TANDELTA OQSExISG2, Руководство пользователя

Страница: 118 / 130

Page | 116
Figure 84 - Oil Top-Up Intervention
12.5 Rate of Change (ROC)
Calculating Rate of Change (RoC) of oil condition is necessary to utilise some of the more
advanced algorithms for integrated oil condition logic.
You can use the following logic to set up a third-party device to show the rate of change in the
oil condition:
Instant RoC = Average change in oil condition for last 5 minutes.
Median RoC = Average change in oil condition for last 6 hours. (Should cover at least 60
data points)
Lifetime RoC = Average change of all oil condition readings. (Should cover at least 60
data points)
This equation is a relatively expensive task on small processors, so may not be possible for all
devices. Below is the RoC implementation which is mathematically correct to the definition of
“rate of change over time”.
𝑅 =
∑ (𝑡
𝑖
− 𝑇̅)(𝑜
𝑖
− 𝑂̅)
𝑐+𝐼
𝑖=𝑐
∑ (𝑡
𝑖
− 𝑇̅)
2
𝑐+𝐼
𝑖=𝑐
𝑅
Rate of
change
Rate of change value
𝑖
Iterator Value iterator
𝐼
IterMax Number of records to consider (ROC time period in minutes / log
interval in minutes)
𝑐
Clock Current time in minutes / log interval in minutes
𝑡
Time Time at record
𝑖
(3)
(3)