An automatic RTCP calibration method

Abstract

This invention relates to the field of RTCP calibration technology and discloses an automatic RTCP calibration method, comprising the following steps: controlling the tool rotation device of a CNC machine tool to rotate at a reference point; acquiring images of the tool rotation device at various rotation angles using a camera device to obtain image data sets; comparing these images with reference images of the tool rotation device at various rotation angles in the CNC machine tool database; analyzing the deviation value of the tool rotation device and generating a compensation value based on the deviation value; and inputting the compensation value to the data machine tool to adjust the position of the tool rotation device. This invention uses a camera device to acquire images of the tool rotation device at various rotation angles and compares them with the original images for RTCP calibration. Compared to existing technologies, this error detection method is more convenient and direct, effectively improving the speed and accuracy of the calibration process.

Description

Technical Field

[0001] This invention relates to the field of RTCP calibration technology, and in particular to an automatic RTCP calibration method. Background Technology

[0002] The RTCP (Rotation Tool Center Point) function is a commonly used function in 5-axis systems, providing tool tip tracking. The 5-axis system keeps the tool center at its programmed XYZ position. To maintain this position, every rotational movement is compensated by a linear displacement in the XYZ coordinates, ensuring the tool center remains in the same location.

[0003] For example, an existing patent (publication number CN 116047997 B) discloses an RTCP compensation method and device for a CNC machine tool, comprising: controlling the rotation axis of the CNC machine tool to rotate by an angle; determining the error compensation amount caused by rotating the rotation axis based on the angle and the rotation axis vector corresponding to the rotation axis, wherein the rotation axis vector is the unit vector of the rotation axis of the CNC machine tool; and compensating the error value caused by rotating the rotation axis based on the error compensation amount, so as to compensate for the RTCP motion of the CNC machine tool. This invention addresses the deficiency in the prior art where RTCP calculation is not accurate enough, resulting in poor RTCP motion accuracy, and improves the RTCP motion accuracy.

[0004] The inventors discovered that current RTCP calibration still uses a contact measurement method with probes or other measuring devices. After measuring the results, the results are then input into the CNC system. However, this method is quite cumbersome. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art by proposing an automatic RTCP calibration method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An automatic RTCP calibration method includes the following steps:

[0008] The tool rotation device of a CNC machine tool rotates at a reference point.

[0009] Images of the cutting tool rotating device at various rotation angles are acquired using a camera device to obtain image data sets;

[0010] Compare with reference images of various rotation angles of the tool rotation device in the CNC machine tool database;

[0011] Analyze the deviation values ​​of the tool rotation device and generate compensation values ​​based on the deviation values;

[0012] Input the compensation value into the data machine tool and adjust the position of the tool rotation device.

[0013] Preferably, the camera device is a monitoring camera used in the processing area, which is connected to a camera position control device and is installed above the CNC machine tool.

[0014] Preferably, the specific process of acquiring images of each rotation angle of the tool rotating device is as follows: the camera device is moved to a horizontal position with the center of the tool rotating device, and the entire rotation process of the tool rotating device is acquired by recording video. The rotation time of each degree of the tool rotating device is adapted to the frame rate of the camera device.

[0015] Preferably, the reference points include preset reference points and additional accident reference points.

[0016] Preferably, the method for adding the accident reference point is as follows: vibration sensors are installed at multiple locations on the CNC machine tool to detect the vibration level of the machine tool. Based on the vibration level, it is determined whether the CNC machine tool has been impacted, as well as the time and location of the impact. If it is determined that an impact has occurred, the position of the corresponding tool rotation device at that location is added as the accident reference point.

[0017] Preferably, when the CNC machine tool is impacted, an alarm is triggered to the staff. The staff determines whether the CNC machine tool needs maintenance. If no maintenance is needed, the tool rotation device is moved to the reference point for calibration.

[0018] Preferably, the RTCP calibration method further includes monitoring the environment in which the CNC machine tool is located, and automatically performing the calibration process when the environment changes.

[0019] Preferably, the environmental monitoring specifically includes monitoring temperature, humidity, and the position of the CNC machine tool.

[0020] Preferably, when acquiring images of each rotation angle of the tool rotating device through the camera device, the method further includes scanning the tool rotating device with an optical scanner to measure the three-dimensional contour of the object surface, thereby improving the accuracy of error analysis.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This invention uses a camera device to acquire images of the tool rotation device at various rotation angles and compares them with the original image to perform RTCP calibration. Compared with existing technologies, this error detection method is more convenient and direct, and can effectively improve the speed and accuracy of the calibration process. Attached Figure Description

[0023] Figure 1 This is a schematic flowchart of an automatic RTCP calibration method proposed in this invention;

[0024] Figure 2 This is a schematic block diagram of the components of an automatic RTCP calibration device proposed in this invention.

[0025] In the diagram: 1. Image acquisition module; 2. Image comparison module; 3. Compensation module. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] Reference Figure 1 An automatic RTCP calibration method includes the following steps:

[0028] S101 controls the tool rotation device of the CNC machine tool to rotate at a reference point;

[0029] S102, acquire images of the tool rotating device at various rotation angles through the camera device to obtain image data sets;

[0030] S103, compare with reference images of various rotation angles of the tool rotation device in the CNC machine tool database;

[0031] S104, Analyze the deviation value of the tool rotation device and generate a compensation value based on the deviation value;

[0032] S105, input the compensation value to the data machine tool and adjust the position of the tool rotation device.

[0033] This method uses a camera to acquire images of the tool rotation device at various rotation angles and compares them with the original images to perform RTCP calibration. Compared with existing technologies, this non-contact error detection method is more convenient and direct, and can effectively improve the speed and accuracy of the calibration process.

[0034] In this embodiment, the camera device is a monitoring camera used in the processing area. This monitoring camera is connected to a camera position control device and is set above the CNC machine tool. Since the processing area already has a camera device, there is no need to configure an additional camera device for this device. When calibration is required, the camera position control device can be used to control the camera device to move down to the detection position. The camera position control device includes a cross electric slide and a push rod motor. The cross electric slide is installed on the ceiling, the push rod motor is installed on the drive end of the cross electric slide, and the camera device is installed on the shaft head of the push rod motor drive shaft. During normal operation, the camera device can be used to monitor the operation of the production line. During calibration, moving it to the detection position can be used to detect and calibrate the tool rotation device.

[0035] In this embodiment, the specific process of acquiring images of each rotation angle of the tool rotating device is as follows: the camera device is moved to a horizontal position with the center of the tool rotating device, and the entire rotation process of the tool rotating device is acquired by recording video. The rotation time of each degree of the tool rotating device is adapted to the frame rate of the camera device. For example, the camera device uses a Phantom VEO 640 high-speed camera. The tool rotating device rotates the tool by 1 degree at a frequency of once per second. The frame rate of the camera device is 1400fps at a resolution of 2560x1600, which can be accurate to less than 1 degree of the tool.

[0036] In this embodiment, the reference points include preset reference points and additional accident reference points. In addition to the preset reference points, CNC machine tools may also be affected by unexpected accidents during use, causing deviations in the position of the tool rotation device. This method takes this situation into account in the calibration method.

[0037] In this embodiment, the method for adding the accident reference point is as follows: vibration sensors are installed at multiple locations on the CNC machine tool to detect the vibration level of the machine tool. Based on the vibration level, it is determined whether the CNC machine tool has been impacted, as well as the time and location of the impact. If it is determined that an impact has occurred, the position of the corresponding tool rotation device at that location is added as the accident reference point. This invention incorporates the collision accident of the CNC machine tool into the calibration method. The collision may cause deformation of the machine tool structure or displacement of components. At the impacted part, the signal value detected by the vibration sensor is relatively large. Therefore, the collision position can be detected by multiple vibration sensors (the detection accuracy of the collision position depends on the number of vibration sensors). When the corresponding position is offset, it is necessary to detect whether the position has shifted. The position of the accident reference point is calculated by taking a picture of the top of the CNC machine tool with a camera device and comparing it with the picture of the preset position. The calculation method is: detecting the horizontal offset and the vertical offset, and determining the position of the accident reference point based on the horizontal offset and the vertical offset.

[0038] In this embodiment, when the CNC machine tool is impacted, an alarm is triggered to the staff. The staff determines whether the CNC machine tool needs repair. If it does not need repair, the tool rotation device is moved to the reference point for calibration. When the CNC machine tool is impacted, it may no longer be able to work and needs repair. Therefore, the staff first determines whether it can continue to work or can work temporarily. If it can work, calibration is then performed.

[0039] In this embodiment, the RTCP calibration method also includes monitoring the environment in which the CNC machine tool is located, and automatically performing the calibration process when the environment changes.

[0040] In this embodiment, the environmental monitoring specifically includes monitoring temperature, humidity, and the position of the CNC machine tool. Significant changes in the environment where the machine tool is located, such as large changes in temperature and humidity, or the machine tool being moved to a new position, may affect the accuracy of the machine tool. In this case, RTCP recalibration needs to be performed. The position is determined by the camera device. Specifically, the camera device moves to a preset position to take a picture of the CNC machine tool and compares it with a preset image to determine whether the position has moved. Temperature and humidity are detected by temperature and humidity sensors, respectively.

[0041] In this embodiment, when acquiring images of each rotation angle of the tool rotating device through the camera device, the method further includes scanning the tool rotating device with an optical scanner to measure the three-dimensional contour of the object surface, thereby improving the accuracy of error analysis.

[0042] Reference Figure 2 An automatic RTCP calibration device, used in an automatic RTCP calibration method, includes:

[0043] Image acquisition module 1 is used to acquire images of the rotation of the tool rotating device at various angles;

[0044] The image comparison module 2 is used to compare the acquired image with reference images of various rotation angles of the tool rotation device in the CNC machine tool database and analyze the error value.

[0045] Compensation module 3 compensates for the error value of the tool rotation device.

[0046] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An automatic RTCP calibration method, characterized in that: Includes the following steps: The tool rotation device of a CNC machine tool rotates at a reference point. Images of the cutting tool rotating device at various rotation angles are acquired using a camera device to obtain image data sets; Compare with reference images of various rotation angles of the tool rotation device in the CNC machine tool database; Analyze the deviation values ​​of the tool rotation device and generate compensation values ​​based on the deviation values; Input the compensation value into the CNC machine tool and adjust the position of the tool rotation device; The reference points include preset reference points and additional accident reference points; The method for adding the accident reference point is as follows: vibration sensors are installed at multiple locations on the CNC machine tool to detect the vibration level of the machine tool. Based on the vibration level, it is determined whether the CNC machine tool has been impacted, as well as the time and location of the impact. If it is determined that an impact has occurred, the position of the corresponding tool rotation device at that location is added as the accident reference point.

2. The automatic RTCP calibration method according to claim 1, characterized in that: The camera device is a monitoring camera used in the processing area. The monitoring camera is connected to a camera position control device and is installed above the CNC machine tool.

3. The automatic RTCP calibration method according to claim 2, characterized in that: The specific process for acquiring images of each rotation angle of the tool rotating device is as follows: the camera device is moved to a horizontal position with the center of the tool rotating device, and the entire rotation process of the tool rotating device is acquired by recording video. The rotation time of each degree of the tool rotating device is adapted to the frame rate of the camera device.

4. The automatic RTCP calibration method according to claim 3, characterized in that: When the CNC machine tool is impacted, an alarm is triggered to the staff. The staff then determine whether the CNC machine tool needs repair. If no repair is needed, the tool rotation device is moved to the reference point for calibration.

5. The automatic RTCP calibration method according to claim 1, characterized in that: The RTCP calibration method also includes monitoring the environment in which the CNC machine tool is located, and automatically performing the calibration process when the environment changes.

6. The automatic RTCP calibration method according to claim 5, characterized in that: The environmental monitoring specifically includes monitoring temperature, humidity, and the position of the CNC machine tool.

7. The automatic RTCP calibration method according to claim 1, characterized in that: When acquiring images of the tool rotating device at various rotation angles using a camera device, the method also includes scanning the tool rotating device with an optical scanner to measure the three-dimensional contour of the object surface, thereby improving the accuracy of error analysis.

8. An automatic RTCP calibration device, applied in an automatic RTCP calibration method according to any one of claims 1-7, characterized in that: include: The image acquisition module is used to acquire images of the rotation of the tool rotating device at various angles. The image comparison module is used to compare the acquired image with reference images of various rotation angles of the tool rotation device in the CNC machine tool database to analyze the error value; The compensation module compensates for errors in the tool rotation device.

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