CN101718536B - Triangular diamond tool angle high-precision automatic measurement system and measurement method - Google Patents

Abstract

The invention relates to a high-precision automatic measurement system for the angle of a diamond tool and a method for measuring the angle of a triangular diamond tool by using the system. The automatic measurement system includes: a base, a lifting platform fixed on the base, an image acquisition device, an acquisition card, and a controller and a computer; use the computer to carry out rotation control, extract the contour lines on both sides of the tool in the contour image in real time, find the angle between the two lines, and make the tool rotate to the maximum and minimum measurement positions of the angle, so as to determine the maximum angle of the tool The optimal measurement position, the angle between the two straight lines obtained at the optimal measurement position is the tool angle.

Description

Triangular diamond tool angle high-precision automatic measurement system and measurement method

technical field

The invention belongs to the technical fields of ultra-precision machining, computer vision detection and image testing, and relates to a high-precision automatic measurement system for the angle of a triangular diamond tool.

Background technique

Diamond tools are the main tool for ultra-precision cutting. They have good wear resistance, hardness and thermal conductivity, and can be used for single cutting of non-ferrous metals to achieve nano-level roughness surface processing. The triangular diamond tool is an important tool for processing microstructures such as microgrooves and microprisms. Since the microstructure is directly copied on the workpiece by the shape of the tool, the accuracy of the tool parameters is an important indicator to ensure the processing of the microstructure. The very important parameter for the triangular diamond tool is the tool angle. At present, the methods for measuring the angle mainly include non-contact optical methods such as universal tool microscope, super depth-of-field microscope, and measurement projector. , there is an error in the measured angle, which leads to the problem that the measured value is different every time. In addition, the existing methods mainly rely on manually selecting the outer contour of the tool for measurement, which will inevitably introduce human error. In view of the importance of tool parameters and the shortcomings of measurement, it is necessary to develop a high-precision automatic measurement system for diamond tool angles.

Contents of the invention

The invention proposes a high-precision automatic measurement system for the angle of a diamond tool, which can automatically optimize and adjust the position of the measuring tool to determine the best measurement position, thereby realizing high-precision measurement of tool parameters. For this reason, the present invention adopts following technical scheme:

A high-precision automatic measurement system for the angle of a triangular diamond tool, comprising: a base, a lifting platform fixed on the base, an image acquisition device, an acquisition card, a controller and a computer, characterized in that a translation platform is arranged on the base, and the An angle stage and a rotation stage are stacked on the translation platform in sequence. The rotation axis of the angle stage is perpendicular to the axis of the lifting platform and the optical axis of the image acquisition device. Orthogonal, the workpiece fixture for clamping the triangular diamond tool holder to be measured is fixed on the rotary table; the image acquisition device includes a backlight plate, a lens, and a camera fixed on the lifting platform through a bracket, and the fixture is located on the backlight Between the board and the lens, the profile image of the triangular diamond tool to be measured collected by the acquisition card is sent to the computer, and the controller is connected to the computer, the rotary table and the angle table respectively, and is used to control the rotary table and the angle table according to the instructions sent by the computer. For the movement of the angle stage, the computer calculates according to the contour image, and controls the movement of the rotary table and the angle stage through the controller to search for the best measurement position of the tool angle, and calculates the tool angle.

The present invention simultaneously provides a method for measuring the angle of a triangular diamond tool using the above-mentioned automatic measuring system, comprising the following steps:

(1) Fix the triangular diamond tool and the tool holder to be tested on the fixture, so that the rake face faces the lens and faces away from the backlight;

(2) Adjust the translation platform and the lifting platform so that the image acquisition device can clearly collect the outline of the triangular diamond tool to be measured;

(3) Utilize the image acquisition device to collect the contour image of the cutting tool, and send it into the computer;

(4) Perform optimization and adjustment in the following way to determine the best measurement position of the tool angle: first, use the computer to control the rotation of the turntable through the controller, extract the contour lines on both sides of the tool in the contour image in real time during the rotation process, and solve The angle between the two straight lines is adjusted according to the angle, so that the tool rotates to the maximum measurement position of the angle; then the computer is used to control the rotation of the angle table through the controller, and the two sides of the tool in the contour image are extracted in real time during the rotation process. The contour line of the side, solve the angle between two straight lines, adjust the angle table according to the angle, make the tool rotate to the minimum measurement position of the angle, so as to determine the best measurement position of the tool angle;

(5) The angle between the two straight lines obtained by solving the best measurement position is the tool angle.

The present invention uses a backlight panel that projects parallel light to project light from the back of the tool. The light is blocked by the tool and becomes a black image in the camera, while other areas are white, which can highlight the tool profile. The tool can be accurately and real-time acquired by means of a high-precision profile extraction algorithm. Contour information for accurate calculation of tool angles. Control the micro-movement of the rotary table and the angle table, automatically judge the positional relationship between the tool and the lens according to the change trend of the measured tool angle, and perform micro-adjustment of the rotary table and the angle table. Since it is completely used as an electronic control platform, it can automatically find the tool Optimal measurement position. Therefore, the present invention has the characteristics of high precision, high efficiency and complete automation.

Description of drawings

Figure 1 System structure diagram.

Figure 2 Front view of the tool platform.

Figure 3 Diamond cutter profile.

Figure 4. Motion control strategy for a rotary table.

Figure 5. Motion control strategy for the corner stage.

The reference signs are explained as follows:

1 base 2 lifting tables 3 brackets 4 translation stages 5 corner table 6 rotating tables 7 Fixtures 8 backlight panels 9 lenses 10 cameras 11 controllers 12 computers

Detailed ways

The system structure of the present invention is shown in Figure 1. The backlight panel, magnifying lens and camera are fixed on the same support to form the overall structure of the collection device and placed on the lifting platform. The optical axis of the collection device is perpendicular to the axial direction of the lifting platform. The focal length and magnification of the magnifying lens are fixed, so its focusing distance and depth of field range are also determined. A translation platform that can be moved in a small amount is placed on the base of the system, which can perform bidirectional movement from the backlight panel to the lens. The movement axis is parallel to the acquisition device and perpendicular to the axis of the lifting platform. Stack the angle stage and the rotation stage on the translation platform in sequence. The rotation axis of the angle stage is perpendicular to the axis of the lifting platform and the optical axis of the acquisition device. The axis of the rotation stage is parallel to the axis of the lifting platform and positive to the rotation axis of the angle stage. pay. The tool holder and diamond tool holder are fixed on the rotating table and are coaxial with the rotating shaft. The initial position of the translation stage needs to ensure that the tool is within the focus range of the acquisition device, and the degree of focus can be adjusted by the micro-movement of the translation stage. The height of the rotary table, fixture and tool holder is guaranteed to be within the radius of gyration (R) of the angle table, and the overall height is guaranteed to be slightly above the rotation axis of the angle table after the diamond tool is installed, as shown in Figure 2.

After the above assembly and adjustment, install the diamond tool on the tool holder, with the rake face facing the camera and back to the backlight, adjust the translation stage slightly, and collect a clear outline image of the triangular diamond tool, as shown in Figure 3. Through image preprocessing and sub-pixel extraction algorithm, the contour lines on both sides of the tool can be accurately extracted, the data of the contour lines on both sides are fitted with straight lines, and the angle value of the tool at the current position can be obtained by solving the angle between the two straight lines.

Optimally adjust the tool according to the following method to determine the best measurement position. First, use the computer to send instructions to the controller to control the rotation of the rotary table, rotate the rotary table in a small amount, calculate the tool angle in real time during the rotation process, and determine the current best position according to the change law of the measured tool angle. The specific movement The control strategy is shown in Figure 4, rotate to the maximum measurement position of the tool angle. Then, use the computer to send instructions to the controller to control the rotation of the angle table, rotate the angle table in a small amount, and calculate the tool angle in real time during the rotation process, and control the turn table according to the motion control strategy shown in Figure 5. Go to the minimum measurement position of the tool angle, that is, the best measurement position, so as to obtain the precise value of the tool angle.

Claims (2)

1. A high-precision automatic measurement system for the angle of a triangular diamond tool, comprising: a base, a lifting platform fixed on the base, an image acquisition device, an acquisition card, a controller and a computer, and it is characterized in that the base is provided with a translation platform , an angle stage and a rotation stage are stacked sequentially on the translation stage, the rotation axis of the angle stage is perpendicular to the axis of the lifting platform and the optical axis of the image acquisition device, the axis of the rotation stage is parallel to the axis of the lifting platform, and is parallel to the axis of the angle stage The rotation axis is orthogonal, and the tooling fixture for clamping the triangular diamond tool holder to be measured is fixed on the rotating table; the image acquisition device includes a backlight plate, a lens and a camera fixed on the lifting platform by a bracket, and the tooling fixture Located between the backlight plate and the lens, the profile image of the triangular diamond tool to be measured collected by the acquisition card is sent to the computer, and the controller is connected to the computer, the rotary table and the angle table respectively, and is used to control the rotation according to the instructions sent by the computer The movement of the table and the angle table, the computer determines the best measurement position of the tool angle according to the following method: first, use the computer to control the rotation of the rotary table through the controller, and extract the two sides of the tool in the contour image in real time during the rotation process. The contour line of the side, solve the angle between two straight lines, adjust the rotary table according to the angle, so that the tool rotates to the maximum measurement position of the angle; then use the computer to control the rotation of the angle table through the controller, in real time during the rotation Extract the contour lines on both sides of the tool in the contour image, solve the angle between the two lines, adjust the angle table according to the angle, make the tool rotate to the minimum measurement position of the angle, determine the best measurement position of the tool angle, and The angle between the two straight lines obtained by solving the optimal measurement position is obtained to obtain the tool angle. 2. a method adopting the automatic measuring system claimed in claim 1 to measure the angle of the triangular diamond tool comprises the following steps: (1) Fix the triangular diamond tool and the tool holder to be tested on the fixture, so that the rake face faces the lens and faces away from the backlight; (2) Adjust the translation platform and the lifting platform so that the image acquisition device can clearly collect the outline of the triangular diamond tool to be measured; (3) Utilize the image acquisition device to collect the contour image of the cutting tool, and send it into the computer; (4) Perform optimization and adjustment in the following way to determine the best measurement position of the tool angle: first, use the computer to control the rotation of the turntable through the controller, extract the contour lines on both sides of the tool in the contour image in real time during the rotation process, and solve The angle between the two straight lines is adjusted according to the angle, so that the tool rotates to the maximum measurement position of the angle; then the computer is used to control the rotation of the angle table through the controller, and the two sides of the tool in the contour image are extracted in real time during the rotation process. The contour line of the side, solve the angle between two straight lines, adjust the angle table according to the angle, make the tool rotate to the minimum measurement position of the angle, so as to determine the best measurement position of the tool angle; (5) The angle between the two straight lines obtained by solving the best measurement position is the tool angle.

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