Modelling and Development of Linear and Nonlinear Intelligent Controllers for Anti-lock Braking Systems (ABS)

 نظام  منع انغلاق المكابح (ABS)  يستخدم كجزء مهم في المركبات الحديثة لمنع الاطار من الغلق بعد تعشيق المكابح. الاداء العام لنظام سيطرة  منع انغلاق المكابح مستفيدا من كون النظام خطياً او غير خطي موضحاً في هذا البحث. من اجل تصميم نظام السيطرة، تم اشتقاق نموذج ديناميكي لاخطي لمانع الانزلاق استناداً على طبيعه نظامه الفيزيائي. النموذج الديناميكي متكون من عدة معادلات تحكم عمل النظام الميكانيكي.  نظامين سيطرة محتلفين تم استخدامهم للسيطرة على اداء  منع انغلاق المكابح، الاول تم الاستفادة من المسيطر الخطي نوع (PID) مع استخدام تقنية تحويل النظام من اللاخطي الى الخطي حول نقطة معينه للسيطرة على النظام اللاخطي. بينما تم استخدام المسيطر اللاخطي الثاني نوع (discrete time) للسيطرة على النظام الديناميكي اللاخطي بشكل مباشر. هذه الدراسة اعطت معلومات اضافية حول كيفية محاكاة هذين المسيطرين، و اعطت افضلية واضحة للمسيطر التقليدي (PID) على المسيطر نوع (discrete time) في السيطرة و التحكم بنظام منع انغلاق المكابح.Antilock braking systems (ABS) are utilized as a part of advanced autos to keep the vehicle’s wheels from deadlocking when the brakes are connected. The control performance of ABS utilizing linear and nonlinear controls is cleared up in this research. In order to design the control system of ABS a nonlinear dynamic model of the antilock braking systems is derived relying upon its physical system. The dynamic model contains set of equations valid for simulation and control of the mechanical framework. Two different controllers technique is proposed to control the behaviors of ABS. The first one utilized the PID controller with linearized technique around specific point to control the nonlinear system, while the second one used the nonlinear discrete time controller to control the nonlinear mathematical model directly. This investigation contributes to more additional information for the simulation of the two controllers, and demonstrates a clear and reasonable advantage of the classical PID controller on the nonlinear discrete time controller in control the antilock braking system

Modeling and control of antilock braking systems utilizing dynamic friction tire model

The development of high-performance antilock braking systems that provide reliability, steerability, and stability during braking in different road conditions, i.e., wet, icy or dry road surface, has attracted much attention in the automobile industry. This thesis addresses the controller designs for antilock braking systems (ABS) in vehicles. Simplified quarter vehicle models with special emphasis on the modeling of tire and dynamic tire-road interaction is utilized to develop and test the proposed controllers. The novelty of the present research is in the utilization and formulation of a new dynamic friction tire model for the development and testing of designed controller. Due to complex mechanics of tires, the dynamic friction tire model is significantly more realistic than that of commonly used static friction tire model. A detailed comparison of dynamic friction tire model with that of well-known magic formula and experimental data is carried out to demonstrate the effectiveness of the proposed formulation. Using this dynamic tire model, two methods for control of ABS system are proposed in this thesis, i.e., proportional-plus-integral (PI) control and the sliding mode control. Utilizing the PI controller design, the difficulty associated with on-line search of the optimal longitudinal slip can be easily overcome with the help of the dynamic friction tire model, which solves a commonly existed problem in the PI controller design. To show the advantage of the new dynamic tire model, a robust sliding mode control algorithm is also developed for the quarter vehicle model. The global stability of this control scheme is established by using the stability theory. Extensive simulation studies have been conducted for the developed controllers to demonstrate the effectiveness of the proposed control schemes. The investigation further demonstrates the effectiveness and convenience of utilizing dynamic friction tire model for the development of ABS controller

Tyre curve estimation in slip-controlled braking

Progress in reducing actuator delays in pneumatic brake systems creates an opportunity for advanced anti-lock braking algorithms to be used on heavy goods vehicles. However, these algorithms require knowledge of variables that are impractical to measure directly. This paper introduces a braking force observer and road surface identification algorithms to support a sliding-mode slip controller for air-braked heavy vehicles. Both the force observer and the slip controller are shown to operate robustly under a variety of conditions in quarter-car simulations. A non-linear least-squares algorithm was found to be capable of performing regressions on all the parameters of the tyre model from the University of Michigan Transportation Research Institute when used ‘in the loop’ with the controller and the observer. A recursive least-squares algorithm that is less computationally expensive than the non-linear algorithm was also investigated but gave only reasonable estimates of the tyre model parameters on high-friction smooth roads. The authors would like to thank the members of the Cambridge Vehicle Dynamics Consortium (CVDC), and the Gates Cambridge Trust for their parts in funding this work.This is the author accepted manuscript. The final version is available from Sage via http://dx.doi.org/10.1177/095440701558593

Full-scale testing of a novel slip control braking system for heavy vehicles

This paper summarises the measured emergency braking performance of a tri-axle heavy goods vehicle semitrailer fitted with a novel pneumatic slip control braking system developed by the Cambridge Vehicle Dynamics Consortium. Straight-line braking tests were carried out from 40 km/h in order to compare a commercially electro-pneumatic available anti-lock braking system and the Cambridge Vehicle Dynamics Consortium system, which has bi-stable valves coupled with a sliding-mode slip controller. On average, the Cambridge Vehicle Dynamics Consortium system reduced the stopping distance and the air use by 15% and 22% respectively compared with those for the conventional anti-lock braking system. The most significant improvements were seen on a wet basalt-tile surface (with similar friction properties to ice) where the stopping distance and the air use were improved by 17% and 30% respectively. A third performance metric, namely the mean absolute slip error, is introduced to quantify the ability of each braking system to track a wheel slip demand. Using this metric, the bi-stable valve system is shown to improve the wheel slip demand tracking by 62% compared with that of the conventional anti-lock braking system. This improvement potentially allows more accurate control of the wheel forces during extreme manoeuvres, providing scope for the future development of advanced stability control systems. This work was supported by Haldex Brake Products Ltd, the New Zealand Tertiary Education Commission and the Cambridge Vehicle Dynamics Consortium (CVDC).This is the author accepted manuscript. The final version is available from Sage via http://dx.doi.org/10.1177/095440701560480

Performance of Anti-Lock Braking Systems Based on Adaptive and Intelligent Control Methodologies

Automobiles of today must constantly change their speeds in reaction to changing road and traffic circumstances as the pace and density of road traffic increases. In sophisticated automobiles, the Anti-lock Braking System (ABS) is a vehicle safety system that enhances the vehicle's stability and steering capabilities by varying the torque to maintain the slip ratio at a safe level. This paper analyzes the performance of classical control, model reference adaptive control (MRAC), and intelligent control for controlling the (ABS). The ABS controller's goal is to keep the wheel slip ratio, which includes nonlinearities, parametric uncertainties, and disturbances as close to an optimal slip value as possible. This will decrease the stopping distance and guarantee safe vehicle operation during braking. A Bang-bang controller, PID, PID based Model Reference Adaptive Control (PID-MRAD), Fuzzy Logic Control (FLC), and Adaptive Neuro-Fuzzy Inference System (ANFIS) controller are used to control the vehicle model. The car was tested on a dry asphalt and ice road with only straight-line braking. Based on slip ratio, vehicle speed, angular velocity, and stopping time, comparisons are performed between all control strategies. To analyze braking characteristics, the simulation changes the road surface condition, vehicle weight, and control methods. The simulation results revealed that our objectives were met. The simulation results clearly show that the ANFIS provides more flexibility and improves system-tracking precision in control action compared to the Bang-bang, PID, PID-MRAC, and FLC

Self Tuning PID Control Of Antilock Braking System Using Electronic Wedge Brake

This paper describes the design of an antilock braking system (ABS) control for a passenger vehicle that employs an electronic wedge brake (EWB). The system is based on a two-degree-of-freedom (2-DOF) vehicle dynamic traction model, with the EWB acting as the brake actuator. The developed control structure, known as the Self-Tuning PID controller, is made up of a proportional-integral-derivative (PID) controller that serves as the main feedback loop control and a fuzzy supervisory system that serves as a tuner for the PID controller gains. This control structure is generated through two structures, namely FPID and SFPID, where the difference between these two structures is based on the fuzzy input used. An ABS-based PI D controller and a fuzzy fractional PID controller developed in previous works were used as the benchmark, as well as the testing method, to evaluate the effectiveness of the controller structure. According to the results of the tests, the performance of the SFPID controller is better than that of other PID and FPID controllers, being 10% and 1% faster in terms of stopping time, 8% and 1% shorter in terms of stopping distance, 9% and 1% faster in terms of settling time, and 40% and 5% more efficient in reaching the target slip, respectively

Study on effect of abs control system to the vehicle dynamic behavior during braking on various speed and road condition

The vehicle safety system is divided into two groups that are passive safety and active safety system. While a passive safety system’s purpose is to protect the occupant during an accident, an active safety system’s goal is to enable the vehicle to be controlled to avoid any collision. The passive safety system is a seatbelt, airbag, headrest, etc. Anti-lock Braking System (ABS) is one of many systems under the active safety system, a basic skid control system that can prevent the tire from locking up and enable the vehicle to steer during braking. Another active system is Forward Collision Warning (FCW), Electronic Stability Control (ESC), etc. Even with an active safety system, especially during emergency braking, the vehicle dynamic behavior may change abruptly, which can cause the vehicle to become unstable. The incident may be worse during emergency braking on the wet road condition. This study focuses on analyzing the vehicle dynamic behavior during emergency braking without and with ABS enabled in the system on dry and wet road conditions. The analysis of this study is divided into three phases; to investigate the vehicle dynamic behavior of the UMP test car (Proton Persona) during the braking experiment without ABS, development of the mathematical model of the vehicle and validation with the experimental result, and analyses of the simulation model with implementation of ABS. From the experimental results, on dry road conditions, all experiments conducted from an initial speed of 30 km/h, 50 km/h, and 60 km/h show no locking up occurred. While on wet road conditions, the lock-up condition is shown at front tires starting from the experiment at an initial speed of 50 km/h and 60 km/h. From experimental data, the mathematical model is simulated inside Matlab Simulink, and the model validation using RMSE is all under 10 % for vehicle speed, tire speed, stopping distance and slip ratio. With the addition of ABS inside the model, the simulation was repeated. Only on wet road condition is re-performed as on dry road condition there is no lock-up occur. With ABS enabled in the simulation, it is shown that the speed of all tires decreased gradually and no lock-up occurred. Thus, showing the modelling stay or lower than the optimum range of slip ratio used in the ABS. Additionally, the friction coefficient between the tire and the road was high, meaning the vehicle could be steered properly during braking. Data also shows shorter in both stopping time and stopping distance. The vertical forces also reduce periodically, showing the increase of vehicle stability. Furthermore, with the development of the mathematical model in this research, various ABS algorithms to improve the effectiveness of ABS on the vehicle can be done in future studies

Cooperative Control of Regenerative Braking and Antilock Braking for a Hybrid Electric Vehicle

A new cooperative braking control strategy (CBCS) is proposed for a parallel hybrid electric vehicle (HEV) with both a regenerative braking system and an antilock braking system (ABS) to achieve improved braking performance and energy regeneration. The braking system of the vehicle is based on a new method of HEV braking torque distribution that makes the antilock braking system work together with the regenerative braking system harmoniously. In the cooperative braking control strategy, a sliding mode controller (SMC) for ABS is designed to maintain the wheel slip within an optimal range by adjusting the hydraulic braking torque continuously; to reduce the chattering in SMC, a boundary-layer method with moderate tuning of a saturation function is also investigated; based on the wheel slip ratio, battery state of charge (SOC), and the motor speed, a fuzzy logic control strategy (FLC) is applied to adjust the regenerative braking torque dynamically. In order to evaluate the performance of the cooperative braking control strategy, the braking system model of a hybrid electric vehicle is built in MATLAB/SIMULINK. It is found from the simulation that the cooperative braking control strategy suggested in this paper provides satisfactory braking performance, passenger comfort, and high regenerative efficiency