Innovative braking system for high-speed 80-foot platform

The article discusses technical solutions for the creation of an effective design of a brake system for high-speed longwheelbase platforms intended for the transport of containers, as well as for the development of a fundamentally new brake equipment for the pneumatic, electro-pneumatic and mechanical parts of the brake system. Modular braking equipment for the pneumatic and electro-pneumatic parts of the high-speed platform braking system, compactly located under the platform frame, provides technical compatibility when controlling platform brakes as part of not only a high-speed freight train of permanent formation, but also in trains for other purposes, regardless of the location of the platform in the composition of the train. The performance of the braking equipment of each platform in motion and in the parking lot is monitored using pressure sensors and an electronic unit that processes the readings of the sensors and transmits information to the locomotive via one of the wire lines of the electro-pneumatic brake. The brake rigging used on the high-speed platform is arranged in the design of three-axle bogies and provides doublesided pressing on the wheels with typical composite brake pads, automatic regulation and maintenance of the standard clearances between brake pads and wheels. The proposed promising technical solutions make it possible to continuously diagnose the parameters of the brakes of each platform as part of a permanent train, display them on the locomotive monitor and transmit them to the dispatch centers of the Russian Railways infrastructure. Thanks to this, the braking effciency can be increased and the safety of train traffc can be ensured while increasing the permissible travel speeds. In the modern concept of digitalization of the infrastructure of Russian Railways, which provides for the creation in 2021–2025 (and in the future until 2030) of cars in which intelligent technologies should be applied, the braking system of a high-speed platform can be considered as the basis for creating a digitally controlled train — one of the key elements of the digital railway.

THE IMPROVEMENT MECHANICAL BRAKE SYSTEM OF THE PASSENGER СAR

A set of theoretical scientific researches is carried out in the work, which proves that with the use of different types of brake pads in passenger cars some elements of the typical design of the mechanical brake system need to be modernized. Analytical calculations of the brake lever transmission of passenger cars are performed on the basis of the 2D scheme-model. Due to this, ways to improve the most important elements of lever transmission in passenger cars under the conditions of composite pads are proposed. The analysis of the forces acting in the typical design of the lever transmission of a passenger car for different types of pads is performed. The strength of important elements of the mechanical brake system is calculated by applying the finite element method. It is proposed to use the capabilities of the software package Femap Siemens PLM Software, which allows you to optimize the elements of the mechanical system of passenger cars. An example of topological optimization of some elements of brake lever transmission of a passenger car is given. By improving the elements of the mechanical brake system for the use of composite pads in passenger cars, greatly simplifies their design, facilitates maintenance and repair, also reduces the weight of the system as a whole and cost and significantly increases the level of traffic safety.

Sensor Fault Diagnosis of Locomotive Electro-Pneumatic Brake Using an Adaptive Unscented Kalman Filter

Normal operation of the pressure sensor is important for the safe operation of the locomotive electro-pneumatic brake system. Sensor fault diagnosis technology facilitates detection of sensor health. However, the strong nonlinearity and variable process noise of the brake system make the sensor fault diagnosis become challenging. In this paper, an adaptive unscented Kalman filter- (UKF-) based fault diagnosis strategy is proposed, aimed at detecting bias faults and drift faults of the equalizing reservoir pressure sensor in the brake system. Firstly, an adaptive UKF based on the Sage-Husa method is applied to accurately estimate the pressure transients in the equalizing reservoir of the brake system. Then, the residual is generated between the estimated pressure by the UKF and the measured pressure by the sensor. Afterwards, the Sequential Probability Ratio Test is used to evaluate the residual so that the incipient and gradual sensor faults can be diagnosed. An experimental prototype platform for diagnosis of the equalizing reservoir pressure control system is constructed to validate the proposed method.

Learning-based fault diagnosis of air brake system using wheel speed data

Faults in the air brake system used in Heavy Commercial Road Vehicles (HCRVs) would adversely affect the vehicle’s dynamic performance, and hence their prompt detection is critical for vehicle safety. This paper first investigates the effect of air brake system faults through extensive hardware-in-loop experiments. These faults were observed to degrade the braking response, yaw stability, and vehicle braking distance. In many countries, an antilock brake system is mandatory in HCRVs, and wheel speed data are readily available. Inspired by this, the feasibility of using wheel speed data to detect faults is investigated in this study. As an initial step of predictive maintenance, a fault diagnostic scheme based on a supervised learning algorithm, Support Vector Machine (SVM) that uses only wheel speed data has been developed. The SVM algorithm’s efficacy was tested for 1937 test cases that encompassed a wide range of operating conditions. It was found that a Gaussian kernel SVM (G-SVM) provided a good classification accuracy of 96.54%, demonstrating its ability to predict a faulty condition accurately. The standard deviation of G-SVM’s prediction accuracy for five groups of data sets with 100 instances was found to be 1.57%, which shows that the model is more precise to predict the fault/no-fault condition of the air brake system.

Multi Scale Modelling of Friction Induced Vibrations at the Example of a Disc Brake System

Friction induced vibrations such as brake squealing, or juddering are still challenging topics in product engineering processes. So far, this topic was particularly relevant for the automobile industry because they were the main market for disc brake systems. However, since mobility habits change, disc brake system are more often to be found on bikes or e-scooters. In all of these systems, vibrations are excited in contacts on the micro scale but affect the user comfort and safety on the macro scale. Therefore, the aim of this cross-scale method is to analyze a system on a micro scale and to transfer the excitation mechanisms on a macro scale system. To address both scales, the current work presents a finite element model on the micro scale for the determination of the coefficient of friction, which is transferred to the macro scale and used in a multi-body simulation. Finally, a finite element modal analysis is conducted, which allowed us to evaluate the brake system behavior on base of an excitation.

Study on the influence of radial stiffness on the nonlinear vibration of brake system

Purpose A dynamic model of the brake system considering the tangential and radial motion of the pad, and the torsion and wobbling motion of the disk is established in this paper. The influence of radial stiffness on the brake system is investigated under different tribological conditions. This paper aims to prove that sufficient radial stiffness is indispensable in the design of the brake system with good tribological performance. Design/methodology/approach By using the lumped mass method, a dynamic model of the brake system is established. A Stribeck-type friction model is applied to this model to correlate the frictional velocity, pressure and friction force. The stability of pad vibration is analysed by analysis methods. A new stability evaluation parameter is proposed to study the influence of radial stiffness on stability of pad vibration in a certain friction coefficient brake pressure range. Findings The findings show that the tangential vibration of the pad transits from periodic motion to quasi-periodic motion under a low tangential stiffness. The influence of radial stiffness on motion stability is stronger under a low nominal brake radius. The stability of the brake system can be ensured when the brake radius and radial stiffness are sufficient. Originality/value The influence of tangential stiffness of pad on stability of the brake system has been researched for decades. The insufficiency of stiffness in radial direction may also generate certain levels of instabilities but has not been fully investigated by modelling approach. This paper reveals that this parameter is also strongly correlated to nonlinear vibration of the brake pad.