Anti-lock Braking System Control Research Articles

A Pressure-Coordinated Control for Vehicle Electro-Hydraulic Braking Systems

The characteristics of electro-hydraulic braking systems have a direct influence on the fuel consumption, emissions, brake safety, and ride comfort of hybrid electric vehicles. In order to realize efficient energy recovery for ensuring braking safety and considering that the existing electro-hydraulic braking pressure control systems have control complexity disadvantages and functional limitations, this study considers the front and rear dual-motor-driven hybrid electric vehicle as the prototype and based on antilock brake system (ABS) hardware, proposes a new braking pressure coordinated control system with electro-hydraulic braking function and developed a corresponding control strategy in order to realize efficient energy recovery and ensure braking safety, while considering the disadvantages of control complexity and functional limitations of existing electro-hydraulic system. The system satisfies the pressure coordinated control requirements of conventional braking, regenerative braking, and ABS braking. The vehicle dynamics model based on braking control strategy and pressure coordinated control system is established, and thereafter, the performance simulation of the vehicle-based pressure coordinated control system under typical braking conditions is carried out to validate the performance of the proposed system and control strategy. The simulation results show that the braking energy recovery rates under three different conditions—variable braking intensity, constant braking intensity and integrated braking model—are 66%, 55% and 47%. The battery state of charge (SOC) recovery rates are 0.37%, 0.31% and 0.36%. This proves that the motor can recover the reduced energy of the vehicle during braking and provide an appropriate braking force. It realizes the ABS control function and has good dynamic response and braking pressure control accuracy. The simulation results illustrate the effectiveness and feasibility of the program which lays the foundation for further design and optimization of the new regenerative braking system.

Adaptive fractional order fast terminal dynamic sliding mode controller design for antilock braking system (ABS)

This article focuses on designing an antilock braking system (ABS) controller to adjust the wheel slip to the preferred value using sliding mode control and fractional calculus. The ABS must be robust against external disturbances such as variations in the friction force between the tire and road caused by changes in the road conditions, loadings and etc. A fractional order PD switching surface is defined, then in order to improve the convergence speed and increase degree of freedom of the controller, a new sliding surface is defined as fast terminal dynamic sliding surface which is formulated using Fractional Calculus. Then, a fractional order fast terminal dynamic sliding mode controller (FOFTDSMC) is designed. Also, for estimating the upper bound value of the lumped uncertainty in the proposed controller, an adaptive FOFTDSMC is designed. The finite time stability of the closed-loop system is guaranteed. Simulation results show the effectiveness of the proposed controller in terms of fast tracking with high robustness when compared to the fractional order sliding mode controller and fractional order fast terminal sliding mode controller.

Design of Regenerative Anti-Lock Braking System Controller for 4 In-Wheel-Motor Drive Electric Vehicle with Road Surface Estimation

This paper presents a regenerative anti-lock braking system control method with road detection capability. The aim of the proposed methodology is to improve electric vehicle safety and energy economy during braking maneuvers. Vehicle body longitudinal deceleration is used to estimate a road surface. Based on the estimation results, the controller generates an appropriate braking torque to keep an optimal for various road surfaces wheel slip and to regenerate for a given motor the maximum possible amount of energy during vehicle deceleration. A fuzzy logic controller is applied to fulfill the task. The control method is tested on a four in-wheel-motor drive sport utility electric vehicle model. The model is constructed and parametrized according to the specifications provided by the vehicle manufacturer. The simulation results conducted on different road surfaces, including dry, wet and icy, are introduced.

A practical identifier design of road variations for anti-lock brake system

ABSTRACTEmergency brake technologies have always been a major interest of vehicle active safety-related studies. On homogeneous surfaces, traditional anti-lock brake system (ABS) can achieve efficient braking performance and maintain the handling capability as well. However, when road conditions are time variant during the braking process, or different at the bilateral wheels, braking stability performance is likely to be degraded. To address this problem and enhance ABS performances, a practical identifier of road variations is developed in this study. The proposed identifier adopts a statechart-based approach and is hierarchically constructed with a wheel layer and a full vehicle layer identifier. Based on the identification results, modifications are made to a four-phase wheel-behaviour-based ABS controller to enhance its performance. The feasibility and effectiveness of the proposed identifier in collaborating with the modified ABS controller are examined via simulations and further validated by track tests under various practical braking scenarios.

Electro-hydro-mechanical Braking System for Passenger Vehicle

Background and Objective: Deceleration or stopping the vehicle without a diving and lateral acceleration is essential to develop an effective braking system. The antilock braking system (ABS) and electronic stability control (ESC) has been introduced to improve the braking performance of the vehicle. However, due to the insufficient human effort, the ABS and ESC to some extent, not function well. This study develops an electro-hydro-mechanical braking system by associating the wheel speed sensor and accelerator sensor. It had been developed the additional actuation force on the brake pad to decelerate the vehicle instantaneously in the desired braking distance corresponding to the speed with less lateral acceleration. Materials and Methods: This study investigates the DC motor amplified braking system theoretically by solid work simulation model and experimentally by developing an intelligent system for controlling the DC motor based on the Markov Decision Process model. Results: The simulation model has shown that a full load passenger car needs 15.7 Mpa of braking pressure to stop 50 km/h vehicle in 10 m. The experimental results of the model show that the pressure develops when the pedal fully applied without and with aids of the DC motor is 910 kPa and 1130kPa, respectively, which contribute to increase pressure about 23.3%. Conclusion: The effectiveness of the DC motor amplified braking system would be able to break the vehicle to decelerate as soon as release the brake pedal even without the driver action which might prevent the fatal accident on the road.

Designing neuro-fuzzy controller for electromagnetic anti-lock braking system (ABS) on electric vehicle

Anti-lock braking system (ABS) is used on vehicles to keep the wheels unlocked in sudden break (inside braking) and minimalize the stop distance of the vehicle. The problem of it when sudden break is the wheels locked so the vehicle steering couldn’t be controlled. The designed ABS system will be applied on ABS simulator using the electromagnetic braking. In normal condition or in condition without braking, longitudinal velocity of the vehicle will be equal with the velocity of wheel rotation, so the slip ratio will be 0 (0%) and if the velocity of wheel rotation is 0 (in locked condition) then the wheels will be slip 1 (100%). ABS system will keep the value of slip ratio so it will be 0.2 (20%). In this final assignment, the method that is used is Neuro-Fuzzy method to control the slip value on the wheels. The input is the expectable slip and the output is slip from plant. The learning algorithm which is used is Backpropagation that will work by feedforward to get actual output and work by feedback to get error value with target output. The network that was made based on fuzzy mechanism which are fuzzification, inference and defuzzification, Neuro-fuzzy controller can reduce overshoot plant respond to 43.2% compared to plant respond without controller by open loop.

Antilock braking control system for electric vehicles

In recent years, brushless DC motors (BLDCMs) have replaced brushed DC motors in the design of electric scooters (ESs). This study proposes a new antilock braking system (ABS) based on a slip ratio estimator for ES utilising the braking force generated by the BLDCM when electrical energy is released to the virtual load, yielding an effect analogous to the ABS control in gas-powered vehicles. Compared with mechanical ABS, the proposed design possesses the advantage of rapid torque responses because no mechanical parts needed. Current control design is used to adjust the braking torque, and the sliding-mode control strategy is adopted to regulate the slip ratio to attain the optimal road adhesion during emergency braking. A variety of experiments are conducted for functional and performance verification.

Novel constrained control of active suspension system integrated with anti-lock braking system based on 14-degree of freedom vehicle model

This paper deals with a novel method for integration of the active suspension system and the anti-lock braking system. In the proposed method, a new nonlinear controller with state constraints is developed for the active suspension system based on the response prediction of 14-degree of freedom vehicle model. The proposed controller isolates the vehicle from road roughness in normal conditions and assists the anti-lock braking system by ensuring a good contact between the tyre and road during hard braking. In addition, the tyre deflection is limited to prevent the threat of tyre bursting. To develop the active suspension system controller, at first, a performance index consisting of a weighted combination of predicted responses of suspension system is expanded as a function of current control input. At the same time, the state constraints of tyre normal force and tyre deflection are transformed to the equivalent constraints of control input by the same prediction approach. Then, the control law is found by minimizing the expanded performance index in the presence of input constraints. The Karush–Kuhn–Tucker theorem is employed to solve the performed constrained optimization problem analytically. The performance of the proposed active suspension system controller integrated with the designed nonlinear anti-lock braking system controller is evaluated for a full vehicle model including roll and pitch motions during braking on irregular random roads. The results show that both the body acceleration and the vehicle stopping distance are decreased for the proposed integrated strategy compared with other conventional strategies.

Fuzzy fractional PID gain controller for antilock braking system using an electronic wedge brake mechanism

Fuzzy fractional PID gain controller for antilock braking system using an electronic wedge brake mechanism

Fuzzy fractional PID gain controller for antilock braking system using an electronic wedge brake mechanism

This paper focuses on the design of a fuzzy fractional Proportional-Integral-Derivative (PID) controller. The controller which is based on the conventional PID controller is modified to be P1–α I1–β D1–γ with the objective to make the controller more flexible and robust to the changes in input and the parameters. In this control structure, the fuzzy logic control acts as the tuner for the parameters α, β and γ, so that the overall controller parameter can be varied and converge better to the changes in a system. The designed fuzzy fractional PID controller is applied to a validated antilock braking system model using an electronic wedge brake system as the actuator. Numerous numerical simulations and comparisons with other fractional PID/conventional PID controllers show that the fuzzy fractional PID controller can not only ensure good control performance with respect to reference input but also improve the system robustness with respect to model uncertainties.

Simulation and experimental investigation of vehicle braking system employing a fixed caliper based electronic wedge brake

This paper presents an investigation into the performance of a fixed caliper based electronic wedge brake (FIXEWB) in a vehicle braking system. Two techniques were used as assessment methods, which are simulation via MATLAB Simulink software and experimental study through hardware-in-the-loop-simulation (HILS). In the simulation study, the vehicle braking system was simulated by using a validated quarter vehicle traction model with a validated FIXEWB model as the brake actuator. A proportional–integral–derivative controller was utilized as the brake torque control, whereas proportional–integral and proportional controllers were used as the position and speed control of the actuator, respectively. To study the effectiveness of the FIXEWB, the response of the vehicle using the FIXEWB is compared with the responses of a vehicle using a conventional hydraulic brake. A dynamic test, namely braking in the sudden braking at constant speeds of 40 and 60 km/h was then used as the testing method. The simulation results show that the usage of the FIXEWB with an appropriate control strategy produces similar behavior to that of a hydraulic brake in terms of the produced desired braking torque but with faster time response. To study the performance of the FIXEWB when implemented on a real vehicle, an experimental rig using HILS was designed and the results are analyzed using the same dynamic tests. The performance areas evaluated are vehicle body speed, wheel speed, tire longitudinal slip, and the stopping distance experienced by the vehicle. The outcomes from this study can be considered in the design optimization of an antilock braking system control in a real car in the future.

Data-driven model-free slip control of anti-lock braking systems using reinforcement Q-learning

Abstract This paper proposes the design and implementation of a model-free tire slip control for a fast and highly nonlinear Anti-lock Braking System (ABS). A reinforcement Q-learning optimal control approach is inserted in a batch neural fitted scheme using two neural networks to approximate the value function and the controller, respectively. The transition samples required for learning high performance control can be collected by interacting with the process either by online exploiting the current iteration controller (or policy) under an e-greedy exploration strategy, or by using data collected under any other controller that is capable of ensuring efficient exploration of the action-state space. Both approaches are highlighted in the paper. Fortunately, the ABS process fits this type of learning-by-interaction because it does not need an initial stabilizing controller. The validation case studies conducted on a real laboratory setup reveal that high control system performance can be achieved using the proposed approaches. Insightful comments on the observed control behavior are offered along with performance comparisons with several types of model-based and model-free controllers including relay, model-based optimal PI, an original model-free neural network state-feedback VRFT controller and a model-free neural network adaptive actor-critic one. With the ability to improve control performance starting from different supervisory controllers or to learn high performance controllers from scratch, the proposed Q-learning optimal control approach proves its performance in a wide operating range and is therefore recommended to its industrial application on ABS.

The Next Level - Controlled Conformal Coating Processes

Talking about purified assembled printed circuit boards (PCBs), e.g. in automotive industry for control of airbag or anti-lock braking systems (ABS), one of the main issues is the protection against environmental impact. The error-free functionality must be guaranteed even at the North Cape, the Rainforest or in the desert and this warranty has to be provided for even a decade.

Passenger car active braking system: Model and experimental validation (Part I)

This paper introduces a method to characterize the dynamic behavior of a normal production hydraulic brake system through experiments on a hardware-in-the-loop test bench for both modeling (part I) and control (part II) tasks. The activity is relative to the analysis, modeling, and control of anti-lock braking system and electronic stability control digital valves, and is aimed at obtaining reference tracking and disturbance-rejection performance similar to that achievable when using pressure proportional valves. The first part of this two-part study is focused on the development of a mathematical model that emulates the pressure dynamics inside a brake caliper when the inlet valve, outlet valve, and motor pump are controlled by digital or pulse width modulated signals. The model takes into account some inherent nonlinearities of these systems, e.g. the variation of fluid bulk modulus with pressure, while inlet and outlet valves together with the relay box are modeled as second-order systems with variable gains. The hardware-in-the-loop test rig is used for both parameter estimation and model validation; the parameters and model will be used for the control strategy development presented in the second part of this study.

Research on HILS Technology Applied on Aircraft Electric Braking System

On the basis of analyzing the real-time feature of hardware-in-the-loop simulation of aircraft braking system, a new simulation method based on MATLAB/RTW (Real-Time Workshop) and DSP is introduced. The purpose of this research is to develop a digital control unit with antilock brake system control algorithm for aircraft braking system using HILS. DSP is used as simulator. Using this method, a detailed mathematical modeling of system is proposed first. Studies on reducing sampling time with model simplification and modeling for applying to I/O interface of DSP and HILS are conducted. Compared with other methods, this method is low cost and convenient to implement. By using these methods, we can complete HIL simulation of aircraft braking under various experimental conditions, modify its control laws, and test its braking performance. The results have demonstrated that this platform has high reliability. The algorithm is verified by real-time closed loop test with HILS system and the results are presented.

PID-Sliding Surface Based Sliding Mode Controller for Anti-Lock Braking System of Electric Vehicle

Anti-lock Braking System (ABS) is a crucial part in electric vehicle. It is an uncertain and nonlinear system. In this paper a Sliding Mode Control (SMC) technique with PID sliding surface is used to maintain the slip ratio, at 0.2 of ABS system. The mathematical representation of a quarter vehicle model that emphasizes essential characteristics of the whole vehicle was implemented in this research. The model was developed using Simulink and the proposed SMC technique was tested and validated. In addition, the sliding mode enforcement was ensured via stability analysis. The simulation results have shown good agreement and acceptable response of the ABS system

Cooperative control of regenerative braking and friction braking in the transient process of anti-lock braking activation in electric vehicles

Regenerative braking significantly improves the energy efficiency in electric vehicles. Cooperative control between regenerative braking and friction braking during anti-lock braking control is a critical issue in brake system coupling. For safety concerns, regenerative braking is often terminated at the beginning of anti-lock braking control. Oscillations between activation of an anti-lock braking system and exit from anti-lock braking system control may occur under poorly matched control parameters. To solve these problems, we propose an index that indicates the possibility of activation of an anti-lock braking system. It is derived by a fuzzy logic algorithm which is based on the estimated regenerative braking torque, the estimated friction braking torque and other vehicle state variables. Regenerative braking can be adjusted on the basis of the index to ensure that such braking is of a low level when an anti-lock braking system is activated. Simulations and experiments are carried out to evaluate the effectiveness of the index. The results show that regenerative braking decreases as the index increases, thereby improving the braking safety and the driving comfort during the transient process of activation of an anti-lock braking system.

Existence and stability of limit cycles in control of anti-lock braking systems with two boundaries via perturbation theory

ABSTRACTThis paper presents a two-phase control logic for anti-lock braking systems (ABS). ABS are by now a standard component in every modern car, preventing the wheels from going into a lock situation where the wheels are fixed by the brake and the stopping distances are greatly prolonged. There are different approaches to such control logics. An ABS design proposed in recent literature controls the wheel's slip by creating stable limit cycles in the corresponding phase space. This design is modified via an analytical approach that is derived from perturbation theory. Simulation results document shorter braking distance compared to available tests in the literature.

Fuzzy based Adaptive Control of Antilock Braking System

Fuzzy based Adaptive Control of Antilock Braking System

Design and Analysis of Controller for Antilock Braking System in Matlab/Simulation

Design and Analysis of Controller for Antilock Braking System in Matlab/Simulation