Spindle thermal elongation dynamic compensation method and system for five-axis machine tools

Abstract

The present invention provides a method and system for dynamic compensation of spindle thermal elongation for a five-axis machine tool, comprising steps S1: obtaining an electrical signal of the spindle's internal axial elongation measured in real time by a displacement sensor installed inside the spindle, and converting the electrical signal output by the displacement sensor into a displacement signal; S2: converting the axial elongation measured by the spindle's internal displacement sensor into the spindle's external axial elongation based on the displacement signal in S1; S3: calculating a spindle external elongation compensation value based on the spindle's external axial elongation in S2, and decomposing the spindle external elongation compensation value into compensation components for each axis of the machine tool; and S4: implementing dynamic compensation for spindle thermal elongation. The method calculates the spindle's external axial thermal elongation using the spindle's internal displacement sensor's measurement value, and decomposes the spindle thermal elongation compensation value into compensation components for each axis according to the machine tool's coordinate system. This solves the problem of dynamic compensation for each axis, improves the accuracy of spindle elongation compensation, and is suitable for five-axis machine tools.

Description

Technical Field

[0001] The present invention relates to the technical field of five-axis machine tool control, and in particular to a method and system for dynamic compensation of thermal elongation of a spindle of a five-axis machine tool. Background Art

[0002] During high-speed rotation, the spindle temperature of a five-axis machine tool gradually rises, causing thermal expansion and elongation. Current methods for compensating for spindle thermal expansion primarily rely on installing a temperature sensor on the spindle. Through extensive experiments, a model is established to model the relationship between spindle temperature and elongation, which is then used to calculate the compensation amount. However, this method only considers compensation in a single axial direction, and the accuracy of this method is significantly affected by the temperature sensor's installation location.

[0003] The existing Chinese patent application document with publication number CN113695970B discloses a method for compensating for thermal elongation caused by temperature rise of a milling machine spindle, comprising the following steps: first, starting a run-in process from a cold machine state, and collecting temperature data and thermal elongation data, using a temperature sensor to detect the temperature data at the current milling machine spindle speed in real time, and at the same time, using a tool setter to detect the spindle thermal elongation data under the current temperature data; then, using a controller to capture the temperature data and spindle thermal elongation data during the run-in process to establish a relationship model between the two; finally, using the established relationship model, the current thermal elongation is calculated based on the real-time temperature data of the machine tool to perform compensation.

[0004] The existing method for compensating for thermal elongation caused by spindle temperature rise calculates the compensation value by establishing a relationship between the spindle temperature and the elongation. The calculation result is affected by the installation position of the temperature sensor, the compensation accuracy is low, and its calculation model only considers the Z-axis direction, which is not applicable to five-axis machine tools. Summary of the Invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a method and system for dynamic compensation of thermal elongation of a spindle of a five-axis machine tool.

[0006] According to the present invention, a method for dynamic compensation of thermal elongation of a spindle of a five-axis machine tool is provided, comprising the following steps:

[0007] S1, obtaining an electrical signal of the axial elongation of the spindle measured in real time by a displacement sensor installed inside the spindle, and converting the electrical signal output by the displacement sensor into a displacement signal;

[0008] S2, converting the axial extension measured by the internal displacement sensor of the spindle into the external axial extension of the spindle according to the displacement signal in S1;

[0009] S3. Calculate the spindle external elongation compensation value based on the spindle external axial elongation in S2, and decompose the spindle external elongation compensation value into compensation components for each axis of the machine tool;

[0010] S4. Realize dynamic compensation for thermal expansion of the spindle.

[0011] Preferably, for step S1, the mathematical relationship between the electrical signal output by the displacement sensor and the displacement is as follows:

[0012] D=aU+b;

[0013] Wherein, D represents the internal axial extension of the spindle detected by the displacement sensor, U represents the electrical signal output by the displacement sensor, and a and b are constants determined by the characteristics of sensors of different specifications.

[0014] Preferably, for S2, the mathematical relationship between the internal axial extension of the spindle detected by the internal displacement sensor of the spindle and the external axial extension of the spindle is:

[0015] f(x)=cx+d;

[0016] Where x represents the internal axial extension of the spindle measured by the displacement sensor, f(x) represents the external axial extension of the spindle, and c and d are calculated after calibrating the internal axial thermal extension of the spindle.

[0017] Preferably, the calibration process for the internal axial thermal elongation of the spindle is as follows:

[0018] The internal extension x and external extension y of the spindle are measured from the initial state of the spindle, and the measurement is stopped when the spindle temperature reaches a steady state. A total of n sets of data (xi,yi) are measured, i=0,1,2,...,n-1;

[0019] Use the least squares method to perform linear fitting on the n sets of measured data and substitute the n sets of data into the following equation:

[0020]

[0021] Calculate the values ​​of c and d.

[0022] Preferably, for step S3, the difference between the external axial extension of the spindle and the reference value of the spindle extension in the initial state of the machine tool is calculated to obtain the external extension compensation value of the spindle, and the external extension compensation value of the spindle is decomposed into compensation components of each axis according to the five-axis machine tool coordinate system.

[0023] Preferably, the method comprises the following steps:

[0024] S1.1. Obtain an electrical signal of the axial elongation of the spindle measured in real time by a displacement sensor installed inside the spindle, and convert the electrical signal output by the displacement sensor into a displacement signal;

[0025] S1.2. Determine whether the axial extension inside the spindle reaches the compensation trigger threshold. If so, proceed to step S2.1. If not, proceed to the machining program.

[0026] S2.1. Convert the axial extension measured by the internal displacement sensor of the spindle into the external axial extension of the spindle according to the displacement signal in S1.1.

[0027] S2.2. Determine whether the spindle's external axial extension is less than the software limit. If so, proceed to step S3.1. If not, use the software limit as the extension and proceed to step S3.1.

[0028] S3.1. Obtain the coordinate values ​​of each axis of the five-axis machine tool;

[0029] S3.2. Calculate the spindle external elongation compensation value and decompose the spindle external elongation compensation value into compensation components for each axis of the machine tool;

[0030] S4.1. Perform dynamic compensation for thermal expansion of the spindle;

[0031] S4.2. If the dynamic compensation fails to trigger an alarm, the process ends; if the dynamic compensation is successful, the processing program begins;

[0032] S4.3: If the processing program is finished, the process ends. If the processing program is not finished, return to step S1.1.

[0033] According to the present invention, a dynamic compensation system for thermal expansion of a spindle of a five-axis machine tool is provided, the compensation system comprising:

[0034] The first module: obtains the electrical signal of the axial elongation inside the spindle measured in real time by a displacement sensor installed inside the spindle, and converts the electrical signal output by the displacement sensor into a displacement signal;

[0035] The second module: according to the displacement signal in S1, the axial extension measured by the internal displacement sensor of the spindle is converted into the external axial extension of the spindle;

[0036] The third module: according to the spindle external axial elongation in S2, the spindle external elongation compensation value is calculated, and the spindle external elongation compensation value is decomposed into the compensation components of each axis of the machine tool;

[0037] Module 4: Realize dynamic compensation for thermal expansion of the spindle.

[0038] Preferably, the first module includes a PLC analog input module, which converts the received electrical signal output by the sensor into a displacement signal according to the following formula:

[0039] D=aU+b;

[0040] Wherein, D represents the internal axial extension of the spindle detected by the displacement sensor, U represents the electrical signal output by the displacement sensor, and a and b are constants determined by the characteristics of sensors of different specifications.

[0041] Preferably, the third module saves the reference value of the spindle extension in the initial state of the machine tool in the control system, calculates the difference between the spindle external axial extension and the reference value of the spindle extension in the initial state of the machine tool, and obtains the spindle external extension compensation value.

[0042] Preferably, the first module includes:

[0043] The first submodule is used to obtain an electrical signal of the axial extension of the spindle measured in real time by a displacement sensor installed inside the spindle, and convert the electrical signal output by the displacement sensor into a displacement signal;

[0044] The second submodule: determines whether the axial extension inside the spindle reaches the compensation trigger threshold. If so, the process enters the third submodule. If not, the process enters the machining program.

[0045] The second module includes:

[0046] The third submodule: converts the axial extension measured by the internal displacement sensor of the spindle into the external axial extension of the spindle according to the displacement signal in the first submodule;

[0047] The fourth submodule: determines whether the external axial extension of the spindle is less than the software limit. If so, the process proceeds to the fifth submodule. If not, the process takes the software limit as the extension and proceeds to the fifth submodule.

[0048] The third module includes:

[0049] The fifth submodule: obtains the coordinate values ​​of each axis of the five-axis machine tool;

[0050] The sixth submodule: calculates the spindle external elongation compensation value and decomposes the spindle external elongation compensation value into compensation components of each axis of the machine tool;

[0051] The fourth module includes:

[0052] The seventh submodule: dynamic compensation for thermal expansion of the spindle;

[0053] The eighth submodule: If the dynamic compensation fails to trigger the alarm information process ends; if the dynamic compensation is successful, enter the processing program;

[0054] Ninth submodule: If the processing program ends, the process ends; if the processing program does not end, return to the first submodule.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1. The present invention measures the internal thermal elongation of the spindle in real time by installing a displacement sensor inside the spindle and adopts a method of calibration between the internal displacement sensor of the spindle and the external axial elongation, thereby solving the problem of calculating the external axial thermal elongation of the spindle using the measurement value of the internal displacement sensor of the spindle. The thermal elongation compensation of the spindle is then decomposed into compensation components for each axis according to the machine tool coordinate system, thereby solving the problem of dynamic compensation for each axis, helping to improve the accuracy of spindle elongation compensation, and is suitable for five-axis machine tools.

[0057] 2. The present invention sets a compensation trigger threshold. When the internal elongation of the spindle detected by the displacement sensor reaches the compensation trigger threshold, compensation is performed, which helps to improve the compatibility of the compensation system with the five-axis machine tool.

[0058] 3. The present invention helps to ensure the yield rate of five-axis machine tool production by setting an alarm message triggered by dynamic compensation failure and ending the work process. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0060] Figure 1 This is a flow chart of a method for dynamic compensation of thermal elongation of a spindle of a five-axis machine tool according to a first embodiment of the present invention;

[0061] Figure 2 This is a flow chart of a method for dynamic compensation of thermal elongation of a spindle of a five-axis machine tool in the second embodiment of the present invention. DETAILED DESCRIPTION

[0062] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0063] Example 1

[0064] like Figure 1As shown, a method and system for dynamic compensation of thermal elongation of a spindle for a five-axis machine tool provided by the present invention include a method for dynamic compensation of thermal elongation of a spindle for a five-axis machine tool, comprising the following steps:

[0065] S1. Obtain an electrical signal of the axial elongation inside the main shaft measured in real time by a displacement sensor installed inside the main shaft, and convert the electrical signal output by the displacement sensor into a displacement signal.

[0066] Specifically, the mathematical relationship between the electrical signal output by the displacement sensor and the displacement is as follows:

[0067] D=aU+b;

[0068] Wherein, D represents the internal axial extension of the spindle detected by the displacement sensor, U represents the electrical signal output by the displacement sensor, and a and b are constants determined by the characteristics of sensors of different specifications.

[0069] S2. According to the displacement signal in S1, the axial extension measured by the internal displacement sensor of the spindle is converted into the external axial extension of the spindle.

[0070] Specifically, the mathematical relationship between the internal axial extension of the spindle detected by the internal displacement sensor of the spindle and the external axial extension of the spindle is:

[0071] f(x)=cx+d;

[0072] Where x represents the internal axial extension of the spindle measured by the displacement sensor, f(x) represents the external axial extension of the spindle, and c and d are calculated after calibrating the internal axial thermal extension of the spindle.

[0073] The calibration process for the internal axial thermal expansion of the spindle is as follows:

[0074] The internal extension x and external extension y of the spindle are measured from the initial state of the spindle, and the measurement is stopped when the spindle temperature reaches a steady state. A total of n sets of data (xi,yi) are measured, i=0,1,2,...,n-1;

[0075] Use the least squares method to perform linear fitting on the n sets of measured data and substitute the n sets of data into the following equation:

[0076]

[0077] Calculate the values ​​of c and d.

[0078] S3. According to the external axial extension of the spindle in S2, a compensation value of the external extension of the spindle is calculated, and the compensation value of the external extension of the spindle is decomposed into compensation components of each axis of the machine tool.

[0079] Specifically, the difference between the spindle external axial elongation and the spindle elongation reference value in the initial state of the machine tool is calculated to obtain the spindle external elongation compensation value, and the spindle external elongation compensation value is decomposed into compensation components of each axis according to the five-axis machine tool coordinate system.

[0080] S4. Implement dynamic compensation for the thermal expansion of the spindle. Specifically, the compensation software sends the compensation components of each axis to the control system to implement the spindle thermal expansion compensation function.

[0081] This application also proposes a spindle thermal expansion dynamic compensation system for a five-axis machine tool, the compensation system comprising:

[0082] The first module: obtains the electrical signal of the axial elongation inside the main shaft measured in real time by the displacement sensor installed inside the main shaft, and converts the electrical signal output by the displacement sensor into a displacement signal.

[0083] The first module includes a PLC analog input module, which converts the received electrical signal output by the sensor into a displacement signal according to the following formula.

[0084] D=aU+b;

[0085] Wherein, D represents the internal axial extension of the spindle detected by the displacement sensor, U represents the electrical signal output by the displacement sensor, and a and b are constants determined by the characteristics of sensors of different specifications.

[0086] The second module: According to the displacement signal in S1, the axial extension measured by the internal displacement sensor of the spindle is converted into the external axial extension of the spindle.

[0087] The third module: According to the spindle external axial elongation in S2, the spindle external elongation compensation value is calculated, and the spindle external elongation compensation value is decomposed into compensation components of each axis of the machine tool.

[0088] The third module saves the reference value of the spindle extension in the initial state of the machine tool in the control system, calculates the difference between the spindle external axial extension and the reference value of the spindle extension in the initial state of the machine tool, and obtains the spindle external extension compensation value.

[0089] Module 4: Realize dynamic compensation for thermal expansion of the spindle.

[0090] Example 2

[0091] like Figure 2 As shown, based on the first embodiment, a method and system for dynamic compensation of thermal elongation of a spindle for a five-axis machine tool provided by the present invention include a method for dynamic compensation of thermal elongation of a spindle for a five-axis machine tool, comprising the following steps:

[0092] S1.1. Obtain an electrical signal of the axial extension of the spindle measured in real time by a displacement sensor installed inside the spindle, and convert the electrical signal output by the displacement sensor into a displacement signal.

[0093] S1.2. Determine whether the axial extension inside the spindle reaches the compensation trigger threshold. If so, proceed to step S2.1. If not, proceed to the machining program.

[0094] S2.1. According to the displacement signal in S1.1, the axial extension measured by the internal displacement sensor of the spindle is converted into the external axial extension of the spindle.

[0095] S2.2. Determine whether the external axial extension of the spindle is less than the software limit. If so, proceed to step S3.1. If not, take the software limit as the extension and proceed to step S3.1.

[0096] S3.1. Obtain the coordinate values ​​of each axis of the five-axis machine tool.

[0097] S3.2. Calculate the spindle external elongation compensation value and decompose the spindle external elongation compensation value into compensation components for each axis of the machine tool.

[0098] S4.1. Perform dynamic compensation for the thermal expansion of the spindle.

[0099] S4.2. If the dynamic compensation fails to trigger an alarm, the process ends; if the dynamic compensation is successful, the processing program begins.

[0100] S4.3: If the processing program is finished, the process ends. If the processing program is not finished, return to step S1.1.

[0101] The present application also provides a spindle thermal expansion dynamic compensation system for a five-axis machine tool, the compensation system comprising:

[0102] The first module includes:

[0103] The first submodule is to obtain the electrical signal of the axial extension inside the main shaft measured in real time by the displacement sensor installed inside the main shaft, and convert the electrical signal output by the displacement sensor into a displacement signal.

[0104] The second submodule: determines whether the axial extension inside the spindle reaches the compensation trigger threshold. If it reaches the compensation trigger threshold, it enters the third submodule. If it does not reach the compensation trigger threshold, it enters the machining program.

[0105] The second module includes:

[0106] The third submodule: according to the displacement signal in the first submodule, the axial extension measured by the internal displacement sensor of the spindle is converted into the external axial extension of the spindle.

[0107] The fourth submodule: determines whether the external axial extension of the spindle is less than the software limit. If it is less than the software limit, enter the fifth submodule. If it is not less than the software limit, use the software limit as the extension and enter the fifth submodule.

[0108] The third module includes:

[0109] The fifth submodule: obtains the coordinate values ​​of each axis of the five-axis machine tool.

[0110] The sixth submodule: calculates the spindle external elongation compensation value and decomposes the spindle external elongation compensation value into compensation components of each axis of the machine tool.

[0111] The fourth module includes:

[0112] The seventh submodule: dynamic compensation of the thermal expansion of the spindle.

[0113] The eighth submodule: If the dynamic compensation fails to trigger an alarm, the process ends; if the dynamic compensation is successful, the processing program is entered.

[0114] Ninth submodule: If the processing program ends, the process ends; if the processing program does not end, return to the first submodule.

[0115] Example 3

[0116] Based on Example 1 and / or Example 2, a method for dynamic compensation of thermal elongation of a spindle for a five-axis machine tool provided by the present invention includes: installing a displacement sensor inside the spindle to measure the axial elongation of the spindle in real time. The output signal of the internal displacement sensor of the spindle is transmitted to an analog input module of a PLC. The electrical signal output by the displacement sensor is generally approximately linearly related to the displacement. The mathematical relationship between the electrical signal and the displacement is as follows:

[0117] D=aU+b;

[0118] Where D represents the spindle's internal displacement as detected by the displacement sensor, and U represents the electrical signal output by the displacement sensor. a and b are constants determined by the characteristics of different sensor specifications. When the displacement sensor detects elongation within the spindle, it sends an electrical signal corresponding to the elongation to the PLC. The PLC program then converts the received sensor signal into the spindle's internal elongation using the above formula.

[0119] The relationship between the internal displacement sensor of the spindle and the actual external extension of the spindle can be approximated by the following linear relationship:

[0120] f(x)=cx+d;

[0121] Where x represents the internal elongation of the spindle measured by the displacement sensor, f(x) represents the actual external elongation of the spindle, and c and d need to be calculated after calibrating the internal axial thermal elongation of the spindle.

[0122] The calibration process for the internal axial thermal elongation of the spindle is as follows:

[0123] 1) Starting from the initial state of the spindle, measure the internal elongation x and the external elongation y of the spindle, and stop measuring when the spindle temperature reaches a steady state. Measure n sets of data (xi,yi) in total, i = 0, 1, 2, ..., n-1.

[0124] 2) Substitute the measured n sets of data into the following formula to calculate c and d.

[0125]

[0126] 3) Using the calculated c and d values, determine the mathematical model between the external axial extension of the spindle and the axial extension measured by the internal displacement sensor.

[0127] The control system software stores the baseline value of the machine tool's initial spindle elongation. The compensation software reads the spindle's internal axial elongation from the PLC, converts it into spindle thermal elongation compensation through algorithmic processing, and sends the compensation value to the control system variables. When the control system software background program is running, it reads the spindle thermal elongation compensation value from the system variables and then decomposes it into compensation components for each axis based on the five-axis machine tool's coordinate system. These compensation components for each axis are then sent to the control system, achieving dynamic compensation for the five-axis machine tool's spindle thermal elongation.

[0128] The spindle thermal elongation compensation process is as follows:

[0129] 1)PLC reads the electrical signal of the displacement sensor inside the spindle.

[0130] 2) The PLC converts the electrical signal of the displacement sensor into displacement and stores it in the register.

[0131] 3) The compensation software reads the internal thermal expansion of the spindle from the PLC register.

[0132] 4) The compensation software takes the internal thermal expansion of the spindle as an input parameter and calculates the compensation value of the external thermal expansion of the spindle.

[0133] 5) The compensation software decomposes the spindle external thermal expansion compensation value into compensation components for each axis of the machine tool.

[0134] 6) The compensation software sends the compensation components of each axis to the control system to realize the spindle thermal expansion compensation function.

[0135] Those skilled in the art will appreciate that, in addition to implementing the system and its various devices, modules, and units provided by the present invention in purely computer-readable program code, it is entirely possible to implement the same functions of the system and its various devices, modules, and units provided by the present invention in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; the devices, modules, and units for implementing various functions can also be considered as both software modules implementing the method and structures within the hardware component.

[0136] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0137] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A method for dynamic compensation of thermal elongation of a spindle of a five-axis machine tool, characterized in that: The steps include: S1, obtaining an electrical signal of the axial elongation of the spindle measured in real time by a displacement sensor installed inside the spindle, and converting the electrical signal output by the displacement sensor into a displacement signal; S2, converting the axial extension measured by the internal displacement sensor of the spindle into the external axial extension of the spindle according to the displacement signal in S1; S3. Calculate the spindle external elongation compensation value based on the spindle external axial elongation in S2, and decompose the spindle external elongation compensation value into compensation components for each axis of the machine tool; S4, realize dynamic compensation for thermal elongation of the spindle; The step S1 comprises: S1.

1. Obtain an electrical signal of the axial elongation of the spindle measured in real time by a displacement sensor installed inside the spindle, and convert the electrical signal output by the displacement sensor into a displacement signal; S1.

2. Determine whether the axial extension inside the spindle reaches the compensation trigger threshold. If so, proceed to step S2.

1. If not, proceed to the machining program. The step S2 comprises: S2.

1. Convert the axial extension measured by the internal displacement sensor of the spindle into the external axial extension of the spindle according to the displacement signal in S1.

1. S2.

2. Determine whether the spindle's external axial extension is less than the software limit. If so, proceed to step S3. If not, use the software limit as the extension and proceed to step S3. For S2, the mathematical relationship between the internal axial extension of the spindle detected by the internal displacement sensor of the spindle and the external axial extension of the spindle is: f(x)=cx+d; Where x represents the internal axial extension of the spindle measured by the displacement sensor, f(x) represents the external axial extension of the spindle, and c and d are calculated after calibrating the internal axial thermal extension of the spindle. The calibration process for the internal axial thermal expansion of the spindle is as follows: The internal extension x and external extension y of the spindle are measured from the initial state of the spindle, and the measurement is stopped when the spindle temperature reaches a steady state. A total of n sets of data (xi,yi) are measured, i=0,1,2,...,n-1; Use the least squares method to perform linear fitting on the n sets of measured data and substitute the n sets of data into the following equation: Calculate the values ​​of c and d.

2. The method for dynamic compensation of thermal expansion of a spindle of a five-axis machine tool according to claim 1, wherein: For step S1, the mathematical relationship between the electrical signal output by the displacement sensor and the displacement is as follows: D=aU+b; Wherein, D represents the internal axial extension of the spindle detected by the displacement sensor, U represents the electrical signal output by the displacement sensor, and a and b are constants determined by the characteristics of sensors of different specifications.

3. The method for dynamic compensation of thermal expansion of a spindle of a five-axis machine tool according to claim 1, wherein: For step S3, the difference between the spindle external axial extension and the spindle extension reference value in the initial state of the machine tool is calculated to obtain the spindle external extension compensation value, and the spindle external extension compensation value is decomposed into compensation components of each axis according to the five-axis machine tool coordinate system.

4. The method for dynamic compensation of thermal expansion of a spindle of a five-axis machine tool according to claim 1, wherein: The steps include: S3.

1. Obtain the coordinate values ​​of each axis of the five-axis machine tool; S3.

2. Calculate the spindle external elongation compensation value and decompose the spindle external elongation compensation value into compensation components for each axis of the machine tool; S4.

1. Perform dynamic compensation for thermal expansion of the spindle; S4.

2. If dynamic compensation fails to trigger an alarm, the process ends; If dynamic compensation is successful, enter the processing program; S4.3: If the processing program is finished, the process ends. If the processing program is not finished, return to step S1.

1.

5. A dynamic compensation system for the thermal expansion of a spindle of a five-axis machine tool, characterized in that: The method for dynamic compensation of thermal elongation of a spindle of a five-axis machine tool according to any one of claims 1 to 4 is adopted, wherein the compensation system comprises: The first module: obtains the electrical signal of the axial elongation inside the spindle measured in real time by a displacement sensor installed inside the spindle, and converts the electrical signal output by the displacement sensor into a displacement signal; The second module: according to the displacement signal in S1, the axial extension measured by the internal displacement sensor of the spindle is converted into the external axial extension of the spindle; The third module: according to the spindle external axial elongation in S2, the spindle external elongation compensation value is calculated, and the spindle external elongation compensation value is decomposed into the compensation components of each axis of the machine tool; Module 4: Realize dynamic compensation for thermal expansion of the spindle; The first module includes: The first submodule is used to obtain an electrical signal of the axial extension of the spindle measured in real time by a displacement sensor installed inside the spindle, and convert the electrical signal output by the displacement sensor into a displacement signal; The second submodule: determines whether the axial extension inside the spindle reaches the compensation trigger threshold. If so, the process enters the third submodule. If not, the process enters the machining program. The second module includes: The third submodule converts the axial extension measured by the internal displacement sensor of the spindle into the external axial extension of the spindle according to the displacement signal in the first submodule; The fourth submodule: determines whether the external axial extension of the spindle is less than the software limit. If it is less than the software limit, enter the fifth submodule. If it is not less than the software limit, use the software limit as the extension and enter the third module.

6. The spindle thermal expansion dynamic compensation system for a five-axis machine tool according to claim 5, characterized in that: The first module includes a PLC analog input module, which converts the electrical signal output by the received sensor into a displacement signal according to the following formula: D=aU+b; Wherein, D represents the internal axial extension of the spindle detected by the displacement sensor, U represents the electrical signal output by the displacement sensor, and a and b are constants determined by the characteristics of sensors of different specifications.

7. The spindle thermal expansion dynamic compensation system for a five-axis machine tool according to claim 5, characterized in that: The third module saves the reference value of the spindle extension in the initial state of the machine tool in the control system, calculates the difference between the spindle external axial extension and the reference value of the spindle extension in the initial state of the machine tool, and obtains the spindle external extension compensation value.

8. The spindle thermal expansion dynamic compensation system for a five-axis machine tool according to claim 5, characterized in that: The third module includes: The fifth submodule: obtains the coordinate values ​​of each axis of the five-axis machine tool; The sixth submodule: calculates the spindle external elongation compensation value and decomposes the spindle external elongation compensation value into compensation components of each axis of the machine tool; The fourth module includes: The seventh submodule: dynamic compensation for thermal expansion of the spindle; The eighth submodule: If the dynamic compensation fails to trigger the alarm information process ends; if the dynamic compensation is successful, enter the processing program; Ninth submodule: If the processing program ends, the process ends; if the processing program does not end, return to the first submodule.

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