FIELD OF INVENTION

The invention relates generally to method for testing of meters, such as gas, electric and water meters, and more particularly, to method for testing meters in a test bench to test accuracy of the meter.

BACKGROUND OF THE INVENTION

Meters are widely used by utility companies to measure the consumption of their products by residential and commercial customers. This usage information must be collected on a periodic basis in order to perform billing. Therefore, it is important to ensure that the meter is accuracy to track an amount of consumed flow.

There are many different types of meters, all using different principle to measure a flow such as water. However, it is often desirable to test meters on a test bench, run an absolute know volume of water through the meter or group of meters, and compare their registered volumes to that of the known volume. If the results shown an acceptable deviation from the known volume, then meter is working correctly, if the deviation is unacceptable, it is not.

Example of such method to test meters is found in US 7349588 B2 which describe a method for reading a meter comprising: capturing an image of a face of the meter; and performing optical character recognition using at least one template in order to recognize digits displayed on the meter for testing the meter. However, this method is in poor accuracy due, for example, when the numbers of the meter in transition and therefore hidden or obscured from the camera vision. It is an object of the invention to address the disadvantages and problems associated with the prior art. The present invention is to provide a method for testing a meter includes capturing at least one image of the meter, and analysing the image for obtaining the reading in order to determine accuracy of the meter.

Another object of the present invention is to provide a method adapted to read and recognise partially obscured characters, that is, adjacent numbers and measuring scales in course of transition.

SUMMARY OF THE INVENTION

This invention provides a method for testing a meter having a rotatably digit display with a plurality of decimal value marks comprising steps of: capturing at least two images of the meter by an image capturing device; locating a position of the display in the images by a position processing unit; determining a barcode of the meter by a barcode processing unit; determining at least one digit displayed on the display from the first image by a digit processing unit, and/or, for a digit which is partially visible, correlating digits displayed on the following images with the first image to determine the digit that partially displayed on the first image by a digit processing unit; determining at least one decimal value indicated by a pointer on the decimal value mark from the first image using a decimal processing unit, or, for a pointer pointed in between the two decimal value marks, calculating a decimal value using a ratio of a distance of the pointer from the nearest decimal value mark to a distance between the two adjacent decimal value marks by a decimal processing unit; and outputting at least one reading of the meter by combining of the digit and the decimal value using an output unit to determine accuracy of the meter.

Preferably, the method further comprising step of comparing the reading of the meter with a reference meter to test accuracy of the meter.

Preferably ten images are captured for one reading from the meter. The digit, decimal and/or barcode processing unit or any combination thereof can be an optical character recognition system. The image capturing device can be a camera. The meter can be under test with a test bench. The present invention consists of features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings, it being understood that various changes in the details may be made without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify various aspects of some embodiments of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the accompanying drawings in which:

Figure 1 shows a process flow diagram of a method for testing a meter in accordance with an embodiment of the invention;

Figure 2 shows a display of the meter in a situation which some of its digits are partially visible; and

Figure 3 shows the display of the meter in a situation a pointer is ponied in between adjacent decimal value markings.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates generally to method for testing of meters, such as gas, electric and water meters, and more particularly, to method for testing meters in a test bench to test accuracy of the meter.

Meters such as gas, electric and water meters are configured to measure volume of a fluid flowing through the meter thereby measuring fluid consumption. Such meters can be tested in a test bench to verify accuracy. In the test bench, a fluid is pushed through at least one of the meter to be tested and a reference meter. The reference meter is configured to generate a very accurate reference volume. Similarly, the meter under the test measures the volume of fluid that flows through itself and generates a reading. Ideally, the reading would be identical to the reference volume. However, the reading may be varied from the reference volume. If the reading of the meter within an acceptable deviation from the reference volume, then meter is working correctly, if the deviation is unacceptable, it is not.

Referring now to Figure 1, a flow chart illustrating a method for testing the meter in accordance with an embodiment of the invention is presented. The method begins at step (1) with passing the fluid in the test bench containing at least one of the meter. For example meter is a meter having a rotatably digit display as shown in Figure 2. The display comprises of a plurality of wheels (not shown), each of the wheel is provided with a series of digits "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"in sequential order. The wheels are arranged to rotate at different speeds, such that first wheel rotates ten times faster than the next wheel and so on. In addition, the display has a plurality of decimal value marks (13) with a pointer (14). Thus, the display represent a number of digits, combined with a decimal value, such as a reading of "3746.85123". However, the construction of meter is not restricted to only this case. It is possible to employ various construction of meters other than the construction as described.

In block (2), at least two images of the meter are captured by an image capturing device. For example image capturing device is a camera such as digital camera or other type of cameras. Preferably, the images captured is a full face image of face of the meter. The images may be taken at any chosen interval. For example, ten images can be taken at few seconds interval which is short enough so that the wheels of the display will move in different position between two images. Next, the display of the meter in the images captured is located by a position processing unit. This can be done, for example, by pattern matching of locations on the captured image with a pattern typical of a display of a meter.

In block (3), a barcode (12) of the water meter is determined by a barcode processing unit. The barcode processing unit performs optical character recognition on barcode (12) labelled to the meter. In block (4), the digits displayed on the display from the first image is determined by a digit processing unit through the optical character recognition. In block (5), the digits in the first image which may be in partially shown or in transitional between two adjacent digits when the image is captured. In situation shown in Figure 2, the digit "5" is partially shown. Then, in block (6), digit displayed in the following images such as second image or others will be used to find the digit in partially shown in the first image. This will indicate that the digit in the following image is the next digit of the first image. When the digit "5" is partially shown, the digit "6" will be appear in the next images captured such as the fifth image captured. Thus, correlating the digit displayed on the fifth image captured with the first image to determine the digit was partially displayed on the first image. The digit on the first image should be "5". This step can be repeated until all the digits partially shown or in transition to be determined. If there are no digit in transition to be determine, in block (7), decimal value of the meter of the first image is determined. The decimal value mark (13) pointed on the meter from the first image by a decimal processing unit. Sometimes, for the pointer (14) is pointed in between two adjacent marks (13). The decimal value is determined through appropriate calculation, involving for instance a ratio. For example, as shown in Figure 3, the decimal value is determined using as equation:

Decimal value

Distance of pointer with the nearest decimal value marking (15) Distance between two adjacent decimal value marings (16)

In block (10), a resulting meter reading of the meter is obtained by combination of the determined digits and decimal value for the first image using an output unit. In a final step (11), comparing the resulting meter reading is compared with reading of a reference meter to test accuracy of the meter by a matching unit. In alternative embodiments, digit determination and decimal value determination can be performed in different sequence. For example, instead of the digits displayed on the display from the first image is determined by a digit processing unit in block (4) before the decimal value of the meter is determined in block (7), the steps can be performed inverted as the decimal value of the meter is determined in block (7) before the digits displayed on the display from the first image is determined by a digit processing unit in block (4).

The present invention may be embodied in other specific forms without departing from its essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore indicated by the appended claims rather than by the foregoing description. All changes, which come within the meaning and range of equivalency of the claims, are to be embraced within their scope.