Design and Hardware-In-Loop Implementation of Collision Avoidance Algorithms for Heavy Commercial Road Vehicles

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

Abstract: 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.

Effect of Vehicle-to-Vehicle Communication Latency on a Collision Avoidance Algorithm for Heavy Road Vehicles*

Abstract: Active safety is of utmost importance in heavy road vehicles due to the relatively higher number of fatalities encountered in their accidents. Vehicle-to-Vehicle (V2V) technology, which is seen as a future of connected vehicles, can potentially complement onboard sensing to reduce the time taken for detection, and to plan the path with the information available from road side units (RSU). This paper investigates the effect of Iatency in (V2V) communication on a collision avoidance algorithm developed for heavy road vehicles. Experiments performed on a Hardware-in-Loop (HiL) setup were used to evaluate the effect of Iatency for various scenarios. It was found that Iatency had a counterbalancing effect on vehicle spacing and relative longitudinal speed that led to insignificant changes in the final spacing. Further, a sensitivity analysis done at different host vehicle longitudinal speeds demonstrated the need of a variable time headway.

Vehicle braking force distribution with electronic pneumatic braking and hierarchical structure for commercial vehicle

Abstract: Brake by wire that allows a number of braking functions exists on commercial vehicles under the name electronic pneumatic braking system, which can improve braking comfort and safety of commercial ...

Research on a coordinated cornering brake control of three‐axle heavy vehicles based on hardware‐in‐loop test

Abstract: A direct yaw moment controller/anti-lock braking system (DYC/ABS) coordinated cornering brake control scheme is proposed for three-axle vehicles to improve the handling performance while shortening the brake distance. A proportional–integral method is designed in DYC control. The cornering stiffness of the two-degrees of freedom vehicle model is fitted in real time. The Dugoff tire model is used to establish the relationship between the yaw moment and wheel slip ratio; an optimal allocation method is proposed to allocate the force requirements to each tire. To verify the effect, vehicle responses under various speeds and turning radii are analysed with DYC/ABS coordinated control, ABS control, and no control based on co-simulation of TruckSim and MATLAB/Simulink. According to the chattering caused by sliding mode control, two sliding mode controllers using saturation function and modified exponential reaching law are, respectively, designed to obtain the braking moment in ABS control. A pneumatic braking hardware-in-loop (HIL) test system is developed; the effectiveness of the strategy is verified by experiments. The results show that the coordinated control can reduce lateral acceleration, brake distance, and brake time when the vehicle runs under cornering brake; thus has an excellent effect on balancing the handling stability and braking safety.

Path tracking control for inverse problem of vehicle handling dynamics

Abstract: A path tracking controller based on active disturbance rejection control(ADRC) theory is presented in this paper to solve path tracking problem in inverse vehicle handling dynamics. The basic idea behind the work is to design an active disturbance rejection controller according to yaw rate and lateral displacement during a vehicle travels along a prescribed path to generate an expected trajectory which guarantees minimum clearance to the prescribed path. Aiming at this purpose, using preview follower theory, a linear extended state observer based on lateral displacement is designed. Considering yaw angle of vehicle, a non-linear combination function combined error of lateral displacement as well as error of yaw angle is designed according to monotone bounded hyperbolic of tangent function. Finally, a real vehicle test is executed to verify the rationality of the path tracking controller. At the same time, according to characteristics of pavement file in Carsim, a 3-D virtual pavement model is established and ride comfort simulation of random pavement is carried out in the software model. The results show that the minimum lateral position error of the generated path tracking trajectory can be good indicators of successful solving of the path tracking problem in inverse vehicle handling dynamics for ADRC. More precisely, there is higher calculation accuracy for the algorithm of the ADRC to solve the path tracking problem. The study can help drivers easily identify safe lane-keeping trajectories and area.

Recursive least squares with forgetting for online estimation of vehicle mass and road grade: theory and experiments

Abstract: Good estimates of vehicle mass and road grade are important in automation of heavy duty vehicles, vehicle following manoeuvres or traditional powertrain control schemes. Recursive least square (RLS) with multiple forgetting factors accounts for different rates of change for different parameters and thus, enables simultaneous estimation of the time-varying grade and the piece-wise constant mass. An ad hoc modification of the update law for the gain in the RLS scheme is proposed and used in simulation and experiments. We demonstrate that the proposed scheme estimates mass within 5% of its actual value and tracks grade with good accuracy provided that inputs are persistently exciting. The experimental setups, signals, their source and their accuracy are discussed. Issues like lack of persistent excitations in certain parts of the run or difficulties of parameter tracking during gear shift are explained and suggestions to bypass these problems are made.

Brake design and safety

Abstract: The objectives of this third edition of an SAE classic title are to provide readers with the basic theoretical fundamentals and analytical tools necessary to design braking systems for passenger vehicles and trucks that comply with safety standards, minimize consumer complaints, and perform safely and efficiently before and while electronic brake controls become active. This book, written for students, engineers, forensic experts, and brake technicians, provides readers with theoretical knowledge of braking physics, and offers numerous illustrations and equations that make the information easy to understand and apply. New to this edition are expanded chapters on: • Thermal analysis of automotive brakes • Analysis of hydraulic brake systems • Single vehicle braking dynamics

Development of advanced driver assistance systems with vehicle hardware-in-the-loop simulations

Abstract: This paper presents a new method for the design and validation of advanced driver assistance systems (ADASs). With vehicle hardware-in-the-loop (VEHIL) simulations, the development process, and more specifically the validation phase, of intelligent vehicles is carried out safer, cheaper, and is more manageable. In the VEHIL laboratory, a full-scale ADAS-equipped vehicle is set up in a hardware-in-the-loop simulation environment, where a chassis dynamometer is used to emulate the road interaction and robot vehicles to represent other traffic. In this controlled environment, the performance and dependability of an ADAS is tested to great accuracy and reliability. The working principle and the added value of VEHIL are demonstrated with test results of an adaptive cruise control and a forward collision warning system. On the basis of the 'V' diagram, the position of VEHIL in the development process of ADASs is illustrated.

Development of a collision avoidance system

Abstract: The analysis of a rear-end collision warning/ avoidance (CW/CA) system algorithm will be presented. The system is designed to meet several criteria: 1. System warnings should result in a minimum load on driver attention. 2. Automatic control of the brakes should not interfere with normal driving operation.

Longitudinal control of the lead car of a platoon

Abstract: Presents longitudinal control laws for vehicles moving in an intelligent vehicle highway system (IVHS). In particular, the scenario where cars move along the highway in tightly spaced platoons is considered. The authors present control schemes that perform the major longitudinal tasks that will be required from the lead vehicle of a platoon moving on an automated highway. More specifically, schemes that maintain safe spacing, track an optimal velocity and perform various maneuvers (forming, breaking up platoons and changing lanes) are described. Simulation results are given. >