阅读说明：本技术 应用于丝杆热形变自校正系统的补偿算法 (Compensation algorithm applied to lead screw thermal deformation self-correction system ) 是由 唐东雷 于 2019-08-03 设计创作，主要内容包括：本发明公开了一种应用于丝杆热形变自校正系统的补偿算法,涉及丝杆传动技术领域,其技术方案要点是,包括：S1-1、获取丝杆的形变量；S1-2、根据机床的机械坐标参数、丝杆参数以及实际干扰参数计算得到实际加工时丝杆所在的坐标,并命名为初始宏变量；S1-2-1、判断初始宏变量是否落入一预设的自检参考值,是则进行补偿计算,否则输出报警信息；S1-2-2、补偿计算,其包括判断初始宏变量属于哪一个赋值范围；S1-2-3、根据初始宏变量所属的赋值范围将手动输入系数赋值给初始宏变量得到特定系数；S2、将丝杆的形变量乘以特定系数得到丝杆传动的实际补偿值。本发明可计算丝杆的实际补偿值,用于供热形变自校正系统得到校正数据。(The invention discloses a compensation algorithm applied to a lead screw thermal deformation self-correction system, which relates to the technical field of lead screw transmission, and the key point of the technical scheme is that the compensation algorithm comprises the following steps: s1-1, acquiring the deformation quantity of the screw rod; s1-2, calculating according to the mechanical coordinate parameters, the screw rod parameters and the actual interference parameters of the machine tool to obtain the coordinates of the screw rod during actual processing, and naming the coordinates as initial macro variables; s1-2-1, judging whether the initial macro variable falls into a preset self-checking reference value, if so, performing compensation calculation, otherwise, outputting alarm information; s1-2-2, compensation calculation, which comprises judging which assignment range the initial macro variable belongs to; s1-2-3, assigning the manual input coefficient to the initial macro variable according to the assignment range of the initial macro variable to obtain a specific coefficient; and S2, multiplying the deformation quantity of the screw rod by a specific coefficient to obtain an actual compensation value of the screw rod transmission. The invention can calculate the actual compensation value of the screw rod and is used for the heat supply deformation self-correcting system to obtain the correction data.)

1. A compensation algorithm applied to a lead screw thermal deformation self-correction system is characterized by comprising the following steps:

s1-1, acquiring the deformation quantity of the screw rod;

s1-2, calculating according to the mechanical coordinate parameters, the screw rod parameters and the actual interference parameters of the machine tool to obtain the coordinates of the screw rod during actual processing, and naming the coordinates as initial macro variables;

s1-2-1, judging whether the initial macro variable falls into a preset self-checking reference value, if so, performing compensation calculation, otherwise, outputting alarm information;

s1-2-2, compensation calculation, wherein the compensation calculation comprises the steps of judging which assignment range the initial macro variable belongs to, the assignment range is preset, and each assignment range is preset with a manual input coefficient;

s1-2-3, assigning the manual input coefficient to the initial macro variable according to the assignment range of the initial macro variable to obtain a specific coefficient;

and S2, multiplying the deformation quantity of the screw rod by a specific coefficient to obtain an actual compensation value of the screw rod transmission.

2. The compensation algorithm applied to the lead screw thermal deformation self-correction system according to claim 1, characterized in that: the deformation of the screw rod is axial variation.

3. The compensation algorithm applied to the lead screw thermal deformation self-correction system according to claim 1, characterized in that: the actual disturbance parameter includes one or more of a tool setting coordinate, a tool offset, and a tool wear value.

4. The compensation algorithm applied to the lead screw thermal deformation self-correction system according to claim 1, characterized in that: and calculating the initial macro-variable according to a comprehensive calculation mode, wherein the comprehensive calculation mode comprises the steps of calculating coordinate data of a theoretical screw rod according to mechanical coordinate parameters and screw rod parameters of the machine tool, and superposing the tool setting coordinate, the tool offset and the tool wear value on values of all shafts corresponding to the theoretical coordinate data.

5. The compensation algorithm applied to the lead screw thermal deformation self-correction system according to claim 1, characterized in that: the self-checking reference value comprises total stroke data of the screw rod.

6. The compensation algorithm applied to the lead screw thermal deformation self-correction system according to claim 1, characterized in that: the assignment range is a lead screw interval range and represents an effective range of the use of the corresponding manual input coefficient; the manual input coefficient is the expansion amount proportion of the screw rod in the assigned range, and the assigned range and the manual input coefficient are numerical values obtained by a user according to actual processing verification.

Technical Field

The invention relates to the technical field of screw rod transmission, in particular to a compensation algorithm applied to a screw rod thermal deformation self-correction system.

Background

Nowadays, with the progress of science and technology, people have higher and higher requirements on the machining precision of numerical control machine tools in the manufacturing industry, wherein the transmission precision of a screw rod is an important factor influencing the machining precision of the numerical control machine tools. The screw rod generates heat through friction in the transmission process or is influenced by the temperature of a processing environment, so that the screw rod expands and stretches in the axial direction, and the processing precision of a machine tool is reduced.

Patent publication No. CN 205380496U: the utility model provides a lead screw prestretches structure, includes motor, motor cabinet, shaft coupling, lead screw, preceding seat subassembly of lead screw, back seat subassembly of lead screw, lead screw horizontal installation is between preceding seat subassembly of lead screw and back seat subassembly of lead screw, and motor horizontal installation is on the motor cabinet, and motor output shaft passes through the shaft coupling with the lead screw axle and is connected, and wherein back seat subassembly of lead screw includes adjusting pad, bearing frame, spacer, bearing front end housing, lock nut, bearing, middle inner spacer, middle outer spacer, bearing rear end housing. The adjusting pad is arranged between the bearing seat and the bearing rear end cover, the bearings are arranged on two sides of the screw rod, the two groups of bearings are arranged on two sides of the middle inner spacer sleeve and the middle outer spacer sleeve, and spacer sleeves are further arranged at two ends of the bearings.

The inner ring and the outer ring at one end of the bearing are fixed by a spacer bush and a bearing front end cover, the outer ring of the bearing is fixed by a bearing rear end cover at the other end, and the inner ring of the bearing is locked by a locking nut, so that the pre-tightening and stretching effects are achieved, the stress of the inner ring and the outer ring of the bearing is balanced, and the service life of the bearing is ensured; the pre-tightening stretching amount is controlled by the adjusting pad, so that the stretching amount of the screw rod can be quantitatively controlled to adapt to the pre-tightening amount of the screw rod under different working environments.

According to the technical scheme, the influence of temperature rise on the transmission precision of the screw rod can be reduced, but the use is relatively inconvenient due to the fact that manual adjustment and maintenance are relied on, so that a screw rod thermal deformation self-correcting system is designed, and a new algorithm is correspondingly provided for constructing the system.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a compensation algorithm applied to a thermal deformation self-correction system of a screw rod, which can calculate the actual compensation value of the screw rod and is used for obtaining correction data by the thermal deformation self-correction system.

The technical purpose of the invention is realized by the following technical scheme: a compensation algorithm applied to a lead screw thermal deformation self-correction system comprises the following steps:

s1-1, acquiring the deformation quantity of the screw rod;

s1-2, calculating according to the mechanical coordinate parameters, the screw rod parameters and the actual interference parameters of the machine tool to obtain the coordinates of the screw rod during actual processing, and naming the coordinates as initial macro variables;

s1-2-1, judging whether the initial macro variable falls into a preset self-checking reference value, if so, performing compensation calculation, otherwise, outputting alarm information;

s1-2-2, compensation calculation, wherein the compensation calculation comprises the steps of judging which assignment range the initial macro variable belongs to, the assignment range is preset, and each assignment range is preset with a manual input coefficient;

s1-2-3, assigning the manual input coefficient to the initial macro variable according to the assignment range of the initial macro variable to obtain a specific coefficient;

and S2, multiplying the deformation quantity of the screw rod by a specific coefficient to obtain an actual compensation value of the screw rod transmission.

Through the technical scheme, the method can calculate the actual compensation value of the screw rod, is used for the thermal deformation self-correction system to serve as correction data, ensures the normal use of the system, and reduces the machining error caused by the thermal deformation of the screw rod relatively conveniently and efficiently.

The invention is further configured to: the deformation of the screw rod is axial variation.

Through the technical scheme, errors caused by axial thermal deformation of the screw rod are mainly corrected; because the axial thermal deformation of the screw rod can cause the error in the feeding amount of the screw rod transmission mechanism when the machine tool is processed according to the original parameters, the processing error is increased.

The invention is further configured to: the actual disturbance parameter includes one or more of a tool setting coordinate, a tool offset, and a tool wear value.

Through the technical scheme, the correction system based on the invention has relatively higher correction precision; the invention also considers the influence of factors such as cutter deviation, cutter loss and the like on the machining precision in actual machining.

The invention is further configured to: and calculating the initial macro-variable according to a comprehensive calculation mode, wherein the comprehensive calculation mode comprises the steps of calculating coordinate data of a theoretical screw rod according to mechanical coordinate parameters and screw rod parameters of the machine tool, and superposing the tool setting coordinate, the tool offset and the tool wear value on values of all shafts corresponding to the theoretical coordinate data.

The invention is further configured to: the self-checking reference value comprises total stroke data of the screw rod.

The invention is further configured to: the assignment range is a lead screw interval range and represents an effective range of the use of the corresponding manual input coefficient; the manual input coefficient is the expansion amount proportion of the screw rod in the assigned range, and the assigned range and the manual input coefficient are numerical values obtained by a user according to actual processing verification.

Through the technical scheme, under different processing conditions, namely different screw rod transmission amounts, the compensation amounts respectively correspond to different assignment ranges, and corresponding manual input coefficients are correspondingly arranged during compensation calculation, so that the compensation amounts can be calculated in a segmented manner, and the calculated structure is more accurate; meanwhile, different users can determine the assignment range and the manual input coefficient according to the actual processing conditions of the users, so that the calculated actual compensation value is more accurate and is attached to the devices of the users, and the using effect is better.

In conclusion, the invention has the following beneficial effects:

1. the method comprises the steps of calculating the coordinate of a screw rod during processing by collecting the initial coordinate of the screw rod and integrating actual interference parameters formed by tool deviation, tool abrasion and the like; whether the coordinate of the screw rod in processing accords with a certain assignment range or not is judged, and a specific coefficient belonging to the assignment range is multiplied by the deformation quantity of the screw rod to obtain an actual compensation value so as to be used for constructing a thermal deformation self-correcting system of the screw rod;

2. under different processing conditions, namely different screw rod transmission amounts and different position points used by the loading seat driven by the screw rod, the corresponding manual input coefficients are respectively corresponded, so that the compensation value can be calculated in a sectional mode, and the finally obtained structure is relatively more accurate.

Drawings

FIG. 1 is a schematic flow chart of the present invention.

Detailed Description

The invention is described in detail below with reference to the figures and examples.

The compensation algorithm applied to the screw thermal deformation self-correction system, referring to fig. 1, includes:

s1-1, acquiring the deformation quantity of the screw rod;

s1-2, calculating to obtain the coordinate (the coordinate when the sliding table or the slide way driven by the screw rod is used, namely the displacement) of the screw rod during actual processing according to the mechanical coordinate parameter, the screw rod parameter and the actual interference parameter of the machine tool, and naming the coordinate as an initial macro variable;

s1-2-1, judging whether the initial macro variable falls into a preset self-checking reference value, if so, performing compensation calculation, otherwise, outputting alarm information; the self-checking reference value comprises total stroke data of the screw rod, and whether the screw rod transmission mechanism is abnormal or not is judged through the self-checking reference value; the alarm information may be a text field, for example: TOUCH SENSOR NOT ON;

s1-2-2, compensation calculation, wherein the compensation calculation comprises the steps of judging which assignment range the initial macro variable belongs to, the assignment range is preset, and each assignment range is preset with a manual input coefficient; the assignment range is a lead screw interval range which represents an effective range of the use of a corresponding manual input coefficient, and can be understood as the transmission quantity of a lead screw during actual use or the displacement and position points used by a sliding table driven by the lead screw during processing; manually inputting the coefficient into the expansion amount proportion of the screw rod in the assigned value range; the assignment range and the manual input coefficient are values obtained by a user according to actual processing verification;

s1-2-3, assigning the manual input coefficient to the initial macro variable according to the assignment range of the initial macro variable to obtain a specific coefficient;

and S2, multiplying the deformation quantity of the screw rod by a specific coefficient to obtain an actual compensation value of the screw rod transmission.

The deformation quantity of the screw rod is axial variation, and relatively speaking, the axial deformation of the screw rod can directly cause the machine tool to generate a feeding quantity error when the screw rod transmission mechanism is controlled according to the original processing parameters, so that the processing precision of the machine tool is influenced.

To the detection collection of lead screw axial variation, there are mainly two kinds of modes:

A. a micrometer (which is an option and can also select other distance sensors and the like) is fixed on a machine body of a screw rod transmission mechanism, a measuring head of a measuring needle of the micrometer is abutted against the end surface of a screw rod, the end surface is parallel to a radial section and generally comprises a starting end surface and a tail end surface of the screw rod, and the end surface can also be a surface for a drop point of the measuring needle which is cut on the screw rod subsequently; the output end of the dial indicator is connected with a machine tool NC (numerical control computer) through a data line, and the actual detection value of the screw rod is collected and fed back to the numerical control computer;

B. a distance sensor (such as a laser distance sensor) or other displacement sensing units are fixed on a moving line of a sliding table of the screw rod transmission mechanism and are arranged at the initial end or the tail end side of the sliding table, so that the detection end of the distance sensor faces to a certain datum point on the sliding table.

When the device is used (when the device is cold, namely the temperature of the device is low), the screw rod transmission mechanism is controlled to drive the sliding table (slide way) on the screw rod transmission mechanism to move towards the detection end of the distance sensor according to certain control data so as to perform benchmark test to obtain benchmark parameters; when machining errors caused by thermal deformation of the compensation screw rod need to be corrected, the sliding table can be controlled to move towards the detection end of the distance sensor again according to control data in benchmark test, the distance sensor collects and outputs deviation amount relative to the first time (benchmark test), namely, the axial thermal deformation amount of the screw rod is obtained, and the axial thermal deformation amount can be used for forming a thermal deformation self-correcting system so as to relatively efficiently and conveniently reduce the influence of the thermal deformation of the screw rod on machining precision.

The initial macro-variable calculation needs to consider actual interference parameters including various influence factors which can occur in actual processing such as tool setting coordinates, tool offset, tool wear values, tool length, processing material diameter and the like, the numerical values are confirmed and input by workers according to actual processing verification, and under the use conditions of different stages, the tool wear values and the like need to be correspondingly changed, so that the calculated result is more accurate.

The initial macro-variable may be calculated according to a comprehensive calculation method, where the comprehensive calculation method includes calculating theoretical coordinate data of the screw according to mechanical coordinate parameters and screw parameters of the machine tool, and superimposing the tool setting coordinate, the tool offset, and the tool wear value on values of respective axes corresponding to the theoretical coordinate data, for example: when the abrasion of the cutter is X-axis-1 mm, Y-axis-0.6 mm and Z-axis-1.2 mm, the values are respectively added to the theoretical X-axis, Y-axis and Z-axis of the screw rod correspondingly to obtain the coordinate of the screw rod in actual processing.

After the actual compensation value is calculated, an appointed address is stored in a digital control computer; during subsequent numerical control machining, the actual compensation value (position variation) in the designated address is compensated to the corresponding shaft, so that the thermal deformation self-correction of the screw rod can be realized, or the cold and hot positions of the machine tool can be operated without error, and the machining precision is ensured.

The following is an example of a compensation algorithm:

IF [ #914LE260.0] GOTO124 (# 914 is the initial macro variable, 260 is the self-test reference value)

Explanation: if the macrovariable #914 shows a value less than 260, then jump to procedure N124

GOTO900

Explanation: otherwise jump to procedure N900

N124

IF [ #914LE230.0] GOTO125 (230 is the assignment range, which is less than the total lead screw stroke)

#907= #550 (# 907 is the initial macro variable after assignment, i.e. the specific coefficient; #550 is the manual input coefficient)

GOTO155

N125

#905= #908 #907 (# 905 is actual compensation value, #908 is axial variation of lead screw, namely feedback data of detection device)

IF[ABS[#905]GT#906]GOTO901

#5201=-#905

G28U0

GOTO999

N900

G#33G#32

#3000=1(TOUCH SENSOR NOT ON)

Explanation: display (TOUCH SENSOR NOT ON) alarm

GOTO999

Explanation: a jump to the program N999 ends the overall macro program.

In conclusion, the invention can calculate the actual compensation value of the screw rod, is used for the thermal deformation self-correction system to serve as correction data, ensures the normal use of the system, and reduces the processing error caused by the thermal deformation of the screw rod relatively conveniently and efficiently.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.