ADVANCED BRAKING SYSTEM CONTROL PROTOTYPING USING NETWORKED HARDWARE-IN-THE-LOOP TECHNIQUE

Control functions for the base-braking and emergency braking situations are important element of the vehicle active safety and have high requirements to robustness. The corresponding control algorithms should be reliable, provide sufficient level of system adaptiveness and be able to reject external disturbances. This demands not only the well-organized controller from the theoretical point of view, but also its systematic experimental validation. Moreover, effects and factors, which can potentially produce deterioration of braking system control functions, should be properly taken into account in the simulation and during the experiments. Another important factor is that brake control systems have a closed-loop operation with the tyre-road interaction, and its operation is accompanied by such complex effects like (i) variation of disc/pad friction coefficient and (ii) brake hysteresis. This produces strong demand on extension of the conventional testing facilities for the braking system control evaluation. Therefore, besides the part of the control system design, this paper represents possible advancement of hardware-in-the-loop testing procedure for development and validation of braking system control functions

Vision-based active safety system for automatic stopping

ntelligent systems designed to reduce highway fatalities have been widely applied in the automotive sector in the last decade. Of all users of transport systems, pedestrians are the most vulnerable in crashes as they are unprotected. This paper deals with an autonomous intelligent emergency system designed to avoid collisions with pedestrians. The system consists of a fuzzy controller based on the time-to-collision estimate – obtained via a vision-based system – and the wheel-locking probability – obtained via the vehicle’s CAN bus – that generates a safe braking action. The system has been tested in a real car – a convertible Citroën C3 Pluriel – equipped with an automated electro-hydraulic braking system capable of working in parallel with the vehicle’s original braking circuit. The system is used as a last resort in the case that an unexpected pedestrian is in the lane and all the warnings have failed to produce a response from the driver

Development of a Fuzzy Slip Control System for Electric Vehicles with In-wheel Motors

Replicated with permission by SAE Copyright © 2017 SAE International. Further distribution of this material is not permitted without prior permission from SAE.A two-passenger all-wheel drive urban electric vehicle (AUTO21EV) with four direct-drive in-wheel motors and an active steering system has been designed and developed at the University of Waterloo. A novel fuzzy slip control system is developed for this vehicle using the advantage of four in-wheel motors. A conventional slip control system uses the hydraulic brake system in order to control the tire slip ratio, which is the difference between the wheel center velocity and the velocity of the tire contact patch along the wheel plane, thereby influencing the longitudinal dynamics of a vehicle. The advantage of the proposed fuzzy slip controller is that it acts as an ABS system by preventing the tires from locking up when braking, as a TCS by preventing the tires from spinning out when accelerating. More importantly, the proposed slip controller is also capable of replacing the entire hydraulic brake system of the vehicle by automatically distributing the braking force between the wheels using the available braking torque of the in-wheel motors. In this regard, the proposed fuzzy slip controller guarantees the highest traction or braking force on each wheel on every road condition by individually controlling the slip ratio of each tire with a much faster response time. The performance of the proposed fuzzy slip controller is confirmed by driving the AUTO21EV through several test maneuvers using a driver model in the simulation environment. As the final step, the fuzzy slip controller is implemented in a hardware- and operator-in-the-loop driving simulator and its performance and effectiveness is confirmed.Funding for this work was provided by the Natural Sciences and Engineering Research Council of Canada(NSERC) and a grant from AUTO21, a Canadian Network of Centres of Excellence

Development and Validation of on-board systems control laws

Purpose - The purpose of this paper is to describe the tool and procedure developed in order to design the control laws of several UAV (Unmanned Aerial Vehicle) sub-systems. The authors designed and developed the logics governing: landing gear, nose wheel steering, wheel braking, and fuel system. Design/methodology/approach - This procedure is based on a general purpose, object-oriented, simulation tool. The development method used is based on three-steps. The main structure of the control laws is defined through flow charts; then the logics are ported to ANSI-C programming language; finally the code is implemented inside the status model. The status model is a Matlab-Simulink model, which uses an embedded Matlab-function to model the FCC (Flight Control Computer). The core block is linked with the components, but cannot access their internal model. Interfaces between FCCs and system components in the model reflect real system ones. Findings - The user verifies systems' reactions in real time, through the status model. Using block-oriented approach, development of the control laws and integration of several systems is faster. Practical implications - The tool aims to test and validate the control laws dynamically, helping specialists to find out odd logics or undesired responses, during the pre-design. Originality/value - The development team can test and verify the control laws in various failure scenarios. This tool allows more reliable and effective logics to be produced, which can be directly used on the system

A Hardware-in-the-Loop Facility for Integrated Vehicle Dynamics Control System Design and Validation

Due to the increased number and the complexity of the embedded systems in today’s vehicle, there is ever increasing pressure to reduce the development cost and time to market of such systems. In recent years, Model based Development (MBD) is becoming a main stream in the development of automotive embedded systems, and Hardware-in-the-Loop (HiL) testing is one of the key steps toward the implementation of MBD approach. This paper presents the recent HiL facility that has been developed at Cranfield University. The HiL setup includes real steering and brake smart actuator, high fidelity validated vehicle model, complete rapid control prototyping tool chain, and driver-in-the-loop capability. The applications of HiL setup are including but not limited to: smart actuators system identification; rapid control development and early validation of standalone and/or integrated vehicle dynamics control systems. Furthermore, the facility can be employed for investigation on driver-vehicle interaction at the presence of standalone active steering and/or brake systems as well as various Advanced Driver Assist Systems (ADAS), such as lane keeping or adaptive cruise control systems. The capability of the HiL facility for validation of a several newly developed vehicle dynamics control systems is presente

IMPROVED AUTOMOTIVE SAFETY THROUGH INSTRUCTIONAL MODULES AND AUTOMOTIVE DRIVING SIMULATOR BASED SKILLS TRAINING WITH ASSESSMENT

Motor vehicle crashes involving novice drivers are significantly higher than matured drivers\u27 incidents as reported by the National Highway Traffic Safety Administration Fatality Analysis Reporting System (NHTSA-FARS). There is ongoing research on how to decrease the number of crashes for this driver demographic group in the Unites States and Europe. Novice drivers usually complete driver education classes as a pre-requisite for full licensure to improve overall knowledge and safety. However, compiled statistics still indicate a need for more in-depth training after full licensure. This thesis introduces classroom and virtual training modules to improve the driving skills, attitudes, knowledge, and behavior of \u27high-risk\u27 young adult participants. The approach was to design two training modules for classroom instruction and establish a framework for a Public Service Announcement (PSA) seminar. In addition, a case study was performed using three automotive simulators exploring their potential use as a driver training resource. One of the driving simulators was subsequently used to complete a feasibility study examining the use of simulators as a driver training tool. The instructional modules covered vehicle maintenance, vehicle safety systems, and general automotive operations. The vehicle maintenance material included topics such as operating fluids, tires, brakes, windshield wipers, light bulbs, batteries, and warning lights. The second module focused on the basic operation of the vehicle and several key safety features (e.g., anti-lock braking system, electronic stability control, traction control system, seatbelts, and airbags). The PSA seminar introduced driving strategies such as avoiding driver distractions, seatbelt usage, and speed management using video campaigns produced by national and international organizations. Three simulators (DriveSafety Simulator, STISIM Drive Simulator, CU-Steering Simulator) were evaluated at North Carolina A&T University and Clemson University for their possible use in driver education programs. The overall performance was considered in nine general areas: ease of use, user-interface, motion/vision agreement, vehicle dynamics, haptic feedback, traffic scenarios, realism, mobility, and programmability. The DriveSafety simulator was determined the best option, since it provided the greatest number of characteristics ideally required for a training simulator. Based on the favorable results of this study, the opportunity to improve the driving skills of novice drivers using a DriveSafety automotive simulator was examined. Training test scripts for \u27Following Etiquette\u27 and \u27Situational Awareness\u27 were developed to introduce these key driving techniques. The training modules were administered in a pilot study using Clemson University students (ages 18-25). Students received little verbal instruction from the examiner; the majority of information was delivered by custom training videos and embedded driving simulator instructions. The \u27Following Etiquette\u27 module taught a basic timing method that allowed drivers to maintain a recommended following distance: 58% passed and 42% failed. The \u27Situational Awareness\u27 module allowed students to practice obstacle avoidance techniques and emergency maneuvers: 25% passed out right, 58% conditionally passed, and 17% failed. The classroom and virtual training modules were developed for possible implementation in a safe driving program. The automotive driving simulator proved to be a feasible option for facilitating automotive safety lessons, followed immediately by driving exercises to practice and reinforce the educational concept. Recommendations for additional classroom modules and virtual training modules are put forth for future study

The Application of Regenerative Braking System to the Commercial Hybrid Vehicles with All-Wheel Drive System

The growing issues of energy shortage and the environmental crisis has resulted in new challenges for the automotive industry. Conventional commercial vehicles, such as refuse trucks and delivery vehicles, consume significantly more energy than other on-road vehicles since they have the characteristic of frequent start/stop with high moment of inertia and drive at low speeds on designated city routes. It is important to make these vehicles more fuel efficient and environmentally friendly. The hybrid commercial vehicle is a promising solution to reduce emissions and to meet the future vehicle emission standard since it is generally equipped with braking energy regeneration systems to recover the kinematic loss from frequent braking. This paper introduces a type of all-wheel drive hybrid concept suggested by Dr. Leo Oriet; the new concept allows commercial vehicles to have a significant improvement in kinetic braking energy recovery without sacrificing braking safety. Without mechanical connection involved to transfer energy within the powertrain, greater powertrain efficiency can be achieved. The research is based on the all-wheel drive with a two-axles regenerative braking strategy and driveline control unit. The vehicle model and driveline control unit were executed using AVL CRUISE to demonstrate its reliable braking energy regeneration system, effective energy management and emission reduction. Finally, the power system and engine operating condition, as well as vehicle driving mode, were analyzed after simulation to ensure the whole powertrain component functions together with high efficiency and significant reliability

Compendium in Vehicle Motion Engineering

This compendium is written for the course “MMF062 Vehicle Motion Engineering” at Chalmers University of Technology. The compendium covers more than included in that course; both in terms of subsystem designs and in terms of some teasers for more advanced studies of vehicle dynamics. Therefore, it is also useful for the more advanced course “TME102 Vehicle Modelling and Control”.The overall objective of the compendium is to educate vehicle dynamists, i.e., engineers that understand and can contribute to development of good motion and energy functionality of vehicles. The compendium focuses on road vehicles, primarily passenger cars and commercial vehicles. Smaller road vehicles, such as bicycles and single-person cars, are only very briefly addressed. It should be mentioned that there exist a lot of ground-vehicle types not covered at all, such as: off-road/construction vehicles, tracked vehicles, horse wagons, hovercrafts, or railway vehicles.Functions are needed for requirement setting, design and verification. The overall order within the compendium is that models/methods/tools needed to understand each function are placed before the functions. Chapters 3-5 describes (complete vehicle) “functions”, organised after vehicle motion directions:\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 3:\ua0Longitudinal\ua0dynamics\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 4:\ua0Lateral\ua0dynamics\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 5:\ua0Vertical\ua0dynamicsChapter 1 introduces automotive industry and the overall way of working there and defines required pre-knowledge from “product-generic” engineering, e.g. modelling of dynamic systems.Chapter 2 also describes the subsystems relevant for vehicle dynamics:• Wheels and Tyre\ua0• Suspension\ua0• Propulsion\ua0• Braking System\ua0• Steering System\ua0• Environment Sensing Syste

Integrated braking control for electric vehicles with in-wheel propulsion and fully decoupled brake-by-wire system

This paper introduces a case study on the potential of new mechatronic chassis systems for battery electric vehicles, in this case a brake-by-wire (BBW) system and in-wheel propulsion on the rear axle combined with an integrated chassis control providing common safety features like anti-lock braking system (ABS), and enhanced functionalities, like torque blending. The presented controller was intended to also show the potential of continuous control strategies with regard to active safety, vehicle stability and driving comfort. Therefore, an integral sliding mode (ISM) and proportional integral (PI) control were used for wheel slip control (WSC) and benchmarked against each other and against classical used rule-based approach. The controller was realized in MatLab/Simulink and tested under real-time conditions in IPG CarMaker simulation environment for experimentally validated models of the target vehicle and its systems. The controller also contains robust observers for estimation of non-measurable vehicle states and parameters e.g., vehicle mass or road grade, which can have a significant influence on control performance and vehicle safety