An Adaptive and Fast Control Strategy for Antilock Braking System

2015 ◽  
Author(s):  
S. Tajeddin ◽  
M. Batra ◽  
N. L. Azad ◽  
J. McPhee ◽  
R. A. Fraser
Keyword(s):  
Passenger Cars ◽  
The Road ◽  
Braking System ◽  
Antilock Braking System ◽  
New Strategy ◽  
Road Friction ◽  
Antilock Braking ◽  
And Performance ◽  
Road Characteristics ◽  
Abs Algorithm

After more than 30 years since the Antilock Braking System (ABS) was first introduced, it has become the most important active safety system used on passenger cars. However, it is hard to find a precise description of ABS, its stability and performance in the literature. Most of ABS algorithms currently used are not adaptive to changes of road friction conditions. The aim of our work is to provide a new ABS algorithm that is adaptive to changes of road conditions. To this end, an online parameter estimator is designed to estimate the road characteristics and maximum possible deceleration. Then, a driver demand regulator is proposed to limit the demanded deceleration to the maximum values. In this new strategy, road characteristics are estimated prior to the braking, not during the braking which makes it fast and adaptive. The proposed ABS algorithm is simulated on an artificial driving track and simulation results have been compared to a simple non-adaptive 6-phase Bosch ABS algorithm as our benchmark that is based on deceleration thresholds. Results show a better braking performance and more than 30% of reduction in braking distance.

Interaction of a Slip-Based Antilock Braking System with Tire Torsional Dynamics

2015 ◽  
Vol 43 (3) ◽  
pp. 182-194 ◽  
Author(s):  
Jeffery R. Anderson ◽  
John Adcox ◽  
Beshah Ayalew ◽  
Mike Knauff ◽  
Tim Rhyne ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Friction Model ◽  
Experimental Results ◽  
Braking Performance ◽  
Braking System ◽  
Lugre Friction Model ◽  
Antilock Braking System ◽  
Sensitivity Studies ◽  
Antilock Braking ◽  
Abs Algorithm

ABSTRACT This paper presents simulation and experimental results that outline the interaction between a tire's torsional dynamic properties and antilock braking system (ABS) during a hard braking event. Previous work has shown the importance of the coupled dynamics of the tire's belt, sidewall, and wheel/hub assembly on braking performance for a wheel acceleration-based ABS controller. This work presents findings based on a proprietary slip-based ABS controller. A comprehensive system model including tire torsional dynamics, dynamics of the tread–ground friction (LuGre friction model), and dominant brake system hydraulic dynamics was developed for simulation studies on this slip-based controller. Results from key sensitivity studies of tire torsional parameters are presented along with experimental results obtained on a quarter car braking test rig. In this work, it was found that within a reasonable tire design space (with respect to tire torsional properties), the ABS algorithm tested was extremely robust to changing these parameters. The main conclusion of this result is that when a consumer replaces his or her tires with different (than original equipment) tires, there should be little effect on braking performance.

Antilock Braking System Using Dynamic Speed Estimation

2015 ◽  
Vol 72 (2) ◽  
Author(s):  
Fargham Sandhu ◽  
Hazlina Selamat ◽  
Yahaya Md Sam
Keyword(s):  
Characteristic Function ◽  
Wheel Speed ◽  
Dominant Factor ◽  
The Road ◽  
Antilock Braking System ◽  
Switching Functions ◽  
Road Friction ◽  
Braking Distance ◽  
Antilock Braking ◽  
Proper Estimation

Antilock braking systems use slip to control braking, for which the velocity of the car and wheel speeds of the wheels are required. The wheel speeds can be measured directly but the velocity of the vehicle is difficult to measure. Although the wheel speed can be used to calculate the linear velocity of the vehicle using the tire characteristic function, it depends upon various environmental and time varying parameters. The dominant factor in the characteristic function is the road friction coefficient. Due to the difficulties in proper estimation of the road friction, most systems calculate the optimal values offline and apply them at different speeds using switching functions. By using the tire model and the optimal friction coefficients, the velocity of the vehicle is estimated and used for calculating the optimal braking force, resulting in inappropriate control of braking creating longer braking distances. In the method proposed in this paper, an estimator will be used to estimate the velocity, which is proved to be more accurate than calculated from the wheel speeds. The estimated velocity and the pitch angle will be used to schedule the braking forces in order to reduce the braking time. The braking time of the proposed system lies between the ideal braking time and the conventional reference wheel speed related braking time, indicating an improvement in reducing the braking distance.   

scholarly journals Design, Analysis and Application of Single-Wheel Test Bench for All-Electric Antilock Braking System in Electric Vehicles

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1294
Author(s):  
Xiangdang XUE ◽  
Ka Wai Eric CHENG ◽  
Wing Wa CHAN ◽  
Yat Chi FONG ◽  
Kin Lung Jerry KAN ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Test Bench ◽  
Potential Candidate ◽  
Vertical Force ◽  
Abs Algorithms ◽  
Braking System ◽  
Vehicle Velocity ◽  
Antilock Braking System ◽  
Antilock Braking ◽  
Electromechanical Brake

An antilock braking system (ABS) is one of the most important components in a road vehicle, which provides active protection during braking, to prevent the wheels from locking-up and achieve handling stability and steerability. The all-electric ABS without any hydraulic components is a potential candidate for electric vehicles. To demonstrate and examine the all-electric ABS algorithms, this article proposes a single-wheel all-electric ABS test bench, which mainly includes the vehicle wheel, the roller, the flywheels, and the electromechanical brake. To simulate dynamic operation of a real vehicle’s wheel, the kinetic energy of the total rotary components in the bench is designed to match the quarter of the one of a commercial car. The vertical force to the wheel is adjustable. The tire-roller contact simulates the real tire-road contact. The roller’s circumferential velocity represents the longitudinal vehicle velocity. The design and analysis of the proposed bench are described in detail. For the developed prototype, the rated clamping force of the electromechanical brake is 11 kN, the maximum vertical force to the wheel reaches 300 kg, and the maximum roller (vehicle) velocity reaches 100 km/h. The measurable bandwidth of the wheel speed is 4 Hz–2 kHz and the motor speed is 2.5 Hz–50 kHz. The measured results including the roller (vehicle) velocity, the wheel velocity, and the wheel slip are satisfactory. This article offers the effective tools to verify all-electric ABS algorithms in a laboratory, hence saving time and cost for the subsequent test on a real road.

Anti-Lock Wheel Slip Control With an Adaptive Searching Algorithm for the Optimal Slip

2015 ◽  
Author(s):  
Ning Pan ◽  
Liangyao Yu ◽  
Lei Zhang ◽  
Zhizhong Wang ◽  
Jian Song
Keyword(s):  
Lyapunov Theory ◽  
Modulation Amplitude ◽  
Wheel Slip ◽  
Slip Control ◽  
The Road ◽  
Road Friction ◽  
Speed Fluctuation ◽  
On The Road ◽  
Pressure Modulation ◽  
Abs Algorithm

An adaptive searching algorithm for the optimal slip during ABS wheel slip control is proposed. By taking advantage of the fluctuation of wheel slip control, the direction towards the optimal slip can be found, and the target slip calculated by the algorithm asymptotically converged to the optimal slip, which is proved using the Lyapunov theory. A gain-scheduling wheel slip controller is developed to control the wheel slip to the target slip. Simulations on the uniform road and on the road with changed friction are carried out to verify the effectiveness of the proposed algorithm. Simulation results show that the ABS algorithm using the proposed searching algorithm can make full use of the road friction and adapts to road friction changes. Comparing with the conventional rule-based ABS, the pressure modulation amplitude and wheel speed fluctuation is significantly reduced, improving control performance of ABS.

scholarly journals Simulation Study of the Process of Friction in the Working Elements of a Car Braking System at Different Degrees of Wear

2018 ◽  
Vol 12 (3) ◽  
pp. 221-226 ◽  
Author(s):  
Andrzej Borawski
Keyword(s):  
Simulation Study ◽  
Friction Pair ◽  
Experimental Studies ◽  
Real Life ◽  
Operating Conditions ◽  
Heating Process ◽  
Passenger Cars ◽  
The Road ◽  
Emergency Braking ◽  
Braking System

Abstract Among the many elements of a modern vehicle, the braking system is definitely among the most important ones. Health, and, frequently, life, may rest upon the design and reliability of brakes. The most common friction pair used in passenger cars today is a disc which rotates with the road wheel and a cooperating pair of brake pads. The composite material of the pad results in changing tribological properties as the pad wears, which was demonstrated in experimental studies. The change is also facilitated by the harsh operating conditions of brakes (high and rapid temperature changes, water, etc.). This paper looks into how changing tribology reflects on the heating process of disc and pads during braking. And so a simulation study was conducted, as this method makes it possible to measure temperature in any given point and at any time, which is either impossible or extremely difficult in real life conditions. Finite element method analyses were performed for emergency braking events at various initial speeds of the vehicle reflecting the current road speed limits.

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