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Contemporary manufacturing systems are still evolving. The system elements, layouts, and integration methods are changing continuously, and ‘collaborative robots’ (CoBots) are now being considered as practical industrial solutions. CoBots, unlike traditional CoBots, are safe and flexible enough to work with humans. Although CoBots have the potential to become standard in production systems, there is no strong foundation for systems design and development. The focus of this research is to provide a foundation and four tier framework to facilitate the design, development and integration of CoBots. The framework consists of the system level, work-cell level, machine level, and worker level. Sixty-five percent of traditional robots are installed in the automobile industry and it takes 200 hours to program (and reprogram) them.

Misfiring or partial combustion during diesel engine operation results in the production of partial oxidation products such as ethylene (C₂H₄), carbon monoxide and aldehydes, in particular formaldehyde (HCHO). These compounds remain in the cylinder as residual gases to participate in the following engine cycle. Carbon monoxide and formaldehyde have been shown to exhibit a dual nature, retarding ignition in one temperature regime, yet decreasing ignition delay periods of hydrocarbon mixtures as temperatures exceed 1000°K. Largely unknown is the synergistic effects of such species. In this work, varying amounts of C₂H₄ and HCHO are added to the intake air of a naturally aspirated optical diesel engine and their combined effect on autoignition and subsequent combustion is examined. To observe the effect of these dopants on the low-temperature heat release (LTHR), ultraviolet chemiluminescent images are recorded using intensified CCD cameras.

This study evaluates the performance of an indirect injection (IDI) diesel engine fueled with cotton seed biodiesel while assessing the engine's multi-fuel capability. Millions of tons of cotton seeds are available in the south of the US every year and approximately 10% of oil contained in the seeds can be extracted and transesterified. An investigation of combustion, emissions, and efficiency was performed using mass ratios of 20-50% cotton seed biodiesel (CS20 and CS50) in ultra-low sulfur diesel #2 (ULSD#2). Each investigation was run at 2400 rpm with loads of 4.2 - 6.3 IMEP and compared to the reference fuel ULDS#2. The ignition delay ranged in a narrow interval of 0.8-0.97ms across the blends and the heat release rate showed comparable values and trends for all fuel blends. The maximum volume averaged cylinder temperature increased by approximately 100K with each increase in 1 bar IMEP load but the maximum remained constants across the blends.

The simulation of I.C. Engines operation, especially during transients, requires a fairly accurate estimation of the internal mechanical losses of the engine. The paper presents generic friction models for the main friction components of the engine (piston-ring-liner assembly, bearings and valve train), considering geometry of the engine parts and peculiarities of the corresponding lubrication processes. Separate models for the mechanical losses introduced by the injection system, oil and water pumps are also developed. All models are implemented as SIMULINK modules in a complex engine simulation code developed in SIMULINK and capable to simulate both steady state and transient operating conditions. Validation is achieved by comparison with measurements made on a four cylinder, common rail diesel engine, on a test bench capable to run controlled transients.

The piston secondary motion is an important phenomenon in internal combustion (IC) engine. It occurs due to the piston transverse and rotational motion during piston reciprocating motion. The piston secondary motion results in engine friction and engine noise. There has been lot of research activities going on in piston secondary motion using both analytical models and experimental studies. These studies are aimed at reducing the engine friction as well as the noise generated due to piston secondary motion. The aim of this paper is to compile the research actives carried out on the piston secondary motion and discuss the possible research opportunities for reducing the IC engine piston secondary motion.

The focus of this study is to determine the effect of using B-20 (a blend of 20% soybean methyl ester biodiesel and 80% ultra low sulfur diesel fuel) on the combustion process, performance and exhaust emissions in a High Speed Direct Injection (HSDI) diesel engine equipped with a common rail injection system. The engine was operated under simulated turbocharged conditions with 3-bar indicated mean effective pressure and 1500 rpm engine speed. The experiments covered a wide range of injection pressures and EGR rates. The rate of heat release trace has been analyzed in details to determine the effect of the properties of biodiesel on auto ignition and combustion processes and their impact on engine out emissions. The results and the conclusions are supported by a statistical analysis of data that provides a quantitative significance of the effects of the two fuels on engine out emissions.

The objective of this work is to develop a strategy to reduce the penalties in the diesel engine performance, fuel economy and HC and CO emissions, associated with the operation in the low temperature combustion regime. Experiments were conducted on a research high speed, single cylinder, 4-valve, small-bore direct injection diesel engine equipped with a common rail injection system under simulated turbocharged conditions, at IMEP = 3 bar and engine speed = 1500 rpm. EGR rates were varied over a wide range to cover engine operation from the conventional to the LTC regime, up to the misfiring point. The injection pressure was varied from 600 bar to 1200 bar. Injection timing was adjusted to cover three different LPPCs (Location of the Peak rate of heat release due to the Premixed Combustion fraction) at 10.5° aTDC, 5 aTDC and 2 aTDC. The swirl ratio was varied from 1.44 to 7.12. Four steps are taken to move from LTC to ALTC.

The variation of the crankshaft's speed is influenced by the action of the cylinders and shall reflect the contribution of each cylinder to the total engine output. At the same time, the speed variation is influenced by the torsional stiffness of the cranks, the mass moments of inertia of the reciprocating mechanisms and the average speed and load of the engine. As the result, the variation of angular motion of the crankshaft is complex, each particular influence changing its importance as speed and load are modified. The diagnostic method presented in the paper is based on the analysis of the amplitudes and phases of the lowest harmonic orders of the measured speed and is capable to determine the average Indicated Mean Effective Pressure (IMEP), to detect nonuniformities in cylinder operation and to identify the faulty cylinder(s).

Unburned hydrocarbon (UBHC) emissions from gasoline engines remain a primary engineering research and development concern due to stricter emission regulations. Gasoline engines produce more UBHC emissions during cold start and warm-up than during any other stage of operation, because of insufficient fuel-air mixing, particularly in view of the additional fuel enrichment used for early starting. Impingement of fuel droplets on the cylinder wall is a major source of UBHC and a concern for oil dilution. This paper describes an experimental study that was carried out to investigate the distribution and “footprint” of fuel droplets impinging on the cylinder wall during the intake stroke under engine starting conditions. Injectors having different targeting and atomization characteristics were used in a 4-Valve engine with optical access to the intake port and combustion chamber.

The non-uniform character of the torque produced by a reciprocating I.C. engine is reflected in the cyclic variation of the crankshaft's speed. Because the crankshaft is an elastic structure, its response to the different harmonic components of the torque is different and changes with engine speed. The lowest harmonic components of the engine torque do not excite torsional vibrations and correlate fairly well with the corresponding harmonic orders of the crankshaft's speed. Based on a random vector model of the harmonic components of the gas-pressure torque, a statistical correlation is obtained between amplitudes and phases of the same harmonic component of the gas-pressure torque and of the crankshaft's speed. The lowest major harmonic order determines the average IMEP of the engine and the half-order detects if a cylinder is a lesser contributor to the total engine output and identifies the deficient cylinder.

A dimensionless relationship that estimates the maximum bearing load of a 4-cylinder 4-stroke in-line engine has been found. This relationship may assist the design engineer in choosing a desired counterweight mass. It has been demonstrated that: 1) the average bearing load increases with engine speed and 2) the maximum bearing load initially decreases with engine speed, reaches a minimum, then increases quickly with engine speed. This minimum refers to a transition speed at which the contribution of the inertia force overcomes the contribution of the maximum pressure force to the maximum bearing load. The transition speed increases with an increase of counterweight mass and is a function of maximum cylinder pressure and the operating parameters of the engine.

Combustion instability is investigated during the cold starting of a single cylinder, direct injection, 4-stroke-cycle, air-cooled diesel engine. The experiments covered fuels of different properties at different ambient air temperatures and injection timings. The analysis showed that the pattern of misfiring (skipping) is not random but repeatable. The engine may skip once (8-stroke-cycle operation) or twice (12-stroke-cycle operation) or more times. The engine may shift from one mode of operation to another and finally run steadily on the 4-stroke cycle. All the fuels tested produced this type of operation at different degrees. The reasons for the combustion instability were analyzed and found to be related to speed, residual gas temperature and composition, accumulated fuel and ambient air temperature.

Recent legislation entitled “The Single Fuel Forward Policy” mandates that all vehicles deployed by the US military be operable with aviation fuel (JP-8). Therefore, the authors are conducting an investigation into the influence of JP-8 on a diesel engine's performance. The injection, combustion, and performance of JP-8, 20-50% by weight in ULSD (diesel no.2) mixtures (J20-J50) produced at room temperature, were investigated in a small indirect injection, high compression ratio (24.5), 77mm separate combustion chamber diesel engine. The effectiveness of JP8 for application in an auxiliary power unit (APU) at continuous operation (100% load) of 4.78bar bmep/2400rpm was investigated. The blends had an ignition delay of approximately 1.02ms that increased slightly in relation to the amount of JP-8 introduced. J50 and diesel no.2 exhibited similar characteristics of heat release, the premixed phase being combined with the diffusion combustion.

A new friction testing system has been designed and built to simulate the actual engine conditions in friction and wear test of piston-ring and cylinder liner assembly. Experimental data has been developed as Friction Coefficient / Crank Angle Degree diagrams including the effects of running speed (500 and 700 rpm) and ring normal load. Surface roughness profilocorder traces were obtained for tested samples. Mixed lubrication regime observed in the most part of the test range. New cylinder bore materials and lubricants can be screened easily and more reliable simulated engine friction data can be collected using this technique.

The increased interest for using alternative fuels in modern diesel engines requires better combustion control to achieve safe and efficient operation with fuels characterized by different physical and chemical properties. Knowing the ignition delay and the cylinder peak pressure will allow adapting the injection strategy, mainly injection timing to maintain good engine efficiency when operating with different alternative fuels. The use of the measured instantaneous crankshaft speed to estimate peak cylinder pressure and ignition delay is very attractive because speed is already a parameter in the ECU of the engine. Based on models using powertrain dynamics, the paper presents the development of several techniques using the measured speed to estimate the main combustion parameters for single cylinder and four cylinder diesel engines.

Late-injection low-temperature diesel combustion is found to further reduce NOx and soot simultaneously. The combustion phenomena and detail chemical kinetics are studied with high speed spray/combustion images and time-resolved spectroscopy analysis in a rapid compression machine (RCM) with a small bowl combustion chamber. High swirl and high EGR condition can be achieved in the RCM; variable injection pressure and injection timing is supplied by the high-pressure common-rail fuel injection system. Effect of small amount of premix hydrogen gas on diesel combustion is also studied in the RCM. A hydrogen injector is located in the upstream of air inlet for delivery small amount and premixed hydrogen gas into cylinder just before the compression stroke. The ignition delay is studied both from the pressure curves and the chemiluminescence images.

Wall-wetting due to liquid fuel film motion and fuel droplet impingement on combustion chamber walls is a major source of unburned hydrocarbons (UBHC), and is a concern for oil dilution in PFI engines. An experimental study was carried out to investigate the effects of injection timing, a charge motion control device, and the matching of injector with port geometry, on the “footprints” of liquid fuel inside the combustion chamber during the PFI engine starting process. Using a gasoline-soluble dye and filter paper deployed on the cylinder liner and piston top land surfaces to capture the liquid fuel footprints, the effects of the mixture formation processes on the wetted footprints can be qualitatively and quantitatively examined by comparing the wetted footprint locations and their color intensities. Real-time filming of the development of wetted footprints using a high-speed camera can also show the time history of the fuel wetting process inside an optically accessible engine.

A test program has been conducted to determine the fracture behavior of the human frontal bone against two different rigid cylindrical surfaces; one surface was of 1 in. radius and one was of 5/16 in. radius; both were 6½ in. long. The purpose of this research program was to provide human tolerance data which would: 1. Assist in the design of structures likely to be impacted by the human head. 2. Extend the calibration range of frangible headforms. Twelve cadavers were tested in this program; seven against the 1 in. radius cylinder and five against the 5/16 in. radius cylinder. The test arrangement employed a guided drop of the test surface against a stationary head which was free to rebound. Drop heights were increased progressively until borderline fractures were obtained. The large radius shape consistently yielded linear fractures indicating that it is effectively a blunt surface. Fracture loads ranged 950-1650 lb.

A review of the literature dealing with the injury tolerance of the lower extremities in quantitative terms is provided. The data stem from sources ranging from Weber (1859) to as recent as Culver (1984) and in all cases involve tests of embalmed or unembalmed cadaveric specimens. The strength of the femur (thigh bone) and tibia (shin bone) have been depicted primarily in terms of the peak axial compressive force or bending moment associated with fracture-producing tests. Peak forces involved in fracturing the patella (knee cap) are reported for static and dynamic distributed loads involving both padded and rigid contact surfaces. One study is described where patella data are available for punch-through type fractures resulting from loading by small diameter impactors. Limited data are provided for hip joint dislocation and/or pelvic fracture as a result of loading through the femur. Finally, limited data are also included for injury at the knee and ankle joints.

In this age of the Internet of Things, people expect in-vehicle interfaces to work just like a smartphone. Our understanding of the reality of in-vehicle interfaces is quite contrary to that. We review the fundamental principles and metrics for automotive visual-manual driver distraction guidelines. We note the rise in portable device usage in vehicles, and debunk the myth of increased crash risk when conversing on a wireless device. We advocate that portable electronic device makers such as Apple and Google should adopt driver distraction guidelines for application developers (whether for tethered or untethered device use in the vehicle). We present two design implications relevant to safe driving. First, the Rule of Platform Appropriateness: design with basic principles of ergonomics, and with driver's limited visual, manual and cognitive capacity, in mind. Second, the Rule of Simplicity: thoughtful reduction in the complexity of in-vehicle interfaces.