Method and system for measuring vibration deformation of robot drilling system

Abstract

The invention provides a vibration deformation measurement method and system for a robot hole making system, and belongs to the technical field of intelligent equipment.The method comprises the steps that a binocular measurement system is adopted to continuously shoot and record feature identification points on the surfaces of a robot mechanical arm, a hole making tail end executor and a tool; performing hole making operation on the hole making object; calculating a three-dimensional coordinate of each feature identification point in the feature identification point image at each moment; by taking the three-dimensional coordinates at a certain moment before drilling as a reference, calculating three-dimensional displacements of a robot mechanical arm, a drilling end effector and a tool in the drilling process to obtain vibration deformation data of the robot mechanical arm, the drilling end effector and the tool in the drilling process; the problems of overlarge amplitude, abnormal frequency and the like of the equipment can be found in time, and the equipment stability and the drilling quality are guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent equipment, and in particular relates to a vibration deformation measurement method and system for a robot hole making system. Background Art

[0002] Hole making is a critical process in the aviation field. Its quality and accuracy directly affect the safety and performance of aircraft. Automated robotic hole making equipment can improve hole making quality and efficiency, and its position is becoming increasingly important.

[0003] However, during the operation of the robotic hole-making equipment, due to the combined effects of factors such as spindle rotation, tool cutting friction and clamping force, the robotic arm, hole-making end effector and product clamping tooling often vibrate and deform, which can easily lead to problems such as hole eccentricity, inaccurate hole diameter and unstable hole-making quality.

[0004] Therefore, it is necessary to provide a vibration deformation measurement method for monitoring the robotic hole-making equipment, so as to promptly detect problems such as excessive amplitude and abnormal frequency in the equipment, thereby ensuring the stability of the equipment and the quality of hole-making. Summary of the invention

[0005] In order to solve the problems of vibration deformation of robot hole-making equipment in the prior art during the hole-making process, resulting in hole eccentricity, inaccurate hole diameter, unstable hole-making quality, etc., the present invention provides a vibration deformation measurement method and system for a robot hole-making system based on binocular vision. The characteristic identification points attached to the robot, the hole-making end effector and the tooling are photographed and recorded by a binocular camera, and the real-time three-dimensional coordinates of each identification point are calculated according to the binocular vision algorithm to obtain the vibration data of the robot and the end effector and the three-dimensional deformation data of the tooling during the hole-making process. The technical solution is as follows:

[0006] In a first aspect, a method for measuring vibration deformation of a robot hole making system is provided, the method comprising:

[0007] Step 1: Set the binocular measurement system next to the robot hole making system, adjust the postures of the two imaging devices, and adjust the shooting parameters so that clear images of the robot mechanical arm, the hole making end effector and the tooling can be presented in the field of view of the two imaging devices; the robot hole making system includes the robot mechanical arm, the hole making end effector and the tooling;

[0008] Step 2: Place the calibration plate within the overlapping field of view of the two imaging devices, and trigger the imaging device to shoot the calibration plate; after the image is stored, move the calibration plate to the next posture and shoot and store the image of the calibration plate, repeat this step until more than 9 calibration plate images in postures are stored;

[0009] Step 3: Use a binocular measurement system to continuously shoot and record the characteristic identification points on the robot arm, the hole-making end effector, and the tooling surface;

[0010] Step 4, performing hole making operation on the hole making object;

[0011] Step 5, calculating the three-dimensional coordinates of each feature identification point in the feature identification point image at each moment;

[0012] Step six, based on the three-dimensional coordinates at a certain time before hole making, calculate the three-dimensional displacement of the robot manipulator, hole making end effector and tooling during the hole making process, and obtain the vibration deformation data of the robot manipulator, hole making end effector and tooling during the hole making process.

[0013] The shooting parameters in step 1 include the camera field of view, focal length and exposure parameters; the binocular measurement system independently controls the spatial position, shooting angle and imaging parameters of the two imaging devices.

[0014] Among them, in step 2, in order to more accurately calculate the internal and external parameter matrices of the two imaging devices, the size of the calibration plate is 1 / 4 to 1 / 3 of the field of view size of the imaging device; the calibration plate is placed in a position where the two imaging devices can form an overlapping field of view and where clear imaging can be achieved; the calibration plate is placed in the lower left, lower middle, lower right, left, middle, right, upper left, upper middle, and upper right positions of the overlapping area.

[0015] Among them, the feature identification points used for visual measurement set on the robot arm, the hole-making end effector and the tooling surface are reflective markings with coded points, or marking points with random geometric features.

[0016] Optionally, the feature identification points are fixed to the robot arm, the hole-making end effector and the tooling surface by pasting, painting or spraying.

[0017] Among them, in step three, the binocular measurement system controls two imaging devices to capture and record the feature identification point images of the shooting object at the same time. The shooting time covers the entire hole making process, so as to accurately obtain the vibration deformation data of the hole making end effector and the product clamping tooling during the hole making process.

[0018] Optionally, step five specifically includes:

[0019] According to the calibration plate images in various postures captured by the binocular camera, the internal and external parameter matrices of the two imaging devices are calculated;

[0020] According to the internal and external parameter matrix and the feature identification point images under two viewing angles, the three-dimensional coordinates of each feature identification point before and after hole making are calculated, and its coordinate system is fixed on the left camera coordinates.

[0021] Among them, in step six, the three-dimensional displacement of the robot arm, the end effector and the tooling is obtained by subtracting the three-dimensional coordinates of the feature identification points at two moments.

[0022] In a second aspect, a vibration deformation measurement system of a robot hole making system is provided, which is applied to any vibration deformation measurement method of a robot hole making system described in the first aspect, and the system comprises: a binocular measurement system and a robot hole making system,

[0023] A binocular measurement system can include two imaging devices, a tripod,

[0024] The robotic hole-making system includes a robotic arm, a hole-making end effector and a tooling.

[0025] The beneficial effects of the present invention are at least:

[0026] A binocular measurement system is used to continuously capture and record the characteristic identification points on the robot arm, hole-making end effector and tooling surface; hole-making operations are performed on the hole-making object; the three-dimensional coordinates of each characteristic identification point in the characteristic identification point image at each moment are calculated; based on the three-dimensional coordinates at a certain moment before hole-making, the three-dimensional displacement of the robot arm, hole-making end effector and tooling during the hole-making process is calculated, and the vibration deformation data of the robot arm, hole-making end effector and tooling during the hole-making process is obtained; problems such as excessive amplitude and abnormal frequency of the equipment can be discovered in time to ensure equipment stability and hole-making quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an application scenario of a binocular measurement system in which two tripods are independently placed according to the present invention;

[0028] Figure 2 This is an application scenario of a binocular measurement system placed on a tripod of the present invention;

[0029] Figure 3 It is a characteristic identification point pasted on the hole-making end effector of the present invention and the product clamping tooling;

[0030] Figure 4 The dual purpose of the present invention is to achieve the desired results;

[0031] Figure 5 The measurement results of the marking points of the end effector and the product clamping tooling before and after the hole making of the present invention;

[0032] Figure 6 The vibration deformation data of the end effector and the product clamping tooling during the hole making process of the present invention;

[0033] Figure 7 The present invention is a flow chart of a method for measuring vibration deformation of a robot hole-making system based on binocular vision. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below through specific implementation modes and drawings.

[0035] See also Figure 7 An embodiment of the present invention provides a vibration deformation measurement method for a robot hole making system, comprising the following steps:

[0036] Step 1: Set the binocular measurement system next to the robot hole making system, adjust the postures of the two imaging devices, and adjust the camera field of view, focal length, exposure and other shooting parameters so that the field of view of the two imaging devices can present clear images of the robot arm, hole making end effector and tooling;

[0037] In one implementation, the binocular measurement system may include two imaging devices, a tripod,

[0038] The robotic hole-making system includes a robotic arm, a hole-making end effector and a tooling.

[0039] On the one hand, if Figure 1 As shown in FIG. 1 , the binocular measurement system can be in the form of two tripods independently supporting respective imaging devices. Figure 2 As shown, the binocular measurement system can be in the form of a tripod supporting two imaging devices at the same time. The specific support form can be selected and determined according to the actual situation on site, and the embodiment of the present invention does not limit this.

[0040] The binocular measurement system can independently control the spatial position, shooting angle and imaging parameters of the two imaging devices, including light intensity, focal length, aperture, shooting frame number, exposure time, simultaneous triggering and other imaging parameters, so as to achieve clear imaging of the end effector of hole making, product clamping tooling and other shooting objects in the field of view. The control process can refer to the relevant technology.

[0041] Step 2: Place the calibration plate in the overlapping field of view of the two imaging devices, and trigger the imaging device to shoot the calibration plate. After the image is stored, move the calibration plate to the next posture and shoot and store the image of the calibration plate. Repeat this step until more than 9 (usually more than 9 and less than or equal to 14) calibration plate images in postures are stored;

[0042] In order to more accurately calculate the intrinsic and extrinsic parameter matrices of the two imaging devices, in the embodiment of the present invention, the size and setting position of the calibration plate can be designed as follows:

[0043] The size of the calibration plate should be between 1 / 4 and 1 / 3 of the field of view of the imaging device.

[0044] The calibration plate needs to be placed in a position where the fields of view of the two imaging devices overlap and where clear images can be obtained.

[0045] The calibration plate should be placed in the lower left, lower center, lower right, left, center, right, upper left, upper center, and upper right positions of the overlapping area as much as possible.

[0046] Step 3: Follow Figure 3 As shown, feature identification points used for visual measurement are set on the robot arm, the hole-making end effector and the tooling surface;

[0047] In one possible implementation, feature identification points used for visual measurement are made on the robot arm, the hole-making end effector, and the surface of the tooling, and may be reflective identification points with coded points.

[0048] In another possible implementation, feature identification points used for visual measurement are made on the robot arm, the hole-making end effector and the surface of the tooling, and the feature identification points may be identification points with random geometric features such as speckle.

[0049] For example, the feature identification points can be fixed on the end effector and the product tooling surface by sticking, painting, spraying, etc.

[0050] Since step one can ensure that clear images of the robot arm, hole-making end effector and tooling can be presented in the field of view of both imaging devices, there is no need to limit the setting positions of the feature identification points on the robot arm, hole-making end effector and tooling surface.

[0051] Step 4: Execute the binocular measurement program to continuously shoot and record the feature identification points;

[0052] The binocular measurement system can control two imaging devices to capture and record feature point images of the object at the same time. The shooting time can cover the entire hole-making process, so as to accurately obtain the vibration deformation data of the hole-making end effector and the product clamping tooling during the hole-making process.

[0053] Step 5, executing the hole making program to perform hole making operation on the hole making object;

[0054] The specific process of hole making operation can refer to relevant technology and will not be described in detail here.

[0055] Step 6, calculating the three-dimensional coordinates of each feature identification point in the feature identification point image at each moment according to the binocular vision calculation program;

[0056] The binocular vision calculation program can calibrate the internal and external parameters of the binocular measurement system based on the images of the calibration plate at different positions.

[0057] The binocular vision computing program can identify and locate feature identification points based on the digital images recorded by two imaging devices at the same time from two perspectives, and calculate the three-dimensional coordinates of the feature identification points based on the image coordinate information of the feature identification points from the two perspectives in combination with the calibrated internal and external parameter matrices. The specific process of calculating the three-dimensional coordinates of the feature identification points in combination with the calibrated internal and external parameter matrices can be referred to the relevant technology.

[0058] The binocular vision calculation program obtains the three-dimensional coordinates of the feature identification point, and its coordinate system can be set as a camera coordinate system with the optical center of the imaging device as the origin and the optical axis of the lens as the coordinate axis; it can also be set as a coordinate system with a certain point on the tooling as the origin and fixed on the tooling.

[0059] In one achievable manner, step six may specifically include the following steps:

[0060] 1. Based on the calibration plate images in various postures captured by the binocular camera, the calibration program is called to calculate the internal and external parameter matrices of the two imaging devices. The calculation results are as follows: Figure 4 shown.

[0061] 2. According to the internal and external parameter matrix and the feature identification point images under two viewing angles, the three-dimensional coordinates of each feature identification point before and after hole making are calculated. The coordinate system is fixed on the left camera coordinate system, as shown in the following figure: Figure 5 The calculation results are shown.

[0062] Step 7: Based on the three-dimensional coordinates at a certain time before hole making, the three-dimensional displacements of the robot, hole making end effector and tooling during the hole making process are calculated to obtain the vibration deformation data of the robot arm, hole making end effector and product clamping tooling during the hole making process, such as Figure 6 shown.

[0063] The three-dimensional displacement of the robot arm, end effector and tooling is obtained by subtracting the three-dimensional coordinates of the feature identification points at two moments. The three-dimensional coordinates of the robot arm, end effector and the feature identification points on the tooling surface before hole making are taken as the initial values. After subtracting the initial values ​​from the three-dimensional coordinates of the feature identification points obtained during the hole making process, the vibration deformation information during the hole making process can be obtained.

[0064] Another embodiment of the present invention further provides a vibration deformation measurement system for a robot hole making system, which is applied to the vibration deformation measurement method for a robot hole making system described in the method embodiment of the present invention. The system includes: a binocular measurement system and a robot hole making system, such as Figure 1 , Figure 2 shown.

[0065] The binocular measurement system may include two imaging devices and a tripod. The binocular measurement system may be in the form of two tripods independently supporting respective imaging devices, or in the form of one tripod supporting two imaging devices simultaneously.

[0066] The robotic hole-making system includes a robotic arm, a hole-making end effector and a tooling.

[0067] The above only expresses the implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. In addition, the parts not detailed in the present invention are all conventional technologies.

Claims

1. A method for measuring vibration deformation of a robot hole making system, characterized in that: The method comprises: Step 1: Set the binocular measurement system next to the robot hole making system, adjust the postures of the two imaging devices, and adjust the shooting parameters so that clear images of the robot mechanical arm, the hole making end effector and the tooling can be presented in the field of view of the two imaging devices; the robot hole making system includes the robot mechanical arm, the hole making end effector and the tooling; Step 2: Place the calibration plate within the overlapping field of view of the two imaging devices, and trigger the imaging device to shoot the calibration plate; after the image is stored, move the calibration plate to the next posture and shoot and store the image of the calibration plate, repeat this step until more than 9 calibration plate images in postures are stored; Step 3: Use a binocular measurement system to continuously shoot and record the characteristic identification points on the robot arm, the hole-making end effector, and the tooling surface; Step 4, performing hole making operation on the hole making object; Step 5, calculating the three-dimensional coordinates of each feature identification point in the feature identification point image at each moment; Step six, based on the three-dimensional coordinates at a certain time before hole making, calculate the three-dimensional displacement of the robot manipulator, hole making end effector and tooling during the hole making process, and obtain the vibration deformation data of the robot manipulator, hole making end effector and tooling during the hole making process.

2. The method according to claim 1, characterized in that The shooting parameters in step one include the camera field of view, focal length and exposure parameters; the binocular measurement system independently controls the spatial position, shooting angle and imaging parameters of the two imaging devices.

3. The method according to claim 1, characterized in that In step 2, the size of the calibration plate is between 1 / 4 and 1 / 3 of the field of view of the imaging device; the calibration plate is placed in a position where the fields of view of the two imaging devices overlap and where clear imaging can be achieved; the calibration plate is placed in the lower left, lower middle, lower right, left, middle, right, upper left, upper middle, and upper right positions of the overlapping area.

4. The method according to claim 1, characterized in that: The feature identification points used for visual measurement set on the robot manipulator, hole-making end effector and tooling surface are reflective markings with coded points, or marking points with random geometric features.

5. The method according to claim 4, characterized in that The feature identification points are fixed on the robot arm, hole-making end effector and tooling surface by pasting, painting or spraying.

6. The method according to claim 1, characterized in that In step three, the binocular measurement system controls two imaging devices to simultaneously capture and record feature identification point images of the object, and the shooting time covers the entire hole making process.

7. The method according to claim 1, characterized in that Step 5 specifically includes: According to the calibration plate images in various postures captured by the binocular camera, the internal and external parameter matrices of the two imaging devices are calculated; According to the internal and external parameter matrix and the feature identification point images under two viewing angles, the three-dimensional coordinates of each feature identification point before and after hole making are calculated, and its coordinate system is fixed on the left camera coordinates.

8. The method according to claim 1, characterized in that: In step six, the three-dimensional displacement of the robot arm, the end effector and the tooling is obtained by subtracting the three-dimensional coordinates of the feature identification points at two moments.

9. A vibration deformation measurement system for a robot hole making system, characterized in that: The vibration deformation measurement method for a robot hole making system according to any one of claims 1 to 8, wherein the system comprises: a binocular measurement system and a robot hole making system, A binocular measurement system can include two imaging devices, a tripod, The robotic hole-making system includes a robotic arm, a hole-making end effector and a tooling.

Images