Research and Verification of the Logic Threshold Self-adjusting Control Method for ABS

Braking system plays a major safety feature in any vehicle; it is considered as one of the key points in safe motoring. The main objective of a good braking system is to provide safe stopping, in addition to the fact that it provides repeatable stopping. Anti-lock Braking System (ABS) is one of the recently developed safety feature used in a vehicle in order to prevent wheels from locking. This article proposes an intelligent adaptive fuzzy logic (FL) genetic algorithm (GA) controller for the Anti-Lock Braking System (ABS) to control the braking of a vehicle by controlling the slip ratio based on quarter car model. The main objective of the proposed controller is to prevent wheels from locking, which is a major safety issue in any braking system for different road conditions. The proposed controller consists of a Fuzzy Logic (FL) Genetic Algorithm (GA) based controller. The Genetic Algorithm is utilized in tuning the membership functions of the Fuzzy logic controller, which is developed to calculate the amount of reduction of the applied torque due to applying brake based on the error of the measured slip ratio signal compared with the desired one. Then a Genetic Algorithm (GA) is utilized in tuning the Fuzzy Logic parameters, which are the center of the Gaussian membership function, and the spread (б). The simulation results of the proposed fuzzy logic genetic algorithm controller are compared with both the results of the Fuzzy logic controller and the PD controller developed in previous work of the authors. The simulation results present many advantages of using Fuzzy Logic Genetic Algorithm based controller over both the Fuzzy Logic and the PD controllers, and the simulation is carried out at different road conditions, namely dry, wet and icy road surface.

The study investigates the braking characteristics of heavy-load five-axle special vehicle to improve the braking safety of it. The mechanical system with strong coupling is studied by means of multi-body dynamics analysis method, and the refined vehicle dynamics model including braking system, suspension system, steering system, and other components is established via platform of Adams/Car. Through road test experiments, the accuracy and reliability of the model under conditions of 80 m constant turning radius circle and emergency braking of 60 km/h initial speed are verified. The classical ABS (Anti-lock Braking System) control strategy with logic threshold including a road recognition module and a slip ratio calculation module is established in Simulink, which matches the ABS control system of 6 S/6 M for the five-axle special vehicle well. By changing adhesion conditions of a single road and the control channel modes of the split-mu road, the control effect of the ABS control system on the braking performance of the five-axle vehicle is determined by the co-simulation. The experimental and simulation results indicate the following: (1) The vehicle dynamics model can effectively simulate the structure of the actual vehicle mechanical system and mechanical constraints, and has good braking performance and steering performance; (2) ABS external control system and heavy-load five-axle vehicle model can be matched, and during the control process, logic thresholds need to be repeatedly adjusted to adapt to different types of roads. (3) The change of road adhesion coefficient will affect the control effect of ABS. The baking performance can be improved more in low adhesion road than in high adhesion road. (4) Split-mu road is more special and has a great impact on the lateral stability of braking. It can be seen through comparative analysis of high-selection and low-selection control that braking safety is better under low selection control mode.

Hierarchical [formula omitted] fuzzy-neural control of anti-lock braking system and active suspension in a vehicle

The objective of this paper is to propose a modified optimal sliding mode control method for the hydraulic anti-lock braking system of a vehicle to achieve both robustness and optimal control performance. The longitudinal dynamic model of a vehicle, tyre model and hydraulic anti-lock braking system model are established, and the weakness of the common optimal sliding mode control method in designing the anti-lock braking system controller is analysed synthetically. The analyses form the basis for tracking an ideal slip ratio. A new modified optimal sliding mode controller is proposed to regulate the hydraulic anti-lock braking system for a better braking performance and robustness: the optimal sliding mode manifold function includes several virtual damping elements and infinitely small-sized items to meet the working conditions of the current optimal sliding mode control method. The control results of the proposed controller are compared with those of the common sliding mode controller. Simulation results under various road conditions demonstrate that the modified optimal sliding mode controller not only has strong robustness against uncertainties in the road adhesion coefficient but also achieves better control performance of the slip ratio.

Electric vehicles (EVs) have the advantage of using both regenerative braking and mechanical braking to produce the necessary braking torque. Currently, vehicles use Anti-lock Braking Systems (ABS) which provide intermittent braking torque to the vehicle and thereby prevents skidding or slipping of the vehicle by ensuring pure rolling of the wheels. Regenerative braking on the other hand generates the necessary braking torque by converting the kinetic energy of the vehicle to electrical energy via the motor(s). To coordinate both braking systems, the conventional method involves the use of crisp logic controllers that depend on lookup tables containing the data about various aspects of the vehicle such as battery state of charge (SoC), brake pedal input etc., to enable co-operative control of both systems. This paper presents a combined implementation of both braking systems in electric vehicles using separate fuzzy controllers for both ABS and regenerative braking. The control scheme is implemented such that when regenerative braking is not capable of providing enough braking torque, braking will be one by ABS. Two fuzzy logic controllers have been used, one to implement regenerative braking and the other to implement mechanical braking via ABS. If such a control algorithm is used, the driver will not have to manually adjust the level of regenerative braking in the vehicle and such an approach ensures that the braking process of an EV is smooth, safe and efficient. It also reduces the wear and tear of the brake pads thereby extending their life and reducing the cost of maintenance and by extension the total cost of ownership of the vehicle. The results demonstrate that the controllers for both ABS and regenerative braking can coordinate efficiently and reliably to produce proper and safe braking of the vehicle.

This study aims to analyze the effect of load variation on braking efficiency and disc temperature in Yamaha Aerox automatic motorcycles equipped with an Anti-lock Braking System (ABS) using the roadtest method. The experimental research method was applied, with independent variables including load variations (65 kg, 85 kg, 130 kg, and 150 kg) and two ABS conditions (active and inactive). The dependent variables observed were braking distance, deceleration, braking efficiency, and disc temperature. The research findings indicate that at low speeds (40 km/h), the ABS system results in a longer braking distance compared to non-ABS conditions. However, at high speeds (50 km/h), ABS proves to be more effective in optimizing braking performance and preventing wheel lock, especially under heavier loads. The lowest average value in braking efficiency is obtained in the ABS ON 40 km/h treatment with a load of 150 kg, the result is 51%. while the highest average value of efficiency is obtained in the ABS ON 50 km/h treatment with a load of 65 kg, the result is 92%. Additionally, load variation significantly affects the increase in disc temperature, with heavier loads leading to higher disc temperatures after braking. The lowest average for disc temperature was obtained in the ABS ON 40 km/h treatment with a load of 65 kg, the value is 37.16 degrees Celsius. while the highest average value of disc temperature was obtained in the ABS OFF 50 km/h treatment with a load of 150 kg with an average value of 73.1 degrees Celsius. This study provides valuable insights into the effectiveness of ABS in enhancing road safety and highlights the importance of regulatory considerations regarding the implementation of ABS in motorcycles in Indonesia.

<div>As the basic function of the active safety configuration of a vehicle, the anti-lock braking system will compromise the driving safety if it fails. Based on the self-designed electro-hydraulic braking system, this article proposes an anti-lock brake redundant control architecture. The electro-hydraulic braking system is mainly composed of four parts: a brake pedal unit, a hydraulic drive unit, a brake execution unit, and a control unit. The mechanical structure is compact and exquisite, and the system has the function of precise and adjustable hydraulic pressure. The control architecture adopts a hierarchical control design, which is mainly composed of an upper wheel slip rate controller and a lower hydraulic pressure controller. Both the upper and lower controllers use a sliding mode variable structure control to improve the robustness and accuracy of the control. The upper slip rate controller outputs the desired master cylinder hydraulic pressure with the optimum slip rate of the rear wheels of the vehicle as the control target. The lower hydraulic pressure controller outputs the desired torque of the motor with the desired master cylinder hydraulic pressure as the target and achieves hydraulic pressure regulation of the master cylinder by controlling the motor motion. To verify the effectiveness of the algorithm, co-simulation and a hardware-in-the-loop test platform are built. Anti-lock braking tests are carried out under different typical working conditions: low-adhesion road, high-adhesion road, butt road, and split road. The results show that when the anti-lock braking system fails, the redundant control algorithm can achieve effective slip rate control under different driving road conditions and meets the anti-lock brake redundant control requirements. This study provides a reference for the development of low-cost anti-lock braking redundancy functions for vehicles equipped with electro-hydraulic braking systems.</div>

This paper presents the development of a PID controller for an Antilock Braking System (ABS) using vehicle longitudinal model. A Five Degree of Freedom (5-DOF) vehicle longitudinal dynamic model was derived and integrated with an analytical tyre dynamics, the Magic Tyre model. Several transient handling tests are performed such as sudden acceleration and sudden braking test to validate the vehicle model. The model is used as a plant to develop an antilock braking system to control longitudinal slip and reduce the stopping distance. A hydraulic brake model was developed as the brake actuator to produce brake torque. A conventional PID controller has been implemented to deal with the strong nonlinearity in the design of ABS controller. The proposed ABS control structure is shown able to significantly reduce stopping distance and control the longitudinal slip during heavy braking.

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

The paper considers the Anti-lock Braking System (ABS) operation algorithm, which enables the implementation of hybrid braking, i.e. the braking process combining friction brake mechanisms and e-machine (electric machine), which operates in the energy recovery mode. The provided materials focus only on the rectilinear motion of the vehicle. That the ABS task consists in the maintenance of the target wheel slip ratio, which depends on the tyre-road adhesion coefficient. The tyre-road adhesion coefficient was defined based on the vehicle deceleration. In the course of calculated studies, the following operation algorithm of hybrid braking was determined. At adhesion coefficient ≤0.1, driving axle braking occurs only due to the e-machine operating in the energy recovery mode. In other cases, depending on adhesion coefficient, the e-machine provides the brake torque, which changes from 35 to 100% of the maximum available brake torque. Virtual tests showed that values of the wheel slip ratio are close to the required ones. Thus, this algorithm makes it possible to implement hybrid braking by means of the two sources creating the brake torque.

To research the influence of the proportional relay valve on the economy and safety of the electric bus through the braking recovery system, a proportional relay valve model was proposed. Based on the analysis of the structure and working principle of the solenoid on/off valve, a dynamic model of “electro-magnetic-machine-air” coupling was simulated and analyzed. Then, based on the solenoid on/off valve and proportional relay valve, two pressure regulator modules were designed, the braking energy recovery system schemes were designed, respectively. Fuel economy tests were carried out under China city bus typical driving cycle based on two kinds of air pressure regulating module to research the influence of the proportional relay valve on the economy of the electric bus. An integrated control system of braking energy recovery and anti-lock braking system based on the proportional relay valve was proposed, hardware-in-the-loop braking energy recovery system contrast tests of the anti-lock braking system were also carried out based on two kinds of air pressure regulating module. The test results indicated that the proposed braking energy recovery system schemes were effective. The test results also demonstrated the economic contribution rate of the braking energy recovery of the proportional relay valve pneumatic control module was slightly higher than that of the proportional relay valve. Meanwhile, the proportion relay valve pressure regulating module achieved a good target speed follow and the accurate adjustment of air pressure in anti-lock braking system control.

<div class="section abstract"><div class="htmlview paragraph">An accurate estimate of vehicle speed is essential for optimal anti-lock braking system (ABS) calculations. Currently, most vehicles including heavy-duty class 8 trucks mainly rely on wheel speed sensors (WSS) to estimate velocity. However, as soon as braking is applied, WSS become inaccurate for determining the velocity due to the longitudinal slip developed in the tires. Using the inertial measurement unit (IMU) to estimate vehicle speed allows for its use in conjunction with the WSS to accurately calculate the slip ratio at each tire. These slip ratio values can then be used as the main control variable in the ABS algorithm to utilize the grip available more fully at each tire, to improve stopping distance and controllability. A steady state braking analysis model is developed and validated against Federal Motor Vehicle Safety Standards (FMVSS) 121 60-0 mph stopping distance data for a loaded class 8 tractor semi-trailer combination. Once the model is validated to show good correlation to measured deceleration data, it is used to estimate the theoretical peak steady state deceleration with the ideal slip ratio at each tire. Then a semi-empirical approach is used to consider current air brake system and ABS algorithm capabilities in the analysis. Lastly, the initial transient phase of 60-0 mph stop is accounted for to get a realistic stopping distance improvement estimate for a loaded heavy-duty truck.</div></div>

With the development of the global automotive industry, environmental pollution and driving safety have been major problems. This paper focuses on a novel integrated cooperative antilock braking system (ABS) controller, which is used for antilock regenerative braking systems (ARBS) and antilock mechanical braking systems (AMBS) for hybrid electric vehicles (HEV) driving on different road surfaces. An intelligent tire system is utilized to detect varying road surfaces to obtain friction information and optimal operation slip ratio. In addition, the HEV eight‐degree‐of‐freedom dynamics model is developed for ABS control, which includes the LuGre tire model. Adaptive backstepping and finite state machine controllers are explored to maintain optimal wheel slip and regenerate energy, based on wheel slip, battery state of charge (SOC), motor capability torque, and vehicle velocity, and to develop the switching rules of regenerative and mechanical braking systems. In order to evaluate the performance of regenerative and mechanical braking systems on harvesting energy and driving safety, the HEV and LuGre dynamic tire models are developed in MATLAB SIMULINK /SimDriveline. The estimation results of different road surfaces and slip controller effects are tested via the experiments and simulations, finding good braking performances and high regenerative efficiency in different maneuvers.

ABS (Anti-lock Braking System) can avoid the wheel locking when the vehicle urgently brakes as an auxiliary braking system. Its performance parameter must be accord with some evaluation standard. The vehicle equipped with ABS was studied in this paper. The main performance examination parameter was determined and mathematical model of ABS was established. The module and the test stand of ABS performance examination experiment were designed by LabVIEW. Then experiment was carried on the test stand. ABS performance examination parameter was collected, analyzed and handled. In the end, the method of performance examination was tested. The result shows that the virtual experiment can get the same result as the vehicle road test and it has greater efficiency.

In order to solve the problem of modelling, simulation and optimisation of magnetorheological brake (MR brake) which is a multi-domain coupling system, the braking performance and control parameters optimisation of MR brake were investigated under a quarter-car model. Firstly, based on Modelica/MWorks platform, using multi-domain unified modelling method, a multi-domain unified MR brake model with anti-lock braking system (ABS) was built. Then by using response surface method (RSM), the response surface function to express the relation between braking distance and three control parameters was formulated, and the optimisation problem of control parameters was solved at MWorks. Finally, according to the optimal control parameters and the structure parameters of MR brake designed by our group before, the simulation of the multi-domain unified MR brake model was done to analyse the change regularity of vehicle speed, slip ratio, braking distance, control current, braking time, etc. under the effect of controller. Results show that MR brake with optimal control parameters has a good braking performance and can meet the requirements of GB7258-2012 standard. This lays the foundation of application of MR brake in vehicles.