Method for expanding view field angle of photoelectric deflectometer

Abstract

The invention discloses a method for expanding a field angle of a photoelectric deflection instrument, which comprises the following specific steps: step 1, mounting a rotary steering engine, step 2, interconnecting the steering engine and a control system, step 3, switching measurement targets at different angles through rotation of the steering engine, step 4, collecting data, namely mounting a steering engine at the bottom of a traditional photoelectric deflection instrument, and controlling the steering engine to rotate. The steering engine is used for driving the photoelectric deflection instrument to rotate, the rotation angle of the steering engine can be obtained through the position encoder of the steering engine, switching of the left side and the right side of the photoelectric deflection instrument rotating to two or more fixed positions is achieved, and a reference target in a specific shape can be shot every time the photoelectric deflection instrument is switched to different positions. And after each switching to the corresponding position, the relative position change of the plurality of measurement targets and the reference target in the picture can be calculated, and switching and data acquisition are performed in sequence, so that the deformation data of the large-range measurement targets can be monitored by one photoelectric deflection instrument.

Description

Technical Field

[0001] The invention relates to the technical field of photoelectric deflectometers, in particular to a method for expanding the viewing angle of a photoelectric deflectometer. Background Art

[0002] A photoelectric deflectometer, or machine vision deformation monitoring device, utilizes image recognition technology to calculate the displacement of a target (a characteristically shaped target) by observing pixel changes in the horizontal and vertical directions of an image. Due to different scenario requirements, photoelectric deflectometers have different lens focal lengths to choose from, such as telephoto lenses for distant targets and short-focus lenses for close-up targets. In practical applications, a photoelectric deflectometer often requires both long-range detection and a wide field of view (capturing more targets), so as to maximize coverage of all targets with a single photoelectric deflectometer.

[0003] Traditional methods typically use multiple devices to cover long distances and wide-angle fields of view, or use wide-angle lenses such as 5mm and 10mm. This approach increases the number of hardware devices (cost) and production cycle (customizing wide-angle lenses). Furthermore, using only wide-angle lenses can result in images that are too small for distant targets, affecting image quality. Increasing the target area can also affect installation. Summary of the Invention

[0004] The object of the present invention is to provide a method for expanding the field of view angle of a photoelectric deflectometer. The specific steps of the method for expanding the field of view angle of a photoelectric deflectometer are as follows: Step 1: Install a rotary servo. A rotary servo with a position encoder is designed at the bottom of the photoelectric deflectometer to achieve horizontal rotation of the photoelectric deflectometer. Step 2: Interconnect the servo with the control system. The servo has a position encoder that controls rotation and reports position via the RS485 communication line. The control system can send rotation commands via the RJ45 interface line. Based on the encoder data reported by the servo, when the servo rotates to the set position, the control system issues a stop rotation command. Step 3: Use the servo to rotate and switch the measurement targets at different angles. The reference target is placed in the center of the system during actual installation and is distinguished by a special shape. The reference target is △, and the measurement point target is ○-shaped. The system automatically distinguishes whether it is a reference target or a measurement point target based on the characteristics of the target imaging. Step 4, data acquisition, when the system is working, the photoelectric deflection instrument respectively acquires the deflection settlement data of the targets on the left and right sides of the installation position, and the positions (X1, Y1), (X2, Y2)... (Xn, Yn) of the measurement targets 1-N at the current time in the image can be obtained, the position of the reference target in the image is (Xbase, Ybase), and the horizontal change data of each measurement point relative to the reference point is X1-Xbase, X2-Xbase... Xn-Xbase, and the vertical change data of each measurement point relative to the reference point is Y1-Ybase, Y2-Ybase... Yn-Ybase, thereby completing the measurement work of the photoelectric deflection instrument.

[0005] Preferably, when installed on site, the basic target needs to be designed at the middle position of the system to reduce cumulative error, and multiple reference targets can also be used, and when imaging for the first time, the appropriate angle needs to be adjusted, and the number of rotation times is as small as possible, and the data of all measurement points and reference points are collected, after the shooting angles are adjusted, the position encoder data of the steering engine is collected, recorded and set in the upper computer software as the point position information of the automatic inspection system.

[0006] Preferably, the data acquisition adopts a time division multiplexing acquisition mode.

[0007] Preferably, the target differentiation can also be configured manually, and it is selected whether the measurement point target or the reference target is selected.

[0008] Preferably, the control system is one of an industrial computer or a gateway controller.

[0009] Compared with the prior art, the beneficial effects of the present application are that the present application installs a steering engine at the bottom of the traditional photoelectric deflection instrument, and the steering engine drives the photoelectric deflection instrument to rotate, the rotation angle of the steering engine can be obtained through the position encoder, the left and right sides of the photoelectric deflection instrument are switched to two or more fixed positions, and the reference target of a specific shape (such as a triangle) can be photographed each time the position is switched. After switching to the corresponding position each time, the relative position change of the several measurement targets and the reference target in the picture can be calculated, and the switching and data acquisition are sequentially performed, so that the measurement targets and the reference targets at different angles are realized, and one photoelectric deflection instrument can monitor the deformation data of a large range of measurement targets. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is a system block diagram of the acquisition system; Figure 2 It is a photoelectric deflection instrument rotation diagram of the acquisition system; Figure 3 It is a photoelectric deflection instrument rotation diagram of the acquisition system.

[0011] In the figure: 1, measuring point target, 2, reference target, 3, measuring point target, 4, photoelectric deflection instrument, 5, steering engine, 6, RJ45 interface line, 7, RS485 communication line, 8, control system. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with specific examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0013] Example 1

[0014] The time-sharing multiplexing acquisition mode is adopted, and the reference target and the measuring point target feature shape are automatically distinguished, and the relative displacement change is calculated by itself. Therefore, the design has the components of the industrial computer or the gateway controller, realizes the photoelectric deflection instrument data acquisition, the target shape recognition, the control of the steering engine and the acquisition of the steering angle position of the steering engine.

[0015] In order to realize the switching of the rotation angle, the photoelectric deflection instrument bottom is designed with a rotary steering engine with a position encoder, which realizes the rotation of the horizontal plane of the photoelectric deflection instrument. The steering engine has a position encoder, which controls the rotation and position reporting through RS485. The host computer or the control system can send a rotation instruction, and the encoder data reported by the steering engine. When rotating to the set position, the host computer or the control system sends a stop rotation instruction.

[0016] The present application switches the measuring targets of different angles by the steering engine rotation mode. The reference target is placed in the center position of the system during actual installation, and a special shaped target (the reference target is a triangle) is used for distinguishing. The measuring point target adopts a circle shape as the distinguishing feature. The system automatically distinguishes whether it is a reference target or a measuring point target through the imaging characteristics of the target, and can also be configured manually to select the properties of the measuring point, whether it is a measuring point target or a reference target.

[0017] During on-site installation, the reference target needs to be designed in the middle position of the system to minimize the cumulative error, or multiple reference targets can be used. During the first imaging test, the appropriate angle needs to be adjusted to minimize the number of rotations to collect the data of all measuring points and reference points. After adjusting several shooting angles, the position encoder data of the steering engine is collected and recorded, and is set in the host computer software as the point position information for automatic inspection of the system.

[0018] When the system is working, the photoelectric deflection instrument respectively collects deflection settlement data of the targets on the left and right sides of the installation position, and the positions of the measurement targets 1-N in the image at the current time (X1, Y1), (X2, Y2)... (Xn, Yn) can be obtained, the position of the reference target in the image is (Xbase, Ybase), and the horizontal change data of each measurement point relative to the reference point is X1-Xbase, X2-Xbase... Xn-Xbase, and the vertical change data of each measurement point relative to the reference point is Y1-Ybase, Y2-Ybase... Yn-Ybase.

[0019] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacements or changes according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for expanding the field of view of a photoelectric deflectometer, characterized by: The specific steps of the method for expanding the field of view angle of the photoelectric deflectometer are as follows: Step 1: Install a rotary servo. A rotary servo with a position encoder is designed at the bottom of the photoelectric deflectometer to achieve horizontal rotation of the photoelectric deflectometer. Step 2: Interconnect the servo with the control system. The servo has a position encoder that controls rotation and reports position via the RS485 communication line. The control system can send rotation commands via the RJ45 interface line. Based on the encoder data reported by the servo, when the servo rotates to the set position, the control system issues a stop rotation command. Step 3: Use the servo to rotate and switch the measurement targets at different angles. The reference target is placed in the center of the system during actual installation and is distinguished by a special shape. The reference target is △, and the measurement point target is ○-shaped. The system automatically distinguishes whether it is a reference target or a measurement point target based on the characteristics of the target imaging. Step 4: Data acquisition. When the system is working, the photoelectric deflectometer collects deflection settlement data of the targets on the left and right sides of the installation position respectively. The positions of the measurement targets 1-N in the image at the current time can be obtained (X1, Y1), (X2, Y2)...(Xn, Yn). The position of the reference target in the image is (Xbase, Ybase). The horizontal change data of each measuring point relative to the reference point is X1-Xbase, X2-Xbase...Xn-Xbase, and the vertical change data of each measuring point relative to the reference point is Y1-Ybase, Y2-Ybase...Yn-Ybase decomposition, thereby completing the measurement work of the photoelectric deflectometer.

2. The method for expanding the field of view of a photoelectric deflectometer according to claim 1, wherein: During on-site installation, the basic target needs to be designed in the middle position of the system to reduce cumulative errors. Multiple reference targets can also be used. During the first imaging test, it is necessary to adjust the appropriate angle and rotate as few times as possible to collect data from all measuring points and reference points. After adjusting several shooting angles, the data from the servo position encoder is collected, recorded, and set in the host computer software as the point position information for the system's automatic inspection.

3. The method for expanding the field of view of a photoelectric deflectometer according to claim 1, wherein: The data collection adopts a time-division multiplexing collection method.

4. The method for expanding the field of view of a photoelectric deflectometer according to claim 1, wherein: Targets can also be distinguished through manual configuration, selecting the properties of the measuring point, whether it is a measuring point target or a reference target.

5. The method for expanding the field of view of a photoelectric deflectometer according to claim 1, wherein: The control system is an industrial computer or a gateway controller.

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