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2019, Periodica Polytechnica Mechanical Engineering
The study is dedicated to increasing open pit trucks with electrical transmission maneuverability indices. The possibility of forced controllability usage of rear traction wheels of open pit truck with the electrical transmission, which enables them to carry out maneuvers with the usage of a forced additional turn is presented. For the first time, there has been worked out a mathematical model of the forced additional turn. It enables to determine a correlation of rotational speed ratio of rear traction wheels of starboard and port sides of the wheeled vehicle relative to a tire-to-surface friction coefficient. Firstly, the analytical dependences, which allow predicting the indices of open pit trucks maneuverability while using the forced additional turn are determined. The mathematical model adopted to appropriate truck's electric drive control algorithm can lead to trucks performance increasing by means of maneuvering time reducing.
IOP Conference Series: Materials Science and Engineering
Handling characteristics of any vehicle refer to its directional control and stability for given steering input. The vehicle parameters such as mass, mass moment of inertia and location of C.G. play a vital role and decide handling response of vehicle under different scenarios. Safe drive is ensured by vehicle's responses such as yaw rate, roll rate and vehicle lateral acceleration. This paper presents steady state and transient state simulation of XUV 500 model in accordance with ISO 4138 and ISO 3888 test standards using CarSim-Simulink Cosimulation. Influence of changes in above mentioned parameters on Vehicle response during both tests is investigated. Further, control of power train output using torque vectoring is implemented in both tests and its effect on vehicle response is evaluated. The results show that understeer tendency of the vehicle is reduced in steady state test (Constant radius test: ISO 4138). Critical vehicle responses of yaw rate, roll rate, lateral acceleration and path tracking showed improvement during the DLC manoeuvre (ISO 3888) hence, improving stability at higher lateral accelerations.
Eastern-European Journal of Enterprise Technologies, 2016
The main aim of this project is to design and develop electro-mechanical truck driving system having hydraulic piston cylinder suspension. The model has been designed on the measurement data of actual dump truck. It can be used as for any type of truck and whole system is design to achieve proper turning on the sharp corner of the roads and making it electrical as more economic. SolidWorks (CAD software) is used for appropriate design and development and ANSYS FEA for simulation of the design. The work described in this paper is based on the elimination on the cost of truck and increasing the turning efficiency by replacing the whole driving system of the vehicle with separate motor of each wheel.
Balkan Journal of Electrical and Computer Engineering, 2015
Nowadays, electric vehicles have become an important area because of air pollution, increasing use of renewable energy sources and being exhausted of oil fuels. In our country even the usage of electrical vehicles is not widespread nowadays, but also very popular and it is thought that it will increase. In this area, new studies and projects appear continuously Real systems are moving systems and it is difficult and expensive to evaluate by electrical vehicles; therefore an experiment mechanism has been created. In this study two fixed magnet synchronous hub motors have been used as wheels and the other one as load. In order to find the speed of the wheel, load value and coefficient of friction related to sliding, Burckhardt model has been used and the results obtained with different speed and road conditions have been presented here.
SN Applied Sciences, 2020
Autonomous vehicle is gaining popularity in the market worldwide. Most autonomous vehicle are based on electric vehicles since they are easy to control. The torque control of electric vehicles is precise and easy since electric motor torque can be manipulated by controlling the motor current. Furthermore, the load of the vehicle affects the motor torque of an electric vehicle. A higher vehicle load requires high motor torque to propel the vehicle. Often in autonomous vehicle, the vehicle parameters and stability measure are set within a limit based on standard vehicle settings. However, a vehicle loaded with extra mass on either side can offset these parameters affecting the efficiency of the controller. Thus, in this paper the effect of load on vehicle longitudinal and lateral forces is identified. A simulation model of a two rear in-wheel motored electric vehicle is developed. The model is used to analyze the effect of load on vehicle longitudinal and lateral forces. Based on the result, increasing the load on the side of direction of lateral motion increases the lateral force generated. The high lateral force causes the tires to approach the tire friction circle limit. This can affect the automated vehicle performance since the tires are in unstable region.
Zbìrnik naukovih pracʹ Deržavnogo unìversitetu ìnfrastrukturi ta tehnologìj, 2023
The analysis of scientific publications related to the guiding of wheelsets of railway rolling stock along the rail track has been carried out. It is stated that for a valid simulation of the guiding of wheelsets by a rail track, an accurate description of the contact forces of adhesion is necessary. It was found that the flange wheel-rail contact exists only in combination with the angle of attack and in the presence of a lateral cohesive force. A scheme of power interaction of a wheelset with rails with a ridge contact of one of the wheels has been developed. The force contact interaction of a wheel and a rail is a process that is difficult to describe and, at the same time, very important for studying the dynamics of the frictional interaction of vehicles and track and the guiding of vehicles by the rail track. In the general case, the contact of the wheel with the rail occurs in two contact zones: on the rolling surface and on the flange. Simplified, the contact is considered as a two-point contact. The considered force factors cannot be unambiguously attributed to guiding factors or factors of resistance to movement. Specific values and guiding of forces and moments depend on the position of the wheelset relative to the rail track. It is argued that the longitudinal and transverse slips of the wheelsets cause resistance to movement and are overcome by guiding forces.
International Journal of Engineering Technologies and Management Research, 2020
Road security has become with time a topic of concern in our society as per the increasing number of accidents and deaths occurring on the highways. Regulatory experts on road users have constantly been working for ways to solve this problem and thence better the lives of the citizens. This paper is aimed at proposing a mathematical model integrating specific parameters, describing the dynamic lateral behavior of a vehicle's tire and chassis systems and enabling to state a relationship between road characteristics and vehicle dynamics. To achieve this, we made used of the fundamental theorems of dynamics for the modeling of the vehicle's suspended and non-suspended masses and load transfers, then we associated this with the Pacejka Tire model to obtain a complete vehicle model. After the particularization of a global model, a simulator was realized named "DYNAUTO SIMULATOR" which iterates the given variables to produce a consistent result. After an experimental research made on the Ndokoti-PK 24 road section we could, thanks to our simulator determine the maximum speed to have at every turn of this road section and also understand the effect of the modification of a vehicle's center of gravity on its stability. This work will be an important tool which can be recommended to the regulatory board as a major asset in the road construction policy and also in the improvement of road safety measures.
2012 IEEE/SICE International Symposium on System Integration (SII), 2012
This paper propose the tire force distribution method for a rear wheel drive electric vehicle. This method is developed to improve the vehicle stability under the high speed cornering condition and save the electric energy. To control the lateral vehicle motion, the desired yaw moment is calculated by yaw rate control using PID theory. And Total desired longitudinal force is also determined by acceleration pedal signal. The tire force distribution method calculates the desired longitudinal tire forces at left and right wheel using the desired yaw moment and total desired longitudinal force and Maximum longitudinal tire force. And Maximum longitudinal tire force is determined by tire friction circle theory. The proposed method is verified by the simulation using CarSim software. And it is found from simulation results that the proposed method provides improvement vehicle stability and saving the electric energy under the high speed cornering condition.
International Journal of Vehicle Systems Modelling and Testing, 2013
For off-road vehicle applications, the construction of drivetrain system has usually been largely dominated by the mobility requirements. With the growing demand to have a multipurpose on/off road vehicle with improved manoeuvrability over deformable soil, particularly at higher speed, the challenges opposing vehicle designers have become more complex. In addition to the conventional mechanical torque distribution devices, active torque distribution (ATD) systems utilise active differentials to control the drive torque independently distributed to each driving wheel and accordingly provide active control of traction and yaw moment. In this paper the multi-wheeled off-road vehicle performance and control is presented and different critical aspects are summarised and critically discussed.
Vehicle system dynamics, 2019
On the handling performance of a vehicle with different front-to-rear wheel torque distributions, Vehicle System Dynamics, ABSTRACT The handling characteristic is a classical topic of vehicle dynamics. Usually, vehicle handling is studied by analyzing the understeer coefficient in quasi-steady-state maneuvers. In this paper, experimental tests are performed on an electric vehicle with four independent motors, which is able to reproduce front-wheel-drive, rear-wheel-drive and all-wheel-drive (FWD, RWD and AWD, respectively) architectures. The handling characteristics of each architecture are inferred through classical and new concepts. The study presents a procedure to compute the longitudinal and lateral tire forces, which is based on a first estimate and a subsequent correction of the tire forces that guarantee the equilibrium. A yaw moment analysis is performed to identify the contributions of the longitudinal and lateral forces. The results show a good agreement between the classical and new formulations of the understeer coefficient, and allow to infer a relationship between the understeer coefficient and the yaw moment analysis. The handling characteristics vary with speed and front-to-rear wheel torque distribution. An apparently surprising result arises at low speed: the RWD architecture is the most understeering configuration. This is discussed by analyzing the yaw moment caused by the longitudinal forces of the front tires, which is significant for high values of lateral acceleration and steering angle. ARTICLE HISTORY
The process of delivery of indivisible goods is carried out by special transport. These units are a two-link road train and consist of a tractor and semitrailer (the total length of the road train is more than 35 m). Typically, the power and coupling properties of the tractor are not enough to meet the requirements for crosscountry ability, so the semi-trailer is equipped with an additional power plant and 4-8 pairs of active wheels. Conventional two-link road trains combine the positive qualities of two vehicles at once-a towing vehicle and a trailer. If these vehicles are all-wheel drive, then these vehicles turn into articulated road trains with all driving (active) wheels and doubled payload, capable of delivering off-road bulky indivisible goods.
The 30th SIAR International Congress of Automotive and Transport Engineering, 2019
The stability performances are very important to appreciate the vehicle ability to be driven in different conditions. Starting for a simple planar model of one axle, the motion equations characterizing the rollover or skidding possibility are obtained. These are interpreted as different concerns for the driver, vehicle design engineer or road design engineer. The influence over the vehicle stability is analyzed for different driving conditions as speed, grip coefficient, lateral slope of the ground, position of the vehicle center of gravity, braking or traction intensity, suspension characteristics. Based on the axles stability characteristics, some conclusion were drawn about the steering behavior of the full vehicle. Also, some recommendations for drivers are presented. The procedure presented here can also be used to establish some working algorithms for potential on-board safety systems able to prevent the stability loss.
IEEE Transactions on Vehicular Technology, 2001
International Research Journal of Engineering and Technology (IRJET), 2018
– From calculation 80% of the total vehicle can run on electricity upto 2030. This paper proposes a proper method for the certain calculation of the electrical vehicle transmission unit. Based on the vehicle desired performances, the electric motor power torque and output can be calculated. The liability of the mechanical parameters such as road load resistance, gear ratio, weight of the car, tractive efforts, wheel diameter, motor gearbox coupling efficiency and many more plays a very decisive role in the calculation consideration of electrical vehicle
International Journal of Mechanical Engineering Education, 2003
Many textbooks on mechanics for engineering students and engineers consider the concepts of rolling resistance and axle friction separately, expecting readers to combine the given analysis for each of them in determining, for instance, the magnitude of the force needed to move a railroad car. However, this requires a thorough free-body diagram analysis and, since examples are not typically included in the textbooks, students may have difficulty solving such problems. This study represents the solution of the problem in terms of both the dry axle friction and the rolling resistance. It is also suggested as a good synthesis problem that may be considered in teaching the effect of dry friction to engineering students.
International Research Journal of Modernization in Engineering Technology and Science, 2020
Automobile segment makes new transformations day by day to make Automobiles improved, comfortable, secure & safe. This paper distinct one of the major innovative idea which is 4WS (4Wheel-Maneuvering System). In this time every Automobile is mostly using a 2-wheeled to manage maneuverability movement of the Automobile. Automobiles have to move through Small and slippery roads. Which is the major problem for the Automobile and drivers of the vehicle. i.e. slipping of tires & unsafe cornering. However, the risk of accidents is increases. But the desire output of the 2Wheel management the required is low compared to compared to the 4W Maneuvering systems commonly used Automobiles. This is employed to advance and smoothen the response in some Automobiles to improve maneuverability response, increase Automobile balance while moving at average speeds, to reduce turning radius at low speeds. The 4W maneuvering system is a great technology to take a part in an automotive design engineer to provide a smooth and better reception to the driver. In a regularly steered Automobile, only front wheels are capable of balanced cornering but in 4W Maneuvering both front and rear wheels will turn in opposite directions for cornering by this one can confidently can say that 4W Maneuvering will be helpful & safe for cornering. Also, the 4WS (4Wheel-Maneuvering System) will not only be helpful in cornering but in performing various Automobile parking actions, driving in strenuous conditions with heavy traffic in congested areas. It is difficult because of Automobile's larger wheelbase and track width. The 4WS will help in less turning radius. Commercial Automobiles will be more helpful in this Maneuvering system. Even so, this type of maneuvering system can be used in future Automobiles.
IAEME, 2019
The lateral force acting on the tires produces a side slip angle that affects the directional stability of vehicle. This paper presents some research results of the influence of driving axle location on the lateral force of vehicle with 4x2 wheel formula when vehicle is turning. The single track dynamical models of FWD and RWD vehicle while cornering are created. Based on these two dynamical models, the system equations of motion built are enable to study the influence of driving axle location on the lateral force. Some calculated simulation results are shown for illustration.
The front-to-rear wheel torque distribution influences vehicle handling and, ultimately, affects key factors such as vehicle safety and performance. At a glance, as part of the available tire-road friction is used for traction on the driven axle, a Front-Wheel-Drive (FWD) vehicle would be expected to be more understeering than a Rear-Wheel-Drive (RWD) vehicle with equivalent characteristics. However, in specific conditions such effect may be counterbalanced, or even reversed, by the yaw moment caused by the lateral contribution, in the vehicle reference system, of the traction forces at the front wheels. This paper discusses the experimental assessment of the phenomenon in steady-state cornering, for a fully electric vehicle with multiple motors, allowing different front-to-rear wheel torque distributions. The results confirm that the yaw moment effect of the front traction forces is significant, especially at low vehicle speeds and high lateral accelerations. In particular, in the case study maneuvers, the RWD configuration of the vehicle resulted more understeering than the FWD one at the speed of 30 km/h.
Przegląd Elektrotechniczny, 2012
The principle of the electric vehicle is very simple: instead of an internal combustion engine with fuel stored in a tank and whose power is transmitted to the wheels through a gearbox, electric vehicle (EV) is powered by a traction system consisting of a central or two-wheel drive supplied by batteries, whose speed is controlled by an electronic control device. The propulsion system considered in this work is two driving wheels. It consists of two permanent magnet DC motors (PMDCM) directly coupled to the rear wheels of the vehicle forming a motor-wheel (driving wheel). Each motor-wheel is supplied by a static converter which is powered by batteries. The two sub systems (source-converter-motor) are coupled to an electronic differential in order to compensate the tendencies of direction of the vehicle and maintain a steady speed by adjusting the difference in speed of each motor-wheel according to the direction in the case of a turn.
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