Method for optimizing cam curve of high-zoom-ratio sighting telescope

Abstract

The invention discloses an optimization method for a cam curve of a high-zoom-ratio sighting telescope, particularly relates to the technical field of sighting telescope design, and solves the technical problems that in the prior art, the pressure lead angle of a cam curve of a traditional compensation set in the high-zoom-ratio sighting telescope is too large, resistance is too large in the operation process of a zoom assembly, and even a movement mechanism is stuck. According to the technical scheme, when an initial cam curve is optimized, the distribution value of a cam rotation angle is automatically adjusted; the peak value of the cam curve pressure lead angle can be effectively reduced, the overall pressure lead angle of the cam curve is smaller than a limit value, the maximum lead angle is reduced as much as possible under the limit of the cam outer pipe, and curve smoothness is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of sight design, and in particular to a method for optimizing a cam curve of a high-variable-ratio sight. Background Art

[0002] As an accessory of shooting equipment, the scope is widely used in competitions, hunting entertainment, and battlefield warfare. The variable magnification scope can continuously change the magnification when in use, realizing the advantages of a large search field of view at low magnification and high aiming accuracy at high magnification. In order to give full play to its power, a large field of view and high variable magnification scope came into being.

[0003] The zoom scope can be regarded as a combination of a telescope system and a zoom component. The structure of a two-element "positive-positive" optical focal lens group is the most common as a zoom component. The two positive optical focal lens groups close to the objective lens are called the zoom group, and the ones close to the eyepiece are called the compensation group. When zooming, the zoom group and the compensation group move along the axial direction of the scope according to a certain rule under the drive of the cam to achieve continuous zooming. The cam curve shows the relationship between the moving distance of the zoom group and the moving distance of the compensation group. Whether the cam curve is reasonable will directly affect the imaging quality, optical axis stability and cam processing quality. For low zoom ratio scopes, the zoom group usually moves linearly, and the compensation group compensates for nonlinear movement to meet the use requirements. For high zoom ratio scopes, as the linear movement range of the zoom group increases, the compensation group curve will have problems such as too small axial inclination and too large pressure rise angle of the cam curve, which will cause excessive resistance during the operation of the zoom component, and even the motion mechanism will be stuck.

[0004] For general zoom components, if the pressure rise angle of the cam curve is too large, the pressure rise angle can be reduced by increasing the rotation angle or diameter of the cam outer tube. However, due to the limitations of the scope's external dimensions and component strength, the rotation angle of the scope's cam outer tube is generally not more than 260°, and the diameter is generally less than 30mm. Therefore, it is essential to optimize the cam curve of a high zoom ratio scope. The purpose is to reduce the maximum rise angle as much as possible under the limitation of the cam outer tube to ensure a smooth curve. Summary of the invention

[0005] Therefore, the present invention solves the technical problem that in the prior art, with high zoom ratio sights, as the linear movement range of the zoom group becomes larger, the compensation group curve will have an axial inclination angle that is too small and the cam curve pressure rise angle is too large, which will cause excessive resistance during the operation of the zoom component and even the movement mechanism to get stuck. The present invention provides an optimization method for the cam curve of a high zoom ratio sight, which can reduce the maximum rise angle as much as possible under the limitation of the cam outer tube, ensure the smoothness of the curve, and solve the problems of the traditional compensation group cam curve in high zoom ratio sights that have a pressure rise angle that is too large, the resistance during the operation of the zoom component is too large, and even the movement mechanism is stuck.

[0006] The present invention provides a method for optimizing a cam curve of a high-variable-ratio sight, comprising the following steps:

[0007] Step 1: Output the structural parameters of the zoom component through the optical design software, and output the position parameters of the object side principal surface and the image side principal surface of the zoom group and the compensation group;

[0008] Step 2: Determine the rotation angle and diameter of the cam outer tube;

[0009] Step 3: Use Gaussian theory to solve the parameters of multiple sampling point data during the zoom process, such as object distance, interval, etc., and combine them with the parameters of step 1 to form actual parameters;

[0010] Step 4: Obtain the initial cam curve of linear distribution according to step 2 and step 3;

[0011] Step 5: Under the premise of ensuring that the axial positions of the zoom group and the compensation group remain unchanged, adjust the distribution relationship of the cam angle to change the pressure rise angle of the cam curve, and obtain the optimized cam curve based on the redistributed cam angle data.

[0012] Furthermore, the distribution relationship of the cam angle is adjusted to change the pressure rise angle of the cam curve. The relationship between the pressure rise angle α of the cam curve and the distance Δz between two adjacent points of the variable magnification component along the axial motion position and the cam angle Δθ is used as the objective function. The corresponding program code is written using Matlab to calculate the pressure rise angle value of each sampling point in turn, and assign the corresponding cam angle weight. The calculation process is iterated multiple times to automatically find the optimal distribution angle of the cam angle.

[0013] Furthermore, based on the reallocated cam angle data to obtain an optimized cam curve, the variable magnification group and the compensation group share a set of cam angle data, and at this time, the pressure rise angle values ​​of the respective cam curves are less than the limit value.

[0014] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0015] 1. The present invention provides an optimization method for a cam curve of a high zoom ratio scope. When optimizing the initial cam curve, the distribution value of the cam angle is automatically adjusted, which can effectively reduce the peak value of the pressure rise angle of the cam curve, so that the overall pressure rise angle of the cam curve is less than the limited value, and the maximum rise angle is reduced as much as possible under the limitation of the cam outer tube, ensuring the smoothness of the curve, and solving the problems of excessive pressure rise angle of the cam curve of the traditional compensation group in the high zoom ratio scope, excessive resistance during the operation of the zoom component, and even jamming of the motion mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a flow chart of the cam curve optimization method of the present invention.

[0018] Figure 2 The traditional 1 to 10 x Graph of the initial cam curve for a zoom scope.

[0019] Figure 3 The traditional 1 to 10 x A plot of the pressure rise angle of the initial cam curve of a zoom scope.

[0020] Figure 4 This is an optimized cam curve diagram of a preferred embodiment of the present invention.

[0021] Figure 5 This is a pressure rise angle diagram of the optimized cam curve of the preferred embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] Embodiment 1:

[0024] This embodiment provides a method for optimizing the cam curve of a high zoom ratio sight. The specific implementation steps are as follows: Figure 1 As shown:

[0025] Step 1: Output the structural parameters of the zoom component through the optical design software, and output the position parameters of the object side principal surface and image side principal surface of the zoom group and compensation group.

[0026] Determine the vertical axis magnification β of the zoom group at low magnification 1l , the distance d between the main surface of the image side of the zoom group and the main surface of the object side of the compensation group l , the focal lengths f1 and f2 of the zoom group and the compensation group determine the total displacement l of the zoom group during the zoom process.

[0027] Step 2: Determine the rotation angle and diameter of the cam outer tube. After setting the cam outer tube diameter, the movement increment Δx of the sampling data point can be calculated and combined with the total displacement data of the zoom group in step 1, the initial cam outer tube rotation angle data can be further calculated.

[0028] Step 3: Use Gaussian theory to solve the parameters of multiple sampling point data during the zoom process, such as object distance, interval, etc., and combine them with the parameters of step 1 to form actual parameters.

[0029] In the process of solving the zoom Gaussian parameters, the position of the zoom group when it is not moved is taken as the starting point, and then the zoom group moves in sequence by integer multiples of Δx until the displacement of the zoom group exceeds the maximum magnification. The Gaussian theoretical formula is used to calculate the zoom data corresponding to different displacements of the zoom group.

[0030] The object distance value calculated by using Gaussian theory is only a theoretical value. After combining the parameters in step 1, the actual distance L2 from the first surface of the zoom lens group to the object plane and the actual distance L3 from the first surface of the compensation lens group to the object plane are obtained.

[0031] Step 4: Obtain the initial cam curve of linear distribution according to steps 2 and 3.

[0032] After the above steps, a large number of sampling data points of the zoom component in the zoom process can be obtained, and the initial cam curves of the zoom group and the compensation group are drawn with the rotation angle of the initial cam outer tube as the y-axis data and the axial position values ​​L2 and L3 of the zoom group and the compensation group as the x-axis data. When drawing the initial cam curves of the zoom group and the compensation group, the zoom group and the compensation group share a set of cam rotation angle data.

[0033] Calculate the pressure rise angle of the initial cam curve and the pressure rise angle of the cam curve α and Δz The relationship between and Δθ is:

[0034]

[0035] In the formula Δz is the distance between two adjacent points of the zoom component along the axial motion, Δθ is the angle of rotation of the cam, r is the radius of the cam outer tube. If the pressure rise angles of the initial zoom group cam curve and the compensation group cam curve are both lower than the design peak value, step 5 can be skipped and the initial cam curve can be directly output. However, for high zoom ratio scopes, the pressure rise angle of the initial compensation group cam curve designed by the traditional method is often too large, and the initial cam curve needs to be optimized.

[0036] In addition, in order to further improve the accuracy of the cam zoom, before optimizing the initial cam curve, it is necessary to supplement the axial position data of the zoom component at the integer magnification sampling points. When the magnification is known, the Gaussian zoom formula can be used to inversely calculate the corresponding axial positions L2 and L3 of the zoom component.

[0037] Step 5: Under the premise of ensuring that the axial positions of the zoom group and the compensation group remain unchanged, adjust the distribution relationship of the cam angle to change the pressure rise angle of the cam curve, and obtain the optimized cam curve based on the redistributed cam angle data.

[0038] When redistributing the cam rotation angle of each sampling point data, the cam curve pressure rise angle α and Δz The relationship between Δθ and Δθ is taken as the objective function, and the corresponding program code is written using Matlab. The pressure rise angle value of each sampling point is calculated in turn, and the corresponding cam angle weight is assigned. The calculation is processed iteratively for multiple times to automatically find the optimal distribution angle of the cam angle. After the cam curve is optimized, the zoom group and the compensation group share a set of cam angle data. At this time, the pressure rise angle values ​​of their respective cam curves should be less than the limit value.

[0039] Embodiment 2:

[0040] The technical parameters of the sight optimized by the above embodiment are as follows: the maximum aperture of the objective lens is 30 mm, the maximum field of view angle is 23°, and the range of 1 to 10 x Continuous zoom. The zoom component parameters are: the conjugate distance of the zoom component is 125.515mm, the zoom range is 0.334~3.340; 1~10 x During the zoom process, the total movement of the zoom group is 62.125mm, and the total movement of the compensation group is 66.890mm. Due to the limitations of the overall size and component strength of the sight, the rotation angle of the sight cam outer tube is set to be less than 250°, and the diameter of the cam outer tube is 29mm.

[0041] Figure 2 Shown is the traditional 1 to 10 x The initial cam curve of the continuous zoom scope. The zoom group and the compensation group share a set of cam angle data. The cam angle values ​​of the sampling point data increase by 1° from 0, and the total angle is 246°. The outer tube of the scope cam rotates 246° continuously from 0 to complete the 1-10 times zoom. During the zoom process, the zoom group components perform linear motion, and the compensation group components perform nonlinear motion.

[0042] Figure 3 The traditional 1 to 10 xThe pressure rise angle diagram of the initial cam curve of the continuously variable magnification scope. It can be seen from the figure that if the cam curve is designed by dividing the cam angle in increments of 1°, the pressure rise angle of the variable magnification group cam curve is 45°, and the pressure rise angle of the compensation group cam curve varies from -13.9008° to 88.1953°. A positive value of the compensation group pressure rise angle indicates that the compensation group moves toward the objective lens, and a negative value of the pressure rise angle indicates that the compensation group moves away from the objective lens. When the cam curve is conventionally designed, the pressure rise angle reaches 60° when the cam rotation angle is 204°, and the magnification of the scope is only about 4 times. Therefore, this cam curve cannot meet the use requirements.

[0043] Figure 4 : is the optimized cam curve diagram of the preferred embodiment of the present invention. Figure 4 It can be seen that, using the optimization method of the high zoom ratio sight cam curve of the present invention, the total cam rotation angle required for the 1-10 times zoom of the final optimized cam curve is 249.44°, which is lower than the setting value of 250° of the rotation angle of the outer tube of the sight cam. The zoom group and the compensation group share a set of cam rotation angle data, and both the zoom group and the compensation group perform nonlinear motion. During the 1-10 times zoom process, the total movement of the zoom group and the compensation group is consistent with the movement before optimization, and the curve is smooth and fluent as a whole without obvious inflection points during the zoom process.

[0044] Figure 5 The pressure rise angle diagram of the optimized cam curve of the preferred embodiment of the present invention is shown in FIG. Figure 5 It can be seen that the pressure rise angle of the optimized variable magnification group cam curve ranges from 2.0798° to 57.7919°, and the pressure rise angle of the compensation group cam curve ranges from -21.4469° to 57.9997°. The peak values ​​of the pressure rise angle are both lower than the setting value of 58° in the optimization program, and also lower than the commonly used peak value of 60° in engineering manufacturing, which meets the design requirements.

[0045] In summary, the cam curve optimization method proposed in the present invention realizes the optimization of the cam curve of a 1-10x high zoom ratio scope, and solves the problems of excessive pressure rise angle of the cam curve of the traditional compensation group in the high zoom ratio scope, excessive resistance during the operation of the zoom component, and even the jamming of the motion mechanism. The optimized cam curve zoom process is continuous, smooth, and stable.

[0046] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for optimizing a cam curve of a high zoom ratio sight, characterized in that: The steps include: S1: Output the structural parameters of the zoom component through the optical design software, and output the position parameters of the object side principal surface and the image side principal surface of the zoom group and the compensation group; S2: Determine the rotation angle and diameter of the cam outer tube; S3: Solving the parameters of multiple sampling point data during the zoom process, including object distance and interval, and combining them with the parameters of step S1 to form actual parameters; S4: Obtaining a linearly distributed initial cam curve according to the data of step S2 and step S3; S5: Under the premise of ensuring that the axial positions of the zoom group and the compensation group remain unchanged, the distribution relationship of the cam angle is adjusted to change the pressure rise angle of the cam curve, and the optimized cam curve is obtained based on the reallocated cam angle data.

2. The method for optimizing the cam curve of a high zoom ratio sight according to claim 1, characterized in that: The step S3 is solved by using Gaussian theory.

3. The method for optimizing the cam curve of a high zoom ratio sight according to claim 2, characterized in that: The distribution relationship of adjusting the cam rotation angle in step S5 to change the pressure rise angle of the cam curve is based on the cam curve pressure rise angle α and the distance Δz between two adjacent points of the variable power assembly along the axial movement position and the cam rotation angle. Δ θ The relationship between is taken as the objective function, and the corresponding program code is written to calculate the pressure rise angle value of each sampling point in turn, and assign the corresponding cam angle weight. After multiple iterative calculations, the optimal distribution angle of the cam angle is automatically found.

4. The method for optimizing the cam curve of a high zoom ratio sight according to claim 3, characterized in that: In the step S5, an optimized cam curve is obtained based on the reallocated cam angle data, and the zoom group and the compensation group share a set of cam angle data.

5. The method for optimizing the cam curve of a high zoom ratio sight according to claim 4, characterized in that: In the step S5, Matlab is used to write corresponding program codes.

6. The method for optimizing the cam curve of a high zoom ratio sight according to claim 5, characterized in that: Cam curve pressure rise angle α and Δz and Δ θ The relationship is: r is the radius of the cam outer tube.

7. The method for optimizing the cam curve of a high zoom ratio sight according to claim 3, characterized in that: In the process of solving the problem using Gaussian theory in step S3, the position of the zoom group when it is not moved is taken as the starting point, and then the zoom group moves in sequence by integer multiples of Δx until the displacement of the zoom group exceeds the maximum magnification, and the zoom data corresponding to different displacements of the zoom group are calculated using the Gaussian theory formula.

8. The method for optimizing the cam curve of a high zoom ratio sight according to claim 4, characterized in that: The pressure rise angle values ​​of the cam curves of the variable magnification group and the compensation group are both smaller than the limit value.

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