Step-by-step allowance iterative compensation and error accurate control method for numerical control boring machining

Abstract

The invention provides a step-by-step allowance iterative compensation and error precise control method for numerical control boring machining, which comprises the following steps of: reserving a first machining allowance, a second machining allowance and a third machining allowance in a continuous surface area with two heights during rough boring machining of a boring hole; executing first-time semi-fine boring according to the driving machining equipment, and analyzing to obtain first machining error data; according to the first machining error data, machining compensation data are obtained, the machining equipment is driven to execute second-time semi-finish machining according to the machining compensation data, the first machining error data and the second machining allowance, and second-time semi-finish machining data executed by the equipment are obtained; constructing a numerical control machining compensation model according to the first machining error data and the second machining error data; and optimizing numerical control machining parameters according to the numerical control machining compensation model so as to drive the machining equipment to execute fine boring machining to remove the second machining error data and the third machining allowance. The numerical control boring efficiency and precision can be improved.

Description

Technical Field

[0001] This application relates to the technical field of CNC boring, specifically to a step-by-step allowance iterative compensation and error precision control method for CNC boring. Background Technology

[0002] Boring is a secondary machining process for forged, cast, or drilled holes. It can enlarge the hole diameter, improve machining accuracy, and correct the original hole axis deviation. Existing methods for boring parts with a large depth-to-diameter ratio include deep hole drilling, boring / reaming, deep hole honing, and special machining methods. Methods for measuring hole deviations include general-purpose measuring tools such as inside micrometers, dial indicators, and vernier calipers, suitable for measuring small to medium-sized holes with moderate accuracy. Alternatively, specialized measuring tools such as plug gauges, caliper gauges, and ring gauges can be used. For parts with high precision and complex geometric tolerances, precision instrument methods, such as coordinate measuring machines (CMMs), are employed. For measuring internal holes with extremely large depth-to-diameter ratios, endoscopy combined with image processing technology or inductively coupled micrometers are used. Each measurement and machining technology has its own advantages, disadvantages, and application scenarios.

[0003] Because these processing and measurement methods address only a single problem and can only solve the problem in stages, even if efficiency is improved during processing and inspection, it is often still too low, affecting subsequent production. When processing large batches of deep-diameter hole workpieces with various shapes, the inability to guarantee efficiency and accuracy often leads to a high scrap rate. Therefore, existing boring processes generally suffer from insufficient dimensional control accuracy, high scrap rates, and low processing efficiency when dealing with complex structures such as multi-step holes and deep holes. Summary of the Invention

[0004] The purpose of this application is to overcome the shortcomings and deficiencies in the prior art and provide a step-by-step allowance iterative compensation and error precise control method for CNC boring.

[0005] The first aspect of this application provides a method for step-by-step allowance iterative compensation and precise error control in CNC boring machining, including:

[0006] During rough boring of a hole, an initial machining allowance is reserved in a continuous surface area with two heights; the initial machining allowance includes a first machining allowance, a second machining allowance, and a third machining allowance;

[0007] Based on the first semi-finish boring performed by the driving machining equipment, the first machining error data is analyzed and obtained;

[0008] Based on the first processing error data, processing compensation data is obtained, and the processing equipment is driven to perform a second semi-finishing based on the processing compensation data, the first processing error data and the second processing allowance, so as to obtain the equipment performing the second semi-finishing data.

[0009] Based on the first and second machining error data, a CNC machining compensation model is constructed.

[0010] The CNC machining parameters are optimized according to the CNC machining compensation model to drive the machining equipment to perform fine boring to remove the second machining error data and the third machining allowance.

[0011] As one implementation method, the step of analyzing and obtaining first machining error data based on the first semi-finish boring performed by the driving machining equipment includes:

[0012] After the driving processing equipment executes the process, the dimensions of the stepped processing surface are measured by a high-precision laser diameter measuring instrument to obtain the actual dimensional parameters.

[0013] The machine tool positioning error is obtained by comparing the measured machining coordinate parameters with the coordinates based on CNC machining theory.

[0014] Based on the machine tool positioning error, the comparison of the tool tip profile before and after cutting to calculate the tool wear, and the temperature change data during machining, a first machining error data containing multi-source interference is generated.

[0015] As one implementation, the step of obtaining processing compensation data based on the first processing error data, and driving the processing equipment to perform a second semi-finishing based on the processing compensation data, the first processing error data, and the second processing allowance, to obtain the data for the equipment to perform the second semi-finishing, includes:

[0016] A CNC machining compensation model is constructed based on the first machining error data;

[0017] Machining compensation data is obtained based on the CNC machining compensation model; the machining compensation data includes at least the tool radius compensation value and the feed rate.

[0018] Based on the first machining error data, the second machining allowance, and the machining compensation data, the machining equipment is driven to perform a second semi-finishing process to obtain the second machining error data of the machining equipment performing the second semi-finishing process.

[0019] As one implementation, the step of constructing a CNC machining compensation model based on the first machining error data and the second machining error data includes:

[0020] Based on the first machining error data and the second machining error data, the least squares method is used to analyze the error variation law. The difference between the theoretical value programmed for the first CNC boring machining and the actual measured value is expressed as the first machining error. Similarly, the difference between the theoretical value programmed for the second CNC machining and the actual measured value is expressed as the second machining error.

[0021] Based on the error variation pattern, the first machining error data, and the second machining error data, the CNC machining compensation model is updated or improved.

[0022] As one implementation method, the step of updating or improving the CNC machining compensation model based on the error variation pattern, the first machining error data, and the second machining error data includes:

[0023] If the error variation pattern indicates that the error drifts linearly, a linear compensation model is constructed based on the first machining error data and the second machining error data as the CNC machining compensation model.

[0024] As one implementation method, the step of updating or improving the CNC machining compensation model based on the error variation pattern, the first machining error data, and the second machining error data includes:

[0025] If the error variation pattern indicates that the error is affected by the nonlinear effect of tool wear, after constructing a linear compensation model based on the first machining error data and the second machining error data, a nonlinear correction is introduced into the linear compensation model to obtain the CNC machining compensation model.

[0026] As one implementation method, the CNC machining compensation model is shown in the following formula:

[0027] Δ 补偿 =(D 实测 -D 理论 )×k 温度系数 +δ 刀具磨损

[0028] Where, Δ 补偿 D is the compensation coefficient. 实测 For the actual machining coordinate parameters, D 理论 For theoretical coordinates, k 温度系数 For temperature variation data during processing, δ 刀具磨损 This is the tool wear data during machining.

[0029] As one implementation method, the steps include:

[0030] After performing the second semi-finishing, the radial distribution and axial dimensional deviation of the third machining allowance are obtained by using the multi-point averaging method and measuring multiple sections with a digital micrometer.

[0031] Based on the CNC machining compensation model, obtain the compensation coefficients for the CNC machining parameters;

[0032] The CNC machining parameters for the third machining allowance are optimized based on the radial distribution, the axial dimensional deviation, and the compensation coefficient, so as to perform fine boring to remove the third machining allowance.

[0033] As one implementation method, the step of optimizing the CNC machining parameters for the third machining allowance includes:

[0034] Adjust the cutting speed to the material-compatible range to reduce thermal deformation, and / or adjust the feed rate, and / or reduce cutting force fluctuations.

[0035] In one implementation, the first machining allowance, the second machining allowance, and the third machining allowance are all 0.1 mm.

[0036] Compared to related technologies, the step-by-step allowance iterative compensation and precise error control method for CNC boring in this application reserves an initial machining allowance in a continuous surface area with two heights during rough boring. The initial machining allowance includes a first machining allowance, a second machining allowance, and a third machining allowance. The method analyzes and obtains first machining error data based on the first machining error data. Machining compensation data is obtained based on the first machining error data, and the method drives the machining equipment to perform a second semi-finishing based on the machining compensation data, the first machining error data, and the second machining allowance, resulting in data for the second semi-finishing. A CNC machining compensation model is constructed based on the first and second machining error data. The CNC machining parameters are optimized based on the CNC machining compensation model to drive the machining equipment to perform finish boring to remove the second machining error data and the third machining allowance. This method can instantly correct CNC machining parameters based on errors in multiple stages of the machining process, ensuring high precision while avoiding efficiency losses due to over-machining. It balances machining efficiency with the manufacturing requirements of precision hole systems, significantly reducing the scrap rate.

[0037] To provide a clearer understanding of this application, the specific embodiments of this application will be described below in conjunction with the accompanying drawings. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating a step-by-step allowance iterative compensation and precise error control method for CNC boring machining according to an embodiment of this application.

[0039] Figure 2 This is a schematic diagram of the modules corresponding to the step-by-step allowance iterative compensation and error precise control method for CNC boring machining according to an embodiment of this application.

[0040] Figure 3 This is a circuit diagram of a laser sensor according to one embodiment of this application.

[0041] Figure 4 This is a circuit diagram of a tool temperature acquisition module according to an embodiment of this application.

[0042] Figure 5 This is a circuit diagram of a boost DC power conversion module according to an embodiment of this application. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0044] It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.

[0045] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. The singular forms "a," "the," and "the" used in this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. The word "if" as used herein can be interpreted as "when," "when," or "in response to determination."

[0046] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0047] Please see Figure 1 This is a flowchart of a step-by-step allowance iterative compensation and error precise control method for CNC boring machining according to the first embodiment of this application. The method includes:

[0048] S1: During rough boring of the hole, an initial machining allowance is reserved in a continuous surface area with two heights; the initial machining allowance includes a first machining allowance, a second machining allowance, and a third machining allowance;

[0049] S2: Based on the first semi-finish boring performed by the driving machining equipment, the first machining error data is analyzed and obtained; specifically, based on the removal of the first machining allowance after the first semi-finish boring, the first machining error data with multiple interferences is obtained:

[0050] S3: Based on the first processing error data, obtain processing compensation data, and drive the processing equipment to perform a second semi-finishing based on the processing compensation data, the first processing error data and the second processing allowance, to obtain the equipment's second semi-finishing data.

[0051] S4: Construct a CNC machining compensation model based on the first machining error data and the second machining error data;

[0052] S5: Optimize the CNC machining parameters according to the CNC machining compensation model to drive the machining equipment to perform fine boring to remove the second machining error data and the third machining allowance.

[0053] Compared to related technologies, the step-by-step allowance iterative compensation and precise error control method for CNC boring in this application reserves an initial machining allowance in a continuous surface area with two heights during rough boring. The initial machining allowance includes a first machining allowance, a second machining allowance, and a third machining allowance. The method analyzes and obtains first machining error data based on the first machining error data. Machining compensation data is obtained based on the first machining error data, and the method drives the machining equipment to perform a second semi-finishing based on the machining compensation data, the first machining error data, and the second machining allowance, resulting in data for the second semi-finishing. A CNC machining compensation model is constructed based on the first and second machining error data. The CNC machining parameters are optimized based on the CNC machining compensation model to drive the machining equipment to perform finish boring to remove the second machining error data and the third machining allowance. This method can instantly correct CNC machining parameters based on errors in multiple stages of the machining process, ensuring high precision while avoiding efficiency losses due to over-machining. It balances machining efficiency with the manufacturing requirements of precision hole systems, significantly reducing the scrap rate.

[0054] In a feasible embodiment, step S2: analyzing and obtaining first machining error data based on the first semi-finish boring performed by the driving machining equipment, includes:

[0055] S21: After the driving processing equipment is executed, the dimensions of the step processing surface are detected by a high-precision laser diameter measuring instrument to obtain the measured dimension parameters;

[0056] S22: Obtain the machine tool positioning error based on the difference between the measured machining coordinate parameters and the theoretical coordinates based on CNC machining;

[0057] S23: Calculate the tool wear based on the machine tool positioning error, the comparison of the tool tip profile before and after cutting, and the temperature change data during machining, and generate the first machining error data containing multi-source interference.

[0058] In a feasible embodiment, step S3: obtaining processing compensation data based on the first processing error data, and driving the processing equipment to perform a second semi-finishing based on the processing compensation data, the first processing error data, and the second processing allowance, to obtain the equipment performing the second semi-finishing data, includes:

[0059] S31: Construct a CNC machining compensation model based on the first machining error data;

[0060] S32: Obtain machining compensation data based on the CNC machining compensation model; the machining compensation data includes at least the tool radius compensation value and the feed rate;

[0061] S33: Based on the first machining error data, the second machining allowance, and the machining compensation data, drive the machining equipment to perform a second semi-finishing process to obtain the second machining error data of the machining equipment performing the second semi-finishing process.

[0062] The second machining error data includes the machine tool positioning error when the machining equipment performs the second semi-finishing, the tool wear amount calculated by comparing the tool tip profile before and after cutting, and the temperature change data during machining.

[0063] In a feasible embodiment, step S4: constructing a CNC machining compensation model based on the first machining error data and the second machining error data includes:

[0064] S41: Based on the first machining error data and the second machining error data, the least squares method is used to analyze the error change law. The difference between the theoretical value programmed for the first CNC boring machining and the actual measured value is expressed as the first machining error. Similarly, the difference between the theoretical value programmed for the second CNC machining and the actual measured value is expressed as the second machining error.

[0065] S42: Update or improve the CNC machining compensation model based on the error change pattern, the first machining error data, and the second machining error data.

[0066] The CNC machining compensation model obtained in step S42 can be a new CNC machining compensation model constructed independently of S31, or it can be a compensation model obtained by updating the parameters of the CNC machining compensation model in S31.

[0067] In a feasible embodiment, S42: the step of updating or improving the CNC machining compensation model based on the error variation law, the first machining error data, and the second machining error data includes:

[0068] S421: If the error change pattern indicates that the error drifts linearly, a linear compensation model is constructed based on the first machining error data and the second machining error data as the CNC machining compensation model.

[0069] The CNC machining compensation model corresponding to step S421 is shown in the following formula:

[0070] Δ 补偿 =(D 实测 -D 理论 )×k 温度系数 +δ 刀具磨损

[0071] Where, Δ 补偿 D is the compensation coefficient. 实测 For the actual machining coordinate parameters, D 理论 For the theoretical machining coordinate parameters, k 温度系数 For temperature variation data during processing, δ 刀具磨损 This is the tool wear data during machining.

[0072] In a feasible embodiment, the step of updating or improving the CNC machining compensation model based on the error variation law, the first machining error data, and the second machining error data includes:

[0073] S422: If the error variation law indicates that the error is affected by the nonlinear effect of tool wear, after constructing a linear compensation model based on the first machining error data and the second machining error data, a nonlinear correction is introduced into the linear compensation model to obtain the CNC machining compensation model.

[0074] The linear compensation model is: y1 = a0 + a1x

[0075] The nonlinear correction is: Δy = a²x 2 +a3x 3

[0076] The processing compensation model is: y = a0 + a1x + a2x 2 +a3x 3

[0077] Where y represents the final compensation amount, x represents the difference between the measured machining coordinate parameters and the theoretical coordinate machining parameters, and a0, a1, a2, and a3 represent the parameters of the compensation function to be obtained.

[0078] In a feasible embodiment, step S5: optimizing CNC machining parameters according to the CNC machining compensation model to drive the machining equipment to perform fine boring to remove the second machining error data and the third machining allowance includes:

[0079] S51: After performing the second semi-finishing, the radial distribution and axial dimension deviation of the third machining allowance are obtained by using the multi-point averaging method and measuring multiple sections with a digital micrometer.

[0080] Radial distribution and axial dimensional deviations can be used for tool compensation in subsequent precision boring, reducing the scrap rate.

[0081] S52: Based on the CNC machining compensation model, obtain the compensation coefficients for the CNC machining parameters;

[0082] S53: Optimize the CNC machining parameters for the third machining allowance based on the radial distribution, the axial dimension deviation, and the compensation coefficient, so as to perform fine boring to remove the third machining allowance.

[0083] In one feasible embodiment, the step of optimizing the CNC machining parameters for the third machining allowance includes:

[0084] Adjust the cutting speed to the material-compatible range to reduce thermal deformation, and / or adjust the feed rate, and / or reduce cutting force fluctuations.

[0085] In one feasible embodiment, the first machining allowance, the second machining allowance, and the third machining allowance are all 0.1 mm.

[0086] In summary, this application can be divided into three processing stages: "rough boring stage - semi-finish boring step-by-step iterative processing stage - finish boring closed-loop compensation processing stage".

[0087] In the rough boring stage, based on the differential analysis of workpiece material (such as aluminum alloy, high-strength steel), hole depth-to-diameter ratio (L / D), and number of steps, a boring tool with appropriate rigidity is selected. Simultaneously, a uniform machining allowance of 0.3mm is reserved in the continuous surface area at two heights. By "equal allowance distribution", the problem of sudden cutting force caused by uneven allowance in traditional processes is avoided, and the fluctuation range of form and position error is reduced to a controllable range. This not only reserves correction space for subsequent finishing but also ensures the stability of the cutting process. In addition, the rough machining is inspected by the machine probe or offline coordinate measuring machine to strictly constrain the cylindricity and coaxiality of the hole system after rough boring, ensuring that subsequent error correction is only aimed at the dimension of dimensional deviation, rather than form and position defects.

[0088] In the semi-finish boring step-by-step iterative machining stage, the error is accurately corrected through a closed-loop logic of "step-by-step cutting - real-time detection - iterative compensation". The specific process is as follows:

[0089] First, the 0.3mm machining allowance reserved after rough boring is divided into three equal parts (0.1mm each). This design is based on the tool stress deformation characteristics—the cutting depth and the tool radial deformation are non-linearly positively correlated. By controlling the single cutting depth (≤0.1mm), the tool stress state can be kept consistent at each stage, maintaining stable radial deformation and avoiding error fluctuations caused by sudden changes in stress in traditional large-step cutting. The deformation amount of traditional processes reaches 0.015mm, with an error fluctuation of ±0.03mm.

[0090] After removing the initial 0.1mm allowance using the first semi-finish boring, a high-precision laser diameter gauge (measurement accuracy ≤0.001mm) is used to inspect the dimensions of the stepped machining surface and obtain the actual dimensional parameter D. Based on the measured data, the machine tool positioning error (such as servo lag and lead screw pitch deviation) is analyzed by the difference between the program coordinates and the actual machining coordinate parameters. The tool wear is calculated by comparing the tool tip profile before and after cutting, and the temperature change during machining measured by the temperature measurement module is integrated to generate a comprehensive error value containing multi-source interference.

[0091] Based on the error analysis results, the error measurement module substitutes key parameters into the compensation formula, dynamically adjusting parameters such as the tool radius compensation value and feed rate in the CNC program. Then, a second semi-finishing process is performed to remove the second 0.1mm allowance. This process, through the synergistic effect of "small step-pitch cutting + data-driven compensation," reduces the dimensional error in the semi-finish boring stage compared to traditional processes, achieving a step-like convergence of errors and laying a core foundation for achieving the tolerance target of the final precision boring 54.

[0092] In the precision boring closed-loop compensation stage: the convergence of dimensional tolerances is achieved through closed-loop control of "high-precision measurement - dynamic modeling - precise compensation".

[0093] First, for the remaining 0.1mm allowance after the second semi-finishing, multiple sections were measured using the multi-point averaging method and a digital micrometer to obtain the radial distribution and axial dimensional deviation of the allowance. A "position-allowance" data matrix was established to ensure the visualization and quantification of the remaining machining amount.

[0094] Based on the error records of the previous two semi-finish boring operations (including machine tool positioning errors, tool wear, temperature coefficients, etc.), the least squares method is used to analyze the error variation law. If the error drifts linearly, a linear compensation model is established; if it is affected by the nonlinearity of tool wear, a nonlinear correction is introduced, and finally a dynamic error compensation model is constructed. This model is more adaptable than the static compensation in the semi-finish boring stage and can respond to fluctuations in the machining environment in real time. For example, sudden temperature changes or tool chipping.

[0095] Based on the compensation coefficients output by the dynamic model, the final machining parameters are optimized in multiple dimensions: the cutting speed is adjusted to the material matching range to reduce thermal deformation; the feed rate is reduced to a reasonable range to reduce cutting force fluctuations; and real-time compensation values ​​are written into the CNC system macro program, such as correcting tool offset in advance based on model predictions, and simultaneously correcting residual positioning errors and thermal errors.

[0096] During the final precision boring, a rigid-enhanced fine-tuning boring bar is used to remove the remaining 0.1mm allowance. A "low-speed constant feed" strategy is used to control the radial deformation of the tool, and a helical interpolation path is used to correct the roundness of the hole. During machining, the built-in probe monitors dimensional changes in real time. If the deviation from the preset threshold (e.g., ±0.005mm) is detected, parameter readjustment is immediately triggered to ensure dimensional stability at the cutting endpoint.

[0097] Ultimately, through the above process, the workpiece hole diameter size is stably converged to a reasonable tolerance range. Verification by coordinate measuring machine shows that the cylindricity and coaxiality fully meet the stringent requirements of high-end manufacturing for precision hole systems, and achieve "passing on the first pass" with a scrap rate reduced to 0.

[0098] Therefore, this application has the following effects:

[0099] Effect 1: Precise and Efficient Error Control: Through a three-stage process of "rough boring pre-control (step S1) - semi-finish boring step-by-step iteration (steps S2-S3) - finish boring closed-loop compensation (steps S4-S5)," stepwise convergence of errors is achieved. In the rough boring stage, uniform allowance and form and position error constraints lay a stable foundation for subsequent machining; semi-finish boring uses small step-pitch cutting combined with real-time detection and dynamic compensation, integrating multiple sources of interference such as machine tool positioning error, tool wear, and temperature changes, to significantly reduce dimensional errors; in the finish boring stage, a dynamic error compensation model is constructed, combined with real-time monitoring and parameter optimization, to respond to sudden situations (such as sudden temperature changes and tool micro-chipping), ultimately achieving precise convergence of dimensional tolerances and ensuring that cylindricity, coaxiality, and other form and position accuracy meet the standards.

[0100] Effect 2: Improved machining stability and consistency. Addressing the issue of large cutting force fluctuations in traditional methods, strategies such as differentiated tool selection, step-by-step uniform allowance (e.g., dividing a 0.3mm allowance into three equal parts), and "low-speed constant feed" control the radial deformation of the tool and reduce sudden changes in cutting force. Simultaneously, a multi-stage measurement and compensation mechanism can promptly correct deviations, prevent error accumulation, achieve "first-pass machining qualification," and reduce the scrap rate to 0.

[0101] Effect 3: Adaptability to complex working conditions and multi-source error coupling. The method comprehensively considers the differences in factors such as workpiece material, hole depth-to-diameter ratio, and number of steps, and reflects the specificity in tool selection and parameter settings; the error compensation model integrates multi-source errors such as machine tool, cutting tool, and temperature, and the dynamic model in the fine boring stage is more adaptable than static compensation, which can cope with real-time fluctuations in the machining environment and solve the problem of multi-source error coupling that is difficult to handle in traditional methods.

[0102] Effect 4: Balancing high efficiency and high precision. The three-stage process is clearly divided: rough boring quickly removes excess material, while semi-finish boring and finish boring focus on error correction, ensuring high precision while avoiding efficiency losses caused by over-machining. Through CNC system macro programs, helical interpolation paths, and other technologies, compensation parameters are quickly written and hole shape is corrected, balancing processing efficiency with the manufacturing requirements of precision hole systems.

[0103] Additionally, please see Figure 2 The step-by-step allowance iterative compensation and precise error control method for CNC boring in this application can achieve tool compensation through modules such as an error measurement module obtained from the feedback of a displacement sensor, a temperature sensor, a power supply module, and an industrial control computer module.

[0104] The measurement module first divides the machining length of the workpiece to be semi-finished and finished into three equal parts. The error measurement module measures the error of the workpiece after each machining operation on the CNC boring machine. The temperature measurement module measures the temperature during machining. The measured error values ​​and temperatures are fed back to the machining calculation module, which calculates tool compensation for subsequent machining operations. The 24V DC power module supplies power to the displacement measurement module and the industrial control computer module. The industrial control computer host module connects to the information acquisition modules of the displacement measurement module and the temperature measurement module to realize communication and debugging of the lower-level machine. The signal acquisition and control module communicates with the upper-level machine through the port to display temperature data, error data, and error compensation for the next stage.

[0105] The error measurement module mainly consists of a displacement error sensor, an encoder and feedback system, and a data acquisition and processing system. For workpieces with large aperture ratios and high precision, such as those machined on boring machines, a laser displacement sensor is used. Firstly, laser sensors offer high measurement accuracy and high precision control. Laser displacement sensors primarily measure the distance between the object's surface and the sensor using laser triangulation or interferometry. A laser beam is emitted and illuminates the surface of the object being measured; the laser point is reflected off the object's surface and focused onto a photodetector (CMOS). When the object moves, the position of the laser point on the photodetector shifts; by calculating the displacement of the laser point on the sensor (based on trigonometric relationships), the change in distance between the object and the sensor can be accurately determined. The diagram below shows the internal circuit principle of the laser sensor. The laser sensor is powered by a DC power supply with an input voltage of 24V. An internal amplifier circuit amplifies the analog voltage signal, converting it into a 0-5V voltage signal, which is then output to the signal acquisition and control module. The circuit diagram of the laser sensor is shown below. Figure 3 As shown.

[0106] The tool temperature acquisition module includes a temperature sensor, a signal conditioning and transmission unit, and an installation adapter structure. Its key feature is that the temperature sensing unit employs a high-temperature resistant thermocouple sensor, integrated into a miniature temperature measuring cavity at the tail of the boring machine tool holder. The measuring end of the thermocouple is directly coupled to the heat conduction path of the tool's cutting edge via thermally conductive silicone, while the reference end is fixed to the constant-temperature zone of the tool holder and isolated from the external environment through an insulating thermally conductive layer. Based on the Seebeck effect, the thermocouple sensor utilizes the closed loop formed by the tool material and the thermocouple alloy wire to convert the temperature difference between the high-temperature zone of the cutting edge and the reference end of the tool holder into a millivolt-level thermoelectric potential signal. The signal conditioning and transmission unit is integrated into a sealed cavity at the tail of the tool holder and includes: a cold junction compensation circuit: a high-precision temperature sensor is used to monitor the reference junction temperature in real time, and a microprocessor calculates the cold junction correction value of the thermocouple thermoelectric potential, and a lookup table method is used to complete the nonlinear correction; a differential amplifier module: the instrumentation amplifier differentially amplifies the weak 0-50mV signal output by the thermocouple, suppresses electromagnetic interference of the boring machine spindle, and outputs a 0-2.5V voltage signal.

[0107] The circuit diagram of the tool temperature acquisition module is as follows: Figure 4 As shown, Figure 4The P5 port is a four-wire PT100 interface; the AD623 is a rail-to-rail amplifier with R22 = 5K and a gain of G = (1 + 100 / 5) = 20 times; that is, the measured value of Vpin_in1 is the voltage across the PT100 amplified by 11 times; using another ADC sampling port PIN_IN2, the current flowing through the PT100 can be calculated from Vpin_in2 and R26 = 1K; the temperature coefficient of the PT100 resistor k = 0.385Ω / ℃; when its resistance R = 100℃, it indicates that the temperature is 0℃, and its resistance increases by 0.385Ω for every 1℃ increase.

[0108] The signal acquisition and control module mainly includes a DC power conversion module, an operational amplifier module, an A / D conversion module, a control module, and a serial communication module. The DC power conversion module converts DC power from one voltage level to another. The DC power conversion module designed in this invention mainly includes a boost DC power conversion module that can increase the DC voltage from 12V to a DC output voltage of 15V. The circuit diagram of the DC power conversion module is shown below. Figure 5 As shown.

[0109] The A / D conversion module uses the AD7656 as ADI's 6-channel synchronous sampling 16-bit successive approximation A / D converter. Its working process is divided into three steps: sampling and holding, analog-to-digital conversion, and data output.

[0110] During the sampling and holding phase, six independent low-noise sample-and-hold amplifiers can synchronously sample six analog signals. Upon external triggering, they simultaneously enter the holding state, handling input frequencies up to 8MHz and true bipolar input signals of ±10V / ±5V, ensuring stable holding of multiple channels simultaneously. In the analog-to-digital conversion phase, each channel uses a successive approximation architecture, starting from the most significant bit, and converts the held analog signal into a 16-bit digital signal through 16 comparison cycles. The conversion is indicated by a BUSY signal, with a typical conversion time of 4μs and a sampling rate of 250kSPS, guaranteeing high conversion accuracy. In the data output phase, both parallel and serial (SPI compatible) modes are supported. Parallel mode achieves fast single-cycle transmission via a 16-bit data bus, while serial mode follows the SPI protocol, transmitting bit-by-bit through a single pin at a clock frequency of up to 30MHz, suitable for scenarios with multi-channel synchronous sampling and high input frequency processing requirements.

[0111] The control module primarily utilizes a microcontroller. The STM32L431RCT6 was selected as the microcontroller control chip. This chip is a 32-bit microcontroller based on the ARM Cortex-M4 core, characterized by low power consumption and high performance. It has 64 pins, including power, reset, clock, and boot pins. The remaining pins can be flexibly configured as general-purpose input / output ports (GPIO) or reused for various peripheral functions such as SPI, I2C, and USART. The chip's main features are particularly prominent. Its high-performance Cortex-M4 core includes a floating-point unit, enabling efficient handling of complex mathematical operations and data processing tasks, meeting high-precision data processing requirements. It boasts abundant memory resources, with built-in flash memory and SRAM, providing ample space for program storage and data caching. In terms of power consumption, it features multiple low-power modes that can be flexibly adjusted according to different application scenarios, effectively reducing system energy consumption and extending device battery life. Furthermore, it supports multiple communication protocols, facilitating data interaction with various peripherals, and possesses rich development tools and library functions, enabling developers to quickly develop and debug. Since the AD7606 uses the SPI protocol for communication in serial mode, connecting the STM32L431RCT6 and the AD7606 via the SPI interface is a suitable choice.

[0112] Write a C program to calibrate and compensate the digital signal processed by the AD7606. First, define relevant variables in the program to store the raw data, calibration parameters, and processed results. After reading the digital signal output by the AD7606, combine it with the sensor's calibration data, such as zero-point offset and sensitivity coefficient, to calibrate the raw data and eliminate system errors.

[0113] Industrial PC Components: An industrial PC mainly consists of the following parts: processor, motherboard, storage device, chassis, and power supply.

[0114] The processor uses an Intel Core high-performance processor, providing ample computing power for industrial control software operation through a multi-core parallel computing architecture. The motherboard adopts a multi-layer printed circuit board design, enhancing mechanical strength and electromagnetic interference resistance through physical isolation between the signal layer and power layer. It integrates industrial control bus interfaces such as digital I / O, CAN, and RS485, as well as Ethernet and USB universal communication interfaces to adapt to various types of peripheral connections. The storage device includes a solid-state drive (SSD) and random access memory (RAM). The SSD utilizes flash memory for high-speed data read / write and vibration-resistant storage, while the 16GB RAM meets the memory space requirements for complex control software operation. The power module adopts a 24V DC power supply scheme and integrates overvoltage / overcurrent / undervoltage protection circuits to adapt to industrial field power environments.

[0115] The device embodiments described above are merely illustrative. The components described as separate parts may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this application according to actual testing needs. Those skilled in the art can understand and implement this without any inventive effort.

[0116] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0117] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 The computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function selected in one or more boxes.

[0118] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function selected in one or more boxes.

[0119] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0120] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0121] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0122] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0123] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for step-by-step allowance iterative compensation and precise error control in CNC boring, characterized in that, include: During rough boring of a hole, an initial machining allowance is reserved in a continuous surface area with two heights; the initial machining allowance includes a first machining allowance, a second machining allowance, and a third machining allowance; Based on the first semi-finish boring performed by the driving machining equipment, the first machining error data is analyzed and obtained; Based on the first processing error data, processing compensation data is obtained, and the processing equipment is driven to perform a second semi-finishing based on the processing compensation data, the first processing error data and the second processing allowance, so as to obtain the equipment performing the second semi-finishing data. Based on the first and second machining error data, a CNC machining compensation model is constructed. The CNC machining parameters are optimized according to the CNC machining compensation model to drive the machining equipment to perform fine boring to remove the second machining error data and the third machining allowance.

2. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to claim 1, characterized in that, The step of analyzing and obtaining the first machining error data by performing the first semi-finish boring based on the driving machining equipment includes: After the driving processing equipment executes the process, the dimensions of the processed surface are measured by a high-precision laser diameter measuring instrument to obtain the measured processing coordinate parameters. The machine tool positioning error is obtained by comparing the measured machining coordinate parameters with the coordinates based on CNC machining theory. Based on the machine tool positioning error, the comparison of the tool tip profile before and after cutting to calculate the tool wear, and the temperature change data during machining, a first machining error data containing multi-source interference is generated.

3. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to claim 2, characterized in that, Based on the first machining error data, the step of obtaining machining compensation data, and driving the machining equipment to perform a second semi-finishing based on the machining compensation data, the first machining error data, and the second machining allowance, to obtain the data for the equipment to perform the second semi-finishing, includes: A CNC machining compensation model is constructed based on the first machining error data; Machining compensation data is obtained based on the CNC machining compensation model; the machining compensation data includes at least the tool radius compensation value and the feed rate. Based on the first machining error data, the second machining allowance, and the machining compensation data, the machining equipment is driven to perform a second semi-finishing process to obtain the second machining error data of the machining equipment performing the second semi-finishing process.

4. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to any one of claims 1-3, characterized in that, The step of constructing a CNC machining compensation model based on the first machining error data and the second machining error data includes: Based on the first machining error data and the second machining error data, the least squares method is used to analyze the error variation law. The difference between the theoretical value programmed for the first CNC boring machining and the actual measured value is expressed as the first machining error. Similarly, the difference between the theoretical value programmed for the second CNC machining and the actual measured value is expressed as the second machining error. Based on the error variation pattern, the first machining error data, and the second machining error data, the CNC machining compensation model is updated or improved.

5. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to claim 4, characterized in that, The steps for updating or improving the CNC machining compensation model based on the error variation pattern, the first machining error data, and the second machining error data include: If the error variation pattern indicates that the error drifts linearly, a linear compensation model is constructed based on the first machining error data and the second machining error data as the CNC machining compensation model.

6. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to claim 5, characterized in that, The steps for updating or improving the CNC machining compensation model based on the error variation pattern, the first machining error data, and the second machining error data include: If the error variation pattern indicates that the error is affected by the nonlinear effect of tool wear, after constructing a linear compensation model based on the first machining error data and the second machining error data, a nonlinear correction is introduced into the linear compensation model to obtain the CNC machining compensation model.

7. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to claim 5, characterized in that, The CNC machining compensation model is shown in the following formula: D 补偿 =(D 实测 -D 理论 )×k 温度系数 +d 刀具磨损 Where, Δ 补偿 D is the compensation coefficient. 实测 For the actual machining coordinate parameters, D 理论 For theoretical coordinates, k 温度系数 For temperature variation data during processing, δ 刀具磨损 This is the tool wear data during machining.

8. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to claim 7, characterized in that, The steps include: After performing the second semi-finishing, the radial distribution and axial dimensional deviation of the third machining allowance are obtained by using the multi-point averaging method and measuring multiple sections with a digital micrometer. Based on the CNC machining compensation model, obtain the compensation coefficients for the CNC machining parameters; The CNC machining parameters for the third machining allowance are optimized based on the radial distribution, the axial dimensional deviation, and the compensation coefficient, so as to perform fine boring to remove the third machining allowance.

9. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to claim 8, characterized in that, The steps for optimizing the CNC machining parameters for the third machining allowance include: Adjust the cutting speed to the material-compatible range to reduce thermal deformation, and / or adjust the feed rate, and / or reduce cutting force fluctuations.

10. The method for step-by-step allowance iterative compensation and precise error control in CNC boring machining according to claim 1, characterized in that, The first machining allowance, the second machining allowance, and the third machining allowance are all 0.1 mm.

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