Workpiece surface roughness detection apparatus and method

Abstract

This invention provides a workpiece surface roughness detection device and method. The device includes: a detection table having a guide rail groove whose axis passes through a central reference point, a reference workpiece groove and a comparison workpiece groove that are symmetrical about the central reference point; an electric guide rail slider module including an electric drive mechanism, a guide rail and a slider, the slider being fitted onto the guide rail and driven by the electric drive mechanism for distance measurement; a first non-contact distance sensor fixed on the slider, with the detection direction facing the reference workpiece groove; a second non-contact distance sensor fixed on the slider, with the detection direction facing the comparison workpiece groove; and a central control unit electrically connected to the electric drive mechanism, the first non-contact distance sensor, and the second non-contact distance sensor; the first and second non-contact distance sensors are the same type of non-contact distance sensor. This device utilizes the known characteristics of the surface contour of the reference workpiece to adjust the comparison distance data in real time, improving detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of testing equipment, and specifically to a workpiece surface roughness testing device and method. Background Technology

[0002] Surface roughness refers to the microscopic geometric profile characteristics after contour filtering (removing shape errors and waviness), and is a quantitative indicator of the microscopic unevenness of a machined surface. In terms of data volume, the data volume of shape error is generally greater than 10 mm, the data volume of waviness is between 1 mm and 10 mm, and the data volume of roughness is generally less than 1 mm.

[0003] Surface roughness is typically measured using a cross-sectional profile perpendicular to the surface. Depending on the application scenario and usage habits, surface roughness can generally be measured using the arithmetic mean deviation. Maximum height difference Root mean square roughness In the field of machining, parameters such as the arithmetic mean deviation are generally used. As an indicator for measuring surface roughness.

[0004] According to GB / T 10610, surface roughness testing requires four steps: sampling, filtering, evaluation, and parameter calculation. In the sampling step, a representative length is selected on the workpiece surface for measuring the microscopic data of the profile. In the filtering step, shape errors and waviness are removed. In the evaluation step, the sampling length is selected based on actual needs, and the evaluation length (generally five times the sampling length) is determined accordingly. After selecting several detection positions based on the shape of the surface to be tested, the microscopic data of the profile at each detection position is obtained with the evaluation length as a reference. Then, using the sampling length as the smallest unit, the arithmetic mean deviation within each sampling length of the profile microscopic data is calculated. And finally, the arithmetic mean deviation of all sampling lengths. The mean of the values ​​is used as the arithmetic mean deviation of the assessment length. value.

[0005] Non-contact ranging sensors are a commonly used type of ranging sensor. Obtaining the surface contour information of a workpiece using a non-contact ranging sensor to deduce its surface roughness information is a common technical method. As precision electronic inspection devices, non-contact ranging sensors are subject to systematic and random errors during measurement. Generally, systematic errors originate from the ranging system itself, composed of the non-contact ranging sensor and the workpiece being measured, while random errors arise from objective factors that cannot be stably adjusted. Therefore, reducing or mitigating the errors of non-contact ranging sensors to enable their better application in surface roughness detection is one of the technical problems that the industry needs to solve. Summary of the Invention

[0006] This invention provides a workpiece surface roughness detection device and method. The workpiece surface roughness detection device, through reasonable structural design, utilizes the known characteristics of the surface contour of the reference workpiece to adjust the comparison distance data in real time, thereby reducing the systematic error in the measurement system to a certain extent and having good practicality.

[0007] This invention provides a workpiece surface roughness detection device, comprising:

[0008] The testing table has a central reference point located on the top surface, a guide rail groove whose axis passes through the central reference point, a reference workpiece groove and a comparison workpiece groove that are symmetrical about the central reference point;

[0009] An electric guide rail slider module includes an electric drive mechanism, a guide rail, and a slider. The slider is fitted on the guide rail and driven by the electric drive mechanism for ranging. The guide rail is tightly fitted into the guide groove.

[0010] The first non-contact ranging sensor is fixed on the slider, and the detection direction is towards the side of the reference workpiece groove;

[0011] The second non-contact ranging sensor is fixed on the slider, and the detection direction is towards the side of the comparison workpiece groove;

[0012] The central control unit is electrically connected to the electric drive mechanism, the first non-contact ranging sensor, and the second non-contact ranging sensor, respectively.

[0013] The first non-contact ranging sensor and the second non-contact ranging sensor are the same type of non-contact ranging sensor.

[0014] In an optional implementation, the first non-contact ranging sensor is a laser triangulation displacement sensor or a capacitive sensor.

[0015] In an optional implementation, the first non-contact ranging sensor is a laser triangulation displacement sensor or a capacitive sensor.

[0016] In an optional embodiment, the axis of the reference workpiece groove is parallel to the axis of the guide rail groove; or the axis of the reference workpiece groove and the axis of the guide rail groove have an angle.

[0017] Accordingly, the present invention provides a method for detecting the surface roughness of a workpiece, implemented based on the aforementioned workpiece surface roughness detection equipment, comprising:

[0018] Place a reference workpiece in the reference workpiece slot and a comparison workpiece in the comparison workpiece slot;

[0019] The central control unit controls the electric drive mechanism to drive the slider to move from one end of the guide rail to the other end. During the movement of the slider, the detection point of the first non-contact ranging sensor moves along the reference trajectory on the surface of the reference workpiece, and the detection point of the second non-contact ranging sensor moves along the comparison trajectory on the surface of the comparison workpiece.

[0020] The central control unit synchronously receives the effective reference distance fed back by the first non-contact ranging sensor. The effective comparison distance fed back by the second non-contact ranging sensor And generate reference distance functions respectively. and contrast distance function , For the data collection location on the reference trajectory, To compare the data collection locations on the trajectory;

[0021] Given the microscopic contour data of the reference workpiece on the reference trajectory, a continuous reference distance function is constructed using the microscopic contour data. ;

[0022] Using the aforementioned reference distance function and the reference distance function The difference in the contrast distance function After correction, the discrete corrected distance function is obtained. ;

[0023] Based on the selected surface roughness item, the discrete correction distance function To determine the evaluation value of the surface roughness item for the comparison workpiece on the comparison trajectory for reference;

[0024] in, , , , The lengths of the reference trajectory and the comparison trajectory.

[0025] Optional implementation methods, , , .

[0026] An optional implementation uses the reference distance function. and the reference distance function The difference in the contrast distance function After correction, the discrete corrected distance function is obtained. include:

[0027] Calculate the discrete error distance function ;

[0028] Fit the discrete error distance function with a preset function. The continuous error distance function is obtained. ;

[0029] Calculate the corrected discrete distance function .

[0030] In an optional implementation, the preset function is a periodic function.

[0031] In an optional implementation, the reference distance function Reference distance in The accuracy of the value is greater than that of the effective reference distance. It is at least an order of magnitude higher.

[0032] This invention provides a workpiece surface roughness detection device and method. The workpiece surface roughness detection device, through reasonable structural design, utilizes the known characteristics of the surface contour of the reference workpiece to adjust the comparison distance data in real time, which reduces the systematic error in the measurement system to a certain extent and has good practicality. Attached Figure Description

[0033] Figure 1 This is a three-dimensional structural schematic diagram of the workpiece surface roughness detection device according to an embodiment of the present invention.

[0034] Figure 2 This is a top view of the workpiece surface roughness detection device according to an embodiment of the present invention (with a reference workpiece and a comparison workpiece placed on it).

[0035] Figure 3 This is a partially enlarged structural diagram of the reference workpiece in an embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram of the connection structure of the central control host in an embodiment of the present invention.

[0037] Figure 5This is a flowchart of the workpiece surface roughness detection method according to an embodiment of the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Figure 1 This is a three-dimensional structural schematic diagram of the workpiece surface roughness detection device according to an embodiment of the present invention.

[0040] Figure 2 This is a top view of the workpiece surface roughness detection device according to an embodiment of the present invention (with a reference workpiece and a comparison workpiece placed on it).

[0041] Figure 3 This is a partially enlarged structural diagram of the reference workpiece in an embodiment of the present invention.

[0042] Figure 4 This is a schematic diagram of the connection structure of the central control host in an embodiment of the present invention.

[0043] Specifically, this invention discloses a workpiece surface roughness detection device, comprising:

[0044] The testing platform 1 has a central reference point located on the top surface, a guide rail groove 2 whose axis passes through the central reference point, a reference workpiece groove 75 and a comparison workpiece groove 12 that are symmetrical about the central reference point. It should be noted that the workpiece surface roughness testing equipment of this embodiment is mainly used for roughness testing of the flat surface of the workpiece. Accordingly, the surfaces (abutting surfaces) of the reference workpiece groove 75 and the comparison workpiece groove 12 that are close to the guide rail groove 2 are both flat. In practical applications, the measured surface of the reference workpiece 11 and the measured surface of the comparison workpiece 12 can be fitted onto the corresponding abutting surfaces to achieve positioning.

[0045] The electric guide rail 3 slider 4 module includes an electric drive mechanism, a guide rail 3 and a slider 4. The slider 4 is fitted on the guide rail 3 and driven by the distance measuring electric drive mechanism. The guide rail 3 is tightly fitted into the guide groove. In practical applications, the electric guide rail 3 slider 4 module can adopt existing modules to save costs.

[0046] The first non-contact ranging sensor 6 is fixed on the slider 4, and the detection direction is towards the side of the reference workpiece groove 75.

[0047] The second non-contact ranging sensor 8 is fixed on the slider 4, and the detection direction is towards the groove side of the comparison workpiece 12.

[0048] The central control unit is electrically connected to the electric drive mechanism, the first non-contact ranging sensor 6, and the second non-contact ranging sensor 8, respectively.

[0049] In specific implementation, the first non-contact ranging sensor 6 and the second non-contact ranging sensor 8 are the same type of non-contact ranging sensor. In addition, to reduce the complexity of calculation, the first non-contact ranging sensor 6 and the second non-contact ranging sensor 8 are generally symmetrically arranged on the slider 4 about the axis of the guide rail 3. In actual implementation, the detection directions of the first non-contact ranging sensor 6 and the second non-contact ranging sensor 8 are opposite, and the detection directions of the first non-contact ranging sensor 6 and the second non-contact ranging sensor 8 are both perpendicular to the axis of the guide rail 3. Furthermore, preferably, the line connecting the detection point of the first non-contact ranging sensor 6 and the detection point of the second non-contact ranging sensor 8 is perpendicular to the axis of the guide rail 3.

[0050] It should be noted that, since the object to be detected in the embodiments of the present invention is the surface roughness of the workpiece, and the surface roughness of different workpieces varies, the above descriptions of distance and orientation related to "detection point" and "symmetry" refer to the ideal setting. If the contour characterizing the surface roughness is taken as the microstructure, then the above restrictions on distance, etc. are observations on a macro scale.

[0051] Refer to the attached diagram. Figure 3 The enlarged schematic diagram of the reference workpiece 11 shows that the measured surface of the reference workpiece 11 is characterized by a reference line to represent the macroscopic scale, and its microstructure has undulations.

[0052] Optionally, the first non-contact ranging sensor 6 is a laser triangulation displacement sensor or a capacitive sensor; similarly, the first non-contact ranging sensor 6 is a laser triangulation displacement sensor or a capacitive sensor.

[0053] Optionally, in actual implementation, the axis of the reference workpiece groove 75 is parallel to the axis of the guide rail groove 2; or the axis of the reference workpiece groove 75 and the axis of the guide rail groove 2 form an angle. When the axis of the reference workpiece groove 75 is parallel to the axis of the guide rail groove 2, the data acquired by the sensor does not require compensation; when the axis of the reference workpiece groove 75 and the axis of the guide rail groove 2 form an angle, the data acquired by the sensor needs to be compensated for the distance caused by the workpiece tilt during processing.

[0054] Figure 5This is a flowchart of a workpiece surface roughness detection method according to an embodiment of the present invention. The present invention provides a workpiece surface roughness detection method, implemented based on the aforementioned workpiece surface roughness detection equipment, including:

[0055] S101: Place a reference workpiece in the reference workpiece slot and a comparison workpiece in the comparison workpiece slot;

[0056] S102: The central control unit controls the electric drive mechanism to drive the slider to move from one end of the guide rail to the other end;

[0057] During the movement of the slider, the detection point of the first non-contact ranging sensor moves along the reference trajectory on the surface of the reference workpiece, and the detection point of the second non-contact ranging sensor moves along the comparison trajectory on the surface of the comparison workpiece.

[0058] Refer to the attached diagram. Figure 2 In this embodiment of the invention, the reference trajectory and the comparison trajectory have the same length, wherein the reference trajectory is defined by... It indicates that the comparison trajectory is based on express.

[0059] S103: The central control unit synchronously receives the effective reference distance fed back by the first non-contact ranging sensor. The effective comparison distance fed back by the second non-contact ranging sensor And generate reference distance functions respectively. and contrast distance function ;

[0060] For the data collection location on the reference trajectory, To compare the data collection locations on the trajectory;

[0061] Specifically, the effective comparison distance refers to the data obtained by the first non-contact ranging sensor when detecting the surface of the reference workpiece. Similarly, the effective comparison distance refers to the data obtained by the second non-contact ranging sensor when detecting the surface of the comparison workpiece. The travel of the slider within a certain range at the beginning and end of the stroke is the speed adjustment stroke during idle running. The data obtained by the first and second non-contact ranging sensors during the slider speed adjustment stroke are not considered valid data.

[0062] Specifically, because the sensor has a sampling frequency and the slider moves during the detection process, the effective reference distance fed back by the first non-contact ranging sensor is... The effective comparison distance fed back by the second non-contact ranging sensor These are all distance data corresponding to discrete points. In an ideal state, , , That is, the number of effective distance data obtained by the first non-contact ranging sensor and the second non-contact ranging sensor is the same.

[0063] The fact that two non-contact ranging sensors acquire the same amount of effective distance data is mainly used to limit the installation and positioning accuracy of the two non-contact ranging sensors and to limit the synchronization of data acquisition between the two non-contact ranging sensors.

[0064] First, the length of the reference trajectory of the reference workpiece is the same as the length of the comparison trajectory of the comparison workpiece (in this embodiment of the invention, this distance is defined as...). If the length of the reference trajectory is less than the length of the comparison trajectory, some data will be missing when correcting the comparison distance data on the comparison trajectory. If the length of the reference trajectory is greater than the length of the comparison trajectory, there will be additional useless data in the reference trajectory length (or it can be understood that the additional reference distance data is not included in the scope of the effective reference distance data required by the embodiments of the present invention). Therefore, it is necessary to assume that the lengths of the two are the same.

[0065] Secondly, while it's impossible to guarantee that the measurement errors of the first and second non-contact ranging sensors will be completely consistent during the physical selection process, their sampling frequencies... These are stable parameters, dependent on the excitation and reception / processing speeds of the electrical signal. Therefore, the first and second non-contact ranging sensors of the same model have the same acquisition frequency. However, the same acquisition frequency does not mean that the acquisition is synchronous. In practical applications, the acquisition is not absolutely synchronous between the two.

[0066] Based on this, combined with the uniform motion of the slider (assuming the uniform motion speed is...), Based on the characteristics of the first and second non-contact ranging sensors, the interval between acquiring two consecutive effective distance data is [missing information]. The measured lengths of the reference trajectory and the comparison trajectory are: ; Invent a length error value The value of this length error For the reference trajectory, the length error value is... For the comparison trajectory, the length error value is .

[0067] Specifically, the length error value represents the difference between the actual length of the workpiece trajectory and the actual length span of the sensor sampling data. When the number of effective distance data obtained by the first non-contact ranging sensor and the second non-contact ranging sensor is the same, it indicates that the difference between the positioning position of the detection point of the first non-contact ranging sensor on the reference trajectory and the positioning position of the detection point of the second non-contact ranging sensor on the comparison trajectory is within one... To avoid a significant difference in the detection angles between the two, which would cause them to lose their correlation and comparability.

[0068] Furthermore, due to the limitation of the calculation method for the gap, On the one hand, a faster slider speed indicates a larger allowable margin of error, and vice versa. On the other hand, when selecting a sensor model, a higher sampling frequency results in a smaller allowable margin of error, while a lower sampling frequency results in a larger allowable margin of error. When a user implements the invention according to the embodiments described herein, the implementation logic can reflect the user's required accuracy through the setting of user parameters and automatically adjust the data... and This creates a correlation, meaning that when the user conducts actual testing, after selecting the sensor model, if the slider... If the number of effective distance data acquired by the first non-contact ranging sensor and the second non-contact ranging sensor is inconsistent during high-speed movement, it indicates that... The speed is too high; generally, for accuracy reasons, the slider's movement speed is usually the minimum speed of the device itself. Therefore, when the minimum speed is... If the number of effective distance data obtained by the first non-contact ranging sensor and the second non-contact ranging sensor is inconsistent at a certain speed, it indicates that the performance of the electric slide rail does not meet the usage requirements, and the selection of electric slide rail and sensor needs to be matched.

[0069] It should be noted that the above-described structure is based on the assumption that the line connecting the detection points of the first non-contact ranging sensor and the second non-contact ranging sensor is perpendicular to the axis of the guide rail. This defined structure is an ideal structure, and in actual implementation, slight deviations will generally occur.

[0070] S104: Given the microscopic contour data of the reference workpiece on the reference trajectory, construct a continuous reference distance function using the microscopic contour data. ;

[0071] It should be noted that the continuous reference distance function constructed in this step is a continuous function corresponding to the surface profile on the reference trajectory of the reference workpiece. Since the reference workpiece needs to be highly accurate, its surface finish should be relatively uniform, as in the embodiments of this invention. Figure 3 Similarly, the microscopic contour data of the reference workpiece on the reference trajectory should be storable and expressible by a computer, as illustrated in the embodiments of the present invention, which use a cosine function curve to express the microscopic contour data of the reference workpiece on the reference trajectory.

[0072] S105: Using the aforementioned reference distance function and the reference distance function The difference in the contrast distance function After correction, the discrete corrected distance function is obtained. ;

[0073] Specifically, the reference distance function and the reference distance function The differences are mainly caused by the superposition of systematic errors and random errors, and generally, systematic errors are larger than random errors. Typically, factors such as the jitter of the slider during movement and the straightness of the guide rail can produce relatively serious systematic errors. Therefore, in order to eliminate this part of the systematic error, this embodiment of the invention compares the differences by referring to the measured data and known data of the workpiece. This part of the difference includes systematic errors and random errors. Then, the difference is used to adjust the comparison distance function to obtain the discrete correction distance function.

[0074] In practice, the difference between the two can be calculated through the following steps:

[0075] S201: Calculate the discrete error distance function ;

[0076] It should be noted that the baseline distance function takes discrete values ​​in this step. Correspondingly, the final discrete error distance function is obtained. It is a discrete point set function.

[0077] S202: Fit the discrete error distance function with a preset function. The continuous error distance function is obtained. ;

[0078] In this step, the discrete error distance function is... Fit to continuous error distance function It should be noted that the embodiments of the present invention use a fitting method rather than a substitution method. Fitting aims to closely match the existing data as much as possible while maintaining the continuity of the function. On the one hand, the fitting method can eliminate discrete error distance functions. On the one hand, there are some abnormal values ​​(such as data under extreme error), and on the other hand, the continuous error distance function. It can completely cover all points of action on the entire reference trajectory, thus providing a correction reference for measurement data at any point on the comparison trajectory.

[0079] Specifically, the preset function preferably uses a Fourier series.

[0080] Specifically, based on the processing characteristics of the workpiece surface, the contour on its comparison trajectory is generally periodic. The most ideal function to represent a periodic function is the Fourier series. Other methods, such as the superposition of Gaussian functions, Lorentz functions, and polynomial functions, can also represent periodic functions, but the calculation process is more complicated.

[0081] Specifically, the Fourier series is represented as follows:

[0082]

[0083] in, For the fundamental frequency, and The amplitude and phase of each harmonic. The superposition of harmonics forms the required periodic function.

[0084] S203: Calculate the corrected discrete distance function .

[0085] In this step, the points of the discrete distance function need to be corrected using the continuous error distance function.

[0086] In this process, it is mainly necessary to accurately determine the position of the points of the discrete distance function (points on the comparison trajectory). In this embodiment of the invention, in order to determine the precise position of the points of the discrete distance function, this embodiment of the invention needs to perform calculations with reference to the points of the reference distance function.

[0087] Specifically, during synchronous data acquisition, the positions of the detection points of the first non-contact ranging sensor on the reference trajectory and the positions of the detection points of the second non-contact ranging sensor on the comparison trajectory are somewhat different. The difference comes from two sources: installation error (which is difficult to measure and adjust) and asynchronous acquisition time. Therefore, to confirm the precise position of the points of the discrete distance function, this invention is mainly based on the latter.

[0088] Specifically, although the two sensors have asynchronous acquisition times, they have the same acquisition frequency, that is, the same acquisition time interval. After the central control host receives feedback data from the first non-contact ranging sensor, the next feedback data comes from the second non-contact ranging sensor. The central control host has high precision and measurable accuracy in data acquisition time. Therefore, by using the difference in acquisition time between the two, the central control host can estimate the distance between the location when the latter data was acquired and the location when the former data was acquired with relatively accurate results.

[0089] Specifically, the sampling points for the reference distance function are: The comparison distance function sampling points are: ,in , .

[0090] According to the data received by the central control host and data The order of priority is determined. Accurate methods for estimating location.

[0091] Specifically, if the central control unit receives the valid reference distance first... This indicates that the sampling points of the contrastive distance function are delayed compared to the sampling points of the effective reference function. Therefore, the sampling points of the contrastive distance function... The actual location is , For effective reference distance data And effective comparison distance data The time difference in acquisition.

[0092] Conversely, if the central control unit receives valid comparison distance data first... This indicates that the sampling points of the effective reference function are delayed compared to the sampling points of the comparative distance function. Therefore, the sampling points of the comparative distance function... The actual location is , For effective reference distance data And effective comparison distance data The time difference in acquisition.

[0093] The velocity of the slider when it moves at a constant speed.

[0094] Accordingly, in calculating the corrected discrete distance function At that time, the collection point Position or The substitution ensures the correspondence and rationality of the discrete correction distance function.

[0095] S106: Based on the selected surface roughness item, using the discrete correction distance function For reference, the evaluation value of the surface roughness item of the comparison workpiece on the comparison trajectory is obtained.

[0096] in, , , , The lengths of the reference trajectory and the comparison trajectory.

[0097] Specifically, there are various surface roughness items, such as arithmetic mean deviation. Maximum height difference Root mean square roughness These indicators are calculated based on specific needs in practical applications.

[0098] In summary, the embodiments of the present invention provide a workpiece surface roughness detection device and method. The workpiece surface roughness detection device, through reasonable structural design, utilizes the known characteristics of the surface contour of the reference workpiece to adjust the comparison distance data in real time, thereby reducing the systematic error in the measurement system to a certain extent and having good practicality.

[0099] The workpiece surface roughness detection device and method provided by the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for detecting the surface roughness of a workpiece, characterized in that, This is implemented using a workpiece surface roughness detection device, which includes: a detection table having a central reference point on its top surface, a guide rail groove with its axis passing through the central reference point, a reference workpiece groove and a comparison workpiece groove that are symmetrical about the central reference point; an electric guide rail slider module, including an electric drive mechanism, a guide rail and a slider, the slider being fitted onto the guide rail and driven by the distance measuring electric drive mechanism, the guide rail being tightly fitted into the guide groove; a first non-contact distance measuring sensor fixed on the slider, with its detection direction facing the reference workpiece groove; a second non-contact distance measuring sensor fixed on the slider, with its detection direction facing the comparison workpiece groove; and a central control unit electrically connected to the electric drive mechanism, the first non-contact distance measuring sensor, and the second non-contact distance measuring sensor; the first non-contact distance measuring sensor and the second non-contact distance measuring sensor are the same type of non-contact distance measuring sensor. The method includes: Place a reference workpiece in the reference workpiece slot and a comparison workpiece in the comparison workpiece slot; The central control unit controls the electric drive mechanism to drive the slider to move from one end of the guide rail to the other end. During the movement of the slider, the detection point of the first non-contact ranging sensor moves along the reference trajectory on the surface of the reference workpiece, and the detection point of the second non-contact ranging sensor moves along the comparison trajectory on the surface of the comparison workpiece. The central control unit synchronously receives the effective reference distance fed back by the first non-contact ranging sensor. The effective comparison distance fed back by the second non-contact ranging sensor And generate reference distance functions respectively. and contrast distance function , For the data collection location on the reference trajectory, To compare the data collection locations on the trajectory; Given the microscopic contour data of the reference workpiece on the reference trajectory, a continuous reference distance function is constructed using the microscopic contour data. ; Using the aforementioned reference distance function and the reference distance function The difference in the contrast distance function After correction, the discrete corrected distance function is obtained. ; Based on the selected surface roughness item, the discrete correction distance function To determine the evaluation value of the surface roughness item for the comparison workpiece on the comparison trajectory for reference; in, , , , The lengths of the reference trajectory and the comparison trajectory.

2. The workpiece surface roughness detection method as described in claim 1, characterized in that, ， ， 。 3. The workpiece surface roughness detection method as described in claim 1, characterized in that, Using the aforementioned reference distance function and the reference distance function The difference in the contrast distance function After correction, the discrete corrected distance function is obtained. include: Calculate the discrete error distance function ; Fit the discrete error distance function with a preset function. The continuous error distance function is obtained. ; Calculate the corrected discrete distance function .

4. The workpiece surface roughness detection method as described in claim 3, characterized in that, The preset function is a periodic function.

5. The workpiece surface roughness detection method as described in claim 1, characterized in that, The reference distance function Reference distance in The accuracy of the value is greater than that of the effective reference distance. It is at least an order of magnitude higher.

6. The workpiece surface roughness detection method as described in claim 1, characterized in that, The first non-contact ranging sensor is a laser triangulation displacement sensor or a capacitive sensor.

7. The workpiece surface roughness detection method as described in claim 1, characterized in that, The first non-contact ranging sensor is a laser triangulation displacement sensor or a capacitive sensor.

8. The workpiece surface roughness detection method as described in claim 1, characterized in that, The axis of the reference workpiece groove is parallel to the axis of the guide rail groove; or the axis of the reference workpiece groove and the axis of the guide rail groove have an angle.

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