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Upcoming regulations from CARB and EPA will require diesel engine manufacturers to validate aftertreatment durability with full useful life aged components. To this end, the Diesel Aftertreatment Accelerated Aging Cycle (DAAAC) protocol was developed to accelerate aftertreatment aging by accounting for hydrothermal aging, sulfur, and oil poisoning deterioration mechanisms. Two aftertreatment systems aged with the DAAAC protocol, one on an engine and the other on a burner system, were directly compared to a reference system that was aged to full useful life using conventional service accumulation. After on-engine emission testing of the fully aged components, DOC and SCR catalyst samples were extracted from the aftertreatment systems to compare the elemental distribution of contaminants between systems. In addition, benchtop reactor testing was conducted to measure differences in catalyst performance.

Sensor selection for the control of modern powertrains is a recognised technical challenge. The key question is which set of sensors is best suited for an effective control strategy? This paper addresses the question through probabilistic modelling and Bayesian analysis. By quantifying uncertainties in the model, the propagation of sensor information throughout the model can be observed. The specific example is an abstract model of the slip behaviour of Selective Catalytic Reduction (SCR) DeNOx aftertreatment systems. Due to the ambiguity of the sensor reading, linearization-based approaches including the Extended Kalman Filter, or the Unscented Kalman Filter are not successful in resolving this problem. The stochastic literature suggests approximating these nonlinear distributions using methods such as Markov Chain Monte Carlo (MCMC), which is able in principle to resolve bimodal or multimodal results.

Modern control strategies for internal combustion engines use increasingly complex networks of sensors and actuators to measure different physical parameters. Often indirect measurements and estimation of variables, based off sensor data, are used in the closed loop control of the engine and its subsystems. Thus, sensor fusion techniques and virtual instrumentation have become more significant to the control strategy. With the large volumes of data produced by the increasing number of sensors, the analysis of sensor networks has become more important. Understanding the value of the information they contain and how well it is extracted through uncertainty quantification will also become essential to the development of control architecture. This paper proposes a methodology to quantify how valuable a sensor is relative to the architecture. By modelling the sensor network as a Bayesian network, Bayesian analysis and control metrics were used to assess the value of the sensor.

A new total fatigue life methodology was utilized to make fatigue life predictions, where total fatigue life is defined as crack initiation and subsequent crack propagation to a crack of known size or the component’s inability to carry load. Fatigue life predictions of an A36 steel T-joint geometry were calculated using the same total fatigue life methodology for both welded and machined test specimens that have the same geometry. The only significant difference between the two analyses was the inclusion of the measured weld residual stresses in the welded specimen life predictions. Constant amplitude tests at several load levels and R ratios were analyzed along with block cycle and variable amplitude loading tests. The accuracy of the life predictions relative to experimental test lives was excellent, with most within a factor of +/- two.

Internal combustion (IC) engines that meet Tier 4 Final emissions standards comprise of multiple engine operation and control parameters that are essential to achieve the low levels of NOx and soot emissions. Given the numerous degrees of freedom and the tight cost/time constraints related to the test bench, application of virtual engineering to IC engine development and emissions reduction programmes is increasingly gaining interest. In particular, system level simulations that account for multiple cycle simulations, incylinder turbulence, and chemical kinetics enable the analysis of combustion characteristics and emissions, i.e. beyond the conventional scope of focusing on engine performance only. Such a physico-chemical model can then be used to develop Electronic Control Unit in order to optimise the powertrain control strategy and/or the engine design parameters.

Many off-highway machines, including hydraulic excavators, perform cyclical motion in their everyday activities where there is significant acceleration, deceleration, load lifting and hydraulic implement lowering. During that time in conventional off-highway machinery, most of the potential or kinetic energy is dissipated as heat instead of being captured and reused. When these opportunities are well understood and consequently machine systems are designed and integrated properly, fuel efficiency improvements could reach double digit values. It should be noted that the mentioned machine efficiency improvements will still vary depending on the machine size, its application and the characteristics of machine system(s) being applied. An approach for excavator energy flow analysis, coupled with rapid machine control design changes directed to minimization of energy losses is discussed.

It is an engineering requirement that gases entrained in the coolant flow of an engine must be removed to retain cooling performance, while retaining a volume of gas in the header tank for thermal expansion and pressure control. The main gases present are air from filling the system, exhaust emissions from leakage across the head gasket, and also coolant vapour. These gases reduce the performance of the coolant pump and lower the heat transfer coefficient of the fluid. This is due to the reduction in the mass fraction of liquid coolant and the change in fluid turbulence. The aim of the research work contained within this paper was to analyse an existing phase separator using CFD and physical testing to assist in the design of an efficient phase separator.

Driven by the desire to implement low-cost, high-efficiency NOx aftertreatment systems, such as Three Way Catalysts (TWC) or Lean NOx Traps (LNT), a novel 6-Stroke engine cycle was explored to determine the feasibility of implementing such a cycle on a compression ignition engine while continuing to deliver fuel efficiency. Fundamental questions regarding the abilities and trade-offs of a 6-stroke engine cycle were investigated for near-stoichiometric and lean operation. Experiments were performed on a single-cylinder 15-liter (equivalent) research engine equipped with flexible valvetrain and fuel injection systems to allow direct comparison between 4-stroke and 6-stroke performance across multiple hardware configurations. 1-D engine simulations with predictive combustion models were used to support, iterate on, and explore the 6-stroke operation in conjunction with the experiments.

The characterization of fuel injector orifices is important for engine performance engineers, combustion engineers, and as input into 3-D spray and combustion simulations. Typical steady flow measurements done by fuel injector manufacturers are not indicative of their flow at engine injection pressures. Orifice characterization is commonly done on a rate bench or for further detail by using momentum rate measurements. The common Bernoulli equation assumptions made for momentum rate measurements are not always proper. This work compares the common approach with a more detailed approach for calculating the nozzle flow coefficients and sac pressure. The detailed approach includes friction and contraction pressure losses. A discussion on sac velocity is included. A non-iterative calculation of the Darcy friction factor is reviewed and an uncertainty analysis is also provided.

Selective Catalytic Reduction (SCR) is a leading aftertreatment technology for the removal of nitrogen oxide (NOx) from exhaust gases (DeNOx). It presents an interesting control challenge, especially at high conversion, because both reagents (NOx and ammonia) are toxic, and therefore an excess of either is highly undesirable. Numerous system layouts and control methods have been developed for SCR systems, driven by the need to meet future emission standards. This paper summarizes the current state-of-the-art control methods for the SCR aftertreatment systems, and provides a structured and comprehensive overview of the research on SCR control. The existing control techniques fall into three main categories: traditional SCR control methods, model-based SCR control methods, and advanced SCR control methods. For each category, the basic control technique is defined. Further techniques in the same category are then explained and appreciated for their relative advantages and disadvantages.

This paper uses a one-dimensional (1-D) simulation based approach to compare the steady state and transient performance of a Split Cycle Clean Combustion (SCCC) diesel engine to a similarly sized conventional diesel engine. Caterpillar Inc's one-dimensional modeling tool “Dynasty” is used to convert the simulation model of Caterpillar's current production turbocharged diesel engine Cat® C4.4 (used in their Hydraulic Excavator 316) to operate on the SCCC cycle. Steady state and transient engine performance is compared between the two engine variants. This study is focused only on the performance aspects of engine and relies on the other independently published papers for emissions prediction. This paper also demonstrates the use of Caterpillar's proprietary modeling software Dynasty to replicate the two cylinder SCCC engine model presented by University of Pisa in their paper [2].

Since 1992, Caterpillar has invested millions of dollars to purchase CAD software, and spends nearly $2M per year keeping its engineers up-to-date, via instructor lead training (ILT), as new enhancements are introduced. Periodic upgrades to the software also require huge resource (people, costs) commitments for the planning and execution of the training requirements required for a large global workforce. This paper will examine gaps uncovered in the efficiency and effectiveness of the current training process, and the cultural change required as a result of switching from an instructor led environment to a completely web-based solution, which, once deployed, had promised to change the way Caterpillar approached training for the future. The proposed change promised to improve human resource capability by utilizing new technological capabilities, and resulted in improvements in organizational capabilities as well.

It is a time and cost consuming way to physically develop Hybrid Electric Vehicle (HEV) supervisor controller due to the increasing complexity of powertrain system. This study aims to investigate the HEV supervisor controller development process using dSPACE midsize Hardware in the Loop simulation system (HIL) for HEV powertrain control. The prototyping controller was developed on basis of MircoAutoBox II, and an HIL test bench was built on midsize HIL machine for the purpose of verification. The feasibility and capability of HIL were attested by the prototyping control strategy and fault modes simulation. The proposed approach was demonstrated its effectiveness and applicability to HEV supervisor controller development.

The use of a partial flow sampling system (PFSS) to measure nonroad steady-state diesel engine particulate matter (PM) emissions is a technique for certification approved by a number of regulatory agencies around the world including the US EPA. Recently, there have been proposals to change future nonroad tests to include testing over a nonroad transient cycle. PFSS units that can quantify PM over the transient cycle have also been discussed. The full flow constant volume sampling (CVS) technique has been the standard method for collecting PM under transient engine operation. It is expensive and requires large facilities as compared to a typical PFSS. Despite the need for a cheaper alternative to the CVS, there has been a concern regarding how well the PM measured using a PFSS compared to that measured by the CVS. In this study, three PFSS units, including AVL SPC, Horiba MDLT, and Sierra BG-2 were investigated in parallel with a full flow CVS.

The swivel-type hinge mount specified in SAE J180 has been the standard alternator mounting for many years. However, in the mid-1990's on-highway applications began to experience vibration related failures due to casting excitation. This led to the eventual development of a stationary “pad mount” system in combination with an automatic belt tensioner. This paper will review the system component life and benefits of pad mount, and proposes an industry mounting standard for further application usage.