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Patents granted recently to Mr. Rode have changed the industry capability to adjust and verify wheel-end bearings on trucks. Until now it was believed1 that there was nothing available to confirm or verify the most desirable settings of preload on these bearings. The new, breakthrough invention is a tool and spindle-locking nut that permit quick and accurate wheel bearing adjustment by utilizing direct reading force measurement. Bearings can be set to either SAE recommended preloads or specific endplay settings. The author has been working on bearing adjustment methods for industrial applications for over forty years, and considers these inventions to be his most important breakthrough for solving this elusive bearing adjustment problem. Consistent wheel bearing preload adjustment was not possible before, even though it was widely known to achieve the best wheel performance as noted in SAE specification J2535 and re-affirmed in 2006 by the SAE Truck and Bus Wheel Subcommittee.

In this paper, we are interested in developing a robust tire-force estimator for heavy duty vehicles. We use a combined model of the articulated vehicle: a yaw plane model for the chassis motion and a vertical plane model for the axles. In the proposed method, we make use of the on-board available sensors to which low-cost sensors are added. In order to optimize the sensors configuration, a robust exact differentiator is used in order to obtain accelerations from the measured velocities. Once the differentiation is obtained, the model is inverted to determine the unknown input forces. The approach is validated by comparing the estimation results to those given by the software simulator prosper .

A complete system approach to power semiconductor analysis and selection is set forth in this paper. In order to address design overkill, a suitable power profile across the desired drive schedule is obtained through vehicle simulation in lieu of worse case operating conditions. The representative profile is then applied to detailed models of the inverter, power device, and power device thermal stack-up in order to predict worse case, silicon junction temperature rise. The simulation stream includes a closed silicon thermal loop that leads to more accurate power loss and junction temperature calculations. The models are combined and exercised in a single platform for ease of integration and fast simulation. Herein, the methods will be applied to a working example of an inverter for motor drives, and analytical results will be reviewed.

With the introduction of advanced digital road maps, which include information on the slope and curve radius of the highways, predictive control for standard and hybrid commercial vehicles, based on these maps, is about to be released by the vehicle manufacturers. For example, intelligent predictive cruise control has been announced for introduction in 2012 by Scania and Daimler. In addition, hybrid commercial city buses like MAN's Lion's City Hybrid have already been implemented. But the question remains about the type of vehicle suitable for the implementation of predictive intelligent concepts, due to the high investment cost compared to the sometimes relatively low operating cost savings.

Facing a competitive and globalized market and with increasingly demanding customers, companies must constantly seek the development of practices in the development of new products. One of the current practices is the adoption of modularity. In that sense, the objective of this paper is to conduct an analysis of this practice in a Brazilian company, which manufactures agricultural machinery. The applicability of modular design in current products is focused. Therefore, a case study approach has been chosen. First, a review of the scientific literature was conducted, followed by field research, for collecting data based on interviews with product engineers and technical documentation. The case study shows the applicability of the modular design concept in a combine header, by increasing the number of repeated components. The modular header approach facilitates the implementation of engineering changes and allows greater standardization of components.

To get a sequence retainable rainflow cycle counting algorithm for fatigue analysis, an alternate equivalent explanation to rainflow cycle counting is introduced, based on which an iterative rainflow counting algorithm is proposed. The algorithm decomposes any given load-time history with more than one crest into three sub-histories by two troughs; each sub-history with more than one crest is iteratively decomposed into three shorter sub-histories, till each sub-history obtained contains only one single or no crest. Every sub-history that contains a single crest corresponds to a local closed (full) cycle. The mean load and alternate load component of the local cycle are calculated in parallel with the iterative procedure.

This research was to model a 6×4 tractor-trailer rig using TruckSim and simulate severe braking maneuvers with hardware in the loop and software in the loop simulations. For the hardware in the loop simulation (HIL), the tractor model was integrated with a 4s4m anti-lock braking system (ABS) and straight line braking tests were conducted. In developing the model, over 100 vehicle parameters were acquired from a real production tractor and entered into TruckSim. For the HIL simulation, the hardware consisted of a 4s4m ABS braking system with six brake chambers, four modulators, a treadle and an electronic control unit (ECU). A dSPACE simulator was used as the “interface” between the TruckSim computer model and the hardware.

The main purpose of this research is to investigate the optimal design of pipeline diameter in an air brake system in order to reduce the response time for driving safety using DOE (Design of Experiment) method. To achieve this purpose, this paper presents the development and validation of a computer-aided analytical dynamic model of a pneumatic brake system in commercial vehicles. The brake system includes the subsystems for brake pedal, treadle valve, quick release valve, load sensing proportional valve and brake chamber, and the simulation models for individual components of the brake system are established within the multi-domain physical modeling software- AMESim based on the logic structure. An experimental test bench was set up by connecting each component with the nylon pipelines based on the actual layout of the 4×2 commercial vehicle air brake system.

Due to the diversity of Heavy Duty Vehicles (HDV), the European CO2 and fuel consumption monitoring methodology for HDVs will be based on a combination of component testing and vehicle simulation. In this context, one of the key input parameters that need to be accurately defined for achieving a representative and accurate fuel consumption simulation is the vehicle's aerodynamic drag. A highly repeatable, accurate and sensitive measurement methodology was needed, in order to capture small differences in the aerodynamic characteristics of different vehicle bodies. A measurement methodology is proposed which is based on constant speed measurements on a test track, the use of torque measurement systems and wind speed measurement. In order to support the development and evaluation of the proposed approach, a series of experiments were conducted on 2 different trucks, a Daimler 40 ton truck with a semi-trailer and a DAF 18 ton rigid truck.

Safety and minimal transit time are vital during transportation of essential commodities and passengers, especially in winter conditions. Icy roads are the worst driving conditions with the least available friction, leaving valuable cargo and precious human lives at stake. The study investigates the available friction at the tire-ice interface due to changes in key operational parameters. Experimental analysis of tractive performance of tires on ice was carried out indoor, using the terramechanics rig located at the Advanced Vehicle Dynamics Laboratory (AVDL) at Virginia Tech. The friction-slip ratio curves obtained from indoor testing were inputted into TruckSIM, defining tire behavior for various ice scenarios and then simulating performance of trucks on ice. The shortcomings of simulations in considering the effects of all the operational parameters result in differences between findings of indoor testing and truck performance simulations.

In this research paper, a novel train traction system is described. In this system, the vehicle is lifted like a hovercraft by air cushion and the traction is achieved by using horizontally mounted all-wheel drive. Chance of derailment is completely eliminated and wherein even in the event of failure of few traction wheel stations during run, the train remains mobile with absolute safety even at high speeds. All-wheel drive traction is powered by overhead electrification to maintain high power to weight ratio and faster acceleration. In the present invention, no rail is used. This eliminates the enormous cost of laying the complex and expensive railway tracks. Other advantages include the lack of exhaust fumes and carbon emissions at point of use especially in countries where electricity comes primarily from non-fossil sources, less noise, lower maintenance requirements of the traction units.

Road vibrations cause fatigue failures in vehicle components and systems. Therefore, reliable and accurate damage and life assessment is crucial to the durability and reliability performances of vehicles, especially at early design stages. However, durability and reliability assessment is difficult not only because of the unknown underlying damage mechanisms, such as crack initiation and crack growth, but also due to the large uncertainties introduced by many factors during operation. How to effectively and accurately assess the damage status and quantitatively measure the uncertainties in a damage evolution process is an important but still unsolved task in engineering probabilistic analysis. In this paper, a new procedure is developed to assess the durability and reliability performance, and characterize the uncertainties of damage evolution of components under constant amplitude loadings.

This paper describes the development and testing of a Dynamic Vibration Absorber to reduce frame beaming vibration in a highway tractor. Frame beaming occurs when the first vertical bending mode of the frame is excited by road or wheel-end inputs. It is primarily a problem for driver comfort. Up until now, few options were available to resolve this problem. The paper will review the phenomenon, design factors affecting a vehicle's sensitivity to frame beaming, and the principles of Dynamic Vibration Absorbers (AKA Tuned Mass Dampers). Finally, the paper will describe simulation and testing that led to the development of an effective vibration absorber as a field fix.

A range of axle suspensions, comprising hydro-pneumatic struts and diverse linkage configurations, have evolved in recent years for large size mining trucks to achieve improved ride and higher operating speeds. This paper presents a comprehensive analysis of different independent front suspension linkages that have been implemented in various off-road vehicles, including a composite linkage (CL), a candle (CA), a trailing arm (TA), and a double Wishbone (DW) suspension applied to a 190 tons mining truck. Four different suspension linkages are modeled in MapleSim platform to evaluate their kinematic properties. The relative kinematic properties of the suspensions are evaluated in terms of variations in the kingpin inclination, caster, camber, toe-in and horizontal wheel center displacements considering the motion of a hydro-pneumatic strut. The results revealed the CL and DW suspensions yield superior kinematic response characteristics compared to the CA and TA suspensions.

At present, the active safety and stability of heavy vehicles have becoming big concern among the road transportation industry. The purpose of this paper is to specify the research stability and safety of heavy vehicles those set up the accurate and reliable dynamic vehicle reference model and search the method to improve the stability and safety of tractor and semitrailer. A Multi-objective control algorithm was studied to differential braking based on linear quadratic regulator (LQR) control method. Simulation results show that the multi-objective control algorithm can effectively improve the vehicle driving stability and safety.

Braking energy recovery can significantly contribute to fuel economy and emission reduction, particularly for commercial vehicles driving in urban environment. By using the compressed air storage, rather than expensive and vulnerable batteries, this paper proposes a pneumatic hybrid system with an integrated compressor/expander unit (CEU) for commercial vehicles, in order to achieve stop/start function and braking energy recovery. During braking, the compressed air is recovered by CEU working in compressor mode and is charged to the air tanks. When the vehicle starts from stop, the CEU works as an expander to crank the engine with compressed air. The compressed air can also be used to supply the air tank of brake boost system, thus reducing its energy consumption. The mathematical models of energy conversion units, including the two modes of CEU and the air brake system, are established and analyzed.

The objective of this project was to compare the fuel consumption and traction performances of 6 × 2 and 6 × 4 Class 8 tractors. Two approaches have been considered: evaluation of 6 × 2 tractors, modified from 6 × 4 tractors, and evaluation of OEM 6 × 2 tractors. Compared to the 6 × 4 tractors, which are equipped with a rear tandem with both drive axles, the 6 × 2 tractors have a rear tandem axle with one drive axle, and one non-drive axle, also called dead axle. The 6 × 2 tractor configurations are available from the majority of Class 8 tractor manufacturers. The SAE Fuel Consumption Test Procedures Type II (J1321) and Type III (J1526) were used for fuel consumption track test evaluations. Traction performances were assessed using pull sled tests to compare pulling distance, maximum speed, and acceleration when pulling the same set sled on similar surface.

This paper focuses on the manufacturer's conflict in the conceptual design of commercial vehicles between highly customized special vehicles and the greatest possible degree of standardization. Modularity and standardization are crucial success factors for realizing high variance at the best cost efficiency in development and production as well for achieving the highest quality standards at reduced efforts for technical validation. The presented virtual design approach for commercial vehicle concepts allows for purposeful design and integration of new concepts and technologies on the component level in an existing product portfolio - not neglecting manufacture's portfolio requirements concerning standardization and modularity. The integrated tool chain helps to bring trade-offs to a head that exist in balancing between dedicated vehicles with best customer-relevant characteristics and standardized vehicles with the highest degree of commonality.

The ride comfort of the commercial vehicle is mainly affected by several vibration isolation systems such as the primary suspension system, engine mounting system and the cab mounting system. A rigid-flexible coupling model for the truck was built and analyzed in multi-body environment (ADAMS). The method applying the excitation on the wheels center and the engine mountings in time domain was presented. The variables' effects on the ride performance were studied by design of experiment (DOE). The optimal design was obtained by the co-simulation of the ADAMS/View, iSIGHT and Matlab. It was found that the vertical root mean square (RMS) acceleration and frequency-weighted RMS acceleration on the seat track were reduced about 17% and 11% respectively at different speeds relative to baseline according to ISO 2631-1.

The suspension system of a heavy truck's driver seat plays an important role to reduce the vibrations transmitted to the seat occupant from the cab floor. Air-spring is widely used in the seat suspension system, for the reason that its spring rate is variable and it can make the seat suspension system keep constant ‘tuned’ frequency compared to the conventional coil spring. In this paper, vibration differential equation of air-spring system with auxiliary volume is derived, according to the theory of thermodynamic, hydrodynamics. The deformation-load static characteristic curves of air-spring is obtained, by using a numerical solution method. Then, the ADAMS model of the heavy truck's driver seat suspension system is built up, based on the structure of the seat and parameters of the air-spring and the shock-absorber. At last, the model is validated by comparing the simulation results and the test results, considering the seat acceleration PSD and RMS value.