CN105653842A - Method for constructing geometric error model of rolling guide feed system - Google Patents

Abstract

In allusion to the machine tool feed systems taking linear rolling guides as bearing and guiding mechanisms, the invention discloses a method for modeling force deformation error of a feed system through comprehensively considering the coupling influences, on the precision of the feed system, caused by the precision and rigidity of the a guide under the action of external force. The method comprises the following steps: firstly estimating the contact rigidity of the guide through an equivalent load method; establishing a load balance equation of a worktable taking sliding blocks as supports; determining a geometric deformation relationship among the sliding blocks according to rigidity assumption of the worktable; and complementing an equation according to the physical relationship series between the deformation and the force, and finally establishing an equation to solve the force deformation error of the feed system. According to the method, the blank of the coupling influences, on the precision of the system, caused by the precision and rigidity of the guide under the action of external force is filled, and favorable application prospect is provided for researching the force error of machine tools.

Description

The construction process of a kind of rolling guide feed system geometric error model

Technical field

The present invention relates to machine tool feed system stiffness and Research on Accuracy field, particularly relate to the construction process of rolling guide feed system geometric error model and the acquisition methods of rolling guide feed system geometric error.

Background technology

The feed system of numerically-controlled machine is the key components affecting numerically-controlled machine precision, and numerically-controlled machine working accuracy, precision stability and reliability are had great impact by its quality and performance. Feed system geometric accuracy can be called again geometric error, main from self error of feed system component, and the distortion of the feed system parts caused such as produce to be forced to coordinate due to Form and position error between external force, heat, feed system parts and assembling error, these distortion finally can be delivered to worktable or main shaft, forms the geometric error of feed system.

In the space that Descartes's system of coordinates describes, the motion of numerically-controlled machine can be weighed in 6 geometric errors produced by 6 degree of freedom directions. The function of guide rail is just 5 degree of freedom of controls movement parts, and only along needing direction to move, therefore guiding error is considered as the main source of feed system geometric error.

Linear rolling track has that autokinesis height, positioning precision height, tractive force are little, little, lubrication simple and convenient for maintenance of wearing and tearing, instead of traditional sliding straight guide rail (except heavy duty lathe) gradually, become the important functional component of today's numerical control lathe. Guide precision comprises guide rail guiding accuracy, rigidity etc. Its middle guide rigidity comprises guide rail stiffness by itself and contact stiffness, owing to Structure deformation belongs to weak separation link compared to guide rail stiffness by itself, and the therefore contact stiffness of usual referred to guide rail rigidity guide rail slide block pair in other words. At guide precision on, in the impact of feed system precision, often only emphasizing that guide rail guiding accuracy is on the parallelism affected between guide rail linearity, guide rail of motion precision. For guide rail rigidity on the impact of feed system precision, being partial to static analysis mainly through the analysis of feed system load and each slide block being subject to the distribution of power, by the analysis of the secondary rigidity of guide rail slide block, solving feed system motion precision. The impact of feed system precision is the result of guide rail guiding accuracy and guide rail rigidity acting in conjunction by guide precision, the mechanism pointing out that system precision is affected by guide precision is failed in current research, the impact of system precision is then assumed that joint portion contact pressure is uniformly distributed by external force effect, it does not have considers that guide rail self precision causes and is forced to coordinate the distortion produced and contact load.

Summary of the invention

The present invention is intended to for linear rolling track as the machine tool feed system of carrying with guiding mechanism, consider that guide precision and rigidity are under external force to the coupling influence of feed system precision, it is proposed to the construction process of a kind of rolling guide feed system geometric error model and the acquisition methods of rolling guide feed system geometric error comprehensively.

The above-mentioned purpose of the present invention is realized by the technology feature of independent claim, dependent claims by select else or favourable in the way of develop the technology feature of independent claim.

For reaching above-mentioned purpose, the present invention proposes the construction process of a kind of rolling guide feed system geometric error model, comprise: first by equivalent load method, guide rail contact stiffness is estimated, secondly set up using slide block as the worktable stress balance equation supported, then assume to determine each slide block geometry deformation relationship according to the rigidity of worktable, closing series according to the physics between distortion and power and supplement equation, last simultaneous equations solve the force deformation error of feed system.

As long as it is to be understood that aforementioned concepts and all combinations of extra design of describing in further detail below can be regarded as a part for subject matter of the present disclosure when such design is not conflicting. In addition, all combinations of claimed theme are all regarded as a part for subject matter of the present disclosure.

Foregoing and other aspect, embodiment and feature that the present invention instructs can be understood by reference to the accompanying drawings from the following description more comprehensively. Feature and/or the useful effect of other additional aspect such as illustrative embodiments of the present invention will be obvious in the following description, or by the practice of the embodiment instructed according to the present invention is learnt.

Accompanying drawing explanation

Accompanying drawing is not intended to draw in proportion. In the accompanying drawings, each illustrating in each figure be identical or approximately uniform integral part can represent with identical label. For clarity, in each figure, not each integral part is all labeled. Now, the embodiment of all respects of the present invention also will be described with reference to accompanying drawing by example, wherein:

Fig. 1 is the schema of the feed system error model of the present invention

Fig. 2 is feed system guide rail-countertop unit schematic diagram.

Fig. 3 is that guide rail slide block is secondary radial by load schematic diagram.

Fig. 4 is moment schematic diagram suffered by guide rail slide block pair.

Fig. 5 is the radial support reaction schematic diagram of each slide block.

Fig. 6 is position, slide block z-axis direction skew schematic diagram.

Fig. 7 is position, slide block y-axis direction skew schematic diagram.

Embodiment

In order to more understand the technology contents of the present invention, especially exemplified by specific embodiment and coordinate institute's accompanying drawings to be described as follows.

Each side with reference to the accompanying drawings to describe the present invention in the disclosure, shown in the drawings of the embodiment of many explanations. Embodiment of the present disclosure must not be intended to comprise all aspects of the present invention. It is to be understood that, multiple design presented hereinbefore and embodiment, and those designs described in more detail below and enforcement mode can in many ways in any one is implemented, this should be design disclosed in this invention and embodiment is not limited to any enforcement mode. In addition, aspects more disclosed by the invention can be used alone, or uses with any appropriately combined of other aspects disclosed by the invention.

Preferred embodiment according to the present invention, the guide rail-countertop unit of a kind of Four-slider is carried out force deformation error and carries out modeling by the present invention, as shown in Figure 2, it may also be useful to the guide rail slide block pair of middle precompressed is similar to linear slide block force deformation feature more to obtain. Model middle guide precision and worktable are input by masterpiece, and wherein guide precision comprises the starting position error of slide block and the contact stiffness of guide rail slide block pair, and worktable is subject to power can be converted into point of application in the power of table core and torque. The geometric error that output slide block and worktable are finally formed, namely exporting of model is the worktable error under guide precision and the power of being subject to affect jointly, i.e. 5 errors of other except axial positioning errors.

Shown in composition graphs 1, the construction process of rolling guide feed system geometric error model specifically comprises the following steps:

Steps A: the guide rail contact stiffness modeling of equivalent load method, concrete steps are as follows:

Steps A-1: set up system of coordinates direction, taking axial motion direction as x-axis, the radial vertical direction being perpendicular to x-axis is z-axis, is laterally y-axis.

Steps A-2: calculate slide block pair according to the radial stiffness K of linearization process by equivalent load method and rotate rigidity.

Taking contact angle as 45 ��, the slide block type that raceway is transversely all symmetrically distributed with longitudinal direction is example, and identical with horizontal rigidity according to formula its longitudinal rigidity known, namely 4 direction supporting capacitys are identical, as shown in Figure 3. Assume that the secondary longitudinal rigidity of slide block is K, i.e. K with horizontal rigidity value_z=K_y=K. The ability of slide block opposing moment distortion is called rotation rigidity, as shown in Figure 4, represents rotation stiffness K with K_x',K_y',K_z'��

When slide block is subject to axial torque M_CTime, slide block produces torsion(al)angle distortion ��_x. Effect is equivalent to often row's raceway and bears the power F being perpendicular to raceway and slide block axle line. If raceway transverse pitch l₂, the longitudinal spacing l of raceway₂, raceway and slide block axle line and horizontal direction angle are that ��, F can be analyzed to longitudinal component F_zWith horizontal component F_y. Assume that horizontal and vertical same side two raceway meets the hypothesis of linear rigidity, and single side two raceway rigidity is the half of integral rigidity, can obtain the relation in following formula:

Torque M_CIt is out of shape �� with torsion(al)angle_xRelation can represent and be

Torsional stiffness around x-axis can represent

When slide block is subject to pitching torque M_ATime, slide block produces angle of pitch distortion ��_y. Assume longitudinally to meet linear rigidity, and disregard the discrete arrangement of ball. Reactive force can be equivalent to the linear gradient load distributed vertically, and race length is that l force deformation relation can represent and is

Torque M_AIt is out of shape �� with torsion(al)angle_yRelation can represent and be

Pitch stiffness around y-axis can represent

With reason, rocking rigidity and can represent and be around z-axis

Step B: set up the deformation relationship between worktable stress balance equation and each slide block:

Step B-1: with F_x,F_y,F_z,M_x,M_y,M_zRepresent the external force acting on table core, with R_i, S_iRepresent that guide rail slide block side effect is at the support reaction in worktable z direction and y direction, as shown in Figure 5, M_ix,M_iy,M_izRepresent the torque that slide block three directions produce due to distortion, wherein (i=1,2,3,4).

Step B-2: equilibrium establishment equation:

Step B-3: owing to worktable rigidity is much larger than contact stiffness, worktable is considered as rigid body. Each slide block can be represented by Fig. 6, Fig. 7 relative to the position relation of benchmark, as follows by the Representation Equation:

In formula, ��_iRepresent that the z of slide block relative to reference line is to skew amount, ��_i' represent that the y of slide block relative to reference line is to skew amount, ��_ix,��_iy,��_izRepresent the corner of each slide block relative datum axis, wherein (i=1,2,3,4).

Step C: set up according to the secondary rigidity of guide rail slide block and guiding error and supplement equation:

Slide block initial offset is ��_0i,��'_0i,��_0ix,��_0iy,��_0iz, relative offset amount ��_ri,��'_ri,��_rix,��_riy,��_rizRepresent, as shown in Figure 6, Figure 7, wherein (i=1,2,3,4). Linear relationship is held in the pose change of relative offset amount and slide block, can obtain

Step D: Simultaneous Equations, solves each slide block stressing conditions:

In formula,Representing that 4 slide blocks are suffered around the resultant bending moment of x-axis and y-axis direction respectively, the moment of flexure suffered by each slide block can be expressed from the next

In formula,Representing the suffered resultant bending moment around z-axis direction of 4 slide blocks, the moment of flexure suffered by each slide block can be expressed from the next

Step e: solve slide block and geometric error that worktable is finally formed:

Step e-1: the relative offset amount solving slide block

[��_ri,��'_ri,��_rix,��_riy,��_riz]^T=K^-1[R_i,S_i,M_ix,M_iy,M_iz]^T

Step e-2: solve the geometric error that worktable is finally formed

According to record of the present disclosure, the those of ordinary skill of this area can go out corresponding program according to its content development and run in a computer system, thus realizes every step and the effect of the embodiment of the construction process of aforementioned rolling guide feed system geometric error model.

Although the present invention with better embodiment disclose as above, so itself and be not used to limit the present invention. Persond having ordinary knowledge in the technical field of the present invention, without departing from the spirit and scope of the present invention, when being used for a variety of modifications and variations. Therefore, protection scope of the present invention is when being as the criterion depending on those as defined in claim.

Claims (3)

1. the construction process of a rolling guide feed system geometric error model, it is characterized in that, comprise: first by equivalent load method, guide rail contact stiffness is estimated, secondly set up using slide block as the worktable stress balance equation supported, then assume to determine each slide block geometry deformation relationship according to the rigidity of worktable, closing series according to the physics between distortion and power and supplement equation, last simultaneous equations solve the force deformation error of feed system.

2. the construction process of rolling guide feed system geometric error model according to claim 1, it is characterised in that, the realization of the method specifically comprises the following steps:

Steps A: the guide rail contact stiffness modeling of equivalent load method, concrete steps comprise following A-1 to A-2:

Steps A-1: set up system of coordinates direction, taking axial motion direction as x-axis, the radial vertical direction being perpendicular to x-axis is z-axis, is laterally y-axis;

Steps A-2: calculate slide block pair according to the radial stiffness K of linearization process by equivalent load method and rotate rigidity; Be 45 �� for contact angle, raceway transversely with the slide block type being longitudinally all symmetrically distributed, its longitudinal rigidity is identical with horizontal rigidity, and namely 4 direction supporting capacitys are identical, it is assumed that the secondary longitudinal rigidity of slide block is K, i.e. K with transverse direction rigidity value_z=K_y=K, the ability of slide block opposing moment distortion is called rotation rigidity, rotates stiffness K_x',K_y',K_z'��

When slide block is subject to axial torque M_CTime, slide block produces torsion(al)angle distortion ��_x, effect is equivalent to often row's raceway and bears the power F being perpendicular to raceway and slide block axle line, if raceway transverse pitch l₂, the longitudinal spacing l of raceway₂, raceway and slide block axle line and horizontal direction angle are that ��, F can be analyzed to longitudinal component F_zWith horizontal component F_y, it is assumed that horizontal and vertical same side two raceway meets the hypothesis of linear rigidity, and single side two raceway rigidity is the half of integral rigidity, can obtain the relation in following formula:

$\left\{\begin{array}{c}{M}_C=4\·\frac{l_1}{2}\·F_z+4\·\frac{l_2}{2}\·F_y\\ 2F_z=\frac{K_z}{2}\·{\mathrm{\δ}}_z\\ 2F_y=\frac{K_y}{2}\·{\mathrm{\δ}}_y\\ {\mathrm{\δ}}_z=\frac{l_1}{2}\·{\mathrm{\φ}}_x\\ {\mathrm{\δ}}_y=\frac{l_2}{2}\·{\mathrm{\φ}}_x\end{array}\right.$

Torque M_CIt is out of shape �� with torsion(al)angle_xRelation can represent and be:

$M_C=\frac{K}{4}(l_1^2+l_2^2){\mathrm{\φ}}_x$

Torsional stiffness around x-axis can represent:

$K_{x^{\′}}=\frac{K}{4}(l_1^2+l_2^2)$

When slide block is subject to pitching torque M_ATime, slide block produces angle of pitch distortion ��_y, it is assumed that longitudinally meeting linear rigidity, and disregard the discrete arrangement of ball, reactive force can be equivalent to the linear gradient load distributed vertically, race length is that l force deformation relation can represent and is:

$\left\{\begin{array}{c}{M}_A={\∫}_{-\frac{l}{2}}^{\frac{l}{2}}q\left(x\right)xdx\\ q\left(x\right)=\frac{K_z}{l}{\mathrm{\δ}}_z\left(x\right)\\ {\mathrm{\δ}}_z\left(x\right)={\mathrm{\φ}}_y\·x\end{array}\right.$

Torque M_AIt is out of shape �� with torsion(al)angle_yRelation can represent and be:

$M_A=\frac{K}{12}{l}^2{\mathrm{\φ}}_y$

Pitch stiffness around y-axis can represent:

$K_{y^{\′}}=\frac{l^2}{12}K$

With reason, rocking rigidity and can represent and be around z-axis:

$K_{z^{\′}}=\frac{l^2}{12}K$

Step B: set up the deformation relationship between worktable stress balance equation and each slide block, comprise the following steps B-1 to B-3:

Step B-1: with F_x,F_y,F_z,M_x,M_y,M_zRepresent the external force acting on table core, with R_i, S_iRepresent that guide rail slide block side effect is at the support reaction in worktable z direction and y direction, M_ix,M_iy,M_izRepresent the torque that slide block three directions produce, wherein i=1,2,3,4 due to distortion;

Step B-2: equilibrium establishment equation:

$\left\{\begin{array}{c}{R}_1+R_2+R_3+R_4+F_z=0\\ S_1+S_2+S_3+S_4+F_y=0\\ \frac{L_2}{2}(R_1+R_2-R_3-R_4)+\underset{i=1}{\overset{4}{\Σ}}{M}_{ix}+M_x=0\\ \frac{L_1}{2}(-R_1+R_2-R_3+R_4)+\underset{i=1}{\overset{4}{\Σ}}{M}_{iy}+M_y=0\\ \frac{L_1}{2}(S_1-S_2+S_3-S_4)+\underset{i=1}{\overset{4}{\Σ}}{M}_{iz}+M_z=0\end{array}\right.$

Step B-3: owing to worktable rigidity is much larger than contact stiffness, worktable is considered as rigid body, as follows by the Representation Equation:

$\left\{\begin{array}{c}\frac{{\mathrm{\δ}}_1+{\mathrm{\δ}}_4}{2}=\frac{{\mathrm{\δ}}_2+{\mathrm{\δ}}_3}{2}\\ {\mathrm{\δ}}_1^{\′}={\mathrm{\δ}}_3^{\′}\\ {\mathrm{\δ}}_2^{\′}={\mathrm{\δ}}_4^{\′}\\ {\mathrm{\φ}}_{1x}={\mathrm{\φ}}_{2x}={\mathrm{\φ}}_{3x}={\mathrm{\φ}}_{4x}={\mathrm{\Φ}}_x=\frac{{\mathrm{\δ}}_1-{\mathrm{\δ}}_3}{L_2}=\frac{{\mathrm{\δ}}_2-{\mathrm{\δ}}_4}{L_2}\\ {\mathrm{\φ}}_{1y}={\mathrm{\φ}}_{2y}={\mathrm{\φ}}_{3y}={\mathrm{\φ}}_{4y}={\mathrm{\Φ}}_y=\frac{{\mathrm{\δ}}_3-{\mathrm{\δ}}_4}{L_1}=\frac{{\mathrm{\δ}}_1-{\mathrm{\δ}}_2}{L_1}\\ {\mathrm{\φ}}_{1z}={\mathrm{\φ}}_{2z}={\mathrm{\φ}}_{3z}={\mathrm{\φ}}_{4z}={\mathrm{\Φ}}_z=\frac{{\mathrm{\δ}}_2^{\′}-{\mathrm{\δ}}_1^{\′}}{L_1}=\frac{{\mathrm{\δ}}_4^{\′}-{\mathrm{\δ}}_3^{\′}}{L_1}\end{array}\right.$

In formula, ��_iRepresent that the z of slide block relative to reference line is to skew amount, ��_i' represent that the y of slide block relative to reference line is to skew amount, ��_ix,��_iy,��_izRepresent the corner of each slide block relative datum axis, wherein i=1,2,3,4;

Step C: set up according to the secondary rigidity of guide rail slide block and guiding error and supplement equation:

Slide block initial offset is ��_0i,�ġ�_0i,��_0ix,��_0iy,��_0iz, relative offset amount ��_ri,�ġ�_ri,��_rix,��_riy,��_rizRepresent, wherein (i=1,2,3,4). Linear relationship is held in the pose change of relative offset amount and slide block, can obtain

$\left\{\begin{array}{c}{R}_i=K_z\·{\mathrm{\δ}}_{ri}=K_z\·({\mathrm{\δ}}_i-{\mathrm{\δ}}_{0i})\\ S_i=K_y\·{\mathrm{\δ}}_{ri}^{\′}=K_y\·({\mathrm{\δ}}_i^{\′}-{\mathrm{\δ}}_{0i}^{\′})\\ M_{ix}=K_{x^{\′}}\·{\mathrm{\φ}}_{rix}=K_{x^{\′}}\·({\mathrm{\φ}}_{ix}-{\mathrm{\φ}}_{0ix})\\ M_{iy}=K_{y^{\′}}\·{\mathrm{\φ}}_{riy}=K_{y^{\′}}\·({\mathrm{\φ}}_{iy}-{\mathrm{\φ}}_{0iy})\\ M_{iz}=K_{z^{\′}}\·{\mathrm{\φ}}_{riz}=K_{z^{\′}}\·({\mathrm{\φ}}_{iz}-{\mathrm{\φ}}_{0iz})\end{array}\right.$

Step D: Simultaneous Equations, solves each slide block stressing conditions:

$\left[\begin{array}{c}{R}_1\\ R_2\\ R_3\\ R_4\\ \underset{i=1}{\overset{4}{\Σ}}{M}_{ix}\\ \underset{i=1}{\overset{4}{\Σ}}{M}_{iy}\end{array}\right]={\left[\begin{array}{cccccc}1& 1& 1& 1& 0& 0\\ \frac{L_2}{2}& \frac{L_2}{2}& -\frac{L_2}{2}& -\frac{L_2}{2}& 1& 0\\ -\frac{L_1}{2}& \frac{L_1}{2}& -\frac{L_1}{2}& \frac{L_1}{2}& 0& 1\\ \frac{1}{K_z}& -\frac{1}{K_z}& -\frac{1}{K_z}& \frac{1}{K_z}& 0& 0\\ -\frac{4}{K_z\·L_2}& 0& \frac{4}{K_z\·L_2}& 0& \frac{1}{K_{x^{\′}}}& 0\\ 0& 0& -\frac{4}{K_z\·L_1}& \frac{4}{K_z\·L_1}& 0& \frac{1}{K_{y^{\′}}}\end{array}\right]}^{-1}\left[\begin{array}{c}-F_z\\ -M_x\\ -M_y\\ -({\mathrm{\δ}}_{01}-{\mathrm{\δ}}_{02}-{\mathrm{\δ}}_{03}+{\mathrm{\δ}}_{04})\\ \frac{4({\mathrm{\δ}}_{01}-{\mathrm{\δ}}_{03})}{L_2}-\underset{i=1}{\overset{4}{\Σ}}{\mathrm{\φ}}_{0ix}\\ \frac{4({\mathrm{\δ}}_{03}-{\mathrm{\δ}}_{04})}{L_1}-\underset{i=1}{\overset{4}{\Σ}}{\mathrm{\φ}}_{0iy}\end{array}\right]$

In formula,Representing that 4 slide blocks are suffered around the resultant bending moment of x-axis and y-axis direction respectively, the moment of flexure suffered by each slide block can be expressed from the next:

$\left\{\begin{array}{c}{M}_{ix}=\frac{\underset{i=1}{\overset{4}{\Σ}}{M}_{ix}}{4}+\frac{\underset{i=1}{\overset{4}{\Σ}}{\mathrm{\φ}}_{0ix}}{4}-{\mathrm{\φ}}_{0ix}\\ M_{iy}=\frac{\underset{i=1}{\overset{4}{\Σ}}{M}_{iy}}{4}+\frac{\underset{i=1}{\overset{4}{\Σ}}{\mathrm{\φ}}_{0iy}}{4}-{\mathrm{\φ}}_{0iy}\end{array}\right.$

$\left[\begin{array}{c}{S}_1\\ S_2\\ S_3\\ S_4\\ \underset{i=1}{\overset{4}{\Σ}}{M}_{iz}\end{array}\right]={\left[\begin{array}{ccccc}1& 1& 1& 1& 0\\ \frac{L_1}{2}& -\frac{L_1}{2}& \frac{L_1}{2}& -\frac{L_1}{2}& 1\\ \frac{1}{K_y}& 0& -\frac{1}{K_y}& 0& 0\\ 0& \frac{1}{K_y}& 0& -\frac{1}{K_y}& 0\\ \frac{4}{K_y\·L_1}& -\frac{4}{K_y\·L_1}& 0& 0& \frac{1}{K_{z^{\′}}}\end{array}\right]}^{-1}\left[\begin{array}{c}-F_y\\ -M_z\\ -({\mathrm{\δ}}_{01}^{\′}-{\mathrm{\δ}}_{03}^{\′})\\ -({\mathrm{\δ}}_{02}^{\′}-{\mathrm{\δ}}_{04}^{\′})\\ \frac{4({{\mathrm{\δ}}^{\′}}_{02}-{{\mathrm{\δ}}^{\′}}_{01})}{L_1}-\underset{i=1}{\overset{4}{\Σ}}{\mathrm{\φ}}_{0iz}\end{array}\right]$

In formula,Representing the suffered resultant bending moment around z-axis direction of 4 slide blocks, the moment of flexure suffered by each slide block can be expressed from the next

$M_{iz}=\frac{\underset{i=1}{\overset{4}{\Σ}}{M}_{iz}}{4}+\frac{\underset{i=1}{\overset{4}{\Σ}}{\mathrm{\φ}}_{0iz}}{4}-{\mathrm{\φ}}_{0iz}$

Step e: solve slide block and geometric error that worktable is finally formed, comprise E-1 to E-2:

Step e-1: the relative offset amount solving slide block

[��_ri,�ġ�_ri,��_rix,��_riy,��_riz]^T=K^-1[R_i,S_i,M_ix,M_iy,M_iz]^T

Step e-2: solve the geometric error that worktable is finally formed

$\left\{\begin{array}{c}{\mathrm{\δ}}_o=({\mathrm{\δ}}_1+{\mathrm{\δ}}_4)/2=({\mathrm{\δ}}_2+{\mathrm{\δ}}_3)/2\\ {\mathrm{\δ}}_o^{\′}=({\mathrm{\δ}}_1^{\′}+{\mathrm{\δ}}_2^{\′})/2=({\mathrm{\δ}}_3^{\′}+{\mathrm{\δ}}_4^{\′})/2\\ {\mathrm{\Φ}}_x=({\mathrm{\δ}}_3-{\mathrm{\δ}}_1)/L_2=({\mathrm{\δ}}_4-{\mathrm{\δ}}_2)/L_2\\ {\mathrm{\Φ}}_y=({\mathrm{\δ}}_4-{\mathrm{\δ}}_3)/L_1=({\mathrm{\δ}}_2-{\mathrm{\δ}}_1)/L_1\\ {\mathrm{\Φ}}_z=({\mathrm{\δ}}_2^{\′}-{\mathrm{\δ}}_1^{\′})/L_1=({\mathrm{\δ}}_4^{\′}-{\mathrm{\δ}}_3^{\′})/L_1\end{array}\right..$

3. the geometric error acquisition methods of a rolling guide feed system, it is characterised in that, comprise the following steps:

Step 1, build rolling guide feed system geometric error model according to claim 1 or claim 2;

Step 2, taking guide precision and worktable by masterpiece as input, input the model that described step 1 is set up, the geometric error that output slide block and worktable are finally formed, wherein guide precision comprises the starting position error of slide block and the contact stiffness of guide rail slide block pair, and worktable is converted into point of application in the power of table core and torque by power.