Precise non-contact angle measurement method and device for complex profile control wing

Abstract

The invention relates to a precise non-contact angle measurement method and device for a complex profile control wing, and belongs to the technical field of shell manufacturing. The method comprises the steps that three sets of non-collinear laser displacement sensors are symmetrically arranged, and it is guaranteed that laser beams are parallel to one another and perpendicular to a plumb plane; calibrating a measuring optical axis by using a precise piezoelectric actuator, and calculating laser spot space coordinate vectors at different moments according to a laser triangulation principle; calculating and solving the deflection angle through the normal vector of the reconstructed plane before and after deflection of the rudder wing; according to the method, non-contact measurement of the deflection angle of the complex-profile rudder wing is realized by utilizing a plurality of groups of symmetrically arranged laser displacement sensors based on a differential plane reconstruction principle; the technical limitations of low test efficiency, poor precision, visual field shielding based on visual measurement, data loss and the like in the existing rudder wing contact type indirect rotation angle measurement are solved, and the accurate measurement of the micro rotation angle of the rudder wing can be efficiently and accurately realized.

Description

Technical Field

[0001] The present invention relates to the technical field of artillery shell manufacturing, and in particular to a method and device for measuring the precise non-contact angle of a complex-shaped rudder wing. Background Art

[0002] To ensure the precise strike of guided projectiles, rudders control the flight attitude and trajectory of the projectile. Therefore, the rotation angle of complex rudders must be precisely accurate. Since rudder deflection is achieved through a transmission chain consisting of a power mechanism, an actuator, and a motion mechanism, errors introduced in the transmission link will result in an error between the actual rudder deflection angle and the control command deflection angle. Therefore, to achieve closed-loop / semi-closed-loop error compensation for the rudder angle, a high requirement for angle measurement accuracy is placed on 0.03° (<1 mrad).

[0003] The existing quality inspection of the rudder wing angle of guided projectiles mainly relies on the servo motor of the detection unit to rotate at the same angle because the rudder wing presents a complex surface with asymmetric curvature. The accuracy of the rudder wing angle is evaluated by recording the change in the contact load of the force sensor. The above-mentioned contact-type indirect angle measurement method based on circular grating has the technical limitations of low test efficiency and poor accuracy. At present, the non-contact measurement of rudder wing angle at home and abroad mainly includes laser non-contact and angle measurement technology based on vision measurement. The three-dimensional spatial coordinates of the feature points of the complex rudder wing surface are collected and reconstructed through binocular or multi-eye vision systems. However, the visual inspection system is easily blocked by the field of view, and it is easy to lose information when reconstructing the surface features of the object through image extraction, which introduces additional measurement errors. In addition, the measurement accuracy of visual measurement technology is low.

[0004] As the measurement accuracy of linear displacement sensors such as optical fiber and laser has reached the nanometer level and the installation size tends to be miniaturized, a new idea is provided for the measurement of rudder angle. Usually, the linear displacement is measured by sensor and then the angle is converted, but its applicability to complex rudder surfaces becomes poor. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, such as poor applicability and low measurement accuracy for complex-shaped rudder wings, the present invention proposes a method and device for precise non-contact angle measurement of complex-shaped rudder wings, thereby solving the problems existing in the existing technology.

[0006] A method for precise non-contact angle measurement of complex rudder wings comprises the following steps: The three laser spots formed by the unilateral laser displacement sensor on the complex rudder wing and the three laser spots on its symmetrical side for obtaining the initial position of the complex rudder wing; Reconstruct the first plane triangle and the second plane triangle respectively according to the three laser spots formed by the complex rudder wing at the beginning on the single-side laser displacement sensor and the three laser spots formed on the symmetrical side; The rudder wing under test is rotated by a certain angle about the plumb line through a steering gear control command, and three laser spots formed by a single-sided laser displacement sensor at the position of the rotated rudder wing and three laser spots on the symmetrical side are obtained; a third plane triangle and a fourth plane triangle are reconstructed based on the three laser spots formed by the single-sided laser displacement sensor at the position of the rotated rudder wing and the three laser spots on the symmetrical side; The rudder wing deflection angle is obtained by calculating the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle.

[0007] Furthermore, the calculating of the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle specifically includes the following steps: According to the principle of laser triangulation, calculate different moments t i The laser spot space coordinate vector X i ; The spatial coordinate vector of the laser spot is X i Substitute into space to reconstruct the plane equation , get the normal vector n of the reconstructed plane triangle 1i and n 2i , where i = 0, 1 is: ; ; When i = 0, the normal vectors of the first plane triangle and the third plane triangle are n 10 、n 20 , when i = 1, the normal vectors of the second plane triangle and the fourth plane triangle are n 11 、n 21 ; Then the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle is: .

[0008] Furthermore, the laser triangulation principle is used to calculate the different time t i The laser spot space coordinate vector X i , specifically including the following steps: The precision piezoelectric actuator is moved to different sections through control instructions, and the linear displacement Δ of different sections relative to the initial reference position is recorded. L i ; The three sets of laser optical axis equations on one side are: ; Where X=[ x , y , z ],A=[ a , b , c ],B=[ d , e , f ], a 、 b 、 c 、 d 、 e 、 f are the coefficients of the linear equation of the laser beam space; According to the principle of laser triangulation, different time differences Δ are obtained t i and linear displacement Δ L i The relationship between: ; The different time differences Δ t i and linear displacement Δ L i The relationship between and the three sets of laser optical axis equations on one side are solved together to obtain the corresponding time t i The spatial coordinate vector of the laser spot is X i .

[0009] Furthermore, the rudder wing deflection angle is obtained by using the differential plane reconstruction principle according to the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle. θ for: ; in, and are the normal vector coefficients of the reconstructed plane on both sides of the rudder at different times.

[0010] Furthermore, by symmetrically arranging three groups of non-collinear laser displacement sensors on each side of the complex rudder wing, three laser spots formed by the single-sided laser displacement sensor on the complex rudder wing and three laser spots on the symmetrical side are obtained at the initial position of the rudder wing.

[0011] Furthermore, it also includes symmetrically arranging three groups of non-collinear laser displacement sensors on each side of the rudder wing, using a fiber optic collimator to calibrate each group of laser displacement sensors to be perpendicular to the plumb bob plane, and the laser beams of each group of laser displacement sensors are parallel to each other.

[0012] The present invention also provides a device for measuring the precise non-contact angle of a complex rudder wing, comprising: An acquisition module, used to acquire the initial position of the complex rudder wing by the three laser spots formed by the single-sided laser displacement sensor on the complex rudder wing and the three laser spots on its symmetrical side; A first reconstruction module is used to reconstruct a first plane triangle and a second plane triangle according to three laser spots formed by the unilateral laser displacement sensor on the complex rudder wing at the beginning and three laser spots formed on the symmetrical side; The second reconstruction module is used to rotate the rudder wing under test around the plumb line by a certain angle through a steering gear control instruction, thereby obtaining three laser spots formed by the unilateral laser displacement sensor at the position of the rotated rudder wing and three laser spots on the symmetrical side; and reconstruct the third plane triangle and the fourth plane triangle based on the three laser spots formed by the unilateral laser displacement sensor at the position of the rotated rudder wing and the three laser spots on the symmetrical side. The calculation module is used to obtain the rudder wing deflection angle by calculating the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle.

[0013] The present invention provides a method for precise non-contact angle measurement of complex rudder wings, which has the following beneficial effects: The present invention obtains three laser spots formed by a single-sided laser displacement sensor on the complex rudder wing and three laser spots on its symmetrical side, and reconstructs the plane triangles of each side of the rudder wing before and after rotation. Based on the principle of differential plane reconstruction, non-contact measurement of the deflection angle of the complex rudder wing is achieved. This not only solves the technical limitations of the existing contact-type indirect angle measurement of the complex rudder wing of guided projectiles, such as low test efficiency and poor accuracy, and field of view obstruction and data loss based on visual measurement, but also can achieve efficient and accurate measurement of small angles of the rudder wing, providing technical guarantee for the precise strike of guided projectiles and closed-loop / semi-closed-loop error compensation of the rudder wing angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart of a method for precise non-contact angle measurement of complex rudder wings based on the differential plane reconstruction principle in an embodiment of the present invention; Figure 2 Schematic diagram of the arrangement of differential multiple groups of non-collinear laser displacement sensors in the servo under test and its typical complex rudder blades and angle measurement device in an embodiment of the present invention; Figure 3 Schematic diagram of the principle of obtaining the optical axis space equation of the laser displacement sensor using a precision piezoelectric actuator in an embodiment of the present invention; Figure 4 Schematic diagram of triangulation displacement measurement principle based on laser displacement sensor in an embodiment of the present invention; Figure 5Schematic diagram of the principle of light spot reconstruction plane of the differential laser displacement sensor for measuring the angle of complex rudder wing in an embodiment of the present invention; Figure 6 Schematic diagram of a method for measuring the precise non-contact deflection angle of a rudder wing based on the differential plane reconstruction principle in an embodiment of the present invention. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0016] The present invention proposes a method for measuring the precise non-contact angle of complex rudder wings. Figure 1 As shown, the specific steps include: S1. Arrange three groups of non-collinear laser displacement sensors symmetrically. Each group of sensors is calibrated separately through a collimator and is perpendicular to the plumb line, and the laser beams are kept parallel to each other. The schematic diagram of the arrangement of multiple groups of non-collinear laser displacement sensors is shown in Figure 2 shown.

[0017] S2. Use high-precision linear motion platforms such as precision piezoelectric actuators to calibrate the measurement optical axes of the three sets of laser displacement sensors on each side, and use control instructions to move the precision piezoelectric actuators to different sections. i ( i =1, 2, 3, ..., n), record the linear displacement Δ of different sections relative to the initial reference position L i ( i = 1, 2, 3, ..., n).

[0018] S3. Calculate different times based on the principle of laser triangulation t i The laser spot space coordinate vector X i .

[0019] S4. Place the servo vertically in the complex-shaped rudder blade angle measurement device to ensure that the initial position of the rudder blade (denoted as M) is within the measurement range of the differential laser displacement sensor.

[0020] S5, recording position M of the single-sided laser displacement sensor on the complex rudder wing formed three laser spots are A 10 、B 10 、C 10 , then the laser spots on the symmetric side are A 11 、B 11 、C 11 , respectively reconstruct the plane triangle ΔA 10 B 10 C10 and ΔA 11 B 11 C 11 .

[0021] S6, use the steering gear control command to make the rudder wing under test rotate around the plumb line θ , recorded as position N, where the laser spot formed by the single-sided laser displacement sensor at position N is A 20 、B 20 、C 20 , then the laser spots on the symmetric side are A 21 、B 21 、C 21 , respectively reconstruct the plane triangle ΔA 20 B 20 C 20 and ΔA 21 B 21 C 21 .

[0022] S7. Define the reconstructed plane triangle ΔA respectively 10 B 10 C 10 and ΔA 20 B 20 C 20 The normal vector is n 10 、n 20 , similarly, the plane triangle ΔA 11 B 11 C 11 and ΔA 21 B 21 C 21 The normal vector is n 11 、n 21 , then the normal vector angle: (1) Rudder deflection angle θ for: (2) See also Figure 3 and Figure 4 , the three sets of laser optical axis equations on one side are: (3) Where: X=[ x , y , z ],A=[ a , b , c ],B=[ d , e , f ]; a ,b , c , d , e , f are the coefficients of the spatial straight line equation of the laser beam.

[0023] According to the principle of laser triangulation, the laser sends the laser through the focusing lens, the incident light acts on the measuring point of the measured surface, and the reflected light acts on the photosensitivity point of the CCD receiver through the receiving lens, such as Figure 4 As shown, the different time differences Δ t i (=t i -0) and linear displacement Δ L i Satisfy the following formula: (4) And by solving formula (3) and (4) together, we can get the corresponding time t i The spatial coordinate vector of the laser spot is X i ; See also Figure 5 and Figure 6 , substitute the spatial coordinates of the measured laser spot described in the present invention into the spatial reconstruction plane equation: (5) Then reconstruct the normal vector n of the plane triangle 1i and n 2i (i = 0, 1) can be expressed as: (6) (7) in, They correspond to the corresponding A1i, B1i, and Ci1 position points respectively.

[0024] That is, the rudder deflection angle measured according to the differential plane reconstruction principle is: (8) in, and are the normal vector coefficients of the reconstructed plane on both sides of the rudder at different times.

[0025] Example This embodiment provides a non-contact angle measurement method based on the differential plane reconstruction principle for the asymmetric curvature of a certain type of guided artillery projectile's complex rudder fin. The specific test steps are as follows: S1. Arrange the laser displacement sensors on each side in at least three non-collinearly symmetrical groups (select three groups for calculation), with a minimum spacing greater than the rudder wing thickness (4 mm). Use a fiber optic collimator to calibrate each group of laser displacement sensors to be perpendicular to the plumb bob, while maintaining parallel laser beams.

[0026] S2. Using a high-precision linear motion platform (stroke > 4mm) such as a precision piezoelectric actuator, and taking three sets of laser displacement sensors on one side as an example, calibrate the one-dimensional relative displacement increment data to obtain the measurement optical axis space equation X i The specific operation process includes: (1) recording the initial position and time of the precision piezoelectric actuator; (2) moving the precision piezoelectric actuator to at least three groups of cross-sectional positions i (i = 1, 2 and 3) through voltage control instructions, and recording the linear displacement ΔL of different cross-sectional positions relative to the initial reference position. i (1 mm, 1.2 mm and 2.7 mm); S3. By fitting the spatial coordinates of the measurement spot positions in different sections using the least squares method, the three groups of laser displacement sensors on one side are coordinate-converted into parameter matrices.

[0027] (9) Similarly, the coordinate parameter matrices of the three groups of laser displacement sensors on the symmetric side are: (10) S4. Place the servo vertically in the complex-shaped rudder blade angle measurement device to ensure that the initial position of the rudder blade (denoted as M) is within the measurement range of the differential laser displacement sensor.

[0028] S5, recording position M of the single-sided laser displacement sensor on the complex rudder wing formed three laser spots are A 10 、B 10 、C 10 , then the laser spots on the symmetric side are A 11 、B 11 、C 11 , respectively reconstruct the plane triangle ΔA 10 B 10 C 10 and ΔA 11 B 11 C 11 .

[0029] S6, use the steering gear control command to make the rudder wing under test rotate around the plumb line θ , recorded as position N, where the laser spot formed by the single-sided laser displacement sensor at position N is A 20 、B 20 、C 20 , then the laser spots on the symmetric side are A 21、B 21 、C 21 , respectively reconstruct the plane triangle ΔA 20 B 20 C 20 and ΔA 21 B 21 C 21 ; S7. Calculate the relative displacement values ​​of the laser displacement sensor on one side (0.040 mm, 0.038 mm, 0.031 mm) when the rudder wing deflects from position M to position N. Similarly, calculate the relative displacement values ​​of the laser displacement sensor on the symmetrical side (-0.034 mm, -0.029 mm, -0.027 mm). S8. Combining formulas (9) and (10), substitute the relative displacement value of the laser spot into the reconstructed plane space equation and obtain its normal vector n 1i and n 2i (i=0, 1), at this time the rudder deflection angle is 1.804°.

[0030] See also Figures 1 to 6 As shown, the present invention's method for precise non-contact angle measurement of complex surface rudder wings based on the differential plane reconstruction principle realizes non-contact measurement of the deflection angle of complex surface rudder wings based on the differential plane reconstruction principle by adopting multiple groups of symmetrically arranged laser displacement sensors. This method can not only solve the technical limitations of low test efficiency, poor accuracy, and visual measurement-based field of view occlusion and data loss in the existing contact-type indirect angle measurement of complex surface rudder wings of guided artillery shells, but can also efficiently and accurately realize precise measurement of small angles of rudder wings, providing technical support for the precise strike of guided artillery shells and closed-loop / semi-closed-loop error compensation of rudder wing angles. In addition, the instrumentation required for this method is relatively simple to set up, and can realize non-contact measurement of continuous deflection angles of complex surface rudder wings. It is easy to operate and highly practical.

[0031] Based on the above inventive concept, the present invention also proposes a device for measuring the precise non-contact angle of complex rudder wings, comprising: The acquisition module is used to acquire the initial position of the complex rudder wing by the single-sided laser displacement sensor, forming three laser spots on the complex rudder wing and three laser spots on its symmetrical side.

[0032] The first reconstruction module is used to reconstruct the first plane triangle and the second plane triangle according to the three laser spots formed by the unilateral laser displacement sensor on the complex rudder wing at the beginning and the three laser spots formed on the symmetrical side.

[0033] The second reconstruction module is used to rotate the rudder wing under test around the plumb line by a certain angle through the servo control command, thereby obtaining three laser spots formed by the unilateral laser displacement sensor at the position of the rudder wing after rotation and three laser spots on the symmetrical side; and reconstruct the third plane triangle and the fourth plane triangle based on the three laser spots formed by the unilateral laser displacement sensor at the position of the rudder wing after rotation and the three laser spots on the symmetrical side.

[0034] The calculation module is used to obtain the rudder wing deflection angle by calculating the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle.

[0035] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for precise non-contact angle measurement of complex rudder wings, characterized in that: The following steps are involved: The unilateral laser displacement sensor for obtaining the initial position of the complex rudder wing forms three laser spots on the complex rudder wing and three laser spots on its symmetrical side; Reconstruct the first plane triangle and the second plane triangle respectively according to the three laser spots formed by the complex rudder wing at the beginning on the single-side laser displacement sensor and the three laser spots formed on the symmetrical side; The rudder wing under test is rotated by a certain angle about the plumb line through a steering gear control command, and three laser spots formed by a single-sided laser displacement sensor at the position of the rotated rudder wing and three laser spots on the symmetrical side are obtained; a third plane triangle and a fourth plane triangle are reconstructed based on the three laser spots formed by the single-sided laser displacement sensor at the position of the rotated rudder wing and the three laser spots on the symmetrical side; The rudder wing deflection angle is obtained by calculating the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle.

2. The method for precise non-contact angle measurement of complex rudder wings according to claim 1, characterized in that: The calculating of the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle specifically includes the following steps: According to the principle of laser triangulation, calculate different moments t i The laser spot space coordinate vector X i ; The spatial coordinate vector of the laser spot is X i Substitute into space to reconstruct the plane equation , get the normal vector n of the reconstructed plane triangle 1i and n 2i , where i = 0, 1 is: ； ； When i = 0, the normal vectors of the first plane triangle and the third plane triangle are n 10 、n 20 , when i=1, the normal vectors of the second plane triangle and the fourth plane triangle are n 11 、n 21 ; Then the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle is: 。 3. The method for precise non-contact angle measurement of complex rudder wings according to claim 2, characterized in that: According to the principle of laser triangulation, the calculation of different moments t i The laser spot space coordinate vector X i , specifically including the following steps: The precision piezoelectric actuator is moved to different sections through control instructions, and the linear displacement Δ of different sections relative to the initial reference position is recorded. L i ; The three sets of laser optical axis equations on one side are: ; Where X=[ x , y , z ],A=[ a , b , c ],B=[ d , e , f ], a 、 b 、 c 、 d 、 e 、 f are the coefficients of the linear equation of the laser beam space; According to the principle of laser triangulation, different time differences Δ are obtained t i and linear displacement Δ L i The relationship between: ; The different time differences Δ t i and linear displacement Δ L i The relationship between and the three sets of laser optical axis equations on one side are solved together to obtain the corresponding time t i The spatial coordinate vector of the laser spot is X i .

4. The method for precise non-contact angle measurement of complex rudder wings according to claim 2, characterized in that: According to the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle, the rudder deflection angle is obtained by using the differential plane reconstruction principle. θ for: ； in, and are the normal vector coefficients of the reconstructed plane on both sides of the rudder at different times.

5. The method for precise non-contact angle measurement of complex rudder wings according to claim 1, characterized in that: By symmetrically arranging three groups of non-collinear laser displacement sensors on each side of the complex rudder wing, three laser spots formed by the single-sided laser displacement sensor on the complex rudder wing and three laser spots on the symmetrical side are obtained at the initial position of the rudder wing.

6. The method for precise non-contact angle measurement of complex rudder wings according to claim 5, characterized in that: The method also includes symmetrically arranging three groups of non-collinear laser displacement sensors on each side of the rudder wing, and using a fiber optic collimator to calibrate each group of laser displacement sensors to be perpendicular to the plumb bob plane, and the laser beams of each group of laser displacement sensors are parallel to each other.

7. A device for measuring the precision non-contact angle of complex rudder wings, characterized in that: include: An acquisition module, used to acquire the initial position of the complex rudder wing by the three laser spots formed by the single-sided laser displacement sensor on the complex rudder wing and the three laser spots on its symmetrical side; A first reconstruction module is used to reconstruct a first plane triangle and a second plane triangle according to three laser spots formed by the unilateral laser displacement sensor on the complex rudder wing at the beginning and three laser spots formed on the symmetrical side; The second reconstruction module is used to rotate the rudder wing under test around the plumb line by a certain angle through a steering gear control instruction, thereby obtaining three laser spots formed by the unilateral laser displacement sensor at the position of the rotated rudder wing and three laser spots on the symmetrical side; and reconstruct the third plane triangle and the fourth plane triangle based on the three laser spots formed by the unilateral laser displacement sensor at the position of the rotated rudder wing and the three laser spots on the symmetrical side. The calculation module is used to obtain the rudder wing deflection angle by calculating the angle between the normal vectors of the first plane triangle and the third plane triangle and the angle between the normal vectors of the second plane triangle and the fourth plane triangle.

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