High-precision posture measurement error compensation method

Abstract

The present invention provides a high-precision posture measurement error compensation method, comprising: establishing a posture measurement system and a posture compensation system, assembling three displacement sensors in the posture measurement system into the posture compensation system, controlling a linear translation stage in the posture compensation system to move gradually, obtaining measurement fitting curves of the three displacement sensors, controlling a pitch translation stage and a rotation translation stage in the posture compensation system to rotate gradually, determining a pitch angle fitting curve and a yaw angle fitting curve based on the measurement fitting curves, z-axis measurement values ​​measured by the three displacement sensors, a pitch angle measured by the pitch translation stage, and a yaw angle measured by the rotation translation stage, and using the pitch angle fitting curve and the yaw angle fitting curve to respectively perform error compensation for the pitch angle and yaw angle determined in the posture measurement system. The present invention can compensate for signal detection and processing errors and assembly errors, improve the full-range measurement accuracy of the posture measurement system, and achieve high-precision posture measurement.

Description

Technical Field

[0001] The present invention belongs to the field of posture measurement, and in particular relates to a high-precision posture measurement error compensation method. Background Art

[0002] With the proposal of the strategy of building a strong manufacturing nation, the demand for posture and interoperability detection in application fields such as major strategic equipment and mechanical precision manufacturing is constantly increasing. It is crucial to stably control the posture and interoperability of key components of high-precision and major strategic equipment within a reasonable range to improve product performance and safety.

[0003] Among them, contact displacement measurement systems have significant advantages such as simple structure, high measurement accuracy, and reliability. However, the measurement results of existing posture measurement systems still suffer from signal detection and processing errors and assembly errors. Summary of the Invention

[0004] The present invention provides a high-precision posture measurement error compensation method to solve the problem that the measurement results of the existing posture measurement system do not compensate for signal detection and processing errors and assembly errors.

[0005] According to a first aspect of an embodiment of the present invention, a high-precision posture measurement error compensation method is provided, comprising:

[0006] Step S100: Establish a posture measurement system including three displacement sensors, wherein the horizontal and vertical coordinates x and y of the three displacement sensors are fixed values, and the vertical coordinate z is a measured value; establish a posture compensation system including a linear translation stage, a pitch translation stage, and a rotation translation stage, assembling the three displacement sensors into the posture compensation system so that the linear translation stage moves along the z-axis of the posture measurement system;

[0007] Step S200: Set the pitching stage and the rotation stage to zero, and gradually move the linear stage. For each movement, record the measurement values ​​z measured by the three displacement sensors. 11 、z 12 and z 13 and the measured value Z measured by the linear translation stage; based on the measured value z recorded during each movement 11 、z 12 and z 13 and Z, respectively perform first-order fitting on the measurement values ​​of the three displacement sensors to obtain the measurement fitting curves corresponding to the three displacement sensors;

[0008] Step S300: Set the rotation stage and the linear stage to zero, rotate the pitch stage gradually, and record the measurement values ​​z measured by the three displacement sensors for each rotation. 21 、z 22 and z 23And the pitch angle θ1 measured by the pitch displacement stage; using the corresponding measurement fitting curve, the measured value z 21 、z 22 and z 23 Perform error compensation; according to the measured value z after error compensation 21 、z 22 and z 23 , calculate the pitch angle θ2; based on the pitch angle θ1 recorded during each movement and the calculated pitch angle θ2, perform a first-order fitting on the pitch angle to obtain a pitch angle fitting curve;

[0009] Step S400: Set the pitching stage and the linear stage to zero, gradually rotate the rotation stage, and record the measurement values ​​z measured by the three displacement sensors for each rotation. 31 、z 32 and z 33 and the yaw angle measured by the rotation stage Use the corresponding measurement fitting curve to measure the measured value z 31 、z 32 and z 33 Perform error compensation; according to the measured value z after error compensation 31 、z 32 and z 33 , calculate the yaw angle Based on the yaw angle recorded during each movement and the calculated yaw angle Performing a first-order fitting on the yaw angle to obtain a yaw angle fitting curve;

[0010] Step S500: The three displacement sensors respectively measure the measurement values ​​z in the posture measurement system. 41 、z 42 and z 43 Then, firstly, the measured value z is fitted according to the corresponding measurement curve. 41 、z 42 and z 43 Perform error compensation, and then use the measured value z after error compensation 41 、z 42 and z 43 , calculate the pitch angle θ3 and yaw angle The pitch angle fitting curve is used to compensate the pitch angle θ3; the yaw angle fitting curve is used to compensate the yaw angle Perform error compensation.

[0011] In an optional implementation, the step S200 performs first-order fitting on the measurement values ​​of the three displacement sensors respectively in the following manner: for the measurement value z measured by each displacement sensor 1j, j is the number of the displacement sensor and its value is 1, 2 and 3, the measurement value Z measured by the linear displacement stage is the horizontal coordinate of the measurement point on the measurement fitting curve, and the measurement value z measured by the displacement sensor is 1j The vertical coordinate of the corresponding measurement point on the measurement fitting curve is obtained, and the corresponding number of discrete measurement points is obtained; the first-order fitting is performed on the discrete measurement points to obtain the measurement fitting curve of the displacement sensor: 1j =Z*k 1j +b 1j , where k 1j is the slope of the corresponding measurement point in the measurement fitting curve, b 1j is the intercept of the corresponding measurement point in the measurement fitting curve;

[0012] The step S300 is performed on the measured value z in the following manner: 21 、z 22 and z 23 Error compensation: for the measured value z 2j , the measured value after error compensation is: 1 / k 1j *(z 2j -b 1j ), where k 1j The vertical coordinate is z in the corresponding measurement error curve 2j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 2j The intercept of the measurement point;

[0013] The step S400 is performed on the measured value z in the following manner: 31 、z 32 and z 33 Error compensation: for the measured value z 3j , the measured value after error compensation is: 1 / k 1j *(z 3j -b 1j ), where k 1j The vertical coordinate is z in the corresponding measurement error curve 3j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 3j The intercept of the measurement point;

[0014] The step S500 is performed on the measured value z in the following manner: 41 、z 42 and z 43 Error compensation: for the measured value z 4j , the measured value after error compensation is: 1 / k 1j *(z 4j -b 1j ), where k1j The vertical coordinate is z in the corresponding measurement error curve 4j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 4j The intercept of the measurement point.

[0015] In another optional implementation, in the posture measurement system and the posture compensation system, the horizontal and vertical coordinates x and y of the three displacement sensors remain unchanged; in the step S300, the measured value z after error compensation is 21 、z 22 and z 23 , calculate the pitch angle θ2 by following the steps below:

[0016] Step S310: Assume that the coordinates of the three displacement sensors are (x1, y1, z 21 )、(x2,y2,z 22 ) and (x3,y3,z 23 ), calculate the normal vector of the plane to be measured:

[0017]

[0018] in,

[0019] a=(y2-y1)*(z 23 -z 21 )-(y3-y1)*(z 22 -z 21 )

[0020] b=(z 22 -z 21 )*(x3-x1)-(z 23 -z 21 )*(x2-x1);

[0021] c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1)

[0022] Step S320: Calculate the pitch angle θ2 according to the following formula:

[0023] In step S500, the error-compensated measured value z 41 、z 42 and z 43 , calculate the pitch angle θ3 by following the steps below:

[0024] Step S510: Assume that the coordinates of the three displacement sensors are (x1, y1, z 41 )、(x2,y2,z 42 ) and (x3,y3,z43 ), calculate the normal vector of the plane to be measured:

[0025]

[0026] in,

[0027] a=(y2-y1)*(z 43 -z 41 )-(y3-y1)*(z 42 -z 41 )

[0028] b=(z 42 -z 41 )*(x3-x1)-(z 43 -z 41 )*(x2-x1);

[0029] c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1)

[0030] Step S520: Calculate the pitch angle θ3 according to the following formula:

[0031] In another optional implementation, in the posture measurement system and the posture compensation system, the horizontal and vertical coordinates x and y of the three displacement sensors remain unchanged; in the step S400, the measured value z after error compensation is 31 、z 32 and z 33 , follow the steps below to calculate the yaw angle

[0032] Step S410: Assume that the coordinates of the three displacement sensors are (x1, y1, z 11 )、(x2,y2,z 12 ) and (x3,y3,z 33 ), calculate the normal vector of the plane to be measured:

[0033]

[0034] in,

[0035] a=(y2-y1)*(z 33 -z 31 )-(y3-y1)*(z 32 -z 31 )

[0036] b=(z 32 -z 31 )*(x3-x1)-(z 33 -z 31)*(x2-x1);

[0037] c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1)

[0038] Step S420: Calculate the yaw angle according to the following formula:

[0039] In step S500, the error-compensated measured value z 41 、z 42 and z 43 , follow the steps below to calculate the yaw angle

[0040] Step S530: Assume that the coordinates of the three displacement sensors are (x1, y1, z 41 )、(x2,y2,z 42 ) and (x3,y3,z 43 ), calculate the normal vector of the plane to be measured:

[0041]

[0042] in,

[0043] a=(y2-y1)*(z 43 -z 41 )-(y3-y1)*(z 42 -z 41 )

[0044] b=(z 42 -z 41 )*(x3-x1)-(z 43 -z 41 )*(x2-x1);

[0045] c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1)

[0046] Step S540: Calculate the yaw angle according to the following formula:

[0047] In another optional implementation, step S300 performs a first-order fitting on the pitch angle in the following manner:

[0048] The pitch angle θ1 measured by the pitch stage is used as the abscissa of the measurement point on the pitch angle fitting curve, and the pitch angle θ2 calculated at the corresponding time is used as the ordinate of the corresponding measurement point on the pitch angle fitting curve, thereby obtaining a corresponding number of discrete measurement points. A first-order fitting is performed on the discrete measurement points to obtain the pitch angle fitting curve: θ2 = θ1·k2 + b2, where k2 is the slope of the corresponding measurement point in the pitch angle fitting curve, and b2 is the intercept of the corresponding measurement point in the pitch angle fitting curve.

[0049] The step S500 performs error compensation on the pitch angle θ3 according to the following formula:

[0050] θ is the pitch angle after θ3 error compensation, k2 is the slope of the measurement point with ordinate θ3 in the pitch angle fitting curve, and b2 is the intercept of the measurement point with ordinate θ3 in the pitch angle fitting curve.

[0051] In another optional implementation, step S400 performs a first-order fitting on the yaw angle in the following manner:

[0052] The yaw angle measured by the rotation stage is the horizontal coordinate of the measurement point on the yaw angle fitting curve, corresponding to the calculated yaw angle is the ordinate of the corresponding measurement point on the yaw angle fitting curve, and the corresponding number of discrete measurement points are obtained; a first-order fitting is performed on the discrete measurement points to obtain the yaw angle fitting curve: Where k3 is the slope of the corresponding measurement point in the yaw angle fitting curve, and b3 is the intercept of the corresponding measurement point in the yaw angle fitting curve;

[0053] The step S500 calculates the yaw angle according to the following formula: To perform error compensation: for The yaw angle after error compensation, k3 is the ordinate of the yaw angle fitting curve The slope of the measurement point, b2 is the ordinate of the yaw angle fitting curve The intercept of the measurement point.

[0054] In another optional implementation, the pitch angle is the angle formed between the plane to be measured rotating around the x-axis and the xoz plane, and the pitch translation stage rotates around the x-axis; the yaw angle is the angle formed between the plane to be measured rotating around the y-axis and the xoy plane, and the rotation translation stage rotates around the y-axis; the displacement sensor is a contact displacement sensor, which is fixed on the plane to be measured.

[0055] In another optional implementation, the step S200 further includes: for each displacement sensor measured value z 1j , the values ​​of j are 1, 2 and 3, and the measurement error of the displacement sensor is calculated as: Δz = z ij -Z;

[0056] The step S300 further includes: calculating the measurement error of the pitch angle: Δθ=θ2-θ1;

[0057] The step S400 further includes calculating the measurement error of the yaw angle:

[0058] In another optional implementation, the least squares method is used to perform first-order fitting.

[0059] In another optional implementation, the linear translation stage moves step by step at equal intervals; the pitch translation stage and the rotation translation stage rotate step by step at equal angles according to corresponding angles, respectively.

[0060] The beneficial effects of the present invention are:

[0061] The present invention uses three displacement sensors to build a surface posture measurement system, which can measure the pitch angle and yaw angle of the plane to be measured, expanding from traditional point measurement to surface measurement; the present invention has significant advantages such as simple structure, measurement accuracy, high reliability, and low cost, and is suitable for surface measurement in extreme and complex environments; the present invention can compensate for signal detection and processing errors and assembly errors, improve the full-range measurement accuracy of the posture measurement system, and realize high-precision posture measurement; it can be seen that the present invention is a high-precision, low-cost, and high-reliability surface posture measurement method, and can realize full-range error compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a flow chart of an embodiment of the high-precision posture measurement error compensation method of the present invention;

[0063] Figure 2 1 is a schematic structural diagram of an embodiment of the posture measurement system of the present invention;

[0064] Figure 3 It is a schematic structural diagram of an embodiment of the posture compensation system of the present invention. DETAILED DESCRIPTION

[0065] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention and to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0066] In the description of the present invention, unless otherwise specified and limited, it should be noted that the term "connection" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two elements. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meaning of the above terms can be understood according to the specific circumstances.

[0067] See also Figure 1 , is a flow chart of an embodiment of the high-precision posture measurement error compensation method of the present invention. Figure 2 and Figure 3 As shown, the high-precision posture measurement error compensation method may include the following steps:

[0068] Step S100: Establish a posture measurement system including three displacement sensors, where the horizontal and vertical coordinates x and y of the three displacement sensors are fixed values, and the vertical coordinate z is a measured value; establish a posture compensation system including a linear translation stage, a pitch translation stage, and a rotation translation stage, and assemble the three displacement sensors into the posture compensation system so that the linear translation stage moves along the z-axis of the posture measurement system.

[0069] In this embodiment, the three displacement sensors may be contact displacement sensors, which are fixed on the plane to be measured, and the positional relationship between the three displacement sensors is fixed. In the posture measurement system and posture compensation system, the horizontal and vertical coordinates x and y of the three displacement sensors may remain unchanged.

[0070] Step S200: Set the pitching stage and the rotation stage to zero, and gradually move the linear stage. For each movement, record the measurement values ​​z measured by the three displacement sensors. 11 、z 12 and z 13 and the measured value Z measured by the linear translation stage; based on the measured value z recorded during each movement 11 、z 12 and z 13 and Z, perform first-order fitting on the measurement values ​​of the three displacement sensors respectively to obtain the measurement fitting curves corresponding to the three displacement sensors.

[0071] In this embodiment, the linear translation stage can be moved step by step at equal intervals. Step S200 can perform first-order fitting on the measured values ​​of the three displacement sensors in the following manner: for the measured value z measured by each displacement sensor, 1j , j is the number of the displacement sensor and its value is 1, 2 and 3, the measurement value Z measured by the linear displacement stage is the horizontal coordinate of the measurement point on the measurement fitting curve, and the measurement value z measured by the displacement sensor is 1jThe vertical coordinate of the corresponding measurement point on the measurement fitting curve is obtained, and the corresponding number of discrete measurement points is obtained; the first-order fitting is performed on the discrete measurement points to obtain the measurement fitting curve of the displacement sensor: 1j =Z*k 1j +b 1j , where k 1j is the slope of the corresponding measurement point in the measurement fitting curve, b 1j is the intercept of the corresponding measurement point in the measurement fitting curve. The least square method can be used for first-order fitting.

[0072] Step S300: Set the rotation stage and the linear stage to zero, rotate the pitch stage gradually, and record the measurement values ​​z measured by the three displacement sensors for each rotation. 21 、z 22 and z 23 And the pitch angle θ1 measured by the pitch displacement stage; using the corresponding measurement fitting curve, the measured value z 21 、z 22 and z 23 Perform error compensation; according to the measured value z after error compensation 21 、z 22 and z 23 , calculate the pitch angle θ2; based on the pitch angle θ1 recorded during each movement and the calculated pitch angle θ2, perform a first-order fitting on the pitch angle to obtain a pitch angle fitting curve.

[0073] In this embodiment, the pitching stage can be rotated step by step according to the corresponding angles, and the rotation direction can be the same as the pitch direction of the plane to be measured, that is, rotating around the x-axis. The step S300 can be performed in the following manner to measure the measured value z 21 、z 22 and z 23 To perform error compensation:

[0074] For the measured value z 2j , the measured value after error compensation is: 1 / k 1j *(z 2j -b 1j ), k 1j The vertical coordinate is z in the corresponding measurement error curve 2j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 2j The intercept of the measurement point, j takes the values ​​of 1, 2 and 3.

[0075] In step S300, the error-compensated measured value z 21 、z 22 and z 23, the pitch angle θ2 can be calculated by following the steps below:

[0076] Step S310: Assume that the coordinates of the three displacement sensors are (x1, y1, z 21 )、(x2,y2,z 22 ) and (x3,y3,z 23 ), calculate the normal vector of the plane to be measured:

[0077]

[0078] in,

[0079] a=(y2-y1)*(z 23 -z 21 )-(y3-y1)*(z 22 -z 21 )

[0080] b=(z 22 -z 21 )*(x3-x1)-(z 23 -z 21 )*(x2-x1);

[0081] c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1)

[0082] Step S320: Calculate the pitch angle θ2 according to the following formula:

[0083] The arctan(x,y) function calculates the angle between the vector from the origin to the point (x,y) and the x-axis. Compared with the arctan(x / y) function, it can correctly handle angles in different quadrants and consider the signs of x and y, thereby returning an angle in the range [-π, π].

[0084] In step S300, the first-order fitting of the pitch angle can be performed in the following manner:

[0085] The pitch angle θ1 measured by the pitch stage is used as the abscissa of the measurement point on the pitch angle fitting curve, and the corresponding pitch angle θ2 calculated is used as the ordinate of the corresponding measurement point on the pitch angle fitting curve, thereby obtaining a corresponding number of discrete measurement points. A first-order fitting is performed on the discrete measurement points to obtain the pitch angle fitting curve: θ2 = θ1·k2 + b2, where k2 is the slope of the corresponding measurement point on the pitch angle fitting curve, and b2 is the intercept of the corresponding measurement point on the pitch angle fitting curve. The first-order fitting can be performed using the least squares method.

[0086] Step S400: Set the pitching stage and the linear stage to zero, gradually rotate the rotation stage, and record the measurement values ​​z measured by the three displacement sensors for each rotation. 31 、z 32 and z 33 and the yaw angle measured by the rotation stage Use the corresponding measurement fitting curve to measure the measured value z 31 、z 32 and z 33 Perform error compensation; according to the measured value z after error compensation 31 、z 32 and z 33 , calculate the yaw angle Based on the yaw angle recorded during each movement and the calculated yaw angle Perform a first-order fitting on the yaw angle to obtain a yaw angle fitting curve.

[0087] In this embodiment, the rotation stage can be rotated step by step according to the corresponding angle, and the rotation direction can be the same as the rolling direction of the plane to be measured, that is, rotating around the y-axis. The step S400 can be performed in the following manner to measure the value z 31 、z 32 and z 33 Error compensation: for the measured value z 3j , the measured value after error compensation is: 1 / k 1j *(z 3j -b 1j ), where k 1j The vertical coordinate is z in the corresponding measurement error curve 3j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 3j The intercept of the measurement point.

[0088] In step S400, the measured value z after error compensation is 31 、z 32 and z 33 , follow the steps below to calculate the yaw angle

[0089] Step S410: Assume that the coordinates of the three displacement sensors are (x1, y1, z 31 )、(x2,y2,z 32 ) and (x3,y3,z 33 ), calculate the normal vector of the plane to be measured:

[0090]

[0091] in,

[0092] a=(y2-y1)*(z 33 -z 31 )-(y3-y1)*(z 32 -z 31 )

[0093] b=(z 32 -z 31 )*(x3-x1)-(z 33 -z 31 )*(x2-x1);

[0094] c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1)

[0095] Step S420: Calculate the yaw angle according to the following formula:

[0096]

[0097] In step S400, the first-order fitting of the yaw angle can be performed in the following manner:

[0098] The yaw angle measured by the rotation stage is the horizontal coordinate of the measurement point on the yaw angle fitting curve, corresponding to the calculated yaw angle is the ordinate of the corresponding measurement point on the yaw angle fitting curve, and the corresponding number of discrete measurement points are obtained; a first-order fitting is performed on the discrete measurement points to obtain the yaw angle fitting curve: Wherein, k3 is the slope of the corresponding measurement point in the yaw angle fitting curve, and b3 is the intercept of the corresponding measurement point in the yaw angle fitting curve. A least squares method can be used for first-order fitting.

[0099] Step S500: The three displacement sensors respectively measure the measurement values ​​z in the posture measurement system. 41 、z 42 and z 43 Then, firstly, the measured value z is fitted according to the corresponding measurement curve. 41 、z 42 and z 43 Perform error compensation, and then use the measured value z after error compensation 41 、z 42 and z 43 , calculate the pitch angle θ3 and yaw angle The pitch angle fitting curve is used to compensate the pitch angle θ3; the yaw angle fitting curve is used to compensate the yaw angle Perform error compensation.

[0100] In this embodiment, the step S500 can be performed in the following manner: 41 、z 42 and z 43 Error compensation: for the measured value z 4j , the measured value after error compensation is: 1 / k 1j *(z 4j -b 1j ), where k 1j The vertical coordinate is z in the corresponding measurement error curve 4j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 4j The intercept of the measurement point.

[0101] In step S500, the error-compensated measured value z 41 、z 42 and z 43 , the pitch angle θ3 can be calculated by following the steps below:

[0102] Step S510: Assume that the coordinates of the three displacement sensors are (x1, y1, z 41 )、(x2,y2,z 42 ) and (x3,y3,z 43 ), calculate the normal vector of the plane to be measured:

[0103]

[0104] in,

[0105] a=(y2-y1)*(z 43 -z 41 )-(y3-y1)*(z 42 -z 41 )

[0106] b=(z 42 -z 41 )*(x3-x1)-(z 43 -z 41 )*(x2-x1);

[0107] c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1)

[0108] Step S520: Calculate the pitch angle θ3 according to the following formula:

[0109]

[0110] In step S500, the error-compensated measured value z 41 、z42 and z 43 , the yaw angle can be calculated by following the steps below

[0111] Step S530: Assume that the coordinates of the three displacement sensors are (x1, y1, z 41 )、(x2,y2,z 42 ) and (x3,y3,z 43 ), calculate the normal vector of the plane to be measured:

[0112]

[0113] in,

[0114] a=(y2-y1)*(z 43 -z 41 )-(y3-y1)*(z 42 -z 41 )

[0115] b=(z 42 -z 41 )*(x3-x1)-(z 43 -z 41 )*(x2-x1);

[0116] c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1)

[0117] Step S540: Calculate the yaw angle according to the following formula:

[0118]

[0119] In step S500, the pitch angle Δ3 may be compensated for an error according to the following formula:

[0120] θ is the pitch angle after Δ3 error compensation, k2 is the slope of the measurement point with ordinate Δ3 in the pitch angle fitting curve, and b2 is the intercept of the measurement point with ordinate θ3 in the pitch angle fitting curve.

[0121] The step S500 can be performed according to the following formula for the yaw angle To perform error compensation: for The yaw angle after error compensation, k3 is the ordinate of the yaw angle fitting curve The slope of the measurement point, b2 is the ordinate of the yaw angle fitting curve The intercept of the measurement point.

[0122] In addition, in this embodiment, the pitch angle can be the angle formed by the rotation of the plane to be measured around the x-axis and the xoz plane; the yaw angle can be the angle formed by the rotation of the plane to be measured around the y-axis and the xoy plane. The step S200 further includes: for each displacement sensor measured value z 1j , the values ​​of j are 1, 2 and 3, and the measurement error of the displacement sensor is calculated as: Δz = z ij -Z; the step S300 further comprises: calculating the measurement error of the pitch angle: Δθ = θ2-θ1; the step S400 further comprises: calculating the measurement error of the yaw angle: The present invention calculates the measurement errors of the displacement sensor, pitch angle and yaw angle, which can reflect the error size more intuitively and facilitate user debugging.

[0123] During the experiment, a posture measurement system was built using three displacement sensors. Before compensation, the displacement measurement accuracy of the three displacement sensors was 10um, and the posture measurement accuracy was 0.05°. After compensation, the measurement accuracy of the three displacement sensors was 5um, and the posture measurement accuracy was 0.02°. It can be seen that the measurement accuracy of the present invention has been improved.

[0124] It can be seen from the above embodiments that the present invention uses three displacement sensors to build a surface posture measurement system, which can measure the pitch angle and yaw angle of the plane to be measured, and expands from traditional point measurement to surface measurement; the present invention has significant advantages such as simple structure, measurement accuracy, high reliability, and low cost, and is suitable for surface measurement in extreme and complex environments; the present invention compensates for signal detection and processing errors and assembly errors, which can improve the full-range measurement accuracy of the posture measurement system and realize high-precision posture measurement; it can be seen that the present invention is a high-precision, low-cost, and high-reliability surface posture measurement method, and can realize full-range error compensation.

[0125] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0126] It will be appreciated that the present invention is not limited to the precise construction that has been described above and shown in the accompanying drawings, and that various modifications and variations can be made without departing from its scope, which is governed solely by the appended claims.

Claims

1. A high-precision posture measurement error compensation method, characterized in that: include: Step S100: Establish a posture measurement system including three displacement sensors, wherein the horizontal and vertical coordinates x and y of the three displacement sensors are fixed values, and the vertical coordinate z is a measured value; establish a posture compensation system including a linear translation stage, a pitch translation stage, and a rotation translation stage, assembling the three displacement sensors into the posture compensation system so that the linear translation stage moves along the z-axis of the posture measurement system; Step S200: Set the pitching stage and the rotation stage to zero, and gradually move the linear stage. For each movement, record the measurement values ​​z measured by the three displacement sensors. 11 、z 12 and z 13 and the measured value Z measured by the linear translation stage; based on the measured value z recorded during each movement 11 、z 12 and z 13 and Z, respectively perform first-order fitting on the measurement values ​​of the three displacement sensors to obtain the measurement fitting curves corresponding to the three displacement sensors; Step S300: Set the rotation stage and the linear stage to zero, rotate the pitch stage gradually, and record the measurement values ​​z measured by the three displacement sensors for each rotation. 21 、z 22 and z 23 And the pitch angle θ1 measured by the pitch displacement stage; using the corresponding measurement fitting curve, the measured value z 21 、z 22 and z 23 Perform error compensation; according to the measured value z after error compensation 21 、z 22 and z 23 , calculate the pitch angle θ2; based on the pitch angle θ1 recorded during each movement and the calculated pitch angle θ2, perform a first-order fitting on the pitch angle to obtain a pitch angle fitting curve; Step S400: Set the pitching stage and the linear stage to zero, gradually rotate the rotation stage, and record the measurement values ​​z measured by the three displacement sensors for each rotation. 31 、z 32 and z 33 and the yaw angle measured by the rotation stage Use the corresponding measurement fitting curve to measure the measured value z 31 、z 32 and z 33 Perform error compensation; according to the measured value z after error compensation 31 、z 32 and z 33 , calculate the yaw angle Based on the yaw angle recorded during each movement and the calculated yaw angle Performing a first-order fitting on the yaw angle to obtain a yaw angle fitting curve; Step S500: The three displacement sensors respectively measure the measurement values ​​z in the posture measurement system. 41 、z 42 and z 43 Then, firstly, the measured value z is fitted according to the corresponding measurement curve. 41 、z 42 and z 43 Perform error compensation, and then use the measured value z after error compensation 41 、z 42 and z 43 , calculate the pitch angle θ3 and yaw angle The pitch angle fitting curve is used to compensate the pitch angle θ3; the yaw angle fitting curve is used to compensate the yaw angle Perform error compensation.

2. The high-precision posture measurement error compensation method according to claim 1, characterized in that: The step S200 performs first-order fitting on the measured values ​​of the three displacement sensors in the following manner: for the measured value z measured by each displacement sensor, 1j , j is the number of the displacement sensor and its value is 1, 2 and 3, the measurement value Z measured by the linear displacement stage is the horizontal coordinate of the measurement point on the measurement fitting curve, and the measurement value z measured by the displacement sensor is 1j The vertical coordinate of the corresponding measurement point on the measurement fitting curve is obtained, and the corresponding number of discrete measurement points is obtained; the first-order fitting is performed on the discrete measurement points to obtain the measurement fitting curve of the displacement sensor: 1j =Z*k 1j +b 1j , where k 1j is the slope of the corresponding measurement point in the measurement fitting curve, b 1j is the intercept of the corresponding measurement point in the measurement fitting curve; The step S300 is performed on the measured value z in the following manner: 21 、z 22 and z 23 Error compensation: for the measured value z 2j , the measured value after error compensation is: 1 / k 1j *(z 2j -b 1j ), where k 1j The vertical coordinate is z in the corresponding measurement error curve 2j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 2j The intercept of the measurement point; The step S400 is performed on the measured value z in the following manner: 31 、z 32 and z 33 Error compensation: for the measured value z 3j , the measured value after error compensation is: 1 / k 1j *(z 3j -b 1j ), where k 1j The vertical coordinate is z in the corresponding measurement error curve 3j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 3j The intercept of the measurement point; The step S500 is performed on the measured value z in the following manner: 41 、z 42 and z 43 Error compensation: for the measured value z 4j , the measured value after error compensation is: 1 / k 1j *(z 4j -b 1j ), where k 1j The vertical coordinate is z in the corresponding measurement error curve 4j The slope of the measurement point, b 1j The vertical coordinate is z in the corresponding measurement error curve 4j The intercept of the measurement point.

3. The high-precision posture measurement error compensation method according to claim 1, characterized in that: In the posture measurement system and posture compensation system, the horizontal and vertical coordinates x and y of the three displacement sensors remain unchanged; in the step S300, the measured value z after error compensation is 21 、z 22 and z 23 , calculate the pitch angle θ2 by following the steps below: Step S310: Assume that the coordinates of the three displacement sensors are (x1, y1, z 21 )、(x2,y2,z 22 ) and (x3,y3,z 23 ), calculate the normal vector of the plane to be measured: in, Step S320: Calculate the pitch angle θ2 according to the following formula: In step S500, the error-compensated measured value z 41 、z 42 and z 43 , calculate the pitch angle θ3 by following the steps below: Step S510: Assume that the coordinates of the three displacement sensors are (x1, y1, z 41 )、(x2,y2,z 42 ) and (x3,y3,z 43 ), calculate the normal vector of the plane to be measured: in, Step S520: Calculate the pitch angle θ3 according to the following formula:

4. The high-precision posture measurement error compensation method according to claim 1, characterized in that: In the posture measurement system and posture compensation system, the horizontal and vertical coordinates x and y of the three displacement sensors remain unchanged; in the step S400, the measured value z after error compensation is 31 、z 32 and z 33 , follow the steps below to calculate the yaw angle Step S410: Assume that the coordinates of the three displacement sensors are (x1, y1, z 31 )、(x2,y2,z 32 ) and (x3,y3,z 33 ), calculate the normal vector of the plane to be measured: in, Step S420: Calculate the yaw angle according to the following formula: In step S500, the error-compensated measured value z 41 、z 42 and z 43 , follow the steps below to calculate the yaw angle Step S530: Assume that the coordinates of the three displacement sensors are (x1, y1, z 41 )、(x2,y2,z 42 ) and (x3,y3,z 43 ), calculate the normal vector of the plane to be measured: in, Step S540: Calculate the yaw angle according to the following formula:

5. The high-precision posture measurement error compensation method according to claim 1, characterized in that: The step S300 performs a first-order fitting on the pitch angle in the following manner: The pitch angle θ1 measured by the pitch stage is used as the abscissa of the measurement point on the pitch angle fitting curve, and the pitch angle θ2 calculated at the corresponding time is used as the ordinate of the corresponding measurement point on the pitch angle fitting curve, thereby obtaining a corresponding number of discrete measurement points. A first-order fitting is performed on the discrete measurement points to obtain the pitch angle fitting curve: θ2 = θ1·k2 + b2, where k2 is the slope of the corresponding measurement point in the pitch angle fitting curve, and b2 is the intercept of the corresponding measurement point in the pitch angle fitting curve. The step S500 performs error compensation on the pitch angle θ3 according to the following formula: θ is the pitch angle after θ3 error compensation, k2 is the slope of the measurement point with ordinate θ3 in the pitch angle fitting curve, and b2 is the intercept of the measurement point with ordinate θ3 in the pitch angle fitting curve.

6. The high-precision posture measurement error compensation method according to claim 1, characterized in that: The step S400 performs a first-order fitting on the yaw angle in the following manner: The yaw angle measured by the rotation stage is the horizontal coordinate of the measurement point on the yaw angle fitting curve, corresponding to the calculated yaw angle is the ordinate of the corresponding measurement point on the yaw angle fitting curve, and the corresponding number of discrete measurement points are obtained; a first-order fitting is performed on the discrete measurement points to obtain the yaw angle fitting curve: Where k3 is the slope of the corresponding measurement point in the yaw angle fitting curve, and b3 is the intercept of the corresponding measurement point in the yaw angle fitting curve; The step S500 calculates the yaw angle according to the following formula: To perform error compensation: for The yaw angle after error compensation, k3 is the ordinate of the yaw angle fitting curve The slope of the measurement point, b2 is the ordinate of the yaw angle fitting curve The intercept of the measurement point.

7. The high-precision posture measurement error compensation method according to claim 1, characterized in that: The pitch angle is the angle formed between the plane to be measured rotating around the x-axis and the xoz plane, and the pitch translation stage rotates around the x-axis; the yaw angle is the angle formed between the plane to be measured rotating around the y-axis and the xoy plane, and the rotation translation stage rotates around the y-axis.

8. The high-precision posture measurement error compensation method according to claim 1, characterized in that: The step S200 further includes: for each displacement sensor measured value z 1j , the values ​​of j are 1, 2 and 3, and the measurement error of the displacement sensor is calculated as: Δz = z ij -Z; The step S300 further includes: calculating the measurement error of the pitch angle: Δθ=θ2-θ1; The step S400 further includes calculating the measurement error of the yaw angle:

9. The high-precision posture measurement error compensation method according to claim 1, characterized in that: The least squares method was used for first-order fitting.

10. The high-precision posture measurement error compensation method according to claim 1, characterized in that: The linear displacement stage moves step by step at equal intervals; the pitch displacement stage and the rotation displacement stage rotate step by step at corresponding angles; the displacement sensor is a contact displacement sensor, which is fixed on the plane to be measured.

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