Liberación, complementación y remodelación

In this chapter a new methodology, object shape based optical sensing methodology for optical analysis of contaminated lubricants was introduced and its applicability was verified by measuring and monitoring of coolant, gasoline and water contaminant concentrations individually, as well as mixed. To demonstrate the capability of the proposed methodology in monitoring the condition of the engine lubricant realistically, a set of oil samples was collected from a Ford Taurus under general service, with a mixed city and highway driving condition. The road test experiment was performed in real time. A novelty of the proposed methodology consists in obtaining and analysis of an optical image that combines an object with known periodic shape and a thin film of the contaminated lubricant. Introduction of an object with a priori known periodical structure

allowed reduction of 2D into 1D optical analysis. This methodology proposed to measure several parameters of the acquired optical images, such as, color of lubricant and object, object shape width at object and lubricant levels, object relative color, and object width non-uniformity coefficient, for fresh and contaminated lubricants. Estimation of contaminant presence and lubricant condition was performed by comparison of parameters for fresh and contaminated lubricants. The object shape based optical sensing

∆ W ( d im e n s io n le s s ) ∆C (dimensionless)

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methodology was verified experimentally showing ability to distinguish lubricant with 1% to 10% coolant, gasoline and water contamination. Also, it was shown that this methodology is capable of monitoring the contaminants concentration in a combined form (coolant-gasoline 0%-5%) as well. Capability of the proposed methodology was extended to establish the linkage between accumulated travelled distance and the change in the optical statistical properties of the engine lubricant.

From the results obtained, the following main conclusions can be drawn:

1. Developed object shape-based optical sensing analysis methodology is a novel approach for analysis of a synergetic effect of combined lubricant-object optical appearance. It opens new opportunities for on-line monitoring, diagnostics and control of engine lubricant condition and engine performance.

2. The engineering contribution of this work is the implementation of opto-microfluidic sensing system for extraction of optical information and monitoring the characteristics of the engine lubricating oil on-line in real time. Opto-microfluidics sensing system represents the use of advanced optical elements to increase the functionality of microfluidic devices and also the use of advanced microfluidic devices to increase the functionality of photonic devices. Such integration represents a novel approach to dynamic manipulation of optical systems with many applications in automotive fluid sensing field.

3. Implementation of systems approach, an intellectual discipline to solve complex problem, to monitor the health of engine through optical analysis of engine lubricant is a new approach in the automotive field for engine performance. This approach brings more insight into importance of engine lubricant and lubricant system and how lubricant can be used as a source of information for engine performance.

4. Addition of 1%-10% of coolant into the engine lubricant decreased the amplitude of color scale graph by almost 62%. Introduction of gasoline at the same concentration rate into the lubricant did produce any change in the amplitude of the color scale graph. Like coolant, addition of water reduced the graph amplitude by 45%.

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5. Evaluation of the relative lubricant-object color index∆C indicated that increase in the concentration of coolant, 1%-10%, provided a 46.3% decrease in∆Cvalue in a non-linear format. On the contrary, addition of gasoline has no effect on the value of

C

∆ . Like coolant, water decreased the value of ∆C by 23.65% in a linear fashion as the contaminate concentration was increased up to 10%.

6. Non-uniformity coefficient of object width∆Whas also exhibited good correlation with introduction of contaminants into the engine lubricant. Addition of coolant up to 10% into the engine lubricant lowered the∆Wvalue by almost 31%. Gasoline exhibited a similar effect on the∆W, however the reduction rate was 2.3%.

Introduction of water into the lubricant had a reduction effect on the ∆Wvalues. This reduction was much higher between 4% to 10% as to compare to 1% to 4%. Overall addition of water reduced the ∆Wvalue by 11.7%.

7. Plotting the relative lubricant-object color index∆Cvalues with non-uniformity coefficient of object width ∆Wat different contamination concentration created a 2-D

informational space for monitoring of lubricant condition. Addition of coolant at 1% and increasing to 10% lowered ∆W-∆Cvalues with a strong correlation. Since the addition of gasoline into the lubricant had no effect on the∆C, the

{

∆C,∆W

}

plot showed lack of correlation between these two parameters. Addition of water into the lubricant showed a reduction effect on the ∆W-∆C values. Monitoring the lubricant

condition from the

{

_∆C,∆W

}

informational space indicated a strong correlation and statistical dependency between these values.

8. The developed methodology was also applied for analysis of combinations of coolant and gasoline (0%-%5) contaminants. Addition of combination of coolant-gasoline (0%-5%) lowered the ∆W-∆Cvalues with good correlation. In general, addition of combined coolant and gasoline (0%-5%) into engine lubricant decreased the relative lubricant-object color index ∆Cand non-uniformity of object width ∆W

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relative lubricant-object color index ∆C values were 27.36%, while the non- uniformity of object width ∆W was lowered by 13.36%.

9. Object shape based optical analysis method was also applied for analysis of road test samples with different millage. In this study samples with 0 km, 200 km, 800 km, 1000 km, 1200 km, 1500 km, 2350 km, 3450 km, and 4200 km traveled distance were collected and analyzed in real time. The results indicated that the accumulated travelled distance directly affect the statistical parameters of the lubricant. The relative lubricant-object color index ∆Cdecreased as the accumulated travelled distance was increased from 75.18% to 73.85. The travelled distanced also decreased the non-uniformity of object width ∆Wfrom 62.85% to 61.46%. The 2-D presentation of ∆C- ∆W indicated that both statistical parameters moved in the same direction as the travelled distance increased.

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Chapter 6

6

Statistical Optical Analysis Methodology for Monitoring

Contaminated Engine Lubricant

This chapter describes an optical sensing methodology, system and statistical optics analysis applied to qualify and quantify the presence of contaminants in the engine lubricants. The statistical optics analysis is used to determine statistical characteristics of a combined object-lubricant image of a periodically structured object distorted by a thin film of turbid media. Presence of contaminants and their concentration is determined by statistical auto-characteristics and cross-characteristics. The novelty of the proposed methodology consists in introduction of an object with a known periodical structure

allowed obtaining and analysis of an optical image that combines an object with known periodic shape and a thin film of the contaminated lubricant. The priori known

periodical structure allows reduction of 2D into 1D optical analysis for on-line measurement purposes.

In document Propuesta de rehabilitación de la iglesia parroquial de Guasuntos, cantón Alausí, provincia de Chimborazo (página 131-140)