Anti-skid Braking System Research Articles

Flight tests study of aircraft anti-skid braking system

Flight tests study of aircraft anti-skid braking system

Cascaded fast terminal sliding mode control for UAV electric braking system

The anti-skid braking system of unmanned aerial vehicle has the characteristics of high-order nonlinearity, strong coupling, and time-varying parameters, which will seriously affect the taxiing performance of the unmanned aerial vehicle. This paper proposed a cascaded fast terminal sliding mode control method for unmanned aerial vehicle electric braking system, which can accurately track the optimal slip rate and ensure the stability of the braking system. First, the electric braking system model of unmanned aerial vehicle is established, which gets rid of the reliance on the ground binding coefficient fitting formulas. Second, combined with the concept of the inversion control, the cascaded fast terminal sliding mode controller is designed to achieve the accurate tracking of the slip rate and the reference braking force. The stability of the controller is proved by the Lyapunov stability theory. Finally, the effectiveness of the proposed control strategy is verified by simulation results.

Design and Co-simulation of an Antiskid Brake System for a Civil Aircraft

Design and Co-simulation of an Antiskid Brake System for a Civil Aircraft

A novel aircraft anti-skid brake control method based on multi-objective model predictive control for suppressing landing gear walk vibration

To suppress the longitudinal landing gear vibration (gear walk) induced by the aircraft anti-skid braking system (ABS), an aircraft ABS control method based on multi-objective model predictive control (MPC) is proposed. The landing gear is simplified to be a cantilever beam with tip mass to analyze the vibration mechanism, based on which a low-order model to describe both the braking dynamics and the gear walk dynamics is derived. The multi-objective ABS controller is then designed to achieve landing gear walk suppression as well as to ensure the braking efficiency, simultaneously. Considering that the aircraft ABS is a strongly nonlinear system with demanding real-time requirements, the successive linearization based MPC (SLMPC) method is employed to reduce the computational burden. To comply with the SLMPC design, a tire-road friction parameter identification method by combining the extended Kalman filter (EKF) and linearized recursive least squares (LRLS) is also proposed. Finally, the effectiveness of the proposed control method is verified through both simulation and experimental studies, which demonstrate the good performance of the proposed method.

Application of Deep Reinforcement Learning in Reconfiguration Control of Aircraft Anti-Skid Braking System

The aircraft anti-skid braking system (AABS) plays an important role in aircraft taking off, taxiing, and safe landing. In addition to the disturbances from the complex runway environment, potential component faults, such as actuators faults, can also reduce the safety and reliability of AABS. To meet the increasing performance requirements of AABS under fault and disturbance conditions, a novel reconfiguration controller based on linear active disturbance rejection control combined with deep reinforcement learning was proposed in this paper. The proposed controller treated component faults, external perturbations, and measurement noise as the total disturbances. The twin delayed deep deterministic policy gradient algorithm (TD3) was introduced to realize the parameter self-adjustments of both the extended state observer and the state error feedback law. The action space, state space, reward function, and network structure for the algorithm training were properly designed, so that the total disturbances could be estimated and compensated for more accurately. The simulation results validated the environmental adaptability and robustness of the proposed reconfiguration controller.

An aircraft landing gear walk suppression method based on runway identification

The main landing gear walk is a longitudinal fore and aft movement of the strut caused by the brake system, and usually the vibration frequency does not exceed 10Hz. Gear walk is not only detrimental to the structural safety of the landing gear but also impairs the aircraft braking system's efficiency, so this vibration must be suppressed. Conventional anti-skid braking system (ABS) cannot recognize the friction characteristics of the tires and the road, so the tire-road friction changes drastically, which is the direct reason for gear walk. To address this problem, this paper first proposes a runway identification method to determine the optimal slip ratio for different runways, thereby achieving efficient anti-skid control and avoiding drastic changes in tire-road friction. A common anti-skid braking algorithm used in aircraft today is the pressure-bias modulation (PBM) algorithm, which is a rule-based deceleration-rate type of anti-skid algorithm. To solve the problem of landing gear vibration caused by unstable brake pressure of PBM, this paper proposes a slip-ratio based antiskid control method based on the super twist algorithm (STA). We constructed a simulation model in MATLAB/Simulink and conducted simulation tests, and the simulation results proved that the gear walking suppression method is effective.

Analysis of anti-skid braking efficiency calculation method

In order to calculate anti-skid braking system efficiency, torque method and wheel slip method are usually introduced and recommended to take. This paper analyses theoretically the two methods, based on braking system experience. Some parameters are clarified to make the two methods to be implemented easily. Calculating results are also provided to make readers have clear understanding and deep cognition for the calculating process. By some comparison and analysis, a better method is proposed to show compliance to related aviation authority.

Maneuvering characteristics and influence of aircraft anti-skid braking system

The ultimate goal of air transport is to promote safety, economy and comfort. The requirements and effects of safety, economy and comfort of aircraft anti-skid braking system is proposed in this paper. Based on the perspectives of the airport operating environment, and the configuration characteristics of aircraft anti-skid braking system, the influence of anti-skid brake characteristics in its service life is analyzed. Some anti-skid brake auxiliary operation modes and precautions are summarized.

Design of an NSMCR Based Controller for All-Electric Aircraft Anti-Skid Braking System

In this paper, a relative threshold event-triggered based novel complementary sliding mode control (NSMCR) algorithm of all-electric aircraft (AEA) anti-skid braking system (ABS) is proposed to guarantee the braking stability and tracking precision of reference wheel slip control. First, a model of the braking system is established in strict-feedback form. Then a virtual controller with a nonlinear control algorithm is proposed to address the problem of constraint control regarding wheel slip rate with asymptotical stability. Next, a novel approaching law-based complementary sliding mode controller is developed to keep track of braking pressure. Moreover, the robust adaptive law is designed to estimate the uncertainties of the braking systems online to alleviate the chattering problem of the braking pressure controller. Additionally, to reduce the network communication and actuator wear of AEA-ABS, a relative threshold event trigger mechanism is proposed to transmit the output of NSMC in demand. The simulation results under various algorithms regarding three types of runway indicate that the proposed algorithms can improve the performance of braking control. In addition, the hardware-in-the-loop (HIL) experimental results prove that the proposed methods are practical for real-time applications.

PSO Optimized Active Disturbance Rejection Control for Aircraft Anti-Skid Braking System

A high-quality and secure touchdown run for an aircraft is essential for economic, operational, and strategic reasons. The shortest viable touchdown run without any skidding requires variable braking pressure to manage the friction between the road surface and braking tire at all times. Therefore, the manipulation and regulation of the anti-skid braking system (ABS) should be able to handle steady nonlinearity and undetectable disturbances and to regulate the wheel slip ratio to make sure that the braking system operates securely. This work proposes an active disturbance rejection control technique for the anti-skid braking system. The control law ensures action that is bounded and manageable, and the manipulating algorithm can ensure that the closed-loop machine works around the height factor of the secure area of the friction curve, thereby improving overall braking performance and safety. The stability of the proposed algorithm is proven primarily by means of Lyapunov-based strategies, and its effectiveness is assessed by means of simulations on a semi-physical aircraft brake simulation platform.

Robust Self-Learning PID Control of an Aircraft Anti-Skid Braking System

In order to deal with strong nonlinearity and external interference in the braking process, this paper proposes a robust self-learning PID algorithm based on particle swarm optimization, which does not depend on a precise mathematical model of the controlled object. The self-learning function is used to adapt to the diversity of the runway road surface friction, the particle swarm algorithm is used to optimize the rate of self-learning, and robust control is used to deal with the modeling uncertainty and external disturbance of the system. The convergence of the control strategy is proved by theoretical analysis and simulation experiments. The superiority and accuracy of the method are verified by NASA ground test results. The simulation results shows that the adverse effect of the external disturbance is suppressed, and the ideal trajectory is tracked.

Multiphase-Based Optimal Slip Ratio Tracking Control of Aircraft Antiskid Braking System via Second-Order Sliding-Mode Approach

This article addresses a novel multiphase-based real-time optimal slip ratio tracking control problem of an aircraft antiskid braking system (ABS) based on the second-order sliding-mode approach. First, a comprehensive dynamic model of an aircraft ABS is established, in which the coupling mechanism of the longitudinal, the vertical, and the pitching dynamics of the aircraft are thoroughly considered. Second, for the aircraft ABS with high nonlinearity, since the measurements of aircraft velocity and acceleration cannot be transmitted to the aircraft ABS in time, the second-order sliding-mode differentiator (SMD) will be designed to estimate them simultaneously. Then, the optimal slip ratio signal, which formulates the maximum friction coefficient, will be updated based on the static friction coefficient model with real-time measured and estimated signals. Furthermore, a novel multiphase-based slip ratio regulation algorithm integrated with the second-order sliding-mode control strategy is proposed on the basis of runway characteristics to track the optimal slip ratio signal, which can not only stop the aircraft faster but prevent the mainwheel from final locking. Finally, the simulation results are presented to demonstrate that the aircraft antiskid braking algorithm proposed in this article can effectively prevent the mainwheel from locking under different runway conditions, and significantly improve the braking efficiency.

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.

Adaptive Fuzzy Active-Disturbance Rejection Control-Based Reconfiguration Controller Design for Aircraft Anti-Skid Braking System

The aircraft anti-skid braking system (AABS) is an essential aero electromechanical system to ensure safe take-off, landing, and taxiing of aircraft. In addition to the strong nonlinearity, strong coupling, and time-varying parameters in aircraft dynamics, the faults of actuators, sensors, and other components can also seriously affect the safety and reliability of AABS. In this paper, a reconfiguration controller-based adaptive fuzzy active-disturbance rejection control (AFADRC) is proposed for AABS to meet increased performance demands in fault-perturbed conditions as well as those concerning reliability and safety requirements. The developed controller takes component faults, external disturbance, and measurement noise as the total perturbations, which are estimated by an adaptive extended state observer (AESO). The nonlinear state error feedback (NLSEF) combined with fuzzy logic can compensate for the adverse effects and ensure that the faulty AABS maintains acceptable performance. Numerical simulations are carried out in different runway environments. The results validate the robustness and reconfiguration control capability of the proposed method, which improves AABS safety as well as braking efficiency.

Investigating the Effect of Valve Shape on Anti-Lock Braking System Plunger Pump Performance Using Fluid-Structure Interaction Simulation

An anti-lock braking system (ABS) is an anti-skid braking system commonly used as a safety feature in vehicles. The hydraulic control unit for the ABS of a vehicle includes a plunger pump between the wheel and master cylinder. This paper presents numerical investigations of the effect of valve shapes on the performance improvement provided by a plunger pump, focusing on two different valve shapes, ball-type and hat-type. Transient laminar flow analyses of plunger pumps with ball and hat-type inlet valves are performed under motor speeds from 1000 to 5000 rpm using the fluid-structure interaction (FSI) and user-defined function (UDF) techniques. An experimental verification of the simulation results for the plunger pump with a ball-type valve was conducted using the standard pump test of the Mando Corporation, South Korea. A comparison of the simulation and experimental results suggests that these are in good agreement. The simulation results indicate that the hat-type valve outperforms the ball-type valve due to a shorter delay in the closing time at the end of the suction cycle. These findings suggest that valve shape has a considerable impact on the performance improvement provided by a plunger pump, providing crucial insights into the future design of high-efficiency pumps.

Model Construction and Performance Degradation Characteristics of a Deflector Jet Pressure Servo Valve under the Condition of Oil Contamination

The deflector jet pressure servo valve is a kind of high-precision hydraulic component that can be widely used in the antiskid braking system of an aircraft. In actual service, it will be faced with extreme working conditions of gradual oil contamination, which will cause performance degradation and function maladjustment of the whole valve. To this end, the paper proposes a performance degradation characteristic analysis method. In which, firstly, the structural characteristics and working principle of the deflector jet pressure valve are analyzed; then, the entire dynamics model of the pressure valve is built using the braking cavity as the load blind cavity. Secondly, the two main failure modes induced by oil contamination such as erosion wear of pilot stage and stuck of slide valve stage’s valve core are determined based on the engineering experience, aimed at which the failure mechanism is analyzed; then, the sensitivity simulation model of the servo valve’s output pressure with respect to key degradation parameters is established and the sensitivity analysis is performed. Finally, combining the theoretical analysis with multiphysics simulation correction methods, the performance degradation model of the typical failure modes are established, and then, the performance degradation characteristics under dynamic contamination conditions are analyzed, which is combined with the failure threshold determined by the dynamics simulation to finish the service life prediction of the deflector jet servo valve.

Design and Stability Analysis of High-Speed Unmanned Aerial Vehicle Electric Anti-Skid Braking System

A new combined electric anti-skid braking system of a high-speed unmanned aerial vehicle is designed to improve the stability and to reduce the system sensor noise. An electric anti-skid braking mechanism model considering the sensor noise effect is built in MATLAB/Simulink. The stability of a slip ratio braking system and a deceleration braking system is analyzed using the Routh criterion and Lyapunov stability method. Then the UAV ground taxiing dynamic model is built in LMS Virtual. Lab Motion. The braking performance and dynamic responses are studied under the control of the designed braking system using a co-simulation method. Conclusions show that the designed braking control system can solve the sensor noise problem effectively and the stability and robustness are both ensured under this control law.

Experimental investigation on wheel–rail adhesion characteristics under water and large sliding conditions

Purpose The purpose of this study is to investigate the adhesion characteristics of the wheel–rail under water and large sliding conditions. This is carried out by conducting a series of tests on a full-scale roller rig. The measured data provides an experimental base for conducting further theoretical research. Design/methodology/approach The influence of the slip ratio, rolling speed and the axle load on the adhesion coefficient between the wheel and the rail is analyzed under wet conditions using a full-scale roller rig. Findings From the research, it is found that the adhesion coefficient–slip ratio curve varies from the traditional theoretical description under water and large sliding conditions. Moreover, it is also observed that after the adhesion coefficient reaches the saturation point, the adhesion coefficient does not decrease, but continues to increase as the slip ratio increases. Originality/value The adhesion improvement phenomenon in this paper may provide new ideas for designing anti-skid control and braking system mechanisms for trains. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0236/

Qualitative Validation Approach Using Digital Model for the Health Management of Electromechanical Actuators

An efficient and all-inclusive health management encompassing condition-based maintenance (CBM) environment plays a pivotal role in enhancing the useful life of mission-critical systems. Leveraging high fidelity digital modelling and simulation, scalable to digital twin (DT) representation, quadruples their performance prediction and health management regime. The work presented in this paper does exactly the same for an electric braking system (EBS) of a more-electric aircraft (MEA) by developing a highly representative digital model of its electro-mechanical actuator (EMA) and integrating it with the digital model of anti-skid braking system (ABS). We have shown how, when supported with more-realistic simulation and the application of a qualitative validation approach, various fault modes (such as open circuit, circuit intermittence, and jamming) are implemented in an EMA digital model, followed by their impact assessment. Substantial performance degradation of an electric braking system is observed along with associated hazards as different fault mode scenarios are introduced into the model. With the subsequent qualitative validation of an EMA digital model, a complete performance as well as reliability profile of an EMA can be built to enable its wider deployment and safe integration with a larger number of aircraft systems to achieve environmentally friendly objectives of the aircraft industry. Most significantly, the qualitative validation provides an efficient method of identifying various fault modes in an EMA through rapid monitoring of associated sensor signals and their comparative analysis. It is envisaged that when applied as an add-on in digital twin environment, it would help enhance its CBM capability and improve the overall health management regime of electric braking systems in more-electric aircraft.

Backstepping Fuzzy Sliding Mode Control for the Antiskid Braking System of Unmanned Aerial Vehicles

This paper proposes a backstepping fuzzy sliding mode control method for the antiskid braking system (ABS) of unmanned aerial vehicles (UAVs). First, the longitudinal dynamic model of the UAV braking system is established and combined with the model of the electromechanical actuator (EMA), based on reasonable simplification. Subsequently, to overcome the higher-order nonlinearity of the braking system and ensure the lateral stability of the UAV during the braking process, an ABS controller is designed using the barrier Lyapunov function to ensure that the slip ratio can track the reference value without exceeding the preset range. Then, a power fast terminal sliding mode control algorithm is adopted to realize high-performance braking pressure control, which is required in the ABS controller, and a fuzzy corrector is established to improve the dynamic adaptation of the EMA controller in different braking pressure ranges. The experimental results show that the proposed braking pressure control strategy can improve the servo performance of the EMA, and the hardware in loop (HIL) experimental results indicate that the proposed slip ratio control strategy demonstrates a satisfactory performance in terms of stability under various runway conditions.