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N&V Component Structural Integration and Mounted Component Durability Implications

General Motors LLC-Mark Stebbins, Joseph Schudt
  • Technical Paper
  • 2020-01-1396
To be published on 2020-04-14 by SAE International in United States
Exterior component integration has presented competing integration challenges for suitable exterior styling, safety, N&V structural feel and component durability balanced performances. Industry standard practice of N&V vehicle mode mapping uses vehicle source, path and receiver considerations for component mode frequency placement. Mounted component mode frequency performance can have an influence on structural feel and durability performances. Component integration headwinds have increased with additional nonstructural component styling content, component size, component mass and added sensor modules. Based on first principles, the effective mass of exterior mounted components are increased due to the geometric overhang from structure. Component input vibration levels are compounded due to the cantilevered nature as well as relative positioning to the suspension and propulsion vehicle source inputs locations. Examples of vehicle end mounted components include but are not limited to headlamps, side mirrors, end gates, bumpers and fascia. Our goal is to establish basic expectations for the behavior of these systems, and ultimately to consolidate our existing rational and approaches that can be applied to such integrated systems. The focus of this paper…
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Second-order sliding mode controller for performance analysis of Quarter car Magnetorheological suspension system

Anna University-Arockia Suthan Soosairaj, Arunachalam K
  • Technical Paper
  • 2020-01-1005
To be published on 2020-04-14 by SAE International in United States
To achieve the simultaneous improvement in ride comfort of the passenger as well as the stability of the vehicle, a second-order sliding mode controller is proposed in this study. Super twisting algorithm attenuates the chattering effect present in the conventional sliding mode controller without affecting the stability of the system. The Lyapunov stability analysis is carried out to verify the stability of the controller. The effectiveness of the designed super twisting algorithm used second-order sliding mode controller is validated in a semiactive quarter car suspension with seat model. Modified Bouc-wen magnetorheological (MR) damper model is used as a semiactive damper and the voltage that has to be supplied to the magnetorheological damper is controlled by a super twisting algorithm and sliding mode controller. Continuous modulation filtering algorithm is adopted to convert the force signal of a controller into the equivalent voltage input to the MR damper. The entire system is modelled in Matlab/Simulink software and the simulations are carried out based on random road disturbances. The results show that there is a significant improvement in…
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Vibration control of semi-active vehicle suspension system incorporating MR damper using fuzzy self-tuning PID approach

Helwan University-Ahmed Shehata Gad, W. Oraby, H. Metered
  • Technical Paper
  • 2020-01-1082
To be published on 2020-04-14 by SAE International in United States
In this paper, a nonlinear semi-active vehicle suspension system using MR fluid dampers is investigated to enhance ride comfort and vehicle stability. Fuzzy logic and fuzzy self-tuning PID control techniques are applied as system controllers to compute desired front and rear damping forces in conjunction with a Signum function method damper controller to assess force track-ability of system controllers. The suggested fuzzy self-tuning PID operates fuzzy system as a PID gains tuner to mitigate the vehicle vibration levels and achieve excellent performance related to ride comfort and vehicle stability. The equations of motion of four-degrees-of-freedom semi-active half-vehicle suspension system incorporating MR dampers are derived and simulated using Matlab/Simulink software. Control performance criteria including bounce and pitch motions are evaluated in both time and frequency domains in order to quantify the effectiveness of proposed system controllers under bump and random road disturbances. Fuzzy self-tuning PID controller gives a better force tracking than fuzzy logic. The performance of both controlled semi-active suspension systems using MR dampers is compared with MR passive and conventional passive to show the…
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Robust and optimum design selection for crank train dampers

Mahindra & Mahindra, Ltd.-Anup Bhattacharya, Vivek Yadav, Abhijit Londhe
  • Technical Paper
  • 2020-01-0603
To be published on 2020-04-14 by SAE International in United States
Reduced engine noise and vibrations is a key challenge in product development which leads to better comfort for end customer. Cranktrain is a major contributor in the transfer path of gas oscillations. The noise and vibrations induced by cranktrain torsional resonances are reduced by providing torsional dampers. Dampers are also important for avoiding resonant failures. The requirements from dampers is high reliability, lesser sensitivity for manufacturing variability in rubber properties with respect to desired performance. The requirement from a cranktrain damper is to achieve minimum crankshaft vibratory torque. Also, damper heat dissipation and torsional oscillations need to be within acceptable limits. This depends on selection of damper dimensions, damper hub inertia, ring inertia and rubber stiffness. There is a non-linear dependence of these parameters on damper performance. Hence, it needs an optimizer with better design space exploration capabilities. This paper presents, reliability based optimization process starting with generation of RSM followed by NSGA-II evolutionary search algorithm to achieve robust optimum damper design in early phase of product development through simulation. The process reduced number of…
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A Study on the Development of the CPA (Centrifugal Pendulum Absorber)Reducing the Rattle & Booming Noise in the Manual Transmission Vehicle

Ukjin Kim
  • Technical Paper
  • 2020-01-0397
To be published on 2020-04-14 by SAE International in United States
In recent years, the automotive engine strategies are forced on downsizing and down speeding to enhance fuel economy and reduce the emission. These make torque increase significantly in order to improve the vehicle performance, especially in diesel engines. At this time, the torsional damper performs the most important role in the driveline NVH of the manual transmission system. The clutch disk with torsional dampers is not easy to be applicable to the high torque of low speed RPM range. And DMF with sufficient isolation of vibrations of driving system includes disadvantages of the expensive cost, delayed response, and engine NVH aspect deteriorated due to increase of angular acceleration of engine. This paper presents that the Centrifugal Pendulum Absorber (CPA) is applied to maximize the isolation and to compensate for the disadvantages of DMF and SMF system. Furthermore, CPA was developed for the first time in the world on SMF clutch discs in manual transmission.
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Modelling of a combined system of hydraulic magnetorheological fluid damper with braking-by-wire system

Tsinghua University-Cenbo Xiong, Liangyao Yu, Zhenchuan Li, Zhenghong Lu, Abi Lanie
  • Technical Paper
  • 2020-01-0988
To be published on 2020-04-14 by SAE International in United States
A hydraulic chamber is embedded in serial with the accumulator of a normal mono-tube magnetorheological fluid damper (MRFD). The damper stiffness can be adjusted by changing the initial accumulator volume with the hydraulic chamber. This hydraulic chamber is connected to an electric pump and controlled by the braking-by-wire system. Some signals and control parameters of the braking system are shared with the suspension system. A modified bi-viscosity magnetorheological fluid (MRF) model that explicitly includes the parameter of control current is adopted to determine the viscous forces of the damper. A dynamic model of this hydraulic MRFD is subsequently set up based on the hydro dynamic system and the MRF model. In this scheme, both the MRF viscosity and the damper stiffness can be continuously adjusted at the same time. A theoretical model combining the vehicle dynamics, the braking-by-wire system and the hydraulic MRFD is established based on which the control principles of the hydraulic MRFD according to the braking intensity are revealed. Simulations are carried out to study the parametric influences of this combined braking…
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Multi-mode controller design for active seat suspension with energy-harvesting

Ebco Inc.-Peijun Xu
Huazhong University of Science and Technology-Zhenrui Zhang, Yunqing Zhang
  • Technical Paper
  • 2020-01-1083
To be published on 2020-04-14 by SAE International in United States
In this paper, a multi-mode active seat suspension with a single actuator is proposed and built. A one-DOF seat suspension system is modeled based on a quarter of commercial vehicle model with a DC motor and a gear reducer as the actuator. Aiming at improving ride comfort and reducing energy consumption, a multi-mode controller is presented. According to the seat vertical acceleration and suspension dynamic travel signals, control strategies switch among three modes: active drive mode, energy harvesting mode and plug breaking mode. In active drive mode, the DC motor works in the driving state and its output torque which calculated by LQR algorithm is controlled by a current-loop controller; in energy harvesting mode, the DC motor works in the generator state by which induced current can charge the power source, in this mode, the DC motor is considered as a damper which damping coefficient is decided by the charging current and controlled by Skyhook algorithm; in plug breaking mode, the DC motor works in the plug breaking state and its inverse voltage reaches to…
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A simulation study of rotating impact within a damper of torque converter

Valeo-Kapec-Zane Yang
  • Technical Paper
  • 2020-01-0500
To be published on 2020-04-14 by SAE International in United States
In a torque converter's damper, connected between an engine and transmission, it is very common that both angular velocities are generally not identical, because of the flexible elements. When the angular velocity of either engine output or transmission input abruptly changes, for example, as the result of driving conditions, an internal impact could occur between what is a primary member connected to the engine and secondary member connected to the transmission. From dynamics’ viewpoint, the impact loads are nothing but a response to huge inertial moment as the result of rapid acceleration or deceleration of rotating members involved. Depending on the duration of impact, it could lead to such a large internal moment that its magnitude could be several times the torque an engine’s combustion force can generate. Consequently, the impact load can be very devastating to a torque converter and other power-train members. This work presents a comprehensive and interesting study about the importance of understanding the rotational impact behavior. Using an explicit FEA solver for case studies, it will demonstrate that a clutch…
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ACOUSTC CHARACTERISTICS OF AUTOMOTIVE DAMPER DURING FLUID STRUCTURE AND STRUCTURAL INTERACTIONS

Gabriel India Ltd.-Ravi B
VIT ARAI-Swapnil S. Kulkarni
  • Technical Paper
  • 2020-01-0989
To be published on 2020-04-14 by SAE International in United States
Acoustic characteristics of hydraulic dampers used in passenger cars are investigated. Experimentation work is carried out with servo hydraulic machine. Semi-anechoic chamber is used to isolate damper, in order to study noise source in damper. Noise and vibration data analysis is performed with the help of OROS software which is specifically used for noise and vibration data acquisition and analysis. Noise and vibration tests are performed by various frequencies and amplitude excitation inputs given to damper. As a part of low to mid frequency excitation, the amplitude of damper excitation is 20 mm in rebound and 10 mm in compression stroke of damper with data contains multiple input frequencies namely 0.5, 1, 1.5, and 2 Hz. This test condition ensured that the noise is perceived to car cabin by means of damper rather than filtration unit attached to damper. As a part of high frequency excitation, damper is stroked at low amplitude and high frequency typically ±5 mm in rebound and compression stroke of damper, respectively where 5, 10 and 12 Hz are the input…
new

Crank-Lever Electromagnetic Damper (CLEMD) Design for Automobile Suspension System

SAE International Journal of Passenger Cars - Mechanical Systems

Politecnico Di Milano, Italy-Stefano Melzi
Veermata Jijabai Technological Institute, India-Prashant Eknath Todmal
  • Journal Article
  • 06-13-01-0002
Published 2020-02-04 by SAE International in United States
An effective damper is among the most important components of the suspension system. It ensures the right amount of damping force is acting on the suspension system to provide comfort to the passengers and proper road holding to tires. Unfortunately, the energy absorbed by the dampers from the suspension system gets wasted in the form of heat. In this article, it is proposed to use innovative electromagnetic damper (EMD) with a crank-lever mechanism to recover energy from the suspension system. The goal is to develop a lightweight design of EMD that can recover a high amount of power. For the design, an off-road vehicle is used since in off-road vehicles the amount of power wasted in the suspension system is high. Three different design approaches are used, which include single-stage gearbox type, two-stage gearbox type, and three-stage gearbox type of CLEMD. Out of them, the best design, i.e. three-stage gearbox type of CLEMD is selected because of minimum weight and inertia of the components. This article is focused on the design and analysis of the…