Patent Application
20150149105
This application claims priority to Chinese Patent Application No. 201310625573.9 filed on Nov. 28, 2013, in the Chinese Intellectual Property Office, the contents of which are incorporated by reference herein.
The subject matter herein generally relates to measurement techniques, and more specifically to a device, a method and a system of accuracy compensation for a rotating measuring machine.
A rotating measuring machine can be used in accuracy measurement. Accuracy of the rotating measuring machine is important for measuring degree of closeness of measurements of a quantity to that quantity's actual (true) value.
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures, wherein:
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure.
Several definitions that apply throughout this disclosure will now be presented.
The word “module,” as used hereinafter, refers to logic embodied in hardware or firmware, or to a collection of software instructions, written in a programming language, such as, for example, Java, C, or assembly. One or more software instructions in the modules may be embedded in firmware. It will be appreciated that modules may comprise connected logic units, such as gates and flip-flops, and may comprise programmable units, such as programmable gate arrays or processors. The modules described herein may be implemented as either software and/or hardware modules and may be stored in any type of non-transitory computer-readable storage medium or other computer storage device. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like.
The accuracy compensation system is installed and runs on a computing device 1. The computing device 1 can be a computer, a server, and any other electronic device. The computing device 1 communicates with a rotating measuring machine 2 which can perform measurements for measuring physical characteristics of an object. The rotating measuring machine 2 can rotate within a rotatable angular range. The rotating measuring machine 2 includes a working platform 3 and an image measuring device 4. The image measuring device 4 can be a charge-coupled device (CCD) or a laser scanner. The image measuring device 4 is installed above the working platform 3.
The function modules 100, 101, 102, 103, 104 of the accuracy compensation system 10 include computerized codes that can be stored in the storage device 12. When being executed by the control device 11, the function modules 100-104 can perform the functions described below.
The processing module 100 can divide the rotatable angular range of the rotating measuring machine 2 into a plurality of sub-ranges. For example, if the rotating measuring machine 2 can rotate from 0 degree to 90 degrees, then the processing module 100 can divide the overall rotatable angular range [0, 90] into sub-ranges including [0.00, 22.50], [22.51, 45.00], [45.01,67.50], and [67.51, 90.00].
The controlling module 101 can select a sub-range, rotate the rotating measuring machine 2 to an angle θ that is within the selected sub-range, capture images of the working platform 3 of the rotating measuring machine 2 after the rotating measuring machine 2 has rotated using the image measuring device 4, and generate a point cloud of the apparent shape and dimensions of the working platform 3 according to the images. For example, when the selected sub-range is [0.00, 22.50], the controlling module 101 can rotate the rotating measuring machine 2 to 20 degrees, for example. After the rotating measuring machine 2 has been rotated to about 20 degrees, the image measuring device 4 captures images of the working platform 3 for generating the point cloud of the apparent shape and dimensions of the working platform 3.
The computation module 102 can fit an initial plane according to the point cloud, and compute an actual plane of the working platform 3 according to the initial plane by iteration. In one embodiment. the iteration can use a function of:
wherein (x1, y1, z1) are coordinates of points in the point cloud of the working platform 3, “n” is a total number of the points in the point cloud, and (x2, y2, z2) are coordinates of points in the actual plane of the working platform 3.
The computation module 102 can further obtain an ideal plane of the working plane 3 in the CAD models of the rotating measuring machine 2, and compute a deviation angle between vectors of the actual plane and the ideal plane. As mentioned above, the storage device 12 can store the CAD models of the rotating measuring machine 2 rotated to any permitted angle, thus the ideal plane is a CAD model of the rotating measuring machine 2 that has been rotated to the angle θ.
The determination module 103 can determine whether the deviation angle is less than a predetermined angle, and determine whether all of the sub-ranges have been selected and tested.
The output module 104 can record the sub-range and the corresponding deviation angle into a form of a compensation report when the deviation angle is less than the predetermined angle, and output the compensation report to the display device 13. An example table depicting a compensation report is in
Referring to
At block 400, a processing module divides a rotatable angular range of a rotating measuring machine into a plurality of sub-ranges. For example, if the rotating measuring machine can rotate from 0 degree to 90 degrees, then the processing module can divide the rotatable angular range [0, 90] into sub-ranges including [0.00, 22.50], [22.51, 45.00], [45.01,67.50], and [67.51, 90.00].
At block 401, a controlling module selects a sub-range, rotates the rotating measuring machine to an angle θ that is within the selected sub-range, captures images of a working platform of the rotating measuring machine after the rotating measuring machine has been rotated using an image measuring device of the rotating measuring machine, and generates a point cloud of the apparent shape and dimensions of the working platform according to the images. For example, when the selected sub-range is [0.00, 22.50], the controlling module can rotate measuring machine to 20 degrees. After the rotating measuring machine has been rotated to 20 degrees, the image measuring device captures images of the working platform for generating the point cloud.
At block 402, a computation module fits an initial plane according to the point cloud, and computes an actual plane of the working platform according to the initial plane, by iteration. In one embodiment, the iteration can use a function of:
wherein (x1, y1, z1) are coordinates of points in the point cloud of the working platform, “n” is a total number of the points in the point cloud, and (x2, y2, z2) are coordinates of points in the actual plane of the working platform.
At block 403, the computation module obtains an ideal plane of the working plane in CAD models of the rotating measuring machine, and computes a deviation angle between vectors of the actual plane and the ideal plane. In one embodiment, the CAD models of the rotating measuring machine rotated to any permitted angle can be stored in a storage device, thus the ideal plane is a CAD model of the rotating measuring machine that has been rotated to the angle θ.
At block 404, a determination module determines whether the deviation angle is less than a predetermined angle. The method proceeds to block 406 when the deviation angle is less than a predetermined angle. Otherwise, the method proceeds to block 405 when the deviation angle is not less than a predetermined angle.
At block 405, the processing module further divides the selected sub-range into a plurality of sub-ranges. For example, when the selected sub-range is [0, 22.50], then the processing module further divides the selected sub-range [0, 22.50] into a plurality of sub-ranges including [0.00, 4.50], [4.51, 9.00], [9.01, 13.50], [13.51, 18.00], and [18.01, 22.50].
At block 406, an output module records the selected sub-range and the corresponding deviation angle into a form of a compensation report, such as that illustrated in
At block 407, the determination module determines whether all of the sub-ranges have been selected. Block 401 is repeated when any sub-range has not been selected. Otherwise, the method proceeds to block 408 when all of the sub-ranges have been selected.
At block 408, the output module outputs the compensation report to a display device of the computing device.
The embodiments shown and described above are only examples. Many details are often found in the art. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013106255739 | Nov 2013 | CN | national |
