
Keyword(s):  
Ride Comfort ◽  
Control Method ◽  
Sliding Mode ◽  
Suspension System ◽  
Lateral Acceleration ◽  
Sliding Mode Controller ◽  
The Road ◽  
Air Suspension ◽  
Simulation Based ◽  
Different Levels

This paper presents a control method based the lateral interconnected air suspension system, in order to improve the road handling of vehicles. A seven-DOF (Degree of freedom) full-vehicle model has been developed, which considers the features of the interconnected air suspension system, for example, the modeling of the interconnected pipelines and valves by considering the throttling and hysteresis effects. On the basis of the well-developed model, a sliding mode controller has been designed, with a focus on constraining and minimizing the roll motion of the sprung mass caused by the road excitations or lateral acceleration of the vehicle. Moreover, reasonable road excitations have been generated for the simulation based on the coherence of right and left parts of the road. Afterwards, different simulations have been done by applying both bumpy and random road excitations with different levels of roughness and varying vehicle lateral accelerations. The simulation results indicate that the interconnected air suspension without control can improve the ride comfort, but worsen the road handling performance in many cases. However, by applying the proposed sliding mode controller, the road handling of the sprung mass can be improved by 20% to 85% compared with the interconnected or non-interconnected mode at a little cost of comfort.

Analytical and Experimental Evaluation of Various Active Suspension Alternatives for Superior Ride Comfort and Utilization of Autonomous Vehicles

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Ivan Cvok ◽  
Mario Hrgetić ◽  
Matija Hoić ◽  
Joško Deur ◽  
Davor Hrovat ◽  
...  
Keyword(s):  
Autonomous Vehicles ◽  
High Performance ◽  
Ride Comfort ◽  
Simulation Analysis ◽  
Linear Quadratic Regulator ◽  
Active Suspension ◽  
Vertical Acceleration ◽  
Linear Quadratic ◽  
Seat Suspension ◽  
Road Disturbance

Abstract Autonomous vehicles (AVs) give the driver opportunity to engage in productive or pleasure-related activities, which will increase AV’s utility and value. It is anticipated that many AVs will be equipped with active suspension extended with road disturbance preview capability to provide the necessary superior ride comfort resulting in almost steady work or play platform. This article deals with assessing the benefits of introducing various active suspensions and related linear quadratic regulator (LQR) controls in terms of improving the work/leisure ability. The study relies on high-performance shaker rig-based tests of a group of 44 drivers involved in reading/writing, drawing, and subjective ride comfort rating tasks. The test results indicate that there is a threshold of root-mean-square vertical acceleration, below which the task execution performance is similar to that corresponding to standstill conditions. For the given, relatively harsh road disturbance profile, only the fully active suspension with road preview control can suppress the vertical acceleration below the above critical superior comfort threshold. However, when adding an active seat suspension, the range of chassis suspension types for superior ride comfort is substantially extended and can include semi-active suspension and even passive suspension in some extreme cases that can, however, lead to excessive relative motion between the seat and the vehicle floor. The design requirements gained through simulation analysis, and extended with cost and packaging requirements related to passenger car applications, have guided design of two active seat suspension concepts applicable to the shaker rig and production vehicles.

scholarly journals Ride Blending Control for Electric Vehicles

2019 ◽  
Vol 10 (2) ◽  
pp. 36 ◽  
Author(s):  
Vincenzo Ricciardi ◽  
Valentin Ivanov ◽  
Miguel Dhaens ◽  
Bert Vandersmissen ◽  
Marc Geraerts ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Ride Comfort ◽  
Simulation Analysis ◽  
Superior Performance ◽  
Ride Quality ◽  
Active Suspensions ◽  
Control Functions ◽  
Performance Indexes ◽  
Advanced Control ◽  
Passive Suspension System

Vehicles equipped with in-wheel motors (IWMs) feature advanced control functions that allow for enhanced vehicle dynamics and stability. However, these improvements occur to the detriment of ride comfort due to the increased unsprung mass. This study investigates the driving comfort enhancement in electric vehicles that can be achieved through blended control of IWMs and active suspensions (ASs). The term “ride blending”, coined in a previous authors’ work and herein retained, is proposed by analogy with the brake blending to identify the blended action of IWMs and ASs. In the present work, the superior performance of the ride blending control is demonstrated against several driving manoeuvres typically used for the evaluation of the ride quality. The effectiveness of the proposed ride blending control is confirmed by the improved key performance indexes associated with driving comfort and active safety. The simulation results refer to the comparison of the conventional sport utility vehicle (SUV) equipped with a passive suspension system and its electric version provided with ride blending control. The simulation analysis is conducted with an experimentally validated vehicle model in CarMaker® and MATLAB/Simulink co-simulation environment including high-fidelity vehicle subsystems models.

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