CN-121979102-A - Rolling element precision turning precision error compensation control system

CN121979102ACN 121979102 ACN121979102 ACN 121979102ACN-121979102-A

Abstract

The application relates to the technical field of precision machining control and discloses a precision turning error compensation control system for rolling bodies, which comprises a multi-source heterogeneous sensing module, a dynamic stiffness modeling module, an angle domain phase coupling module, an error prediction module and a compensation execution module, wherein the multi-source heterogeneous sensing module is used for collecting various signals, the dynamic stiffness modeling module is used for constructing a circumferential dynamic stiffness distribution model distributed along the circumferential direction of a workpiece, the angle domain phase coupling module is used for outputting a comprehensive feature vector containing stiffness modulation deformation and an equivalent main shaft geometric error, the error prediction module is used for predicting and outputting a roundness error prediction value of the next angle step length, and the compensation execution module is used for dynamically superposing the position compensation instruction to an original interpolation instruction of a numerical control system and driving a servo shaft to execute displacement compensation. According to the method, by constructing the circumferential dynamic stiffness model and applying the angle domain phase coupling, the accurate calculation of the time-space alignment of the sensor data and the elastic deformation of the cutting point is realized, and the real-time prediction precision and compensation effect of the turning roundness error of the rolling body are improved.

Inventors

FAN JIASHUANG
QIU JUN
CHEN XIANG
LV JINBAO
CHEN YULIANG

Assignees

贝尔数据科技（大连）有限公司

Dates

Publication Date: 20260505
Application Date: 20260128

Claims (10)

1. The utility model provides a precision turning precision error compensation control system of rolling element which characterized in that includes: the multi-source heterogeneous sensing module is used for collecting a radial runout signal, a three-way cutting force signal, a workpiece clamping contour signal and a main shaft rotary encoder signal of the main shaft in real time; The dynamic stiffness modeling module is used for constructing a circumferential dynamic stiffness distribution model distributed along the circumferential direction of the workpiece according to the workpiece clamping profile signal; The angle domain phase coupling module is used for mapping the spindle radial runout signal and the three-way cutting force signal to a workpiece rotation angle domain by utilizing the spindle rotation encoder signal, calculating the ratio of the angle domain cutting force to the corresponding phase stiffness value to obtain a stiffness modulation deformation, and outputting a comprehensive feature vector containing the stiffness modulation deformation and an equivalent spindle geometric error; The error prediction module is used for inputting the comprehensive feature vector into a pre-trained long-short-time memory network model, and predicting and outputting a roundness error prediction value of the next angle step; and the compensation execution module is used for generating a position compensation instruction according to the roundness error predicted value, dynamically superposing the position compensation instruction to an original interpolation instruction of the numerical control system, and driving a servo shaft to execute displacement compensation.
2. The rolling element precision turning precision error compensation control system of claim 1, wherein the multi-source heterogeneous sensing module comprises: the orthogonal displacement sensing unit comprises two sets of capacitive displacement sensors which are orthogonally arranged on the end face of the spindle and are used for collecting radial runout signals of the spindle in the X direction and the Y direction; the cutting force sensing unit comprises a strain gauge type force measuring instrument integrated on a lathe fixture base and is used for acquiring the three-way cutting force signals in the X-axis, Y-axis and Z-axis directions; And the clamping profile scanning unit comprises a laser displacement sensor which is arranged perpendicular to the clamping surface of the workpiece and is used for scanning the surface of the workpiece in a low-speed rotation state of the spindle so as to acquire the clamping profile signal of the workpiece.
3. The system according to claim 2, wherein the orthogonal displacement sensor unit uses a cutting point position of the turning tool contacting the workpiece as a phase zero reference, the two sets of capacitance displacement sensors have a first mounting phase offset angle relative to the phase zero reference, and the laser displacement sensor has a second mounting phase offset angle relative to the phase zero reference.
4. The rolling element precision turning precision error compensation control system of claim 1, wherein the dynamic stiffness modeling module comprises: the data preprocessing unit is used for denoising the workpiece clamping profile signal and fitting the reference circle, and calculating the radial deviation relative to the reference circle; And the stiffness map generating unit is used for calculating stiffness values of the workpiece under different rotation angles by utilizing a nonlinear mapping function according to the nominal radial stiffness of the workpiece material and the radial deviation amount to generate the circumferential dynamic stiffness distribution model.
5. The system for compensating the precision turning error of the rolling bodies according to claim 4, wherein the stiffness map generating unit calculates the stiffness values of the workpiece at different rotation angles by mapping the ratio of the radial deviation amount to the normalization factor by using a hyperbolic tangent function, multiplying the mapping result by a stiffness fluctuation coefficient, adding the stiffness fluctuation coefficient to a unit value, and multiplying the added result by the nominal radial stiffness to obtain the stiffness value at the corresponding angle.
6. The rolling element precision turning precision error compensation control system of claim 1, wherein the angular domain phase coupling module comprises: the angle conversion unit is used for receiving the instantaneous angular speed fed back by the main shaft rotary encoder signal and calculating the current main shaft rotation angle under the workpiece coordinate system through time integration; The phase alignment unit is used for aligning the radial runout signal of the main shaft and the three-way cutting force signal to the current main shaft rotation angle according to the physical included angle of each sensor installation position relative to the cutting point; And the characteristic synthesis unit is used for calculating resultant force modulus of the three-way cutting force signal in a cutting plane, indexing a stiffness value corresponding to the current angle from the circumferential dynamic stiffness distribution model, and dividing the resultant force modulus by the stiffness value to obtain the stiffness modulation deformation.
7. The system of claim 6 wherein the feature synthesis unit calculates the equivalent spindle geometry error by obtaining the spindle radial runout signals aligned to the X-direction and the Y-direction of the current spindle rotation angle, multiplying the spindle radial runout signals in the X-direction by the cosine of the current spindle rotation angle, multiplying the spindle radial runout signals in the Y-direction by the sine of the current spindle rotation angle, and adding the products of the two to obtain the equivalent spindle geometry error.
8. The rolling body precision turning precision error compensation control system according to claim 1, the error prediction module is characterized by comprising: The characteristic sequence construction unit is used for combining the rigidity modulation deformation of the current moment and a plurality of angle step sizes in the past, the equivalent main shaft geometric error, the workpiece material hardness parameter and the main shaft rotating speed parameter to form a time sequence characteristic matrix; The network reasoning unit is used for inputting the time sequence feature matrix into the long-short-time memory network model, updating the cell state through a gating mechanism of a forgetting gate, an input gate and an output gate, and mapping to obtain the roundness error prediction value.
9. The system for compensating the precision turning error of the rolling element according to claim 8, wherein the network reasoning unit calculates the activation values of the forgetting gate, the input gate and the output gate by splicing the hidden state at the previous moment with the feature vector in the time sequence feature matrix at the current moment, multiplying the spliced vector with the corresponding weight matrix and adding a bias term, and applying a Sigmoid activation function to the calculation result.
10. The rolling element precision turning precision error compensation control system of claim 1, wherein the compensation execution module comprises: a deviation calculation unit for calculating a numerical deviation between a zero-value target and the roundness error prediction value; The control quantity generation unit is used for carrying out proportional, integral and differential operation on the numerical deviation by adopting a PID control algorithm to generate a control compensation quantity for counteracting errors; The instruction correction execution unit is used for reading the original interpolation instruction of the numerical control system in real time, and using the control compensation quantity as the offset to modify the target position coordinate of the original interpolation instruction.

Description

Rolling element precision turning precision error compensation control system Technical Field The invention relates to the technical field of precision machining control, in particular to a precision turning precision error compensation control system for rolling bodies. Background The roundness precision of the rolling bodies serving as core bearing elements of the precision bearing directly influences the rotation precision, the vibration noise level and the fatigue life of the whole bearing. In the hard turning process for large-size rolling bodies (such as wind power bearing rollers and high-speed railway axle box bearing rollers), ensuring the micron-scale roundness precision of finished products is a key and very challenging technological requirement. Conventional turning error compensation techniques rely primarily on off-line inspection or open-loop compensation based on static models. Such methods generally assume that the workpiece is a rigid body during machining, or that only geometrical errors of the machine tool itself are considered, while complex dynamic physical interactions during cutting are ignored. However, in a practical precision hard turning process, the workpiece is subjected to the clamping action of a powerful three-jaw chuck, and the radial stiffness distribution in the circumferential direction thereof exhibits significant non-uniformity. The method is characterized in that the rigidity of the contact area of the clamping jaws is high, and the rigidity of the suspension area between the clamping jaws is low. When the cutting tool cuts circumferentially, a constant cutting force acts on the workpiece surface with continuously changing rigidity, which inevitably leads to periodically fluctuating elastic yielding deformation, and the remapping error caused by the 'rigidity-force' coupling effect is one of the important reasons for causing roundness deviation of the rolling bodies. The existing error compensation scheme cannot effectively solve the problem of time-varying rigidity. In part of the schemes, although cutting force monitoring is introduced, the force signal is often simply used as a threshold value for monitoring, or a fixed rigidity coefficient is adopted for linear conversion, so that the real deformation characteristics of the workpiece under different rotation angles cannot be reflected. In addition, the existing multi-sensor monitoring system generally collects data independently, and cannot properly solve the problem of phase difference of different sensors (such as a displacement sensor installed at a spindle end and a dynamometer installed at a base) in a spatial physical position. The time-space asynchronism can lead to phase dislocation of the physical phenomenon of the collected error signal and the actual cutting point, further lead to delayed compensation action or even generate reverse overcompensation, and hardly meet the severe requirement of high-end rolling body manufacturing on submicron precision. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a rolling body precise turning precision error compensation control system, which solves the problems that the existing rolling body turning error compensation technology fails to consider the non-uniform distribution characteristic of the circumferential rigidity of a workpiece caused by clamping, and the multisource sensor has phase non-synchronization on the physical space so as to cause the elastic deformation characterization distortion and compensation hysteresis of a cutting point. In order to achieve the above purpose, the invention is realized by the following technical scheme: the invention provides a rolling body precise turning precision error compensation control system, which comprises: the multi-source heterogeneous sensing module is used for collecting a radial runout signal, a three-way cutting force signal, a workpiece clamping contour signal and a main shaft rotary encoder signal of the main shaft in real time; The dynamic stiffness modeling module is used for constructing a circumferential dynamic stiffness distribution model distributed along the circumferential direction of the workpiece according to the workpiece clamping profile signal; The angle domain phase coupling module is used for mapping the spindle radial runout signal and the three-way cutting force signal to a workpiece rotation angle domain by utilizing the spindle rotation encoder signal, calculating the ratio of the angle domain cutting force to the corresponding phase stiffness value to obtain a stiffness modulation deformation, and outputting a comprehensive feature vector containing the stiffness modulation deformation and an equivalent spindle geometric error; The error prediction module is used for inputting the comprehensive feature vector into a pre-trained long-short-time memory network model, and predicting and outputting a roundness error prediction value of the next angle st