Performance Analysis

October 3, 2022

■Filtering for ship performance analysis

Performance analysis is the process of determining the relationship between ship speed and fuel consumption or between ship speed and main engine output based on daily noontime reports by crew or automatically measured data. The relationship between vessel speed and fuel consumption is the primary factor for analyzing the operational balance in unit time, excluding capital and labor costs, so the performance analysis is the basis for the voyage balance.

In this context, filtering is one of the work processes of performance analysis, and the purpose of the process is extracting valid data from a group of data. For example, by filtering data using weather and sea conditions such as wind speed and wave height as threshold values, only data that is unaffected by wind and waves can be extracted, enabling a clear understanding of the relationship between vessel speed and fuel consumption. This is an important process that greatly affects the results of performance analysis.

Figure 1)　Effects of filtering (Filtering reduces variation and extracts a clear correlation between vessel speed and fuel consumption)

■Conventional filtering

In conventional filtering methods, for example, data is narrowed down by setting uniform conditions for wind power, wave height, etc., and the relationship between ship speed and fuel consumption is captured from the remaining data. However, because the period of original data, hull condition, and sea conditions encountered differ, the results obtained by filtering under uniform conditions can vary, and in many cases manual correction is required.

Figure 2) Work process with conventional filtering (manual filter adjustment required)

■Optimal filtering logic

In contrast, the optimal filtering logic enables accurate filtering of any data in a short period of time without manual work. In addition, this algorithm can be applied not only to ship performance analysis, but also to other equipment data and data from other industries, and is expected to be used in other fields.

Figure 3) Work process with optimal filtering logic

(Writer: Tetsuo Yanagida)

Registration number 6977186 (Japan Platform for Patent Information)