Weighing method and storage medium thereof
11519777 · 2022-12-06
Assignee
- Mettler Toledo Precision Instrument Company Limited (Changzhou, CN)
- Mettler Toledo Measurement Technology Company Limited (Changzhou, CN)
- Mettler—Toledo International Trading (Shanghai) Co., Ltd. (Shanghai, CN)
Inventors
- Jianwei Wu (Changzhou, CN)
- Hongzhi Lin (Changzhou, CN)
- Ying Zhang (Changzhou, CN)
- Guojun Xie (Changzhou, CN)
- Zheng Qian (Changzhou, CN)
Cpc classification
International classification
Abstract
In a weighing method, a weight (W) of a measured object (7) is measured. A roll angle (r) and a pitch angle (p) of a weighing scale platform (100) are read. The coordinates of a placement position (x.sub.0, z.sub.0) of the measured object are acquired. A first error (error1) caused by a weighing state according to the roll angle and the pitch angle is calculated. A second error (error2) caused by a weighing position according to the coordinates of the placement position, the roll angle (r) and the pitch angle (p) is also calculated. From these, a corrected weight (Wc) is determined.
Claims
1. A method of weighing an object on a scale comprising a weighing sensor, a weighing state identification system, a weighing position acquisition structure and a weighing process control unit, the method comprising the steps of: measuring, by the weighing sensor, a weight of the object on a weighing scale platform; reading, by the weighing state identification system, a roll angle (r) and a pitch angle (p) of the weighing scale platform; acquiring, by the weighing position acquisition structure, coordinates of a placement position (x.sub.0, z.sub.0) of the object; and calculating, by the weighing process control unit, a corrected weight (Wc) of the object by: calculating a first error (error1) caused by a weighing state according to the roll angle (r) and the pitch angle (p) calculating a second error (error2) caused by a weighing position according to the coordinates of the placement position (x.sub.0, z.sub.0) of the object, the roll angle (r) and the pitch angle (p), and applying the equation:
Wc=W/((1+error1)(1+error2))
2. The weighing method of claim 1, wherein the step of calculating the first error (error1) is by the formula:
3. The weighing method of claim 1, wherein the step of calculating the second error (error2) is by the formula:
4. The weighing method of claim 1, wherein the weighing position acquisition structure directly acquires the placement position (x.sub.0, z.sub.0) of the object.
5. The weighing method of claim 1, there are at least two weighing sensors, which provide weighing data to calculate the placement position (x.sub.0, z.sub.0) of the object by the formulas:
6. A method of weighing an object on a horizontal weighing scale platform, comprising the steps of: measuring a weight (W) of the object; acquiring coordinates of a placement position (x.sub.0, z.sub.0) on the weighing scale platform of the object; calculating a second error (error2) caused by a weighing position according to the coordinates of the placement position (x.sub.0, z.sub.0), and calculating a corrected weight (Wc) according to the second (error2),
Wc=W/(1+error2)
7. The weighing method of claim 6, wherein a calculation method for the second error (error2) caused by a weighing position is as follows:
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The above-mentioned and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, and the same reference numerals in the figures denote the same features throughout, wherein:
(2)
(3)
(4)
(5)
REFERENCE NUMERALS
(6) 100 Weighing scale body 1 Weighing scale platform 2 Weighing process control unit 3 Weighing sensor 4 Weighing position acquisition structure 5 Weighing state identification device 6 Display 7 Measured object
DETAILED DESCRIPTION OF EMBODIMENTS
(7) To make the above objects, features and advantages of the present invention more easy to understand, the present invention will be further described in detail below in conjunction with the accompanying drawings and particular embodiments.
(8) Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The same reference numerals used in all the figures denote identical or similar parts wherever possible. Furthermore, although the terms used in the present invention are selected from well-known common terms, some of the terms mentioned in the description of the present invention may have been selected by the applicant according to his or her judgement, and the detailed meaning thereof is described in the relevant section described herein. Furthermore, the present invention must be understood, not simply by the actual terms used but also by the meanings encompassed by each term.
First Embodiment
(9)
(10) As shown in
(11) a weighing scale platform 1, wherein a measured object is placed on the weighing scale platform 1 for weighing;
(12) a weighing sensor 3 located inside a weighing scale body 100, which is used for converting the weight of the measured object into deformation of an elastomer element, and then converting the deformation into an electrical signal for identification and measurement, so as to obtain the weight of the weighed object;
(13) a weighing process control unit 2 mounted on the weighing sensor 3, which is the core module of the entire weighing system, and is used for acquiring the original weighing signal output by the weighing sensor and performing signal processing on the original weighing signal; obtaining state information output by a weighing state identification device 5 and position information output by a weighing position acquisition structure 4, then calculating a weight correction value and correcting the weighing signal;
(14) the weighing position acquisition structure 4 mounted below the weighing scale platform 1, which has the same size as the weighing scale platform 1 for identifying the position of weighing, and is used for receiving instructions from the weighing process control unit 2 or outputting the position information to the weighing process control unit 2, wherein the weighing position acquisition structure 4 may be a capacitive sensing touch screen, a resistive pressure touch screen, a surface acoustic wave touch screen, an infrared sensing touch screen or a position measurement system;
(15) the weighing state identification device 5 mounted independently inside the weighing scale body 100, which is used for obtaining the horizontal or inclined state of the weighing scale body, wherein the weighing state identification device 5 may be an accelerometer, an angle sensor or a capacitive inclination angle sensor; and
(16) a display 6 which is used for displaying a weight value or other information about the measured object, and may be combined with the weighing scale body 100 to form an integral weighing scale or a separate weighing scale.
(17) For a commercial scale, generally, only one weighing sensor 3 is required, and in order to save space, the weighing state identification device 5 can be integrated in the weighing process control unit 2.
(18)
(19) When the weighing scale body 100 is inclined, a coordinate system as shown in
(20) Step 11: measuring a weight W of a measured object 7.
(21) Step 12: when the weighing scale body 100 is inclined, acquiring a roll angle r and a pitch angle p, wherein the roll angle r is the angle that the weighing scale platform 100 rotates around the x-axis, and the pitch angle p is the angle that the weighing scale platform 100 rotates about the z-axis.
(22) Step 13: calculating a weighing error error1 caused by a weighing state according to the following formula:
(23)
(24) wherein a.sub.11, a.sub.12, . . . , and a.sub.33 are weighing state correction parameters.
(25) Step 14: acquiring the coordinates (x.sub.0, z.sub.0) of the centre of gravity of the measured object 7, wherein x.sub.0 is the coordinate of the centre of gravity of the measured object 7 on the x-axis, and z.sub.0 is the coordinate of the centre of gravity of the measured object 7 on the z-axis.
(26) Step 15: calculating a weighing error error2 caused by a weighing position according to the following formula:
(27)
(28) wherein a.sub.11, a.sub.12, . . . , and a.sub.88 are weighing position correction parameters.
(29) Step 16: finally, calculating a corrected weight value according to the following formula:
Wc=W/((1+error1)(1+error2))
(30) wherein Wc is an output of the weighing system after correction, and W is an output of the weighing system before correction.
(31) In the first embodiment, the weight W of the measured object 7 is first measured in step 11, and then the weighing error error1 caused by the change of the weighing state is calculated in steps 12 and 13, and the weighing error error2 caused by the change of the weighing position is calculated in steps 14 and 15. In practice, the order of steps 11, 12 and 14 may be arbitrary, and these steps may be performed at the same time, while steps 13 and 15 need to be performed after step 12.
(32) In this embodiment, with reference to a schematic diagram of the electronic weighing structure shown in
Second Embodiment
(33) If the weighing scale platform 1 is large, a plurality of weighing sensors 3 may be mounted, and as shown in
(34) The differences between the second embodiment and the first embodiment are as follows: in the first embodiment, there is only one weighing sensor 3, and the weighing position acquisition structure 4 acquires the coordinates (x.sub.0, z.sub.0) of the measured object; while the second embodiment comprises four weighing sensors 3 which are respectively provided at four corners within the weighing scale body 100, and a weighing process control unit 2 is provided on any one of the weighing sensors 3; the weighing state identification device 5 can be independently mounted inside the weighing scale body 100, and can also be integrated in the weighing process control unit 2 of any one of the weighing sensor 3.
(35) In this embodiment, the four weighing sensors 3 constitute a position measurement system, and the position of the centre of gravity of the measured object 7 can be calculated by using weighing results of the four weighing sensors 3.
(36) According to a schematic diagram of another electronic weighing scale in the second embodiment, the calculation is performed according to the following method:
(37) Step 21: measuring a weight W of a measured object 7.
(38) Step 22: when the weighing scale body 100 is inclined, reading a roll angle r and a pitch angle p from a weighing state identification device 5.
(39) Step 23: after placing the measured object 7 on a weighing scale platform 1, reading weighing data of the four weighing sensors 3, and calculating the position (x.sub.0, z.sub.0) of the centre of gravity of the measured object according to the following formula,
(40)
(41) wherein lc1, lc2, lc3, and lc4 are weighing data of the four weighing sensors 3; a.sub.0, a.sub.1, a.sub.2, a.sub.3, and a.sub.4 are calculation parameters for the position x.sub.0; and b.sub.0, b.sub.1, b.sub.2, b.sub.3, and b.sub.4 are calculation parameters for the position z.sub.0.
(42) Step 24: repeating the above step 13 to calculate an error1 caused by a weighing state.
(43) Step 25: repeating the above step 15 to calculate an error2 caused by a weighing position.
(44) Step 26: finally, repeating the above step 16 to calculate the corrected weight value.
(45) If the weighing scale platform is larger, 6, 8, or even more weighing sensors 3 are required to be used, but the method can still be performed by the above steps.
(46) In the first and second embodiments, the weighing scale platform is a regular square structure, and if the weighing scale platform 100 is in a round or other shape, several weighing sensors 3 may be provided according to the actual shape. For example, if the weighing scale platform 100 is round, a weighing sensor may be provided at the centre of the weighing scale platform and weighing sensors may be provided at the periphery of the weighing scale platform 100.
(47) In this embodiment, with reference to a schematic diagram of another electronic weighing structure of the electronic weighing scale in
Third Embodiment
(48) The differences between the third embodiment and the first embodiment are as follows: in the first embodiment, the weighing scale platform 100 is inclined, so the roll angle r and the pitch angle p are required to be obtained; while in the third embodiment, the weighing scale platform 100 is placed horizontally, so the roll angle r=0, the pitch angle p=0, and the calculation method thereof is as follows:
(49) Step 31: reading coordinates (x.sub.0, z.sub.0) of the centre of gravity of a measured object 7, wherein x.sub.0 is the coordinate of the centre of gravity of the measured object 7 on the x-axis, and z.sub.0 is the coordinate of the centre of gravity of the measured object 7 on the z-axis.
(50) Step 32: calculating an error2 caused by a weighing position according to the following formula:
(51)
(52) wherein a.sub.11, a.sub.12, . . . , and a.sub.88 are weighing position correction parameters.
(53) Step 33: finally, calculating a corrected weight value according to the following formula:
Wc=W/(1+error2)
(54) wherein Wc is an output of the weighing system after correction, and W is an output of the weighing system before correction.
(55) The technical solutions in the present invention not only can correct the weighing value when the weighing scale platform 100 is inclined, but also can calculate a correction value for the weighing scale platform 100 placed horizontally, which have a wide application range, a simple structure, a low cost, thereby avoiding the manual labour of the operator and greatly improving work efficiency.
(56) Through the above description of the weighing methods, it can be clearly understood by those skilled in the art that the present invention can be implemented by means of software and necessary hardware platforms. Based on such understanding, the technical solutions of the present invention, essentially or for a contribution part in the prior art, can be embodied in the form of a software product, wherein the computer software product may be stored in a storage medium, including but not limited to a ROM/RAM (Read Only Memory/Random Access Memory), a magnetic disk, an optical disk, etc., and may include several instructions for causing one or more computer devices (which may be a personal computer, a server, or a network device, or the like) to perform the method described in the various embodiments or in certain parts of the embodiments of the present invention.
(57) The weighing method of the present invention may be described in the general context of the computer-executable instructions to be executed by a computer, such as a program module. Generally, the program module includes programs, objects, components, data structures, and so on that execute particular tasks or implement particular abstract data types. The present invention may also be practiced in a distributed computing environment in which the tasks are executed by remote processing devices that are connected via a communications network. In the distributed computing environment, the program module may be located in local and remote computer storage media including the storage device.
(58) While the particular embodiments of the present invention have been described above, a person skilled in the art should understand that these are merely illustrative, and that the scope of protection of the present invention is defined by the appended claims. Various alterations or modifications to these embodiments can be made by a person skilled in the art without departing from the principle and essence of the present invention; however, these alterations and modifications all fall within the scope of protection of the invention.