Slow Dynamic Slope method in internal combustion engine benchmarking

Abstract

Enlarged engine control complexity made the full-factorial steady-state testing approach extremely time consuming and hardly applicable under actual industry demands. Slow dynamic slope (SDS) method is one of many approaches with a potential for considerable testing time savings, with its own benefits and drawbacks. This paper puts in focus SDS approach and evaluates its applicability, potentials and accuracy for fast estimation of engine steady-state maps. The presented research is based on an extensive experiment conducted on a small passenger car compresion ignition engine. Being the method that uses quasi-stationary sweeping of the engine, SDS test cycle durations in the range from 120-600 seconds are used in order to test the method and draw conclusions on its applicability. It is shown that well shaped SDS testing cycle can provide a rather good estimate of the steady-state operating points very quickly, with a negligible or very small loss of accuracy. The analysis is conducted both on fast responding variables and those that are heavily influenced by process inertia. This led to some suggestions on how to form a criterion for the SDS gathered data quality evaluation and SDS testing cycle correction.

Stationary Test Plan Optimisation Using Slow Dynamic Slope Engine Screening

“…In doing so, the level of prior knowledge about the examined IC engine, or any other system under test, will increase rapidly utilising this type of dynamic test. In the publication [3] and in the previous research of the authors [14,15], the theoretical foundations of the SDS mode of excitation are presented. Figure 1 shows the SDS excitation 𝑢(𝑡) and the response 𝑦(𝑡) of an arbitrary linear system.…”

Continuous slow dynamic slope approach for stationary base internal combustion engine mapping

“…In the research [6], a classical SDS was configured as follows: -At demanded constant engine speed, engine load was set to value in the middle of operational load span and settled until stationary operation. -For a defined ramp gradient, the engine load was increased to the maximum load, maintained at maximum level for a few seconds and decreased to full motoring with the same, but negative, gradient.…”

“…The main topic of this paper is the introduction of fully dynamic SDS experiments, and the comparison of system excitation and responses obtained this way with classical approach which was presented by Keuth et al [5] and further analyzed by authors in [6]. Also, some guidelines on potential problems which may occur during SDS engine testing and during data analysis will be given.…”

“…Also, some guidelines on potential problems which may occur during SDS engine testing and during data analysis will be given. This paper relies significantly on the authors' pervious research [6], in which additional explanations and theoretical principles can be found.…”

Dynamic interaction between the structure and the trolley of high performance gantry cranes

“…U ovom radu korišćena je instalacija koja je formirana za potrebe eksperimentalnih istraživanja u okviru projekta NPEE-290025 i Više detalja o eksperimentalnoj instalaciji i specifičnostima primenjene opreme može se naći u radovima grupe autora sa Katedre za motore MFB [195,[206][207][208][209][210][211][212][213][214].…”