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Since its inception, beam forming has become one of the most popular techniques in the acoustics society. Today acoustics engineers use this measurement technique for sound pressure visualization, noise source identification at mid and high frequencies. With the plentiful possibilities, many acoustics professionals want to use this technique but it could be very costly and time consuming at times. The beam forming method complements near field acoustic holography method and can be used for mid to high frequencies (1000-10kHz). Since there are many ways to arrange the microphone positions in a sensor array, we introduced some reasoning and estimation as how to design an array with minimal sensors. In addition, in a stationary operating condition, the array could be rotated to gain more resolution and accuracy. In this paper, we described the regular fixed position array designs with circular 8, cross 8 and circular 9 sensor arrays.

Feedforward artificial neural networks are universal function approximators and inherently parallel computing structures. Because of the lack of appropriate hardware realisations, applications of neural networks are predominantly implemented as sequential programs on digital processors. In this paper we describe an analogue integrated circuit realisation of a local response neural network (LCNN) that achieves a high degree of parallel computation in a small size, low cost and low power consumption. Because it can directly receive analog inputs from sensors and output analog control signals to actuators it is well suited as a building block for real-time control systems.

This document presents a methodology for obtaining the vehicle performance curves and values by means of the OBD2 port for a specific vehicle. In particular the Torque - Power engine curves and acceleration performance following SAE guidelines. Additionally we obtain the wheel dynamic rolling radius to get a more realistic performance. The results obtained are compared to a chassis dynamometer test performed on the same vehicle to prove feasibility for a low cost implementation when there is no access to said testing tools.

The energy crisis coupled with depleting fuel reserves and rising emission levels has encouraged research in the fields of performance enhancement, emission reduction technologies and engineering designs. The present paper aims primarily to offset the problem of high emissions and low efficiencies in low cost CI engines used as temporary power solutions on a large scale. The investigation relates to the low cost optimization of an intake runner having the ability to vary the swirl ratio within the runner. Test runs reveal that NOx and CO2 follow a relatively smaller gradient of rise and fall in their values depending on the configuration; whereas UHC and CO have a rapid changes in values with larger gradients. However, in a relative analysis, no configuration was able to simultaneously reduce all emission parameters and thus, there exists a necessity to find an optimized configuration as a negotiation between the improved and deteriorated parameters.

Until recently, it was necessary to spend tens of thousands of dollars on hardware and software to produce computer generated accident reconstruction animations. Several software companies have now developed powerful 3-D animation for the PC, Mac, and Amiga machines. This paper compares several such systems and describes a method to produce animations using the PC-compatible platform.

Powertrain system duplication for hybrid electric vehicles and range-extenders presents serious cost challenges. Cost increase can be mitigated by reducing the number of cylinders but this usually has a negative impact on noise, vibration and harshness (NVH) of the vehicle system. This paper considers a novel form of two-stroke cycle engine offering potential for low emissions, reduced production cost and high potential vehicle efficiency. The engine uses segregated pump charging via the use of stepped pistons offering potential for low emissions. Installation as a power plant for automotive hybrid electric vehicles or as a range-extender for electric vehicles could present a low mass solution addressing the drive for vehicle fleet CO2 reduction. Operation on the two-stroke cycle enables NVH advantages over comparable four-stroke cycle units, however the durability of conventional crankcase scavenged engines can present significant challenges.

Electric driving is generally limited to short distances in an emission sensible urban environment. In the present situation with high cost electric storage and long charging duration hybridization is the key to enable electric driving. In comparison to the passenger car segment, where numerous manufacturers are already producing and offering different hybrid configurations for their premium class models, the two wheeler sector is not yet affected by this trend. The main reason for the retarded implementation of this new hybrid technology is its high system costs, as they cannot be covered by a reasonable product price. Especially for the two wheeler class L1e, with a maximum speed of 45 km/h and an engine displacement of less than 50 cm₃, the cost factor is highly important and decisive for its market acceptance, because the majority of vehicles are still low-cost products equipped with simple carbureted 2-stroke engines.

This paper reports the studies, design and developments of an electronic electro-actuated gearshifter installed on the DP7, which is Politecnico di Milano car that took part at Formula SAE 2015 competitions in Hockenheim and Varano dè Melegari. The original idea was born to replace the hydraulic gearshift system used until 2011 because of its high weight and cost. After many evaluations about the kind of technology to use, made by previous team members in the electronic department, the final project was a fully electric shifter. This system has proven its qualities among which are lightness and low cost.

This paper presents a low-cost switched diversity receiver system utilizing a single tuner, simple remote antenna unit and one RF cable. The switched diversity algorithm is implemented in the receiver using digital signal processing. The remote unit contains RF switches that select from multiple antenna elements in response to a control signal from the receiver. The control signal is sent from the receiver to the remote unit via the RF cable. Simple logic in the remote unit provides decoding for switch control.

In addition to supporting the full repertoire of bus controller functions required for the protocol portion of the R.T. Production Test Plan, the latest generation of low cost 1553 protocol testers provides versatile capabilities for remote terminal simulation and real-time monitoring. When used in conjunction with a very low cost “Noise” (Word Error Rate) tester, such a protocol tester is capable of performing the “Bus Switching” test for dual redundancy. This class of noise tester provides all the necessary hardware and firmware required to perform the Word Error Rate Test of the R.T. Validation (SEAFAC) test, including the noise source. Both instruments are fully controllable by means of the IEEE-488 (GPIB) interface, including DMA capability for the protocol tester.

Pressure sensors in automobiles are used in connexion with electronic systems intended to control carburation. The pressure range to be measured is around the atmospheric pressure, a tolerance in the order of ±2% is required in the temperature range from 0 to 80°C good reproducibility and reliability, especially as for low infant mortality, together with low prices are mandatory. A new type of pressure sensor aiming to fit the above mentioned characteristics has been developed taking advantage from the piezoresistive effect of thick-film resistors screened-and-fired on ceramic diaphragms. The device consists of a ceramic diagphram bound around the edge, where in proper positions four resistors electrically connected according to Weathstone bridge configuration are screened-and-fired. The deformation of the diaphragm because of an applied pressure causes bridge unbalancing and output signal proportional to the pressure itself.

Today some semiconductor chips can be replaced with software. The time of day implementation presented in this paper now costs only pennies instead of dollars more then a non clock radio. This is possible because the need for external clock chips has been eliminated in many applications. All of this and even more is possible with todays selection of CMOS microprocessors.

Increasing number of ECU's (Electronic Control Units) being used in modern vehicles have given rise to HIL (hardware in the loop) testing, and model based design approach to design/test ECU's even before the proto-type vehicle is ready. However, it is not uncommon to discover surprising system design lapses during actual vehicle operation reported after vehicle launch. Major cause behind such lapses are found to be the gap between actual field performance/robustness of various vehicle sub-systems interfaced with ECU's and those modeled as ideal cases during HIL testing in the lab. This creates a need to evolve effective vehicle-level validation strategies to expose such performance deficiencies of real life sub-systems provided by the vendors. This paper describes a new approach to validate ECU in real time.

This paper presents a zero dimensional thermodynamic model that predicts the pressure behavior in the combustion chamber of a small compression ignition monocylinder engine. In fact this is a virtual pressure sensor, very simple to be implemented on microcontroller. It cooperates with the electronic control unit to perform the engine management. The aim of this innovative system, just patented, is to act on the control injection strategy improving engine performance, reducing consumption, emissions and acoustic noise.

A recent advance in speech synthesis technology is the integration of a complete speech synthesizer onto a single integrated circuit. This chip is the basis for several low cost “talking” consumer products. Speech is synthesized from stored digital information extracted from actual speech signals. Memory requirements are approximately 1200 bits per second or 800 bits per word. This development offers the potential for including voice response into a wide variety of applications at a very low cost.

This study evaluates the performance of an ethanol fueled spark ignited engine running with high levels of hydration. Ethanol is a renewable fuel and has been considered a promising alternative to counteract global warming and to reduce pollutant emissions. Its use is well established in ICE as the main fuel or blended with gasoline. However, due to its lower calorific value, it shows increased fuel consumption when compared to gasoline, rendering its use sometimes less attractive. The energy demand to produce ethanol, especially at the distillation phase, increases exponentially as the concentration of ethanol-in-water goes from 80% onwards. Thus, mixtures with less than 80% of ethanol-in-water would reduce the energy consumption during production, yielding a less expensive fuel. In previous studies, to evaluate the feasibility of wet ethanol as a fuel for spark-ignited engines, results have shown that it was possible to use mixtures of up to 40% of water-in-ethanol.

The objective of this research was to determine the feasibility of applying strain based fatigue life calculation models, which are commonly used for metals, to smooth SRIM polymer matrix composite axial specimens subjected to variable amplitude loading. A thorough investigation of the monotonic and strain controlled constant amplitude low cycle fatigue behavior of this material was conducted, including the effects of mean strains/stresses on the fatigue life of smooth specimens. Using these results, mean stress life calculations were made on the constant amplitude tests, as well as on smooth specimens subjected to strain controlled variable amplitude loading, using the Morrow and SWT mean stress models. These results were compared to experimental data, and it was found that the correlation between experimental and calculated lives was very poor, for both the constant amplitude and variable amplitude tests.

In fast breeder reactors, materials such as 10Zr-15Si titanium modified austenitic stainless steel are utilised for the cladding and wrapping of the fuel. Using Al/Zn ratios of 8 and 12 and a constant carbon content of 0.05%, the temperature dependency of the improved alloy's low cycle fatigue life was studied throughout a temperature range of 433-764 K. This evaluation was carried out over the whole temperature range. Under both of these circumstances and at all temperatures, cyclic hardening was seen in the alloy. Based on the cyclic stress response and micro processes of deformation, three temperature regions in the range of 433-764 K have been discovered for the alloy with an Al/Zn ratio. These temperature domains are as follows: predynamic strain ageing regime, dynamic strain ageing regime, and regime with active precipitation processes. All of these temperature domains occur between 433 and 764 K.

The effect of Si-phase on the axial, low-cycle fatigue behavior of Al-Si eutectic alloys was investigated using test specimens prepared from alloys processed either by continuous casting or extrusion. Results indicate that, for continuous casting, all fatigue fractures resulted from shear-type crack initiation and propagation with an attendant shortening of fatigue life. For extruded material, fatigue cracks originated in the Si phase. In both instances, initiation and growth mechanisms were essentially identical to those observed in high-cycle fatigue. Cyclic properties obtained from phenomenological models are presented and discussed.

Smooth specimen low cycle fatigue behavior of A356-T6 cast aluminum alloy with secondary dendritic arm spacing (DAS) of 36 and 58 µm was obtained under room temperature test conditions. Under strain-controlled axial fatigue conditions, cyclic strain hardening occurred for both DAS values. Hysteresis loops were skewed from 1 to 13% toward the compression side. At higher strain amplitudes the smaller DAS had slightly better fatigue resistance while at the lower strain amplitudes the fatigue resistance was essentially the same for both DAS values. Many test specimens failed outside the test gage length and were thus considered invalid tests. This large number of invalid tests was attributed to surface and near surface discontinuities. Log-log linear low cycle fatigue properties were obtained but these values should be used with caution due to apparent bi-linear log-log elastic strain-life behavior.