Hydraulic Braking Research Articles

Research on the characteristics of a pneumatic proportional valve

Abstract The execution of autonomous driving in heavy-duty trucks necessitates stringent regulation of their braking torque output. Hydraulic retarder serves as a widely auxiliary braking system in heavy-duty vehicles, with the pneumatic proportional valve functioning as the core component of its control system, regulating the output response and control precision of the braking torque of the hydraulic retarder. To improve the accuracy of brake torque control for hydraulic retarders, it is critical to conduct thorough research on the control system, especially the pneumatic proportional valve. Therefore, A detailed analysis of the working mechanism of pneumatic proportional valves was conducted, encompassing the construction of mathematical and simulation models. The efficacy of the simulation model was confirmed via experimental validation. When the control pressure increases, the simulation results are close to the experimental results, with a maximum discrepancy of 18%; when the control pressure decreases, the simulation results show a similar trend to the experimental results. The research can aid in formulating control methodologies for pneumatic proportional valves and offer theoretical guidelines for future exploration into boosting the precision of hydraulic retarder braking torque control.

Efficiency enhancement of bicycle anti-lock braking systems (ABS): Design and optimization of solenoid actuators through finite element analysis and performance simulation

The rising popularity of cycling underscores the need for enhanced safety, particularly under challenging braking conditions. This study introduces a novel high-power switch valve designed explicitly for Bicycle Hydraulic Disc Brakes (BHDBs), incorporating Hydraulic Anti-lock Braking Systems (ABS). Comprehensive Finite Element Analysis (FEA) modeling and subsequent optimization of an existing solenoid valve’s internal geometry were performed through 2D and 3D simulations to evaluate magnetic flux. The improved design achieved a maximum output force of 280 N with a linear stroke of approximately 3.5 mm. Notably, the enhanced system exhibited a 28% reduction in required current, from 5.0 to 3.6 A, a result validated through LabVIEW-equipped custom tests, which stress the credibility of the research. This study underscores significant advancements in high-power switch valves for BHDBs, promising enhanced braking efficiency and safety in high-performance, battery-powered bicycles. These findings not only promise enhanced safety for cyclists but also suggest the potential for broader application in energy-efficient and sustainable bicycle ABS technology, contributing to improved cyclist safety without compromising the environmental and health benefits of cycling. The potential impact of this research extends beyond the immediate context, offering insights that could be applied to other areas of technology and safety.

Regenerative braking fault compensation control of distributed electric vehicle considering random wheel fault degree

Distributed drive electric vehicles can reduce range anxiety through regenerative braking. However, if the wheel motor torque output fails, it will form an additional yaw moment to the vehicle, causing instability, or deviation and threatening its safety. To solve this problem, the research object is an electric vehicle driven by a four-wheel hub motor. A braking force compensation distribution strategy for front and rear axles is proposed, which combines electronic hydraulic braking (EHB) system compensation control and deviation auxiliary control. Firstly, a fault detection module is established, and the motor’s output torque is estimated by designing a torque observer to obtain the fault degree information of the motor. Secondly, to fully use the motor’s regenerative braking force, the fault-free and faulty electro-hydraulic braking force distribution strategies are designed in the coordinated distribution layer of the electro-hydraulic braking system. The corresponding electro-hydraulic braking force compensation method is selected according to the fault degree of the regenerative braking function, the position of the faulty wheel, and the braking strength. Then, a deviation auxiliary controller is designed based on the model predictive control, and the intervention time of the auxiliary controller is determined according to the vehicle’s state. Finally, the control method is verified based on CarSim/Simulink co-simulation and hardware-in-the-loop (HIL) platform. The test results show that the designed control method can effectively compensate for the regenerative braking failure of random wheel and ensure the braking safety of the vehicle.

A Study on the Design of Hydraulic Auxiliary Braking System for Commercial Vehicles

A Study on the Design of Hydraulic Auxiliary Braking System for Commercial Vehicles

Research on coordinated control strategy for braking energy recovery of pure electric vehicles based on ESC

AbstractTaking a rear‐wheel drive pure electric vehicle as the research object, considering the safety during braking and improving energy recovery rate, a study was conducted on the distribution strategy of front and rear axle braking force. During the braking process, the feedback braking force of the motor and the hydraulic braking force with an electronic stability controller (ESC) were coordinated and controlled, to ensure that the total required braking force was met. A fuzzy logic controller has been designed, with three variables of battery state of charge, vehicle speed, and braking intensity as inputs, and a modified motor braking ratio as output variable to prevent wheel lockup. Using Cruise software, a co‐simulation model was established with Amesim and Simulink, and simulation validation was conducted on the braking process and cycling conditions. The simulation results showed that the brake recovery strategy based on fuzzy control can effectively improve the vehicle's control performance and energy recovery rate compared to the Economic Commission of Europe regulation. The NEDC (New European Driving Cycle) working condition improved by 10.41% and the CLTC‐P (China Light‐duty Vehicle Test Cycle‐passenger) working condition improved by 10.57%. Effectively improving power consumption per 100 km, NEDC decreased by 1.81% and CLTC‐P decreased by 2.62%.

Simulation and analysis of the electro-hydraulic coordinated system for the disc brake system in mining belt conveyor

The present study aims to investigate the dynamic performance of the disk hydraulic brake system in a mining belt conveyor. To achieve this, a simulation model of the hydraulic system for the belt conveyor is designed and constructed using AMESim. It is recognized that brake disk deformation can lead to brake shock, thus an ADAMS rigid-flexible coupling model for hydraulic disk brakes is established. Furthermore, the concept of rigid-flexible coupling mechanical systems is introduced into the hydraulic system to enable interaction between physical quantities. Use fuzzy logic rules to adjust parameters in Simulink, and in response to the suboptimal control of braking and acceleration, a compact non-model-based adaptive algorithm is incorporated into the conventional PID control algorithm. Employing mechanical modeling and multidisciplinary dynamic collaborative simulation technology, a simulation system integrating electromechanical and hydraulic aspects is developed for the disk hydraulic brake of belt conveyors. This system is employed to conduct simulation studies on the closed-loop control of braking disk speed and deceleration/acceleration for belt conveyors. The study findings reveal that the non-model-based adaptive PID control algorithm, in comparison to fuzzy PID, not only demonstrates quicker and more stable responses across various dynamic performance curves but also markedly reduces the axial oscillation amplitude of the braking disk under braking conditions.

The study of multi-discs hydraulic brake pressure dynamic characteristics

Abstract The pressure dynamic characteristics of hydraulic brakes directly impact the efficiency of the brake control system and aircraft stop distance. A simulation model of hydraulic brake is established with Simulink software. The simulation results are compared with the test results, which proves the reliability of the analysis model. The simulation results visually give the microscopic process of pressure rise and fall in the brake assembly. The study of dynamic characteristics is performed with the correlated simulation model to figure out the reasons for the slow rate of pressure rise and fall, for which suggestions are proposed for future system design improvements.

RBS and ABS Coordinated Control Strategy Based on Explicit Model Predictive Control.

During the braking process of electric vehicles, both the regenerative braking system (RBS) and anti-lock braking system (ABS) modulate the hydraulic braking force, leading to control conflict that impacts the effectiveness and real-time capability of coordinated control. Aiming to enhance the coordinated control effectiveness of RBS and ABS within the electro-hydraulic composite braking system, this paper proposes a coordinated control strategy based on explicit model predictive control (eMPC-CCS). Initially, a comprehensive braking control framework is established, combining offline adaptive control law generation, online optimized control law application, and state compensation to effectively coordinate braking force through the electro-hydraulic system. During offline processing, eMPC generates a real-time-oriented state feedback control law based on real-world micro trip segments, improving the adaptiveness of the braking strategy across different driving conditions. In the online implementation, the developed three-dimensional eMPC control laws, corresponding to current driving conditions, are invoked, thereby enhancing the potential for real-time braking strategy implementation. Moreover, the state error compensator is integrated into eMPC-CCS, yielding a state gain matrix that optimizes the vehicle braking status and ensures robustness across diverse braking conditions. Lastly, simulation evaluation and hardware-in-the-loop (HIL) testing manifest that the proposed eMPC-CCS effectively coordinates the regenerative and hydraulic braking systems, outperforming other CCSs in terms of braking energy recovery and real-time capability.

Variable Universe Fuzzy-Proportional-Integral-Differential-Based Braking Force Control of Electro-Mechanical Brakes for Mine Underground Electric Trackless Rubber-Tired Vehicles.

Currently, the main solution for braking systems for underground electric trackless rubber-tired vehicles (UETRVs) is traditional hydraulic braking systems, which have the disadvantages of hydraulic pressure crawling, the risk of oil leakage and a high maintenance cost. An electro-mechanical-braking (EMB) system, as a type of novel brake-by-wire (BBW) system, can eliminate the above shortcomings and play a significant role in enhancing the intelligence level of the braking system in order to meet the motion control requirements of unmanned UETRVs. Among these requirements, the accurate control of clamping force is a key technology in controlling performance and the practical implementation of EMB systems. In order to achieve an adaptive clamping force control performance of an EMB system, an optimized fuzzy proportional-integral-differential (PID) controller is proposed, where the improved fuzzy algorithm is utilized to adaptively adjust the gain parameters of classic PID. In order to compensate for the deficiency of single-close-loop control and adjusting the brake gap automatically, a cascaded three-closed-loop control architecture with force/position switch technology is established, where a contact point detection method utilizing motor rotor angle displacement is proposed via experiments. The results of the simulation and experiments indicate that the clamping force response of the proposed multi-close-loop Variable Universe Fuzzy-PID (VUF-PID) controller is faster than the multi-closed-loop Fuzzy-PID and cascaded three-close-loop PID controllers. In addition, the chattering of braking force can be suppressed by 17%. This EMB system may rapidly and automatically finish the operation of the overall braking process, including gap elimination, clamping force tracking and gap recovery, which can obviously enhance the precision of the longitudinal motion control of UETRVs. It can thus serve as a BBW actuator of mine autonomous driving electric vehicles, especially in the stage of braking control.

ELECTROMAGNETIC BRAKING SYSTEM

In this paper, we delve into the intricacies of Electromagnetic Braking systems and their influence on traditional braking methods. Ensuring driver safety and comfort on the road is paramount for any braking system. Conventional braking systems, including Drum Brakes, Disc Brakes, Hydraulic Brakes, and Pneumatic Brakes, rely on friction to decelerate vehicles, leading to heat generation and wear on braking components, thereby diminishing efficiency over time. Electromagnetic Braking emerges as a viable alternative, boasting superior efficiency characterized by a high power-to-torque ratio and reduced friction. This paper examines the transition to electromagnetic braking and its implications for conventional braking methodologies. Keywords: Electromagnetic Braking; Traditional Braking; Friction; Heat Generation; Efficiency.

Research on the Comprehensive Allocation Method for a Vehicle Hydraulic Braking System Based on Partial Fuzzy Ratings and Considering Failure Correlation

Research on the Comprehensive Allocation Method for a Vehicle Hydraulic Braking System Based on Partial Fuzzy Ratings and Considering Failure Correlation

Enhanced Estimation of Clamping-Force for Automotive EMB Actuators Using a Switching Extended State Observer

The automotive intelligence and electrification require the braking system to cooperate with the controller to achieve regenerative and active braking functions. Hence, the range and driving safety of the electric vehicles are improved. Electromechanical Brake (EMB) systems completely abandon the fluid and hydraulic elements and replace the traditional hydraulic braking system with a wire harness and electromechanical parts. The braking torque adjustment is achieved entirely by controlling the four-wheel EMBs. At present, reliability and fault tolerance are the key technical issues associated with EMBs. To eliminate the need of any clamping-force sensor due to its vulnerability and high cost, in this paper, a switching extended state observer (SESO) is presented to provide rapid force estimation with higher precision. The substrates of the internal linear and nonlinear structures have been unified into a single form by using an equivalent gain method. The SESO is effective to detect the initial contact between the braking disk and pad by estimating the load torque. It is experimentally verified that the developed force sensorless control strategy is accurate and superior to the existing techniques.

On Torque Vectoring Control: Review and Comparison of State-of-the-Art Approaches

Torque vectoring is a widely known technique to improve vehicle handling and to increase stability in limit conditions. With the advent of electric vehicles, this is becoming a key topic since it is possible to have distributed powertrains, i.e., multiple motors are adopted, in which each motor is controlled separately from the others. Moreover, electric motors deliver the torque required by the controller faster and more precisely than internal combustion engines, active differentials and conventional hydraulic brakes. The state of the art of Direct Yaw Moment Control (DYC) techniques, ranging from classical to modern control theories, are analyzed and discussed in this paper. The aim is to give an overview of the currently available approaches while identifying their drawbacks regarding performances and robustness when dealing with common issues like model uncertainties, external disturbances, friction limit and common state estimation problems. This contribution analyzes all the steps from the lateral dynamics reference generation to the desired control action computation and allocation to the available actuators. In addition, some of the presented control logic is evaluated in a simulation environment for a passenger car. Results of both open-loop and closed-loop maneuvers allow the comparison and clarification of each control strategy’s key advantages.

Research on the Multi-Mode Composite Braking Control Strategy of Electric Wheel-Drive Multi-Axle Heavy-Duty Vehicles

Electric wheel-drive multi-axle heavy-duty vehicles have the characteristics of strong maneuverability and good passability, thereby they are widely used in heavy equipment transportation. However, current research on the composite braking of multi-axle heavy-duty vehicles is rare, which is not conducive to improving braking performance and braking energy utilization efficiency. This work proposes a multi-mode composite braking control strategy for the five-axle distributed electric wheel-drive heavy-duty vehicle. Firstly, given the differences in braking dynamics between two-axle vehicles and multi-axle vehicles, the brake dynamics characteristics of multi-axle vehicles are analyzed, and the vehicle dynamics model of multi-axle vehicles is constructed. Next, a multi-mode composite braking control strategy including a fully electric braking state and hybrid electro–hydraulic braking state is proposed in order to improve the braking energy recovery and braking stability. Finally, a hardware-in-the-loop simulation system is established, and the single-braking conditions and China heavy-duty commercial vehicle test cycle-heavy truck (abbreviated as CHTC-HT) are conducted to verify the performance of the braking control strategy. The results indicate that the recaptured braking energy and braking stability are significantly increased by applying the control strategy proposed in this work.

Simulation Study on Hydraulic Braking Control of Engine Motor of Hybrid Electric Vehicle

Abstract Taking the hybrid electric vehicle as the research object, under the premise of ensuring braking safety, aiming at maximizing the use of motor regenerative braking force and improving the coordination performance of motor hydraulic braking, a simulation study of motor hydraulic braking control based on hybrid electric vehicle engine is proposed. According to the dynamic model and ideal braking force distribution curve of the hybrid electric vehicle, combined with the common idea of electro-hydraulic compound braking force distribution, a three-layer braking control structure of the hybrid electric vehicle is constructed. The management determines the braking intention through the driver's pedal action and calculates the expected torque, and the control layer obtains the target braking force distribution relationship through the logic gate limit control method based on the expected torque. According to the actual motor torque signal fed back by the executive layer and the wheel cylinder pressure signal of the hydraulic braking system, the braking force and regenerative braking force of the hydraulic system are dynamically coordinated and controlled to ensure that the state switching of each component can be rapid, stable, and timely, and the control instruction is transmitted to the motor hydraulic braking system of the executive layer through the vehicle controller to complete the motor hydraulic braking of the hybrid electric vehicle engine. The experimental results show that this method can realize the reasonable distribution of motor hydraulic braking under different braking intensities, different initial braking speeds, and different pedal dip amplitudes, which makes the reaction speed of the hybrid electric vehicle in the braking process faster, the braking switching more stable and safe, effectively improves the energy utilization rate of the hybrid electric vehicle, and ensures the economy and safety of braking control of the hybrid electric vehicle.

Estimation of Wheel Pressure for Hydraulic Braking System by Interacting Multiple Model Filter

Estimation of Wheel Pressure for Hydraulic Braking System by Interacting Multiple Model Filter

Analysis of vehicle braking dynamics with hydraulic braking system

The stopping distance in vehicle is the distance require to safely stop after the driver has applied the brakes of vehicle. The stopping distance varies from road types to experience of driver. The objective of this study is to determine the stopping distance of vehicle for two different road condition: dry asphaltic and wet asphaltic. The methodology includes studying various factors involve in braking dynamics and validating the analytical calculation with Numerical methods. The velocity in which vehicle is travelling, coefficient of friction between road and vehicle tire plays important role in calculation of stopping distance. It was found that during wet season the stopping distance increased from 89 m to 99 m for vehicle travelling at 100 km/hr. The stopping time obtained from simulation in CarSim was 5.1 seconds for dry road and 6.4 seconds for wet road conditions.

Research on hydraulic braking energy recovery system of heavy vehicles

The carbon emission of a heavy-duty diesel vehicle is almost equal to the sum of 100 small cars. In the global environment where energy conservation and emission reduction are advocated, the pollution caused by heavy vehicles is non-negligible. A hydraulic brake energy recovery and regeneration system can store the braking energy, convert the energy into kinetic energy and output it to the vehicle transmission system when starting or accelerating, thereby reducing energy consumption and achieving the role of energy conservation and emission reduction. Firstly, this paper mainly summarizes several vehicle energy recovery technology schemes and determines the hydraulic braking energy recovery scheme after a comprehensive comparison. Secondly, the overall structure of the hydraulic brake energy recovery and regeneration system is designed, and the working mode is analyzed. Finally, according to the working characteristics of the main components in the system, the mathematical model is established, the key parameters are simulated and studied, and the appropriate selection and matching scheme is provided.

Simulation of motor vehicle brake pressure monitoring system

The braking system is a system that is always evolving to improve safety and security in driving so as to minimize the number of accidents. The braking system aims to reduce speed and stop the vehicle. This study uses a simulation on the MATLAB Simulink. The purpose of this research is to find out how the braking system works to improve safety for riders. The principle of the hydraulic braking system is to work according to Pascal's law where fluid is used to continue the braking force of the brake pedal being pressed towards the master cylinder to produce brake pressure. This research begins by making equations in hydraulic braking followed by making a Simulink block braking system. Based on the research, data on the comparison of the number of vehicle loads on the braking system and comparison data on the variation of road conditions on the braking system show that if the vehicle load is heavier, the time needed to stop is longer, the braking pressure is greater, and the distance needed to stop is greater. If the road adhesion coefficient is smaller, the time needed to stop is longer and the distance needed to stop is greater.

Electro-hydraulic composite stability control for regenerative braking failure of in-wheel motors drive electric vehicle

The in-wheel motor simplifies the structure of drive system and improves dynamic performance of vehicle. However, the regenerative braking failure of unilateral motor could greatly reduce braking strength and cause the instability of vehicle. The existing control methods are difficult to guarantee the braking performance and driving stability at the same time. To resolve this fail-safe problem, an electro-hydraulic composite stability control method is proposed and verified. Firstly, the vehicle model, the in-wheel motor model, and the hydraulic braking system model are built. Secondly, the electro-hydraulic composite stability control method is proposed and a stability controller based on model predictive control algorithm is designed to solve the problems of model uncertainty and external interference in the control process. Thirdly, the control effect of proposed method is compared with torque truncation control, hydraulic compensation control, and yaw stability control. Finally, the electro-hydraulic composite stability control method proposed in this paper is verified and tested on the real vehicle. The results show that the combination of the torque truncation control, the hydraulic compensation control, and yaw stability control could improve the driving stability of vehicle and meet the demand of braking intensity.