A method for detecting and compensating the independent dual-drive synchronization accuracy of CNC machine tools

Abstract

The present invention relates to the technical field of precision debugging of numerically controlled machine tools, and discloses a method for detecting and compensating the independent dual-drive synchronization precision of a numerically controlled machine tool. The method sets the number of detection points according to the travel range of the dual-drive shaft, thereby calculating the detection step and setting a plurality of detection points; then compiles an NC program and starts it, sequentially controls the dual-drive shaft to move to the set detection points in the forward and reverse directions, and then reads the corresponding values ​​of the level gauge on the dual-drive shaft beam at the detection points; then, according to the actual machining precision requirements, the obtained level gauge values ​​are subjected to data processing, and the dual-drive shaft synchronization precision errors corresponding to the detection points within the travel range of the dual-drive shaft are obtained; finally, the dual-drive shaft synchronization precision errors are used, and any one of the dual-drive shafts is used as the compensation reference to compensate for the other shaft. The present invention can complete the detection of the dual-drive shaft synchronization precision errors of machine tools using conventional monitoring equipment, saving the purchase or rental costs of expensive detection equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of precision debugging of numerically controlled machine tools, and more particularly to a method for detecting and compensating the independent dual-drive synchronous precision of numerically controlled machine tools. Background Art

[0002] If there is a synchronization accuracy deviation during the synchronous movement of the dual-drive axes, it will cause the current and load of the drive motor to be too large, affecting the service life of the motor and drive module components, and also causing abnormal wear on the mechanical drive components. Especially for CNC machine tools with dual-drive vertical axes, the impact of synchronization accuracy deviation on mechanical and electrical systems is particularly severe.

[0003] For example, the invention patents disclosed as CN114473631A and CN113188479A respectively disclose a method for gantry synchronization adjustment of a dual-drive system and a method for detecting parallelism of a large-span guide rail. The above two patents respectively set up laser interferometers on the dual-drive shafts to obtain the position error of the dual-drive shafts, and then compensate the obtained error into the pitch error system. The patented method requires two sets of laser interferometers for detection. The equipment is expensive, and the two sets of laser interferometers need to be used in conjunction. The technology is difficult, the operation is cumbersome, and the detection takes a long time.

[0004] For example, patent publication number CN103551627A discloses a method for deep-hole machining on a pentahedron gantry CNC machine tool. Two electronic levels are placed on the worktable along the X and Y axes to detect the levelness of the worktable during movement. However, this patented method only detects the levelness of the worktable and adjusts it to meet the requirements using anchor screws, a common testing and adjustment method in the industry. Summary of the Invention

[0005] This invention proposes a method for detecting and compensating the synchronization accuracy of independent dual-drive axes on CNC machine tools. By using a high-precision level and mounting bracket, this method acquires synchronization accuracy error data at multiple detection points within the travel range of the dual-drive axes. This data is then used to compensate for the other axis, with one axis serving as the compensation reference. This invention addresses the problem of synchronization accuracy errors occurring during the movement of CNC machine tools with dual-drive vertical axes.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0007] The present invention discloses a method for detecting and compensating the independent dual-drive synchronization accuracy of a numerically controlled machine tool, the method comprising the following steps:

[0008] Step S1. First, install an L-shaped or other shaped bracket on the dual-drive shaft beam, and then install and place the spirit level on the bracket. During the detection process, the spirit level moves together with the dual-drive shaft beam; then, set the number of detection points within the travel range according to the travel range of the dual-drive shaft, thereby calculating the detection step distance and setting multiple detection points, each detection point has corresponding coordinates.

[0009] In the present invention, the travel range of the dual drive shaft is n=|n max |+|n min |, where n max The maximum limit of the dual-drive axis coordinate, n min It is the minimum limit of the coordinate of the dual-drive axis. Usually, in order to ensure the normal operation of the machine tool, n max Generally, 10mm is subtracted from the maximum limit of the dual-drive axis coordinates. Similarly, n min Generally, 10mm is added to the minimum limit of the dual-drive axis coordinates.

[0010] Furthermore, the calculation expression of the detection step U is as follows:

[0011]

[0012] Where m is the number of set detection points.

[0013] Step S2. Compile and start the NC program, control the dual-drive axes to move to the set detection points in sequence, and then read the level value corresponding to the detection point.

[0014] In the present invention, during the precision detection process, the dual-drive shaft will usually move in the forward direction first to the set detection points in sequence. At this time, the values ​​of the level instrument corresponding to each detection point during the forward movement will be obtained; then the dual-drive shaft moves in the reverse direction, and the values ​​of the level instrument are read when it moves to the corresponding detection point. Finally, two sets of level instrument values, namely the values ​​of the level instrument corresponding to each detection point during the forward movement and the values ​​of the level instrument corresponding to each detection point during the reverse movement, will be obtained.

[0015] In the present invention, when the machine tool NC program is started, the data acquisition function or data monitoring function (TRACE function) of the CNC machine tool is usually started synchronously to collect the current value of the dual-drive axis during the movement.

[0016] In the present invention, the NC program compiled in step S2 takes the dual-drive axis Y axis as an example, and the program is as follows:

[0017] G500; activate the machine coordinate system

[0018] G01 F5000 Y=n min ; 5000mm / minMove the Y axis to the set detection point T1 at a speed of

[0019] M0: The program pauses, and the position of the level is adjusted so that the pointer points to zero, and the value is recorded as V1.

[0020] CYCLEA G91 Y=U G4 F5; continue executing the program and move the Y axis in incremental feed mode with the incremental feed amount being U. After reaching the target position T2, pause for 5 seconds and record the level value V2.

[0021] REPEAT CYCLEA P=m-2;Repeat the above CYCLEA program segment, the number of cycles is P, and the final movement Y axis position is n max , record the arrival at the target position (T3, T4----T m ) when the level value (V3, V4...V m )

[0022] G91 Y=5; Y axis continues to move forward 5mm

[0023] G91 Y=-5G4 F5; Y axis moves back 5mm and pauses for 5S, recording the level value V m+1

[0024] CYCLEB G91 Y=-U ​​G4 F5; Set the Y axis to move in incremental feed mode, with the incremental feed amount being -U. After reaching the target position, pause for 5 seconds and record the level value V. m+2

[0025] REPEAT CYCLEB P=m-2;Repeat the above CYCLEB program segment for P times, and finally move the Y axis to the position of n mmn , record the level value (V m+3 、V m+4 ...V m+m )

[0026] M30; program ends

[0027] Step S3. According to the actual processing accuracy requirements, the two sets of level values ​​obtained in step S2 are processed, and the dual-drive shaft synchronization accuracy error corresponding to each detection point within the dual-drive shaft stroke is calculated.

[0028] Step S4: Using the calculated dual-drive axis synchronization accuracy error, taking any one of the dual-drive axes as the compensation reference, compensate the other axis.

[0029] When using machine tools to process products, if the product processing accuracy requirements are low, or the number of initially set detection points is large, the average value of the two sets of level values ​​can be proportionally amplified and used as the synchronization accuracy error to compensate for the accuracy of the dual-drive axis. The specific process is as follows:

[0030] When the dual-drive shaft moves forward and backward to the same detection point, the two obtained level values ​​are averaged and the calculation expression is as follows:

[0031] H m =(V m +V m+1 ) / 2;

[0032] Among them, H m The dual-drive axis moves forward and reverse to the same detection point T m The average value of the corresponding level value; V m The dual drive axis moves forward to the detection point T m Level value when V m+1 The dual drive shaft moves in the opposite direction to the detection point T m Level value;

[0033] Then the average value H of the level value of all the detection points is obtained m According to the size of the level and the size of the dual-drive axis beam, the synchronous accuracy error corresponding to each detection point is calculated. The calculation expression is as follows:

[0034] Q / W=H m / S;

[0035] S=WH m / Q;

[0036] Among them, Q is the length of the level; S is the synchronization accuracy error corresponding to the detection point; W is the length of the dual-drive axis beam;

[0037] Furthermore, the synchronization accuracy error obtained by the above calculation is used to perform precision compensation on the dual-drive shaft. The specific process is as follows:

[0038] 1) If the driving shaft is used as the compensation basis to compensate the driven shaft, the compensation process is as follows:

[0039] If the synchronization accuracy error S>0, it means that the active axis is higher and the driven axis is lower when the dual-drive axis moves, then the compensation value of the driven axis is +S;

[0040] If the synchronization accuracy error S<0, it means that the active axis is low and the driven axis is high when the dual-drive axis moves, then the compensation value of the driven axis is -|S|, where |S| represents the absolute value of the synchronization error value S;

[0041] 2) If the driven axis is used as the compensation basis to compensate the driving axis, the compensation process is as follows:

[0042] If the synchronization accuracy error S>0, it means that the active axis is higher and the driven axis is lower when the dual-drive axis moves, then the compensation value of the active axis is -S;

[0043] If the synchronization accuracy error S<0, it means that the active axis is low and the driven axis is high when the dual-drive axis moves, then the compensation value of the active axis is +|S|, and |S| represents the absolute value of the synchronization error value S.

[0044] Furthermore, the compensation value is input into the compensation system. The compensation list template program is as follows:

[0045] ﹩AN_CEC[D,1]=S1;

[0046] =AN_CEC[D,2]=S2;

[0047] ...;

[0048] ﹩AN_CEC[D, m]=S m ;

[0049] ﹩AN_CEC_INPUT[D]=E;

[0050] ﹩AN_CEC_OUTPUT[D]=F;

[0051] ﹩AN_CEC_STEP[D]=(|n max |+|n min |) / m

[0052] ﹩AN_CEC_MIN[D]=n min ;

[0053] ﹩AN_CEC_MAX[D]=n max ;

[0054] Where, E represents the reference coordinate axis (input axis), F represents the coordinate axis to be compensated (output axis), D represents the axis number corresponding to the axis to be compensated, and m represents the number of detection points divided by the motion range on the reference coordinate axis (S1, S2...S m ) represents the m compensation values ​​corresponding to the detection point. It is necessary to determine which axis is the compensation reference axis according to the actual compensation mode of the machine tool and then modify the compensation value. ﹩AN_CEC_ is a special symbol for the compensation module of the CNC system, n min 、n max Respectively represent the minimum and maximum values ​​of the running stroke.

[0055] When the data obtained after proportional amplification of the average value is used as the synchronization accuracy error to perform precision compensation on the dual-drive shaft, the compensation efficiency can be improved and the effect of rapid compensation and adjustment of the dual-drive shaft can be achieved.

[0056] If a product processed by a CNC machine tool requires high machining accuracy, or the number of detection points initially set is small (considering that the compensation points are insufficient), using the average value for proportional amplification and then performing precision compensation will result in unsatisfactory machine tool precision compensation and poor compensation effect. Therefore, the present invention also provides another method for calculating the synchronization accuracy error to improve the compensation accuracy of the machine tool. The specific process is as follows:

[0057] Based on the synchronization accuracy error corresponding to each detection point obtained after the above-mentioned average value of the level is amplified by equal proportion, the coordinates of each detection point and its corresponding synchronization accuracy error are subjected to binomial fitting. Finally, the fitting relationship between the synchronization accuracy error and the detection point coordinates is obtained, and the following fitting relationship is obtained:

[0058] S=W0+W1T+W2T 2 ;

[0059] Where T is the point to be compensated; S is the synchronization accuracy error; W0 is the polynomial constant term, W1 is the polynomial linear term, and W2 is the polynomial quadratic term.

[0060] In the above fitting relationship, the fitting coefficient is calculated using the coordinates of the detection point and its corresponding synchronization accuracy error. The calculation formula is as follows:

[0061]

[0062] Among them, T i 、S i are the coordinates of the i-th detection point and its corresponding synchronization accuracy error;

[0063] Based on the above fitting relationship, according to the actual processing accuracy requirements, more points to be compensated are set, or according to the compensation points in the compensation list when the machine tool leaves the factory, the coordinate values ​​of more compensation points are brought into the above fitting relationship, and the corresponding synchronous accuracy error value is calculated. Then, the synchronous accuracy error value is used for accuracy compensation. The specific accuracy compensation method can refer to the above-mentioned process of compensation using the average value, which will not be explained in detail here.

[0064] Furthermore, in order to verify the effect of the above-mentioned precision compensation and ensure the machining accuracy of the machine tool, the present invention also includes a precision compensation verification step, and the specific process is as follows:

[0065] First, the current value of the dual-drive axis during the motion process collected by the NC program in step S2 is filtered, that is, the current value at the moment of starting and stopping the drive axis is filtered out, and the maximum effective current value of the dual-drive axis I is obtained. max1 ;

[0066] Then, execute the NC program in step S2 again and start the machine tool data acquisition function or data monitoring function at the same time to obtain the new effective maximum current I max2 , and execute step S3 again to obtain a new synchronization accuracy error, and then select the value with the largest absolute value in the new synchronization accuracy error as the maximum error value S max ; Finally, use the new maximum synchronization accuracy error S max And the effective maximum current I max2 , verify the accuracy compensation effect.

[0067] Furthermore, the verification process of the accuracy compensation effect is as follows:

[0068] Step 1. If S max The value of is less than or equal to the accuracy allowed value, and I max2 The value is less than or equal to I max1 When the precision compensation effect is good, it meets the processing requirements of machine tools;

[0069] Step 2. If S max The value is less than or equal to the accuracy allowed value, I max2 The value is greater than I max1 When the precision compensation effect is good, there is stress on the beam connecting the dual-drive shaft, which will have an unfriendly effect on the mechanical drive components. The mechanical components need to be adjusted to release the stress.

[0070] Step 3. If S max The value is greater than the accuracy allowed, I max2 The value is greater than I max1 When the precision compensation effect is not good, the compensation parameters do not match the mechanical state, and the mechanical drive components need to be adjusted accordingly;

[0071] Step 4. If S max The value is greater than the accuracy allowed, I max2 The value is less than I max1 When the accuracy compensation effect is not ideal, it is necessary to perform the above detection and compensation steps again until S max and I max2 The value of meets the requirements.

[0072] In the present invention, the allowable accuracy value is set by the technicians themselves, and can be set according to the machine tool structure, or obtained by querying relevant accuracy calibration.

[0073] Beneficial effects of the present invention:

[0074] 1. The present invention can complete the detection of the synchronization accuracy error of the dual-drive axes of a machine tool using conventional monitoring instruments, saving a large amount of expensive purchase or rental costs of detection equipment, and having considerable economic benefits.

[0075] 2. The method of the present invention has simple and convenient operation steps, and can be completed by ordinary technicians through simple training, which has the economic significance of large-scale technology promotion.

[0076] 3. The detection and compensation time of the method of the present invention is short, which can avoid a lot of equipment downtime. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The foregoing and following detailed description of the present invention will become more apparent when read in conjunction with the following drawings, in which:

[0078] Figure 1 This is a schematic diagram of the use of the level meter of the present invention in conjunction with the L-shaped bracket;

[0079] Figure 2 This is a schematic diagram of synchronization accuracy detection of the present invention;

[0080] Figure 3 Schematic diagram of the dual-drive axis posture when the synchronization error accuracy of the present invention is greater than zero;

[0081] Figure 4 This is a schematic diagram of the dual-drive axis posture when the synchronization error accuracy of the present invention is less than zero.

[0082] In the picture:

[0083] 1. Level; 2. L-shaped bracket; 3. Mounting hole; 4. Driven shaft; 5. Dual-drive shaft crossbeam; 6. Driving shaft. DETAILED DESCRIPTION

[0084] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions for achieving the purposes of the present invention will be further illustrated below through specific embodiments. It should be noted that the technical solutions claimed for protection by the present invention include but are not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0085] If there is a synchronization accuracy deviation during the synchronous movement of the dual-drive axes, it will cause the current and load of the drive motor to be too large, affecting the service life of the motor and drive module components, and also causing abnormal wear on the mechanical drive components. Especially for CNC machine tools with dual-drive vertical axes, the impact of synchronization accuracy deviation on mechanical and electrical systems is particularly severe.

[0086] Currently, the synchronization accuracy of dual-drive axes is typically tested by installing laser interferometers on each axis to obtain their positional errors, which are then applied to the pitch error system. Two sets of laser interferometers are used throughout the compensation process. These expensive laser interferometers lead to high testing costs, and the coordinated use of these two sets of interferometers during the testing process is technically challenging, cumbersome, and time-consuming.

[0087] Based on this, an embodiment of the present invention proposes a method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool. This method uses a conventional level to complete the detection and compensation of the dual-drive axis synchronization accuracy errors of the machine tool, saving a large amount of expensive detection equipment purchase or rental costs, and has considerable economic benefits.

[0088] The present invention will be explained and illustrated in more detail below in conjunction with specific implementation methods.

[0089] Example 1

[0090] This embodiment discloses a method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool. The equipment used in the method includes a high-precision level and an L-shaped bracket. The screw holes of the L-shaped bracket are consistent with the screw holes on the dual-drive axis crossbeam. Before starting the machine tool for accuracy detection, the L-shaped bracket is installed on the dual-drive axis crossbeam, and then the level is placed on the L-shaped bracket. The level is placed in a direction parallel to the dual-drive axis crossbeam, such as Figure 1 and Figure 2 As shown, after the level is installed in place, the compiled NC program is started to start accuracy detection and compensation. The specific solution adopted is as follows:

[0091] Take the Y axis of a certain type of CNC machine tool as an example. The negative soft limit of the machine tool is set to -1285mm, and the positive soft limit is 1215mm. The number of detection points within the travel range is set to m = 9, then n max =1215-10=1205mm, n min =-1285+10=-1275mm, moving range n=|n max |+|n min |=2480mm; further calculate the detection step distance The corresponding NC program is listed below. Start the NC program and execute the corresponding detection steps:

[0092] G500; activate the machine coordinate system;

[0093] G01 F5000 Y=n min =-1275; 5000mm / minMove the Y axis to the set detection point T1 at a speed of T1 = -1275;

[0094] M0: The program pauses, adjusts the level position so that the pointer points to zero, and records the level value V1;

[0095] CYCLEAG91 Y=U=310G4 F5; Continue executing the program to move the Y axis in incremental feed mode with an incremental feed of 310. After reaching the next detection point T2=-965, pause for 5 seconds and record the level value V2.

[0096] REPEAT CYCLEAP=m-2=7; loop the above CYCLEA program segment, the number of cycles is 7, and the final movement of the Y axis position is n max =1205, record the level value (V3, V4...V9) when reaching the target position (T3, T4...T9)

[0097] G91 Y=5; Y axis continues to move forward 5mm

[0098] G91 Y=-5G4 F5; Y axis moves back 5mm and pauses for 5S, recording the level value V 10

[0099] CYCLEB G91 Y=-U ​​G4 F5; Set the Y axis to move in incremental feed mode, with the incremental feed amount being -U. After reaching the target position, pause for 5 seconds and record the level value V. 11

[0100] REPEAT CYCLEB P=m-2=7;Repeat the above CYCLEB program segment, the number of cycles is 7, and the final movement Y axis position is n min , record the level value (V 12 、V 13┈ V 18 )

[0101] M30; program ends.

[0102] Furthermore, the corresponding relationship between the coordinates of the detection points and the level readings is shown in Table 1 below:

[0103] Table 1 Relationship between detection point coordinates and level readings

[0104]

[0105] The value V in the above table is processed. Specifically, the value V when the dual-drive shaft moves forward and backward to the same coordinate position is averaged to obtain a new value H1=(V1+V 18 ) / 2, H2=(V2+V 17) / 2......H9=(V9+V 10 ) / 2,H m The corresponding relationship with the detection point coordinates is shown in Table 2 below:

[0106] Table 2 Relationship between the average value of the level and the coordinates of the detection points

[0107] T(1～9) -1275 -965 -655 -345 -35 275 585 895 1205 H(1～9) 0 0.001 0.003 0.005 0.08 0.011 0.015 0.019 0.022

[0108] Furthermore, the new level value H m According to the size of the level and the size of the dual-drive shaft beam, the true synchronization accuracy error S of the dual-drive shaft is calculated. The specific calculation process is as follows:

[0109] Assuming the level length Q = 210mm and the dual-drive shaft beam length W = 2300mm, we have:

[0110] Q / W=H / S;

[0111] S = WH / Q;

[0112] The corresponding relationship between the calculated dual-drive axis real synchronization accuracy error S and the detection point coordinates is shown in Table 3 below:

[0113] Table 3 Relationship between dual-drive axis synchronization accuracy error and detection point coordinates

[0114] T(1～9) -1275 -965 -655 -345 -35 275 585 895 1205 S(1～9) 0 0.011 0.033 0.055 0.088 0.121 0.165 0.209 0.242

[0115] Furthermore, assuming that the left axis when facing the dual-drive axis is the driven axis and the right axis is the active axis, the active axis is used as the compensation reference to compensate the driven axis, and the driven axis number is 7; at this time, the synchronization accuracy error S>0, which means that when the dual-drive axis moves, the active axis is higher and the driven axis is lower, then the compensation value of the driven axis is +S, such as Figure 3 shown.

[0116] Furthermore, the compensation value is input into the compensation system. The compensation list template program is as follows:

[0117] ﹩AN_CEC[7,1]=0;

[0118] ﹩AN_CEC[7,2]=0.011;

[0119] ...;

[0120] ﹩AN_CEC[7,9]=0.242;

[0121] ﹩AN_CEC_INPUT[7]=Y;

[0122] ﹩AN_CEC_OUTPUT[7]=Y;

[0123] ﹩AN_CEC_STEP[7]=310;

[0124] ﹩AN_CEC_MIN[7]=-1275;

[0125] ﹩AN_CEC_MAX[7]=1205.

[0126] Example 2

[0127] This embodiment discloses a method for detecting and compensating the synchronization accuracy of independent dual-drive axes of a CNC machine tool. Based on the above embodiment 1, this embodiment adopts a different method to calculate the synchronization accuracy error of the dual-drive axes. The details are as follows:

[0128] The coordinates (T1, T2...T9) in the above embodiment 1 and the corresponding synchronization accuracy errors (S1, S2...S9) are fitted with a polynomial. The polynomial fitting expression is as follows:

[0129] S=W0+W1T+W2T 2 ;

[0130] In the above expression, the fitting coefficient is calculated using the coordinates of the detection points and their corresponding synchronization accuracy errors. The calculation formula is as follows:

[0131]

[0132] m is the number of detection points, T i 、S i are the coordinates of the detected i-th detection point and its corresponding synchronization accuracy error, as shown in Example 1. Substituting the coordinates (T1, T2...T9) and the corresponding real synchronization accuracy errors (S1, S2...S9) in Example 1 into the calculation formula, we can get W0=-1158, W1=1.438×10 -4 , W2=-2.038×10 -4 According to the actual processing requirements, add points to be supplemented, or according to the compensation points stored in the machine tool compensation list, bring the coordinates of more points to be compensated into the above fitting relationship, calculate the synchronization accuracy error value under the coordinates of the points to be compensated, and then call the same dual-drive axis compensation process for compensation.

[0133] Example 3

[0134] This embodiment discloses a method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool. Based on the first or second embodiment, the data acquisition function or the data monitoring function of the machine tool is started while the NC program is started, the current value of the dual-drive axis is collected, and the obtained current value is filtered, that is, the current value at the moment of starting and stopping the drive axis is filtered out to obtain the effective maximum value I of the dual-drive axis current.max1 =10.57A; after the compensation is completed, the NC program in the above embodiment is executed again and the data acquisition function or data monitoring function is turned on to obtain a new effective maximum current value I max2 =4.37A, and executing the accuracy detection steps in the above embodiment, a new level value table as shown in Table 4 below is obtained.

[0135] Table 4 Relationship between new detection point coordinates and level readings

[0136]

[0137] The positive and negative movement values ​​V corresponding to the same detection point in the above table are averaged to obtain the new level value average, and then the largest absolute value is selected from the above level value averages for the same proportion amplification. The compensated S max =WH / Q=0.016mm, and finally according to S max and I max2 The compensation effect can be judged by the numerical value of .

[0138] In this embodiment, S max The value is less than the accuracy allowable system 0.05mm, and I max2 The value is less than I max1 , it can be considered that the precision compensation effect is good and meets the machining requirements of machine tools.

[0139] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool, characterized in that: The following steps are involved: Step S1. Install the spirit level on the dual-drive shaft beam, set the number of detection points within the travel range according to the dual-drive shaft travel range, calculate the detection step distance and set multiple detection points; Step S2. Compile and start the NC program, control the dual-drive axes to move to the set detection points in sequence, and then read the level value corresponding to the detection point; When starting the NC program of the machine tool, the data acquisition function or data monitoring function of the CNC machine tool is turned on to collect the current value of the dual-drive axis and filter the obtained current value to the effective maximum value of the dual-drive axis current. I max1 ; Step S3. According to the actual machining accuracy requirements, the obtained level value is processed and the dual-drive shaft synchronization accuracy error corresponding to each detection point within the dual-drive shaft travel is calculated; Step S4. Using the dual-drive axis synchronization accuracy error, taking any one of the dual-drive axes as the compensation reference, compensate the other axis; Step S5. Execute the NC program in step S2 again and start the machine tool data acquisition function or data monitoring function at the same time to obtain a new effective maximum current value. I max2 , and execute step S3 again to obtain a new synchronization accuracy error; the maximum absolute value of the new synchronization accuracy error is selected as the maximum error value S max , use the new maximum synchronization accuracy error S max And the effective maximum current I max2 , verify the accuracy compensation effect.

2. A method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool according to claim 1, characterized in that: In step S2, the travel range of the dual drive shaft is n =| n max |+| n min |, detection step ;in, n is the travel range of the dual drive shaft; n max It is the maximum limit of the coordinates of the dual-drive axis; n min It is the minimum limit of the coordinate of the dual-drive axis; m is the number of detection points; U To detect the step length.

3. The method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool according to claim 1, characterized in that: In step S3, the obtained level value is processed according to the actual processing accuracy requirements, and the dual-drive shaft synchronization accuracy error corresponding to each detection point within the dual-drive shaft travel is calculated, including: When the dual-drive shaft moves forward and backward to the same detection point, the two obtained level values ​​are averaged and the calculation expression is as follows: H m =（ V m + V m+1 ） / 2； in, H m For the dual drive axis to move forward and reverse to the same detection point T m The average value of the corresponding level values; V m The dual drive axis moves forward to the detection point T m Level value; V m+1 The dual drive shaft moves in the opposite direction to the detection point T m Level value; The average value of the level instrument at all detection points is magnified in proportion to the size of the level instrument and the size of the dual-drive axis beam, and the synchronization accuracy error corresponding to each detection point is calculated. The calculation expression is as follows: Q / W = H m / S ； S = WH m / Q ； in, Q is the length of the level; S To detect the synchronization accuracy error corresponding to the point; W is the length of the dual-drive axle crossbeam.

4. The method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool according to claim 1, characterized in that: In step S3, the obtained level value is processed according to the actual processing accuracy requirements, and the dual-drive shaft synchronization accuracy error corresponding to each detection point within the dual-drive shaft travel is calculated, including: When the dual-drive shaft moves forward and backward to the same detection point, the two obtained level values ​​are averaged and the calculation expression is as follows: H m =（ V m + V m+1 ） / 2； in, H m For the dual drive axis to move forward and reverse to the same detection point T m The average value of the corresponding level values; V m The dual drive axis moves forward to the detection point T m Level value; V m+1 The dual drive shaft moves in the opposite direction to the detection point T m Level value; The average value of the level instrument at all detection points is magnified in proportion to the size of the level instrument and the size of the dual-drive axis beam, and the synchronization accuracy error corresponding to each detection point is calculated. The calculation expression is as follows: Q / W = H m / S ； S = WH m / Q ； in, Q is the length of the level; S To detect the synchronization accuracy error corresponding to the point; W is the length of the dual-drive axle crossbeam; Furthermore, the obtained synchronization accuracy error at the detection point and the position coordinates of the detection point are subjected to polynomial fitting to obtain the following fitted synchronization accuracy error calculation expression. Finally, the coordinates of the point to be compensated are substituted into the fitted synchronization accuracy error calculation expression to obtain the synchronization accuracy error corresponding to the point: ； in, T The point to be compensated; S is the synchronization accuracy error.

5. The method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool according to claim 1, characterized in that: In step S4, any one of the dual-drive axes is used as a compensation reference to compensate the other axis, including: 1) Take the driving shaft as the compensation reference to compensate the driven shaft: If the synchronization accuracy error S When >0, it means that the active axis is high and the driven axis is low when the dual-drive axis moves, then the compensation value of the driven axis is + S ; If the synchronization accuracy error S When <0, it means that the active axis is low and the driven axis is high when the dual-drive axis moves, then the compensation value of the driven axis is , Indicates the absolute value of the synchronization accuracy error; 2) Compensate the active shaft using the driven shaft as the compensation reference: If the synchronization accuracy error S When >0, it means that the active axis is high and the driven axis is low when the dual-drive axis moves, then the compensation value of the active axis is - S ; If the synchronization accuracy error S When <0, it means that the active axis is low and the driven axis is high when the dual-drive axis moves. The compensation value of the active axis is , Indicates the absolute value of the synchronization error.

6. The method for detecting and compensating the independent dual-drive synchronization accuracy of a CNC machine tool according to claim 1, characterized in that: The verification process of the accuracy compensation effect is as follows: Step 1. If S max The value of is less than or equal to the precision allowed value, and I max2 The value is less than or equal to I max1 When the precision compensation effect is good, it meets the processing requirements of machine tools; Step 2. If S max The value of is less than or equal to the precision allowed value, I max2 The value is greater than I max1 When , the precision compensation effect is good, but there is stress on the beam connecting the dual-drive shaft; Step 3. If S max The value of is greater than the precision allowed. I max2 The value is greater than I max1 When , the accuracy compensation effect is not good; Step 4. If S max The value of is greater than the precision allowed. I max2 The value is less than I max1 When the accuracy compensation effect does not reach the ideal state, it is necessary to perform the above-mentioned detection steps S2-S3 and compensation steps S4 again.

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