Application of Practical Observer to Semi-Active Suspensions

1998 ◽  
Vol 122 (2) ◽  
pp. 284-289 ◽  
Author(s):  
H. Nakai ◽  
S. Oosaku ◽  
Y. Motozono
Keyword(s):  
Ride Comfort ◽  
Difficult Problem ◽  
Nonlinear Observer ◽  
Vertical Acceleration ◽  
Acceleration Sensor ◽  
Active Suspensions ◽  
Linear Observer ◽  
Gain Scheduled

This paper presents the development of gain-scheduled observers for semi-active suspensions. The states of the semi-active suspensions must be accurately obtained because the accuracy directly affects system performances such as ride comfort. Nonlinearity in the absorber of the semi-active suspensions is a difficult problem for estimating the accurate states using conventional linear observer theories. To solve this problem, we have designed a new gain-scheduled observer by introducing two improvements. The validity of this nonlinear observer was confirmed by simulations and experiments. The results indicate that the present observer can accurately estimate the suspension stroke velocity using the vertical acceleration sensor on the sprung mass. [S0022-0434(00)02302-9]

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 Effect of the Anti-Yaw Damper on Carbody Vertical Vibration and Ride Comfort of Railway Vehicle

2020 ◽  
Vol 10 (22) ◽  
pp. 8167
Author(s):  
Mădălina Dumitriu ◽  
Dragoș Ionuț Stănică
Keyword(s):  
Ride Comfort ◽  
Vertical Vibration ◽  
Theoretical Research ◽  
Railway Vehicle ◽  
Vertical Acceleration ◽  
Damping Force ◽  
Comfort Index ◽  
Lateral Vibrations ◽  
Power Spectral ◽  
Vertical Vibrations

The theoretical research on means to reduce the vertical vibrations and improve the ride comfort of the railway vehicle relies on a mechanical model obtained from the simplified representation of the vehicle, while considering the important factors and elements affecting the vibration behaviour of the carbody. One of these elements is the anti-yaw damper, mounted longitudinally, between the bogie and the vehicle carbody. The anti-yaw damper reduces the lateral vibrations and inhibits the yaw motion of the vehicle, a reason for which this element is not usually introduced in the vehicle model when studying the vertical vibrations. Nevertheless, due to the position of the clamping points of the anti-yaw damper onto the carbody and the bogie, the damping force is generated not only in the yawing direction but also in the vertical and longitudinal directions. These forces act upon the vehicle carbody, impacting its vertical vibration behaviour. The paper analyzes the effect of the anti-winding damper on the vertical vibrations of the railway vehicle carbody and the ride comfort, based on the results derived from the numerical simulations. They highlight the influence of the damping, stiffness and the damper mounting angle on the power spectral density of the carbody vertical acceleration and the ride comfort index.

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.

Gain-Scheduled Two-Loop Autopilot for an Aircraft

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Laleh Ravanbod ◽  
Dominikus Noll
Keyword(s):  
Nonlinear Systems ◽  
Flight Control ◽  
New Method ◽  
Optimal Controller ◽  
Control Law ◽  
Vertical Acceleration ◽  
Operational Conditions ◽  
Gain Scheduled

We present a new method to compute output gain-scheduled controllers for nonlinear systems. We use structured H∞-control to precompute an optimal controller parametrization as a reference. We then propose three practical methods to implement a control law which has only an acceptable loss of performance with regard to the optimal reference law. Our method is demonstrated in longitudinal flight control, where the dynamics of the aircraft depend on the operational conditions velocity and altitude. We design a structured controller consisting of a PI-block to control vertical acceleration, and another I-block to control the pitch rate.

A Shaker Rig-Based Testing of Perceived Ride Comfort for Various Configurations of Active Suspensions

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Ivan Cvok ◽  
Mario Hrgetić ◽  
Joško Deur ◽  
Davor Hrovat ◽  
H. Eric Tseng
Keyword(s):  
Vehicle Dynamics ◽  
Autonomous Vehicles ◽  
High Performance ◽  
Ride Comfort ◽  
Optimal Controls ◽  
Subjective Measures ◽  
Preview Control ◽  
Active Suspensions ◽  
Driving Experience ◽  
Reading And Writing

Abstract Benefits of introducing active suspension in autonomous vehicles in terms of improving the driver's work/leisure ability can be tested under laboratory conditions using a high-performance shaker rig. In this paper, five different suspension configurations, including passive, semi-active, and fully active suspensions (FAS) and related optimal controls with or without road preview information, are implemented in vehicle dynamics simulator. They are experimentally examined having the driver in the loop to obtain objective and subjective measures of ride comfort and ability to do certain tasks. In total, 44 drivers of various age, gender, and driving experience performed three different tasks while being driven on shaker-rig (reading and writing, drawing, and subjective grading). The examination results show that FAS with road preview control offers highest ride comfort improvement, which can be perceived by the driver and greatly improves his/her ability to text and particularly draw.

Parametric Identification of Vehicle’s Vertical Dynamics Using Vector Autoregressive Moving Average Models

2006 ◽  
Author(s):  
Dimitris V. Koulocheris ◽  
Vasilis K. Dertimanis
Keyword(s):  
Ride Comfort ◽  
Moving Average ◽  
Estimation Procedure ◽  
Parametric Identification ◽  
Practical Implementation ◽  
Vertical Acceleration ◽  
Vector Autoregressive ◽  
Control Units ◽  
Conflicting Objectives ◽  
The Stability

The assessment of vertical dynamics in modern ground vehicles is a difficult task with crucial importance, as it appears to be possessed by a number of conflicting objectives, such as ride comfort and stability. Thus, the effective use of possible control units is depended by the successful description of the vertical performance. The aim of this study is to provide a closed description of vehicles’ vertical dynamics using VARMA models, which are estimated by means of a novel, hybrid optimization algorithm and a corresponding estimation procedure. The hybrid algorithm interconnects the diverse characteristics of its deterministic and stochastic counterparts, while the estimation procedure assures the stability and invertibility requirements in the resulted models. For the practical implementation of the above, a five dimensional VARMA model is used for the description of a passenger vehicle, through the acquisition of noise–corrupted vertical acceleration measurements.

scholarly journals On the Benefits of Semi-Active Suspensions with Inerters

2012 ◽  
Vol 19 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Xin-Jie Zhang ◽  
Mehdi Ahmadian ◽  
Kong-Hui Guo
Keyword(s):  
High Performance ◽  
Control Method ◽  
Hybrid Control ◽  
Active Suspension ◽  
Vertical Acceleration ◽  
Active Suspensions ◽  
Quarter Car Model ◽  
Suspension Systems ◽  
Car Model ◽  
Quarter Car

Inerters have become a hot topic in recent years especially in vehicle, train, building suspension systems, etc. Eight different layouts of suspensions were analyzed with a quarter-car model in this paper. Dimensionless root mean square (RMS) responses of the sprung mass vertical acceleration, the suspension travel, and the tire deflection are derived which were used to evaluate the performance of the quarter-car model. The behaviour of semi-active suspensions with inerters using Groundhook, Skyhook, and Hybrid control has been evaluated and compared to the performance of passive suspensions with inerters. Sensitivity analysis was applied to the development of a high performance semi-active suspension with an inerter. Numerical simulations indicate that a semi-active suspension with an inerter has much better performance than the passive suspension with an inerter, especially with the Hybrid control method, which has the best compromise between comfort and road holding quality.

Ride Comfort of Five-Axle Tractor/Semi-Trailer

2000 ◽  
Author(s):  
Zhenyu Jiang ◽  
Moustafa El-Gindy ◽  
Donald Streit
Keyword(s):  
Ride Comfort ◽  
General Concept ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
Gaussian Random Process ◽  
Long Distance ◽  
Power Spectral ◽  
Road Profile ◽  
Computer Based ◽  
Simulation Results

Abstract The issue of ride comfort for vehicle operations has recently generated considerable interest especially in heavy vehicle systems since long-distance drivers are more likely to experience high levels of vibration. This paper introduces the general concept of vibration-related health problems, discusses ride comfort assessment criteria and methods, and then focuses on the methodology of using computer simulation to analyze ride comfort. The computer-based ride comfort model can be divided into three sub-models: vehicle model, driver/seat model, and road profile input model. Several vehicle models and driver/seat models are reviewed and detailed modeling techniques are introduced. A five-axle tractor/semi-trailer/driver combination ride comfort simulation model is developed in this paper using the software DADS. Both four-spring tandem suspension and independent air spring suspension are studied. Road profiles are assumed as static zero mean Gaussian random process. Vertical acceleration at the interface between seat and driver body is obtained from simulation results. Power spectral density and root mean square (RMS) vertical acceleration are calculated based on simulation results. RMS acceleration at ISO classified good and average roads are compared with ISO 8-hour fatigue vibration limit. It is found that RMS acceleration of this particular vehicle simulated in this paper is below the ISO 8-hour fatigue limit for both good and average roads when traveling at the speed of fifty miles per hour. This implies a good ride comfort. Axle dynamic load coefficients (DLC) are calculated for four suspension configurations that are combinations of air springs and steel springs. Results show that large DLC doesn’t necessarily indicate bad ride quality.

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