A method for evaluating visual function of flight personnel

Abstract

The invention discloses a method for evaluating the visual function of flight personnel, in the field of data flight simulation technology, according to the fineness calculation model of the constructed composite aerodynamic data and power propulsion data, the flight state of the aircraft is calculated, the flight environment influencing factors are added, the coordinate data of the x-axis, y-axis and z-axis of the aircraft in the virtual scene are recorded, the coordinate data of the aircraft in the x-axis, y-axis and z-axis are located to form a data list, and a flight trajectory model is formed in three-dimensional space, the position of the aircraft in the virtual scene is determined, and a continuous real-time flight trajectory number is formed, different weather scenes are selected, the visual function of the pilot in multiple scenes or multiple weathers in different environments is simulated, the visual function simulation result is obtained, the visual function simulation result is compared with the result collected after the real simulation, and the visual function of the pilot is evaluated. The method can accurately obtain the flight position information in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of flight simulation, and more specifically to a real-time evaluation method for visual function of flight personnel based on VR technology. Background Art

[0002] Virtual Reality (VR) is a computer simulation system that can create and experience a virtual world. It uses computers to generate a simulated environment to immerse users in the environment. By using VR headsets to conduct multiple flight trainings, and separate tests at the completion of each training flight and during visual function recovery training, different visual function data can be obtained, and then compared and combined with the flight trajectory data in flight training, so as to accurately obtain the visual data of the flight personnel, which helps to improve the accuracy of the assessment and better guide the flight personnel to conduct targeted training. However, this solution requires multiple people to cooperate in the test, which increases the training time and slows down the training efficiency.

[0003] The visual function training platform based on VR technology can simulate various actual flight operations to help pilots better adapt to different flight conditions. Existing flight simulations mainly use existing flight simulation plug-ins. In order to adapt to all aircraft models, this plug-in will unify and slow down the aircraft functions. In actual simulations, pilots will have the illusion of slow flight and the operation is not suitable for the aircraft model they operate. In order to train pilots to overcome this illusion and operational discomfort, pilots need to make multiple adjustments through testing to obtain more necessary flight data support, which increases development time and the number of bug fixes.

[0004] By analyzing the flight trajectory data of a large number of pilots, a research basis can be provided for the detection and recovery of the visual function of pilots. Existing flight simulation technology does not have the function of recording the flight trajectory. If you want to confirm the flight trajectory, you can only use video playback, which lacks accuracy. To obtain accurate axial positioning, it takes up a part of the equipment's computing power and has further requirements for hardware and software optimization.

[0005] Unreal Engine (UE) is a well-known licensed development engine developed by Epic, and UE5 is the fifth generation of the Unreal Engine. According to research by medical experts, after returning from flight missions, when the flight crews observe the vision of the flight crews in different flight environments based on VR technology, the impact of the environment on the eyes, and the scientific flight simulations for later recording and recovery will all cause discomfort and weakening of vision to varying degrees. This situation is difficult to detect immediately after the flight mission without medical personnel to detect it. When it is delayed until the physical examination, it will be found that the flight crews have different degrees of changes in vision, and there is no clear triggering point as a basis for treatment or prevention. There is no targeted way to prevent it in advance. It is necessary to communicate with ophthalmologists and collect data, and then combine medical research documents with UE5 scenes and visual rendering algorithms to achieve the expected results. After completion, multiple tests are required; scientific research indicators such as eye structure examination, color vision test, visual field examination, eye movement examination, etc., so as to ensure the accuracy of testing and data collection. However, there are relative differences between the visual observation methods based on VR technology and UE5, and the research report cannot be fully adopted, and it needs to be modified based on facts.

[0006] Since the flight process involves multiple scenes and the flight scenes cover a very large range, it is necessary to take into account the smoothness of the picture and operation when switching between different scenes in a large range of scenes. When simulating the impact of the sense of speed on visual function, the aircraft needs to fly in the scene at a very fast speed.

[0007] In summary, in the prior art, due to the excessively large scene simulation and the high-speed flying of the aircraft, a lot of calculations will be taken up when switching between different scenes, resulting in image delays and freezes. Such delays and freezes affect flight operations. High-speed flight will cause discomfort to the pilot, and ultimately make the acquired flight position positioning inaccurate, affecting the visual function assessment of the flight personnel. Summary of the invention

[0008] In response to the problems existing in the above-mentioned fields, the present invention proposes a method for evaluating the visual function of flight personnel, which can solve the technical problems that excessive scene simulation and high-speed flying aircraft will take up a lot of calculations when switching between different scenes, causing screen delays and freezes. Such delays and freezes affect flight operations, and high-speed flight will cause pilots to feel uncomfortable, ultimately resulting in inaccurate flight position positioning.

[0009] In order to solve the above technical problems, the present invention discloses a method for evaluating the visual function of flight personnel, comprising the following steps:

[0010] Simulate the pilot's flight under different environmental conditions to obtain simulated aerodynamic data and power system data;

[0011] Based on the simulated aerodynamic data and power system data, a sophisticated calculation model of composite aerodynamic data and power propulsion data is constructed;

[0012] The flight state of the aircraft is calculated according to the fine calculation model of the composite aerodynamic data and the propulsion data; according to the flight state of the aircraft, the flight environment influencing factors are added, and the coordinate data of the aircraft on the x-axis, y-axis and z-axis in the virtual scene are recorded, the coordinate data of the aircraft on the x-axis, y-axis and z-axis are located to form a data list, and a flight trajectory model is formed in the three-dimensional space to determine the position of the aircraft in the virtual scene;

[0013] According to the position of the aircraft in the virtual scene, a continuous number of real-time flight trajectories is formed; through the real-time flight trajectory number, different weather scenes are selected to simulate the visual function of the pilot in various scenes or various weather conditions in different environments, and obtain the visual function simulation results;

[0014] The simulated results of visual function are compared with the actual results, and the pilot's visual function is evaluated by analyzing the optical quality evaluation indicators.

[0015] Preferably, the simulation of the pilot's flight under different environmental conditions includes flight control simulation, scene simulation, climate simulation and time simulation, wherein:

[0016] Flight control simulation includes takeoff, climb, turn, level flight, descent and landing; simulated takeoff, the pilot controls the takeoff process of the aircraft and configures the parameters required for takeoff, including throttle control and flight speed; simulated climb, after completing the takeoff phase, the pilot needs to guide the aircraft to the predetermined flight altitude, and needs to control the speed, angle and height of the aircraft; simulated turn, the pilot controls the flight control system including the rudder to perform steering operations on the aircraft; simulated level flight, the pilot needs to maintain the stable flight of the aircraft at the specified altitude and speed; simulated descent, the pilot needs to control the descent angle, speed and attitude of the aircraft; simulated landing, the pilot practices how to align with the runway, control speed and altitude, and a wingman appears during the flight, flying in a fixed attitude and adjusting the flight speed according to the current flight status;

[0017] The scene simulation includes mountains, plains, snowy mountains and oceans. In mountain scenes, there is no airport setting. In plain scenes, an airport is set up, including airport buildings for takeoff and landing. In snowy mountain scenes, no airport is set up. In ocean scenes, ships in the ocean are used as reference objects.

[0018] Climate simulations include sunny, overcast, cloudy, and foggy days;

[0019] Time simulation: different lighting conditions at different times of the day have a great impact on the pilot's spatial perception; strong light during the day can temporarily blind the pilot; during night flights, the pilot needs to rely on instruments to fly; at dusk, the light changes rapidly, which places higher demands on the pilot's adaptability and concentration. In particular, in plain scenes, there are airport take-off and landing missions, and the airport lights serve as a guide.

[0020] Preferably, the obtaining of simulated aerodynamic data and power system data comprises the following steps:

[0021] Through the multi-light source simulation rendering function of Unreal Engine UE5, parallel light and point light are mixed and rendered, and exponential fog and particle cloud are superimposed to further refract or scatter the light source;

[0022] After simulating the complex light source of the real environment, the reflection field box is superimposed again to further increase the complexity of the light source direction in the environment;

[0023] A numerical modification interface is left in the scene so that the pilot can be invited to collect environmental data and make corrections.

[0024] Preferably, the construction of a sophisticated calculation model for composite aerodynamic data and power propulsion data comprises the following steps:

[0025] Use high-definition textures to simulate the 3D model of the aircraft. Based on Maya, combined with the sculpting software ZBrush, increase the precision of the high-polygon, multi-detailed fine sculpting components and models made through the sculpting mode, and build a fine calculation model for composite aerodynamic data and power propulsion data;

[0026] The fine-grained calculation model of the constructed composite aerodynamic data and propulsion data is imported into Maya for modeling operations. The details on the high-precision model are expanded into a normal map or height map through a ring light source to simulate the pilot switching between the cockpit environment and the in-flight path environment during a flight mission.

[0027] Preferably, the flight state of the calculated aircraft is obtained by calculating the aerodynamic data and the power system data through the physical code formula data of gravity, drag and lift.

[0028] Preferably, the formation of the flight trajectory model comprises the following steps:

[0029] The flight data is recorded at intervals of every milliseconds, and the x-axis, y-axis, and z-axis coordinate data of the aircraft are located to form a data list. The flight trajectory model is formed in the three-dimensional space by marking the positions of the located coordinate data in the three-dimensional space and connecting all the marked positions to form a three-dimensional route model with a direction of travel.

[0030] Preferably, the continuous real-time flight trajectory number is formed by continuously locating the position of the aircraft in each frame.

[0031] Preferably, the obtaining of the visual function simulation result comprises the following steps:

[0032] Through real-time flight trajectory data, virtual reality technology is used to simulate the pilot's visual functions in multiple scenarios or under various weather conditions in different environments.

[0033] Preferably, the acquisition of the true result comprises the following steps:

[0034] The map is constructed using satellite elevation maps, height maps, and high-definition satellite photos to restore the near and far views of the pilots during flight and to repeatedly stimulate the visual function.

[0035] Use particle clouds, exponential fog, ambient light, and shadow rendering in the air to simulate all the movements of an aircraft flight, build a simulation process close to the real-world environment, and obtain real results in multiple scenes or multiple weather and time in the environment.

[0036] Preferably, the optical quality evaluation index includes high-order aberrations, low-order aberrations, contrast sensitivity, point spread function, accommodation power and diopter, wherein:

[0037] The low-order aberrations include myopia, hyperopia and astigmatism;

[0038] The high-order aberrations include spherical aberration, coma and irregular astigmatism;

[0039] The contrast sensitivity is the reciprocal of the contrast threshold that the visual system can perceive, that is, contrast sensitivity = 1 / contrast threshold; the lower the contrast threshold, the higher the contrast sensitivity, indicating that the visual function is good. At a certain spatial frequency, the visual system has a certain contrast sensitivity; conversely, at the same contrast, the visual system has a certain spatial frequency resolution;

[0040] The point spread function is the light intensity distribution of a point-shaped object in retinal imaging; the smaller the spot area formed by the point spread function, the better the retinal imaging quality;

[0041] The accommodation power and the diopter are obtained through optometry.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The evaluation method proposed in the present invention can overcome the technical defects in the prior art that due to the large scene simulation and the high-speed flying aircraft, a lot of calculations will be taken up when switching different scenes, resulting in screen delay and jamming. This delay and jamming affect the flight operation, and the high-speed flight will cause the pilot to feel uncomfortable, and finally make the acquired flight position positioning inaccurate, thereby affecting the visual function evaluation of the flight personnel. The method obtains the aerodynamic data and power system data of the flight simulation, constructs a precision calculation model of composite aerodynamic data and power propulsion data, obtains the pilot switching cockpit environment and mid-flight environment during the flight mission, and provides data support for accurately obtaining the position information of the aircraft. The flight state of the aircraft is calculated according to the constructed precision calculation model, and the coordinate data of the x-axis, y-axis and z-axis of the aircraft in the virtual scene are formed into a data list and recorded, and a flight trajectory model is formed in three-dimensional space, and the cockpit scene is generated for the pilot, and the geometric shape, relative position and motion relationship of various entities in the scene are described, so that the position of the aircraft in the virtual scene can be accurately determined. By reading the flight parameter record data and simulating the real-time flight trajectory in different simulation environments, the process and flight parameter data are displayed in real time in the form of a realistic three-dimensional space motion trajectory model. The simulation results are closer to reality, and the simulation results are compared and analyzed with the real results, making the obtained evaluation results more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the overall evaluation method of the present invention;

[0045] Figure 2 A schematic diagram of the environmental impact added for the present invention;

[0046] Figure 3 It is a schematic diagram of the visual simulation process of the present invention;

[0047] Figure 4 The present invention uses real-time measurement results of wavefront aberration inspection;

[0048] Figure 5 A schematic diagram of the frequency in the visual simulation of the present invention;

[0049] Figure 6 It is a schematic diagram of collecting accommodation power and refractive power in the visual simulation of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the attached embodiment of the present invention Figure 1-Figure 6 , the technical solutions in the embodiments of the present invention are clearly and completely described. It should be understood that the terms described in the present invention are only used to describe specific implementation methods and are not used to limit the present invention.

[0051] Example

[0052] like Figure 1 As shown, an embodiment of the present invention provides a method for evaluating the visual function of flight personnel, comprising the following steps:

[0053] S1: Simulate the pilot's flight under different environmental conditions to obtain simulated aerodynamic data and power system data;

[0054] S2: Based on the simulated aerodynamic data and power system data, a sophisticated calculation model of composite aerodynamic data and power propulsion data is constructed;

[0055] S3: Calculate the flight state of the aircraft according to the fine calculation model of the composite aerodynamic data and propulsion data; Add the flight environment influencing factors according to the flight state of the aircraft, record the coordinate data of the x-axis, y-axis and z-axis of the aircraft in the virtual scene, locate the coordinate data of the x-axis, y-axis and z-axis of the aircraft to form a data list, and form a flight trajectory model in three-dimensional space to determine the position of the aircraft in the virtual scene;

[0056] S4: according to the position of the aircraft in the virtual scene, a continuous number of real-time flight trajectories is formed; through the real-time flight trajectory number, different weather scenes are selected to simulate the visual function of the pilot in multiple scenes or multiple weather conditions in different environments, and obtain the visual function simulation result;

[0057] S5: Compare the simulated visual function results with the actual results, and evaluate the pilot's visual function by analyzing the optical quality evaluation indicators.

[0058] In step S1, different environmental states include the following:

[0059] 1) Flight control simulation, including take-off, climb, turn, level flight, descent and landing.

[0060] Simulated takeoff: In a virtual environment, the pilot controls the aircraft's takeoff process and reasonably configures the various parameters required for takeoff, such as throttle control and flight speed.

[0061] Simulated climb: After completing the takeoff phase, the pilot needs to guide the aircraft to a predetermined flight altitude. The pilot needs to control the aircraft's speed, angle, altitude and other parameters so that the aircraft can climb steadily to the specified altitude.

[0062] Simulated steering: In a virtual environment, the pilot can perform steering operations on the aircraft by controlling the rudder and other flight control systems. The aircraft's body attitude and flight direction are coordinated to ensure that the aircraft remains stable during the steering process.

[0063] Simulated level flight: Level flight is a state in which the aircraft maintains a stable flight. The pilot maintains the stable flight of the aircraft at a specified altitude and speed and masters the flying skills and flight management skills required for level flight.

[0064] Simulated descent: In a virtual environment, the pilot gradually lowers the flight altitude in preparation for landing. The pilot needs to control the aircraft's descent angle, speed, and attitude to ensure that the aircraft can land safely and smoothly.

[0065] Simulated landing: In virtual reality training, pilots practice basic landing skills and procedures to improve their landing capabilities. This includes mastering how to align with the runway, control speed and altitude, etc. Through repeated training, pilots can gradually master the key elements of landing and improve accuracy and stability in actual operations. During the flight, a wingman appears, flies in a fixed attitude, and adjusts the flight speed and fixes the direction according to the current user's flight status.

[0066] 2) Multiple scenes, including mountains, plains, snowy mountains and oceans.

[0067] Mountain scene: Low altitude mountainous terrain is complex and high in altitude. Low altitude flight reference objects are relatively obvious, and there is no airport setting.

[0068] Plain scene: The terrain in the plain area is relatively flat, with lower requirements for flight operations and simpler visual references. An airport is set up, including airport buildings, which are mainly used for takeoff and landing.

[0069] Snowy mountain scene: The snowy mountain environment is harsh, the field of vision is limited, the ground signs are not obvious, the reflection under light is serious, there are many reference objects, and there is no airport.

[0070] Ocean scene: simulates ocean scenes, including ocean reflections when illuminated, and ships in the ocean as reference objects.

[0071] Weather conditions have a significant impact on flight. The weather scenes are mainly set to 4 types of climate, including sunny, cloudy, cloudy and foggy. Sunny days have good visibility and no clouds; cloudy days have good visibility and more clouds, and simulated flight can penetrate thick clouds; cloudy days have low visibility; foggy days have extremely poor visibility and are prone to flight illusions. The four types of weather scenes can be set as fixed climates or set to switch automatically and randomly over time.

[0072] Time of day scenes include dusk (dawn), daytime, and night. Different lighting conditions at different times have a great impact on the pilot's spatial perception. Strong light during the day may cause temporary blindness to the pilot; during night flights, visibility is reduced and the pilot needs to rely on instruments to fly; at dusk, the light changes rapidly, which places higher demands on the pilot's adaptability and concentration. In plain scenes, because there are airport take-off and landing missions, the lights at the airport can be used as a guide.

[0073] Because various scenes are developed with separate scene maps and special effects, switching needs to be done through the system's UI main interface.

[0074] 3) Record flight trajectory and completion time module

[0075] The flight record parameters include flight time, flight coordinate trajectory and flight speed.

[0076] Flight time: timestamp of the current flight time, flight completion time, etc. You can set the absolute time or the current simulation time.

[0077] Flight coordinate trajectory: coordinate data of the x-axis, y-axis and z-axis.

[0078] Flight speed: record the flight speed data at each time.

[0079] The above data can eventually be exported through the system background to generate a data table.

[0080] 4) Visual quality improvements for builds using VR

[0081] Use the VR simulation experience function to create a visual experience animation scene that simulates the focusing function of the human eye, and adjust the focus of the picture repeatedly. The position of the subject in the picture cannot be moved, but the viewing angle can be adjusted freely.

[0082] Due to the freedom characteristics of VR, it is impossible to determine the visual point of the subject's focus through the VR device, so a three-dimensional natural scenery animation with a fixed perspective alternating between near and far is made to guide the subjects to watch. The animation time does not exceed 30 seconds.

[0083] Flight simulation technology mainly provides pilots in training with realistic flight control force and flight status changes. Pilots judge the flight status and perform corresponding operations based on the changes in control force.

[0084] Force simulation fidelity is an important criterion for evaluating the level of flight simulation, requiring the control load system to have good simulation fidelity for static and dynamic control force. The control load system of the flight simulator is divided into two parts: the main control load system and the auxiliary control load system: the main control load system is used to simulate the lateral and longitudinal control stick forces and pedal forces and generate rudder deflection angle signals, and the force fidelity requirements are relatively high; the auxiliary control load system is used to simulate the control force of the throttle lever, front wheel turning, brake and other control systems, and the force simulation fidelity requirements are low.

[0085] The flight simulator instrument system provides the pilot with information such as the aircraft's altitude, airspeed, vertical speed, heading and attitude, creating an instrument environment for the pilot that is the same as a real aircraft, thereby simulating the aircraft's flight environment in conjunction with the visual simulation system. The pilot uses the instrument system to dispatch air-to-ground traffic.

[0086] The military pilot psychological stress training system based on virtual reality technology is a combination of 3D modeling and virtual reality VR technology. The main development language used is C++, and the development software for scene applications and interactive systems is UE5. With professional equipment and the application of the UE5 development system, the desired immersive experience of aviation flight can be fully realized.

[0087] Build a scene to create a visual, interactive, script-driven virtual reality environment.

[0088] Stereoscopic rendering uses two cameras to render the scene, representing the user's left and right eyes respectively. Through the lens of the head display, the two images are overlapped to form a clear scene with depth vision. Real-time rendering is achieved through UE5, which is used to quickly build VR content flight simulation scenes and interactive processes.

[0089] Head tracking changes the position and rotation of the camera in the virtual world by capturing the position and rotation of the headset.

[0090] Polarized 3D imaging is to send two images with different polarization states to both eyes, and each eye is only allowed to see one of them. Using UE5 to create 3D virtual reality content means creating these two images and projecting them to both eyes.

[0091] Visual simulation technology, mainly composed of a visual generation system and a display system, generates a view outside the cockpit for the pilot, describing the geometric shapes, relative positions and motion relationships of various entities in the scene. The visual display is mainly a virtual reality helmet display, which can achieve a more realistic immersive feeling.

[0092] The present invention requires a large amount of model construction for visual simulation. For flight simulators, large terrain modeling and scene construction are crucial. Simulation environment production includes model design, scene construction, texture design and production, special effect design, etc.

[0093] Visual simulation requires the construction of environmental special effects. It is essential to build weather, waves, ships, and weapon launch contrails in a virtual battlefield environment. For example, weather effects can be constructed through particle special effects technology, clouds of various shapes and properties can be constructed using volumetric cloud technology, and rivers, lakes, etc. can be constructed using fluid technology.

[0094] Flying motion collision technology, because the efficiency of the collision detection algorithm directly affects the real-time performance of various applications, especially in large scenes. Since there are many objects and moving objects in the surrounding scenes, it is necessary to repeatedly perform collision detection between a large number of objects. Fast collision detection algorithm is a very important key technology to realize this application.

[0095] Since there are bound to be collision problems in actual aircraft flights, it is inevitable to add collision detection functions in virtual reality simulation systems to avoid abnormal situations such as aircraft flying through terrain in virtual environments, making the virtual reality system more realistic.

[0096] Flight simulation review technology, after the simulated air team completes the task, the system records the real-time flight data of each unit and displays it in two-dimensional and three-dimensional forms. During the simulation process, the numerical visualization simulation module generates aircraft motion data, simulates the real-time flight trajectory in the simulation environment by reading the flight parameter record data, and displays the process, flight parameter data, etc. in real time in the form of a realistic three-dimensional space motion trajectory model.

[0097] While satisfying the test personnel's flight under different environmental conditions, it can also cause visual impacts close to the real environment on the test personnel's eyes. It can also meet the evaluation and comparison of the pilot's visual quality under simulated eye conditions, so as to better collect optical quality evaluation indicators such as high-order aberrations, low-order aberrations, contrast sensitivity, intraocular scattering index, accommodation power, and refractive power.

[0098] The specific implementation is based on the multi-light source simulation rendering function of UE5, using parallel light and point light mixed rendering, and superimposing exponential fog and particle cloud to further refract or scatter the light source. After simulating the complex light source of the real environment, the reflection field box is superimposed again to further increase the complexity of the light source direction in the environment. A numerical modification interface is left in the scene to facilitate correction after inviting pilots to collect environmental data.

[0099] In step S2, realistic high-precision modeling

[0100] To further achieve a more realistic test environment, the simulation of the 3D models in the scene uses high-definition textures to complete the main 3D models, including: aircraft, cockpit, buildings and other main contents. The aircraft model realizes the movable wings, tail, landing gear and other parts to improve the authenticity of the fighter. The cockpit provides synchronous movement of the joystick, and provides interface backlight, screen display, cockpit lights and other contents. While increasing the authenticity of the tester's experience, it simulates that the pilot will often switch between the cockpit environment and the in-flight environment during the flight mission, such as looking at the real screen, turning on the fighter panel backlight, turning on the cockpit lights, etc.

[0101] In order to construct a high-precision calculation model for composite aerodynamic data and power propulsion data, Maya is used as the basis for modeling and combined with the sculpting software ZBrush to increase the precision of high-polygon, multi-detailed fine sculpting components and models made through the sculpting mode. After the modeling is completed, it is combined into a high-precision model and imported into Maya for modeling operations. The details on the high-precision model are expanded into a normal map or height map through a ring light source, that is, the precision of the high-precision model is achieved and a low-polygon model can be used to ensure the smoothness of the software's operations, and the computing power is not occupied by too many high-precision models.

[0102] The fighter immersive operation simulation in step S3

[0103] In order to make the flight of the aircraft in VR closer to reality, the present invention realizes the simulated flight feel of the aircraft through physical formula data codes. The aircraft has flight functions such as take-off, left tilt, right tilt, climb, dive, glide, and land, and has simulated aerodynamic data and power system data for the physical formula data code to calculate the flight status of the aircraft and record it. By recording the coordinate data of the x-axis, y-axis, and z-axis of the aircraft in the virtual scene, the position of the aircraft in the virtual scene is determined, and the position of the aircraft is continuously located in each frame to form a continuous flight trajectory number.

[0104] In step S4, the environment visual simulation

[0105] In order to achieve a higher level of environmental simulation, satellite map elevation maps, height maps, high-definition satellite photos and other content were used to build the map when building the entire environment. In addition, environmental modules such as particle clouds, exponential fog, ambient light, and shadow rendering were used in the air to achieve multiple scenes or multiple weather and time effects in the environment.

[0106] The evaluation method proposed in the present invention is a real-time evaluation and improvement training platform for the visual function of flight personnel built based on VR technology, which will provide an effective training platform for studying the evaluation indicators, influencing factors and improvement measures of the visual function of flight personnel. Through virtual reality simulation of multi-environment and multi-weather training, eye evaluation and recovery training and flight data recording are carried out. Multiple virtual scenes and weather environments are provided for scientific research, and the visual function is evaluated through simulated training of pilots. The evaluation system has a simulated controllable aircraft, a simulated aircraft cockpit and a control panel. The control panel has interactive functions such as backlight, lighting, and display, including functions such as turning on backlight display switching. After flight training, a complete data record of the flight personnel's operations can be made. The record will adopt a multi-axial recording method of x-axis, y-axis and z-axis, which can fully present the pilot's flight trajectory data in three-dimensional space.

[0107] In terms of scenes, satellite images of real scenes are used in combination with building models to restore the realism of the near and far views of the pilots during flight and repeatedly stimulate their visual functions. The scenes also have multiple modes (plains, snow, rainy days, etc.) to provide a variety of complex environments and lighting conditions to simulate which environment can have a positive or negative impact on the pilot's visual function.

[0108] The platform needs to simulate a completely realistic sense of flight control. The aircraft will simulate all flight actions through air physics data, and can perform simulated operations such as takeoff, landing, and long-term flight. The flight scene needs to be close to the real world environment and is fully simulated, such as the spacing of street lights, the slope of the coastline, and the traversability of buildings.

[0109] At the end of the training, the pilot will be switched to a comfortable virtual environment, such as a sunny forest or a mountain environment with blue sky. By repeatedly switching between near and far scenes, the pilot can relax his visual function and restore his visual function.

[0110] The real-time evaluation method and improvement training platform of the visual function of flight personnel built based on VR technology through the above functions can provide a multi-index detection platform for visual quality before and after visual function for research topics, confirm the correlation between the core parameters of the visual function of flight personnel and flight control and environment. At the same time, it can verify the degree of recovery of the pilot's visual function in a better environment.

[0111] Wavefront aberration test is an objective test method that objectively reflects whether there is a difference in refractive power in the pupil area. It is also a method used to evaluate visual quality. It is divided into low-order aberrations and high-order aberrations. Low-order aberrations include myopia, hyperopia and astigmatism, and high-order aberrations include spherical aberration, coma and irregular astigmatism. Wavefront aberration can be measured in real time by OPD-Scan III, such as Figure 4 shown.

[0112] Contrast sensitivity refers to a kind of resolution ability, which is defined as the inverse of the contrast threshold that the visual system can perceive, that is, contrast sensitivity = 1 / contrast threshold. The lower the contrast threshold, the higher the contrast sensitivity and the better the visual function. At a certain spatial frequency, the visual system has a certain contrast sensitivity; conversely, at the same contrast, the visual system has a certain spatial frequency resolution.

[0113] The visual quality function is an indicator for objectively evaluating the visual quality of the eye, including the point spread function (PSF) and the modulation transfer function (MTF). In optometry, PSF refers to the light intensity distribution function of an object point on the image plane after passing through the optical system, and the PSF of the eye refers to the light intensity distribution of a point-shaped object on the retinal image. Since any object can be considered to be composed of countless point light sources, the imaging characteristics can be understood more intuitively through the image of the PSF. It is generally believed that the smaller the spot area formed by the PSF, the better the retinal imaging quality. The greater the light intensity of the spot, the less light energy loss after the point light source passes through the optical system, and the better the retinal imaging quality. In optometry, graphical methods are often used to represent MTF. Strictly speaking, MTF is a surface whose x-axis and y-axis represent the spatial frequency f in the x-direction, respectively. x and the spatial frequency f in the y direction y , the z-axis represents the ratio of the modulation degree after passing through the system to that before passing through the system, i.e., the MTF value. Therefore, it can be seen that the maximum value of the z-axis is 1, such as Figure 5 shown.

[0114] From Fourier optics, we know that any object can be regarded as a superposition of a series of sinusoidal fringes with different spatial frequencies, phases, and directions. Therefore, the optical transfer function can be used to study the imaging performance of the visual system.

[0115] The modulation transfer function (MTF) is the main optical transfer function. The MTF value of the eye is mainly affected by factors such as pupil diameter, diffraction and human eye aberration. When there is no aberration, the human eye is a diffraction-limited system, and its MTF is only affected by the pupil diameter. The larger the pupil diameter, the smaller the diffraction effect and the higher the MTF value. The human eye has aberrations at large pupils. When aberrations exist, the effect of aberrations on MTF is more obvious. The larger the pupil diameter, the greater the aberration of the human eye and the lower the MTF value.

[0116] Different degrees of refractive error, that is, low-order aberrations, also have a significant impact on MTF. In the practice of optometry, the x-axis of the MTF curve represents the spatial frequency, and the y-axis represents the MTF value. For normal human eyes, MTF shows a downward trend as the spatial frequency increases, and its curve gradually decreases from low spatial frequency to high spatial frequency to 0, intersecting the horizontal axis, where the corresponding frequency is the cutoff frequency.

[0117] The visual quality function of the eye can also be measured in real time by OPD-Scan III. The accommodation power and refraction can be obtained by optometry. The acquisition of accommodation power and refraction is also integrated in OPD-Scan III, such as Figure 6 shown.

[0118] The present invention is a multi-scenario training platform developed based on flight simulation. At the same time, it combines virtual reality technology to customize the direction of eye simulation flight scenes, adopts a virtual reality simulation environment, develops multi-weather simulation scenes based on virtual reality technology, uses real aircraft, scenes and light, etc. to provide real vision and experience for auxiliary testing, and uses physical testing equipment to check changes in optical quality evaluation indicators such as vision and refraction before and after the simulated flight test.

[0119] The advantages of the real-time assessment method of flight personnel visual function and the improved training platform proposed by the present invention based on VR technology include the following:

[0120] 1. Low cost

[0121] In order to conduct multi-environment visual function assessment, the traditional training model requires pilots to fly frequently in real flight conditions to achieve the effect of data collection. However, frequent flights also increase the cost of data collection. The fuel consumption of each flight mission of the aircraft, the maintenance of the brake system engine after landing, and each flight consumes a lot of money.

[0122] The VR simulation system is different. It has a long service life and does not require maintenance. The VR simulation system can be used multiple times, and only one room is needed to place multiple sets of equipment. It no longer requires the cooperation of various airports. Compared with the cost of each flight, the cost of future flight training can be greatly reduced.

[0123] 2. Efficient and fast

[0124] In projects where the evaluation is conducted on content such as training, the inconvenience of actual flight training for pilots increases the time and efficiency of visual function evaluation. Each training process requires pilots to coordinate with airports in multiple places. Pilots have heavy flight tasks and it is impossible to fly with one data collection or visual evaluation. They are often tested after performing a flight mission, but each flight mission takes a long time. The factors affecting the visual function of pilots during flight are too complicated to determine. After the flight mission is completed, the impact on the visual function has been alleviated after landing, which greatly reduces the accuracy of the visual function evaluation.

[0125] However, using VR simulation training, there is no limitation of venue and time, which will save most of the time for deployment and waiting. VR equipment can be quickly removed as a computer external device. Pilots can quickly remove it during VR training and perform vision test, slit lamp examination, intraocular pressure measurement, optometry trial lens and fundus examination under slit lamp, etc. The timeliness of VR simulation training of the present invention is an advantage that real flight does not have, and repeatable observation is also not available in real flight.

[0126] 3. Low risk

[0127] Flight training itself has a certain degree of randomness. If pilots take off and land frequently or fly in different weather conditions, the difficulty and danger will increase exponentially. However, the training program requires pilots to keep flying under various unfavorable conditions, which increases the risk level of flight again. However, VR training can perfectly avoid this situation. The safety of VR equipment is beyond doubt, and it also increases the protection of pilot safety.

[0128] 4. Real-time data collection

[0129] VR training uses VR equipment to collect data in real time, which can be done by preparing detection equipment in advance or integrating the collection equipment into the VR equipment. It has the advantages of close distance, real-time and interruptibility.

[0130] 5. The flight can be interrupted and restarted

[0131] As VR training, it is necessary to interrupt and restart during flight to change the direction of visual function detection. For example, backlight, scene switching, time or weather change, which is impossible to do in real-time flight missions. However, in VR training, the present invention builds a real world in Unreal 5 and can also be controlled. Only a small blueprint is needed to make various modifications to this real world to achieve visual function detection or improvement training.

[0132] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0133] In addition, unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention belongs. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods related to the documents. In the event of any conflict with any incorporated document, the content of this specification shall prevail.

Claims

1. A method for evaluating the visual function of flight personnel, characterized in that: The following steps are involved: Simulate the pilot's flight under different environmental conditions to obtain simulated aerodynamic data and power system data; Based on the simulated aerodynamic data and power system data, a sophisticated calculation model of composite aerodynamic data and power propulsion data is constructed; The flight state of the aircraft is calculated according to the fine calculation model of the composite aerodynamic data and the propulsion data; according to the flight state of the aircraft, the flight environment influencing factors are added, and the coordinate data of the aircraft on the x-axis, y-axis and z-axis in the virtual scene are recorded, the coordinate data of the aircraft on the x-axis, y-axis and z-axis are located to form a data list, and a flight trajectory model is formed in the three-dimensional space to determine the position of the aircraft in the virtual scene; According to the position of the aircraft in the virtual scene, a continuous number of real-time flight trajectories is formed; through the real-time flight trajectory number, different weather scenes are selected to simulate the visual function of the pilot in various scenes or various weather conditions in different environments, and obtain the visual function simulation results; The simulated results of visual function are compared with the actual results, and the pilot's visual function is evaluated by analyzing the optical quality evaluation indicators.

2. The method for evaluating the visual function of flight personnel according to claim 1, characterized in that: The simulation of the pilot's flight under different environmental conditions includes flight control simulation, scene simulation, climate simulation and time simulation, wherein: Flight control simulation includes takeoff, climb, turn, level flight, descent and landing; simulated takeoff, the pilot controls the takeoff process of the aircraft and configures the parameters required for takeoff, including throttle control and flight speed; simulated climb, after completing the takeoff phase, the pilot needs to guide the aircraft to the predetermined flight altitude, and needs to control the speed, angle and height of the aircraft; simulated turn, the pilot controls the flight control system including the rudder to perform steering operations on the aircraft; simulated level flight, the pilot needs to maintain the stable flight of the aircraft at the specified altitude and speed; simulated descent, the pilot needs to control the descent angle, speed and attitude of the aircraft; simulated landing, the pilot practices how to align with the runway, control speed and altitude, and a wingman appears during the flight, flying in a fixed attitude and adjusting the flight speed according to the current flight status; The scene simulation includes mountains, plains, snowy mountains and oceans. In mountain scenes, there is no airport setting. In plain scenes, an airport is set up, including airport buildings for takeoff and landing. In snowy mountain scenes, no airport is set up. In ocean scenes, ships in the ocean are used as reference objects. Climate simulations include sunny, overcast, cloudy, and foggy days; Time simulation: different lighting conditions at different times of the day have a great impact on the pilot's spatial perception; strong light during the day can temporarily blind the pilot; during night flights, the pilot needs to rely on instruments to fly; at dusk, the light changes rapidly, which places higher demands on the pilot's adaptability and concentration. In particular, in plain scenes, there are airport take-off and landing missions, and the airport lights serve as a guide.

3. The method for evaluating the visual function of flight personnel according to claim 2, characterized in that: The step of obtaining simulated aerodynamic data and power system data comprises the following steps: Through the multi-light source simulation rendering function of Unreal Engine UE5, parallel light and point light are mixed and rendered, and exponential fog and particle cloud are superimposed to further refract or scatter the light source; After simulating the complex light source of the real environment, the reflection field box is superimposed again to further increase the complexity of the light source direction in the environment; A numerical modification interface is left in the scene so that the pilot can be invited to collect environmental data and make corrections.

4. The method for evaluating the visual function of flight personnel according to claim 3, characterized in that: The method of constructing a precision calculation model for composite aerodynamic data and power propulsion data comprises the following steps: Use high-definition textures to simulate the 3D model of the aircraft. Based on Maya, combined with the sculpting software ZBrush, increase the precision of the high-polygon, multi-detailed fine sculpting components and models made through the sculpting mode, and build a fine calculation model for composite aerodynamic data and power propulsion data; The fine-grained calculation model of the constructed composite aerodynamic data and propulsion data is imported into Maya for modeling operations. The details on the high-precision model are expanded into a normal map or height map through a ring light source to simulate the pilot switching between the cockpit environment and the in-flight path environment during a flight mission.

5. The method for evaluating the visual function of flight personnel according to claim 4, characterized in that: The flight state of the calculated aircraft is obtained by calculating the aerodynamic data and the power system data through the physical code formula data of gravity, drag and lift.

6. The method for evaluating the visual function of flight personnel according to claim 5, characterized in that: The formation of the flight trajectory model comprises the following steps: The flight data is recorded at intervals of every milliseconds, and the x-axis, y-axis, and z-axis coordinate data of the aircraft are located to form a data list. The flight trajectory model is formed in the three-dimensional space by marking the positions of the located coordinate data in the three-dimensional space and connecting all the marked positions to form a three-dimensional route model with a direction of travel.

7. The method for evaluating the visual function of flight personnel according to claim 6, characterized in that: The continuous real-time flight trajectory number is formed by continuously locating the aircraft position in each frame.

8. The method for evaluating the visual function of flight personnel according to claim 7, characterized in that: The method of obtaining the visual function simulation result comprises the following steps: Through real-time flight trajectory data, virtual reality technology is used to simulate the pilot's visual functions in multiple scenarios or various weather conditions in different environments.

9. The method for evaluating the visual function of flight personnel according to claim 8, characterized in that: The acquisition of the true result includes the following steps: The map is constructed using satellite elevation maps, height maps, and high-definition satellite photos to restore the near and far views of the pilots during the flight and to repeatedly stimulate the visual function. Use particle clouds, exponential fog, ambient light, and shadow rendering in the air to simulate all the movements of an aircraft flight, build a simulation process close to the real-world environment, and obtain real results in multiple scenes or multiple weather and time in the environment.

10. The method for evaluating the visual function of flight personnel according to claim 9, characterized in that: The optical quality evaluation indexes include high-order aberrations, low-order aberrations, contrast sensitivity, point spread function, accommodation power and diopter, wherein: The low-order aberrations include myopia, hyperopia and astigmatism; The high-order aberrations include spherical aberration, coma and irregular astigmatism; The contrast sensitivity is the reciprocal of the contrast threshold that the visual system can perceive, that is, contrast sensitivity = 1 / contrast threshold; the lower the contrast threshold, the higher the contrast sensitivity, indicating that the visual function is good. At a certain spatial frequency, the visual system has a certain contrast sensitivity; conversely, at the same contrast, the visual system has a certain spatial frequency resolution; The point spread function is the light intensity distribution of a point-shaped object when imaging the retina; the smaller the spot area formed by the point spread function, the better the retinal imaging quality; The accommodation power and the diopter are obtained through optometry.

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