High-speed compensation system and method for machine tools based on laser interference principle

Abstract

A high-speed compensation system and compensation method for a machine tool based on the principle of laser interference, comprising a trigger collection module, a laser interferometry module, a data analysis and compensation module, and a communication module. The trigger collection module receives a trigger collection command, converts an encoder position value into a pulse value and transmits it to the laser interferometry module, retrieves parameter information and compensation point information of each axis of the machine tool in the numerical control system, and generates a machine tool operation code and a measurement preparation signal. The laser interferometry module receives the measurement preparation signal and the pulse value to obtain error data, environmental data, and expansion compensation values. The data analysis and compensation module collects error data, environmental data, and expansion compensation values, performs analysis processing to obtain accuracy parameters and compensation parameters, and transmits them to the numerical control system via the communication module. The laser interferometry device and the trigger collection device are used to measure machine accuracy, and the measurement efficiency is higher, and the measurement accuracy is more accurate and faster.

Description

[Technical field]

[0001] The present invention relates to the field of numerically controlled machine tools, and in particular to a high-speed compensation system and compensation method for machine tools based on the principle of laser interference. [Background technology]

[0002] At present, the measurement and compensation device of the existing machine tool needs to be installed outside the machine tool, and it is necessary to add a power supply and install an auxiliary device, and the operator needs to repeatedly adjust the light. In addition, the operator needs to set the relevant parameters of the machine tool and the relevant parameters for compensation, add and generate the process of the machine tool, and transmit the compensation parameters manually or through the storage device. The measurement time is long, the efficiency is low, and the requirements for the operation level of the personnel who operate the machine tool and the measuring device are high, and it cannot be realized quickly. In precision measurement, the operation, reading and writing of parameters, and writing of compensation values ​​are prone to errors, and regular maintenance of the machine tool cannot be realized. Summary of the Invention

[0003] The present invention provides a high-speed compensation system and compensation method for a machine tool based on the principle of laser interference, which overcomes the problems of needing additional auxiliary and power supply, complicated operation of the device, long measurement time, low efficiency, poor measurement accuracy, high requirements for operators, and inability to realize regular maintenance of the machine tool. [Problem to be solved by the invention]

[0004] In order to achieve the above objectives, the technical solutions of the present invention are as follows:

[0005] A high-speed compensation system for a machine tool based on a laser interference principle, comprising: a trigger collection module, a laser interference measurement module, a data analysis and compensation module, and a communication module, The trigger collection module is connected to the machine tool encoder, the numerical control system and the laser interferometry module, and the trigger collection module receives a trigger collection command sent from the numerical control system, converts the position value of the machine tool encoder into a pulse value and transmits it to the laser interferometry module; at the same time, the trigger collection module retrieves the parameter information and compensation point information of each axis of the machine tool in the numerical control system, and generates an operation code and a measurement preparation signal for the machine tool; The laser interference measurement module includes a laser head, an environment sensor, a temperature sensor, a light path redirecting device, a linear interference mirror, and a linear reflecting mirror; The laser head, the linear interference mirror and the optical path redirecting device are disposed at the stroke end of each axis of the numerically controlled machine tool, the laser head receives the measurement preparation signal and the pulse value to emit a laser, the laser is redirected by the optical path redirecting device to the X, Y and Z axes of the machine tool respectively through the linear interference mirror, the linear interference mirror cooperates with the linear reflecting mirror to obtain error data of the X, Y and Z axes of the machine tool, the environment sensor collects air temperature value, humidity value and atmospheric pressure value, and transmits the air temperature value, humidity value and atmospheric pressure value to the laser head to obtain environment data, the temperature sensor collects material temperature value of the X, Y and Z axes of the machine tool, and transmits the material temperature value to the laser head to obtain expansion compensation value, The data analysis and compensation module collects and analyzes the error data, the environment data and the expansion compensation value to obtain precision parameters used for precision analysis of the numerical control system and compensation parameters used for data compensation of the machine tool; The communication module is connected to the numerical control system and the data analysis and compensation module, and the communication module reads the compensation settings preset in the numerical control system, and transmits the compensation parameters and accuracy parameters generated by the data analysis and compensation module to the numerical control system.

[0006] In a specific embodiment, the parameter information of each axis of the machine tool includes stroke parameters of the X-, Y-, and Z-axes of the machine tool, and soft limit positions and overrides of the machine tool.

[0007] The compensation method utilizing the high-speed compensation system of the machine tool based on the laser interference principle is characterized in that it includes the following steps.

[0008] In step 1, the numerical control system reads the machine tool information and sets a trigger collection command, and the trigger collection module receives the trigger collection command and generates the machine tool operation code and the measurement preparation signal.

[0009] In step 2, the laser interference measurement module receives the measurement preparation signal to perform measurement, adjusts the linear interference mirror and the optical path redirecting device to measure the mechanical accuracy of the axis, obtains the error data of the X, Y, and Z axes of the machine tool, and simultaneously obtains the environmental data and expansion compensation value.

[0010] In step 3, the data analysis and compensation module collects and analyzes the error data, the environment data and the expansion compensation value to obtain a first accuracy parameter and a first compensation parameter.

[0011] In step 4, the numerical control system receives a first accuracy parameter and a first compensation parameter used in accuracy analysis and data compensation.

[0012] In a specific embodiment, the step 1 is specifically as follows:

[0013] In step 1.1, the numerical control system reads the machine tool information and sets the trigger collection command.

[0014] In step 1.2, the trigger collection module receives a trigger collection command, calls up the parameter information and preset compensation point information of each axis of the machine tool in the numerical control system, and obtains the machine tool operation code and measurement preparation signal based on the data interval and data starting point of the parameter information and compensation point information of each axis of the machine tool.

[0015] In step 1.3, the machine tool operation code is input into the numerical control system to wait for the operation, and the linear reflecting mirror is called at the same time.

[0016] In step 1.4, the machine tool operation code is executed and the laser interference detection module receives a measurement preparation signal.

[0017] In step 1.5, the trigger collection module collects and converts the position values ​​of the machine tool encoder into pulse values ​​and transmits them to the laser interferometry module.

[0018] In a specific embodiment, the step 2 is specifically as follows:

[0019] In step 2.1, the optical path deflector and linear reflecting mirror adjust the optical path and measure the mechanical accuracy of the axis.

[0020] In step 2.2, adjust the optical path redirecting device according to the type of measurement axis and the type and model of the machine tool, steer the laser to the measurement axis, and perform beam adjustment.

[0021] In step 2.3, the laser interference detection module detects the error data, the environmental data and the expansion compensation value based on the measurement preparation signal and the pulse value.

[0022] In step 2.4, the error data, environmental data and expansion compensation values ​​are stored and await the data analysis and compensation module to perform the analysis.

[0023] In a specific embodiment, in step 3, the data analysis and compensation module collects error data, environmental data and expansion compensation value, and analyzes and compares them with preset parameter standards to obtain a first accuracy parameter and a first compensation parameter.

[0024] In a specific embodiment, the process of obtaining the first compensation parameter is as follows.

[0025] In step 3.1, a compensation type data processing is performed on the error data, the environment data and the expansion compensation value to obtain a position deviation value.

[0026] In step 3.2, the position deviation value is subjected to sign normalization processing to obtain an error value.

[0027] In step 3.3, a compensation value for the error value is calculated based on the reference point, the compensation resolution and the calculation type as a first compensation parameter.

[0028] In a specific embodiment, the method further includes step 5, and step 5 is specifically as follows:

[0029] In step 5, the data analysis and compensation module sets initial evaluation parameters, compares the first accuracy parameter and the first compensation parameter with the initial evaluation parameters, and if the first accuracy parameter and the first compensation parameter are outside the preset parameter range, repeats steps 1 to 4 to obtain the second accuracy parameter and the second compensation parameter.

[0030] In a specific embodiment, the step 5 further includes: using a trigger collection module to modify the compensation point information, and further obtain a second precision parameter and a second compensation parameter. Effect of the Invention

[0031] The present invention uses a laser interference measuring device and a trigger collecting device to measure machine precision, and the measuring efficiency is higher, and the measuring precision is more accurate and faster. A data analysis and compensation module is added to load the compensation value into the numerical control system to realize the automated control. The laser interference measuring module and the trigger collecting module are fixed inside the machine tool, and do not need to be repeatedly installed and removed, which is convenient to use and avoids repeated installation.

[0032] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces drawings necessary for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative efforts. [Brief description of the drawings]

[0033] [Figure 1] FIG. 2 is a structural schematic diagram of the compensation system of the present invention; [Diagram 2] FIG. 2 is a schematic diagram of the logical structure of the compensation system of the present invention. [Diagram 3] FIG. 13 is a diagram showing the effect after the present invention is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the drawings in the embodiments of the present invention, but it should be obvious that the described embodiments are only some of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any creative efforts are within the scope of protection of the present invention.

[0035] This embodiment provides a high-speed compensation system for machine tools based on the principle of laser interference, which includes, as shown in FIG. 1, a trigger collection module, a laser interference measurement module, a data analysis and compensation module, and a communication module; The trigger collection module is connected to the machine tool encoder, the numerical control system and the laser interferometry module, and the trigger collection module receives a trigger collection command sent from the numerical control system, converts the position value of the machine tool encoder into a pulse value and transmits it to the laser interferometry module; at the same time, the trigger collection module retrieves the parameter information and compensation point information of each axis of the machine tool in the numerical control system, and generates an operation code and a measurement preparation signal for the machine tool; The laser interference measurement module includes a laser head, an environment sensor, a temperature sensor, a light path redirecting device, a linear interference mirror, and a linear reflecting mirror; The positions of the laser head, the linear interference mirror and the optical path redirecting device can be adjusted according to the type and application of the machine tool, and the laser head, the linear interference mirror and the optical path redirecting device can be arranged at the stroke end of each axis of the numerically controlled machine tool or at a fixed position of the motion axis; the laser head receives the measurement preparation signal and the pulse value and emits a laser, and the laser is respectively redirected to the X, Y and Z axes of the machine tool by the optical path redirecting device through the linear interference mirror; the linear interference mirror cooperates with the linear reflecting mirror to obtain the error data of the X, Y and Z axes of the machine tool; the environment sensor collects the air temperature value, humidity value and atmospheric pressure value, and transmits the air temperature value, humidity value and atmospheric pressure value to the laser head to obtain the environment data; the temperature sensor collects the material temperature value of the X, Y and Z axes of the machine tool, and transmits the material temperature value to the laser head to obtain the expansion compensation value; The data analysis and compensation module collects and analyzes the error data, the environment data and the expansion compensation value to obtain precision parameters used for precision analysis of the numerical control system and compensation parameters used for data compensation of the machine tool; The communication module is connected to the numerical control system and the data analysis and compensation module, and the communication module reads the compensation settings preset in the numerical control system, and transmits the compensation parameters and accuracy parameters generated by the data analysis and compensation module to the numerical control system.

[0036] In a specific embodiment, the parameter information of each axis of the machine tool includes stroke parameters of the X-, Y-, and Z-axes of the machine tool, and soft limit positions and overrides of the machine tool.

[0037] For the same purpose, as shown in FIG. 2, the present invention further provides a compensation method using a high-speed compensation system of a machine tool based on the laser interference principle, which is characterized in that it includes the following steps:

[0038] In step 1, the numerical control system reads the machine tool information and sets a trigger collection command, and the trigger collection module receives the trigger collection command and generates the machine tool operation code and the measurement preparation signal.

[0039] In step 2, the laser interference measurement module receives the measurement preparation signal to perform measurement, adjusts the linear interference mirror and the optical path redirecting device to measure the mechanical accuracy of the axis, obtains the error data of the X, Y, and Z axes of the machine tool, and simultaneously obtains the environmental data and expansion compensation value.

[0040] In step 3, the data analysis and compensation module collects and analyzes the error data, the environment data and the expansion compensation value to obtain a first accuracy parameter and a first compensation parameter.

[0041] In step 4, the numerical control system receives a first accuracy parameter and a first compensation parameter used in accuracy analysis and data compensation.

[0042] In a specific embodiment, the step 1 is specifically as follows:

[0043] In step 1.1, the numerical control system reads the machine tool information and sets the trigger collection command.

[0044] In step 1.2, the trigger collection module receives a trigger collection command, calls up the parameter information and preset compensation point information of each axis of the machine tool in the numerical control system, and obtains the machine tool operation code and measurement preparation signal based on the data interval and data starting point of the parameter information and compensation point information of each axis of the machine tool.

[0045] In step 1.3, the machine tool operation code is input into the numerical control system to wait for the operation, and the linear reflecting mirror is called at the same time.

[0046] In step 1.4, the machine tool operation code is executed and the laser interference detection module receives a measurement preparation signal.

[0047] In step 1.5, the trigger collection module collects and converts the position values ​​of the machine tool encoder into pulse values ​​and transmits them to the laser interferometry module.

[0048] In a specific embodiment, the step 2 is specifically as follows:

[0049] In step 2.1, the optical path deflector and linear reflecting mirror adjust the optical path and measure the mechanical accuracy of the axis.

[0050] In step 2.2, adjust the optical path turning device according to the type of measurement axis and the type and model of the machine tool, turn the laser to the measurement axis, and perform beam adjustment. For example, for a gantry structure and machining center, the laser head, the linear interference mirror and the optical path turning device may be placed at the stroke end of each axis, and for a single-motion axis or grinding machine structure, the assembly may be placed at a fixed position of the axis.

[0051] In step 2.3, the laser interference detection module detects the error data, the environmental data and the expansion compensation value based on the measurement preparation signal and the pulse value.

[0052] Here, the error data is the position deviation, and the specific calculation formula for the position deviation is x ij =P ji -P i and Where i is the measurement run number, j is the specific target point at the measurement run number, and the target position: P i (i=1~m), and the actual position is P ij (i=1~m, j=1~n), The average position deviation in one direction at a given position is

number

number

[0053] The data analysis and compensation module performs data analysis and report generation based on relevant standards, and performs analysis to determine whether compensation is necessary, for example, performs deviation position data analysis based on ISO, GB, JIS, ASME and VDI standards on the collected position deviation data, automatically saves the analyzed data parameters and images for the operator to refer to, and at the same time determines whether the system needs compensation based on the preset parameter standards (such as ISO positioning accuracy, repeat positioning accuracy, reverse direction clearance, etc.). Performs data compensation for data that exceeds the parameter standard and records the number of compensations, i.e., after each compensation, it is determined again whether the data exceeds the parameter standard. If not, there is no need to recompensate, while if not, it performs data compensation again. Note that if the compensation number reaches three times, i.e., none of the data after three compensations meets the standard, the system performs analysis based on the data, and presents possible problems for on-site personnel to refer to and investigate.

[0054] In a specific embodiment, in step 3, the data analysis and compensation module collects error data, environmental data and expansion compensation value, and analyzes and compares them with preset parameter standards to obtain a first accuracy parameter and a first compensation parameter.

[0055] The communication module reads the preset parameter standards (eg, compensation reference point, compensation interval, compensation start and end points, compensation method, compensation type, calculation type, etc.) in the numerical control system via the RJ45 communication port.

[0056] In a specific embodiment, the first compensation parameter z ij or z ij ↑ and z ij The process to obtain ↓ is as follows:

[0057] In step 3.1, based on the compensation type, we obtain the following: The numerical value of the position deviation with standard compensation is:

number

[0058] If the calculation type is absolute,

number

number

[0059] In a specific embodiment, the method further includes step 5, and step 5 is specifically as follows:

[0060] In step 5, the data analysis and compensation module sets an initial evaluation parameter, compares the first accuracy parameter and the first compensation parameter with the initial evaluation parameter, and if the preset parameter range is exceeded, repeat steps 1 to 4 to obtain a second accuracy parameter and a second compensation parameter. If the preset parameter range is exceeded, it indicates that the compensation parameter and accuracy parameter are not ideal, and the compensation parameter and accuracy parameter need to be obtained a second time, and superimposed with the first compensation parameter and accuracy parameter for use in verifying the numerical control system, and this process needs to be repeated until the parameter range is met.

[0061] In a specific embodiment, the step 5 further includes: modifying compensation point information using a trigger collection module, and further obtaining a second precision parameter and a second compensation parameter, specifically, modifying the compensation point information according to measurement point information, where the measurement point information includes the stroke information obtained by the trigger module from the machine tool and the compensation parameter set artificially.

[0062] As shown in Figure 3, the method is implemented in a machining center. The actual effect verification is carried out using a third-party device. The figure shows the comparison of the position error of the Z axis before and after compensation. The curve before compensation is the solid line, and the curve after compensation is the dashed line. The analysis was carried out according to the international standard ISO230-2 2006. The positioning accuracy before compensation is 57.7 μm, the repeatability is 18.3 μm, and the deviation of the positioning system is 56 μm. After measurement and compensation using this method, the positioning accuracy was 4.7μm, the repeatability was 3.1μm, and the deviation of the positioning system was 3.5μm. Therefore, the accuracy data of the machine tool after compensation was significantly improved.

[0063] The measurement accuracy of the present invention can reach ±0.5PPM, the collection speed can reach up to 4m / s, and the sampling frequency can reach up to 10KhZ. High speed, high frequency and accurate data collection can be realized.

[0064] Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention, and are not intended to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified or some or all of the technical features thereof can be equivalently replaced, and such modifications or replacements do not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-speed compensation system for a machine tool based on a laser interference principle, comprising: a trigger collection module, a laser interference measurement module, a data analysis and compensation module, and a communication module, The trigger collection module is connected to the machine tool encoder, the numerical control system and the laser interferometry module, and the trigger collection module receives a trigger collection command sent from the numerical control system, converts the position value of the machine tool encoder into a pulse value and transmits it to the laser interferometry module; at the same time, the trigger collection module retrieves the parameter information and compensation point information of each axis of the machine tool in the numerical control system, and generates an operation code and a measurement preparation signal for the machine tool; The laser interference measurement module includes a laser head, an environment sensor, a temperature sensor, a light path redirecting device, a linear interference mirror, and a linear reflecting mirror; the laser head, the linear interference mirror and the optical path redirecting device are disposed at the stroke end of each axis of the numerically controlled machine tool; the laser head receives the measurement preparation signal and the pulse value to emit a laser, the laser is redirected by the optical path redirecting device to the X, Y and Z axes of the machine tool respectively through the linear interference mirror; the linear interference mirror cooperates with the linear reflecting mirror to obtain error data of the X, Y and Z axes of the machine tool; the environment sensor collects air temperature values, humidity values ​​and atmospheric pressure values, and transmits the air temperature values, humidity values ​​and atmospheric pressure values ​​to the laser head to obtain environment data; the temperature sensor collects material temperature values ​​of the X, Y and Z axes of the machine tool, and transmits the material temperature values ​​to the laser head to obtain expansion compensation values; The data analysis and compensation module collects and analyzes the error data, the environment data and the expansion compensation value to obtain precision parameters used for precision analysis of the numerical control system and compensation parameters used for data compensation of the machine tool; The high-speed compensation system for a machine tool based on the laser interference principle, characterized in that the communication module is connected to a numerical control system and a data analysis and compensation module, and the communication module reads the compensation settings preset in the numerical control system, and transmits the compensation parameters and accuracy parameters generated by the data analysis and compensation module to the numerical control system.

2. The high-speed compensation system for a machine tool based on the laser interference principle as claimed in claim 1, characterized in that the parameter information of each axis of the machine tool includes stroke parameters of the X, Y, and Z axes of the machine tool, and soft limit positions and overrides of the machine tool.

3. Step 1: a numerical control system reads machine tool information and sets a trigger collection command, a trigger collection module receives the trigger collection command and generates a machine tool operation code and a measurement preparation signal; Step 2: the laser interference measurement module receives the measurement preparation signal to perform measurement, adjusts the linear interference mirror and the optical path redirecting device to measure the mechanical accuracy of the axis, obtains the error data of the X, Y, and Z axes of the machine tool, and simultaneously obtains the environmental data and the expansion compensation value; Step 3: a data analysis and compensation module collects and analyzes the error data, the environment data and the expansion compensation value to obtain a first accuracy parameter and a first compensation parameter; The compensation method for a high-speed compensation system of a machine tool based on the laser interference principle as claimed in claim 2, further comprising: a step 4 in which the numerical control system receives a first accuracy parameter and a first compensation parameter used for accuracy analysis and data compensation.

4. Specifically, step 1 includes: Step 1.1: The numerical control system reads the machine tool information and sets the trigger acquisition command; Step 1.2: the trigger collection module receives the trigger collection command, calls up the parameter information and the preset compensation point information of each axis of the machine tool in the numerical control system, and obtains the machine tool operation code and the measurement preparation signal according to the parameter information and the data interval and the data start point of the compensation point information of each axis of the machine tool; Step 1.3: inputting the machine tool operation code into the numerical control system and waiting for the operation, and simultaneously calling the linear reflecting mirror; Step 1.4: executing a machine tool operation code, and a laser interference detection module receiving a measurement preparation signal; 4. The compensation method for a high-speed compensation system of a machine tool based on the laser interference principle as claimed in claim 3, further comprising: step 1.5, in which the trigger collection module collects and converts the position value of the machine tool encoder into a pulse value, and transmits it to the laser interference measurement module.

5. Specifically, step 2 includes: Step 2.1, in which a light path deflector and a linear reflecting mirror adjust the light path and measure the mechanical accuracy of the axis; Step 2.2: adjusting the optical path redirecting device according to the type of the measurement axis and the type and model of the machine tool, redirecting the laser to the measurement axis, and adjusting the beam; Step 2.3: the laser interference detection module detects error data, environment data and expansion compensation value according to the measurement preparation signal and the pulse value; 5. The compensation method for a high-speed compensation system of a machine tool based on the laser interference principle as claimed in claim 4, further comprising: step 2.4 of storing the error data, the environmental data and the expansion compensation value, and waiting for the data analysis and compensation module to perform analysis.

6. The compensation method for a high-speed compensation system of a machine tool based on the principle of laser interference as claimed in claim 5, characterized in that in step 3, the data analysis and compensation module collects error data, environmental data and expansion compensation value, and analyzes and compares them with preset parameter standards to obtain first accuracy parameters and first compensation parameters.

7. The process of obtaining the first compensation parameter includes: Step 3.1, performing compensation type data processing on the error data, the environmental data and the expansion compensation value to obtain a position deviation numerical value; Step 3.2: performing a sign normalization process on the position deviation value to obtain an error value; 7. The compensation method for a high-speed compensation system of a machine tool based on the laser interference principle as claimed in claim 6, further comprising: a step 3.3 of calculating a compensation value of the error value as a first compensation parameter based on the reference point, the compensation resolution and the calculation type.

8. The compensation method for a high-speed compensation system of a machine tool based on the principle of laser interference as claimed in claim 3, characterized in that the data analysis and compensation module further includes step 5 of setting initial evaluation parameters, comparing a first accuracy parameter and a first compensation parameter with the initial evaluation parameters, and repeating steps 1 to 4 to obtain a second accuracy parameter and a second compensation parameter if the first accuracy parameter and the first compensation parameter exceed the preset parameter range.

9. The compensation method for a high-speed compensation system of a machine tool based on the principle of laser interference as claimed in claim 8, wherein step 5 further includes: using a trigger collection module to modify compensation point information, and further obtaining a second accuracy parameter and a second compensation parameter.

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