High-precision pose measurement error compensation method

Abstract

The invention provides a high-precision pose measurement error compensation method, which comprises the following steps of: establishing a pose measurement system and a pose compensation system, assembling three displacement sensors in the pose measurement system into the pose compensation system, controlling a linear displacement table in the pose compensation system to move step by step, and obtaining a measurement fitting curve of the three displacement sensors, respectively controlling a pitching displacement table and a rotary displacement table in the pose compensation system to rotate step by step, and determining a pitching angle fitting curve and a yaw angle fitting curve according to the measurement fitting curve, z-axis measurement values measured by the three displacement sensors, a pitching angle measured by the pitching displacement table and a yaw angle measured by the rotary displacement table; the pitch angle fitting curve and the yaw angle fitting curve are used for conducting error compensation on the pitch angle and the yaw angle determined in the pose measurement system respectively. According to the invention, signal detection and processing errors and assembly errors can be compensated, the full-scale measurement precision of the pose measurement system is improved, and high-precision pose measurement is realized.

Description

Technical Field

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

[0002] The demand for posture and interoperability detection in application fields such as major strategic equipment and mechanical precision manufacturing is constantly increasing. Stable control of the posture and interoperability of key components of high-precision and major strategic equipment within a reasonable range is crucial to improving product performance and safety.

[0003] Among them, the contact displacement measurement system has significant advantages such as simple structure, high measurement accuracy and reliability. However, the measurement results of the existing posture measurement system still have 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, establishing 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; establishing 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: reset the pitching stage and the rotation stage to zero, gradually move the linear stage, and record the measured values ​​z respectively measured by the three displacement sensors for each movement. 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 measured 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, gradually rotate the pitch stage, and record the measured values ​​z respectively measured by the three displacement sensors for each rotation. 21 、z 22 and z 23And the pitch angle θ measured by the pitch stage 1 ; Use the corresponding measurement fitting curve to measure 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 θ 2 Based on the pitch angle θ recorded during each movement 1 And the calculated pitch angle θ 2 , 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 respectively measured by the three displacement sensors for each rotation. 31 、z 32 and z 33 And the yaw angle measured by the rotation stage The corresponding measurement fitting curve is used 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 After that, firstly, the measured value z is respectively calculated according to the corresponding measurement fitting 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 θ 3 and yaw angle The pitch angle fitting curve is used to fit the pitch angle θ 3 Perform error compensation; use the yaw angle fitting curve to Perform error compensation.

[0011] In an optional implementation, the step S200 performs first-order fitting on the measured values ​​of the three displacement sensors respectively in the following manner: for the measured value z measured by each displacement sensor 1j , j is the serial number of the displacement sensor and its value is 1, 2 and 3. The measured value Z measured by the linear displacement stage is the abscissa of the measuring point on the measurement fitting curve. The measured value z of the displacement sensor corresponding to the time is 1j is the ordinate of the corresponding measurement point on the measurement 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 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 performs the following operations on the measured value z: 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 performs the following operations on the measured 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;

[0014] The step S500 performs the following operations on the measured value z: 41 、z 42 and z 43 Error compensation: for the measured value z4j , 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.

[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 θ by following the steps below 2 :

[0016] Step S310: Assume that the coordinates of the three displacement sensors are (x 1 ,y 1 , z 21 )、(x 2 ,y 2 , z 22 ) and (x 3 ,y 3 , z 23 ), calculate the normal vector of the plane to be measured:

[0017]

[0018] in,

[0019]

[0020] Step S320: Calculate the pitch angle θ according to the following formula: 2 :

[0021] In step S500, the error-compensated measured value z 41 、z 42 and z 43 , calculate the pitch angle θ by following the steps below 3 :

[0022] Step S510: Assume that the coordinates of the three displacement sensors are (x 1 ,y 1 , z 41 )、(x 2 ,y 2 , z 42 ) and (x 3,y 3 , z 43 ), calculate the normal vector of the plane to be measured:

[0023]

[0024] in,

[0025]

[0026] Step S520: Calculate the pitch angle θ according to the following formula: 3 :

[0027] 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

[0028] Step S410: Assume that the coordinates of the three displacement sensors are (x 1 ,y 1 , z 31 )、(x 2 ,y 2 , z 32 ) and (x 3 ,y 3 , z 33 ), calculate the normal vector of the plane to be measured:

[0029]

[0030] in,

[0031]

[0032] Step S420: Calculate the yaw angle according to the following formula:

[0033] In step S500, the error-compensated measured value z 4 1. z 42 and z 43 , follow the steps below to calculate the yaw angle

[0034] Step S530: Assume that the coordinates of the three displacement sensors are (x 1 ,y 1 , z 41 )、(x 2 ,y 2, z 42 ) and (x 3 ,y 3 , z 43 ), calculate the normal vector of the plane to be measured:

[0035]

[0036] in,

[0037]

[0038] Step S540: Calculate the yaw angle according to the following formula:

[0039] In another optional implementation, the step S300 performs a first-order fitting on the pitch angle in the following manner:

[0040] The pitch angle θ measured by the pitch stage 1 is the horizontal coordinate of the measured point on the pitch angle fitting curve, corresponding to the calculated pitch angle θ 2 The ordinate of the corresponding measurement point on the pitch angle fitting curve is obtained, and the corresponding number of discrete scattering points is obtained; the first-order fitting is performed on the discrete measurement points to obtain the pitch angle fitting curve: θ 2 =θ 1 ·k 2 +b 2 , where k 2 is the slope of the corresponding measurement point in the pitch angle fitting curve, b 2 is the intercept of the corresponding measurement point in the pitch angle fitting curve;

[0041] In step S500, the pitch angle θ is calculated according to the following formula: 3 To perform error compensation:

[0042] θ is θ 3 Pitch angle after error compensation, k 2 The vertical coordinate of the pitch angle fitting curve is θ 3 The slope of the measurement point, b 2 The vertical coordinate of the pitch angle fitting curve is θ 3 The intercept of the measurement point.

[0043] In another optional implementation, the step S400 performs a first-order fitting on the yaw angle in the following manner:

[0044] 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 scattering points are obtained; a first-order fitting is performed on the discrete measurement points to obtain the yaw angle fitting curve: where k 3 is the slope of the corresponding measurement point in the yaw angle fitting curve, b 3 is the intercept of the corresponding measurement point in the yaw angle fitting curve;

[0045] In step S500, the yaw angle is calculated according to the following formula: To perform error compensation: for Yaw angle after error compensation, k 3 The ordinate of the yaw angle fitting curve is The slope of the measurement point, b 2 The ordinate of the yaw angle fitting curve is The intercept of the measurement point.

[0046] 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 platform 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 platform rotates around the y-axis; the displacement sensor is a contact displacement sensor, which is fixed on the plane to be measured.

[0047] 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: Δz = z ij -Z;

[0048] The step S300 further includes: calculating the measurement error of the pitch angle: Δθ=θ 2 -θ 1 ;

[0049] The step S400 further includes: calculating the measurement error of the yaw angle:

[0050] In another optional implementation, the least square method is used to perform first-order fitting.

[0051] 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 respectively at corresponding angles.

[0052] The beneficial effects of the present invention are:

[0053] The present invention adopts 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 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

[0054] Figure 1 It is a flow chart of an embodiment of the high-precision posture measurement error compensation method of the present invention;

[0055] Figure 2 It is a schematic structural diagram of an embodiment of the posture measurement system of the present invention;

[0056] Figure 3 It is a schematic structural diagram of an embodiment of the posture compensation system of the present invention. DETAILED DESCRIPTION

[0057] 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 understandable, the technical solutions in the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0058] 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 meanings of the above terms can be understood according to specific circumstances.

[0059] 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:

[0060] Step S100, establishing 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; establishing a posture compensation system including a linear translation table, a pitch translation table and a rotation translation table, assembling the three displacement sensors into the posture compensation system, so that the linear translation table moves along the z-axis of the posture measurement system.

[0061] 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 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.

[0062] Step S200: reset the pitching stage and the rotation stage to zero, gradually move the linear stage, and record the measured values ​​z respectively measured by the three displacement sensors for each movement. 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 measured values ​​of the three displacement sensors to obtain the measurement fitting curves corresponding to the three displacement sensors.

[0063] In this embodiment, the linear translation stage can be moved step by step at equal intervals. The 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 serial number of the displacement sensor and its value is 1, 2 and 3. The measured value Z measured by the linear displacement stage is the horizontal coordinate of the measuring point on the measurement fitting curve. The measured value z of the displacement sensor corresponding to the time is 1j is the ordinate of the corresponding measurement point on the measurement 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 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. Among them, the least square method can be used for first-order fitting.

[0064] Step S300: Set the rotation stage and the linear stage to zero, gradually rotate the pitch stage, and record the measured values ​​z respectively measured by the three displacement sensors for each rotation. 21 、z 22 and z 23 And the pitch angle θ measured by the pitch stage 1 ; Use the corresponding measurement fitting curve to measure 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 z23 , calculate the pitch angle θ 2 Based on the pitch angle θ recorded during each movement 1 And the calculated pitch angle θ 2 , perform a first-order fitting on the pitch angle to obtain the pitch angle fitting curve.

[0065] In this embodiment, the pitch translation stage can be rotated step by step at the corresponding angles and equal angles, and the rotation direction can be the same as the pitch direction of the plane to be measured, that is, rotation around the x-axis. The step S300 can be performed in the following manners to measure the measured value z 21 、z 22 and z 23 To perform error compensation:

[0066] 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, the values ​​of j are 1, 2 and 3.

[0067] In step S300, the error-compensated measured value z 21 、z 22 and z 23 , the pitch angle θ can be calculated by following the steps below 2 :

[0068] Step S310: Assume that the coordinates of the three displacement sensors are (x 1 ,y 1 , z 21 )、(x 2 ,y 2 , z 22 ) and (x 3 ,y 3 , z 23 ), calculate the normal vector of the plane to be measured:

[0069]

[0070] in,

[0071]

[0072] Step S320: Calculate the pitch angle θ according to the following formula: 2 :

[0073] The function arctan(x, y) is used to calculate the angle between the vector from the origin to the point (x, y) and the x-axis. Compared with the function arctan(x / y), 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].

[0074] The step S300 may perform a first-order fitting on the pitch angle in the following manner:

[0075] The pitch angle θ measured by the pitch stage 1 is the horizontal coordinate of the measured point on the pitch angle fitting curve, corresponding to the calculated pitch angle θ 2 The ordinate of the corresponding measurement point on the pitch angle fitting curve is obtained, and the corresponding number of discrete scattering points is obtained; the first-order fitting is performed on the discrete measurement points to obtain the pitch angle fitting curve: θ 2 =θ 1 ·k 2 +b 2 , where k 2 is the slope of the corresponding measurement point in the pitch angle fitting curve, b 2 is the intercept of the corresponding measurement point in the pitch angle fitting curve. Among them, the least square method can be used for first-order fitting.

[0076] Step S400: set the pitching stage and the linear stage to zero, gradually rotate the rotation stage, and record the measurement values ​​z respectively measured by the three displacement sensors for each rotation. 31 、z 32 and z 33 And the yaw angle measured by the rotation stage The corresponding measurement fitting curve is used 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 A first-order fitting is performed on the yaw angle to obtain a yaw angle fitting curve.

[0077] In this embodiment, the rotation stage can be rotated step by step at the corresponding angles and equal angles, 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 manners to measure the measured value z 31 、z 32 and z 33Error 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.

[0078] In step S400, the error-compensated measured value z 31 、z 32 and z 33 , follow the steps below to calculate the yaw angle

[0079] Step S410: Assume that the coordinates of the three displacement sensors are (x 1 ,y 1 , z 31 )、(x 2 ,y 2 , z 32 ) and (x 3 ,y 3 , z 33 ), calculate the normal vector of the plane to be measured:

[0080]

[0081] in,

[0082]

[0083] Step S420: Calculate the yaw angle according to the following formula:

[0084]

[0085] The step S400 may perform a first-order fitting on the yaw angle in the following manner:

[0086] 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 scattering points are obtained; a first-order fitting is performed on the discrete measurement points to obtain the yaw angle fitting curve: where k 3 is the slope of the corresponding measurement point in the yaw angle fitting curve, b 3is the intercept of the corresponding measurement point in the yaw angle fitting curve. Among them, the least square method can be used for first-order fitting.

[0087] Step S500: The three displacement sensors respectively measure the measurement values ​​z in the posture measurement system. 41 、z 42 and z 43 After that, firstly, the measured value z is respectively calculated according to the corresponding measurement fitting 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 θ 3 and yaw angle The pitch angle fitting curve is used to fit the pitch angle θ 3 Perform error compensation; use the yaw angle fitting curve to Perform error compensation.

[0088] In this embodiment, the step S500 can be performed on the measured value z in the following manners: 4 1. 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.

[0089] In step S500, the error-compensated measured value z 41 、z 42 and z 43 , the pitch angle θ can be calculated by following the steps below 3 :

[0090] Step S510: Assume that the coordinates of the three displacement sensors are (x 1 ,y 1 , z 41 )、(x 2 ,y 2 , z 42 ) and (x 3 ,y 3 , z 43 ), calculate the normal vector of the plane to be measured:

[0091]

[0092] in,

[0093]

[0094] Step S520: Calculate the pitch angle θ according to the following formula: 3 :

[0095]

[0096] In step S500, the error-compensated measured value z 41 、z 42 and z 43 , the yaw angle can be calculated by following the steps below

[0097] Step S530: Assume that the coordinates of the three displacement sensors are (x 1 ,y 1 , z 41 )、(x 2 ,y 2 , z 42 ) and (x 3 ,y 3 , z 43 ), calculate the normal vector of the plane to be measured:

[0098]

[0099] in,

[0100]

[0101] Step S540: Calculate the yaw angle according to the following formula:

[0102]

[0103] In step S500, the pitch angle θ can be calculated according to the following formula: 3 To perform error compensation:

[0104] θ is θ 3 Pitch angle after error compensation, k 2 The vertical coordinate of the pitch angle fitting curve is θ 3 The slope of the measurement point, b 2 The vertical coordinate of the pitch angle fitting curve is θ 3 The intercept of the measurement point.

[0105] The step S500 can calculate the yaw angle according to the following formula: To perform error compensation: for Yaw angle after error compensation, k 3 The ordinate of the yaw angle fitting curve is The slope of the measurement point, b 2 The ordinate of the yaw angle fitting curve is The intercept of the measurement point.

[0106] In addition, in this embodiment, the pitch angle may be the angle formed by the rotation of the plane to be measured around the x-axis and the xoz plane; the yaw angle may 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: Δz = z ij -Z; the step S300 further comprises: calculating the measurement error of the pitch angle: Δθ = θ 2 -θ 1 ; Step S400 also includes: calculating the measurement error of the yaw angle: The present invention calculates the measurement errors of the displacement sensor, the pitch angle and the yaw angle, which can more intuitively reflect the error size and facilitate user debugging.

[0107] 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.

[0108] 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, and 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.

[0109] Those skilled in the art will readily appreciate other embodiments of the present invention 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 present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0110] It will be appreciated that the invention is not limited to the precise construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from its scope. The scope of the invention is governed solely by the appended claims.

Claims

1. A high-precision posture measurement error compensation method, characterized in that: include: Step S100, establishing 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; establishing 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: reset the pitching stage and the rotation stage to zero, gradually move the linear stage, and record the measured values ​​z respectively measured by the three displacement sensors for each movement. 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 measured 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, gradually rotate the pitch stage, and record the measured values ​​z respectively 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; the corresponding measurement fitting curve is used to respectively 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 respectively measured by the three displacement sensors for each rotation. 31 、z 32 and z 33 And the yaw angle measured by the rotation stage The corresponding measurement fitting curve is used 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 After that, firstly, the measured value z is respectively calculated according to the corresponding measurement fitting 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 for error; 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 respectively in the following manner: for the measured value z measured by each displacement sensor 1j , j is the serial number of the displacement sensor and its value is 1, 2 and 3. The measured value Z measured by the linear displacement stage is the horizontal coordinate of the measuring point on the measurement fitting curve. The measured value z of the displacement sensor corresponding to the time is 1j is the ordinate of the corresponding measurement point on the measurement 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 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 performs the following operations on the measured value z: 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 performs the following operations on the measured 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; The step S500 performs the following steps on the measured value z: 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, a=(y2-y1)*(z 23 -z 21 )-(y3-y1)*(z 22 -z 21 ) b=(z 22 -z 21 )*(3-x1) - ( z 23 -z 21 )*(x2−x1)? <h2 style=";text-align:left;direction:ltr">c = (x2 - x1) * (y3 - y1)<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> (x3-x1)*(y2-y1) 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, a=(y2-y1)*(z 43 -z 41 )-(y3-y1)*(z 42 -z 41 ) b=(z 42 -z 41 )*(x3-x1) - ( z 43 -z 41 )*(x2−x1)? <h2 style=";text-align:left;direction:ltr">c = (x2 - x1) * (y3 - y1)<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> (x3-x1)*(y2-y1) 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, a=(y2-y1)*(z 33 -z 31 )-(y3-y1)*(z 32 -z 31 ) b=(z 32 -z 31 )*(x3−x1)−(z 33 -z 31 )*(x2−x1)? c=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1) 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, a=(y2-y1)*(z 43 -z 41 )-(y3-y1)*(z 42 -z 41 ) b=(z 42 -z 41 )*(x3-x1) - ( z 43 -z 41 )*(x2−x1)? <h2 style=";text-align:left;direction:ltr">c = (x2 - x1) * (y3 - y1)<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> (x3-x1)*(y2-y1) 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 displacement stage is used as the horizontal coordinate of the measuring point on the pitch angle fitting curve, and the pitch angle θ2 calculated at the corresponding time is used as the vertical coordinate of the corresponding measuring point on the pitch angle fitting curve, and a corresponding number of discrete scattering points are obtained; a first-order fitting is performed on the discrete measuring points to obtain the pitch angle fitting curve: θ2=θ1·k2+b2, wherein k2 is the slope of the corresponding measuring point in the pitch angle fitting curve, and b2 is the intercept of the corresponding measuring 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 scattering 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; In step S500, the yaw angle is calculated according to the following formula: To perform error compensation: for The yaw angle after error compensation, k3 is the yaw angle fitting curve with the ordinate 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 measured plane rotating around the x-axis and the xoz plane, and the pitch displacement stage rotates around the x-axis; the yaw angle is the angle formed between the measured plane rotating around the y-axis and the xoy plane, and the rotation displacement 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, measuring value z 1j , the values ​​of j are 1, 2 and 3, and the measurement error of the displacement sensor is calculated: 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 respectively; the displacement sensor is a contact displacement sensor, which is fixed on the plane to be measured.

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