Correction method for optical centering device of measurement base

Abstract

The invention belongs to the technical field of measurement, and relates to a correction method for an optical centering device of a measurement base. A to-be-corrected base centering device is installed on the tripod and leveled; a limiter is installed on the top of the base to be corrected; two top cross rods perpendicular to each other are embedded in the top face of the limiting stopper, and the intersection point of the two top cross rods is located in the center of the top of the limiting stopper. Two bottom cross rods are arranged below the two top cross rods; the two bottom cross rods are vertically arranged, and the two bottom cross rods are respectively suspended right below the two top cross rods through equal-length vertical lines; under the action of gravity and a vertical line, the intersection position of the two bottom cross rods and the center of the limiting stopper are located on the same vertical line; and observing whether the central mark of the field of view of the centering device coincides with the cross point of the two bottom cross rods or not through the eyepiece of the centering device. The correction principle is simple and visual, the operation process is simple, correction can be achieved anytime and anywhere, and it is ensured that the centering performance of the reference centering device meets the requirement all the time.

Description

Technical Field

[0001] The present invention belongs to the technical field of measurement, and particularly relates to a calibration method for an optical centering device of a measurement base. Background Art

[0002] In measurement work, especially in precision measurement work, a measurement base is an essential device; the working principle of the measurement base is to make the center of the component (prism, measuring instrument, etc.) installed above the base coincide with the center of the control point below the base through a built-in supporting centering device. Under normal erection height, the allowable deviation value is usually 1.0 mm. The quality of the centering accuracy of the centering device will directly affect the success or failure of the measurement work.

[0003] Currently, there are two types of measurement bases: the first type is that the centering device and the base of the measurement base are two separate independent components. After the centering device is installed on the base of the measurement reference, it can rotate horizontally 360°. The centering devices of most total stations and theodolites are similar to this structure, as shown in Figure 1 ; the second type is that the centering device and the base of the measurement base are fixed together, and the centering device cannot rotate, as shown in Figure 2 ; however, the centering device is prone to deviation due to external forces during transportation and use. Therefore, before, during, and after each measurement work, the centering device needs to be calibrated to ensure that its centering accuracy is always in a qualified state; currently, the calibration of the centering devices of the above two types of bases is mainly carried out through the following methods: for the calibration of the centering device of the first type of base, there are mainly two ways. One way is to send it to a professional verification institution for calibration through a special calibration platform in the laboratory; the other way is that the surveyor uses the method of rotating the centering device in a cycle and gradually approaching on the measurement site for calibration, which is also the commonly used method for this type of centering device currently; for the calibration of the centering device of the second type of base, currently it can only be sent to a professional verification institution for calibration through a special calibration platform in the laboratory, and the surveyor cannot calibrate it by himself on the measurement site; therefore, there are the following defects and deficiencies in the calibration of the centering devices of the above two types of bases currently: 1) The calibration method of using the rotating centering device to gradually approach in a cycle is cumbersome and inefficient in operation, and it is only applicable to the calibration of the centering device of the first type of reference, and this method cannot be used for the centering device of the second type of base; 2) Sending it to a professional verification institution for calibration through a special calibration platform in the laboratory. Although this method is applicable to both the centering device of the first type of base and the second type of centering device, its capital cost and time cost are too high, and the calibration work cannot be carried out anytime and anywhere. On the other hand, after the base is calibrated by this method, it needs to be transported from the calibration institution to the use site, and the centering performance of the base may change during this process. Summary of the Invention

[0004] The object of the present invention is to provide a calibration method for the optical centering device of a measuring base, so as to solve the problems proposed above.

[0005] The above technical object of the present invention is achieved through the following technical solutions: A calibration method for the optical centering device of a measuring base, the centering device to be calibrated is installed on a tripod and leveled; it is characterized in that: a limiter is installed on the top of the base to be calibrated; two mutually perpendicular top crossbars are inlaid on the top surface of the limiter, and the intersection point of the two top crossbars is located at the center of the top of the limiter; two bottom crossbars are arranged below the two top crossbars; the two bottom crossbars are vertically arranged, and the two bottom crossbars are respectively suspended directly below the two top crossbars by equal-length vertical lines; under the action of gravity and the vertical lines, the position where the two bottom crossbars intersect and the center of the limiter are on the same plumb line; through the eyepiece of the centering device, observe whether the center mark in the field of view of the centering device coincides with the intersection point of the two bottom crossbars; if they coincide, it means that the performance of the centering device is good and no adjustment is required; if the coincidence degree is poor, adjustment is required.

[0006] The top surface of the limiter has two mutually perpendicular limiting grooves for respectively cooperating with the two top crossbars; the depths of the two limiting grooves are different to facilitate the inlaying of the two top crossbars.

[0007] A central limiting cylinder is arranged at the intersection of the two limiting grooves, and a central through hole for the central limiting cylinder to pass through is provided at the center of the top crossbar.

[0008] Quick threading holes for cooperating with equal-length vertical lines are respectively arranged at both ends of the top crossbar and the bottom crossbar.

[0009] A calibration method for the optical centering device of a measuring base provided by the present invention has the following beneficial effects: (1) The calibration principle of this method is simple, intuitive, and the operation process is simple.

[0010] (2) This method is particularly suitable for calibrating the second type of base centering device, that is, the centering device that cannot rotate.

[0011] (3) For the first type of base centering device, this method can complete the precise calibration of the centering device with one calibration operation, without the complicated calibration operations of repeated cycles in the conventional calibration method.

[0012] (4) Compared with the method of calibrating through a specially made calibration platform in the laboratory by sending it to a professional calibration institution, the capital and time costs required by this method can be ignored.

[0013] (5) This method has low requirements for the professional level of the calibration personnel. On-site surveyors with basic surveying knowledge can complete the calibration work according to this method.

[0014] (6) This method can achieve calibration anytime and anywhere, ensuring that the centering performance of the reference centering device always meets the requirements.

[0015] (7) With the help of common surveying components, this method can also be used for the calibration of laser centering devices of total stations, theodolites and other equipment. Description of the Drawings

[0016] Figure 1 and 2 is a schematic structural diagram of a centering device in the prior art.

[0017] Figure 3 is a schematic structural diagram of the position limiter in the present invention.

[0018] Figure 4 is Figure 3 a top view of

[0019] Figure 5 is Figure 3 a front view of

[0020] Figure 6 is Figure 3 a side view of

[0021] Figure 7 is a schematic structural diagram of the top crossbar.

[0022] Figure 8 is a schematic structural diagram of the bottom crossbar.

[0023] Figure 9 is a usage state diagram of the present invention.

[0024] In the figure: 1, limit groove; 2, central limit cylinder; 3, top crossbar; 4, central through hole; 5, quick wire threading hole; 6, bottom crossbar; 7, equal-length vertical line; 8, centering device; 9, position limiter. Detailed Embodiments

[0025] The present invention will be described in detail with reference to the accompanying drawings and specific embodiments: As shown in Figure 9As shown in the figure, a calibration method for the optical centering device of a measuring base. Install the centering device 8 of the base to be calibrated on a tripod and level it. As is well known, the higher the height of the base installation, the greater the deviation generated by the centering device. Therefore, when calibrating, the installation height of the base can be slightly higher than its normal use height. Install a limiter 9 on the top of the base to be calibrated. The top surface of the limiter is inlaid with two mutually perpendicular top crossbars 3, and the intersection point of the two top crossbars 3 is located at the center of the top of the limiter. Two bottom crossbars 6 are arranged below the two top crossbars 3. The two bottom crossbars 6 are vertically arranged, and the two bottom crossbars 6 are respectively suspended directly below the two top crossbars 3 by equal-length vertical lines 7. Under the action of gravity and the vertical lines, the position where the two bottom crossbars 6 intersect is on the same vertical line as the center of the limiter. Through the eyepiece of the centering device, observe whether the center mark of the centering device field of view coincides with the intersection point of the two bottom crossbars. If they coincide, it means the centering device has good performance and does not need adjustment. If the coincidence degree is poor, adjustment is required. As is well known, there are adjustment bolts on various centering devices. By turning the adjustment bolts on the centering device, adjust the center mark of the centering device field of view to coincide with the intersection point of the two bottom crossbars, that is, complete the calibration of the centering device.

[0026] As Figures 3 - 6 shown, the top surface of the limiter has two mutually perpendicular limiting grooves 1 for respectively cooperating with the two top crossbars 3. The depths of the two limiting grooves 1 are different, and the widths are both 2 mm, which is convenient for inlaying the two top crossbars. The bottom of the limiter has different structural forms for supporting installation with different types of bases.

[0027] At the intersection of the two limiting grooves, there is a central limiting cylinder 2 with a diameter of 1 mm. The center of the top crossbar has a central through hole for the central limiting cylinder to pass through.

[0028] The dimensions of the top crossbar are: its width is 2 mm, its thickness is 2 mm, its length is 300 mm, there is a round hole with a diameter of 1 mm in the center, and there are quick wire-passing holes at both ends for convenient wire threading.

[0029] The dimensions of the bottom crossbar are: the diameter is 1 mm, the length is 300 mm, and there are quick wire-passing holes at both ends for convenient wire threading.

[0030] The equal-length vertical lines, whose lengths are adjusted according to the normal installation height of the base, are generally about 1.5 m long. Each vertical line is knotted at both ends, and the size of the knot is matched with the quick wire-passing hole.

[0031] Furthermore, the calibration work of the centering device (laser centering device) of instruments such as total stations and theodolites can be completed by this method supplemented with common measuring components: First, install the base of the total station and other instruments on the tripod and level it. Then, remove the centering device of the first type of base, install it on the base of the already set-up total station, and complete the calibration of this centering device according to this method. Then, mark the correct center mark on the ground through the calibrated centering device. Then, remove the centering device and install the total station main unit on the base. Finally, observe whether the centering device or laser centering device of the total station coincides with the ground mark. If not, adjust the adjustment bolts of the centering device to make it coincide, thus completing the calibration work of the total station centering device.

Claims

1. A calibration method for the optical centering device of a measuring base. Install the centering device of the base to be calibrated on a tripod and level it. It is characterized in that: Install a limiter on the top of the base to be calibrated; two mutually perpendicular top crossbars are inlaid on the top surface of the limiter, and the intersection point of the two top crossbars is located at the center of the top of the limiter; two bottom crossbars are arranged below the two top crossbars; the two bottom crossbars are vertically arranged, and the two bottom crossbars are respectively suspended directly below the two top crossbars by equal-length vertical lines; under the action of gravity and the vertical lines, the position where the two bottom crossbars intersect is on the same plumb line as the center of the limiter; through the eyepiece of the centering device, observe whether the center mark in the field of view of the centering device coincides with the intersection point of the two bottom crossbars; If they coincide, it means that the centering device has good performance and does not need adjustment; if the coincidence degree is poor, adjustment is required.

2. The calibration method of an optical centering device for a measuring base according to claim 1, characterized in that: The top surface of the limiter has two mutually perpendicular limiting grooves for respectively cooperating with the two top crossbars; the depths of the two limiting grooves are different to facilitate the inlay of the two top crossbars.

3. The calibration method of an optical centering device for a measurement base according to claim 1, characterized in that: A central limiting cylinder is arranged at the intersection of the two limiting grooves, and a central through hole for the central limiting cylinder to pass through is provided at the center of the top crossbar.

4. The calibration method of an optical centering device for a measuring base according to claim 1, characterized in that: Quick threading holes for cooperating with the equal-length vertical lines are respectively arranged at both ends of the top crossbar and the bottom crossbar.

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