The brake system is one of the vital systems in an automobile that ensure its safety on the road. Air brake systems are usually used in commercial vehicle such as buses, trucks and tractor-trailers. The brake system should ideally operate with the least effort from the driver and should stop the vehicle within the shortest possible distance. The brake time lag and the brake response time are two important parameters that play a major role in determining the stopping distance. The conventional air brake system uses mechanically actuated valves that have an intrinsic time lag associated with them. An electro-pneumatic brake will use electronically actuated valves that will reduce the stopping distance of the vehicle by decreasing the time lag and the response time of the brake system. The work presented in this paper focuses on a comprehensive performance evaluation of an electro-pneumatic brake system in comparison with the conventional air brake system. This is carried out by performing exhaustive experiments and analyzing the collected data. The best configuration of the electro-pneumatic brake system is determined considering both system performance and system cost and complexity. © 2012 IEEE.

Shankar Coimbatore Subramanian

Department of Engineering Design

BRAKE RESPONSE TIME

Brake systems

COMPREHENSIVE PERFORMANCE EVALUATION

ELECTRO-PNEUMATIC BRAKING

ELECTROPNEUMATIC

STOPPING DISTANCE

TIME LAG

VITAL SYSTEMS

AIR BRAKES

Automobiles

Commercial vehicles

Control

Embedded systems

Light trailers

Pneumatic equipment

Pneumatics

Tractors (truck)

Response time (computer systems)

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Performance evaluation of an electro-pneumatic braking system for commercial vehicles

ICPCES 2012 - 2012 2nd International Conference on Power, Control and Embedded Systems

A rear-end collision avoidance system (RECAS) could reduce accidents by assisting drivers during emergencies through autonomous braking. If the decision to intervene is made too early, the intervention can become a disturbance to the driver and if the decision is made too late, the safety benefits of the system will be reduced. Hence, proper threat assessment is important to make a decision for intervention in a RECAS. In this study, a new threat assessment measure using a varying time headway has been proposed to develop a rear-end collision avoidance algorithm (RECAA) for heavy commercial road vehicles in heterogeneous traffic. The proposed varying time headway depends on the type of lead vehicle, host vehicle load conditions, road conditions and relative longitudinal speed. The developed RECAA was implemented in a hardware-in-loop experimental setup that is equipped with the vehicle dynamic simulation software, IPG/TruckMaker® and tested for vehicle following scenarios using different types of lead vehicles and host vehicle loading conditions. The results showed that the proposed varying time headway improved the RECAA by activating the host vehicle's brake system at different time instants based on the type of lead vehicle and thereby preventing the unintended early brake intervention of RECAS. © 2017 Elsevier Ltd

Mechatronics

Heavy vehicle collision avoidance control in heterogeneous traffic using varying time headway

Heavy commercial road vehicles have a longer stopping distance, owing to the inherent time lag associated with the conventional air brake system used in them. In general, electropneumatic brake systems would respond more quickly, resulting in a shorter stopping distance; these are the focus of this study. In an earlier work, the best configuration of the electropneumatic brake system was determined, considering both response and cost perspectives. This study focuses on the development of an experimentally corroborated mathematical model for this brake system. Non-linear model-based deceleration and brake chamber pressure control schemes were subsequently developed and their performance evaluated using a hardware-in-loop system. The model-based analysis and the control schemes presented in this article will assist in the development of advanced and cost-efficient active safety systems for heavy commercial road vehicles. © Institution of Mechanical Engineers.

Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering

Model-based braking control of a heavy commercial road vehicle equipped with an electropneumatic brake system

In this paper, a non-linear controller for collision avoidance in a heavy commercial road vehicle has been developed using Lyapunov theory. This paper considers the longitudinal dynamics of the vehicle, including the aerodynamic effect, the rolling resistance and the road grade. This paper also considers the maximum tire-road adhesion capacity and the braking capability of the vehicle. The developed controller has been tested using simulation for three realistic scenarios for different road and loading conditions and the results were compared with a controller developed using a linear full state feedback controller. It was observed that the non-linear controller has an advantage in terms of reduced time headway. © 2014 IEEE.

2014 IEEE International Conference on Vehicular Electronics and Safety, ICVES 2014

Comparison of linear and non-linear control schemes for collision avoidance in heavy road vehicles

The brake system is the primary system in an automobile which ensures its safety on the road. The ideal brake system should operate with the least effort from the driver and should stop the vehicle within the minimum possible distance. This paper deals with the air brake system which is widely used in commercial vehicles such as trucks, buses and tractor-trailers. One of the important parameters which affect the stopping distance of a vehicle is the brake response time. The work presented focuses on the development of an electropneumatic brake which would decrease the response time of the air brake system thereby providing a reduced stopping distance. A mathematical model that correlates the pressure transients in the brake chamber to the voltage input provided to the electropneumatic brake has been developed. The efficacy of this model is tested by comparing its results with experimental data obtained from various test runs. © 2009 IEEE.

Journal	ICPCES 2012 - 2012 2nd International Conference on Power, Control and Embedded Systems
Open Access	No