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Reduction of the Effect of the Creep Groan Brake Excitation in a Comercial Vehicle

IDIADA Automotive Technology SA-Angel Sanchez
  • Technical Paper
  • 2020-01-1530
To be published on 2020-06-03 by SAE International in United States
One of the results generated by the stick-slip intermittent motion of a brake at the friction interface is the Creep Groan Noise which is a low frequency self-excited vibration, normally less than 220 Hz. This local vibration generated between the brake couple, is transmitted through the suspension system until the passengers of the vehicle in form of vibration and noise. This paper presents a methodology that combines testing and numerical models in order to 1) detect the source of the Creep Groan, 2) create a correlated numerical model and 3) produce countermeasures that reduce the amplitude of the noise at occupant positions. The vehicle under investigation was a commercial vehicle employing air-actuated brake drums. From testing, global vehicles modes and displacements under operational conditions were respectively investigated by means of Operational Deflection Shapes and Real Time Animation. These techniques allowed to prove the existence of a feedback loop with a positive gain that excites a suspension resonance mode, creating an unstable shaking effect in the whole vehicle. In-service data suggest that the brake actuation system…
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Sliding Mode Controlled Half Car Suspension System with Magnetorheological Damper

Anna University-AROCKIA SUTHAN SOOSAIRAJ, ARUNACHALAM K
  • Technical Paper
  • 2020-01-1540
To be published on 2020-06-03 by SAE International in United States
Attenuation of vibrations caused by the road undulance conditions are tedious and very much related to human health and vehicle handling problems. One of the promised approaches to solving these problems in a vehicle suspension system is the use of effective controllers. In this paper, the sliding mode controller (SMC) is designed and used to control the magnetorheological (MR) damper. The performance of the proposed controller is verified by incorporating the controller in a half car vehicle suspension model. In a suspension damper design, Modified Bouc-Wen model is used to characterize the hysteretic behaviour of MR damper parameters. The voltage control algorithm is used to convert the desired force into the varied voltage input to the MR damper. The fail-proof advantage of MR damper is analysed by comparing the results of uncontrolled MR suspension with a passive system. In order to limit the pitch angle and to achieve the improved ride comfort and stability of the vehicle, the vertical displacement of the front and rear body of the half-car model is controlled by the SMC…
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Characterisation of Brake Creep Groan Vibrations

Graz University of Technology-Peter Fischer, Manuel Pürscher, Severin Huemer-Kals
University of Ljubljana-Jurij Prezelj
  • Technical Paper
  • 2020-01-1505
To be published on 2020-06-03 by SAE International in United States
Creep Groan is an impulsive brake noise at very low velocities of the vehicle. Generally, stick-slip between brake disc and brake pads is assumed as the most dominating vibration mechanism of creep groan. This contribution will show by sophisticated measurement techniques, that stick-slip and speed dependent friction is an important trigger of this annoying vehicle noise. However, the overall vibration is much more complex than common stick-slip vibration models. It turns out, that in typical brake systems of passenger vehicles creep groan occurs around 15-20 Hz and 70-90 Hz. The mechanism at 15-20 Hz is an impulsive noise. Transitions between stick and slip phases trigger complex nonlinear vibrations of the complete brake and suspension system. At 70-90 Hz, the vibrations show a more harmonic-like behaviour, caused primarily by speed-dependent friction characteristics. Flexibilities in the suspension bushings, elastic deformations of suspension parts, wheel and tyre support the growth of instable self excited vibrations. In practical vehicle operation, the range of 70-90 Hz is the most relevant one. In many cases, the 15-20 Hz vibrations are not…
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Integrated Model Predictive Control and Adaptive Unscented Kalman Filter for Semi-Active Suspension System Based on Road Classification

China Automotive Technology and Research Center Co., Ltd.-Zhenfeng Wang, Shengjie Xu, Fei Li, Xinyu Wang, Jiansen Yang
Suzhou University of Science and Technology-Jing Miao
  • Technical Paper
  • 2020-01-0999
To be published on 2020-04-14 by SAE International in United States
The accuracy of state estimation and optimal control for controllable suspension system is a challenging task for the vehicle suspension system under various road excitations. How to effectively acquire suspension states and choose the reasonable control algorithm become a hot topic in both academia and industry. Uncertainty is unavoidable for the suspension system, e.g., varying sprung or unsprung mass, suspension damping force or spring stiffness. To tackle the above problems, a novel observer-based control approach, which combines adaptive unscented Kalman filter (AUKF) observer and model predictive control (MPC), is proposed in the paper. A quarter semi-active suspension nonlinear model and road profile model are first established. Secondly, using the road classification identification method based on system response, an AUKF algorithm is employed to estimate accurately the state of suspension system. Due to the nonlinear of semi-active suspension damping force in the movement process, the methods of observer-based and model predictive control are used to design the optimal predictive controller under various road excitations. Finally, compared with passive suspension system, the constrained optimal control (COC) algorithm…
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Design and Fabrication of Carbon Fibre/Epoxy-Aluminum Hybrid Suspension Control Arms for Formula SAE Race Cars

ARAI FID PUNE-Pramod Hande
Vellore Institute of Technology-Mayank Gupta, Akash Porwal, Harshvardhan Rao Budi, Padmanabhan Krishnan
  • Technical Paper
  • 2020-01-0230
To be published on 2020-04-14 by SAE International in United States
Suspension system of a vehicle plays an important role to carefully control motion of the wheel throughout the travel. The vertical and the lateral dynamics (ride and handling) is affected by the unsprung-to-sprung mass ratio. Lower value of this mass ratio leads to enhanced performance of the car. To optimize the unsprung mass of the car, design of control arm plate is optimized with Aluminum material and Carbon fibre reinforced composite control arms framework are used to achieve high stiffness to weight ratio. These leads to increase in overall power to weight ratio of the car which helps to deliver maximum performance to the wheels. Through analysis of real-life working conditions of the entire steering knuckle assembly in ACP pre- post ANSYS 18.1 with the defined boundary conditions, equivalent stress and total deformations are obtained. Based on the results, geometrical topology of the control arms plates is further optimized. After several tensile tests on different bond length and bond gap, the outer surface of control arm tube was bonded to the inner surface of control…
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PREDICTION OF SUSPENSION SYSTEM BEHAVIOR UNDER MISUSE LOADING USING EXPLICIT APPROACH

FCA Engineering India Pvt., Ltd.-Sameer Sudhakar Thakare, Sunil Kathoke, Kameshwara rao Appana
  • Technical Paper
  • 2020-01-1394
To be published on 2020-04-14 by SAE International in United States
Abstract: In the automotive industry, the development of suspension systems for misuse loads is essential. The vehicle may experience the abusive loads in fore-aft, lateral and vertical directions. From a design perspective, it is crucial that the suspension should be robust enough to withstand the abusive loading in different directions. Testing as well as virtual simulation of the suspension for feasible misuse scenarios can provide a desired design solution in the most optimized time. Better Virtual simulation practices provided with good modeling strategy and detail material model data can help to anticipate the accurate response of the system, which can benefit to reduce the number of physical tests. This paper describes an explicit dynamic approach to predict the behavior of suspension system under impact load condition. Material failure model is proposed to simulate the failure of parts and change in load path under high loading condition.
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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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Facility for Complete Characterization of Suspension Kinematic and Compliance Properties of Wheeled Military Vehicles

SEA, Ltd.-Dale Andreatta, Gary Heydinger, Anmol Sidhu, Scott Zagorski
  • Technical Paper
  • 2020-01-0175
To be published on 2020-04-14 by SAE International in United States
As part of their ongoing efforts to model and predict vehicle dynamics behavior, the US Army’s Ground Vehicle Systems Center procured a facility in two phases. The facility is called the Suspension Parameter Identification and Evaluation Rig (SPIdER) and has a capacity covering all of the military’s wheeled vehicles, with vehicle weights up to 100,000 lbs (45,400 kg), up to 150 inches wide, with any number of axles. The initial phase had the ability to measure bounce and roll kinematic and compliance properties. The SPIdER is the companion machine to the Vehicle Inertia Parameter Measuring Device (VIPER) which measures the inertia properties of vehicles of similar size. In 2015, the final phase of the SPIdER was completed. This phase includes ground plane wheel pad motion so that lateral, longitudinal, and aligning moment compliance and kinematic properties can be measured. These capabilities greatly enhance the SPIdER’s features, giving it the ability for making complete suspension and steering system kinematic and compliance measurements. Horizontal forces and aligning moments can be applied up to the limits of tire…
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Quantification of Clamp Loss and Subsequent Loosening of Automotive Hub-Knuckle Joints under Time-Varying Proving Ground Loading

FCA US LLC-Sandip Datta, Parag Nittur
  • Technical Paper
  • 2020-01-0181
To be published on 2020-04-14 by SAE International in United States
Threaded fasteners or bolted joints are used extensively in automotive assemblies. There are standard procedures to evaluate joint performance under block cycles or road loads. The deciding load case for such joint design is slippage analysis of the joint.There are studies done to evaluate the theoretical and experimental behavior of these joints. There are different ways of understanding the interaction between the bolt and the nut under different loading scenarios. However, none have provided a satisfactory method of quantifying bolt loosening or loss of clamp load under cyclic loading, where no slippage is observed.Under varying loads, initial relaxation of the joint is followed by a loss of clamping load. Below a critical value, complete loss of clamping load progresses very rapidly and this results in a loose joint. The loss of clamping load below the critical value happens at a transition stage when both elastic deformations of the bolt as well as external moments contribute to rapid loosening.This study provides an overall understanding of geometric parameters that contribute to sudden loss of clamping load and…