Wheeled Vehicles Research Articles

Friction mechanisms of brake pads made of cast iron and composite material on the surface of railway wheels

The friction mechanisms of brake pads made of cast iron and composite material (rubber-asbestos or rubber-free mixtures, including those with cast-iron inserts) on the surface of wheels of railway rolling stock were analysed. Values of the friction coefficient are given. The main role in the mechanism of friction of cast iron pads on the surface of railway wheels belongs to the microstructure of cast iron, namely, the amount, shape, distribution in volume of graphite inclusions, dispersion of pearlite and cementite inclusions, and the construction of phosphide eutectics. The friction mechanism of pads made of composite material on the wheel surface is determined by the content and properties of the components from which the composite rubber mixture is formed, their chemical and granulometric composition, as well as the degree of burnout of the composite rubber mixture during the operation of the brake pads. It is shown that due to the lack of regulation in the standards and technical conditions for composite blocks of the percentage content of ingredients and their chemical composition in the composite material, its properties and the value of the coefficient of friction are uncontrolled. Cyclic temperature changes on the contact surface of the brake pads with the wheels during train braking and high peak temperatures (up to 800 °C) in individual periods of braking lead to changes in the structure and properties of the surface layer of the metal of the wheels and the material of the brake pads. This is reflected in the frictional characteristics of the friction process of brake pads with wheels. The disadvantage of brake pads made of composite material is their low thermal conductivity compared to cast iron pads. As a result, the temperature in the contact zone of composite pads with wheels increases more than when using pads made of cast iron. The hydrodynamic effects of moisture (water) in the contact zone of brake pads with the surface of vehicle wheels are considered from the standpoint of classical tribology approaches. The microrelief of the working surface of the brake pads was studied. The influence of various factors on the coefficient of friction of the brake pads on the surface of the wheels is shown. Recommendations are provided for improving standards and technical conditions for brake pads made of cast iron and other materials. Keywords: brake pads, wheels of railway transport, friction, cast iron, composite materials, surface microrelief.

Robust adaptive sliding mode control for path tracking of unmanned agricultural vehicles

In this paper, a novel adaptive sliding mode control (ASMC) for path tracking of unmanned agricultural vehicles is proposed. It is shown that the designed ASMC is capable of driving the closed-loop lateral position error dynamics to converge to zero asymptotically, where the sliding mode observer (SMO) is designed to estimate the system state so as to adaptively adjust the uncertain bounds of cornering stiffness. Compared with the classical sliding mode control technique, the proposed ASMC not only guarantees strong robustness with respect to parameter uncertainties, disturbance and varying road conditions, but also requires no prior knowledge of the road information. Simulation and experimental results from a typical agricultural wheeled vehicle are provided to verify the excellent performance of the proposed scheme.

Совершенствование методики расчета крепления колесной техники на открытом железнодорожном подвижном составе

Purpose: The issues to provide safety and security of wheeled vehicles transportation on open rolling stock of railways are considered. It’s been established that calculation method does not take into account fully the interaction of bracing elements with wheeled vehicles, placed in a car, as well as the absence or non-actuation of brakes (brake system faulty state). New calculated scheme is proposed for determining the loading of the elements of wheeled vehicles bracing that does not contradict existing regulatory documents. Methods: Analysis and synthesis methods, theoretical mechanics methods were applied. Results: Improved methodology for calculating the bracing of wheeled vehicles on open rolling stock is proposed that takes into account wheels unbraked state. Practical significance: The proposed methodology for calculating the bracing of unbraked wheeled vehicles on open rolling stock takes into account the parameters of friction coefficient of a wheel, the placement and estimated effort in tie-rods. The methodology was tested during wheeled vehicles transportations from Oktyabrskaya railway stations of “Russian Railways” JSC branch.

Design and Assessment of an Anti-lock Braking System Controller

"The anti-lock braking system is a safety equipment that prevents the vehicle wheels from locking up under emergency, panic, or harsh braking conditions, ensuring steering control during braking and reducing braking distance. This system is studied by automotive engineers for performance comparisons and for determining optimal control methods. For this reason, this paper presents a method to mathematically model the anti-lock braking system. The obtained model is afterwards used inside a Simulink simulation to investigate the results with and without the anti-lock braking system and to propose a three-position regulator instead of the generally used bang-bang controller. The simulation results show the improvement of the vehicle braking time and braking distance."

IMPROVEMENT OF THE METHOD OF TESTING THE DYNAMIC PROPERTIES OF WHEELED MACHINES WITH THE USE OF ARTIFICIAL INTELLIGENCE

The method of testing vehicles for dynamic position stability has been improved, which makes it possible to assesstheir lateral stability when driving on irregularities. The dynamic stability coefficient is proposed for use as an assessmentcriterion. The application of the developed method allows to obtain an assessment of stability in real time during theoperation of transport means.The structural scheme has been developed to ensure the reliability of the operation of wheeled vehicle, based onreducing the influence of the driver's qualifications as an element of the "driver-vehicle-road conditions" system on itsposition stability, taking into account the results of monitoring the technical condition.To conduct experiments and evaluate the results, the mobile registration and measurement complex (MRMC) wasused to assess and improve the safety of exploitation of wheeled vehicles, taking into account modern means andapproaches. A single-board computer Raspberry Pi version 3B + serves as a platform for the mobile registration andmeasurement complex. The architecture of MRMC is modular; it supports the installation of additional inertial sensors,photo and video fixation devices, GPS, as well as devices compatible with USB. Operating system – Raspbian based onDebian distribution (GNU / Linux).To further automate the process of controlling a wheeled vehicle, the promising scheme for the operation of theregistration and measuring complex with elements of artificial intelligence was developed, which allows, without theparticipation of the driver, to carry out the necessary actions to control it and ensure, including operational safety.The results can be used to assess the suitability and performance of wheeled vehicles.

A NEW WAY TO CONTROL THE DISTRIBUTION OF BRAKING FORCES BETWEEN THE AXLES OF THE CAR

The distribution of braking forces between the axles has a significant impact on the stability of the car when braking. Over the years, dozens of authors have proposed various methods for regulating braking forces and devices for their implementation (brake force regulators - RTS). The regulation process in most of the known technical solutions was carried out by changing the ratio of the pressure of the working fluid (liquid or air) in the actuators of the brake drive of the front and rear brakes. To change the ratio of the specified pressure, the regulation of the working fluid was used, which led to the instability of the regulation characteristics and the failure of the brake system. In this article, a new method for controlling the distribution of braking forces between the axles is proposed and researched, the essence of which is to change the ratio of the total areas of the actuators of the brake drives (the areas of the pistons of the working brake cylinders). The implementation of this method of controlling the distribution of braking forces between the axles became possible due to the creation of open-type multi-piston disc brakes with two pairs of concentrically arranged brake pads. The proposed method makes it possible to increase the stability of the car not only during emergency, but also during service braking. The aim of the study is to increase the stability of the car during emergency and service braking by using a new method of controlling the distribution of braking forces between the axles by discretely changing the size of the active working areas of the working brake cylinders. To achieve this goal, the tasks of determining the value of the coefficient of distribution of the brake force on the front axle of the car with a different combination of the included working brake cylinders on the wheels and rear wheels and determining the threshold values of the car deceleration, at which it is necessary to change the ratio of the included working brake cylinders on the wheels of the front and rear axles, are solved .The results of the study showed that the use of multi-piston disc brakes on the front and rear wheels of a twoaxle vehicle makes it possible to organize the process of impulse control of the distribution of braking forces between the axles.

The programmable steering machine for the electric lightweight vehicle

In this paper a programmable steering machine (PSM) and the lightweight electric powered vehicle, designed and made at the Kazimierz Pulaski University of Technology and Humanities in Radom (UTH Radom) have been presented. Both these technical objects are the result of the project carried out by the Student Research Group ?Turbodoładowani?. The steering machine has been developed with the programmable algorithms allowing to execute a controllable movement of the vehicle steering wheel. After execution, the system does not need an interaction with the driver. For this reason, a higher repetition of the vehicle traction measurements can be achieved. Such confirmation obtained in tests within which the time waveforms of rotation angle of the steering wheel by a set value of 45, 90, 180 and 360 degrees was recorded. In particular, the accuracy index for mentioned test conditions was calculated. Obtained results, expressed by the average value of the sensitivity index were lower than 2% within the tests carried out for ?45 degree maneuvers. In case of other tests i.e., for ?90, ?180 and ?360 degree maneuvers the accuracy index value was lower than 0.3%. In this way, it was confirmed that the tested PSM reached the appropriate operating parameters necessary for vehicle traction tests.

Wheel wear prediction for high speed railway vehicles during acceleration

Wheel wear prediction for high-speed railway vehicles during the acceleration process is of great importance for the improvement of operating characteristics and the development of friction management strategy near the railway station, especially in complex climatic environments. This work analyzes and predicts the wheel wear evolution of high-speed motor cars during acceleration. Firstly, detailed dynamic models of the high-speed motor car are developed, in which a comprehensive gear transmission system is also adopted to capture the accurate dynamic responses of the motor car. Secondly, the length of the simulated track interval with different friction coefficients is set according to the Gaussian distribution function to consider the influence of the friction coefficient. Moreover, a Proportional-Integral(PI) creep controller is also introduced to meet the challenge due to varying wheel-rail contact conditions, and a wheel wear prediction model based on the aforementioned submodels is established to obtain the wheel wear evolution. Finally, simulation results of dynamic responses from the vehicle dynamic model and wheel wear prediction procedure are compared with the measured field data. The results show that the time-varying meshing stiffness from the gear transmission system will aggravate the interaction between wheel and rail and deteriorate the wheel wear. When the high-speed motor car passes through a poor adhesion zone in the acceleration, it is easier to trigger the creep controller at the low-speed period while it will not occur at the high-speed period.

Salient features of wheel-vehicle aerodynamic interactions: Consequences for drag

Salient features of wheel–vehicle interactions and their consequences for drag are investigated experimentally based on a simplified square-back vehicle with different distances l between the rear wheels and the base of the vehicle. Two different mechanisms responsible for a base drag increase of up to 12% are distinguished. At the scale of the vehicle, whatever the distance l, wheels perturb the underflow and induce a global variation of the vertical balance of the vehicle wake. According to the state of the initial wake, significant base drag increase or decrease are observed. Considering the scale of the wheels, if the wheel-to-base distance l/w (w being the width of the wheels) is smaller than a threshold of order 3 in the present configuration, the base drag increases and is very sensitive to l/w. In this situation, a mean mass transfer from the vehicle wake to the wake of the rear wheels is observed. Based on these observations, a physical model is then proposed to explain this high-sensitivity regime.

Внутрішній контроль процедури оцінки вартості мобілізованих колісних транспортних засобів підприємства

The article identifies the issues related to compliance with the legislative requirements during the mobilization of wheeled vehicles for the benefit of the Armed Forces of Ukraine. The authors emphasize the need for ongoing monitoring of compliance with the mobilization procedure, and identifies its key areas and features, including the issues of documentation. The authors propose forms of working documents, that will allow documenting the procedures for controlling the mobilization of wheeled vehicles. The issue of conducting a proper assessment of the value of mobilized wheeled vehicles is separately highlighted. The article proves that the valuation of wheeled vehicles as of the date of its mobilization should be carried out at the liquidation value. This type of value, according to the legislation on valuation, should be interpreted as the cost of forced sale. The calculation of this valuation base should be based on the guidelines contained in clause 7.15 of the Order of the Ministry of Justice of Ukraine and the State Property Fund of Ukraine dated 24.11.2003 № 142/5/2092 «About Approval of the Methodology for Commodity Expertise and Valuation of Wheeled Vehicles» as amended, dated 24.05.2022 No. 2060/5/496.

Internal Control of the Procedure for Estimating the Cost of Mobilized Wheeled Vehicles of an Enterprise

Internal Control of the Procedure for Estimating the Cost of Mobilized Wheeled Vehicles of an Enterprise

Internal Control of the Procedure for Estimating the Cost of Mobilized Wheeled Vehicles of an Enterprise

Internal Control of the Procedure for Estimating the Cost of Mobilized Wheeled Vehicles of an Enterprise

Macrotexture deterioration for micromilled tunnel concrete pavement using 3D laser data

To ensure driving safety and cost effectively preserve pavements, unlike the traditional grooving, cutting joints, highway tunnels used micromilling resurfacing method to improve the skid resistance of concrete pavement. The sensor measured texture depth (SMTD) has been established for quantitatively evaluating micromilled surface quality. This paper explores the possibility of using three-dimensional line laser imaging technology to obtain the ‘full lane’ elevation data of the pavement, then through the calculation of the index SMTD, construct a road surface spatial and temporal deterioration model, and provide quality control covering the whole lane, and identify the problem areas. The results show that the road wear condition gradually worsens with the increase in opening time, after 24 months, the proportion of the good level (>0.55 mm) of the three cells is 70.5%, 75.1%, and 70.2%. Analysis of the test data for three cells revealed that the tunnel pavement shows canalization in wear. The most severely abraded section is offset by 200–300 mm toward the roadway median compared to the theoretical vehicle wheel track zone. Subsequent studies can expand the experimental conditions and consider more influencing factors to study further the texture deterioration of the micromilled pavement.

Prerequisites for the creation of domestic onboard diagnostics tools for the M1 and M2 categories vehicles

BACKGROUND: Due to the steady growth of the worldwide fleet of vehicles alongside the sophistication of their operational functions and the increase in the number and manufacturability of electronic control units, used in a vehicle, the demand for means of access to the performance of on-board electronic sys-tems at the final stages of their production and operation is increasing. This review is necessary to summarize the available data from the world experience in the development and implementation of on-board diagnostic systems.
 AIMS: Formulation of general principles for the development of onboard diagnostic systems, helpful to outline reasonable technical solutions for the task of creation of proprietary domestic diagnostic environment for vehicles.
 METHODS: This paper describes the purpose and role of onboard diagnostic systems used in world practice for modern vehicles. Classes of diagnostic devices are allocated according to the level of implemented functions. The grounds that determine the demand for development of proprietary onboard diagnostic systems for wheeled vehicles are considered. A review of the functionality of the original diagnostic tools of foreign vehicle manufacturers was carried out. The main requirements imposed on developers by the ISO 27145 and ISO 14229 group of standards within the framework of the implementation of modern diagnostic systems in domestic vehicles of the M1 and M2 categories are determined.
 RESULTS: A specific set of functions recommended for integration into diagnostic equipment being developed as a part of promising domestic developments has been determined. The content of the positive effect of the practical implementation of the measures proposed according to the results of the analysis is formulated.
 CONCLUSIONS: The performed scientific analysis of the features of the existing diagnostic equipment is helpful to determine the relevant trends in the implementation of a fundamentally new trend in on-board diagnostics in the Russian Federation, which contributes to increasing the level of competence of domestic specialists and development within the framework of the domestic engineering development strategy.

The Influence of the Relative Motion Dynamics of the Wheeled Vehicle Sprung and Unsprung Part on the Motion Stability along Curved Road Sections

The research method of the influence of the main suspension parameters on the motion stability of a wheeled vehicle was developed on the basis of a flat model of the dynamics of its relative motion. The mathematical model is a system of two nonlinear differential equations of the second order. The basic parameters of transverse angular oscillations of the sprung and unsprung part, which determine the dynamics of relative motion, are described using the basic principles of the perturbation method in combination with Ateb-functions. Kinetostatic equations and conditions of motion stability in the aggregate made it possible to determine the critical value of the steady motion speed as a function of the main parameters that characterize the suspension and the oscillations amplitudes of the sprung and unsprung part.It was established that an increase in the oscillations amplitude of the unsprung part from 0.01 rad to 0.015 rad causes a decrease in the critical speed of steady motion by up to 35%.The main results can serve as a basis for the suspension modernization of wheeled vehicle, and their reliability is confirmed by obtaining, in the extreme case, known results concerning suspensions with linear characteristics of elastic elements and damping devices

Automatic Parking Path Planning of Tracked Vehicle Based on Improved A* and DWA Algorithms

Compared to wheeled vehicles, tracked vehicles have unique advantages in disaster relief and engineering sites. The working environment of tracked vehicles is mostly in fixed-point conditions, so high-precision automatic stopping is essential for tracked vehicles. Improved A* and dynamic window approach are proposed in this article to enhance the accuracy and speed of automatic parking of tracked vehicles. The parking trajectory is significantly optimized within low deviations. Furthermore, a prototype is designed to verify the working conditions of fixed-point parking to improve the work efficiency of engineering rescue. The simulation results based on the robot operating system show that both single- and two-step parking methods can reach the parking position without collision. More importantly, simulated and experimental parking positions and angles have considerable accuracy within acceptable limits. This study has essential guidance and application value for the high-precision automatic parking of tracked vehicles for various extreme application scenarios.

Wheel-INS2: Multiple MEMS IMU-Based Dead Reckoning System With Different Configurations for Wheeled Robots

A reliable self-contained navigation system is essential for autonomous vehicles. Based on our previous study on Wheel-INS <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> , a wheel-mounted inertial measurement unit (Wheel-IMU)-based dead reckoning (DR) system, in this paper, we propose a multiple IMUs-based DR solution for the wheeled robots. The IMUs are mounted at different places on the wheeled vehicles to acquire various dynamic information. In particular, at least one IMU has to be mounted at the wheel to measure the wheel velocity and take advantage of the rotation modulation. The system is implemented through a distributed extended Kalman filter structure where each subsystem (corresponding to each IMU) retains and updates its own states separately. The relative position constraints between the multiple IMUs are exploited to further limit the error drift and improve the system’s robustness. Particularly, we present the DR systems using dual Wheel-IMUs, one Wheel-IMU plus one vehicle body-mounted IMU (Body-IMU), and dual Wheel-IMUs plus one Body-IMU as examples for analysis and comparison. Field tests illustrate that the proposed multi-IMU DR system outperforms the single Wheel-INS in terms of both positioning and heading accuracy. By comparing with the centralized filter, the proposed distributed filter shows unimportant accuracy degradation while holding significant computation efficiency. Moreover, among the three multi-IMU configurations, the one Body-IMU plus one Wheel-IMU design obtains the minimum drift rate. The position drift rates of the three configurations are 0.82% (dual Wheel-IMUs), 0.69% (one Body-IMU plus one Wheel-IMU), and 0.73% (dual Wheel-IMUs plus one Body-IMU), respectively.

On the Dynamics of Some Systems with Impacts and One-Way Constraints

The article considers some problems of mechanics about the rolling of a wheel with impacts and one-way constraints under dry friction. Such tasks are often encountered in practice when a vehicle wheel collides with or leaves an obstacle. The contact of the wheel with the road is assumed to be point, the dry friction model is the classical Euler-Coulomb model. A complete analysis of various cases of impact and post-impact movements of the wheel is given.

ESTIMATING THE MARKET VALUE OF A VEHICLE UNDER LIMITED INFORMATION

The article reveals the issues of estimating the market value of wheeled vehicles in conditions of limited information. If there is a shortage of data on the assessment base, it is necessary to take into account the differences between the base and the assessment objects. The authors assessed the market value of a special purpose vehicle (excavator). The estimation made it possible to obtain a generalized scheme of vehicle evaluation in conditions of limited data, which consists of five stages: market analysis, collection of market information, screening of anomalous objects, sampling of homogeneous vehicles, price adjustments. The assessment shows approaches to making price adjustments to the base models (including the time factor and the availability of taxes). The statistical method of price adjustments is used. The authors emphasize the need to distinguish between sales prices and supply prices of vehicles.

Simulation of the Joint Movement of a Robotic-Towing Vehicle and an Aircraft Using Signals from an Optocoupler Matrix

Actuality. The heavy workload of airports with transport and cargo aviation creates a problem the land logistics, that seriously complicates the work of the airfield towing system and personnel working processes. That entails expences associated with delayed deliveries or equipment downtime. The usage of the automatic aircraft movement systems, which are capable of towing aircraft round the clock and quickly along the airfield, following the optimal trajectory allows to avoid such situations.Purpose of research. Creation of the mathematical model and the control algorithm for the autonomous joint movement of a wheeled aircraft towing vehicle and an aircraft, where the control is based on the signals of an optocoupler array.Methods. Achieving this goal required solving the following problems: describing of a dynamic model of wheeled bodies interconnected by an elastic element; creation of a feedback model based on a group of optocouplers detecting a contrast line; description of the logical conditions that allow determining the position of the object relative to the contrast line. To describe the dynamics of the wheeled platform, the equations of Lagrangian dynamics, as well as the numerical methods of mathematical modeling, were used. An optocoupler array is considered as a tool for estimating the position of the system relative to the contrast line.Results. A mathematical model, which explores the system movement and reveals the interaction of the system elements has been developed. An adaptive algorithm based on the discrete type feedback for the system managing is developed. An example of the control system when moving in a straight line with the passage of turns at an angle of 90 degrees is considered. A combined braking system in which the distributed brake efforts both on a aircraft and the tower are formed is proposed.Conclusion. As a result of the mathematical modeling, it was found that the system of wheeled bodies, bound by the force of elasticity, is able to perform controlled movements along a straight line and when passing sharp turns, based on the readings of the optocoupler matrix; corresponding graphs are shown.