Braking Control Research Articles

Experimental Confirmation of a Controllable Transmission/Braking Element Consisting of a Functional Elastomer Pasted on a Winding Surface

Electoadhesive (EA) gel can be applied to various mechatronics devices because it provides more degrees of freedom in mechanical design than other functional materials. While case studies have revealed much about these devices, the knowledge attained is still not integrated. We assembled new structured and controllable transmission and braking elements by fixing EA gel on plain and/or winding surfaces. This paper summarizes the characteristics of these devices from experimental findings on the initial pressure on the EA gel surface. The results showed that it is important for the initial pressure to be stable at approximately 0.5–1 kPa.

Adaptive constrained antilock braking control under unknown time-varying slip-friction characteristics

Adaptive constrained antilock braking control under unknown time-varying slip-friction characteristics

A multi-objective regenerative braking control strategy combining with velocity optimization for connected vehicles

Deceleration is unavoidable owing to the traffic lights or obstacles during driving, which lead to great energy dissipation. To promote energy utilizing efficiency, regenerative braking is applied to convert kinetic energy into electricity. Previous researches about regenerative braking concentrate on the braking torque allocation optimization, which is undoubtedly important. Moreover, the control performance can be further improved combining with velocity optimization. With the emerging Connected Vehicle Technology, environmental information is available for vehicles. Therefore, the terminal braking distance and terminal velocity can be derived utilizing the information. Then a multi-objective regenerative braking control strategy based on the pesudospectral method is proposed with the terminal constraints. The control strategy optimizes both the velocity and braking torque allocation to reduce the energy dissipation and battery capacity loss simultaneously. Simulations are carried out under a speed bump scenario. Pareto front is obtained with different weights of the objectives and then analyzed to reveal the tradeoff between energy recovery and battery health, which assists in finding a desired balanced solution. Two representative Pareto optimal solutions are selected for comparison: the energy recovery priory strategy and the energy-life tradeoff strategy. Compared with the energy priory strategy, the energy-life tradeoff strategy decreases the battery capacity loss by 60.65%, but it leads to a 36.07% reduction in the energy recovery.

Environment-on-Board Predictive Braking Control Functions for Autonomous Driving During Sudden Changes in the Road Friction Coefficient on Sharp Curves

Environment-on-Board Predictive Braking Control Functions for Autonomous Driving During Sudden Changes in the Road Friction Coefficient on Sharp Curves

Analysis of Slip rate Control Technology of Electric Vehicle Based on Sliding Mode Algorithm

With the increasingly prominent environmental and energy problems, it is very important to strengthen the research of new energy vehicles. In the research process of new energy vehicles, the safety of electric vehicles during driving is extremely important. In the braking process of electric vehicles, wheel slip control is an important factor to ensure the safety of electric vehicles. In the process of slip rate control, it is necessary to identify the wheel slip rate under different road surfaces, so as to complete the design of the slip rate controller on the basis of mastering the wheel friction characteristics. In this research, we mainly consider the maximum braking torque limit of motor output, scientifically distribute regenerative braking and hydraulic braking torque, complete the design of slip rate controller based on sliding mode algorithm, and introduce saturation function to solve the buffeting problem in road friction adaptive slip rate control method. Put forward the core of slip rate control strategy of electric vehicle. Through research, it is determined that the reasonable division of regenerative braking and mechanical braking based on slip rate can improve the safety of vehicle braking and ensure the efficiency of energy recovery. Therefore, in the process of electric vehicle slip rate control, the regenerative braking control method based on slip rate closed-loop control has application value.

Research on Vehicle Rollover Warning and Braking Control System Based on Secondary Predictive Zero-Moment Point Position

<div class="section abstract"><div class="htmlview paragraph">To solve the contradiction between model complexity and the warning accuracy of the algorithm of the vehicle rollover warning, a rollover state warning method based on the secondary predictive zero-moment point position for vehicles is proposed herein. Taking a sport utility vehicle(SUV) as the research object, a linear three-degrees-of-freedom vehicle rollover dynamics model is established. On the basis of the model, the lateral position of the zero-moment point and its primary and secondary rates of change are calculated. Then, the theoretical solution of time-to-rollover of the vehicles is deduced from the lateral position of the secondary predictive zero-moment point. When the rollover warning index, the lateral position of the zero-moment point, is greater than the set threshold, the active anti-rollover control system will be triggered. The active anti-rollover braking control system adopts a hierarchical control strategy. Taking the rollover warning index as the control target, the upper controller calculates the braking torque required by the front-outer wheel based on the Fuzzy Proportional Integral Derivative (PID) algorithm and the differential braking control strategy. The lower executive controller calculates the corresponding brake wheel cylinder pressure and inputs it to the corresponding wheel through the Electrical Hydraulic Brake(EHB), so that a certain additional yaw moment can be formed to prevent the vehicle from rolling over. Under some typical driving conditions, Carsim-Matlab co-simulation and real vehicle tests are carried out. The comparative test results show that the proposed rollover warning method based on the secondary predictive zero-moment point position can accurately and effectively predict the roll-over state of the vehicle, and the active anti-rollover braking control system can control the vehicle in time and effectively to prevent the vehicle from rollover.</div></div>

Integrated simulation platform for a locomotive braking system

We used a locomotive and a rail car to examine the working principle of a locomotive braking system. We established models of the locomotive braking system, the locomotive dynamics, and the brake disc thermodynamics and, based on the correlation parameters for each subsystem, built an integrated simulation platform for the locomotive braking system based on Simulink and AMESim. Using this platform, we simulated the characteristics of the pneumatic braking unit, the locomotive braking, and temperature increase in the brake disc under emergency braking conditions. We compared our simulation results with experimental data and the results showed that the integrated simulation platform for the locomotive braking system could successfully be used to study locomotive braking control on the vehicle level. We provide a design optimization method for the development of a braking system, the setting of the anti-skid criterion, and early warning of an increase in the brake disc temperature.

A Novel Anti-Saturation Model-Free Adaptive Control Algorithm and Its Application in the Electric Vehicle Braking Energy Recovery System

In this work, a novel anti-saturation model-free adaptive control (AS-MFAC) algorithm is proposed for the problem of pure electric vehicle’s braking energy recovery with the uncertain dynamic external factors. In the process of energy recovery during vehicle braking, actuator saturation and error accumulation occur due to various external conditions. In AS-MFAC, the non-linear dynamics of the vehicle braking energy recovery process is firstly linearized via a novel dynamical linearization technique with a time-varying parameter pseudo partial derivative (PPD). Then, by proposing the concept of the saturation parameter, the AS-MFAC controller is designed. Consequently, the stability and safety of the braking system are guaranteed while ensuring energy recovery. The major advantages of the AS-MFAC algorithm are that the controller uses only input and output data from the regenerative braking control system and this approach addresses the actuator saturation problem as well as provides a feasible solution. Moreover, the stability of the AS-MFAC algorithm is proven by rigorous mathematical theory and its effectiveness is verified by a series of experimental simulations. Remarkably, the proposed AS-MFAC controller has the property of symmetry since the controller structure and the corresponding parameter (time-varying PPD) estimator are both inferred based on the project algorithm. Consequently, the structures of the controller and the parameters of AS-MFAC have a symmetric similarity.

Stability/instability of magnetorheological core sector structure for mechanical control braking system by the intelligent computer method

ABSTRACT Due to the amazing mechanical properties of the magnetorheological (MR) materials, which can quickly transit from fluid to solid and vice versa, these materials have attracted a lot of attention among designers. So, for the first time, a dynamic stability analysis of a sandwich sector plate made of an MR core and two graphene nanoplatelets reinforced composite (GPLRC) face sheets has been presented. Using the role of mixture and Halpin–Tsai model, material properties of the GPLRC layers have been modeled. For modeling the MR core, shear stress and strain properties of MR fluids have been characterized into pre-yield and post-yield regions. Via first-order shear deformation theory, compatibility equations between the layers, and Hamilton’s principle, motion equations of the structure have been achieved. A generalized differential quadrature method with Chebyshev polynomials greed points has been applied for obtaining the responses of structure. The verification section has been separated into two parts. The first and second ones are verification between the current outcomes with the results of the published report and the machine learning method based on deep neural networks, respectively. Consequently, the results show that some geometrical and physical parameters have an important role in the dynamic stability of the current structure.

Principle design and control of a brake-by-wire actuator featuring magnetorheological clutch

Electro-mechanical brake (EMB), driven by a motor to push the brake pads to clamp the brake disk for braking, is considered as the future of vehicle braking system, because of its simple structure and controllable braking force. However, EMB must face the problem of motor blocking when it works in a long-time continuous braking condition. When the motor is blocking, the current in the coil windings is large enough to burn the motor down, leading to the failure of EMB, which is a great threat to driving safety. To solve the problem, a new brake-by-wire actuator featuring magnetorheological (MR) clutch (MRC) – an EMB combining with an MRC, i.e., BBW-MRC, is presented in this paper. Specifically, the BBW-MRC is composed of a driving motor, an MRC, a planetary gear reducer, a ball screw, brake pads, and a brake disk. The motor output is transmitted to the MRC through the reducer, and it is controlled in real-time, continuously, and as expected by the MRC via controlling its applied current. The ball screw is driven by the MRC and pushes the brake pads to clamp the brake disk to realize braking in time. The small-scaled BBW-MRC system and the corresponding test bench are developed, and a hierarchical control strategy applied to the BBW-MRC system is designed. Based on the test bench, a series of tests are carried out on the BBW-MRC system, including the stability test of the BBW-MRC system under a long-time braking condition, the braking force response test of the BBW-MRC, and the braking force tracking test. Research results show that: (1) the BBW-MRC system has a quick and accurate performance to track desired braking forces; (2) under long-time braking conditions, the braking force keeps stable and the surface temperature of the motor has a normal change; and (3) the braking force response time has a 53.5% improvement over the EMB that driven by the motor directly.

Integrated control of braking and steering systems to improve vehicle stability based on optimal wheel slip ratio estimation

Integrated control of braking and steering systems to improve vehicle stability based on optimal wheel slip ratio estimation

Design and Verification of an Electro Hydrostatic Brake System

Electro-Hydraulic Actuation is a distributed power telex technology which integrates machine, electricity and liquid as one. A miniaturized Electro-Hydraulic Brake System is designed by introducing Electro-Hydraulic Actuation Technology into aircraft Anti-skid Brake System. It can transmit power by electricity in brake system. Firstly, the mathematical model of the Electro-Hydraulic Braking System is established. Secondly, the semi physical simulation of the hardware in the loop is completed in the real-time simulation platform to verify the anti-skid braking control function of the system, realize the parameter optimization process, and determine the important parameters, so as to provide guidance for the production of the sample. Finally, the correctness and function of the Electro-Hydraulic Brake System are verified by the test on the inertial platform. The results show that the system can achieve the expected anti-skid braking function, and can provide support for subsequent engineering.

Sensotronic Brake Control System

Abstract: Sensotronic Brake Control (SBC™) works electronically, and thus faster and more precisely, than a conventional hydraulic braking system. As soon as you press the brake pedal and the sensors identify the driving situation in hand, the computer makes an exact calculation of the brake force necessary and distributes it between the wheels as required. This allows SBC™ to critically reduce stopping distances. SBC™ also helps to optimise safety functions such as ESP®, ASR, ABS and BAS. Keywords: SBC, ABS. BAS, TCS, ESP

Implementation of Robotic Ankle–Foot Orthosis With an Impedance-Based Assist-as-Needed Control Strategy

Abstract In this paper, a robotic ankle–foot orthosis (AFO) is developed for individuals with a paretic ankle, and an impedance-based assist-as-needed controller is designed for the robotic AFO to provide adaptive assistance. First, a description of the robotic AFO hardware design is presented. Next, the design of the finite state machine is introduced, followed by an introduction to the modeling of the robotic AFO. Additionally, the control of the robotic AFO is presented. An impedance-based high-level controller that is composed of an ankle impedance based torque generation controller and an impedance controller is designed for the high-level control. A compensated low-level controller that is composed of a braking controller and a proportional-derivative controller with a compensation part is designed for the low-level control. Finally, a pilot study with eight healthy participants is conducted, and the experimental results demonstrate that with the proposed control algorithm, the robotic AFO has the potential for ankle rehabilitation by providing adaptive assistance. In the assisted condition with a high level of assistance, reductions of 8% and 20.1% of the root mean square of the tibialis anterior and lateral soleus activities are observed, respectively.

Simulation and Experimental Study of Nonlinear Characteristics for Multi-mode Driving of Intelligent Vehicles

To study the nonlinear characteristics simulation and experiment of multimode driving of intelligent vehicle, an improved neural network PID controller is proposed to realize the safe and active braking requirements of cruise vehicles, according to the study of vehicle dynamics of different active braking forms and the joint simulation of road condition, driving condition, and braking mechanical structure. On the basis of the current research, the four-layer neural network combined with PID control is proposed in this paper, which can better control the braking compared with the traditional PID controller and BP neural network, safety, efficiency and stability have been improved in the following cars. According to the animation simulation demonstration of CAR SIM software, it can be determined that the improved neural network PID controller in the mechanical system can realize the safety and active braking requirements of cruise vehicle, and it is more accurate and efficient than the traditional BP neural network PID controller. Relevant parameters of the existing millimeter-wave radars are set by the radar sensors, and the long-distance horizontal detection range is plus or minus 10 degrees. The radar is installed on the longitudinal axis of the front bumper and has a height of 442[Formula: see text]mm. According to Car SIM’s preset radar sensor module parameters, the sensors can independently collect and transmit relevant data, it is also possible to cooperate with other sensors for the same variable parameter to increase the accuracy and avoid abnormal errors caused by the failure of a certain sensor. Compared with the traditional PID controller and BP neural network, the combination of four-layer neural network and PID control can carry out better braking control and improve the safety, efficiency, and stability of the following cars.

About Braking of Wheeled Vehicle Equipped with Automated Brake Control System

The paper proposes a method for determining a vehicle stopping distance based on a braking rate and a coefficient of using an adhesion force by an automated control system for regulating a braking force on the example of a multi-axle vehicle. The aim of the study is to calculate parameters of the braking efficiency of a multi-axle wheeled vehicle equipped with an automated braking force control system based on the adhesion between a tire and a supporting surface. A peculiarity of the considered method is the use of the calculated braking coefficient of the vehicle and the coefficient of use of adhesion forces during the operation of automated system for regulating the braking force. The presence of new mathematical relationships between the position of the coordinate of the vehicle’s gravity center, realized by the clutches of its wheels, and the braking coefficient of the vehicle makes it possible to simulate the change in the deceleration of a wheeled vehicle in various braking modes of its motion. The terms describing the interaction of an elastic tire with a supporting surface in the braking mode of a wheeled vehicle have been substantiated. Equations are written that permit to calculate: a position of the coordinate of gravity center of a multi-axle wheeled vehicle relative to its front and rear axles; a braking coefficient value of a multi-axle wheeled vehicle based on the coordinates of the position of its gravity center, clutches that are realized between its tires and a supporting surface; load distribution between the respective front and rear axles of the vehicle. To calculate the stopping distance of a wheeled vehicle, it is proposed to take a coefficient value of use of the adhesion force equal to 0.83, regardless of the change in weather and climatic conditions in which the vehicle is operated (a calculation error under an accepted assumption is not more than 5 %). In a graphical form, a design diagram of the coordinate position of a gravity center of a multi-axle wheeled vehicle is presented, which gives a general idea about the redistribution of masses between front and rear axles of the vehicle. Scientific publications on the change in the value of the realized adhesion between the tire and the supporting surface in the braking mode of the automobile wheel under various factors have been analyzed in the paper. The proposed concept for determining parameters of the braking efficiency of a multi-axle wheeled vehicle clarifies some provisions in the theory of vehicle motion, in particular, it allows to apply the calculated method for determining the deceleration of a vehicle in the problem of increasing vertical loads on the axles of a multi-axle wheeled vehicle in the braking mode. The given method for calculating coefficients of weight distribution between adjacent front or rear axles of a multi-axle wheeled vehicle increases an accuracy of determining the amount of deceleration of the vehicle by the calculation method.

Integrated Path Tracking Control of Steering and Differential Braking Based on Tire Force Distribution

Integrated Path Tracking Control of Steering and Differential Braking Based on Tire Force Distribution

Centrifugal controller of rotation frequency for vertical axis wind turbines

The market for small vertical axis wind turbines (VAWTs) continues to grow rapidly, filling up especially the low wind potential locations. Since the Saudi Government has announced to install 9 GW of wind power by 2032, this ambitious plan could be at least partially improved by the small wind turbines, taking into account the low annual mean wind speed on the most Kingdom of Saudi Arabia territory.However, the safety and durability of most commercially available VAWTs have not been adequately addressed with respect to the turbine over speed in high wind speed conditions.The presented research gives a methodology for calculating a cost-effective dynamic braking controller, based on a centrifugal mechanical activation spring-load mechanism with a pendulum. The analysis is focused on a small two-tier 3 kW Darrieus VAWT, where a mechanically activated friction brake is deployed as the turbine rotational speed approaches a red line. The proposed method makes a small turbine absolutely safe on any available wind speed and/or during accidental electric load switch off. The analysis was made for a typically high continental wind speed of 25 m/s.The paper presents the calculation model in VisSim software. Controller parameters were developed as the result of the research conducted on a functional turbine of the specific size in the model. The experiments covered two different cases: with a relatively low spring stiffness coefficient (400 N/m), showing the periodical oscillations of a controller pendulum on the cut-out speed and a high spring stiffness coefficient (4000 N/m), which the VAWT rotor can be surely braked at.The paper is intended to provide the mathematical basis for the scientific analysis, as well as providing practical implementation information to engineers building similar turbines, including Savonius, Darrieus, H-Darrieus, helix shape, V-type, and any other types of rotating rotors. The estimated capacity utilization factor (CUF) of any VAWTs, when using the proposed centrifugal mechanical controller, can be increased twice to 82% for on-land small VAWTs.

Analysis of visual risk perception model for braking control behaviour of human drivers: A literature review

In the interest of driving safety, it is essential to understand driver risk assessment to develop human-centred automated driving systems. Visual perception plays a core role in observing, analysing, and predicting driving crash risks. Furthermore, comprehensive progress of visual perception has been achieved in the development of risk perception metrics. However, it is still of interest to understand driver control behaviours, which depend on visual perception. Therefore, the objective of this literature review is to assess the potential of coupling time-remaining cues for risk perception and braking control behaviour. First, conventional risk perception metrics are classified based on trajectory, contact, and state principles, along with new analysis metrics that have been derived from conventional ones. Then, the analysis metrics are discussed based on visual perception information. Next, driver risk assessment is summarised according to the environment, driver, and object characteristics. Moreover, braking behaviour models are compared in relation to visual perception variables, action affordances, and behaviour dynamics. The current review further discusses the possibility of applying driver behaviour modelling to perception, navigation, and spatial awareness in autonomous vehicles. This human-centred approach has the potential to improve interaction between drivers and automation.

Research on particle swarm optimization algorithm of electromechanical hybrid braking control strategy based on road surface recognition

ABSTRACT Concerning the issue of low energy recovery efficiency of compound braking in Battery electric vehicles, an electromechanical composite braking control strategy based on road recognition and particle swarm optimization algorithm is proposed, which is different from the braking force control strategy of front and rear wheels with fixed ratio distribution before optimization. By analyzing the structure and working principle of the compound braking system of electric vehicle, a road surface identifier based on fuzzy algorithm is designed to track the peak adhesion coefficient of the road surface to obtain the maximum braking force of the brake. In addition, particle swarm optimization (PSO) is used to modify the motor braking force, so as to maximize the efficiency of energy recovery, and CRUISE and MATLAB are used in simulation environment to carry out joint simulation analysis. The results show that compared with the control strategy before optimization, the proposed control strategy not only ensures the vehicle braking stability but also has shorter braking distance, shorter braking time, larger motor braking torque, and slower decrease of battery State of Charge (SOC) value. Under the cycle condition of New European Driving Cycle (NEDC), Federal Test Procedure (FTP) and Extra Urban Driving Cycle (EUDC), the State of Charge of the battery increased by 1.98%, 2.1%, and 0.5%, respectively.