Method for analyzing visual field outside helicopter cabin

Abstract

The invention belongs to the technical field of helicopter man-machine efficacy design, and particularly relates to a helicopter cabin outer visual field analysis method. The method comprises the following steps: firstly, converting all three-dimensional feature point sets of a view shielding object into a two-dimensional view discrete point set, extracting an edge point set of a view shielding region, fitting to generate a contour line, and forming a corresponding view shielding region, so as to obtain an external view region which is not obstructed by a driver; the method solves the problems of low precision, long time consumption and limited application range of a conventional cabin external visual field analysis method.

Description

Technical Field

[0001] The invention belongs to the technical field of helicopter human-machine efficiency design, and in particular relates to a method for analyzing visual field outside a helicopter cockpit. Background Art

[0002] The visual field outside the helicopter cockpit is an important way for the pilot to observe the environment outside the cabin. Usually, the equivalent area visual field diagram is used for visibility evaluation, that is, the visual field blocked by components / equipment such as structural parts and detection devices is drawn in the unobstructed visual field diagram with an azimuth angle of ±180° and a pitch angle of ±90° at the center of the pilot's designed eye position, so as to obtain the unobstructed external visual field area of ​​the pilot. At present, the visual field obstruction area in the visual field diagram is mainly obtained by extracting the three-dimensional boundary discrete point set of the visual field obstruction object, and then solving the visual field azimuth and pitch angle of each point relative to the designed eye position to form a two-dimensional visual field obstruction area edge point set and then fitting it. The disadvantage of this method is that the extracted three-dimensional boundary points are difficult to define as the edge points of the field of view occlusion area, especially the points with curved surface features, so that the formed field of view occlusion area deviates from the actual situation. At the same time, the extraction of three-dimensional boundary points has high requirements. If too few points are extracted, the fitting accuracy of the contour line of the two-dimensional field of view occlusion area is low, and the shape of the formed field of view occlusion area is easily distorted; if too many points are extracted, it will take a long time and it is easy to generate pseudo edge points of the field of view, which will directly affect the fitting of the field of view contour line and reduce the quality of the field of view occlusion area generation. Summary of the invention

[0003] The invention provides a helicopter cockpit external visual field analysis method, which solves the problems of low precision, long time consumption and limited application scope of the current cockpit external visual field analysis method.

[0004] In order to achieve the above object, the present invention adopts the following technical solution to achieve it.

[0005] A method for analyzing the visual field outside a helicopter cockpit comprises the following steps:

[0006] Step 1: Select the pilot's design eye position and give its three-dimensional point coordinates in the helicopter's full coordinate system, recorded as P0 (x0, y0, z0);

[0007] Step 2: Select the field of view obstruction arranged in the whole aircraft coordinate system, and obtain the corresponding three-dimensional point set coordinates P of the field of view obstruction i (x i ,y i ,z i )(i=1,2,…n);

[0008] Step 3: Design the eye position P0 based on the driver, and calculate the coordinates of each point P in the three-dimensional point set. i , obtain the corresponding two-dimensional field of view discrete points, and form a two-dimensional field of view discrete point set p i (u i,ν i )(i=1,2,…n), denoted as M;

[0009] Step 4: For any point p(u, ν) in the point set M, search for all points in M ​​whose Euclidean distance from point p(u, ν) is less than the preset distance, which is recorded as the point set E;

[0010] Step 5: Select any point p′(u′,ν′) in the point set E, and calculate the coordinates p″(u″,ν″) and p″′(u″′,ν″′) of the center of the rolling circle passing through p and p′ with a radius of R;

[0011] Step 6: Calculate the distances from other points in the point set E except point p′ to p″ and p″′;

[0012] If the distances from other points to point p″ or p″′ are all greater than the R value, point p(u,ν) is determined to be an edge point;

[0013] Step 7: If the distances from other points to point p″ or p″′ are not all greater than the R value, traverse all points in the point set E and rotate them to point p′;

[0014] Repeat steps 5 and 6. If point p(u, ν) is determined to be an edge point, stop judging this point and proceed to step 4 to judge the next point in M. If there is no point like p′ in all neighboring points in E, it means that point p(u, ν) is a non-edge point, and proceed to step 4 to judge the next point in M.

[0015] Step 8: Traverse all points in the point set M, obtain the edge point set of the field of view occlusion area, perform contour fitting, form the corresponding field of view occlusion area, and thus obtain the driver's unobstructed external field of view area.

[0016] Furthermore,

[0017] In step 3, for each point P in the three-dimensional point set coordinates i , obtain the corresponding two-dimensional field of view discrete points, and form a two-dimensional field of view discrete point set p i (u i ,ν i )(i=1,2,…n), specifically:

[0018] Solve point P by formula (1) i The corresponding field of view azimuth μ i and the pitch angle ν i , get the two-dimensional field of view discrete point set p i (u i ,ν i )(i=1,2,…n), denoted as M;

[0019]

[0020] Furthermore,

[0021] In step 4, the preset distance is 2R, where R is the given search rolling circle radius.

[0022] Furthermore,

[0023] In step 5, the coordinates p″(u″, ν″) and p″′(u″′, ν″′) of the center of the rolling circle passing through p and p′ and having a radius of R are calculated as follows:

[0024]

[0025] Where: Intermediate variable H

[0026]

[0027] Furthermore,

[0028] The helicopter cockpit is a parallel double-seat cockpit, a tandem double-seat cockpit or a single-row single-seat cockpit.

[0029] Furthermore,

[0030] The surface feature of the field of view blocking object is a plane, a regular curved surface, an irregular curved surface, or any combination of a plane, a regular curved surface, and an irregular curved surface.

[0031] Furthermore,

[0032] The search rolling circle radius adopts an empirical fixed value, or an adaptive radius with a fixed number of neighboring points.

[0033] Furthermore,

[0034] The contour line fitting method of the visual field occlusion area is least squares fitting, weighted regression fitting or spline fitting.

[0035] The present invention proposes a method for analyzing the visual field outside the helicopter cockpit. First, the three-dimensional feature point set of the visual field obstruction object is completely converted into a two-dimensional visual field discrete point set, the edge point set of the visual field obstruction area is extracted, and the contour line is fitted to form the corresponding visual field obstruction area, so as to obtain the unobstructed external visual field area of ​​the driver. It is suitable for visual field obstructions with various surface features, and can quickly and accurately reproduce the visual field obstruction area, greatly improving the quality of the visual field assessment outside the helicopter cockpit. This method has been successfully applied to a certain type of helicopter and can be applied to other helicopters in the future, and has certain engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the cockpit layout provided by an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of a two-dimensional field of view point set and edge point extraction under occlusion of a detection device provided in an embodiment of the present invention;

[0038] Figure 3 A schematic diagram for comparing the driver's external field of view provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings.

[0040] An embodiment of the present invention provides a method for analyzing the external field of view of a helicopter cockpit. First, all three-dimensional feature point sets of field of view obstructions are converted into two-dimensional field of view discrete point sets, and then edge point sets of field of view obstruction areas are extracted, and contour lines are generated by fitting to form corresponding field of view obstruction areas, thereby obtaining an unobstructed external field of view area for the pilot.

[0041] Specifically, a method for analyzing the visual field outside a helicopter cockpit comprises the following steps:

[0042] Step 1: Select the driver's eye position, such as Figure 1 As shown, the three-dimensional point coordinates in the helicopter's global coordinate system are given, denoted as P0(x0,y0,z0);

[0043] Step 2: Select the visual field obstruction arranged in the whole aircraft coordinate system, such as Figure 1 As shown, obtain the corresponding three-dimensional point set coordinates P i (x i ,y i ,z i )(i=1,2,…n);

[0044] Step 3: Design the eye position P0 based on the driver. i , the corresponding field of view azimuth μ is calculated by formula (1) i and the pitch angle ν i , get the two-dimensional field of view discrete point set p i (u i ,ν i )(i=1,2,…n), denoted as M; Figure 2 As shown, there are 2200 two-dimensional field of view points under the occlusion of the detection device, and 176 field of view occlusion points are extracted using the method of the present invention.

[0045]

[0046] Step 4: For any point p(u,ν) in the point set M, search for all points in M ​​whose Euclidean distance from point p is less than 2R, recorded as point set E, where R is the given search rolling circle radius;

[0047] Step 5: Select any point p′(u′,ν′) in the point set E, and calculate the coordinates p″(u″,ν″) and p″′(u″′,ν″′) of the center of the rolling circle passing through p and p′ with a radius of R:

[0048]

[0049] Where: Intermediate variable H

[0050]

[0051] Step 6: Calculate the distances from other points in the point set E except point p' to p", p''. If the distances from other points to point p'' or p'' are greater than the R value, then point p(u, ν) is determined to be an edge point;

[0052] Step 7: If the distances from other points to point p″ or p″′ are not all greater than the R value, traverse all points in the point set E and rotate to point p′. If there is a point in E that satisfies steps 5 and 6, point p is determined to be an edge point, stop judging the point, and proceed to step 4 to continue judging the next point in M. If there is no point like p′ among all the neighboring points in E, it means that point p is a non-edge point, and proceed to step 4 to judge the next point in M.

[0053] Step 8: Traverse all points in the point set M to obtain the edge point set of the visual field obstruction area, perform contour fitting, form the corresponding visual field obstruction area, and thus obtain the driver's unobstructed external visual field area. Figure 2 As shown in the figure, the traditional field of view occlusion contour line is extracted based on the entity boundary line. Figure 3 The midpoint horizontal line boundary is shown, and the visual field occlusion edge points and regions extracted by the method of the present invention are as follows Figure 3 The midpoint line is shown.

[0054] The helicopter cockpit external visual field analysis method of the present invention is applicable to visual field obstructions with various surface features, and can reproduce the visual field obstruction area quickly and with high precision.

[0055] The helicopter cockpit may be a parallel two-seat cockpit, a tandem two-seat cockpit, a single-row single-seat cockpit or other manned cockpit;

[0056] The shape of the field of vision obstruction is not limited, and the surface features can be a plane, a regular curved surface, an irregular curved surface, and various combinations thereof;

[0057] The search rolling circle radius may adopt an empirical fixed value or an adaptive radius with a fixed number of neighboring points.

[0058] The contour fitting method of the visual field occlusion area can be least squares fitting, weighted regression fitting, spline fitting or other arbitrary curve fitting.

[0059] The present invention proposes a method for analyzing the visual field outside the helicopter cockpit. First, the three-dimensional feature point set of the visual field obstruction object is completely converted into a two-dimensional visual field discrete point set, the edge point set of the visual field obstruction area is extracted, and the contour line is fitted to form the corresponding visual field obstruction area, so as to obtain the unobstructed external visual field area of ​​the driver. It is suitable for visual field obstructions with various surface features, and can quickly and accurately reproduce the visual field obstruction area, greatly improving the quality of the visual field assessment outside the helicopter cockpit. This method has been successfully applied to a certain type of helicopter and can be applied to other helicopters in the future, and has certain engineering application value.

Claims

1. A method for analyzing the visual field outside a helicopter cockpit, characterized in that: The following steps are involved: Step 1: Select the pilot's design eye position and give its three-dimensional point coordinates in the helicopter's full coordinate system, recorded as P0 (x0, y0, z0); Step 2: Select the field of view obstruction arranged in the whole aircraft coordinate system, and obtain the corresponding three-dimensional point set coordinates P of the field of view obstruction i (x i ,y i ,z i )(i=1,2,…n); Step 3: Design the eye position P0 based on the driver, and calculate the coordinates of each point P in the three-dimensional point set. i , obtain the corresponding two-dimensional field of view discrete points, and form a two-dimensional field of view discrete point set p i (u i ,ν i )(i=1,2,…n), denoted as M; Step 4: For any point p(u, ν) in the point set M, search for all points in M ​​whose Euclidean distance from point p(u, ν) is less than the preset distance, which is recorded as the point set E; Step 5: Select any point p′(u′,ν′) in the point set E, and calculate the coordinates p″(u″,ν″) and p″′(u″′,ν″′) of the center of the rolling circle passing through p and p′ with a radius of R; Step 6: Calculate the distances from other points in the point set E except point p′ to p″ and p″′; If the distances from other points to point p″ or p″′ are all greater than the R value, point p(u,ν) is determined to be an edge point; Step 7: If the distances from other points to point p″ or p″′ are not all greater than the R value, traverse all points in the point set E and rotate them to point p′; Repeat steps 5 and 6. If point p(u, ν) is determined to be an edge point, stop judging this point and proceed to step 4 to judge the next point in M. If there is no point like p′ in all neighboring points in E, it means that point p(u, ν) is a non-edge point, and proceed to step 4 to judge the next point in M. Step 8: Traverse all points in the point set M, obtain the edge point set of the field of view occlusion area, perform contour fitting, form the corresponding field of view occlusion area, and thus obtain the driver's unobstructed external field of view area.

2. A helicopter cockpit external visual field analysis method according to claim 1, characterized in that: In step 3, for each point P in the three-dimensional point set coordinates i , obtain the corresponding two-dimensional field of view discrete points, and form a two-dimensional field of view discrete point set p i (u i ,ν i )(i=1,2,…n), specifically: Solve point P by formula (1) i The corresponding field of view azimuth μ i and the pitch angle ν i , get the two-dimensional field of view discrete point set p i (u i ,ν i )(i=1,2,…n), denoted as M; 3. The method for analyzing the visual field outside a helicopter cockpit according to claim 1, characterized in that: In step 4, the preset distance is 2R , where R is the given search rolling circle radius.

4. The method for analyzing the visual field outside a helicopter cockpit according to claim 1, characterized in that: In step 5, the coordinates p″(u″, ν″) and p″′(u″′, ν″′) of the center of the rolling circle passing through p and p′ and having a radius of R are calculated as follows: Where: Intermediate variable H 5. The method for analyzing the visual field outside a helicopter cockpit according to claim 1, characterized in that: The helicopter cockpit is a parallel double-seat cockpit, a tandem double-seat cockpit or a single-row single-seat cockpit.

6. The method for analyzing the visual field outside a helicopter cockpit according to claim 1, characterized in that: The surface feature of the field of view blocking object is a plane, a regular curved surface, an irregular curved surface, or any combination of a plane, a regular curved surface, and an irregular curved surface.

7. The method for analyzing the visual field outside a helicopter cockpit according to claim 3, characterized in that: The search rolling circle radius adopts an empirical fixed value, or an adaptive radius with a fixed number of neighboring points.

8. The method for analyzing the visual field outside a helicopter cockpit according to claim 1, characterized in that: The contour line fitting method of the visual field occlusion area is least squares fitting, weighted regression fitting or spline fitting.

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