A digital map-based helicopter terrain cueing and warning system

Abstract

This application discloses a helicopter terrain warning and alert system based on a digital map, relating to the field of helicopter flight safety technology. The system includes: a data acquisition and verification module for acquiring real-time helicopter navigation data via an onboard data bus, and performing validity verification and fusion processing on various data sources; a geographic information processing module for reading digital elevation model data and obstacle database from onboard storage devices, and generating a comprehensive situational awareness based on the helicopter's real-time position and altitude; a threat assessment and alert calculation module for establishing a forward prediction area based on the flight path and a vertical monitoring area based on the terrain directly below the helicopter, and performing threat judgment and alert level classification based on a safety margin model; and a multimodal alert output and interaction module for outputting alert information to the display and audio systems, and receiving alert suppression commands from the pilot to control the start and stop of alert output.

Description

Technical Field

[0001] This invention relates to the field of helicopter flight safety technology, and in particular to a helicopter terrain prompting and warning system based on digital maps. Background Technology

[0002] Controlled Flight Into-Earth (CFIT) refers to an aviation accident or incident in which an aircraft unintentionally collides with the ground, obstacle, or water while the pilot still has control over it. Helicopters, due to their unique flight characteristics, often need to perform low-altitude and ultra-low-altitude flight missions, especially in complex terrain areas such as mountains, cities, and canyons, for search and rescue, power line patrols, and law enforcement operations. Under these mission profiles, the risk of CFIT increases significantly: in plains or hilly areas, tall, isolated obstacles and inconspicuous power lines are the main threats to helicopter CFIT; while in mountainous or complex terrain areas, suddenly appearing steep terrain or hidden ridges and cliffs ahead of the flight path constitute another typical and deadly source of CFIT risk.

[0003] To address the threat of Flight Conflict Ingress (CFIT), aviation warning technologies are constantly evolving. Ground Proximity Warning Systems (GPWS) primarily rely on radio altimeters to measure the vertical distance between the aircraft and the terrain directly below, triggering voice and visual warnings in unsafe conditions such as excessively low altitude or excessive rate of descent. A key drawback of GPWS is its ability to detect terrain directly below or already flown over; it cannot provide effective warnings for terrain suddenly rising ahead of the flight path, posing a significant safety hazard of no warning or delayed warnings. To address the blind spot of GPWS, Enhanced Ground Proximity Warning Systems (EGPWS) integrate an onboard global terrain database, precise Global Positioning System (GPS), and the flight path prediction function of the flight management system. This enables predictive warnings of potential terrain conflicts ahead of the flight path and adds terrain situation display functionality, improving flight safety. However, the system is mainly designed and equipped on civil airliners and large transport aircraft that operate at high altitudes and high speeds. Its alarm logic, data update rate and display method are often difficult to meet the needs of helicopters in low-altitude, slow-speed, high-maneuverability flight and in operating environments with extremely high requirements for precision and real-time performance.

[0004] Currently, some advanced helicopters are equipped with navigation and display systems that integrate 3D enhanced vision or similar functions. These systems can generate 3D terrain backgrounds based on databases and may have some obstacle warning capabilities. However, these functions are usually positioned as context-aware assistance, and their warning thresholds, real-time computing capabilities, and fusion processing with non-cooperative obstacles still lag behind terrain warning and warning systems specifically designed for CFIT prevention that meet airworthiness requirements. In particular, while airborne collision avoidance radar, which helicopters often rely on, can actively detect obstacles ahead, its effective detection range is limited, especially in adverse weather conditions or when detecting thin, long cables. This results in a short warning window, leaving pilots very little time to perform evasive maneuvers, and the safety risks remain prominent. Summary of the Invention

[0005] This application provides a helicopter terrain warning and alert system based on digital maps, addressing the blind spot problem of traditional ground proximity warning systems and the limitations of enhanced ground proximity warning systems that do not match the special mission profiles of helicopters. By utilizing multi-dimensional data fusion and real-time dynamic modeling, a layered, color-coded 3D terrain situation image is generated based on the helicopter's real-time altitude, providing pilots with intuitive environmental perception. By establishing forward prediction and vertical monitoring areas, combined with a safety margin model, graded warnings are achieved for the collision risks of terrain ahead and directly below the flight path and obstacles.

[0006] This application provides a helicopter terrain prompting and warning system based on digital maps, including: The data acquisition and verification module is used to acquire the helicopter's navigation parameters, atmospheric data, and obstacle information detected by sensors in real time through the airborne data bus, and to perform validity verification and fusion processing on each data source. The geographic information processing module, connected to the data acquisition and verification module, is used to read digital elevation model data and obstacle database from the airborne storage device, and dynamically generate a comprehensive situational image that includes a layered colored terrain background and superimposed obstacle symbols based on the helicopter's real-time position and altitude. The threat assessment and alarm calculation module is connected to the data acquisition and verification module and the geographic information processing module, respectively. It is used to establish a forward prediction area based on the flight path and a vertical monitoring area based on the terrain directly below the helicopter. By integrating real-time terrain profiles, obstacle information and flight status, it performs threat judgment and alarm level classification based on the safety margin model. The multimodal alarm output and interaction module, connected to the threat assessment and alarm calculation module, is used to output alarm information to the cockpit display and audio system in the form of synchronized visual highlighting, text prompts and graded voice, and to receive alarm suppression commands from the pilot to control the start and stop of alarm output.

[0007] Furthermore, the data acquisition and verification module includes: The navigation data interface unit is used by the helicopter to obtain its position, altitude, ground speed, heading, and track angle from the integrated navigation system. The atmospheric data interface unit is used by the helicopter to obtain takeoff and landing speed data from the atmospheric data system. The obstacle data interface unit is used to obtain the azimuth, distance and height data of obstacles in front from the helicopter's airborne collision avoidance radar, and after data conversion, the obstacle information is displayed in the helicopter's integrated display and control system. The data verification unit is used to determine the validity of the received key parameters. If any key parameter is invalid, an error code is output on the display screen, and the system is controlled to enter a degraded mode that only displays a static background.

[0008] Furthermore, the comprehensive situational awareness image generated by the geographic information processing module adopts an overlay architecture of bottom, middle, and top layers: The bottom layer is a layered, color-coded 3D terrain background dynamically generated based on a digital elevation model, with colors divided according to the real-time altitude of the helicopter. The middle layer is an obstacle symbol layer superimposed on the terrain background, used to mark the location and outline of isolated objects, high-voltage lines and high-voltage towers after radar detection and database fusion processing; The top layer is an overlay display of flight parameters and warning information, including at least a track scale, navigation parameters, and a prominent warning text box.

[0009] Furthermore, the color division rules for the layered color-coded three-dimensional terrain background are as follows: The red area indicates terrain with an altitude higher than the helicopter's current altitude; The yellow area indicates terrain located below the helicopter, with a vertical height difference of less than or equal to 100 meters between the helicopter and the terrain. The green area indicates terrain located below the helicopter, with a vertical height difference between the helicopter and the terrain greater than 100 meters but less than or equal to 200 meters. The gray area indicates terrain located below the helicopter, with a vertical height difference of more than 200 meters between the helicopter and the terrain.

[0010] Furthermore, the threat assessment and alarm calculation module includes a forward alarm calculation unit: Along the flight path, establish a rectangular calculation area with a length equal to the predicted flight time multiplied by the current ground speed and a width covering the horizontal positioning error; Elevation data of terrain profiles in the area are extracted at a preset sampling interval and fused with obstacle database and real-time detected obstacle information to form a model, and the effective height of the obstacle is assigned to the grid area in which it is located. The generated integrated terrain profile is compared with the warning threshold line located below the predicted track line to determine whether the terrain or obstacle penetrates the warning threshold line from bottom to top, and the warning and attention levels are divided according to the time interval to which the penetration occurs.

[0011] Furthermore, the threat assessment and alarm calculation module includes a vertical alarm calculation unit: Centered on the helicopter's current position projection point, a square monitoring area covering the horizontal positioning error range is defined, and the maximum terrain elevation within this area is extracted as the terrain elevation directly below. Calculate the real-time vertical altitude difference between the helicopter's current altitude and the altitude of the terrain directly below it; Calculate the altitude alarm threshold based on the helicopter's current climb and fall rate and vertical safety margin; The real-time vertical height difference is compared with the height alarm threshold. When the height alarm threshold is greater than or equal to the vertical height difference, a warning-level alarm is triggered directly.

[0012] Furthermore, the threat assessment and alarm calculation module includes an alarm priority arbitration mechanism: warning-level alarms have higher priority than attention-level alarms; under the same alarm level, terrain-triggered alarms have higher priority than obstacle-triggered alarms; the system only outputs the alarm content with the highest priority at any given time and suppresses the visual and auditory output of low-priority alarms.

[0013] Furthermore, the multimodal alarm output and interaction module includes an alarm suppression management unit: responding to alarm suppression commands from the helicopter integrated display control system, the system enters an alarm suppression state; in the alarm suppression state, all visual flashing effects of alarm information, display of warning text boxes, and output of voice alarm signals are blocked, and alarm suppression text prompts are only retained in the status bar of the display screen; the threat assessment and alarm calculation module in the system background continues to run to maintain continuous awareness of the environmental situation.

[0014] Furthermore, the voice alarm function of the multimodal alarm output and interaction module includes: sending a trigger signal containing the alarm level and type to the helicopter integrated display control system; the integrated display control system controls the intercom system to broadcast the corresponding pre-recorded voice prompts according to the received signal; the tone, speed and content of the voice prompts correspond to the level of the visual alarm, with the warning level using urgent commanding voice and the attention level using gentle prompting voice.

[0015] One or more technical solutions provided in this application have at least the following technical effects or advantages: By integrating multi-source data, precise perception and dynamic modeling of the helicopter flight environment are achieved. A threat assessment mechanism, combined with a safety margin model, provides early warnings of terrain and obstacle collision risks, effectively solving the blind spot problem of traditional systems. An intuitive 3D situation map is generated based on the helicopter's real-time altitude, enhancing the pilot's situational awareness. Intelligent alarm arbitration, multimodal output, and controllable alarm suppression functions work together to ensure clear critical alarms and grant pilots flexible control, improving flight safety and human-machine interaction efficiency in complex low-altitude environments. Attached Figure Description

[0016] Figure 1 This is an architecture diagram of a helicopter terrain prompting and alarm system based on a digital map, as described in an embodiment of the present invention. Figure 2 This is a topographic profile data acquisition area map in an embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of the trajectory direction alarm in an embodiment of the present invention. Detailed Implementation

[0017] To facilitate understanding of the present invention, a more complete description of this application will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to enable a more thorough and complete understanding of the disclosure of the present invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0019] Example 1: As Figure 1 As shown, a helicopter terrain prompting and warning system based on digital maps is presented.

[0020] The data acquisition and verification module is used to acquire the helicopter's navigation parameters, atmospheric data, and obstacle information detected by sensors in real time through the airborne data bus, and to perform validity verification and fusion processing on each data source. The data acquisition and verification module includes: The navigation data interface unit is used by the helicopter to obtain its position, altitude, ground speed, heading, and track angle from the integrated navigation system. The atmospheric data interface unit is used by the helicopter to obtain takeoff and landing speed data from the atmospheric data system. The obstacle data interface unit is used to obtain the azimuth, distance and height data of obstacles in front from the helicopter's airborne collision avoidance radar, and after data conversion, the obstacle information is displayed in the helicopter's integrated display and control system. The data verification unit is used to determine the validity of the received key parameters. If any key parameter is invalid, an error code is output on the display screen, and the system is controlled to enter a degraded mode that only displays a static background.

[0021] Specifically, the system interconnects with the helicopter's integrated navigation system via the ARINC429 data bus to obtain data such as the helicopter's position (longitude, latitude), altitude, ground speed, heading, track angle, and time stamp; it interconnects with the helicopter's atmospheric data system via the 1553B / RS422 data bus to obtain the climb and fall rates; it acquires data such as the azimuth, distance, and altitude of obstacles (such as isolated objects, high-voltage lines / towers) detected by the helicopter's onboard collision avoidance radar via the UDP bus; it receives alarm suppression control commands from the integrated display control system via the RS422 data bus; it reports alarm information to the integrated display control system via the RS422 data bus; and it outputs display video signals to the integrated display control system via the differential XGA digital video signal interface.

[0022] The validity of each data source is verified. If any key parameter is invalid (such as location failure or abnormal altitude data), "Failed XX" will be displayed in the upper right corner of the screen, where "XX" is a preset failure code (such as 01 for GPS failure and 02 for elevation speed failure). The system will enter degraded mode, display only a static terrain background, and suspend alarm calculation. If all data is valid, the normal processing flow will be resumed.

[0023] During data processing, the system monitors the command signals of the integrated display and control system in real time. When the pilot is performing training exercises on known terrain, in an absolutely safe airspace, or in a system test scenario, and deems terrain warnings unnecessary, he can press the terrain warning suppression button on the integrated display panel. This operation generates a warning suppression control command, which is sent to the terrain prompt and warning system in real time via the RS422 data bus, and the system enters the warning suppression state.

[0024] The geographic information processing module, connected to the data acquisition and verification module, is used to read digital elevation model data and obstacle database from the airborne storage device, and dynamically generate a comprehensive situational image that includes a layered colored terrain background and superimposed obstacle symbols based on the helicopter's real-time position and altitude. The color division rules for the layered color scheme of the three-dimensional terrain background are as follows: Specifically, the digital map data relied upon by this system is stored on the onboard mSATA electronic disk and mainly consists of two parts: digital elevation model data and an obstacle database. The system reads the digital elevation model (DEM) data within a 30-kilometer radius of the flight path from the onboard mSATA electronic disk and generates a layered, color-coded 3D geographic information background in real time, based on the helicopter's current altitude: red areas represent terrain with an altitude higher than the helicopter's current position; yellow areas represent terrain below the helicopter with a vertical height difference ≤ 100 meters; green areas represent terrain below the helicopter with a vertical height difference between 100 and 200 meters; and gray areas represent terrain below the helicopter with a vertical height difference > 200 meters. This layered color scheme uses the helicopter's real-time altitude as a dynamic benchmark, providing the pilot with an intuitive, digitally-free situational awareness tool: red areas constitute the absolute threat zone, yellow is the near-ground warning zone, green is the safety buffer zone, and gray is the irrelevant zone, enabling the pilot to quickly assess the relative situation of the helicopter and the surrounding terrain.

[0025] The comprehensive situational awareness image generated by the geographic information processing module adopts an overlay architecture of bottom, middle and top layers: Specifically, the system's display adopts a fusion architecture of bottom, middle, and top layers: the bottom layer uses a layered, color-coded 3D geographic information image as the background; the middle layer overlays symbols of isolated objects and obstacles such as high-voltage lines, processed by radar and database integration; and the top layer overlays track scales, navigation parameters, and terrain / obstacle prompts and warnings. These three layers of information are fused and processed by the system to form a unified video image, which is then output to the integrated display and control system. If the current state is alarm suppression, the words "Alarm Suppression" are displayed in the status bar at the top of the 3D terrain background, informing the pilot that the alarm function has been manually disabled.

[0026] The threat assessment and alarm calculation module includes a forward alarm calculation unit: Specifically, the system establishes a rectangular computational region along the flight path. For example... Figure 2 As shown, the calculation area for the terrain profile data along the flight path is defined as a rectangular area with a horizontal gap of half a width on the left and right sides, representing the distance predicted for the flight path one minute ahead. Within the rectangular area, the elevation data of the terrain corresponding to each point is obtained from the digital map at 25-meter intervals, and the maximum value in the same horizontal row is taken as the elevation data for that row.

[0027] The polar coordinate information of obstacle location, distance, and height detected by helicopter collision avoidance radar is transformed to obtain its geographical location coordinates, height, and type attributes. This data is then fused with records in the obstacle database and modeled within the same computational area. For isolated objects, if the object is located between grid lines, its own grid and the adjacent grids before and after it are designated as valid height rows, with the height taken as the actual height of the isolated object. If the isolated object is located exactly on a grid line, only the first and last two rows are designated as valid height rows. For high-voltage power lines, only the segment of the power line within the computational area is calculated. The grid covered by this segment and the adjacent grids before and after it are designated as valid height rows, with the height taken as the maximum height value within that segment.

[0028] The threat assessment and alarm calculation module is connected to the data acquisition and verification module and the geographic information processing module, respectively. It is used to establish a forward prediction area based on the flight path and a vertical monitoring area based on the terrain directly below the helicopter. By integrating real-time terrain profiles, obstacle information and flight status, it performs threat judgment and alarm level classification based on the safety margin model. Specifically, the system determines the alarm level based on profile data and preset rules, ensuring that the unit receives the most critical alarm information through a priority mechanism. Alarm determination is based on the spatial relationship between the generated terrain profile lines and preset alarm threshold lines, such as... Figure 3 As shown, the predicted flight path (A1C1) is a straight line representing the predicted flight path of the helicopter over the next 60 seconds while maintaining its current flight path, ground speed, and climb / drop speed. The warning threshold line (A2C2) is a dashed line located below and parallel to the predicted flight path (A1C1). Its vertical distance from A1C1 is the vertical clearance, which is the safety altitude margin set by the system.

[0029] The threat assessment and alarm calculation module includes an alarm priority arbitration mechanism: Specifically, the system determines in real time whether the terrain profile line penetrates the alarm threshold line (A2C2) from below. The location of the penetration determines the alarm level: the first 30 seconds (A2B2) is a warning, and the next 30 seconds (B2C2) is a warning. The alarm level is determined by the forward prediction interval to which the penetration location belongs. Based on the type of the penetrated object (terrain or obstacle) and its penetration interval, combined with priority rules, the system determines the final alarm output. The priority rule is: warning level takes precedence over warning level; among alarms of the same level, terrain alarms take precedence over obstacle alarms; the system only outputs the alarm information with the highest current priority.

[0030] The multimodal alarm output and interaction module, connected to the threat assessment and alarm calculation module, is used to output alarm information to the cockpit display and audio system in the form of synchronized visual highlighting, text prompts and graded voice, and to receive alarm suppression commands from the pilot to control the start and stop of alarm output.

[0031] Specifically, the system ensures timely response to alarms by linking visual and auditory elements in a multi-dimensional manner. Track scales and obstacle icons are overlaid on a 3D terrain background; alarm information is displayed at the top of the screen as flashing red / yellow text boxes, such as "Ahead Terrain Warning" or "Beware of High-Voltage Lines"; if the system is in alarm suppression mode, the words "Alarm Suppression" are displayed, and alarm output is paused. While in alarm suppression mode, the system background continues to perform terrain profile calculations and threat assessments, but all flashing visual alarm symbols, warning text boxes, and audio alarm signals are disabled, with only the alarm suppression text prompt remaining in the screen status bar. This ensures pilots have continuous environmental awareness while avoiding unnecessary alarm interference.

[0032] The helicopter's integrated display and control system controls the in-flight communication system, broadcasting pre-recorded voice prompts; voice alarms and visual alarms are triggered simultaneously, enhancing the crew's situational awareness. Alarm level, location, and time data are sent to the integrated display and control system via the helicopter bus, supporting log recording and post-event analysis.

[0033] The technical solutions described in the embodiments of this application have at least the following technical effects or advantages: This application constructs a high-precision comprehensive situational awareness of the flight environment through multi-dimensional data fusion and real-time dynamic modeling. It achieves graded and proactive early warning of terrain and obstacle collision risks through forward prediction and hierarchical threshold alarm mechanisms. A dynamic, layered, color-coded 3D display based on helicopter altitude transforms complex geographic information into an intuitive situational awareness view. Multimodal synchronous output and intelligent priority management ensure timely, clear, and orderly alarm information delivery. Furthermore, a manually triggerable alarm suppression function provides pilots with flexible situational control while maintaining continuous background awareness. This enhances the helicopter's environmental awareness, threat warning timeliness, and human-machine interaction efficiency in low-altitude and complex terrain conditions, thereby reducing flight risks and ensuring flight safety.

[0034] Example 2: Example 1 achieved forward terrain prediction and warning for helicopters and 3D situational awareness, but it still has the problem of insufficient real-time monitoring and prediction of vertical height differences. This example further supplements and explains the content of Example 1.

[0035] The threat assessment and alarm calculation module includes a vertical alarm calculation unit: Specifically, the system defines a small rectangular area (e.g., 50m x 50m) centered on the helicopter's current position projection point. This area covers the possible horizontal positioning error range of the helicopter. From the digital elevation model data, the elevation values ​​of all grid points within this area are extracted, and the maximum value is taken as the terrain elevation directly below. This method can capture potential local high points within the rectangular area directly below, avoiding underestimation of risk. The real-time height difference is calculated based on the acquired data. , in, This is the real-time altitude difference, a value that is continuously updated to reflect the instantaneous vertical distance between the helicopter and the terrain. This is the helicopter's current altitude. This represents the elevation of the terrain directly below.

[0036] The system dynamically calculates the altitude alarm threshold based on the helicopter's current climb and fall speed and a preset vertical safety margin model. This threshold increases accordingly with the rate of descent to ensure early warning when the descent rate is high. The real-time vertical height difference is compared with the height alarm threshold in real time: if the conditions are met... If this occurs, a warning-level alert will be triggered immediately.

[0037] The vertical alarm determination of this system is not based on a single fixed threshold, but rather on a comprehensive and adaptively adjustable vertical safety margin model. This model consists of two parts: the basic vertical clearance ( ), providing a fixed safety height buffer (e.g., 30 meters); and a dynamic alarm height offset ( Its value is determined based on the helicopter's current descent speed. The greater the descent speed, the greater the required dynamic alarm altitude offset, thus dynamically increasing the altitude alarm threshold. The calculation formula is as follows: .

[0038] The system's vertical alarm determination adopts direct real-time logic, continuously calculating the real-time vertical height difference between the helicopter's current altitude and the altitude of the terrain directly below. And compare it with the dynamically calculated height alarm threshold. Perform real-time comparison. When the condition is met... When this occurs, it means that the real-time height difference has intruded into the safety margin, and the system immediately triggers a warning-level alarm.

[0039] To provide earlier warnings of risk trends and further refine the vertical warning logic, a trigger mechanism for attention-level warnings has been added to the existing warning-level warnings, enabling more precise early warnings of collision risks during helicopter descent. The trigger threshold is set at a larger safety boundary. When the altitude difference enters this range, the system provides voice or visual cues, enabling the pilot to perceive the risk in advance and prepare to take action, thus achieving a smooth transition from perception to warning.

[0040] For obstacles such as high-voltage power line towers and isolated objects, a unified framework integrating terrain data is employed to ensure comprehensive threat assessment. The system compares and fuses the obstacle top height data detected in real-time by collision avoidance radar with the object information stored in the airborne obstacle database. If the data matches, a weighted average is used for smoothing, outputting a higher-confidence obstacle height value. In alarm calculations, the processed obstacle top height is treated as equivalent to terrain height. The vertical distance between the helicopter and this top height is calculated and incorporated into the same vertical safety margin model and decision logic used for terrain alarms. Given the physical characteristics of obstacles, their corresponding alarm height offset can be set independently, typically less than the terrain value, to reflect different risk tolerance levels. For newly detected obstacles not found in the database, the system records and models them as high-confidence temporary targets and incorporates them into the unified threat assessment process. When the obstacle meets the alarm conditions based on the safety margin model within the forward prediction area or vertical monitoring area, the system triggers an alarm of the corresponding level. After the flight is completed, the data packets of these newly added obstacles can be exported, verified on the ground, and used to update the obstacle database of the entire fleet.

[0041] The voice alarm function of the multimodal alarm output and interaction module includes: Specifically, after the alarm determination is completed, the system integrates alarm information with visual and auditory multi-channels in a closely coordinated manner to ensure that the pilot can receive and understand risk information in a timely and accurate manner. Against a 3D terrain background, the system overlays and renders the high-risk area directly below (i.e., the area that triggered the alarm) with strongly flashing red highlighted graphics (such as apertures or crosshairs). In a fixed area of ​​the screen, the system displays the current vertical altitude difference and the minimum expected future altitude difference calculated based on the forward prediction area of ​​the flight path side-by-side in numerical / bar graph form, providing the pilot with continuous safety trend awareness, enabling them to proactively detect the evolving risk trend before the system triggers a formal alarm. The auditory channel and visual cues are strictly synchronized and respond in a graded manner. When a warning level is triggered, the system broadcasts a rapid, commanding voice message; when an attention level is triggered, a calm, suggestive voice message is broadcast. The voice content directly corresponds to the alarm level, reinforcing the pilot's sense of urgency and suggesting evasive maneuvers. When multiple threats trigger alarm conditions simultaneously, the system only outputs and highlights the alarm content with the highest priority. Other identified but lower-priority threats will be displayed in a minimalist manner at the edge of the display area, such as small gray icons. This ensures that while the pilot is focusing all their attention on dealing with the most urgent threat, their peripheral vision can still maintain a baseline perception of the global threat distribution without interference, thereby avoiding information overload and guiding the pilot to focus on handling the most critical situations.

[0042] The technical solutions described in the embodiments of this application have at least the following technical effects or advantages: This application achieves comprehensive early warning of terrain and obstacle collision risks through multi-dimensional data fusion and real-time dynamic modeling. The forward prediction area mechanism effectively solves the forward blind spot problem of traditional near-ground warning systems, providing graded warnings for potential terrain threats such as ridges and steep slopes ahead of the flight path. The vertical monitoring area, based on real-time altitude difference and dynamic safety margin models, makes refined judgments on risks during descent and near-ground flight phases. This forms a comprehensive early warning system covering the entire flight process and taking into account both horizontal and vertical directions. Utilizing data fusion and a self-evolving obstacle handling mechanism, the system is endowed with the ability to continuously learn and adapt to the environment; and by integrating multi-modal output and global threat priority arbitration, efficient and orderly human-machine interaction and the integration of contextual awareness are ensured. This improves the flight safety of helicopters in complex low-altitude environments throughout all phases, and is particularly suitable for mission scenarios with variable terrain and obstacles, such as mountainous areas and urban areas.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A helicopter terrain warning and alert system based on digital maps, characterized in that, include: The data acquisition and verification module is used to acquire the helicopter's navigation parameters, atmospheric data, and obstacle information detected by sensors in real time through the airborne data bus, and to perform validity verification and fusion processing on each data source. The geographic information processing module, connected to the data acquisition and verification module, is used to read digital elevation model data and obstacle database from the airborne storage device, and dynamically generate a comprehensive situational image that includes a layered colored terrain background and superimposed obstacle symbols based on the helicopter's real-time position and altitude. The threat assessment and alarm calculation module is connected to the data acquisition and verification module and the geographic information processing module, respectively. It is used to establish a forward prediction area based on the flight path and a vertical monitoring area based on the terrain directly below the helicopter. By integrating real-time terrain profiles, obstacle information and flight status, it performs threat judgment and alarm level classification based on the safety margin model. The multimodal alarm output and interaction module, connected to the threat assessment and alarm calculation module, is used to output alarm information to the cockpit display and audio system in the form of synchronized visual highlighting, text prompts and graded voice, and to receive alarm suppression commands from the pilot to control the start and stop of alarm output.

2. The helicopter terrain prompting and alarm system based on digital maps as described in claim 1, characterized in that, The data acquisition and verification module includes: The navigation data interface unit is used by the helicopter to obtain its position, altitude, ground speed, heading, and track angle from the integrated navigation system. The atmospheric data interface unit is used by the helicopter to obtain takeoff and landing speed data from the atmospheric data system. The obstacle data interface unit is used to obtain the azimuth, distance and height data of obstacles in front from the helicopter's airborne collision avoidance radar, and after data conversion, the obstacle information is displayed in the helicopter's integrated display and control system. The data verification unit is used to determine the validity of the received key parameters. If any key parameter is invalid, an error code is output on the display screen, and the system is controlled to enter a degraded mode that only displays a static background.

3. The helicopter terrain prompting and alarm system based on digital maps as described in claim 1, characterized in that, The comprehensive situational awareness image generated by the geographic information processing module adopts an overlay architecture of bottom, middle and top layers: The bottom layer is a layered, color-coded 3D terrain background dynamically generated based on a digital elevation model, with colors divided according to the real-time altitude of the helicopter. The middle layer is an obstacle symbol layer superimposed on the terrain background, used to mark the location and outline of isolated objects, high-voltage lines and high-voltage towers after radar detection and database fusion processing; The top layer is an overlay display of flight parameters and warning information, including at least a track scale, navigation parameters, and a prominent warning text box.

4. The helicopter terrain prompting and alarm system based on digital maps as described in claim 3, characterized in that, The color division rules for the layered color scheme of the three-dimensional terrain background are as follows: The red area indicates terrain with an altitude higher than the helicopter's current altitude; The yellow area indicates terrain located below the helicopter, with a vertical height difference of less than or equal to 100 meters between the helicopter and the terrain. The green area indicates terrain located below the helicopter, with a vertical height difference between the helicopter and the terrain greater than 100 meters but less than or equal to 200 meters. The gray area indicates terrain located below the helicopter, with a vertical height difference of more than 200 meters between the helicopter and the terrain.

5. A helicopter terrain warning and alerting system based on a digital map as described in claim 1, characterized in that, The threat assessment and alarm calculation module includes a forward alarm calculation unit: Along the flight path, establish a rectangular calculation area with a length equal to the predicted flight time multiplied by the current ground speed and a width covering the horizontal positioning error; Elevation data of terrain profiles in the area are extracted at a preset sampling interval and fused with obstacle database and real-time detected obstacle information to form a model, and the effective height of the obstacle is assigned to the grid area in which it is located. The generated integrated terrain profile is compared with the warning threshold line located below the predicted track line to determine whether the terrain or obstacle penetrates the warning threshold line from bottom to top, and the warning and attention levels are divided according to the time interval to which the penetration occurs.

6. The helicopter terrain prompting and alarm system based on digital maps as described in claim 1, characterized in that, The threat assessment and alarm calculation module includes a vertical alarm calculation unit: Centered on the helicopter's current position projection point, a square monitoring area covering the horizontal positioning error range is defined, and the maximum terrain elevation within this area is extracted as the terrain elevation directly below. Calculate the real-time vertical altitude difference between the helicopter's current altitude and the altitude of the terrain directly below it; Calculate the altitude alarm threshold based on the helicopter's current climb and fall rate and vertical safety margin; The real-time vertical height difference is compared with the height alarm threshold. When the height alarm threshold is greater than or equal to the vertical height difference, a warning-level alarm is triggered directly.

7. A helicopter terrain warning and alerting system based on a digital map as described in claim 1, characterized in that, The threat assessment and alarm calculation module includes an alarm priority arbitration mechanism: warning-level alarms have higher priority than attention-level alarms; under the same alarm level, terrain-triggered alarms have higher priority than obstacle-triggered alarms. The system only outputs the alarm content of the highest priority at any given time, and suppresses the visual and auditory output of low-priority alarms.

8. A helicopter terrain warning and alerting system based on a digital map as described in claim 1, characterized in that, The multimodal alarm output and interaction module includes an alarm suppression management unit: responding to alarm suppression commands from the helicopter integrated display control system, the system enters an alarm suppression state; in the alarm suppression state, all visual flashing effects of alarm information, display of warning text boxes, and output of voice alarm signals are blocked, and alarm suppression text prompts are only retained in the status bar of the display screen; the threat assessment and alarm calculation module in the system background continues to run to maintain continuous awareness of the environmental situation.

9. A helicopter terrain warning and alert system based on a digital map as described in claim 1, characterized in that, The voice alarm function of the multimodal alarm output and interaction module includes: sending a trigger signal containing the alarm level and type to the helicopter integrated display control system; the integrated display control system controls the intercom system to broadcast the corresponding pre-recorded voice prompts according to the received signal; the tone, speed and content of the voice prompts correspond to the level of the visual alarm, with the warning level using a rapid commanding voice and the attention level using a gentle prompting voice.

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