Measuring and testing – Meteorology – Precipitation
Reexamination Certificate
2000-02-22
2002-11-05
Fuller, Benjamin R. (Department: 2855)
Measuring and testing
Meteorology
Precipitation
C073S170160
Reexamination Certificate
active
06474153
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a predicting system continued to predict an inflow volume of rainwater, which is necessary to operate pumps arranged in a sewage treatment plant in order to drain rainwater in raining, or to control to open or close gates arranged in paths to temporary storing facilities for rainwater (storage basin, storing ducts, adjusting ponds and so on) in order to avoid flooding disasters.
2. Description of the Related Art
The sewage treatment plant not only treats sewage but also plays a role of preventing disasters caused by stormwater. Thus, the sewage treatment plant is an important facility in order to secure urban hygiene and environmental safety. Usually, rainwater is drained off from sewage ducts to a sea or a river via draining pumps arranged in a pump facility or a sewage treatment plant. Thus, it is important to determine the number of the draining pumps to be operated, based on an inflow volume of rainwater into the pump facility or the sewage treatment plant.
Recently, since residential areas have become denser and paved roads have spread, a greater part of rainwater has flown into the sewage ducts. Then, since the pumps have limitations of capacities for draining off the rainwater, temporary storing facilities for rainwater such as storing ducts or adjusting ponds have been provided more often. In the case of using the temporary storing facilities of rainwater, it is important to suitably control open apertures of respective gates to the storing facilities of rainwater.
In order to suitably determine the number of pumps to be operated and efficiently control the open apertures of the respective gates to the storing facilities of rainwater, it is desired to accurately predict an inflow volume of rainwater into the pump facility, the treatment plant or the storing facilities of rainfall and to use the predicted data for the determination and the control.
As the temporary storing facilities for rainwater have developed only recently, no prior art concerning the control of the gates is found. However, concerning the determination of the number of pumps to be operated, there are known two types, which are a type not using a prediction of an inflow volume of rainwater into the pump facility and another type using the prediction of the inflow volume of rainwater into the pump facility.
The type not using the prediction of the inflow volume of rainwater into the pump facility includes a method for determining the number of pumps to be operated based on measured data of rainfall and intuition of an operator of the pump facility, and a method for determining the number of pumps to be operated based on a water level measured by a water gauge arranged in a pump well of the pump facility.
The type using the prediction of the inflow volume of rainwater into the pump facility includes a method of measuring amounts of rainfall that has fallen by the present time by a plurality of rainfall gauges arranged on the ground and predicting the inflow volume of rainwater by using an RRL method. In addition, the type includes a method of constructing a prediction model by estimating parameters of an ARMAX model, which represents a relationship between the rainfall volume and the inflow volume of rainwater, by an ARMAX identification method and predicting the inflow volume of rainwater based on the prediction model. The type also includes a kinematic-wave method. Herein, the RRL method and the kinematic-wave method are called white-box-models. On the other hand, the ARMAX identification method is called a black-box-model.
The RRL method is a method for calculating the inflow volume of rainwater, which was developed by the England Road Laboratory. The RRL method is explained hereinafter.
In the RRL method, a duct chart (Sewer Network Diagram) is made wherein hydraulic features of ducts in an objective area, for example respective lengths, respective diameters and respective inclinations of the ducts, are written. Then, assuming that the whole duct chart is a single basin, a lowermost point of the basin is selected as a point p for calculating an inflow volume. Then, flow rates in main collecting ducts, open ducts and so on are calculated. Then, the so-called time-area curves are defined and written in such a manner that a time flowing between each two of neighboring curves of the rainwater toward the point p is equal to a time necessary to calculate an inflow volume of rainwater. Areas divided by the time-area curves are calculated as time-differentiating-areas Ai[m
2
].Thus, a time-area chart is made. The above operations are conducted manually.
Then, a rainfall curve (chart) is defined and written based on rainfall intensities I
i
[mm/s] in the basin for respective unit times i for calculating the inflow volume. A flowing coefficient C that represents a flowing ratio is given as a fixed value defined from a using condition of the ground in the basin. A provisional inflow volume of rainwater Pi is calculated from the made rainfall curve and the made time-area chart, according to the following equation (1).
Pi
=
∑
k
=
1
n
{
C
×
I
i
-
k
+
l
×
A
k
}
(
1
)
In general, the rainwater generated by the rainfall does not immediately flow into the facility, but is temporarily stored in the ducts and flows into the facility after that. Thus, the inflow volume of rainwater is calculated by substituting the provisional inflow volume of rainwater Pi for an equation representing a relationship between the stored amount of rainwater and the inflow volume of rainwater. The equation representing the relationship between the stored amount of rainwater and the inflow volume of rainwater is explained as below.
S
(
t
)=
KQ
(
t
)
n
(2)
(K, n: CONSTANTS OF THE BASIN)
ⅆ
S
(
t
)
ⅆ
t
=
P
(
t
)
-
Q
(
t
)
(
S
:
STORED
AMOUNT
[
m
3
]
P
:
PROVISIONAL
INFLOW
VOLUME
[
m
3
/
s
]
Q
:
INFLOW
VOLUME
[
m
3
/
s
]
(
3
)
The equation (2) is called a kinematics (motion) equation. The equation (3) is called a continuity equation. Usually, the following equation (4) which is obtained by differentiating the equation (3) is used for calculating the inflow volume of rainwater.
Q
i
+
2
Δ
t
S
i
=
(
Pi
+
Pi
-
1
)
-
Q
i
-
1
+
2
Δ
t
S
i
-
1
(
Δ
t
:
differential
time
)
(
4
)
The inflow volume of rainwater calculated by the above manner is finally determined as an inflow volume of rainwater Qi of the point p for calculating the inflow volume of rainwater.
In addition, there is a modified RRL method wherein a point (view) of effective rainfall, wherein a pervious area and an impervious area is divided, is added to the RRL method. In the modified RRL method, the relationship between the stored amount of rainwater and the inflow volume of rainwater is modified with respect to the RRL method. Concerning the basic processes, the modified RRL method is similar to the RRL method. Furthermore, there is an expanded RRL method wherein the point of effective rainfall is modified with respect to the modified RRL method, and wherein points of introducing a function depending on a time and of dividing the basin are added to the modified RRL method.
Next, the ARMAX identification method is explained as below.
In the ARMAX method, a transfer function model as shown in
FIG. 11
is defined as a function representing a relationship between the rainfall volume and the inflow volume of rainwater. In
FIG. 11
, u represents data of the rainfall volume, y represents data of the inflow volume of rainwater, and e represents a measurement error that can not be observed. In addition, the equations (5), (6) and (7) are satisfied.
A
(
z
)=
a
n
z
n
+a
n−1
z
n−
Nagaiwa Akihiro
Nakada Masajiro
Tsutsumi Masahiko
Yamanaka Osamu
Allen Andre J.
Fuller Benjamin R.
Kabushiki Kaisha Toshiba
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
LandOfFree
Predicting system and predicting method configured to... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Predicting system and predicting method configured to..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Predicting system and predicting method configured to... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2923369