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Viewing 1 to 14 of 14
2017-03-28
Journal Article
2017-01-0412
Mina M.S. Kaldas, Kemal Çalışkan, Roman Henze, Ferit Küçükay
Abstract Semi-active suspension offers variety of damping force range which demands greater need to optimize the top mount to ensure multiple objectives of ride comfort, harshness and safety can be achieved. For this purpose, this paper proposes a numerical optimization procedure for improving the harshness performance of the vehicle through the adjustment of the damper top mount characteristics of the semi-active suspension system. The proposed optimization process employs a frequency dependent combined objective function based on ride comfort and harshness evaluation. A detailed and accurate damper top mount mathematical model is implemented inside a validated full vehicle model to provide a realistic simulation environment for the optimization study. The semi-active suspension system employs a Rule-Optimized Fuzzy-Logic controller. The ride comfort and harshness of the full vehicle are evaluated by analyzing the body acceleration in different frequency ranges.
2016-09-02
Journal Article
2016-01-9112
Johannes Grau, Christoph Nippold, Bastian Bossdorf-Zimmer, Roman Henze, Ferit Küçükay
Abstract Electric power steering systems (EPS) are characterized by high inertia and therefore by a considerably damped transmission behaviour. While this is desirable for comfort-oriented designs, EPS do not provide enough feedback of the driving conditions, especially for drivers with a sporty driving style. The systematic actuation of the electric motor of an EPS makes it possible to specifically increment the intensity of the response. In this context, the road-sided induced forces of the tie rod and the steering rack force provide all the information for the steering system’s response. Former concepts differentiate between use and disturbance information by defining frequency ranges. Since these ranges overlap strongly, this differentiation does not segment distinctively. The presented article describes a method to identify useful information in the feedback path of the steering system depending on the driving situation.
2014-04-01
Technical Paper
2014-01-1909
Rashad Mustafa, Mirko Schulze, Peter Eilts, Ferit Küçükay
Abstract Hybrid electric vehicles (HEV's) are facing increasing challenges in optimizing the energy flow through a vehicle system, in order to improve both fuel economy and vehicle emissions. Energy management of HEV's is a difficult task due to the complexity of the total system in terms of electrical, mechanical and thermal behavior. In this paper, an advanced control strategy for a parallel hybrid vehicle is developed. Four main steps are presented, particularly to achieve a reduction in fuel consumption. The first step is the development of a highly complex HEV model, including dynamic and thermal behavior. Second, a heuristical control strategy is developed to determine the HEV modes and third, a State of Charge (SoC) leveling is developed with the interaction of a fuzzy logic controller. It is proposed to calculate the load point shifting of the Internal Combustion Engine (ICE) and the desired battery SoC.
2014-04-01
Journal Article
2014-01-0868
Mina Kaldas, Kemal Caliskan, Roman Henze, Ferit Küçükay
Abstract New developments in road profile measurement systems and in semi-active damper technology promote the application of preview control strategies to vehicle suspension systems. This paper details a new semi-active suspension control approach in which a rule-optimized Fuzzy Logic controller is enhanced through preview capability. The proposed approach utilizes an optimization process for obtaining the optimum membership functions and the optimum rule-base of the preview enhanced Fuzzy Logic controller. The preview enhanced Fuzzy Logic controller uses the feedforward road input information and the feedback vehicle state information as the controller inputs. An eleven degree of freedom full vehicle model, which is validated through laboratory tests performed on a hydraulic four-poster shaker, is used for the controller synthesis.
2014-04-01
Journal Article
2014-01-1804
Mirko Schulze, Rashad Mustafa, Benjamin Tilch, Peter Eilts, Ferit Küçükay
Hybrid electric vehicles (HEVs) are facing increased challenges of optimizing the energy flow through a vehicle system, to enhance both the fuel economy and emissions. Energy management of HEVs is a difficult task due to complexity of total system, considering the electrical, mechanical and thermal behavior. Innovative thermal management is one of the solutions for reaching these targets. In this paper, the potential of thermal management for a parallel HEV with a baseline control strategy under different driving cycles and ambient temperatures is presented. The focus of the investigations is on reducing fuel consumption and increasing comfort for passengers. In the first part of this paper, the developed HEV-model including the validation with measurements is presented. In the second part, the combined thermal management measures, for example the recuperation of exhaust-gas energy, engine compartment encapsulation and the effect on the target functions are discussed.
2013-04-08
Journal Article
2013-01-0340
Mohammad Adhitya, Rashad Mustafa, Artur Plötner, Ferit Küçükay
In this paper, a new gear preselect strategy of wet dual clutch transmission (DCT) is proposed by delaying the gear preselect to the time near the power shift time in order to create a seamless gear preselect. Software in the loop (SiL) method is used to investigate the proposed strategy. High fidelity 13 degree of freedom lumped inertia drivetrain models, i.e., synchronizer model and electro hydraulic model, are constructed and validated using laboratory test data. A closed loop control for electro hydraulic system is developed to control the clutch and synchronizer considering the optimum synchronizer trigger time. Furthermore, the model used in this study is constructed considering the valve spool dynamic in electro hydraulic system and the sleeve dynamic including axial drag force in synchronizer system. The genetic algorithm has been used to obtain the optimum trigger time which is close to the power shift time to sustain uninterrupted torque during gear shifting.
2013-04-08
Journal Article
2013-01-0991
Mina M.S. Kaldas, Kemal Çalışkan, Roman Henze, Ferit Küçükay
This paper presents a new and effective control concept for semi-active suspension systems. The proposed controller uses a Fuzzy Logic scheme which offers new opportunities in the improvement of vehicle ride performance. The Fuzzy Logic scheme tunes the controller to treat the conflict requirements of ride comfort and road holding parameters within a specified range of the suspension deflection. An eleven degree of freedom full vehicle ride dynamics model is constructed and validated through laboratory tests performed on a hydraulic four-poster shaker. A new optimization process for obtaining the optimum Fuzzy Logic membership functions and the optimum rule-base of the proposed semi-active suspension controller is proposed. Discrete optimization has been performed with a Genetic Algorithm (GA) to find the global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle.
2013-04-08
Technical Paper
2013-01-0574
Tinghui Hu, Kathrien Inderwisch, Rashad Mustafa, Ferit Küçükay
Hybrid electric vehicle (HEVs) represents a promising approach to reduce vehicle fuel consumption and exhaust emissions. However, due to the electric motor (EM) assistance, the engine load could be reduced and intermittent operation of engine is realizable in HEVs powertrain system. Consequently, the HEV powertrain heating-up process and engine fuel consumption will be changed accordingly. Therefore, the influences of the EM power and battery capacity on the hybrid powertrain heating-up process and the engine fuel consumption will be analyzed, and 2 methods for optimizing the heating-up process by applying the auxiliary heaters (AHs) and the modification of the energy management strategy are represented. The application of AHs can improve engine efficiency during heating-up; the controlling of the power flow from the AHs to the ICE cooling system is of special important.
2012-04-16
Journal Article
2012-01-1203
Rashad Mustafa, Mirko Schulze, Peter Eilts, Ferit Küçükay, Tobias Jaeckel, Christoph Lund
A vehicle thermal management system is required to increase the operating efficiency of components, to transfer the heat efficiently and to reduce the energy required for the vehicle. Vehicle thermal management technologies, such as engine compartment encapsulation together with grille shutter control, enable energy efficiency improvements through utilizing waste heat in the engine compartment for heating powertrain components as well as cabin heating and reducing the aerodynamic drag . In this work, a significant effort is put on recovering waste heat from the engine compartment to provide additional efficiency to the components using a motor compartment insulation technique and grille shutter. The tests are accelerated and the cost is reduced using a co-simulation tool based on high resolution, complex thermal and kinematics models. The results are validated with experimental values measured in a thermal wind tunnel, which provided satisfactory accuracy.
2012-04-16
Journal Article
2012-01-0054
Mina M.S. Kaldas, Kemal Çalışkan, Roman Henze, Ferit Küçükay
The current paper addresses the relationship between the damper top mount characteristics and the ride comfort and harshness of a vehicle. A detailed mathematical damper top mount model which can simulate the vertical force characteristics of damper top mounts is developed and verified with actual tests. The amplitude and frequency dependent parameters of the damper top mount model are extracted from experimental testing of a commercial damper top mount. In order to identify the model parameters, a new procedure based on a two-stage optimization routine using two sets of measurement data for the amplitude and frequency dependent parameters is proposed. The damper top mount model is validated by comparing the measured force of the damper top mount with the simulated force of the proposed model. The developed top mount model is then implemented into a quarter vehicle simulation model for studying the influence of damper top mount characteristics on vehicle ride comfort and harshness.
2012-04-16
Technical Paper
2012-01-0110
Rashad Mustafa, Ferit Küçükay
Powertrain control strategies achieving high performance and better shift control depend critically on the available measurements taken directly from the sensors. For Dual Clutch Transmission (DCT), the clutch friction forces are very important to improve the shift quality. So the estimations are needed to be able to set up the shift control on the powertrain system. For better shift comfort, accurate information for the dual clutch transmission should be available to control the clutch pressure. Furthermore, torque sensors for rotating shafts cannot be used on production vehicles since they are expensive and enduring in the environment of the automotive system. This paper presents an Improved Proportional Integral (IPI) observer for estimation of the unknown forces acting on the clutch during shift processes as well as the non measured states. The estimated unknown forces can be used for the closed-loop control of the dual clutch transmission for better shift quality.
2012-04-16
Technical Paper
2012-01-0311
Gerrit M Knabe, Ferit Küçükay
Current innovations in the area of power train engineering for cars are generating significant and unprecedented challenges for the development of acoustically unobtrusive transmissions. As regards relevance for customers, noise phenomena caused by loose parts play a key role. Transmission rattle, whose primary trigger is the pulse-like torque output of conventional combustion engines, also falls into this category. Current trends within the engine development (e.g. down speeding and downsizing) generate significant challenges for the development of acoustically unobtrusive transmissions. The aim of the presented approach is the evaluation and optimization of transmissions regarding the gear rattling noise perceived by the customer/passenger inside the vehicle. The investigation is divided into several experimental parts. The sound characteristics of the perceivable rattling noise is determined and evaluated as well as the transfer of rattling noise into the passenger compartment.
2011-04-12
Journal Article
2011-01-0437
Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
Due to the importance of the fast transportation under every circumstance, the transportation process may require a high speed heavy vehicle from time to time, which may turn the transportation process more unsafe. Due to that fact the truck safety during braking and the ride comfort during long distance travelling with high speeds should be improved. Therefore, the aim of this work is to develop a control system which combines the suspension and braking systems. The control system consists of three controllers; the first one for the active suspension system of the truck body and cab, the second one for the ABS and, the third for the integrated control system between the active suspension system and the ABS. The control strategy is also separated into two strategies.
2011-04-12
Journal Article
2011-01-0431
Mina M.S. Kaldas, Kemal Çalışkan, Roman Henze, Ferit Küçükay
Following the developments in controlled suspension system components, the studies on the vertical dynamics analysis of vehicles increased their popularity in recent years. The objective of this study is to develop a semi-active suspension system controller using Adaptive-Fuzzy Logic control theories together with Kalman Filter for state estimation. A quarter vehicle ride dynamics model is constructed and validated through laboratory tests performed on a hydraulic four-poster shaker. A Kalman Filter algorithm is constructed for bounce velocity estimation, and its accuracy is verified through measurements performed with external displacement sensors. The benefit of using adaptive control with Fuzzy-Logic to maintain the optimal performance over a wide range of road inputs is enhanced by the accuracy of Kalman Filter in estimating the controller inputs. A gradient-based optimization algorithm is applied for improving the Fuzzy-Logic controller parameters.
Viewing 1 to 14 of 14