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This paper discusses controller development for an active, off-road vehicle suspension system. A brief review of electronic filters and their characteristics is used to provide insight on the difficulties of designing a control algorithm for negotiating hilly and rough terrain at higher speeds. Two controller designs are presented. One was designed by pole placement and causes the suspension response to approximate a Type 1 Chebychev filter. The other was designed using constrained optimization. A comparison and discussion of simulation results leads to the conclusion that the suspension should be adaptively or predictively controlled for arbitrary terrain and velocity conditions.

Collision warning systems (CWS) are a relatively new technology to reduce or mitigate motor vehicle rear-end and side impact collisions. This study compared available police-reported crash experiences of 6,143 CWS-equipped heavy trucks with the experiences of 383,058 heavy trucks without CWS. Data were from the Motor Carrier Management Information System (2000-2002). Results suggest that CWS-equipped trucks had a significantly lower proportion of crashes involving other moving vehicles and a significantly lower proportion of multiple vehicle crashes compared to trucks without CWS, (40% vs. 49%, p<0.0001; 62% vs. 67%, p<0.004 respectively). These changes are the first crash-data based evidence that supports the design effect of CWS. However, more studies are needed to determine the specific impacts of CWS on heavy truck crashes.

This paper focus on some of the fatigue methodologies based on the frequency domain and how they can be used on the heavy vehicle industry. A calculation flow was developed which consist of two steps. At first the stresses on the desired frequency bandwidth are calculated using a finite element software and those are then used as inputs on a Matlab script that estimate the expected life using two different theories, Bendat’s narrow band and Dirlik. The proposed methodology is then compared with more established time domain calculations. At first a plain hand calculation with a simpler input is performed on both domains before evaluating the differences with a more complex random stress signal input. Finally, test data from a rig test is used to validate the frequency domain fatigue methods using real life data.

Comparison studies have been conducted on a 1:16th scale model and a full scale tractor trailer of a variety of sealed aft cavity devices as a means to develop or enhance commercial drag reduction technology for class 8 vehicles. Various base cavity geometries with pressure taps were created for the scale model. The studies confirmed that length has an important effect on performance. The interaction of the boat-tailed aft cavity with other drag reduction devices, specifically side skirts, was investigated with results showing no discernable drag performance interaction between them. Overall, the experiments show that a boat-tailed aft cavity can reduce the drag up to 13%. Full-scale tests of a commercially derived product based on these scale tests were also completed using SAE Type II testing procedures. Full-scale tests indicated a fuel savings of over 6.5%.

Currently, all heavy-duty on-road engines in the USA are certified for emissions compliance using the Federal Test Procedure (FTP) heavy-duty transient cycle. The engine in a hybrid drive system, on the other hand, is controlled at a more steady-state level to reduce emissions over conventional drive systems. In this study, Allison Electric Drive seeks a better standardized emissions test cycle to certify (in the near term) engines which will be used in parallel and series hybrid drive systems. Actual revenue service data from a transit hybrid electric vehicle (HEV) was compared to several standard engine test cycles including the US FTP, ISO 8178 (a collection of many steady-state cycles), the Euro III (ESC) 13-mode cycle, and the Japanese 13-mode cycle. Graphical analysis of actual hybrid engine data revealed that the ESC cycle reflects field data better than other cycles, including the US FTP, which has little correlation.

For several staged collisions, results obtained with closed form reconstruction calculations and with a computerized step-by-step procedure are compared with measured responses. A refined, closed-form reconstruction procedure is defined, derivations of the analytical relationships are outlined and detailed results of sample applications are presented. Closed form calculation procedures for estimating impact conditions became a topic of interest in relation to the development of an automatic starting routine for iterative applications of the Simulation Model of Automobile Collisions (SMAC) computer program. The accuracy of initial estimates of speeds determines the total number of iterative adjustments of SMAC that are required to achieve an acceptable overall match of the evidence. Since a high degree of success was achieved in the refinement of such calculation procedures, the end product, by itself, is considered to be a valuable aid to accident investigations.

Frequency domain testing has had limited use in the past for durability evaluations of automotive components. Recent advances and new perspectives now make it a viable option. Using frequency domain testing for components, test times can be greatly reduced, resulting in considerable savings of time, money, and resources. Quality can be built into the component, thus making real-time subsystem and full vehicle testing and development more meaningful. Time domain testing historically started with block cycle histogram tests. Improved capabilities of computers, controllers, math procedures, and algorithms have led to real time simulation in the laboratory. Real time simulation is a time domain technique for duplicating real world environments using computer controlled multi-axial load inputs. It contains all phase information as in the recorded proving ground data. However, normal equipment limitations prevent the operation at higher frequencies.

SAE RP J1096 and CSA Standard Z107.22 are compared in terms of their performance as predictors of pass-by sound levels measured in accordance with SAE RP J366b. The comparison is based on the results of tests on 60 diesel trucks covering a range of ages, sound levels and configurations. The CSA procedure is found to be at least as good a predictor of pass-by sound levels as RP J1096 and can be used on smaller and noisier sites. The results of some exploratory measurements of the effects of wind and temperature gradients on the repeatability of the two procedures are also presented and discussed.

Inerters have become a hot topic in recent years, especially in vehicle, train, and building suspension systems. The performance of a passive inerter and a semi-active inerter was analyzed and compared with each other and it showed that the semi-active inerter has much better performance than the passive inerter, especially with the Hybrid control method. Eight different layouts of suspensions were analyzed with a quarter car model in this paper. The adaptation of dimensionless parameters was considered for a semi-active suspension and the semi-active inerters. The performance of the semi-active inerter suspensions with different layouts was compared with a semi-active suspension with a conventional parallel spring-damper arrangement. It shows a semi-active suspension, with more simple configuration and lower cost, has similar or better compromise between ride and handling than a semi-active inerter with the Hybrid control.

This paper describes the results of a series of fatigue studies relating the lives of several weld geometries. Rotating beam and axially loaded specimens were used. A comparison between steel and plastic (polyvinylchloride scale models is made. Using plastic scale models of welded structures for fatigue life determination is the ultimate goal of this work.

In order to evaluate the THOR-50M as a front impact Anthropomorphic Test Device (ATD) for vehicle safety design, the ATD was compared to the H3-50M in matching vehicle crash tests for 20 unique vehicle models from 2 vehicle manufacturers. For the belted driver condition, a total of fifty-four crash tests were investigated in the 56.3 km/h (35 mph) front rigid barrier impact condition. Four more tests were compared for the unbelted driver and right front passenger at 40.2 km/h (25 mph) in the flat frontal and 30-degree right oblique rigid barrier impact conditions. The two ATDs were also evaluated for their ability to predict injury risk by comparing their fleet average injury risk to Crash Investigation Sampling System (CISS) accident data for similar conditions. The differences in seating position and their effect on ATD responses were also investigated.

Regulatory requirements in the European Union (EU) for off-road machines and road vehicles are different. Vehicles which transport passengers and goods, along with attached trailers, as well as road motorcycles must meet EEC type-approval requirements. All other types of self-propelled machines must meet the requirements of the Machinery Directive (Council Directive 98/37/EC), and the Electromagnetic Compatibility (EMC) Directive (Council Directive 89/336/EEC) and possibly other directives. This includes such categories as agriculture and forestry machines, construction machines, industrial trucks and similar products. The various directives outline the different processes for demonstrating compliance with the EU requirements. The intent of this paper is to summarize a few of the requirements that are of interest to off-highway equipment manufacturers and to identify some sources of information about the regulatory requirements.

On-board vehicle electronics have matured and become a practical replacement for the many menial tasks required of a tractor operator. Electronic control systems allow more application flexibility and enhance performance more than a human operator could ever be expected to accomplish. This paper covers the possibilities for a fully automated tractor that optimally controls engine speed, transmission gears, fuel consumption and attached implement. The paper is written around a Soviet built four wheel drive tractor. The system described has been built and tested with very positive results.

“Today, wearing parts are regularly subjected to abnormal loading conditions. They must be able to accept these conditions without failure. In continuous operations, unscheduled downtime greatly increases maintenance costs, not to mention the cost of lost production. White iron castings offer premium abrasion resistance for many of these applications, but are often not used due to the possibility of brittle failure and the difficulty of mechanical attachment. This paper discusses the properties and applications of a composite of martensitic white iron and mild steel. This laminate will accept medium to high impact without loss of service failure, and can be installed by mechanical means or with welded attachment.”

The paper describes a detailed mathematical analysis of the problem of jet mixing in swirling or transverse flow fields under non-isothermal, non-isodense conditions. The model takes into account potential core effects, cross sectional distortion and differences in profiles between the distributed properties (velocity, concentration, temperature and density). Comparisons with a wide range of experimental results have produced excellent agreement.

Euro 6 emission norms are getting implemented in India from April 2020 and it is being viewed as one of the greatest challenges ever faced by the Indian automotive industry. In order to achieve such stringent emission norms along with top performance for vehicle, a good strategy should be incorporated to control system out NOx emissions and soot regeneration. Extruded Vanadium catalyst is deployed for this passive regeneration system with DOC (Diesel Oxidation Catalyst), DPF (Diesel Particulate Filter) and SCR (Selective Catalyst Reduction), where the amount of catalyst loading in DOC plays an apex role in deciding conversion efficiency of SCR and passive regeneration capabilities. This study mainly focuses on the impact of catalyst loading of DOC over SCR efficiency. NO2 to NOx ratio should be close to 0.5 for optimum conversion efficiency of SCR. Catalyst loading in DOC decides the amount of NO2 coming upstream to SCR.

Euro 6 emission norms are getting implemented in India from April 2020 and it is being viewed as one of the greatest challenges ever faced by the Indian automotive industry. In order to achieve such stringent emission norms a good strategy will be to optimize the engine out emission through in cylinder emission control techniques and a right sized after treatment system has to be used for this optimized engine. There exist several factors and trade-off between these should be established for in cylinder optimization of emissions. Since the turbocharger plays an apex role in controlling both the performance and engine out emissions of a CI engine, turbocharger selection is a crucial step in the development of new generation of Euro 6 engines in India. Such engines are equipped with additional actuators such as Intake Throttle Valve and Exhaust Throttle Valve and combination of these flap operations with turbocharger output plays a prominent role in controlling performance and emission.

This paper describes the conversion of a stationary spark ignition engine to a heavy duty (HD) natural gas engine suitable for transportation applications, in response to the new urban truck and bus legislation of 1994 and 1998. The approach to the fuel and ignition control system is to use a microprocessor controlled engine management system based on inputs from combustion air and natural gas mass flow sensors. As the emission control system is also based on stoichiometric three way catalyst technology, it is felt that the control approach is very robust. The engine and control system were first mounted on a HD dynamometer for the development work where engine control parameters were calibrated. In addition steady state emission data were collected and estimates of the HD transient emission levels were obtained.

In order to improve the noise immunity of vortex flowmeters, we have investigated the hydrodynamic vibration around the bluff body of the flowmeter. We used numerical approaches to visualize the time dependent vortex motion within the channel of the flowmeter, and experimental approaches to clarify the characteristic of the hydrodynamic vibration on the side faces of the prismatic bluff body. The results show that the hydrodynamic vibrations with 180° phase shift occur on the side faces of the bluff body, i.e. the prism. The most intense vibration points are situated here. By using differential transducers, a vortex flowmeter with improved measurement accuracy has been developed.

Effects of included spray angle with different injection strategies on combustion characteristics, performance and amount of pollutant emission have been computationally investigated in a common rail heavy-duty DI diesel engine. The CFD model was firstly validated with experimental data achieved from a Caterpillar 3401 diesel engine for a conventional part load condition at 1600 rev/min. Three different included spray angles (α = 145°, 105°, 90°) were studied in comparison with the traditional spray injection angle (α = 125°). The results show that spray targeting is very effective for controlling the in-cylinder mixture distributions especially when it accompanied with various injection strategies. It was found that 105° spray cone angle along with an optimized split pre- and post-Top Dead Center (TDC) injection strategy could significantly reduce NOx and soot emissions without much penalty of the fuel consumption, as compared to the wide spray angle.