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2015-09-29
Technical Paper
2015-01-2721
Balaji Lomada, R. Jayaganthan, V. Vijaykumar
Abstract Commercial vehicle industry is presently striving towards development of buses with enhanced passenger safety and comfort. This calls for additional components and aggregates that eventually lead to increase in the overall length and gross vehicle weight (GVW) of the bus for the same passenger capacity. Usually, steering system of longer front overhang (FOH) vehicles have multiple linkages such as bevel box arrangement or intermediate pivot arm arrangement instead of single direct draglink because of packaging and design constraints. In this work, an attempt has been made to design the steering system for one of the longer FOH bus with single direct draglink arrangement. Here, single draglink was packaged and designed with commercially available higher strength tube material. Design optimisation of steering geometry was carried such that the steering performance was atleast on par with existing performance.
2015-09-29
Technical Paper
2015-01-2734
Anand Deshpande, Himanshu Gambhir, Kshitiz Raj, Satish Kumar
Abstract Low steering effort is the basic requisite to proffer driver with drive comfort and easy maneuverability on turns. Various components in steering and suspension system play a vital role in determining the steering effort of vehicle. The discussion has been emphasized on static steering effort i.e. when vehicle is stationary and wheels are turned from lock to lock position. There are various factors which affect the steering effort of a vehicle. Following are the high priority factors: 1 Steering Geometry.2 Tyre static friction torque.3 Friction among the steering linkages. In this paper, the crucial factors which lead to difference in steering effort of RH and LH turn have been discussed in detail.
2015-09-29
Technical Paper
2015-01-2733
Samraj Benedicts, Vivek Seshan
Track tensioning assembly is used in tracked vehicles to maintain the tautness of the track. The track tensioning system consists of the rear idler wheel which applies pressure on the track and a mechanism to increase or decrease the tension. This paper is a study of reaction forces and its effects on the chassis due to rear idler position. Rubber track layouts have been focus for most of the research work, here we study the effect of rear idler position on chassis structure through simulated analysis. An agriculture paddy combine harvester with rubber track is considered for the purpose of this work. Firstly the complete chassis structure is modeled in 3D using Creo and exported to Pro Mechanica for simulation. The real time forces, constraints were applied and the results were correlated to actual field results. The simulations were optimized through several iterations to match the field test results.
2015-09-29
Technical Paper
2015-01-2732
Andrei Keller, Sergei Aliukov
Abstract The main indicators for mobility of a multipurpose wheeled vehicle are the maximum and average technical velocity, and they are mainly determined by power-to-weight ratio and the parameters of the suspension. As our analysis shows, with the increase of the power-to-weight ratio of the vehicle and its weight, the growth rate of the velocity is reduced, and after reaching a certain value, the velocity remains almost constant. This is due to the fact that for operating conditions of the multi-purpose wheeled vehicle, movement on roads with different degrees of uneven distribution of the rolling resistance and adhesion, in both transverse and longitudinal directions, is typical. In this investigation we evaluate the effectiveness of the main methods of power distribution among drive wheels of the multi-purpose wheeled vehicles.
2015-09-29
Technical Paper
2015-01-2749
Yang Chen, Mehdi Ahmadian, Andrew Peterson
Abstract This study provides a simulation evaluation of the effect of maintaining balanced airflow, both statically and dynamically, in heavy truck air suspensions on vehicle roll stability. The model includes a multi-domain evaluation of the truck multi-body dynamics combined with detailed pneumatic dynamics of drive-axle air suspensions. The analysis is performed based on a detailed model of the suspension's pneumatics, from the main reservoir to the airsprings, of a new generation of air suspensions with two leveling valves and air hoses and fittings that are intended to increase the dynamic bandwidth of the pneumatic suspensions. The suspension pneumatics are designed such that they are able to better respond to body motion in real time. Specifically, this study aims to better understand the airflow dynamics and how they couple with the vehicle dynamics.
2015-09-29
Technical Paper
2015-01-2748
Salem A. Haggag
Abstract The vehicle dynamics and controls play a significant role in vehicle handling performance characteristics. The control of vehicle braking system and wheel slip is a challenging problem due to the nonlinear dynamics of the braking process and the wheel-road interaction. A simple and at the same time realistic vehicle longitudinal braking model is essential for such a challenging problem. In this paper, a new longitudinal rolling/braking quarter-vehicle model is presented. The proposed model takes both the rolling resistance force and the braking force into consideration and investigates their impact on the vehicle longitudinal dynamics. An anti-lock sliding-mode controller is designed to provide wheel slip control during vehicle motion. This type of controller is chosen due to its expected robustness against varying road friction coefficient.
2015-09-29
Technical Paper
2015-01-2746
Bin Li, Subhash Rakheja
Abstract Vehicle jackknifing is generally associated with the loss of yaw stability, and is one of the most common cause of serious traffic accidents involving tractor-semitrailer combinations. In this paper, an active braking control strategy is proposed for jackknifing prevention of a tractor-semitrailer combination on a low friction road. The proposed control strategy is realized via upper-level and lower-level control structures considering braking of both the units. In the upper-level control, the required corrective yaw moments for tractor and semitrailer are generated using a PID controller aiming to reduce errors between the actual yaw rates of tractor-semitrailer and the target yaw rates deduced from a reference model. The corrective yaw moments are achieved through brake torque distribution among the tractor and semitrailer axle wheels in the lower-level control.
2015-09-29
Technical Paper
2015-01-2742
Linlin Wang, Hongyu Zheng, Changfu Zong, Yuchao Chen
Abstract Aiming at estimating the vehicle mass and the position of center of gravity, an on-line two-stage estimator, based on the recursive least square method, is proposed for buses in this paper. Accurate information of the center of gravity position is crucial to vehicle control, especially for buses whose center of gravity position can be varied substantially because of the payload onboard. Considering that the buses start and stop frequently, the first stage of the estimator determines the bus total mass during acceleration, and the second stage utilizes the recursive least-square methods to estimate the position of the center of gravity during braking. The proposed estimator can be validated by the co-simulation with MATLAB/Simulink and TruckSim software, simulation results exhibit good convergence and stability, so the center of gravity position can be estimated through the proposed method in a certain accuracy range.
2015-09-29
Technical Paper
2015-01-2740
Yuming Yin, Subhash Rakheja, Jue Yang, P. E. Boileau
Abstract The articulated frame steering (AFS) systems are widely implemented in construction, forestry and mining vehicles to achieve enhanced maneuverability and traction performances. The kinematic and dynamic performances of articulated steered vehicles are strongly influenced by properties of the frame steering system. In this paper, a flow volume regulated frame steering system is described and analytically modelled. The analytical model of the steering system is formulated in conjunction with yaw-plane model of a 35 tonnes mining vehicle to investigate steady as well as transient responses of the steering system and the vehicle. A field test program was undertaken to measure responses of the steering system and the vehicle under nearly constant speed turning as well as path-change maneuvers.
2015-09-29
Technical Paper
2015-01-2741
Yunbo Hou, Mehdi Ahmadian
Abstract This paper presents the results of a study on the effect of truck configurations on the roll stability of commercial trucks in roundabouts that are commonly used in urban settings with increasing frequency. The special geometric layout of roundabouts can increase the risk of rollover in high-CG vehicles, even at low speeds. Relatively few in-depth studies have been conducted on rollover stability of commercial trucks in roundabouts. This study uses a commercially available software, TruckSim®, to perform simulations on four truck configurations, including a single-unit truck, a WB-67 semi-truck, the combination of a tractor with double 28-ft trailers, and the combination of a tractor with double 40-ft trailers. A single-lane and multilane roundabout are modeled, both with a truck apron. Three travel movements through the roundabouts are considered, including right turn, through-movement, and left turn.
2015-09-29
Technical Paper
2015-01-2760
Andrei Izmailov, Vladimir Shevtsov, Alexandr Lavrov, Zahid Godzhaev, Vladimir Pryadkin
Maximum pressure is an essential parameter determining the degree of environmental impact of pneumatic tractor wheels on soils. The authors of the paper offer a method for determining and adjusting maximum pressure of a pneumatic tractor wheels on the supporting surface. The paper contains an analysis of the variation of maximum pressure on soils for various values of internal tire pressure and vertical load on a wheel. The above method allows parameters for systems of monitoring and adjustment of maximum pressure on soils to be set up by measuring tire flexure and adjusting it through changing the internal air pressure.
2015-09-29
Technical Paper
2015-01-2762
Chunshan Li, Pan Song, Guoying Chen, Changfu Zong, Wenchao Liu
Abstract This paper presents an integrated chassis controller with multiple hierarchical layers for 4WID/4WIS electric vehicle. The proposed systematic design consists of the following four parts: 1) a reference model is in the driver control layer, which maps the relationship between the driver's inputs and the desired vehicle motion. 2) a sliding mode controller is in the vehicle motion control layer, whose objective is to keep the vehicle following the desired motion commands generated in the driver control layer. 3) By considering the tire adhesive limits, a tire force allocator is in the control allocation layer, which optimally distributes the generalized forces/moments to the four wheels so as to minimize the tire workloads during normal driving. 4) an actuator controller is in the executive layer, which calculates the driving torques of the in-wheel motors and steering angles of the four wheels in order to finally achieve the distributed tire forces.
2015-09-29
Technical Paper
2015-01-2761
Boris Belousov, Tatiana I. Ksenevich, Sergei Naumov, Vitalii Stepnov, Anna Klimachkova
An electro-hydraulic servo system makes the basis for a mechatronic locomotion module (LM) and for a complex comprising an LM and an undercarriage of a vehicle. The servo system of the wheel module/LM complex is a combination of the information and power channels of the electro-hydraulic wheel drive within the steering system. A combination of the servo systems makes up a complex of servo systems of the steering system of the multi axis wheel mover of the vehicle. Theoretical and experimental studies of the functioning all-wheel steering were aimed on substantiation the rational algorithmic maintenance of the automatic control system. The results of the study allowed formulating the basic principles of designing and calculating the functionality algorithms for the steering system of the complex of mechatronic modules of the multi-axis vehicle.
2015-09-29
Technical Paper
2015-01-2763
S. F. Rahaman, Somenath Chatterjee
Abstract Steering pull during high speed braking of heavy commercial vehicles possesses a potential danger to the occupants. Even with negligible wheel-to-wheel brake torque variation, steering pull during the high speed braking has been observed. If the steering pull (i.e. steering rotation) is forcibly held at zero degree during high speed braking, the phenomena called axle twist, wheel turn and shock absorber deflection arise. In this work the data have been collected on the mentioned measures with an intention to develop a mathematical model which uses real time data, coming from feedback mechanism to predict the values of the measures in coming moments in order to aid steering system to ‘auto-correct’. Driven by the intention, ‘Time Series Analysis’, a well-known statistical methodology, has been explored to see how suitable it is in building the kind of model.
2015-09-29
Technical Paper
2015-01-2750
Tan Huang, Guoying Chen, Changfu Zong, Tong Zhou
Abstract Electronically controlled air suspension (ECAS) systems have been widely used in commercial vehicles to improve the ride comfort and handling stability of vehicles, as it can adjust vehicle height according to the driving conditions and the driver's intent. In this paper, the vehicle height adjustment process of ECAS system is studied. A mathematical model of vehicle height adjustment is derived by combining vehicle dynamics theory and thermodynamics theory of variable mass system. Reasons lead to the problems of “over-charging”, “over-discharging” and oscillation during the process of height adjustment are analyzed. In order to solve these problems, a single neuron proportional-integral-derivative (PID) controller is proposed to realize the accurate control of vehicle height. By simulation and semi-physical rig test, the effectiveness and performance of the proposed control algorithm are verified.
2015-09-29
Technical Paper
2015-01-2753
Xiujian Yang, Ruocheng Zhu, Jin Gao
Abstract Tractor semi-trailer as a widely-used heavy duty freight vehicle has caused many fatal accidents every year and one of the main factors of which may relate to its relatively poor lateral dynamics performance compared to the passenger cars [1, 2, 3]. In this paper, attention is concentrated on the parametric design for a tractor semi-trailer by optimizing the configuration parameters aiming to comprehensively improve the lateral dynamics performance. According to the previous public reports, the performance measures such as Load Transfer Ratio (LTR), Static Rollover Threshold (SRT), Rearward Amplification Ratio (RAR) and Ratio of Yaw Rate (RYR) are very effective measures and often be used to evaluate the handling and stability performances for tractor-trailer vehicles. However, each of those measures only pays attention to a certain aspect of vehicle lateral dynamics which is closely related to vehicle configuration parameters.
2015-09-29
Technical Paper
2015-01-2756
Basaran Ozmen, Mehmet Bakir, Murat Siktas, Serter Atamer, Roman Teutsch
Abstract Securing the desired strength and durability characteristics of suspension components is one of the most important topics in the development of commercial vehicles because these components undergo multiaxial variable amplitude loading. Leaf springs are essential for the suspension systems of trucks and they are considered as security relevant components in the product development phase. In order to guide the engineers in the design and testing department, a simulation method is developed as explained by Bakir et al. in a recently published SAE paper [1]. The main aim of the present study is to illustrate the validation of this simulation method for the durability of leaf springs based on the results from testing and measurements. In order to verify this CAE Method, the calculated stresses on the leaf springs are compared with the results of strain gage measurements and the fatigue failures of leaf springs are correlated with the calculated damage values.
2015-09-29
Technical Paper
2015-01-2801
Yuandong Liu, Gangfeng Tan, Xuexun Guo, Li Zhou, Wenbin Liu, Zhiqiang Hu, Kangping Ji, Binyu Mei
Abstract The hydraulic retarder, an important auxiliary brake, has been widely used in heavy vehicles. Under the non-braking working condition, the air resistance torque in the working chamber, which is formed by the rotor of hydraulic retarder's stirring the air, causes pumping loss. This research designs a new type of hydraulic retarder, whose helium is charged into working chamber through closed loop gas system under non-braking working condition, can reduce the parasitic power loss of transmission system. First, under non-braking working condition, the resistance characteristics are analyzed on the base of hydraulic retarder pumping model; then, considering some parameters, such as the volume of chambers and the initial gas pressure, the working chamber gas charge model is established, and the transient gas charge characteristics are also analyzed under non-braking working condition.
2015-09-29
Technical Paper
2015-01-2823
Uriy Usinin, Sergey Gladyshev, Maxim Grigoryev, Alexander Shishkov, Evgeny Belousov, A. M. Zhuravlev, Anton Bychkov, Dmitry Sychev
Abstract In this paper, we consider the hybrid power train for transportation of long pipes with big diameter. It is includes diesel engine for main towing vehicle and auxiliary electric drive for the active trailer The trains with active trailers are necessary at the building of oil and natural gas pipelines in no road conditions and marshlands. Due to the electric drive, the trailer's off-road capability on marshland conditions is sharply increased and its control is facilitated. The specified attractive qualities are appeared, if wheels of the trailer are executed as drivable, and the kinematic circuit of a drive is fulfilled as one-stage. At this, it is taken in attention that power of the electric drive will take 20 - 25 % from rated power of the basic traction drive, with the expanded range of torque control (till 1:10 and more). Such overloads are provided by the electric drive with synchronous reluctance machine of independent excitation developed by authors.
2015-09-29
Technical Paper
2015-01-2835
Sughosh J. Rao, Mohamed Kamel Salaani, Devin Elsasser, Frank Barickman, Joshua L. Every, Dennis A. Guenther
Abstract This study was performed to showcase the possible applications of the Hardware-in-the-loop (HIL) simulation environment developed by the National Highway Traffic Safety Administration (NHTSA), to test heavy truck crash avoidance safety systems. In this study, the HIL simulation environment was used to recreate a simulation of an actual accident scenario involving a single tractor semi-trailer combination. The scenario was then simulated with and without an antilock brake system (ABS) and electronic stability control (ESC) system to investigate the crash avoidance potential afforded by the tractor equipped with the safety systems. The crash scenario was interpreted as a path-following problem, and three possible driver intended paths were developed from the accident scene data.
2015-09-29
Technical Paper
2015-01-2833
Ashley L. Dunn, Brian Boggess, Nicholas Eiselstein, Michael Dorohoff, Harold Ralston
Abstract Brake chamber construction allows for a finite stroke for pushrods during brake application. As such, the Federal Motor Carrier Safety Regulations (FMCSRs) mandate maximum allowable strokes for the various chamber types and sizing. Brake strokes are often measured during compliance inspections and post-accident investigations in order to assess vehicle braking performance and/or capability. A number of studies have been performed, and their results published, regarding the effect of brake stroke and function on braking force and heavy truck stopping performance [1] through [4]. All of the studies have relied on a brake supply pressure of 100 pounds per square inch (psi). When brake strokes are measured in the field, following the Commercial Vehicle Safety Alliance (CVSA) procedure, the application pressure is prescribed to be maintained between 90 and 100 psi.
2015-09-29
Technical Paper
2015-01-2901
Shaoyun Sun, Genghua Liao, Qiang Fu, Kelong Lu, Jing Zhao, Zhengzheng Li, Jiaquan Chen, Guang Shi, Sacha Jelic, Bo Li
Abstract Trucks can carry heavy load and when applying the brakes during for example a mountain downhill or for an abrupt stop, the brake temperatures can rise significantly. Elevated temperatures in the drum brake region can reduce the braking efficiency or can even cause the brake system to fail, catch fire or even break. It therefore needs to be designed such to be able to transfer the heat out of its system by convection, conduction and/or radiation. All three heat transfer modes play an important role since the drum brakes of trucks are not much exposed to external airflow, a significant difference from disk brakes of passenger cars analyzed in previous studies. This makes it a complex heat transfer problem which is not easy to understand. Numerical methods provide insight by visualization of the different heat transfer modes. Presented is a numerical method that simulates the transient heat transfer of a truck drum brake system cooldown at constant driving speed.
2015-09-29
Technical Paper
2015-01-2841
Hongyu Zheng, Shenao Ma
Abstract This paper establishes a brake pedal model for braking intention identification, using the structural features of electronic braking system and selecting the proper parameters. A three-dimensional model is built that the input parameters are pedal displacement and pedal displacement change rate, and the output parameter is braking intensity. The relationship between the driver braking operation and braking intention are designed. A hardware-in-the-loop test bench experiment has been taken under several skilled drivers to practice the established the brake pedal model with the operation data during the braking. Thus, it results a model indicating the braking intention by braking operation that means effectively improve the braking comfort and applies to the research of electronic braking system of commercial vehicle.
2015-09-29
Technical Paper
2015-01-2842
Hongyu Zheng, Jinghuan Hu, Shenao Ma
Abstract Heavy vehicles have the characteristics of with high center of gravity position, large weight and volume, wheelbase is too narrow relative to the body height and so on, so that they always prone to rollover. In response to the above heavy security problems of heavy vehicle in running process, this paper mainly analyzes roll stability and yaw stability mechanism of heavy vehicles and studies the influence of vehicle parameters on stability by establishing the vehicle dynamics model. At the same time, this paper focuses on heavy vehicles stability control methods based on simulation and differential braking technology. At last, verify the effect of heavy vehicle stability control by computer simulation. The results shows that self-developed stability control algorithm can control vehicle stability effectively, so that the heavy vehicles instability can be avoided, the vehicle driving safety and braking stability are improved.
2015-09-29
Technical Paper
2015-01-2839
Rangaraj Ramanan Durai, Ashok Thirupathi, Mohith Krishna Shetty, Dilip Joy Mampilly
In this paper Longitudinal Force Slip (LFS) controller will be designed for controlling the traction force in each wheel when Rock Crawl Scenario prevails for commercial vehicles working in Off-Road condition. During Rock Crawling the wheels can have more longitudinal slip than lateral slip. Slip is caused by relative movement of tires with the rock. PID controller (Longitudinal Force Controller) will be designed in order to stabilize the traction force on individual wheels. Individual Lateral and Longitudinal force will be calculated for each wheel from Tire modeling. Optimal longitudinal force will be determined based on fuzzy model with the help of determined Mue. The designed LFS controller which controls the individual traction force by applying active braking. Active braking on individual wheel will be realized with the hydraulic system associated with Vehicle Stability Control ECU (VSC - ECU). Optimal engine torque will be calculated based on driver pedal request.
2015-09-29
Technical Paper
2015-01-2872
Massimiliano Ruggeri, Andrea Cervesato, Carlo Ferraresi
Abstract Performance requests and machine automation, in conjunction with new regulations for commercial and heavy duty vehicles, represent a difficult challenge for machine design. Machine control systems complexity and functional safety regulation, are complex requirements to deal with in new machines design. The paper describes a steering system design, of a 6 wheeled agricultural front articulated self-propelled machine, that must comply with new regulations in terms of functional safety. The vehicle steering is driven by an electro-hydraulic system, totally controlled using electronics; the rear wheels are independently steered and controlled. This architecture requires a highly functional safety performance level. The safety analysis of the system lead to a required performance level whose compliance is a challenging task, due to the software quality required, and to the cost of a fully redundant hardware, on both electronics and hydraulics side.
2015-09-29
Technical Paper
2015-01-2728
Paul C. Cain
Abstract OEM benefit: Vehicle manufacturers desire continuous feedback in monitoring key safety related sub-assemblies. In this application, engineers are calculating the remaining brake pad life by continuously monitoring the current thickness of the brake pad friction material. This information is used in scheduling preventative maintenance activities and avoiding safety incidents. Unplanned machine down time and field repair expenses in earthmoving equipment are cost prohibitive. Today, this technology allows OEM's to have high confidence, continuous feedback on this critical vehicle safety feature, avoiding expensive, unplanned repairs and to improve field “up time” performance. Application challenge: to develop a reliable linear position sensor that is suitable for continuous monitoring of brake pad material thickness in a high pressure, high temperature, high vibration and contaminated environment typical of large construction (earthmoving) vehicles.
2015-09-29
Technical Paper
2015-01-2725
Amine Nhila, Daniel E. Williams
Abstract Today's hydraulic steering systems suffer from poor efficiency due to their use of throttling valves to build pressure inside the steering gear. In this work, we propose a novel way to build and control pressure by controlling the flow from the pump and without throttling. As a result, such a system will be more energy efficient. Moreover, the ability to control pressure inside a steering gear, and thus assistance torque, allows the steering system to become an active closed-loop system rather than a passive open-loop system. Specifically, by controlling pressure, one can closely control the hand wheel torque the operator feels. Consequently, the new pressure control concept has the potential to not only significantly improve the efficiency of steering systems, but also offers the numerous benefits of torque overlay without the use of an electric motor.
2015-09-29
Technical Paper
2015-01-2745
Florian Bauer, Jan Fleischhacker
Abstract A Hardware-in-the-Loop (HiL) system for Electronic Control Units (ECU) of electro-pneumatic brake systems is presented. The HiL system runs a real-time capable vehicle model comprising of both the vehicle dynamics and the electro-pneumatic brake system. The dynamic behaviour of the vehicle can be simulated either by a real-time multi-body vehicle model or by a simpler system dynamic (double-track) model. To assess the quality of the system dynamic vehicle model, it is compared to a multi-body vehicle model which was validated with comprehensive experimental results. Discrepancies can be seen for highly unsteady manoeuvres. Reasons for these discrepancies caused by the modelling topology of the system dynamic vehicle model are given. In order to simulate the electro-pneumatic brake system, a real-time model has been developed and validated. The different topologies of brake systems can be assembled from components and integrated into the vehicle model.
2015-09-29
Technical Paper
2015-01-2849
Hariharan Venkitachalam, Axel Schlosser, Johannes Richenhagen, Mirco Küpper, Thomas Tasky
Abstract Electrification is a key enabler to reduce emissions levels and noise in commercial vehicles. With electrification, Batteries are being used in commercial hybrid vehicles like city buses and trucks for kinetic energy recovery, boosting and electric driving. A battery management system monitors and controls multiple components of a battery system like cells, relays, sensors, actuators and high voltage loads to optimize the performance of a battery system. This paper deals with the development of modular control architecture for battery management systems in commercial vehicles. The key technical challenges for software development in commercial vehicles are growing complexity, rising number of functional requirements, safety, variant diversity, software quality requirements and reduced development costs. Software architecture is critical to handle some of these challenges early in the development process.
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