Grinding wheel morphology measuring device and method

Abstract

The invention discloses a grinding wheel morphology measuring device and method, and relates to the field of grinding wheel in-situ detection of a multi-shaft grinding machine. The device comprises a four-axis linkage mechanism, a line laser sensor, a blowing mechanism and a control measurement module, the four-axis linkage mechanism moves according to the rotation instruction so that the line laser sensor and the air blowing mechanism can move into the set position range of the target grinding wheel; the air blowing mechanism blows air to the surface of the target grinding wheel according to the air blowing instruction; the line laser sensor emits laser according to the laser emission instruction and collects three-dimensional shape data of the target grinding wheel in a set position range; controlling the measurement module to pre-process the three-dimensional morphology data to obtain three-dimensional processed morphology data; performing registration processing on the three-dimensional processed morphology data by adopting an optimized ICP iterative nearest point algorithm and an NDT normal distribution algorithm to obtain overall morphology data; according to the invention, rapid and accurate measurement of the microstructure and the macroscopic size of the grinding wheel can be realized.

Description

Technical Field

[0001] The invention relates to the field of grinding wheel in-situ detection of a multi-axis grinder, and in particular to a grinding wheel profile measuring device and method. Background Art

[0002] Multi-axis grinding technology is widely used in advanced tool manufacturing, optical free-form surface processing and mold manufacturing. The morphology and size of the grinding wheel have an important impact on the performance and reliability of such precision workpieces. Accurate measurement of the morphology and size of the grinding wheel is of great significance to improving the quality and precision of components. At present, traditional contact measurement methods are difficult to quickly measure the three-dimensional morphology of the grinding wheel, and the measurement efficiency is low. In addition, due to the size of the probe, microscopic wear, adhesion and clogging problems on the surface of the grinding wheel are difficult to detect, which can easily lead to grinding burns and deterioration of the surface quality of the workpiece. In view of the difficulty in on-site detection of the grinding wheel morphology and size during multi-axis grinding, it is crucial to achieve rapid and accurate measurement of the microscopic morphology and macroscopic size of the grinding wheel. Summary of the invention

[0003] The purpose of the present invention is to provide a grinding wheel profile measuring device and method, which can realize the rapid and accurate measurement of the microscopic profile and macroscopic size of the grinding wheel.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A grinding wheel profile measuring device, comprising: a four-axis linkage mechanism, a line laser sensor, a blower mechanism, and a control and measurement module;

[0006] The four-axis linkage mechanism, the line laser sensor and the air blowing mechanism are all connected to the control and measurement module;

[0007] The line laser sensor and the air blowing mechanism are arranged on the four-axis linkage mechanism, and the air blowing mechanism is arranged below the line laser sensor;

[0008] The control and measurement module is used to issue control instructions; the control instructions include: rotation instructions, blowing instructions and laser emission instructions;

[0009] The four-axis linkage mechanism is used to move according to the rotation instruction so that the line laser sensor and the air blowing mechanism are moved to a set position range of the target grinding wheel; the set position range is a range from the end surface position to the side surface position;

[0010] The air blowing mechanism is used to perform air blowing treatment on the surface of the target grinding wheel according to the air blowing instruction;

[0011] The line laser sensor is used to emit laser according to the laser emission instruction, and collect three-dimensional shape data of the target grinding wheel within a set position range; the three-dimensional shape data includes: end face shape data and side face shape data; the shape data includes: thickness parameters and surface shape parameters;

[0012] The control and measurement module is also used for:

[0013] Preprocessing the three-dimensional shape data to obtain three-dimensional processed shape data; the preprocessing includes: filtering and noise reduction and interpolation and filling data processing;

[0014] The optimized ICP iterative closest point algorithm and the NDT normal distribution algorithm are used to perform registration processing on the three-dimensional processed morphological data to obtain the overall morphological data.

[0015] Optionally, the four-axis linkage mechanism includes: an X-axis slide, a first swing arm mechanism, a second swing arm mechanism and a Y-axis motion mechanism;

[0016] The X-axis slide and the Y-axis motion mechanism are arranged vertically; one end of the first swing arm mechanism is arranged on the X-axis slide; the other end of the first swing arm mechanism is connected to one end of the second swing arm mechanism;

[0017] The other end of the second swing arm mechanism is arranged on the Y-direction motion mechanism;

[0018] The line laser sensor and the air blowing mechanism are arranged on the Y-direction motion mechanism;

[0019] The X-axis slide table, the first swing arm mechanism, the second swing arm mechanism and the Y-axis motion mechanism are all connected to the control and measurement module.

[0020] Optionally, the X-axis slide table includes: a slide table drive motor, a slide table fixing seat, a slide table lead screw and a first motion support plate;

[0021] The slide fixing seat is arranged on the ground;

[0022] The slide drive motor is connected to the first motion support plate via the slide lead screw; the slide drive motor and the first motion support plate are both arranged on the slide fixing seat;

[0023] The slide drive motor is connected to the control and measurement module.

[0024] Optionally, the first swing arm mechanism comprises: a reducer, a first swing arm motor, a first swing arm and a first swing arm rotating shaft;

[0025] The reducer is arranged on the first moving support plate; the first swing arm motor is arranged above the reducer, and the first swing arm motor is connected to the reducer;

[0026] One end of the first swing arm is arranged above the reducer through the first swing arm rotating shaft; the other end of the first swing arm is connected to one end of the second swing arm mechanism;

[0027] The first swing arm is connected to the first swing arm motor; the first swing arm motor is also connected to the control and measurement module.

[0028] Optionally, the second swing arm mechanism comprises: a second swing arm, a second swing arm motor and a second swing arm rotating shaft;

[0029] One end of the second swing arm is connected to the other end of the first swing arm via the second swing arm rotating shaft;

[0030] The other end of the second swing arm is arranged on the Y-direction motion mechanism;

[0031] The second swing arm motor is arranged above the second swing arm, and the second swing arm motor is connected to the second swing arm; the second swing arm motor is also connected to the control and measurement module.

[0032] Optionally, the distance between the line laser sensor and the measuring surface of the target grinding wheel ranges from 20 mm ± 3 mm.

[0033] A method for measuring grinding wheel profile, the method comprising:

[0034] Acquire three-dimensional topographic data of the target grinding wheel within a set position range; the three-dimensional topographic data includes: end face topographic data and side face topographic data; the topographic data includes: thickness parameters and surface shape parameters;

[0035] Preprocessing the three-dimensional shape data to obtain three-dimensional processed shape data; the preprocessing includes: filtering and noise reduction and interpolation and filling data processing;

[0036] The optimized ICP iterative closest point algorithm and the NDT normal distribution algorithm are used to perform registration processing on the three-dimensional processed morphological data to obtain the overall morphological data.

[0037] Optionally, preprocessing the three-dimensional morphological data to obtain three-dimensional processed morphological data specifically includes:

[0038] Performing interpolation and filling data processing on the three-dimensional shape data to obtain filling data;

[0039] Performing point cloud translation transformation on the filling data to obtain point cloud transformation data;

[0040] Using mean filtering, filtering and fitting processing are performed based on the set threshold vector according to the point cloud transformation data to obtain fitting data;

[0041] The fitting data are corrected by using the least square method to obtain corrected data;

[0042] The correction data is determined as the three-dimensional processed topography data.

[0043] Optionally, an optimized ICP iterative closest point algorithm and an NDT normal distribution algorithm are used to perform registration processing on the three-dimensional processed morphological data to obtain overall morphological data, specifically including:

[0044] The first solution data is determined by optimizing the minimization objective function corresponding to the ICP iterative closest point algorithm; the first solution data includes: a first rotation matrix and a first translation matrix;

[0045] Using the maximized objective function corresponding to the NDT normal distribution algorithm, determine the second solution data; the second solution data includes: a second rotation matrix and a second translation matrix;

[0046] Performing data comparison according to the first solved data to obtain a first registration error;

[0047] Performing data comparison according to the second solved data to obtain a second registration error;

[0048] Determine a shape synthesis algorithm; the shape synthesis algorithm is determined by comparing the first registration error and the second registration error numerically and using the algorithm corresponding to the registration error with the smallest numerical value;

[0049] The three-dimensional processed morphology data is registered according to the morphology synthesis algorithm to obtain overall morphology data.

[0050] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0051] The invention discloses a grinding wheel profile measurement device and method. A four-axis linkage mechanism moves according to a rotation instruction so that a line laser sensor and a blower mechanism are moved to a set position range of a target grinding wheel; the blower mechanism blows air on the surface of the target grinding wheel according to the blower instruction; the line laser sensor emits laser according to the laser emission instruction and collects three-dimensional profile data of the target grinding wheel within the set position range; a control measurement module pre-processes the three-dimensional profile data to obtain three-dimensional processed profile data; an optimized ICP iterative closest point algorithm and an NDT normal distribution algorithm are used to perform registration processing on the three-dimensional processed profile data to obtain overall profile data; the invention can realize rapid and accurate measurement of the microscopic profile and macroscopic size of the grinding wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 A schematic diagram of a measuring device provided in an embodiment of the present invention;

[0054] Figure 2 A simplified schematic diagram of a measuring device provided in an embodiment of the present invention;

[0055] Figure 3 A schematic diagram of a portion of the structure of a measuring device provided in an embodiment of the present invention;

[0056] Figure 4 A schematic diagram of the position and posture of a four-axis motion mechanism provided in an embodiment of the present invention;

[0057] Figure 5 A schematic diagram of the specific process for determining the overall morphology of the grinding wheel;

[0058] Figure 6 Schematic diagram of the three-dimensional morphology measurement results of the grinding wheel. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] The purpose of the present invention is to provide a grinding wheel profile measuring device and method, aiming to achieve rapid and accurate measurement of the microscopic profile and macroscopic size of the grinding wheel.

[0061] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] Example 1

[0063] like Figure 1 As shown, an embodiment of the present invention provides a grinding wheel profile measuring device, which includes: a four-axis linkage mechanism, a line laser sensor, a blower mechanism, and a control and measurement module.

[0064] The four-axis linkage mechanism, the line laser sensor and the air blowing mechanism are all connected to the control and measurement module; the line laser sensor and the air blowing mechanism are arranged on the four-axis linkage mechanism, and the air blowing mechanism is arranged below the line laser sensor.

[0065] The control and measurement module is used to issue control instructions; the control instructions include: rotation instructions, blowing instructions and laser emission instructions.

[0066] The four-axis linkage mechanism is used to move according to the rotation instruction so that the line laser sensor and the blower mechanism are moved to the set position range of the target grinding wheel; the set position range is the range from the end position to the side position.

[0067] The air blowing mechanism is used for blowing air to the surface of the target grinding wheel according to the air blowing instruction.

[0068] The line laser sensor is used to emit laser according to the laser emission instruction and collect three-dimensional morphological data of the target grinding wheel within the set position range; the three-dimensional morphological data includes: end face morphological data and side face morphological data; the morphological data includes: thickness parameters and surface parameters.

[0069] The control and measurement module is also used to pre-process the three-dimensional shape data to obtain three-dimensional processed shape data; the pre-processing includes: filtering and noise reduction and interpolation and filling data processing.

[0070] The control measurement module is also used to use the optimized ICP iterative closest point algorithm and the NDT normal distribution algorithm to perform registration processing on the three-dimensional processed morphology data to obtain the overall morphology data.

[0071] As an optional implementation, the four-axis linkage mechanism includes: an X-axis slide, a first swing arm mechanism, a second swing arm mechanism and a Y-axis motion mechanism.

[0072] The X-axis slide table and the Y-axis motion mechanism are vertically arranged; one end of the first swing arm mechanism is arranged on the X-axis slide table; and the other end of the first swing arm mechanism is connected with one end of the second swing arm mechanism.

[0073] The other end of the second swing arm mechanism is arranged on the Y-direction motion mechanism. The line laser sensor and the blower mechanism are arranged on the Y-direction motion mechanism; the X-direction slide table, the first swing arm mechanism, the second swing arm mechanism and the Y-direction motion mechanism are all connected to the control and measurement module.

[0074] Specifically, the X-axis slide table includes: a slide table drive motor, a slide table fixing seat, a slide table lead screw and a first motion support plate.

[0075] The slide fixing seat is arranged on the ground; the slide driving motor is connected with the first moving support plate via the slide lead screw; the slide driving motor and the first moving support plate are both arranged on the slide fixing seat; the slide driving motor is connected with the control and measurement module.

[0076] The first swing arm mechanism comprises: a reducer, a first swing arm motor, a first swing arm and a first swing arm rotating shaft.

[0077] The reducer is arranged on the first moving support plate; the first swing arm motor is arranged above the reducer, and the first swing arm motor is connected to the reducer.

[0078] One end of the first swing arm is arranged above the reducer through the first swing arm rotating shaft; the other end of the first swing arm is connected to one end of the second swing arm mechanism.

[0079] The first swing arm is connected to the first swing arm motor; the first swing arm motor is also connected to the control and measurement module.

[0080] The second swing arm mechanism includes: a second swing arm, a second swing arm motor and a second swing arm rotating shaft.

[0081] One end of the second swing arm is connected to the other end of the first swing arm via the second swing arm rotating shaft.

[0082] The other end of the second swing arm is arranged on the Y-direction motion mechanism; the second swing arm motor is arranged above the second swing arm, and the second swing arm motor is connected to the second swing arm; the second swing arm motor is also connected to the control and measurement module.

[0083] In one embodiment, the distance between the line laser sensor and the measuring surface of the target grinding wheel is in the range of 20 mm±3 mm.

[0084] Example 2

[0085] An embodiment of the present invention provides a method for measuring the profile of a grinding wheel, the method comprising:

[0086] The three-dimensional shape data of the target grinding wheel within the set position range is obtained. The three-dimensional shape data includes: end face shape data and side face shape data; the shape data includes: thickness parameters and surface shape parameters.

[0087] The three-dimensional shape data is preprocessed to obtain three-dimensional processed shape data. The preprocessing includes: filtering noise reduction and interpolation filling data processing.

[0088] The optimized ICP iterative closest point algorithm and NDT normal distribution algorithm are used to register the three-dimensional processed morphological data to obtain the overall morphological data.

[0089] As an optional implementation method, preprocessing the three-dimensional morphological data to obtain three-dimensional processed morphological data specifically includes:

[0090] The three-dimensional shape data is interpolated and filled to obtain filled data.

[0091] Perform point cloud translation transformation on the filling data to obtain point cloud transformation data.

[0092] Mean filtering is used to perform filtering and fitting processing based on the set threshold vector according to the point cloud transformation data to obtain the fitting data.

[0093] The fitting data is corrected by using the least square method to obtain corrected data.

[0094] The correction data is determined as three-dimensional processed topography data.

[0095] In one embodiment, the optimized ICP iterative closest point algorithm and the NDT normal distribution algorithm are used to perform registration processing on the three-dimensional processed morphological data to obtain the overall morphological data, which specifically includes:

[0096] The first solution data is determined by optimizing the minimization objective function corresponding to the ICP iterative closest point algorithm; the first solution data includes: a first rotation matrix and a first translation matrix.

[0097] The second solution data is determined by using the maximized objective function corresponding to the NDT normal distribution algorithm; the second solution data includes: a second rotation matrix and a second translation matrix.

[0098] Data comparison is performed according to the first solution data to obtain a first registration error.

[0099] Data comparison is performed based on the second solution data to obtain a second registration error.

[0100] Determine a shape synthesis algorithm; the shape synthesis algorithm is determined by comparing the first registration error and the second registration error numerically, and the algorithm corresponding to the registration error with the smallest numerical value is determined.

[0101] The three-dimensional processed morphology data is registered according to the morphology synthesis algorithm to obtain the overall morphology data.

[0102] In practical applications, in order to solve the problem of difficulty in measuring the shape and size of the grinding wheel in multi-axis grinding processing, the three-dimensional shape of the grinding wheel is measured based on the four-axis linkage mechanism and the line laser measurement sensor. At the same time, the supporting blower mechanism is used to remove the grinding fluid and dirt on the surface of the grinding wheel, so as to realize the precise measurement of the shape and size of the grinding wheel in situ.

[0103] First, the blowing device is moved to the specified position through the four-axis linkage mechanism, and then the grinding wheel is controlled to rotate through the machine tool CNC system. At this time, the blowing device starts to work to remove the grinding fluid and dirt on the surface of the grinding wheel to ensure that the surface of the grinding wheel is clean and does not affect the grinding wheel morphology and size measurement results. After the grinding wheel is blown for 1 minute, the grinding wheel is controlled to stop rotating.

[0104] After removing the grinding fluid and dirt from the surface of the grinding wheel, the line laser sensor is switched to the specified position to measure the end face morphology and cylindrical surface morphology of the grinding wheel. During the measurement process, the CNC system of the machine tool controls the rotation of the grinding wheel again to obtain the three-dimensional morphology of the grinding wheel, and the end face morphology and side morphology of the grinding wheel are obtained.

[0105] After the measurement is completed, the four-axis linkage mechanism and the line laser sensor should be reset to the specified position to ensure that they avoid the working tool path of the multi-axis grinder and prevent the line laser sensor from being damaged by grinding fluid and chips.

[0106] The obtained grinding wheel side profile data and end face profile data need to be preprocessed by filtering and noise reduction. For the positions not measured by the laser sensor, interpolation filling data processing is required. After completing the above data preprocessing, the end face and side face profiles are registered by optimizing the ICP iterative closest point algorithm and the NDT normal distribution algorithm to synthesize the overall shape of the grinding wheel. After the overall shape data of the grinding wheel is obtained, the axial and radial line profiles of the grinding wheel should have visualization functions.

[0107] After the overall morphology of the grinding wheel is synthesized, post-processing should be performed, including: visualization of the axial and circumferential line profiles of the grinding wheel, output of grinding wheel diameter and thickness parameters, grinding wheel surface parameters, and root mean square error output calculation.

[0108] A schematic diagram of the measuring device is shown in Figure 2 As shown, the connection sequence is: mobile joint 1 to rotation joint 2 to rotation joint 3 to mobile joint 2, wherein mobile joint 1 controls the movement in the X direction and is responsible for adjusting the distance from the target grinding wheel to the blower mechanism and the line laser sensor; rotation joint 2 and rotation joint 3 are responsible for adjusting the measurement position of the line laser sensor, that is, they are responsible for adjusting the sampling position of the line laser sensor from the end face position of the target grinding wheel to the side position; mobile joint 2 is responsible for adjusting the measurement position and the position of the blower mechanism.

[0109] The air blowing mechanism needs to be connected to an external air source and placed below the line laser sensor. The installation position should ensure that the air blowing will not pollute the laser emission and receiving working accuracy of the line laser sensor.

[0110] like Figure 3 As shown, the X-axis slide table is composed of a slide table drive motor, a slide table fixed seat, a slide table lead screw and a moving support plate; the first swing arm is installed on the moving support plate and can move in the X direction; the first swing arm mechanism is composed of a reducer, a swing arm motor and the first swing arm.

[0111] The second swing arm is connected to the end of the first swing arm, including: a second swing arm, a second swing arm motor; the end of the second swing arm is connected to the Y-axis slide, wherein the Y-axis slide includes: a screw motor, an actuator screw, an optical axis and an optical axis fixing seat, and a moving pallet; wherein a placement line laser sensor and a blower mechanism are installed on the moving pallet.

[0112] The first swing arm motor is installed on the reducer, and the second swing arm motor and the lead screw motor are installed on the second swing arm.

[0113] The method for measuring the grinding wheel profile is to first move the blower mechanism to the specified position through the four-axis linkage mechanism, requiring that the line laser sensor to the surface to be measured of the target grinding wheel should be within 20mm±3mm; before measurement, the grinding wheel should be cleaned first, and the specific cleaning process is as follows: the grinding wheel is rotated by the machine tool CNC system, and the blower starts to work at this time, spraying high-pressure air to remove the grinding fluid and dirt on the surface of the grinding wheel to ensure that the surface of the grinding wheel is clean and does not affect the grinding wheel profile and size measurement results. After the grinding wheel is cleaned for a certain period of time, Example 1 is to blow air for 1 minute, and the grinding wheel is controlled to stop rotating. At this time, the grinding wheel cleaning is completed.

[0114] After removing the grinding fluid and dirt from the surface of the grinding wheel, the line laser sensor is switched to the specified position to measure the end face morphology and cylindrical surface morphology of the target grinding wheel. During the measurement process, the grinding wheel rotation is controlled again by the machine tool CNC system to obtain the end face morphology and side morphology of the grinding wheel.

[0115] The X-axis position of the line laser sensor is controlled by the slide motor. By adjusting the slide displacement, the distance between the grinding wheel surface to be measured and the line laser probe can be controlled. The first swing arm and the second swing arm are controlled by two swing arm motors respectively. By adjusting the swing arm motor rotation angle, the swing arm position direction can be adjusted, and then the line laser measurement direction can be controlled in the parallel direction or vertical direction of the grinding wheel axis; the Y-axis position of the line laser is adjusted by the screw motor driving the moving support plate, and the blowing action is also completed by the screw motor driving the moving support plate.

[0116] During the measurement of the end face and side face of the grinding wheel, the four-axis motion mechanism should include at least two positions, such as Figure 4 As shown. Position 1 is the measurement position of the side of the target grinding wheel, at this time, the second swing arm is parallel to the x-rail, and the first swing arm is at a 45° angle to the x-rail. The line laser sensor measurement action and the blowing action are driven by the Y-axis lead screw motor; Position 2 is the measurement position of the end face of the target grinding wheel, at this time, the second swing arm is perpendicular to the x-rail, and the first swing arm is parallel to the x-rail. The line laser sensor measurement action and the blowing action are driven by the Y-axis lead screw motor. During the measurement process, the line laser sensor maintains the relative position with the surface to be measured unchanged.

[0117] After the measurement is completed, it should be reset to the specified position to ensure that it avoids the working path of the multi-axis grinder and prevents the line laser sensor from being damaged by grinding fluid and chips.

[0118] The obtained grinding wheel side and end surface topography data need to be pre-processed such as outlier removal, filtering, interpolation and tilt correction.

[0119] Assume that the grinding wheel point cloud can be expressed as [X, Y, Z], where X = {x1, x2, …, x N}, Y={y1,y2,…,y N}, Z={z1,z2,…,z N}, the point cloud is translated to the origin of the coordinate system, that is, the origin is the geometric center, and the processed point cloud can be expressed as [X o , Y o , Z o ], and its mathematical process can be expressed as:

[0120]

[0121] Among them, N p is the number of coordinate points in the measured point cloud.

[0122] Considering that the grinding wheel structure can be divided into side and end faces, the transformed [X o ,Y o ,Z o ] can be divided into side point cloud [X oc , Y oc , Z oc ] and end face point cloud [X oe , Y oe , Z oe ] two parts, and their outliers can be represented by [X c_out , Y c_out , Z c_out ] and end face point cloud [X e_out , Y e_out , Z e_out ], its discriminant is:

[0123]

[0124] If the above formula is satisfied, it is considered as an outlier point [X c_out , Y c_out , Z c_out ], E is the set threshold vector. The filtering process uses mean filtering, that is, for the current sampling point to be processed, a spherical template is constructed. The template consists of a sphere D(x0, y0, z0) = {(x, y, z) | (x-x0) 2 +(y-y0) 2 +(z-z0) 2 <d 2 The mean filter uses the template mean to replace the current sampling point. For a 3D point cloud, the value at a sampling point (x0, y0, z0) in the 3D point cloud is replaced by the average value of its neighborhood point set. The specific process can be expressed as:

[0125]

[0126] After the above transformation process, the coordinates of the undetermined point are fitted with the linear equation z0=a0+a1x+a2y, where a0, a1, and a2 are the undetermined coefficients, which can be solved by the three data points closest to the undetermined point. The measured point cloud is further tilted and corrected; the point cloud plane equation z=a0x+a1y+a2 is fitted by the least squares method; where a0, a1, and a2 are coefficients, which can be solved by the least squares method. The plane point cloud of the fitted plane point cloud can be expressed as [X f , Y f , Z f ], the point cloud data after tilt correction can be obtained by subtracting the interpolated point cloud from the plane point cloud, which can be expressed as [X, Y, Z].

[0127] Through the above processing, the corrected grinding wheel measurement morphology is obtained. The end face morphology and side face morphology are registered with the standard grinding wheel model point cloud by optimizing the ICP iterative closest point algorithm and the NDT normal distribution algorithm, and the overall morphology of the grinding wheel is synthesized. Figure 5 shown.

[0128] The ICP iterative closest point algorithm minimizes the objective function Solve the rotation matrix R _ICP and the translation matrix T _ICP .q i represents the coordinate point in the transformed target point cloud, R represents a rotation matrix, and T represents a translation matrix. i Represents the coordinate points in the measured point cloud.

[0129] The NDT algorithm maximizes the objective function Solve the rotation matrix R _NDT and the translation matrix T _NDT ; Ψ represents a likelihood function, Represents the coordinate points in the measured point cloud.

[0130] Compare the R obtained by the ICP iterative closest point algorithm _ICP and T _ICP And R obtained by NDT normal distribution algorithm _NDT and T _NDT The obtained registration error is selected to obtain the smallest registration error algorithm, and the rotation and translation matrices calculated by the algorithm are selected as the final synthesis algorithm.

[0131] After the overall shape of the grinding wheel is synthesized, post-processing should be performed, including: visualization of the axial and circumferential line profiles of the grinding wheel, output of the grinding wheel diameter and thickness parameters, calculation of the grinding wheel surface parameters and root mean square error output. Figure 6 shown.

[0132] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A grinding wheel profile measuring device, characterized in that: The device comprises: a four-axis linkage mechanism, a line laser sensor, a blower mechanism, and a control and measurement module; The four-axis linkage mechanism, the line laser sensor and the air blowing mechanism are all connected to the control and measurement module; The line laser sensor and the air blowing mechanism are arranged on the four-axis linkage mechanism, and the air blowing mechanism is arranged below the line laser sensor; The control and measurement module is used to issue control instructions; the control instructions include: rotation instructions, blowing instructions and laser emission instructions; The four-axis linkage mechanism is used to move according to the rotation instruction so that the line laser sensor and the air blowing mechanism are moved to a set position range of the target grinding wheel; the set position range is a range from the end surface position to the side surface position; The air blowing mechanism is used to perform air blowing treatment on the surface of the target grinding wheel according to the air blowing instruction; The line laser sensor is used to emit laser according to the laser emission instruction, and collect three-dimensional shape data of the target grinding wheel within a set position range; the three-dimensional shape data includes: end face shape data and side face shape data; the shape data includes: thickness parameters and surface shape parameters; The control and measurement module is also used for: Preprocessing the three-dimensional shape data to obtain three-dimensional processed shape data; the preprocessing includes: filtering and noise reduction and interpolation and filling data processing; The optimized ICP iterative closest point algorithm and the NDT normal distribution algorithm are used to perform registration processing on the three-dimensional processed morphological data to obtain the overall morphological data.

2. The grinding wheel profile measuring device according to claim 1, characterized in that: The four-axis linkage mechanism includes: an X-axis slide, a first swing arm mechanism, a second swing arm mechanism and a Y-axis motion mechanism; The X-axis slide and the Y-axis motion mechanism are arranged vertically; one end of the first swing arm mechanism is arranged on the X-axis slide; the other end of the first swing arm mechanism is connected to one end of the second swing arm mechanism; The other end of the second swing arm mechanism is arranged on the Y-direction motion mechanism; The line laser sensor and the air blowing mechanism are arranged on the Y-direction motion mechanism; The X-axis slide table, the first swing arm mechanism, the second swing arm mechanism and the Y-axis motion mechanism are all connected to the control and measurement module.

3. The grinding wheel profile measuring device according to claim 2, characterized in that: The X-axis slide table comprises: a slide table driving motor, a slide table fixing seat, a slide table lead screw and a first motion support plate; The slide fixing seat is arranged on the ground; The slide drive motor is connected to the first motion support plate via the slide lead screw; the slide drive motor and the first motion support plate are both arranged on the slide fixing seat; The slide drive motor is connected to the control and measurement module.

4. The grinding wheel profile measuring device according to claim 3, characterized in that: The first swing arm mechanism comprises: a reducer, a first swing arm motor, a first swing arm and a first swing arm rotating shaft; The reducer is arranged on the first moving support plate; the first swing arm motor is arranged above the reducer, and the first swing arm motor is connected to the reducer; One end of the first swing arm is arranged above the reducer through the first swing arm rotating shaft; the other end of the first swing arm is connected to one end of the second swing arm mechanism; The first swing arm is connected to the first swing arm motor; the first swing arm motor is also connected to the control and measurement module.

5. The grinding wheel profile measuring device according to claim 4, characterized in that: The second swing arm mechanism comprises: a second swing arm, a second swing arm motor and a second swing arm rotating shaft; One end of the second swing arm is connected to the other end of the first swing arm via the second swing arm rotating shaft; The other end of the second swing arm is arranged on the Y-direction motion mechanism; The second swing arm motor is arranged above the second swing arm, and the second swing arm motor is connected to the second swing arm; the second swing arm motor is also connected to the control and measurement module.

6. The grinding wheel profile measuring device according to claim 1, characterized in that: The distance between the line laser sensor and the measuring surface of the target grinding wheel ranges from 20 mm ± 3 mm.

7. A method for measuring the profile of a grinding wheel, characterized in that: The method comprises: Acquire three-dimensional topographic data of the target grinding wheel within a set position range; the three-dimensional topographic data includes: end face topographic data and side face topographic data; the topographic data includes: thickness parameters and surface shape parameters; Preprocessing the three-dimensional shape data to obtain three-dimensional processed shape data; the preprocessing includes: filtering and noise reduction and interpolation and filling data processing; The optimized ICP iterative closest point algorithm and the NDT normal distribution algorithm are used to perform registration processing on the three-dimensional processed morphological data to obtain the overall morphological data.

8. The grinding wheel profile measurement method according to claim 7, characterized in that: Preprocessing the three-dimensional morphological data to obtain three-dimensional processed morphological data specifically includes: Performing interpolation and filling data processing on the three-dimensional shape data to obtain filling data; Performing point cloud translation transformation on the filling data to obtain point cloud transformation data; Using mean filtering, filtering and fitting processing are performed based on the set threshold vector according to the point cloud transformation data to obtain fitting data; The fitting data are corrected by using the least square method to obtain corrected data; The correction data is determined as the three-dimensional processed topography data.

9. The grinding wheel profile measurement method according to claim 7, characterized in that: The optimized ICP iterative closest point algorithm and the NDT normal distribution algorithm are used to perform registration processing on the three-dimensional processed morphological data to obtain the overall morphological data, which specifically includes: The first solution data is determined by optimizing the minimization objective function corresponding to the ICP iterative closest point algorithm; the first solution data includes: a first rotation matrix and a first translation matrix; Using the maximized objective function corresponding to the NDT normal distribution algorithm, determine the second solution data; the second solution data includes: a second rotation matrix and a second translation matrix; Performing data comparison according to the first solved data to obtain a first registration error; Performing data comparison according to the second solved data to obtain a second registration error; Determine a shape synthesis algorithm; the shape synthesis algorithm is determined by comparing the first registration error and the second registration error numerically and using the algorithm corresponding to the registration error with the smallest numerical value; The three-dimensional processed morphology data is registered according to the morphology synthesis algorithm to obtain overall morphology data.

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