Skyhook control strategy for vehicle suspensions based on the distribution of the operational conditions

2021 ◽  
pp. 095440702110065
Author(s):  
Georgios Papaioannou ◽  
Dimitrios Koulocheris ◽  
Efstathios Velenis
Keyword(s):  
Control Strategy ◽  
Performance Metrics ◽  
Ride Comfort ◽  
Damping Ratio ◽  
Cumulative Distribution ◽  
Operational Conditions ◽  
The Road ◽  
Vehicle Suspensions ◽  
Road Profile ◽  
The Impact

In this work, a novel distribution-based control strategy of semi-active vehicle suspensions is tested under different conditions. The novelty lies in the use of an appropriate threshold in the operational condition of the control algorithm, with which the operational conditions severity is quantified and the state of the damper is controlled according to the magnitude of the operational conditions and not their sign. The value of the threshold depends on the vibrations induced to the sprung mass by the road profile. In order to be evaluated, the operational conditions of the algorithm are fitted to a t-student distribution. The cumulative distribution function of this distribution is used in order to decrease the fraction of the sample operating with the damper’s stiff state. The strategy is applied to traditional SH control algorithms and is tested using a quarter car model excited by different road excitations. A sensitivity analysis for various threshold values is performed, investigating the impact of adopting the cumulative distribution functioned (CDF) controller to various performance metrics. The results illustrate an increase of up to 13% in the ride comfort of the passengers and increase of 6% in the road holding of the vehicle. Both are achieved by minimizing the switches of the damping ratio up to 80%.

scholarly journals Adaptive Hybrid Control of Vehicle Semiactive Suspension Based on Road Profile Estimation

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yechen Qin ◽  
Mingming Dong ◽  
Reza Langari ◽  
Liang Gu ◽  
Jifu Guan
Keyword(s):  
Control Strategy ◽  
Wavelet Transforms ◽  
Ride Comfort ◽  
Hybrid Control ◽  
Nsga Ii ◽  
Inference System ◽  
The Road ◽  
Road Profile ◽  
Adaptive Neurofuzzy Inference System ◽  
Profile Estimation

A new road estimation based suspension hybrid control strategy is proposed. Its aim is to adaptively change control gains to improve both ride comfort and road handling with the constraint of rattle space. To achieve this, analytical expressions for ride comfort, road handling, and rattle space with respect to road input are derived based on the hybrid control, and the problem is transformed into a MOOP (Multiobjective Optimization Problem) and has been solved by NSGA-II (Nondominated Sorting Genetic Algorithm-II). A new road estimation and classification method, which is based on ANFIS (Adaptive Neurofuzzy Inference System) and wavelet transforms, is then presented as a means of detecting the road profile level, and a Kalman filter is designed for observing unknown states. The results of simulations conducted with random road excitation show that the efficiency of the proposed control strategy compares favourably to that of a passive system.

Influence of the road profile accuracy on disturbance compensation in active suspension systems

2021 ◽  
Vol 69 (6) ◽  
pp. 485-498
Author(s):  
Felix Anhalt ◽  
Boris Lohmann
Keyword(s):  
Ride Comfort ◽  
Feedforward Control ◽  
Active Suspension ◽  
Disturbance Compensation ◽  
Critical Factors ◽  
The Road ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Road Profile ◽  
Profile Accuracy

Abstract By applying disturbance feedforward control in active suspension systems, knowledge of the road profile can be used to increase ride comfort and safety. As the assumed road profile will never match the real one perfectly, we examine the performance of different disturbance compensators under various deteriorations of the assumed road profile using both synthetic and measured profiles and two quarter vehicle models of different complexity. While a generally valid statement on the maximum tolerable deterioration cannot be made, we identify particularly critical factors and derive recommendations for practical use.

scholarly journals Multi-Objective Evaluation of Airborne Self-Separation Procedure in Flow Corridors Based on TOPSIS and Entropy

2019 ◽  
Vol 12 (1) ◽  
pp. 322 ◽  
Author(s):  
Bojia Ye ◽  
Zhao Yang ◽  
Lili Wan ◽  
Yunlong Dong
Keyword(s):  
Performance Metrics ◽  
Objective Evaluation ◽  
Entropy Method ◽  
Multiple Objectives ◽  
Separation Procedure ◽  
Traffic Operations ◽  
Agent Based ◽  
Operational Conditions ◽  
Simulation Based ◽  
The Impact

This paper proposes a simulation-based framework for assessing airborne self-separation procedures in flow corridors with consideration of different performance metrics, including air traffic operations, corridor capacity, safety, and environmental impacts. Firstly, the airborne self-separation concept in flow corridors is introduced, followed by an agent-based flow corridor simulation model. Then, data were collected to initialize a parallel-lane flow corridor model connecting A461 upper air route from Beijing to Guangzhou in China which can also simulate aircraft self-separating in the flow corridor. The total control delay, flow corridor throughput, breakout rate, and the CO2 emissions of traffic flow were considered as the impact measurements, and the TOPSIS and entropy method was used to rank the performances of different self-separation procedures. We found that combining multiple objectives into one, the optimum scheme can be obtained to guide the design of self-separation procedures for flow corridors. The research results can be used by airspace managers to dynamically develop appropriate operational procedures and rules for flow corridors given different operational conditions and constraints. Also, the framework proposed in the research may be used to evaluate the design of airspace structure with consideration of multiple objectives.

scholarly journals Electric Generator in the System for Damping Oscillations of Vehicles

2017 ◽  
Vol 54 (2) ◽  
pp. 3-13
Author(s):  
A. Serebryakov ◽  
E. Kamolins ◽  
N. Levin
Keyword(s):  
Power Generation ◽  
Ambient Temperature ◽  
Control Systems ◽  
Electric Energy ◽  
Electric Generator ◽  
Operational Conditions ◽  
The Road ◽  
Road Profile ◽  
Functional Efficiency ◽  
Linear Types

Abstract The control systems for the objects of industry, power generation, transport, etc. are extremely complicated; functional efficiency of these systems determines to a great extent the safe and non-polluting operation as well as convenience of service and repair of such objects. The authors consider the possibility to improve the efficiency of systems for damping oscillations in transport using a combination of electrical (generators of rotational and linear types) and hydraulic means. Better efficiency of functioning is achieved through automatic control over the operational conditions of such a system in order to make it adaptive to variations in the road profile and ambient temperature; besides, it is possible to produce additional electric energy.

Impact of Rayleigh-Distributed PAPR on the Performance of a Pre-Clipped DCO-OFDM System

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Jayashree Ratnam ◽  
Sabita Mali
Keyword(s):  
Power Efficiency ◽  
Performance Metrics ◽  
Scaling Factor ◽  
Cumulative Distribution ◽  
Weighted Estimate ◽  
Signal Power ◽  
Ofdm System ◽  
Optical Source ◽  
Ofdm Signal ◽  
The Impact

AbstractThe paper investigates the impact of Rayleigh-distributed statistical behavior of peak-to-average power ratio (PAPR) associated with a pre-clipped signal on the performance metrics of a direct current-biased optical orthogonal frequency division multiplexing (DCO-OFDM) system. The analytical model for the system takes into consideration a pre-clipped and dc-shifted baseband OFDM signal, driving an optical source over its linear operating range. The model employs a bias-scaling factor, which is heuristically varied over the entire range (0 to 1) to examine improvement in overall power efficiency. Further, it utilizes the cumulative distribution function (CDF) of the pre-clipped signal to get a weighted estimate of the available signal power within the clipped PAPR. The model also takes into consideration the clipping noise effects due to limited linearity of the optical source during electrical-to-optical conversion of baseband OFDM signal. Using this model, the paper aims to arrive at a realistic estimate of the system behavior in terms of bit error rate, electrical power-efficiency and spectral efficiency. Using theoretical simulation results, for a given set of operating parameters viz., signal power, PAPR, bias-scaling factor, modulation order and sub-carrier count, the paper examines the trade-offs involved in optimizing the performance metrics over appropriate dynamic range of the DCO-OFDM transmitter.

Handling and Primary Ride Comfort Development in Early Design Stage by Means of 1D Modeling Approach and Multi Attribute Optimization Process

2011 ◽  
Author(s):  
Stefano Alneri ◽  
Paolo di Carlo ◽  
Alessandro Toso ◽  
Stijn Donders
Keyword(s):  
Performance Metrics ◽  
Ride Comfort ◽  
Experimental Tests ◽  
Complex Model ◽  
Design Stage ◽  
Time Saving ◽  
Vehicle Performance ◽  
Early Design Stage ◽  
Automotive Market ◽  
The Impact

Today the automotive market is ever more competitive and vehicles must satisfy the requirements of the customers in all respects: handling, comfort, acoustics, fuel economy, etc. Therefore OEMs have to launch innovative products in a short development timeline: the time to market (TTM) of new vehicles has continually decreased and nowadays the developing process of a new car is completed in less years than in the past. This scenario emphasizes the role of CAE in the vehicle design engineering design and the necessity of exploiting its potentialities, in order to shorten the TTM and to reduce the impact of experimental tests on it. In this context a step-by-step approach with multi-physics 1D environment such as LMS Imagine. Lab AMESim is proposed in order to monitor vehicle performances in all the design stages, thanks to the employment of models with increasing complexity. In addition the ultimate step can be employed for performing a multi attribute optimization on vehicle performance metrics in order to find the best attributes balancing and to pass the preliminary recommendations to the design with a considerable time-saving respect to 3D MBS models. This paper briefly describes the process for building 1D models with LMS Imagine.Lab AMESim and moreover it shows the definition of a multi attribute optimization algorithm in terms of handling performances with the most complex model.

scholarly journals Vibration Control of Semi-Active Suspension System using Modified Skyhook with Advanced Firefly Algorithm

2021 ◽  
Vol 2129 (1) ◽  
pp. 012014
Author(s):  
M H Ab Talib ◽  
I Z Mat Darus ◽  
H M Yatim ◽  
M S Hadi ◽  
N M R Shaharuddin ◽  
...  
Keyword(s):  
Firefly Algorithm ◽  
Ride Comfort ◽  
Active Suspension ◽  
The Body ◽  
Matlab Simulation ◽  
The Road ◽  
Vehicle System ◽  
Road Profile ◽  
Control Scheme ◽  
Suspension Control

Abstract The semi-active suspension (SAS) system is a partial suspension device used in the vehicle system to improve the ride comfort and road handling. Due to the high non-linearity of the road profile disturbances plus uncertainties derived from vehicle dynamics, a conventional Skyhook controller is not deemed enough for the vehicle system to improve the performance. A major problem of the implementation of the controller is to optimize a proper parameter as this is an important element in demanding a good controller response. An advanced Firefly Algorithm (AFA) integrated with the modified skyhook (MSky) is proposed to enhance the robustness of the system and thus able to improve the vehicle ride comfort. In this paper, the controller scheme to be known as MSky-AFA was validated via MATLAB simulation environment. A different optimizer based on the original firefly algorithm (FA) is also studied in order to compute the parameter of the MSky controller. This control scheme to be known as MSky-FA was evaluated and compared to the proposed MSky-AFA as well as the passive suspension control. The results clearly exhibit more superior and better response of the MSky-AFA in reducing the body acceleration and displacement amplitude in comparison to the MSky-FA and passive counterparts for a sinusoidal road profile condition.

Body attitude control strategy based on road level for heavy rescue vehicles

2020 ◽  
pp. 095440702096616
Author(s):  
Hao Chen ◽  
Mingde Gong ◽  
Dingxuan Zhao ◽  
Jianxu Zhu
Keyword(s):  
Control Strategy ◽  
Attitude Control ◽  
Ride Comfort ◽  
Active Suspension ◽  
Suspension System ◽  
Vehicle Body ◽  
Vertical Acceleration ◽  
Inference System ◽  
The Road ◽  
Body Attitude

This paper proposes an attitude control strategy based on road level for heavy rescue vehicles. The strategy aims to address the problem of poor ride comfort and stability of heavy rescue vehicles in complex road conditions. Firstly, with the pressure of the suspension hydraulic cylinder chamber without a piston rod as the parameter, Takagi–Sugeno fuzzy controller classification and adaptive network-based fuzzy inference system controller classification are used to recognise the road level. Secondly, particle swarm optimisation is adopted to obtain the optimal parameters of the active suspension system of vehicle body attitude control under different road levels. Lastly, the parameters of the active suspension system are selected in accordance with the road level recognised in the driving process to improve the adaptive adjustment capability of the active suspension system at different road levels. Test results show that the root mean square values of vertical acceleration, pitch angle and roll angle of the vehicle body are reduced by 59.9%, 76.2% and 68.4%, respectively. This reduction improves the ride comfort and stability of heavy rescue vehicles in complex road conditions.

scholarly journals Classification Scheme for Random Longitudinal Road Unevenness Considering Road Waviness and Vehicle Response

2009 ◽  
Vol 16 (3) ◽  
pp. 273-289 ◽  
Author(s):  
Oldřich Kropáč ◽  
Peter Múčka
Keyword(s):  
Correction Factor ◽  
Ride Comfort ◽  
Vibration Response ◽  
Suitable Alternative ◽  
The Road ◽  
Novel Approach ◽  
Power Spectral ◽  
Road Profile ◽  
Basic Parameters ◽  
Single Number

A novel approach to the road unevenness classification based on the power spectral density with consideration of vehicle vibration response and broad interval of road waviness (road elevation PSD slope) is presented. This approach enables transformation of two basic parameters of road profile elevation PSD (unevenness index,C, and waviness,w) into a single-number indicatorCwwhen using a correction factorKwaccounting forw. For the road classification proposal two planar vehicle models (passenger car and truck), ten responses (reflecting ride comfort, dynamic load of road and cargo, ride safety) and three different vehicle velocities have been considered. The minimum of ten estimated vibration response ranges sum for a broad waviness interval typical for real road sections (w= 1.5 to 3.5) has been used for the correction factor estimation. The introduced unevenness indicator,Cw, reflects the vehicle vibration response and seems to be a suitable alternative to the other currently used single-number indicators or as an extension of the road classification according to the ISO 8608: 1995, which is based on constant waviness value,w= 2.

scholarly journals IMPACT OF THE ROAD PROFILE ON VEHICLE DECELERATION / IŠILGINIO KELIO PROFILIO ĮTAKA AUTOMOBILIO LĖTĖJIMO PAGREIČIUI

2012 ◽  
Vol 4 (4) ◽  
pp. 403-407
Author(s):  
Vidas Žuraulis
Keyword(s):  
Traffic Control ◽  
Traffic Accidents ◽  
Dynamic Properties ◽  
Theoretical Calculations ◽  
Technical Condition ◽  
The Road ◽  
Road Profile ◽  
Safety Parameters ◽  
On The Road ◽  
The Impact

The article analyzes the impact of the longitudinal road profile on the efficiency of car braking estimated applying deceleration value. Different formulas are used for theoretical calculations, and therefore experimental brakes in different road slopes were performed to obtain the most accurate results. Deceleration, as one of the most important safety parameters, depends on the technical condition of the braking system, road conditions and structural and dynamic properties of the other car. Road alignments can significantly affect car manageability, because of weight transfer and extra track resistance, which may change the overall balance of the car and affect the nature of dynamic characteristics that may vary from certain critical values. The results of corrections to deceleration dependence on the road profile can be used for investigating traffic accidents, optimizing traffic control arrangements and implementing advanced systems for automotive active safety. Santrauka Straipsnyje analizuojama kelio išilginio profilio įtaka automobilio stabdymo efektyvumui, kuris įvertinamas lėtėjimo pagreičio reikšme. Atliekant teorinius skaičiavimus taikomos skirtingos formulės, todėl siekiant gauti kuo tikslesnius rezultatus, buvo atliekami eksperimentiniai stabdymai skirtingo nuolydžio keliuose. Lėtėjimo pagreitis, kaip vienas svarbiausių eismo saugumo parametrų, priklauso nuo stabdžių sistemos techninės būklės, kelio sąlygų ir nuo kitų automobilio konstrukcinių ir dinaminių ypatybių. Išilginis kelio profilis gali gerokai paveikti automobilio valdomumą, nes vyksta svorio persislinkimas, atsiranda papildomos kelio varžos, dėl ko pasikeičia bendras automobilio balansas ir nuo tam tikrų kritinių reikšmių keičiasi dinaminių charakteristikų pobūdis. Patikslinus lėtėjimo pagreičio priklausomybę nuo išilginio kelio profilio, rezultatai gali būti pritaikomi tiriant eismo įvykius, optimizuojant eismo reguliavimo priemonių veikimą, diegiant pažangias automobilių aktyviosios saugos sistemas.

Sign in / Sign up

Export Citation Format

Share Document