A forehead tactile feedback-based blind navigation assistance system and method

Abstract

The application discloses a forehead tactile feedback-based blind navigation auxiliary system and method, and belongs to the field of barrier-free navigation and tactile man-machine interaction. The system comprises a head environment perception terminal, a mobile terminal and a forehead tactile output component. The mobile terminal processes environment perception data to generate micro navigation instructions, calls an electronic map to generate macro navigation instructions, and selects, covers, fuses or time-sequences the two types of instructions according to priority rules to generate final navigation instructions, which are converted into a tactile driving sequence. The forehead tactile output component outputs layered tactile codes according to the tactile driving sequence to realize navigation guidance; when an emergency risk is detected, the priority of the micro instructions is raised and an emergency mode tactile sequence is generated. The application realizes the cooperation of macro path guidance and near-field obstacle avoidance without occupying the auditory channel, and improves the continuity and traffic safety of navigation in a complex environment.

Description

Technical Field

[0001] This invention belongs to the field of barrier-free navigation and tactile human-computer interaction, and particularly relates to a navigation assistance system and method for the blind based on forehead tactile feedback. Background Technology

[0002] Existing navigation solutions for the visually impaired are generally divided into two categories: one focuses on macro-level route guidance, such as voice navigation based on electronic maps; the other focuses on near-field obstacle alerts, such as white canes, ultrasonic or camera-based sensing devices. The former can solve the "where to go" problem, but it is insufficient in covering immediate risks such as near-field dynamic obstacles, steps, potholes, head obstacles, and narrow passages; the latter can provide local obstacle avoidance, but it is difficult to provide complete continuous route guidance.

[0003] Meanwhile, voice broadcasts continuously occupy the user's auditory channels, affecting their safety perception of vehicle, pedestrian, and environmental sounds; hand, wrist, or handheld vibration alerts can easily interfere with actions such as holding a cane, gripping, or carrying objects. In complex urban environments, users need both map-based macro navigation and real-time alerts of environmental changes within a few meters ahead, which existing single-channel or single-level solutions cannot adequately address.

[0004] Therefore, a system solution is needed that can combine head environmental perception, mobile terminal intelligent processing, and forehead structured tactile feedback to complete the closed loop of "environmental recognition - navigation decision - information fusion - real-time tactile output" under a unified architecture. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a navigation assistance system for the blind based on forehead tactile feedback, comprising: Head-mounted environmental sensing terminal, used to collect environmental sensing data in front of the user; A mobile terminal is communicatively connected to the head-mounted environmental perception terminal. The mobile terminal is used to process the environmental perception data to generate micro-navigation instructions and to generate macro-navigation instructions based on electronic map information. The mobile terminal is also used to select, cover, fuse, or arrange the micro-navigation instructions and the macro-navigation instructions in sequence according to a preset priority rule to generate a final navigation instruction and to convert the final navigation instruction into a haptic drive sequence. A forehead tactile output component, worn on the user's forehead, includes a circumferential tactile array and a central dot matrix tactile array, used to output layered tactile codes according to the tactile driving sequence to achieve navigation guidance for the user; When the mobile terminal detects a risk event that meets preset emergency conditions based on the environmental perception data, the mobile terminal increases the priority of the micro-navigation command and generates a haptic drive sequence corresponding to the emergency mode to guide the user's navigation.

[0006] Optionally, the mobile terminal includes: The micro-obstacle avoidance and road condition recognition module is used to identify obstacles or road condition events within a preset near-field range centered on the user, and to generate the micro-navigation instructions. The macro-map navigation module is used to call up electronic maps for route planning and guidance, and to generate the macro-navigation instructions; The arbitration fusion module is used to select, cover, fuse, or arrange the micro navigation instructions and the macro navigation instructions according to the preset priority rules, and generate the final navigation instructions. A tactile encoding and driving module is used to convert the final navigation command into the tactile driving sequence.

[0007] Optionally, in the forehead tactile output component, the circumferential tactile array is used to output directional tactile codes, and the central dot matrix tactile array is used to output dot matrix tactile codes of road conditions, actions, or emergency levels.

[0008] Optionally, when there is no risk event that meets the preset emergency conditions, the mobile terminal outputs the macro navigation command and uses the road condition event corresponding to the micro navigation command as an overlay prompt or verification prompt.

[0009] Optionally, within the same prompting cycle, the directional tactile code and the dot matrix tactile code are output synchronously, or the directional tactile code is output first and then the dot matrix tactile code is output in a fixed sequence.

[0010] Optionally, in the emergency mode, the method of generating the tactile drive sequence includes: increasing the repetition frequency, increasing the intensity level, extending the pulse width, increasing the number of repetitions, and outputting a stop-specific dot matrix pattern.

[0011] Optionally, the mobile terminal is further configured to determine the repetition frequency or pulse interval of the tactile output in the tactile driving sequence based on the distance to the obstacle, and the closer the distance, the higher the repetition frequency or the shorter the pulse interval.

[0012] This invention also provides a navigation assistance method for the blind based on forehead tactile feedback, comprising: Collect environmental perception data in front of the user; The environmental perception data is processed to generate microscopic navigation commands; Generate macro navigation instructions based on electronic map information; The micro-navigation instructions and the macro-navigation instructions are selected, covered, merged, or arranged in sequence according to preset priority rules to generate the final navigation instructions; The final navigation command is converted into a haptic drive sequence and drives the haptic output component worn on the user's forehead to output layered haptic codes to guide the user's navigation. Specifically, when a risk event that meets preset emergency conditions is detected based on the environmental perception data, the priority of the micro-navigation command is increased and a tactile drive sequence corresponding to the emergency mode is generated to guide the user's navigation.

[0013] Optionally, the preset emergency conditions include: the nearest obstacle is less than a first threshold, the predicted collision time is less than a second threshold, the passable width within the travel direction sector is less than a third threshold, and a head-height obstacle is detected and its distance is less than a fourth threshold.

[0014] Optionally, before converting the final navigation command into a haptic drive sequence, a haptic calibration step is also included: adaptively setting the haptic output intensity threshold and the minimum discernible pulse width based on the user's forehead sensitivity parameters.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: This invention integrates head environment perception, mobile terminal computing, and forehead tactile feedback modules to construct a complete closed loop from environment recognition to tactile output, achieving collaborative processing of macro-map navigation and micro-near-field obstacle avoidance. Through an arbitration fusion mechanism, it prioritizes, covers, merges, or sequentially arranges micro-navigation commands and macro-navigation commands, effectively resolving the conflict problem of multi-source navigation commands and maintaining the continuity of path guidance while ensuring timely response to emergency risks. Through layered tactile encoding output of the forehead circumferential tactile array and the central dot matrix tactile array, information such as direction, road conditions, actions, and emergency levels is transmitted to the user in a structured tactile manner, freeing up the auditory channel and avoiding interference with environmental sound perception. Furthermore, through overlay and verification prompts in non-emergency modes, enhanced tactile strategies in emergency modes, and adaptive calibration of user sensitivity, it further improves traffic safety, information discernibility, and product applicability in complex scenarios. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is an overall structural diagram of the navigation assistance system according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating the information processing of the navigation assistance system according to an embodiment of the present invention. Figure 3 This is a flowchart of a navigation assistance method for the blind according to an embodiment of the present invention. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0019] Example 1 like Figure 1 As shown, this embodiment provides a navigation assistance system for the blind based on forehead tactile feedback. The user wears a head-mounted device integrating a head sensing module. The mobile terminal computing module is deployed on a mobile phone, and the forehead tactile feedback module is fixed to the user's forehead area. The head sensing module continuously collects environmental data and sends it to the mobile phone; the mobile phone simultaneously acquires positioning and map navigation information, processes the two types of information uniformly, and outputs tactile commands to the forehead tactile feedback module. Specifically, this includes: The head-mounted environmental perception terminal is used to collect environmental perception data in front of the user, including image data and depth data. A mobile terminal is communicatively connected to the head-mounted environmental perception terminal. The mobile terminal is used to process the environmental perception data to generate micro-navigation instructions and to generate macro-navigation instructions based on electronic map information. The mobile terminal is also used to select, cover, fuse, or arrange the micro-navigation instructions and the macro-navigation instructions in sequence according to a preset priority rule to generate a final navigation instruction and to convert the final navigation instruction into a haptic drive sequence. A forehead tactile output component, worn on the user's forehead, includes a circumferential tactile array and a central dot matrix tactile array, used to output layered tactile codes according to the tactile driving sequence to achieve navigation guidance for the user; When the mobile terminal detects a risk event that meets preset emergency conditions based on the environmental perception data, the mobile terminal increases the priority of the micro-navigation command and generates a haptic drive sequence corresponding to the emergency mode to guide the user's navigation.

[0020] Furthermore, mobile terminals include: The micro-obstacle avoidance and road condition recognition module is used to identify obstacles or road condition events within a preset near-field range centered on the user, and generate the micro-navigation instructions; the preset near-field range is 2m to 15m, and in this embodiment it is 10m; the micro-navigation instructions include at least one or more of the following: obstacle distance, obstacle orientation, obstacle height category, steps, stairs, ramps, and pothole road condition categories.

[0021] The macro-map navigation module is used to call the electronic map for route planning and guidance, and generate the macro-navigation instructions. The macro-navigation instructions include at least the route guidance direction, intersection type, turning action, and remaining distance to the turning point. The remaining distance is used to trigger an advance warning window.

[0022] The arbitration fusion module is used to select, cover, fuse, or arrange the micro navigation instructions and the macro navigation instructions according to the preset priority rules, and generate the final navigation instructions. Priority rules should include at least: (1) When there is a micro-risk event that meets the emergency conditions, output the micro-navigation command and override the macro-navigation command; (2) When there is no micro-risk event that meets the emergency conditions, output macro navigation instructions and use micro-road condition events as superimposed prompts or verification prompts.

[0023] A tactile encoding and driving module is used to convert the final navigation command into the tactile driving sequence.

[0024] Furthermore, in the forehead tactile output component, the circumferential tactile array is used to output directional tactile codes, and the central dot matrix tactile array is used to output dot matrix tactile codes of road conditions, actions, or emergency levels.

[0025] In this embodiment, the central dot matrix tactile array is a 3×3 or 2×2+1 array, with a 3×3 array being the preferred choice; the activation combination of tactile points within the array forms a road condition / action type dot matrix tactile code.

[0026] When there is no risk event that meets the preset emergency conditions, the mobile terminal outputs the macro navigation command and uses the road condition event corresponding to the micro navigation command as an overlay prompt or verification prompt.

[0027] The emergency condition must meet at least one of the following: (1) The distance d to the nearest obstacle is less than the first threshold, which is 0.8m to 1.5m; (2) The predicted collision time TTC is less than the second threshold, which is 0.8s to 1.5s; (3) The passable width w in the sector in the direction of travel is less than the third threshold, which is 0.45m to 0.70m; (4) A head height obstacle is detected and its distance dh is less than the fourth threshold, which is 1.2m to 2.0m.

[0028] Furthermore, within the same prompting period, the directional haptic code and the dot matrix haptic code are output synchronously, or the directional haptic code is output first, followed by the dot matrix haptic code, according to a fixed timing sequence. The prompting period is 100ms to 1500ms.

[0029] Furthermore, in the emergency mode, the method of generating the tactile drive sequence includes: increasing the repetition frequency, increasing the intensity level, extending the pulse width, increasing the number of repetitions, and outputting a stop-specific dot matrix pattern.

[0030] Furthermore, the mobile terminal is also used to determine the repetition frequency or pulse interval of the tactile output in the tactile driving sequence based on the distance to the obstacle, and the closer the distance, the higher the repetition frequency or the shorter the pulse interval.

[0031] Specifically, the obstacle distance is encoded by the repetition frequency and / or pulse interval of the tactile output, and satisfies the condition that the closer the distance, the higher the prompt frequency and / or the shorter the pulse interval; the mapping relationship is a piecewise mapping and / or a continuous function mapping.

[0032] Figure 2 This is a flowchart of the information processing of the navigation assistance system, which adopts a macro / micro fusion implementation method. When the system detects a need to turn at an intersection ahead and there are no high-risk obstacles in the near field, the map navigation unit takes the lead in outputting relevant navigation instructions for turning. When the system detects steps, potholes, head obstacles, or impassable areas in the near distance ahead, the arbitration fusion unit prioritizes the micro navigation instructions, overriding the current macro navigation prompts, and resumes map navigation output only after the risk has been eliminated.

[0033] The system determines the timing of real-time prompts based on the user's walking speed, obstacle distance, and risk level. For obstacles that can be avoided in advance, the first prompt is initiated when the user approaches a preset advance distance; if the user continues to approach the risk area, the prompt interval is shortened or the prompt repetition frequency is increased; the real-time prompt is terminated when the user deviates from the risk direction or the risk is eliminated.

[0034] The head sensing module can be implemented using cameras, depth sensing, ranging, or a combination thereof; the mobile terminal computing module can be implemented using a mobile phone, a dedicated processing terminal, or an edge computing unit; and the forehead tactile feedback module can call a structured tactile coding system for output.

[0035] like Figure 3As shown, this embodiment also provides a navigation assistance method for the blind based on forehead tactile feedback, including: Collect environmental perception data in front of the user; The environmental perception data is processed to generate microscopic navigation commands; Generate macro navigation instructions based on electronic map information; The micro-navigation instructions and the macro-navigation instructions are selected, covered, merged, or arranged in sequence according to preset priority rules to generate the final navigation instructions; The final navigation command is converted into a haptic drive sequence and drives the haptic output component worn on the user's forehead to output layered haptic codes to guide the user's navigation. Specifically, when a risk event that meets preset emergency conditions is detected based on the environmental perception data, the priority of the micro-navigation command is increased and a tactile drive sequence corresponding to the emergency mode is generated to guide the user's navigation.

[0036] Furthermore, the preset emergency conditions include: the nearest obstacle is less than a first threshold, the predicted collision time is less than a second threshold, the passable width within the sector in the direction of travel is less than a third threshold, and a head-height obstacle is detected and its distance is less than a fourth threshold.

[0037] Furthermore, before converting the final navigation command into a haptic drive sequence, a haptic calibration step is included: adaptively setting the haptic output intensity threshold and the minimum discernible pulse width based on the user's forehead sensitivity parameters.

[0038] The present invention has the following beneficial effects: 1) By integrating perception, computation, and interaction into a closed loop through the overall system architecture, it is easier to form a complete product solution; 2) By combining macro-map navigation with micro-near-field recognition, the system can provide both route continuity and respond to immediate risks; 3) Resolve conflicts in multi-source navigation commands through an arbitration fusion mechanism to reduce information confusion and misleading information; 4) Improve early warning capabilities and traffic safety in complex scenarios through short-range navigation and real-time prompting mechanisms; 5) By releasing the auditory channel through forehead tactile feedback, the interference of voice navigation on the perception of ambient sound is reduced.

[0039] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A forehead tactile feedback based navigation aid system for the blind, characterized in that, include: Head-mounted environmental sensing terminal, used to collect environmental sensing data in front of the user; A mobile terminal is communicatively connected to the head-mounted environmental perception terminal. The mobile terminal is used to process the environmental perception data to generate micro-navigation instructions and to generate macro-navigation instructions based on electronic map information. The mobile terminal is also used to select, cover, fuse, or arrange the micro-navigation instructions and the macro-navigation instructions in sequence according to a preset priority rule to generate a final navigation instruction and to convert the final navigation instruction into a haptic drive sequence. A forehead tactile output component, worn on the user's forehead, includes a circumferential tactile array and a central dot matrix tactile array, used to output layered tactile codes according to the tactile driving sequence to achieve navigation guidance for the user; When the mobile terminal detects a risk event that meets preset emergency conditions based on the environmental perception data, the mobile terminal increases the priority of the micro-navigation command and generates a haptic drive sequence corresponding to the emergency mode to guide the user's navigation.

2. The system of claim 1, wherein, The mobile terminal includes: The micro-obstacle avoidance and road condition recognition module is used to identify obstacles or road condition events within a preset near-field range centered on the user, and to generate the micro-navigation instructions. The macro-map navigation module is used to call up electronic maps for route planning and guidance, and to generate the macro-navigation instructions; The arbitration fusion module is used to select, cover, fuse, or arrange the micro navigation instructions and the macro navigation instructions according to the preset priority rules, and generate the final navigation instructions. A tactile encoding and driving module is used to convert the final navigation command into the tactile driving sequence.

3. The system of claim 1, wherein, In the forehead tactile output component, the circumferential tactile array is used to output directional tactile codes, and the central dot matrix tactile array is used to output dot matrix tactile codes of road conditions, actions, or emergency levels.

4. The system of claim 1, wherein, When there is no risk event that meets the preset emergency conditions, the mobile terminal outputs the macro navigation command and uses the road condition event corresponding to the micro navigation command as an overlay prompt or verification prompt.

5. The system of claim 1, wherein, Within the same prompting cycle, the directional tactile code and the dot matrix tactile code are output synchronously, or the directional tactile code is output first and then the dot matrix tactile code according to a fixed timing sequence.

6. The system of claim 1, wherein, In the emergency mode, the tactile drive sequence is generated by: increasing the repetition frequency, increasing the intensity level, extending the pulse width, increasing the number of repetitions, and outputting a stop-specific dot matrix pattern.

7. The system according to claim 1, characterized in that, The mobile terminal is also used to determine the repetition frequency or pulse interval of the tactile output in the tactile driving sequence based on the distance to the obstacle, and the closer the distance, the higher the repetition frequency or the shorter the pulse interval.

8. A navigation assistance method for the blind based on forehead tactile feedback, characterized in that, include: Collect environmental perception data in front of the user; The environmental perception data is processed to generate microscopic navigation commands; Generate macro navigation instructions based on electronic map information; The micro-navigation instructions and the macro-navigation instructions are selected, covered, merged, or arranged in sequence according to preset priority rules to generate the final navigation instructions; The final navigation command is converted into a haptic drive sequence and drives the haptic output component worn on the user's forehead to output layered haptic codes to guide the user's navigation. Specifically, when a risk event that meets preset emergency conditions is detected based on the environmental perception data, the priority of the micro-navigation command is increased and a tactile drive sequence corresponding to the emergency mode is generated to guide the user's navigation.

9. The method according to claim 8, characterized in that, The preset emergency conditions include: the nearest obstacle is less than a first threshold, the predicted collision time is less than a second threshold, the passable width within the sector in the direction of travel is less than a third threshold, and a head-height obstacle is detected and its distance is less than a fourth threshold.

10. The method according to claim 8, characterized in that, Before converting the final navigation command into a haptic drive sequence, a haptic calibration step is also included: adaptively setting the haptic output intensity threshold and the minimum discernible pulse width based on the user's forehead sensitivity parameters.

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