Laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source perception

Abstract

The invention discloses a laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source perception. The flight execution unit can precisely hover above a road, and the height and the position are adjusted according to a task instruction; the sensing acquisition unit acquires traffic flow, signal lamp state and environment brightness information in real time; the instruction scheduling unit automatically identifies a signal fault area according to the sensing data, plans a flight path and a hovering position of the unmanned aerial vehicle, and sets a display time sequence and duration of a laser signal; the laser display unit projects red, yellow and green light beams in the air to replace a ground traffic light for traffic indication; the local emergency control unit can independently execute a pre-stored rule when communication is interrupted, and continuous output of traffic signals is kept; the system can realize multi-unmanned aerial vehicle cooperative scheduling through a wireless network, has the characteristics of quick response, flexible deployment and high reliability, and remarkably improves the safety and command capability of urban traffic in an emergency state.

Description

Technical Field

[0001] This invention relates to the field of traffic control technology, and in particular to a laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source sensing. Background Technology

[0002] In existing technologies, urban road traffic signal systems generally rely on fixed ground traffic lights for traffic indication. These traffic lights are typically centrally controlled via wired power and communication lines, working in conjunction with traffic flow detectors and signal controllers to adjust the red and green light cycles to ensure orderly traffic flow. In recent years, some intelligent transportation systems have introduced networked control and remote monitoring functions, allowing traffic light status to be adjusted in real time through a monitoring center. However, their foundation remains centered on fixed equipment, lacking flexibility in equipment location and signal output methods.

[0003] However, in practical use, fixed traffic lights often experience signal interruptions, slow responses, and chaotic traffic order when encountering natural disasters, sudden power outages, road construction, or communication disruptions. Because existing systems require manual intervention or waiting for maintenance, they cannot restore normal indication functions quickly, easily causing severe traffic congestion and safety hazards. Meanwhile, traditional emergency solutions such as temporary traffic lights or police direction are inefficient in complex road conditions and are limited by environmental and human resources, making it difficult to meet the real-time dispatching needs of high-density traffic in smart cities.

[0004] Therefore, it is necessary to propose a new type of traffic emergency device that can respond quickly when traffic signal systems malfunction, has dynamic deployment capabilities, and can achieve aerial signal substitution, so as to improve the stability and reliability of urban traffic systems in emergency situations. Summary of the Invention

[0005] This application provides a laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source perception to improve the stability and reliability of urban traffic systems in emergency situations.

[0006] This application provides a laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source sensing, including: The flight execution unit is used to hover and position itself above the road and carry a traffic signal display device. The flight execution unit achieves stable hovering through an attitude control device and adjusts the hovering height and position according to the received mission instructions. The sensing and acquisition unit is located in the flight execution unit and is used to collect information on vehicle flow, traffic light operation status and ambient brightness at traffic intersections in real time, and send the collected data to the command and dispatch unit. The command scheduling unit is used to determine the traffic signal fault area based on the data from the sensing and acquisition unit, generate the drone flight path and hovering position command, and set the time sequence and duration of the laser signal display according to the traffic flow density. A laser display unit, installed below the flight execution unit, is used to emit red, yellow, and green beams according to the signal control commands issued by the command scheduling unit, in order to replace ground traffic lights for vehicle passage indication. The local emergency control unit, located in the flight execution unit, is used to independently control the laser display unit to maintain traffic signal indication according to pre-stored emergency control rules when communication with the command and dispatch unit is interrupted, thereby ensuring the continuity of traffic flow.

[0007] The command scheduling unit is connected in real time with multiple flight execution units through a wireless communication network. After detecting an abnormality in the traffic light, it automatically selects the flight execution unit closest to the target area to perform the hovering display task, thereby realizing the rapid replacement and dynamic restoration of the traffic signal.

[0008] The beneficial effects of this application mainly include: (1) When the ground traffic lights malfunction or lose power, the system can immediately identify the abnormality through the sensing and acquisition unit, and the command and dispatch unit can automatically select the nearest flight execution unit to go to the target area to perform the hovering task, thereby completing the replacement display of emergency traffic signals within a few seconds, greatly shortening the response time and ensuring the continuity and safety of traffic order. (2) The flight execution unit can automatically adjust the hovering height and position according to the road environment, traffic flow density and visibility conditions. The laser display unit can flexibly change the beam angle and brightness according to different road structures to achieve signal visibility coverage of multiple lanes and different directions, which is suitable for various scenarios such as urban main roads, temporary construction areas or complex intersections. (3) By setting up a local emergency control unit, even if the system and the dispatch center temporarily lose communication, the flight execution unit can still maintain the traffic signal display autonomously according to the pre-stored emergency control rules, avoiding signal interruption due to network abnormalities, and significantly improving the fault tolerance and operational reliability of the system. (4) This system can achieve real-time connection and task collaboration with the urban traffic management platform, form an aerial mobile signal network in the emergency command system, realize intelligent and distributed management of traffic signal equipment, and significantly enhance the city's traffic management capacity and emergency response efficiency in the event of an emergency. Attached Figure Description

[0009] Figure 1 This application provides a laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source perception, as described in the first embodiment. Detailed Implementation

[0010] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0011] The first embodiment of this application provides a laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source sensing. Please refer to... Figure 1 This figure is a schematic diagram of the first embodiment of this application. The following is in conjunction with... Figure 1 The first embodiment of this application provides a detailed description of a laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source perception.

[0012] The laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source perception includes a flight execution unit 101, a perception and acquisition unit 102, a command scheduling unit 103, a laser display unit 104, and a local emergency control unit 105.

[0013] The flight execution unit 101 is used for hovering and positioning above the road and carrying a traffic signal display device. The flight execution unit achieves stable hovering through an attitude control device and adjusts the hovering height and position according to the received mission instructions.

[0014] The flight execution unit 101 is the core component of the system of this invention. Its main function is to carry the traffic signal display device and hover stably above the road, thereby realizing the function of traffic lights as indicators. This unit typically uses a UAV platform with a multi-rotor structure as its carrier, preferably a quadcopter or hexacopter layout, to ensure good attitude stability and power redundancy even under complex airflow conditions. The fuselage structure of the flight execution unit 101 is made of lightweight, high-strength composite material, and the outer surface has a rainproof, dustproof, and anti-glare coating, enabling stable operation under various climatic conditions. The traffic signal display device and laser display module are installed at the bottom of the fuselage, and a positioning antenna and a communication antenna are installed at the top to ensure the stability and accuracy of signal transmission.

[0015] In terms of flight control, the flight execution unit 101 incorporates an attitude control device, which consists of an inertial measurement unit, gyroscope, accelerometer, magnetometer, and barometric altimeter. By collecting real-time data on the UAV's angular velocity, acceleration, attitude angle, and altitude, it achieves continuous monitoring and feedback control of the flight status. The core control logic of this device employs a closed-loop PID control structure, adjusting the speed of each motor in real-time based on the error between the target attitude and the current attitude to ensure the aircraft maintains a horizontal attitude and balance during hovering. To enhance wind resistance, the flight execution unit 101 establishes a wind speed estimation and compensation model at the software level. When the detected external wind speed exceeds a set threshold, the system automatically adjusts the output power of the motor in the corresponding direction to compensate for the deviation caused by airflow interference. Furthermore, to prevent attitude deviations due to uneven load, the flight execution unit employs an automatic center of gravity calibration mechanism when installing the traffic signal display device. This mechanism uses a micro servo motor to drive a counterweight slider, ensuring the entire system's center of gravity remains aligned with the flight axis.

[0016] The hovering positioning of flight execution unit 101 relies on a multi-source navigation system. This system integrates a Global Positioning System (GNSS), an optical flow positioning module, and a visual positioning module to achieve centimeter-level precision hovering. When the GNSS signal is blocked or interfered with by tall buildings, the system automatically switches to an optical flow and visual fusion mode, calculating the relative displacement by identifying and matching ground texture feature points to maintain a stable position. To ensure accurate positioning at night or in low-light conditions, the visual positioning module is equipped with an infrared auxiliary light source and a low-light camera to enhance the clarity of image feature extraction. Hovering altitude adjustment is jointly completed by an ultrasonic rangefinder and a barometer. After receiving mission instructions from the dispatch center, the system automatically calculates the altitude deviation of the target position and sends an adjustment signal to ensure the UAV smoothly ascends and descends to the target altitude range.

[0017] During mission execution, the flight execution unit 101 and the command and dispatch unit communicate bidirectionally via a wireless communication module. The wireless module can employ LTE, 5G, or a dedicated short-range communication protocol (such as Wi-Fi 6 Mesh) to achieve low-latency communication. The flight execution unit periodically uploads its own status parameters, including position coordinates, attitude angles, remaining battery power, and laser operating status, for real-time monitoring by the command and dispatch unit. Simultaneously, the flight execution unit can receive hovering position correction commands and laser display timing commands from the dispatch unit. To prevent communication interruptions from causing flight risks, the system has a built-in signal integrity detection mechanism. If no dispatch commands are received for several consecutive seconds, the flight execution unit automatically enters a safe hovering mode, maintaining its current position and waiting for communication to resume.

[0018] To ensure the energy stability of the flight execution unit 101, its power system is powered by a high-energy-density lithium battery pack. The battery is equipped with a temperature monitoring and power management chip, which can estimate the remaining flight time in real time based on flight power consumption and automatically trigger the return-to-home or landing logic when the battery level falls below a safe threshold. To prevent energy decay caused by high temperatures, a micro-air-cooling circulation system is installed inside the battery compartment. The temperature control module automatically adjusts the fan speed based on temperature sensor data to keep the battery within the optimal operating temperature range.

[0019] When performing traffic signal substitution tasks, the flight execution unit 101 must simultaneously maintain stable hovering and precise attitude control to ensure that the direction and coverage of the laser signal display meet traffic requirements. The attitude control logic embedded in the system can automatically adjust the fuselage yaw angle based on the road's azimuth information, ensuring that the projection direction of the laser display module is consistent with the road centerline. To prevent beam swaying or drift from affecting the pilot's visibility, the flight execution unit employs a real-time vibration suppression algorithm during hovering, rapidly compensating for minor aircraft swaying through high-frequency sampled angular velocity data to ensure stable beam indication.

[0020] Furthermore, the flight execution unit 101 possesses environmental adaptability. When rain, fog, or strong light interference is detected, the system can automatically lower its hovering altitude or adjust its hovering position to achieve optimal display results. The system incorporates an ambient brightness sensor and a laser light intensity adjustment module, which can dynamically adjust the laser output power according to changes in ambient light, avoiding excessive glare at night or insufficient brightness during the day.

[0021] In summary, the flight execution unit 101 not only achieves stable hovering and flexible attitude control, but also ensures reliable operation of the system in complex environments through multi-source positioning, communication protection, and energy management mechanisms.

[0022] Furthermore, the flight execution unit is specifically used for: Upon receiving the hovering command from the command scheduling unit, the system sequentially executes four control steps: attitude error measurement, automatic center of gravity adjustment, airflow interference compensation, and hovering position correction. This ensures stable hovering and maintains the accuracy of the laser display direction even in complex wind conditions and urban obstacle environments. In the attitude error measurement step, the flight execution unit collects the pitch angle, roll angle and yaw angle of the aircraft in real time through the built-in attitude sensor, and compares them with the reference attitude data of the previous hovering cycle to obtain the attitude error signal. The attitude error signal reflects the angular deviation of the aircraft relative to the target hovering attitude. In the automatic center of gravity adjustment step, the flight execution unit drives the miniature balance adjustment device installed inside the fuselage according to the direction and amplitude of the attitude error signal, so that the counterweight component makes a small displacement along the center of gravity axis until the pitch angle and roll angle errors detected by the attitude sensor are both lower than the set threshold; after the adjustment is completed, balance state parameters are generated. In the airflow interference compensation step, the flight execution unit judges the change in the intensity of the surrounding airflow through the barometric altitude sensor and the wind speed detection device. When the wind speed exceeds the set threshold, it calculates the required reverse thrust adjustment based on the balance state parameters and generates a reverse stabilizing force by controlling the speed difference of each rotor motor, so that the hovering attitude of the aircraft is restored to the balance state. In the hovering position correction step, the flight execution unit uses the downward positioning sensor to detect the horizontal offset of the aircraft relative to the ground target point, and combines the horizontal offset with the attitude error signal to calculate the position correction command. The horizontal deviation is gradually eliminated by adjusting the motor speed distribution until the aircraft is kept within the set hovering area and the laser display unit's beam is stably aligned with the target traffic intersection.

[0023] In this embodiment, when the flight execution unit performs the hovering task, its working process is a continuous and interdependent closed-loop control process.

[0024] Upon receiving a hovering command from the command and dispatch unit, the flight execution unit first enters the attitude error measurement phase. Attitude refers to the directional state of an aircraft in space, typically described by pitch, roll, and yaw angles. Pitch angle represents the angle at which the aircraft's nose pitches up or down relative to the horizontal plane; roll angle represents the angle at which the aircraft's wings tilt relative to the horizontal plane; and yaw angle represents the angle of rotation of the aircraft's nose within the horizontal plane. The attitude sensors built into the flight execution unit typically consist of a gyroscope, accelerometer, and magnetometer, which together output real-time attitude angle data. When the aircraft begins executing the hovering command, the system reads the reference attitude data saved in the previous hovering cycle and compares it with the real-time data collected by the current sensors.

[0025] For example, if the reference pitch angle is 0° (i.e., the aircraft is completely horizontal), and the current sensor detects a pitch angle of 2°, it indicates that the aircraft's nose is slightly pitched up by 2°. In this case, the system calculates an attitude error signal of +2°. Similarly, if the roll angle detection value is -1.5°, it indicates that the left side of the aircraft is slightly lower than the right side. The system records the direction and magnitude of these three angular deviations as a three-dimensional attitude error signal, expressed in degrees. The attitude error signal is the initial input to the entire control process, directly determining the direction and degree of compensation for the center of gravity adjustment.

[0026] Once the attitude error signal is confirmed, the system immediately enters the automatic center of gravity adjustment phase. A miniature balance adjustment device is installed inside the flight execution unit, consisting of a servo motor, a slide rail, and a counterweight assembly. The counterweight assembly is typically a high-density alloy block capable of minute linear displacement along the aircraft's center of gravity axis. The center of gravity axis is the central axis passing through the UAV's geometric center and perpendicular to the rotor plane. By changing the position of the counterweight on the center of gravity axis, the overall center of gravity distribution of the aircraft can be altered, thereby counteracting the torque imbalance caused by attitude deviations. For example, when the pitch angle deviation is +2° (nose pitches up), the system drives the servo motor to move the counterweight a certain distance towards the nose, generating a downward torque at the nose; if the roll angle deviation is -1.5° (leftward descent), the counterweight is slightly adjusted to the right, generating a reverse balancing torque. The adjustment range is automatically determined by the servo control system based on the magnitude of the attitude error signal. Assuming the aircraft's mass is 3 kg, when a pitch angle deviation of 2° is detected, the system calculates the required balancing torque to be approximately 0.1 N·m. Therefore, the counterweight needs to move about 2 mm along the slide rail to achieve balance. In this way, the aircraft's pitch and roll angles recover to a state where the error is less than a set threshold (e.g., 0.2°) within seconds. At this point, the system records the current counterweight position as a balance state parameter and uses this parameter for subsequent airflow disturbance compensation.

[0027] During the airflow interference compensation phase, the flight actuator monitors the surrounding airflow using a barometric altimeter and a wind speed detector. The barometric altimeter measures minute changes in the aircraft's altitude, while the wind speed detector (typically a miniature pitot tube or ultrasonic anemometer) detects local airflow speed and direction. When the wind speed change exceeds a system-set threshold (e.g., 2 m / s), the control system determines that the current airflow may interfere with the hovering attitude. At this point, the flight actuator calculates the necessary reverse thrust adjustment based on the equilibrium parameters. Thrust adjustment is achieved by changing the rotor motor speeds. For example, when wind blows from the left side of the aircraft, the airflow generates a torque that tilts the aircraft to the right. Upon detecting this torque, the system increases the speed of the left rotor while slightly decreasing the speed of the right rotor to generate a counter-torque to the left, restoring the aircraft to a level attitude. The degree of adjustment is determined by both the magnitude of the wind speed change and the current equilibrium parameters. For example, if the wind speed changes by 3 meters per second, the system calculates using empirical coefficients that the left rotor speed needs to be increased by approximately 80 revolutions per second to counteract the disturbance. Through this real-time adjustment, the flight actuator can maintain attitude stability under constantly changing external airflow conditions, preventing the aircraft from drifting or rotating.

[0028] After completing airflow interference compensation, the flight execution unit enters the hovering position correction phase. Hovering position refers to the precise coordinates of the aircraft on the horizontal plane, detected by a downward-looking positioning sensor. This sensor is typically an optical flow camera or a laser rangefinder module, used to detect the aircraft's horizontal offset relative to a ground reference point. When the drone experiences slight drift during wind or attitude correction, the system detects the displacement of the ground image or reflected signals, thus calculating the horizontal offset distance. For example, if the drone was originally hovering 10 meters above the center of a road intersection, and the downward-looking camera detects a 2-centimeter shift in the ground reference point image, the system calculates that the drone has shifted 2 centimeters eastward. The system combines this offset with the attitude error signal from the previous phase to generate a position correction command. If the offset direction aligns with the wind direction, the system simultaneously adjusts the motor speed and the aircraft's attitude angle to make the drone move slightly in the opposite direction until the ground reference point returns to the center position of the camera. When the offset is less than a set threshold (e.g., ±1 centimeter), the system determines that hovering position correction is complete.

[0029] The entire control process is a continuous closed loop: the attitude error measurement determines the direction of the center of gravity adjustment, the center of gravity adjustment result is used to calculate the torque for wind field compensation, and the stable state after wind field compensation serves as a prerequisite for position correction. The output data of each adjustment step is recorded and fed back in real time for the next control decision, thus forming adaptive stable hovering control. In this way, the flight actuator can not only achieve precise hovering under stable airflow conditions, but also maintain beam stability in complex environments such as sudden wind disturbances, attitude deviations, or ground reflection interference, ensuring that the projection direction of the laser display unit is always aligned with the center of the traffic intersection.

[0030] The sensing and acquisition unit 102 is located in the flight execution unit and is used to collect information on vehicle flow, traffic light operation status and ambient brightness at traffic intersections in real time, and send the collected data to the command and dispatch unit.

[0031] The sensing and acquisition unit 102 is the fundamental unit for environmental cognition and dynamic decision-making in the entire laser hovering emergency flight traffic light system. Its function is to monitor the operational status around traffic intersections in real time and generate a data stream, providing accurate input for subsequent intelligent scheduling and command generation. This unit is directly installed in the fuselage structure of the flight execution unit, generally located under the fuselage or on the side, to ensure that the sensor's field of view covers the main road direction and reduce interference caused by changes in flight attitude.

[0032] The sensing and acquisition unit 102 includes various types of sensing devices. Its core structure typically consists of a high-definition imaging module, an ambient light sensing module, a microwave or millimeter-wave vehicle detection module, a geomagnetic interference sensor, and a signal status acquisition module. The high-definition imaging module is used to acquire real-time traffic images of the intersection. Its camera can employ a wide dynamic range CMOS sensor chip to adapt to strong light, shadow, or nighttime lighting environments. The lens focal length and resolution are determined based on the road width and hovering height. For example, at a flight altitude of 20 meters, a lens field of view of approximately 90 degrees can cover an intersection area about 30 meters wide. To avoid difficulties in nighttime recognition, the imaging module is equipped with an infrared supplementary light that automatically turns on when the ambient brightness is below a set threshold, thereby ensuring image brightness and clarity.

[0033] The vehicle detection section uses microwave or millimeter-wave radar modules mounted on the bottom of the unit to detect vehicle presence and speed. These radar modules operate in the 24GHz or 77GHz frequency band and can stably identify moving targets in poor visibility conditions such as rain and fog. The system calculates the vehicle's direction and speed using the Doppler frequency shift of the radar waves and statistically analyzes the flow rate data per unit time based on the time interval between vehicles passing the detection coil. To avoid interference from multiple targets, the radar module employs a narrow-beam scanning method and uses software to perform dual filtering of reflected signals based on distance and speed thresholds, thereby ensuring the accuracy of the detection results.

[0034] Traffic light operation status detection relies on a combination of photoelectric sampling and signal modulation recognition. The built-in photosensitive probe of the sensing and acquisition unit points towards the traffic light on the ground, determining the current status of red, yellow, and green lights by measuring the intensity changes of light signals at different wavelengths. When a continuous interruption or abnormal flashing of the light signal is detected, the system automatically generates an abnormal status flag and reports it to the command and dispatch unit. To avoid interference from direct sunlight or vehicle headlight reflections, a bandwidth-selective filter is installed in front of the photosensitive probe, allowing only light of the corresponding wavelength band of the target signal to enter. Furthermore, if the urban traffic signal control system supports wireless status broadcasting, this unit can also directly read the status information of the signal controller via a short-range wireless module (such as ZigBee or LoRa) to achieve multi-channel redundancy verification.

[0035] Ambient brightness detection is another important function of the sensing and acquisition unit 102. This function is jointly performed by an ambient light sensor and a color temperature sensor. The former measures the overall light intensity, while the latter determines the surrounding color temperature characteristics. Based on the detection results, the system automatically determines whether it is daytime, nighttime, or a special lighting condition, such as a tunnel or a highly reflective area. The obtained data is not only used to help determine the reliability of the traffic light's operating status but also to provide a basis for adjusting the light intensity of the laser display unit 104, ensuring the visibility of traffic signals under different lighting conditions.

[0036] During data acquisition, the sensing and acquisition unit 102 employs an edge processing structure to reduce system latency. This unit embeds a microprocessor module to perform preliminary processing on the acquired raw images and radar data, such as vehicle counting, traffic light status markings, and illumination level determination. The processed data is packaged in timestamp format and transmitted in real-time to the command and dispatch unit 103 via a wireless communication module. Each data packet contains fields such as a unique intersection identifier, acquisition time, vehicle flow rate, red, yellow, and green light status markings, and ambient brightness level. To ensure data integrity and security, the system employs an encryption and verification mechanism, using CRC redundancy codes and AES encryption algorithms to verify and encrypt data during transmission, thereby avoiding misjudgments caused by wireless interference or spoofed signals.

[0037] In the multi-source sensing collaborative mechanism, the sensing and acquisition unit 102 not only relies on its own sensors but can also share information with the sensing units of adjacent UAVs. The UAVs exchange data via a short-range wireless networking protocol, enabling collaborative monitoring between intersections. For example, when UAVs at adjacent intersections detect traffic flow on the same road segment, they can calculate the average vehicle speed by comparing timestamps, further improving traffic flow prediction accuracy. The system design considers the synchronization issue of multi-source data fusion; therefore, each sensing and acquisition unit automatically synchronizes its clock with the scheduling unit upon startup to ensure data time consistency.

[0038] The mounting structure of the sensing and acquisition unit 102 fully considers the effects of flight vibration and airflow interference. Both the camera and radar modules employ a shock-absorbing suspension mounting method, isolated from the flight actuator body via flexible connectors to reduce detection errors caused by micro-vibrations in flight attitude. The protective covers of each sensor are made of optical-grade transparent material and have waterproof, anti-fog, and dustproof coatings to ensure reliability during long-term operation.

[0039] In terms of operation and maintenance, the sensing and acquisition unit 102 has self-testing and calibration functions. Before startup, the system automatically detects the sensor's operating status. If it detects a weak radar signal, abnormal camera frame rate, or slow response from the photosensitive probe, it will automatically report the fault information to the scheduling unit and may attempt to restart the relevant modules to recover. To maintain measurement accuracy, the system can remotely trigger a calibration program through the scheduling unit before each task to restore the camera's focal length, radar distance reference, and illumination baseline values ​​to standard states.

[0040] At the data output level, the output frequency of the sensing and acquisition unit 102 is typically set to 1 to 5 times per second, dynamically adjusted according to the sensitivity of traffic flow changes. When the system detects significant fluctuations in traffic flow, it automatically increases the sampling frequency to obtain more timely data feedback; under stable traffic conditions, the sampling frequency is reduced to save energy. All data is ultimately aggregated to the scheduling unit via a wireless network, providing high-precision real-time data for subsequent task allocation and laser signal control.

[0041] With the above structure, the sensing and acquisition unit 102 can operate stably in various complex traffic scenarios, accurately identify traffic light status and traffic flow characteristics, and promptly transmit complete data streams to the dispatching system. This unit can be constructed and operated using existing conventional hardware such as cameras, radar, photoelectric sensors, and embedded processors.

[0042] Furthermore, the sensing and acquisition unit is specifically used for: After the flight execution unit completes hovering and positioning, it sequentially performs four steps: traffic light status detection, vehicle information recognition, ambient light parameter correction, and data consistency verification, to generate comprehensive perception data for traffic condition determination and send it to the command and dispatch unit; among these, In the signal light status detection step, the sensing and acquisition unit uses a photoelectric detection device installed below the flight execution unit to detect the illumination status of the ground signal light. The photoelectric detection device includes a red light detection channel, a yellow light detection channel, and a green light detection channel. Each detection channel is equipped with a filter of a corresponding wavelength to distinguish the light intensity changes of different color light sources. When the light intensity of any channel is detected to be lower than a set threshold or to continuously flicker abnormally, a signal abnormality indicator is generated. In the vehicle information recognition step, the sensing and acquisition unit acquires real-time images of the traffic intersection through an imaging device, and determines the current traffic status of the intersection based on the number of vehicles, their driving direction, and their stopping positions in the images. When a signal anomaly sign is present and vehicles are detected to be continuously stopped in the red light direction or to be backed up beyond a set number, a traffic congestion sign is generated. In the ambient light parameter correction step, the sensing and acquisition unit uses illuminance sensor and color temperature sensor to measure the overall brightness and spectral distribution of the intersection, and adjusts the light signal detection weight in conjunction with traffic congestion signs. When the traffic flow density is higher than the preset density, the interference of headlight reflection light is corrected first. When the traffic flow density is lower than the specified density, the background light sampling ratio is increased, thereby obtaining the corrected effective light signal parameters. In the data consistency verification step, the sensing and acquisition unit cross-compares the corrected valid light signal parameters with the signal anomaly indicator and the traffic congestion indicator. When all three meet the abnormal conditions, it is confirmed that the traffic light is in a faulty state. A traffic status data packet containing the traffic light status, traffic flow information, illumination parameters and geographic coordinates is generated and sent to the command scheduling unit through the wireless communication module for task triggering.

[0043] In this embodiment, the perception and acquisition unit undertakes the core functions of traffic information perception, signal status determination, and data verification. To ensure that the UAV can accurately determine the working status of ground traffic lights and perceive the surrounding traffic environment when performing hovering traffic instruction tasks, the perception and acquisition unit starts operating after the flight execution unit completes hovering positioning. It continuously executes four related steps: traffic light status detection, vehicle information recognition, ambient light parameter correction, and data consistency verification, thereby achieving closed-loop control of adaptive perception and intelligent judgment.

[0044] During the traffic light status detection phase, the sensing and acquisition unit primarily identifies the traffic light source using a photoelectric detection device installed below the flight execution unit. This photoelectric detection device consists of three independent detection channels, used to detect the operating status of red, yellow, and green traffic lights, respectively. Each detection channel is equipped with a narrowband filter corresponding to the peak value of the traffic light's spectrum to avoid interference from other light sources (such as vehicle headlights, streetlights, or advertising screens). Specifically, the center wavelength of the filter for the red channel is 620 nm, for the yellow channel it is 585 nm, and for the green channel it is 530 nm. By installing filters in front of the photodetector, it ensures that the light signal entering the sensor is limited to the target wavelength band, thereby improving recognition accuracy. The photoelectric detection device periodically collects traffic light intensity data, for example, sampling once every 100 milliseconds. The sampled value is the relative voltage output of the light intensity (in millivolts). The system compares multiple continuously sampled data points to determine whether the traffic light's illumination status is stable. If the light intensity of any channel remains below a preset threshold (e.g., the detected value is below 30% of the reference brightness) or if an abnormal flashing frequency occurs within a set time window (e.g., the red light flashing frequency exceeds 3 Hz), the system will automatically generate a signal abnormality indicator. This indicator is saved as a preliminary judgment of the signal status and passed to the vehicle information recognition stage.

[0045] During the vehicle information recognition phase, the perception and acquisition unit acquires real-time images of the traffic intersection via an imaging device mounted on the bottom of the flight execution unit. This imaging device is typically a high-definition camera with a wide dynamic range to handle differences in illumination between strong light reflections and shadowed areas. The acquired images are segmented into multiple detection areas, corresponding to lanes in different directions at the traffic intersection. The system analyzes the number of vehicles, dwell time, and movement trajectory within each area. The number of vehicles is typically calculated using edge contour recognition, i.e., detecting vehicle boundaries based on the rectangular features of the vehicle body and the distribution of headlights. For example, if more than five vehicles remain stationary within 10 consecutive seconds in the red light direction, the system determines that there is traffic congestion. Furthermore, the system records the correspondence between vehicle movement direction and signal status. When a signal anomaly indicator is detected and vehicles continue to pass through in the direction where the light should be red, the system considers this as supplementary evidence of signal malfunction. The output of the vehicle information recognition phase is a traffic congestion indicator, which includes the number of vehicles, driving direction, dwell time, and corresponding detection area number, and is sent as input to the ambient light parameter correction phase.

[0046] During the ambient light parameter correction phase, the sensing and acquisition unit measures the overall ambient brightness and spectral distribution of the intersection using illuminance and color temperature sensors. The illuminance sensor output is typically measured in lux (Lux), while the color temperature sensor output is measured in Kelvin (K). This data is used to analyze the impact of the external environment on traffic light intensity detection. When traffic density is high, reflected light from vehicle headlights may interfere with photoelectric detection results, leading to misjudgments of traffic light status. To address this issue, the system dynamically adjusts the weighting coefficients of each detection channel based on traffic density information from traffic congestion signs. For example, when traffic density exceeds a preset threshold (e.g., more than 8 vehicles per lane), the system reduces the weight of data from low-wavelength channels (red light), as this band is easily affected by brake lights. Conversely, when traffic density is low or the road is open, the system increases the proportion of background light sampling to prevent misjudgments of light signals caused by nighttime background lighting.

[0047] After weighted correction, the system calculates the effective light signal parameters corrected for ambient light. For example, if the original detected red light signal intensity is 400 millivolts and the ambient brightness is high (20,000 Lux), then according to the set correction coefficient (e.g., 0.8), the effective light intensity is calculated to be 400 × 0.8 = 320 millivolts. This corrected value is closer to the actual illumination state of the traffic light and is used as input to the data consistency verification stage.

[0048] During the data consistency verification phase, the sensing and acquisition unit cross-validates the results of the aforementioned three steps to ensure the accuracy and stability of the judgment results. The system first checks for consistency between the signal anomaly indicator, the traffic congestion indicator, and the corrected valid light signal parameters. When all three indicate anomalies (i.e., a significant decrease in signal light intensity, obvious vehicle congestion, and the corrected light signal still below the valid threshold), the system confirms that the traffic light is in a faulty state. This confirmation process employs a multi-verification mechanism to avoid misjudgment due to a single perceived anomaly. For example, in the case of short-term flashing, even if the light intensity temporarily decreases, if vehicles still pass normally and the signal intensity recovers after light correction, it will not be judged as a fault. After verification, the system generates a traffic status data packet, which includes the signal light status result, vehicle quantity and distribution information, ambient light parameters, and the geographical coordinates of the flight execution unit. The geographical coordinates are provided by the positioning module within the flight execution unit, with an accuracy typically reaching the centimeter level. The data packet is sent to the command scheduling unit in a low-latency manner via a wireless communication module (e.g., 5G or Wi-Fi 6) to trigger subsequent flight mission scheduling and signal substitution indications.

[0049] The command scheduling unit 103 is used to determine the traffic signal fault area based on the data from the sensing and acquisition unit, generate the drone flight path and hovering position command, and set the time sequence and duration of the laser signal display according to the traffic flow density.

[0050] The command and dispatch unit 103 is the central control core of the entire laser hovering emergency flight traffic light system. Its function is to receive, analyze, and generate commands from multiple sensing and acquisition units, thereby achieving intelligent scheduling and coordinated control of multiple flight execution units. This unit is typically deployed in a server cluster of a ground traffic management center or an urban emergency traffic dispatch platform, and maintains real-time data interaction with each flight execution unit through a wireless communication network. Its design goal is to ensure that in the event of a ground traffic signal failure, target area identification, UAV task allocation, and the issuance of laser display control strategies can be completed in a very short time, thereby achieving dynamic takeover of emergency signals.

[0051] Structurally, the command scheduling unit 103 consists of a communication management module, a data processing module, a task allocation module, a path planning module, and a signal timing control module. The communication management module is responsible for establishing stable bidirectional connections with each flight execution unit, typically using a cellular network (such as 4G / 5G), a dedicated radio link, or a multi-hop mesh communication architecture. To ensure communication reliability in the complex electromagnetic environment of urban areas, this module supports a multi-channel parallel mechanism. When the main communication link experiences signal attenuation or interruption, it can automatically switch to a backup channel or the relay network of adjacent nodes, thereby maintaining the continuous transmission of mission commands. The communication management module also has real-time encryption and authentication functions; each command data packet is signed and encrypted before transmission to prevent malicious interference or signal forgery.

[0052] The main function of the data processing module is to receive multi-source data from the sensing and acquisition unit 102, including traffic flow, traffic light status, vehicle density, road brightness, weather conditions, etc., and to format, clean, and fuse this data. The module has an internal time-series alignment mechanism that uses a unified timestamp to calibrate the data sources from each source, ensuring the synchronization of the analysis. The first step in data processing is traffic light status identification: the system compares the historical signal status changes at the same intersection with the current detection data to determine whether the traffic light is abnormally stagnant or flashing. The second step is regional traffic load assessment: the system calculates a real-time congestion index based on vehicle flow, road length, and average speed. The third step is priority determination: each intersection is assigned a response weight based on its anomaly level and traffic density, enabling rapid selection of priority processing areas in subsequent task scheduling phases. The output of the data processing module is a set of structured parameters, including intersection identification, anomaly type, priority level, and real-time environmental parameters.

[0053] The task allocation module determines the target area requiring emergency takeover based on the data processing results and selects the most suitable drone from available flight execution units. Internally, the module maintains a drone status table, recording the current location, remaining battery power, payload capacity, communication quality, and task status of each flight execution unit in real time. The system calculates comprehensive indicators such as the distance between each drone and the target area, arrival time, and remaining range, selecting the drone with the highest overall score as the primary mission executor, while simultaneously selecting a backup drone on standby. When multiple abnormal intersections exist in the city, the task allocation module can perform parallel task scheduling, grouping multiple drones according to the priority and geographical location of different tasks to achieve distributed emergency response.

[0054] The path planning module is a crucial part of the command scheduling unit 103, responsible for generating and dynamically adjusting flight paths. Once the task assignment determines the target, this module calculates the optimal flight route based on the geographical information of the target area, building heights, no-fly zones, and wind direction data. Path planning employs a hierarchical control logic. First, it generates a macro-level flight path based on a geographic database, then performs local optimization by combining real-time meteorological data and flight obstacle avoidance parameters. Each path is issued to the UAV in the form of a waypoint sequence, with each waypoint containing latitude and longitude coordinates, altitude, expected speed, and hovering time. When the UAV encounters sudden turbulence, communication interference, or environmental changes during flight, the path planning module replans based on the returned data, issuing corrected paths in real-time via wireless link to ensure the UAV safely reaches its target point.

[0055] The signal timing control module is used to set the time sequence and duration of laser signal displays based on road traffic density. The system uses vehicle detection data from the sensing and acquisition unit to calculate the average waiting time and vehicle throughput rate for each direction, and generates a signal timing table based on road priority levels. The signal timing table specifies the duration and switching interval of red, yellow, and green lights for each direction, taking into account lighting conditions and laser visibility. When traffic flow changes drastically, the system can automatically adjust the timing table parameters to dynamically match the signal mode output by the laser display unit 104 with the actual traffic flow. For example, during quieter nighttime hours with less traffic, the system automatically shortens the signal cycle to reduce waiting time, while extending the green light duration during peak hours to improve traffic efficiency.

[0056] In actual operation, the command scheduling unit 103 needs to handle concurrent tasks from multiple drones and multiple intersections. Therefore, its control architecture adopts a multi-threaded asynchronous execution mechanism. Each task allocation and path update is executed by an independent thread to ensure millisecond-level response latency even when multiple anomalies occur simultaneously. To prevent task conflicts, the system has internal task mutual exclusion and priority arbitration logic. When multiple tasks involve the same drone or overlapping areas, the system automatically reorders them according to task weights to ensure that high-priority emergency points are executed first.

[0057] To improve the stability of scheduling decisions, the command scheduling unit 103 is equipped with a task confirmation and feedback mechanism. When the flight execution unit receives the path instruction, it returns a confirmation signal and continuously uploads flight status and hovering coordinates after reaching the target location. The scheduling unit compares the preset path with the actual flight trajectory; if the deviation exceeds a set range, it immediately issues a correction instruction, or, if necessary, activates a backup UAV to take over the task.

[0058] In addition, the command and dispatch unit 103 also has anomaly detection and fault-tolerant recovery functions. When a drone is detected to be unresponsive for an extended period, have an obstructed flight path, or have insufficient power, the system automatically marks it as unavailable and reassigns the task to a backup drone. This fault-tolerant mechanism ensures that the entire system can continue to operate normally even if some equipment fails, thereby significantly improving the reliability of the emergency system.

[0059] Regarding data security and log management, the instruction scheduling unit 103 encrypts and stores all scheduling instructions, path information, and task status, and automatically generates operation logs in chronological order. These logs are used for later task review and regulatory filing by traffic management departments, and also facilitate operational analysis and optimization by system maintenance personnel.

[0060] In summary, the command scheduling unit 103 achieves efficient collaboration and rapid response of multiple UAVs through multi-level functions such as communication, data processing, task allocation, path planning and signal timing control.

[0061] Furthermore, the instruction scheduling unit is specifically used for: After receiving traffic status data sent by the sensing and acquisition unit, the system sequentially performs four steps: fault area determination, task unit determination, flight path calculation, and signal display parameter setting, in order to achieve scheduling and task control of the flight execution unit. In the fault area determination step, the command and dispatch unit determines whether the traffic light is in a fault state based on the traffic light status information, traffic flow information and geographic coordinate data in the traffic status data. When the traffic light status is marked as abnormal and the light intensity attenuation value exceeds the preset threshold in multiple consecutive detection cycles, the corresponding location is determined as the traffic light fault area and fault area data is generated. In the task unit determination step, the command scheduling unit selects the target unit from multiple flight execution units that maintain wireless communication with it. Based on the location information, power information and communication delay information uploaded by each flight execution unit, it calculates a comprehensive priority score. The priority score is obtained by weighting flight distance, power adequacy and communication stability. The flight execution unit with the highest score is determined as the current execution unit. In the flight path calculation step, the command scheduling unit calculates the shortest flight path under obstacle avoidance conditions based on the fault area data and the current position data of the selected current flight execution unit. The obstacle avoidance conditions include building height and no-fly zone information. The path calculation results include flight path points, altitude commands, and estimated arrival time. In the signal display parameter setting step, the command scheduling unit sets the signal display order and duration based on the traffic density information and ambient brightness parameters provided by the sensing and acquisition unit. When the traffic density is higher than the upper limit, the green light duration is extended; when the traffic density is lower than the lower limit, the red light duration is extended; and when the ambient brightness is lower than the set value, the laser display intensity is increased. The unit generates signal display control commands and sends them to the flight execution unit for execution along with the flight path data.

[0062] In this embodiment, the command scheduling unit serves as the central control core of the system. Its main function is to receive traffic status data from the sensing and acquisition unit, comprehensively determine whether traffic lights are malfunctioning, and quickly select a suitable flight execution unit to perform the task after a fault is confirmed. Simultaneously, it calculates the flight path of the UAV from its current location to the target intersection and generates signal display control commands that match the traffic flow, thereby achieving dynamic scheduling and task control of the flight execution unit. The entire process consists of four consecutive, interconnected steps: fault area determination, task unit determination, flight path calculation, and signal display parameter setting.

[0063] During the fault area determination phase, the command and dispatch unit first analyzes the traffic status data sent by the sensing and acquisition unit. This data typically includes three parts: traffic light status information, traffic flow information, and geographic coordinate data. Traffic light status information includes the light intensity value, color channel recognition result, and signal anomaly indicator for each detection cycle; traffic flow information includes the number of vehicles, dwell time, and direction of movement; geographic coordinate data is provided by the positioning module built into the flight execution unit, used to identify the spatial location of the current intersection. The command and dispatch unit compares this data with a preset normal traffic light operation model. When the system detects that the signal anomaly indicator is in an "abnormal" state for multiple consecutive detection cycles (e.g., three consecutive sampling cycles, each cycle being 1 second), and the light intensity attenuation value is greater than a preset threshold (e.g., light intensity decrease exceeding 70%), the system determines that the traffic light is in a malfunctioning state. At this time, the command and dispatch unit marks the corresponding geographic coordinates as a "fault area" and records the current timestamp and detection source for subsequent path calculation and task assignment. The generated fault area data includes geographic coordinates, traffic light number, fault confirmation time, and traffic light status information, ensuring that subsequent task instructions can accurately correspond to the specific intersection location.

[0064] During the task unit determination phase, the command and scheduling unit selects the most suitable target unit for executing the current task from all flight execution units that maintain real-time communication. Each flight execution unit periodically uploads its own location information, battery level information, and communication latency information. Location information is used to determine flight distance, battery level information reflects the sustainability of task execution, and communication latency information is used to determine the reliability of real-time control. To quantify the priority of different units, the command and scheduling unit calculates a weighted comprehensive priority score. This score consists of three parameters: flight distance, battery adequacy, and communication stability. Flight distance is obtained by calculating the Euclidean distance between the current location of the flight execution unit and the coordinates of the target fault area; battery adequacy is expressed as the current remaining battery percentage; and communication stability is calculated based on the average latency of the last five communications. The priority score is calculated as follows: Priority Score = Distance Weight × (1 / Flight Distance) + Battery Weight × Battery Percentage + Communication Weight × (1 / Communication Latency), where the distance weight, battery weight, and communication weight are set based on practical experience, for example, 0.5, 0.3, and 0.2 respectively. Using this calculation formula, drones that are close by, have sufficient battery power, and stable communication will receive a higher score and be identified as the execution unit for the current task. The command scheduling unit then generates a task allocation table, binding the execution unit to the fault area and providing input for subsequent path calculation.

[0065] During the flight path calculation phase, the command and scheduling unit calculates the optimal flight path based on the current position of the selected flight execution unit and the target coordinates of the fault area. The "optimal flight path" refers to the path with the shortest flight distance and lowest energy consumption while satisfying obstacle avoidance constraints. To this end, the system first retrieves building height information and no-fly zone information stored in the city map database to form a spatial obstacle avoidance dataset. The path calculation employs a piecewise linear search method, dividing the spatial path from the starting point to the endpoint into multiple sub-segments, each typically 10 meters long, and detecting obstacles within each sub-segment. If an obstacle is detected that exceeds the safe flight altitude of the flight execution unit (e.g., 30 meters), the system automatically increases the flight altitude to 2 meters above the top of the obstacle to form a safe detour path. The calculated path points sequentially include coordinates (longitude, latitude, altitude), heading angle, and estimated arrival time. The estimated arrival time is calculated as: Flight Time = Distance / Average Flight Speed. For example, when the total path length is 500 meters and the average speed is 10 meters per second, the estimated flight time is 50 seconds. The system ultimately generates flight path data containing waypoint sequences and time commands, and outputs it to the signal display parameter setting stage.

[0066] During the signal display parameter setting phase, the command scheduling unit combines the traffic density information and ambient brightness parameters provided by the sensing and acquisition unit to generate corresponding signal display control commands. Traffic density information is typically expressed as the number of vehicles passing through the detection area per unit time, while ambient brightness parameters are expressed as the brightness value (in Lux) output by the illuminance sensor. The command scheduling unit adjusts the duration of the red, yellow, and green signals based on the traffic density. For example, when the detected traffic density is higher than the set upper limit (e.g., more than 60 vehicles per minute), the system automatically extends the green light duration by 20% to expedite vehicle flow; when the traffic density is lower than the lower limit (e.g., less than 15 vehicles per minute), the red light duration is extended by 10% to prevent excessively frequent signal switching. When the ambient brightness is lower than a set threshold (e.g., below 1000 Lux), the system simultaneously increases the beam power output ratio of the laser display unit, for example, from 80% to 95% of the standard power, to ensure that the nighttime signal visibility distance is no less than 100 meters.

[0067] After the signal display parameters are set, the command scheduling unit combines the flight path data and signal display control commands into a task execution command package, and sends it to the corresponding flight execution unit via the wireless communication module. Upon receiving the command package, the flight execution unit can execute the flight according to the preset path and simultaneously complete the signal display control, realizing the emergency replacement of ground traffic lights.

[0068] The laser display unit 104 is installed below the flight execution unit and is used to emit red, yellow and green beams according to the signal control commands issued by the command scheduling unit to replace the ground traffic lights for vehicle passage indication.

[0069] The laser display unit 104 is a key component in the system of this invention for replacing air traffic signal displays. Its function is to convert the signal control commands issued by the command scheduling unit 103 into visible light signals with clear color, direction, and shape characteristics, thereby providing passage instructions to ground vehicles while the UAV is hovering. This unit is installed at the bottom center of the flight execution unit 101, with its installation direction perpendicular to the horizontal plane of the aircraft, ensuring that the beam is projected vertically or obliquely onto the center of the road intersection area. To prevent beam deviation caused by airflow disturbances or aircraft vibration, the mounting structure employs a high-precision shock-absorbing mounting base and a three-axis stabilized gimbal, ensuring that the beam remains within the predetermined projection area even with minor changes in the UAV's attitude.

[0070] The laser display unit 104 consists of a light source module, optical modulation components, direction control components, power control circuit, heat dissipation mechanism, and protective structure. The light source module employs three independent laser emitters, corresponding to red, yellow, and green traffic signal colors respectively. The center wavelengths of each laser are set to 635 nm, 590 nm, and 520 nm, respectively, and their light intensity can be linearly adjusted from 0.5 watts to 5 watts to adapt to different lighting conditions and projection distances. The three lasers adopt a parallel optical path design, each equipped with a collimating lens and a beam-shaping lens group to ensure uniform output beams, small divergence angles, and consistent brightness. To prevent optical interference between different colors, the three beams are isolated and synchronized before emission via a beam splitter and combiner, ultimately forming a standard red, yellow, and green signal pattern at a common emission port.

[0071] The optical modulation component is used to flash, switch, or interrupt the continuously output laser beam according to traffic signal requirements. This component employs an electronically controlled liquid crystal shutter or a microelectromechanical mirror structure to achieve beam switching within milliseconds. The system precisely controls the lighting sequence and duration of red, yellow, and green lights by receiving signal control parameters from the dispatch unit. For example, when the dispatch unit sets the green light to last 10 seconds, the yellow light 2 seconds, and the red light 8 seconds, the control chip inside the laser display unit sequentially triggers the switching signals of the corresponding channels, causing the three-color beams to switch according to a predetermined cycle, forming a visual signal that complies with traffic regulations. To avoid visual overlap caused by switching delays, the modulation circuit uses a synchronous phase-locked loop mechanism to ensure that the switching time error of each channel is less than 10 milliseconds.

[0072] The direction control component is responsible for adjusting the laser beam's illumination angle and coverage area to ensure optimal signal visibility under different altitudes and road layouts. This component consists of two independent servo rotation axes, controlling the beam's rotation range in the pitch and yaw directions respectively. The pitch angle is typically set between 0 and 45 degrees to adjust the beam projection angle based on the UAV's hovering altitude, ensuring the beam spot covers the optimal center of the target area on the ground. The yaw angle adjustment range is up to 360 degrees, used for signal display in different directions at complex multi-directional intersections. When there are multiple lanes or traffic flows in different directions at a road intersection, the direction control component can quickly switch the beam direction under the control of the command and dispatch unit to sequentially indicate vehicles in different directions.

[0073] The power control circuit automatically adjusts the laser output intensity based on ambient brightness and weather conditions, ensuring the signal is clearly visible without glare. This circuit connects to the ambient brightness data provided by the sensing and acquisition unit 102. When the system detects strong light (such as direct midday light or snow reflection), it automatically increases the laser power; conversely, at night or in low-light conditions, the system reduces the output power to avoid glare or interference with the driver's vision. The power control circuit employs a constant current drive, ensuring high output stability with power fluctuations not exceeding ±1% of the rated value. Furthermore, it uses pulse width modulation to achieve fine-tuning of energy consumption and light intensity.

[0074] The heat dissipation mechanism is a crucial auxiliary component of the laser display unit 104, designed to prevent overheating of the light source due to prolonged high-power operation. The heat dissipation system includes an aluminum alloy heat sink base, a thermally conductive silicone layer, a miniature fan, and a temperature monitoring sensor. The temperature sensor monitors the light source module temperature in real time. When the temperature exceeds a set threshold (e.g., 70 degrees Celsius), the control circuit automatically increases the fan speed and adjusts the laser power to reduce the thermal load. The system also features a thermal failure protection mechanism; if an abnormally high and continuously rising temperature is detected, the corresponding laser channel is automatically shut down to prevent component damage.

[0075] To ensure stable operation in complex outdoor environments, the laser display unit 104 is equipped with a protective cover. The exit window uses optical glass with a light transmittance exceeding 90%, and is coated with a waterproof, anti-fog, and UV-resistant film. The outer edge of the protective cover has a nano-hydrophobic layer to prevent raindrops or dust from affecting beam transmission. The entire protective structure achieves an IP65 rating, enabling stable operation in rain, snow, dust, or high humidity environments. To further prevent vibration from affecting the optical system, flexible buffer rings are used to secure the optical components, which are then factory-calibrated and encapsulated in a sealed chamber to maintain optical axis consistency.

[0076] In terms of signal generation and control, the laser display unit 104 incorporates a microcontroller system. This system receives signal mode parameters from the command scheduling unit 103, including the illumination duration of each color, the switching interval, and the synchronization signal. Based on these parameters, the microcontroller system drives the power modulation and direction control circuits to achieve the corresponding optical signal output. During operation, the system continuously monitors the laser emission status, including current, voltage, temperature, and optical output power. When an output anomaly is detected, such as optical power attenuation or color distortion, the microcontroller system immediately reports to the local emergency control unit 105 of the flight execution unit, so that it can switch to a standby display mode or reduce the output intensity according to emergency rules.

[0077] To meet the needs of multi-intersection coordinated control, the laser display unit 104 can also support multi-channel signal display. For example, at a large intersection, a single drone can simultaneously handle signal display tasks in two directions. In this case, the system controls the beam distribution in different directions through electronic light valves, achieving synchronous output of red, yellow, and green signals in different locations. The light valve control system works in conjunction with the direction control components to ensure precise beam zoning switching without interference. For specific tasks, such as prioritizing emergency lane passage or indicating pedestrian crossings, the dispatch unit can directly change the display mode via wireless commands, causing the laser display unit to output beams of specific shapes or flashing frequencies to achieve specific traffic instructions.

[0078] The power system of the laser display unit 104 is connected to the energy management module of the flight execution unit and is powered by an independent voltage regulator module to ensure that the light source power remains stable when the UAV load fluctuates. The system adopts a dual redundant power channel design. When the main power supply experiences a voltage drop or momentary power outage, the backup power supply can automatically switch within 10 milliseconds to ensure uninterrupted signal display.

[0079] During the manufacturing and debugging phases, the laser display unit 104 undergoes rigorous optical calibration and color consistency testing. In the manufacturing process, a high-precision optical axis adjuster ensures that the red, yellow, and green lights coincide at the same projection center point, resulting in a nearly circular light spot with smooth edges. The color brightness ratio is compared to traffic signal standards, ensuring that the red light brightness is approximately 70% to 80% of the green light, and the yellow light brightness falls between the two, thus guaranteeing consistency between the driver's visual recognition and signal identification.

[0080] In summary, the laser display unit 104, through the synergistic effect of the light source module, modulation circuit, direction control component, and power management system, achieves high-brightness visible display of air traffic signals, stable timing switching, and reliable environmental adaptability.

[0081] Furthermore, the laser display unit is specifically used for: After receiving the signal display control command sent by the command scheduling unit, the system sequentially executes four steps: beam parameter analysis, optical axis direction calibration, light intensity adaptive adjustment, and spot position stabilization control, in order to achieve accurate display of red, yellow, and green laser signals and road traffic indication. In the beam parameter analysis step, the laser display unit analyzes the signal display control command, extracts the color command, light intensity parameter, duration and flash frequency parameter, and generates the beam control signal based on the analysis results; In the optical axis direction calibration step, the laser display unit calculates the laser projection offset based on the attitude angle information uploaded by the flight execution unit, and corrects the beam emission direction through the built-in pitch and yaw servo adjustment mechanism to keep the beam axis consistent with the center direction of the road. In the adaptive light intensity adjustment step, the laser display unit automatically adjusts the laser output power according to the ambient brightness parameters and traffic density parameters provided by the sensing and acquisition unit. When the ambient brightness is higher than the set value, the output power is increased; when the ambient brightness is lower than the set value, the output power is reduced; and when the traffic density is higher than the threshold, the green light display duration is extended. In the spot position stabilization control step, the laser display unit uses a ground reflection detection device to monitor the spot position in real time. When the spot is detected to deviate from the target center by more than a set threshold, it automatically sends a correction command to the optical axis calibration mechanism to restore the spot position to a stable state.

[0082] In this embodiment, the laser display unit is installed below the flight execution unit and is a key component of the entire system responsible for providing visual traffic signal substitution and directional guidance. Its working principle involves parsing and executing signal display control commands issued by the command scheduling unit, displaying red, yellow, and green lasers in a specific order, duration, and brightness to guide the passage of ground vehicles.

[0083] During the beam parameter resolution phase, the laser display unit receives signal display control commands from the command scheduling unit. These commands are sent in structured data format, including color commands, light intensity parameters, duration, and flashing frequency. The color command selects which of the red, yellow, or green laser channels to activate; the light intensity parameter sets the power level of the laser output; and the duration and flashing frequency determine the display rhythm of the laser signal. For example, when the command is "red light for 10 seconds, flashing frequency of 1 Hz, power of 80%", the system will resolve that the red channel needs to be activated for 10 seconds, flashing once per second, and maintaining an output power of 0.8 times the rated power throughout the entire display cycle.

[0084] This analysis process is implemented through an internal digital signal processing module. The module decomposes the command data into a control pulse sequence and outputs it to the corresponding laser drive circuit. The period and duty cycle of the pulse sequence are determined by the flash frequency and duration. For example, if the flash frequency is 1 Hz, the period is 1 second, and a 50% duty cycle means each flash lasts 0.5 seconds on and 0.5 seconds off. The beam control signal generated after parameter analysis is directly used to drive the laser diode, forming the reference beam required for the next step of optical axis alignment.

[0085] The optical axis alignment stage ensures that the laser projection direction is aligned with the road centerline, thus ensuring the spot accurately falls on the target area. When the flight actuator hovers in the air, slight shifts in pitch, roll, and yaw angles may occur due to airflow disturbances or attitude changes, causing the laser beam to deviate from its original target direction. To correct this deviation, the laser display unit is equipped with a pitch and yaw servo adjustment mechanism. This mechanism consists of two sets of mutually perpendicular miniature servo motors, used to adjust the up-down (pitch) and left-right (yaw) directions of the beam, respectively. The system calculates the current laser projection offset using the attitude angle information uploaded by the flight actuator.

[0086] For example, at a flight altitude of 10 meters, a 1° change in pitch angle results in a ground spot offset of approximately 10 × tan(1°) ≈ 0.175 meters. To compensate for this offset, the system automatically sends a 1° reverse correction command to the servo motor, realigning the beam with the road centerline. This adjustment process typically completes within 100 milliseconds, with a servo mechanism resolution of up to 0.05°, achieving centimeter-level spot alignment accuracy. The calibrated beam attitude parameters are then input to the adaptive light intensity adjustment stage.

[0087] During the adaptive light intensity adjustment phase, the laser display unit dynamically adjusts its laser output power based on real-time ambient brightness and traffic density parameters provided by the sensing and acquisition unit to adapt to different lighting conditions and traffic flow. Ambient brightness parameters are measured in Lux values ​​collected by a light sensor; for example, it can reach 20,000 Lux under clear daytime conditions, while at night it is only about 500 Lux. The system sets a brightness threshold range (e.g., 1000 to 8000 Lux). When the ambient brightness exceeds the upper limit, the system automatically increases the output power to 110% of the rated power to ensure sufficient contrast of the signal beam under strong light. When the ambient brightness is below the lower limit, the output power decreases to 70% of the rated power to prevent glare from affecting driver visual safety. Traffic density parameters are obtained by the sensing and acquisition unit by identifying the number of vehicles. If the detected traffic density exceeds the threshold (e.g., more than 60 vehicles per minute), the system automatically extends the green light display duration, for example, from the standard 8 seconds to 12 seconds, to expedite vehicle flow. Conversely, when the traffic density is below the threshold, the green light time is shortened and the red light interval is extended to maintain order. All adjustments to the light intensity and timing parameters are performed by the light intensity control module, which controls power by changing the laser drive current. For example, if the rated drive current of the laser diode is 1 ampere, when the system requires a 10% increase in output power, the drive current automatically increases to 1.1 amperes. The parameters after power adjustment are then transmitted as input to the spot position stabilization control stage.

[0088] The laser spot position stabilization control phase ensures that the projection position of the laser spot on the ground remains constant, unaffected by fluctuations in flight attitude or changes in wind speed. To achieve real-time correction, the laser display unit integrates a ground reflection detection device, which consists of a high-sensitivity photoelectric receiver to receive weak light signals reflected from the ground. The system determines whether the laser spot deviates from the target center by comparing the intensity distribution of the reflected signal. When the laser spot offset causes the asymmetry of the reflected signal to exceed a set threshold (e.g., when the laser spot center deviates by 5 cm, the difference in reflection intensity between the left and right sides exceeds 15%), the system calculates the offset direction and amplitude and automatically sends a correction command to the optical axis calibration mechanism.

[0089] Furthermore, the laser display unit employs a high-frequency feedback control mechanism with a sampling frequency of no less than 50 Hz, capable of performing 50 position detection and correction command outputs per second. This ensures the stability of the light spot position even under conditions of wind speed changes or aircraft vibration. For example, if a sudden gust of wind causes the light spot to momentarily shift by 10 centimeters, the system completes attitude correction within 0.1 seconds, returning the light spot to its set center position. Through this process, the laser display unit ensures that the signal light spot is always stably projected in the center of the ground traffic indication area, with the spot diameter controlled within 20 centimeters, meeting the requirement that drivers can clearly see it from a distance of 50 meters.

[0090] In summary, the laser display unit achieves coordinated control logic of signal analysis, beam direction control, dynamic adjustment of light intensity, and spot position maintenance through the above four steps, enabling stable display of red, yellow, and green laser signals under any lighting, wind speed, and attitude conditions.

[0091] The local emergency control unit 105 is located in the flight execution unit and is used to independently control the laser display unit to maintain traffic signal indication according to the pre-stored emergency control rules when communication with the command and dispatch unit is interrupted, thereby ensuring the continuity of traffic flow.

[0092] The local emergency control unit 105 is a key safety module in this invention that ensures the traffic signal display function remains operational even in the event of communication interruption or network anomalies. This unit is installed inside the fuselage of the flight execution unit 101, typically within an embedded control structure at the same level as the flight control motherboard, to achieve low-latency signal response and independent logic operation. Its design principle is to ensure that in the event of a communication interruption between the UAV and the ground dispatch system, it can automatically identify the communication interruption status and immediately take over control of the laser display unit 104, thereby maintaining the continuity and rationality of traffic signal indications and preventing traffic chaos or accidents caused by signal interruption.

[0093] The local emergency control unit 105 includes an emergency logic processing module, a rule storage module, a status detection module, a signal switching module, and a safety protection module. The emergency logic processing module has a built-in independent microcontroller chip; its computing power is comparable to the main flight control unit, but its operating logic is independent, allowing it to complete signal control tasks without relying on external network commands. Under normal communication conditions, the system is globally controlled by the command scheduling unit 103, while the emergency logic processing module operates in monitoring mode, receiving and recording task data issued by the scheduling unit in real time, including the current flight position, red-yellow-green signal switching cycle, ambient light level, and road traffic direction information. When a communication anomaly occurs, the emergency logic processing module immediately triggers a local takeover procedure after detecting continuous signal loss exceeding a preset time (typically 3 to 5 seconds), and executes a signal display maintenance strategy based on the last received task parameters.

[0094] The rule storage module stores multiple sets of preset emergency control rules. These rules are compiled and loaded into the system by traffic management departments before drone deployment, based on road type, typical traffic flow patterns, and time period characteristics. For example, the rules for one-way main road intersections differ from those for two-way symmetrical intersections; different signal cycles correspond to daytime peak hours and nighttime low-traffic periods. The rule storage module uses non-volatile storage chips, such as flash memory or EEPROM, ensuring data integrity even after a brief power outage. Internally, the module manages rule numbers for different scenarios through an index table. After taking over, the emergency logic processing module quickly retrieves and loads the corresponding rules based on road type identification and current ambient light level, ensuring the signal pattern matches the current traffic scenario.

[0095] The status detection module continuously monitors the communication status, power status, and laser display unit's operation of the flight execution unit. Communication status detection is achieved by monitoring the received signal strength indicator (RSSI) and handshake response time of the wireless module. When the signal strength remains below a set threshold or the number of response timeouts exceeds a limit, the module determines that the communication link is abnormal and issues a takeover command to the emergency logic processing module. Power status monitoring is achieved by reading battery voltage, current, and remaining capacity data in real time. If the battery level is detected to be below the emergency threshold, the system automatically enters energy-saving mode, shortens the signal cycle, and reduces laser power to extend the hovering time until the emergency mission is completed or a safe landing is achieved. Laser display status detection determines whether the output is normal by sampling the emission current and optical power feedback signal. When an optical power deviation exceeding 10% or an optical channel failure is detected, the emergency control unit immediately adjusts the output ratio or switches to a backup channel to maintain signal integrity.

[0096] The signal switching module enables a smooth transition between dispatch control and local control. Under normal conditions, the control of the laser display unit 104 is entirely driven by the signal control parameters of the command dispatch unit 103, with the local emergency control unit 105 passively monitoring. Upon confirmation of a communication anomaly, the signal switching module immediately switches the control channel to the local control circuit and simultaneously freezes the current signal state to prevent light flickering or state inconsistencies during the transition. Subsequently, the local control logic begins to execute signal switching according to the emergency cycle loaded by the rule storage module, for example, maintaining the current state for a buffer period before entering the rule-defined cyclic display mode. After communication is restored, the signal switching module, according to the system synchronization strategy, automatically relinquishes control upon detecting a timestamp update signal from the dispatch unit and synchronously restores the original signal rhythm based on the new parameters issued by the dispatch unit. This switching process employs a double-buffering mechanism, comparing local and remote control signals in parallel to ensure that the time phase error of the light output is less than 50 milliseconds, thereby avoiding visual confusion for the driver.

[0097] The safety protection module is designed to prevent erroneous outputs or safety hazards in abnormal situations. When the drone is low on power, unstable, or unable to hover stably due to strong winds, the safety protection module will immediately shut down the laser output to prevent the beam from deviating and causing safety risks. The module also has a time safety limit. If the drone continues to operate in an emergency for more than a preset maximum time limit (e.g., 30 minutes) without restoring communication, the system will gradually enter a low-power warning mode, automatically reducing the light output frequency and flashing a yellow light to alert on-site traffic police or traffic control centers to intervene.

[0098] In actual operation, the logic execution process of the local emergency control unit 105 is highly automated and fault-tolerant. When the UAV is connected to the ground system normally, the unit records operating parameters and environmental data in real time and periodically corrects its internal clock and rule index. Once communication is lost, the unit immediately activates local mode and selects the most reasonable signal rules to maintain operation based on the current traffic conditions. For example, when a decrease in traffic flow at an intersection is detected and the traffic lights are interrupted, the system automatically switches to a simplified signal mode, retaining only the alternating display of red and green lights to save energy. Under high traffic flow conditions, it maintains a complete three-color signal cycle and automatically extends the green light time to prevent traffic congestion.

[0099] In terms of software implementation, the control program of the local emergency control unit 105 adopts a modular design. The main control loop consists of a communication monitoring thread, a rule execution thread, a status feedback thread, and a safety detection thread. The threads communicate and synchronize information through shared memory, and a priority scheduling mechanism ensures that the safety detection thread has the highest response level at any given time. When a sudden system failure occurs, such as an abnormal light source or a sudden voltage drop, the safety detection thread can immediately interrupt other threads and execute protective actions.

[0100] To improve operational reliability, the local emergency control unit 105 has self-testing and log recording functions. Before each task execution, the unit automatically checks the integrity of the storage module, communication interface, and control channel; during task execution, the system records the operating status, switching events, and error codes at fixed intervals and stores them in local memory. After communication is restored, the data is automatically uploaded to the command scheduling unit 103 for subsequent analysis and maintenance.

[0101] In summary, the local emergency control unit 105, through its independent hardware structure and rule-driven logic, achieves complete autonomous control of the laser display unit in the event of a communication interruption. It can maintain the reasonable output of traffic signals according to pre-stored rules and has a complete guarantee mechanism in terms of energy, safety and communication restoration.

[0102] Furthermore, the local emergency control unit is specifically used for: After detecting a communication interruption with the command and dispatch unit, four steps are executed in sequence: communication loss confirmation, emergency rule loading, traffic signal adaptive adjustment, and signal takeover recovery, in order to independently maintain the stability and continuity of traffic signal indication under the condition of communication interruption. In the communication disconnection confirmation step, the local emergency control unit confirms the communication interruption status by detecting the continuous loss of heartbeat signals of the wireless communication link. When no confirmation signal is received from the command scheduling unit within multiple consecutive detection cycles, a communication interruption flag is generated, and the hovering position, altitude information and laser display status of the current flight execution unit are recorded as pre-interruption status parameters. In the emergency rule loading step, the local emergency control unit retrieves a pre-stored emergency control rule that matches the current traffic type from the internal memory based on the communication interruption flag. The emergency control rule is automatically connected to the corresponding signal sequence based on the laser display status recorded in the pre-interruption status parameters to prevent vehicle misjudgment caused by signal abrupt changes, and generates emergency signal execution parameters. In the traffic signal adaptive adjustment step, the local emergency control unit corrects the duration of the emergency signal in real time based on the traffic flow information provided by the sensing and acquisition unit. When the traffic flow is detected to be increased compared to the previous period, the green light duration is automatically extended. When the traffic flow decreases, the yellow light transition phase is entered in advance. The laser display power is adjusted according to the lighting conditions to ensure signal visibility. The adjustment results generate signal duration correction parameters. During the signal takeover and recovery process, the local emergency control unit continuously monitors the communication link status. When it receives the communication signal from the command and dispatch unit again, it sends the current traffic status data packet to the command and dispatch unit. After the command and dispatch unit confirms the takeover, it terminates the emergency control mode and returns to the subordinate execution state.

[0103] In this embodiment, the local emergency control unit is located inside the flight execution unit. Its function is to independently perform traffic signal display tasks when communication with the command and dispatch unit is interrupted due to signal interference, equipment malfunction, or network congestion, in order to prevent traffic intersections from falling into a disorderly state due to the interruption of control signals. This unit can not only automatically activate emergency control logic during communication interruption, but also smoothly transition back to central dispatch control after communication is restored, thereby ensuring the continuity and consistency of traffic signal display.

[0104] During the communication disconnection confirmation process, the local emergency control unit determines the communication status by detecting the "heartbeat signal" of the wireless communication link. The heartbeat signal refers to the acknowledgment data packet sent by the command and dispatch unit to the flight execution unit at fixed time intervals (e.g., every 200 milliseconds) to maintain the validity of the communication connection. The local emergency control unit records the timestamp of each received heartbeat signal using a timer. When no heartbeat signal is received for several consecutive cycles (e.g., five cycles, i.e., within 1 second), the system determines that communication has been interrupted. At this time, the control unit immediately generates a communication interruption flag and records the flight execution unit's current hovering position, altitude parameters, laser display status, attitude angle information, and the remaining time of the previous display cycle, forming the pre-interruption status parameters. These parameters are used not only to restore the logical continuity of traffic signal displays but also to prevent signal jumps during system restart.

[0105] For example, if a communication interruption occurs during the execution of a green light display task by the flight execution unit (e.g., at the 6th second of the green light), the local emergency control unit records the current signal status as "green light, lasting for 6 seconds". This information will be used to connect the emergency rules in sequence to ensure the continuity of the next step of the logic.

[0106] During the emergency rule loading process, the local emergency control unit automatically loads the emergency control rules matching the traffic intersection type from its internal non-volatile memory based on the interruption flag. Emergency control rules are independent signal control logic pre-defined for different traffic scenarios (such as intersections, T-junctions, or one-way lanes), including the duration, switching order, and phase transition method of red, yellow, and green signals. For example, for intersections, a fixed cycle of 10 seconds for green, 2 seconds for yellow, and 10 seconds for red is set. When the system detects that the green light has been running for 6 seconds before the interruption, it automatically continues the remaining 4 seconds of green light display before entering the yellow light phase, without immediately switching to red. This sequential transition mechanism prevents traffic chaos or driver misjudgment caused by sudden signal changes. After the emergency rules are loaded, the system generates emergency signal execution parameters based on the pre-interruption state, including the current signal type, remaining time, and the preset order of the next signal, for subsequent adaptive adjustment steps.

[0107] During the adaptive adjustment of traffic signals, the local emergency control unit dynamically adjusts the signal duration based on real-time traffic flow information provided by the sensing and acquisition unit. Traffic flow information includes the number of vehicles at the current intersection, queue length, and vehicle speed. Before the end of each signal cycle, the local emergency control unit performs adjustments based on the traffic flow change rate over two consecutive cycles. For example, if the average number of vehicles passing through per minute was 50 in the previous cycle and reaches 65 in this cycle, the traffic flow growth rate is (65-50) / 50=0.3, or 30%. When this growth rate exceeds a set threshold of 20%, the system automatically extends the green light duration to 1.3 times the original setting (e.g., from 10 seconds to 13 seconds) to accelerate vehicle flow; conversely, when a decrease in traffic flow exceeding 15% is detected, the green light time is shortened and the system enters the yellow light transition phase earlier to prevent wasting signal cycles with empty lights.

[0108] In addition, the local emergency control unit adjusts the laser display power based on lighting conditions. When the light intensity exceeds a preset upper limit (e.g., 10,000 Lux), the system automatically increases the laser power to 120% of the rated value to ensure long-distance visibility; when the light intensity is below the lower limit (e.g., 800 Lux), the system reduces the laser power to 70% of the rated value to prevent glare caused by excessive brightness. Through this dynamic adjustment process, a new signal duration correction parameter is generated, which is transmitted to the signal display unit in real time for execution, achieving dual adaptive control of light intensity and time.

[0109] During signal takeover recovery, the local emergency control unit continuously monitors the wireless communication link. Once it receives a communication signal from the command and dispatch unit again, it triggers the signal takeover mechanism. To prevent dual control or signal conflicts, the system includes a coordinated transition phase: after communication recovery is detected, the local emergency control unit does not immediately cease emergency control but continues to execute the current signal until its cycle ends; for example, if the current light is red, it remains red until the light ends. Simultaneously, the control unit sends a current traffic status data packet to the command and dispatch unit. This packet includes information such as the current signal type, duration, traffic density, light intensity, flight position, and timestamp. Upon receiving this data packet and issuing a takeover confirmation signal, the command and dispatch unit terminates the emergency mode, returns control to the dispatch system, and re-enters subordinate execution mode. The entire handover process typically completes within 2 seconds, ensuring smooth and synchronized signal switching.

[0110] In this embodiment, the command scheduling unit is connected in real time with multiple flight execution units through a wireless communication network. After detecting an abnormality in the traffic light, it automatically selects the flight execution unit closest to the target area to perform the hovering display task, thereby realizing the rapid replacement and dynamic recovery of the traffic signal.

[0111] In this embodiment, the dynamic collaborative control mechanism between the command scheduling unit 103 and multiple flight execution units 101 is the core logic component for realizing the emergency response function of this invention. This component involves not only the implementation of the communication network structure and data interaction mechanism, but also task allocation, target area judgment, priority selection, and dynamic recovery process.

[0112] During normal operation, all flight execution units are in standby mode, and each UAV maintains a real-time connection with the command and dispatch unit via a wireless communication module. The communication network can employ cellular mobile communication (such as 5G or LTE networks), dedicated short-range wireless communication (such as Wi-Fi 6 or ZigBee Mesh), or a multi-layered hybrid communication method. In complex urban traffic environments, to avoid signal obstruction or interruption, the system typically employs a multi-hop relay mechanism, allowing data forwarding between adjacent UAVs to ensure continuous communication coverage. After establishing a connection, each UAV periodically reports its status data to the dispatch unit, including its current location (latitude, longitude, and altitude), remaining battery power, hovering stability, motor temperature, signal strength, and current load. The dispatch unit receives this data and stores it in a real-time status database, forming a dynamic UAV status table for subsequent task allocation decisions.

[0113] When abnormal traffic signal information is detected in the monitoring data uploaded by the sensing and acquisition unit 102, the command and dispatch unit 103 immediately initiates the emergency response procedure. This abnormal information may originate from various causes, such as traffic light power failure, abnormal signal flashing, communication interruption, or loss of optical detection signals. The dispatch unit first determines the location range of the abnormal intersection by comparing it with geographic coordinate data and marks this area as the "task target area." The system has a built-in urban intersection geographic database, containing road intersection structures, traffic light locations, lane directions, height restrictions, and ground safety hovering zone coordinates. By comparing with this database, the dispatch unit can pinpoint the fault location and its corresponding optimal aerial hovering area within hundreds of milliseconds.

[0114] After determining the target area, the system calls the UAV status table to perform distance calculations and feasibility analyses on all online flight execution units. The distance calculation employs a three-dimensional Euclidean distance algorithm, while also considering obstacle distribution and weather conditions such as wind speed and rainfall along the flight path. To improve accuracy, the scheduling unit uses a map grid segmentation method to divide the urban area into several spatial grids, with each UAV assigned to a specific grid cell in real time. When a signal failure is detected within a grid area, the system automatically selects UAVs adjacent to or overlapping with that grid as candidate targets.

[0115] After candidate drones are selected, the scheduling unit compares their battery level, signal quality, current task load, and interference risk with other drones, calculating a comprehensive priority score for each drone using a weighted scoring formula. For example, drones with sufficient battery power, close proximity to the target point, and in an idle state will receive a higher score. This scoring algorithm is executed in real-time during each task scheduling, ensuring the selection of the optimal flight execution unit under different network conditions and device states. The drone with the highest score is selected as the primary mission executor, while the drone with the second highest score automatically enters standby mode as a backup mission executor. At this time, the scheduling unit packages the hovering point coordinates, flight altitude, mission cycle, and signal display timing parameters into control commands and sends them to the primary executor.

[0116] After receiving the command, the flight execution unit performs path planning confirmation. Once it confirms there are no obstacles or risks, it immediately takes off and heads to the target area. The entire process, from the detection of an anomaly to the drone's takeoff response, typically takes no more than three seconds. During flight, the drone continuously transmits its position information back to the scheduling unit. The scheduling unit calculates the estimated arrival time based on the real-time position and displays the progress status on the mission panel. If signal delays, communication fluctuations, or changes in wind speed occur en route, the scheduling unit will immediately adjust the drone's heading and hovering altitude parameters, sending corrective information via the command link.

[0117] After the drone arrives at the target location and enters a hovering state, the dispatch unit verifies whether its positioning accuracy is within the allowable range. To do this, the system requires the drone to upload integrated position data from the inertial measurement unit (IMU), GPS positioning module, and visual positioning module. If the deviation from the predetermined hovering point is less than a set value (e.g., 0.5 meters), the drone is considered to have successfully reached its destination. At this point, the dispatch unit issues a laser display activation command and simultaneously transmits the display cycle parameters for red, yellow, and green signals. The laser display unit 104 then begins outputting traffic signals according to this command, completing the replacement display of traffic lights.

[0118] During mission execution, the command scheduling unit continuously monitors the status of the primary executor and periodically receives its uploaded operational data. If the system detects that the drone's battery level has dropped to a warning level or that communication quality has deteriorated, it immediately issues a mission switchover command, transferring the mission to a backup drone. To avoid signal interruption, the backup drone will fly to a safe distance (usually within 10 meters of the primary drone's hovering point) and wait in the air. During mission switchover, it only needs to adjust its hovering position to take over the display mission, thus achieving a seamless transition.

[0119] In the event of simultaneous anomalies at multiple traffic signal points, the scheduling unit's control logic can perform parallel task allocation. The system employs a hierarchical scheduling architecture, dividing the urban area into multiple control sub-zones, each corresponding to a drone swarm. The scheduling unit automatically calculates the task load based on the traffic density and number of anomalies in each sub-zone and dynamically adjusts resource allocation among drone swarms. For example, when one area has too many tasks while adjacent areas are idle, the scheduling unit will utilize drone resources from adjacent swarms across zones to ensure a balanced global response.

[0120] Data synchronization in the communication network employs a timestamp mechanism. All UAVs maintain a synchronized clock with the scheduling unit, periodically synchronizing via Network Time Protocol (NTP) or satellite time signals. This ensures that when the system operates collaboratively with multiple UAVs, the task execution times of each UAV remain consistent, thus preventing time misalignment during signal switching or task handover.

[0121] Upon completion of the mission, the scheduling unit receives a mission completion report from the UAV, including parameters such as execution time, display duration, power consumption, signal coverage, and beam stability. This data is recorded in the scheduling log for subsequent performance evaluation and system optimization. If ground traffic signals return to normal after a malfunction, the scheduling unit verifies the signal recovery status via the sensing and acquisition unit 102 and sends a withdrawal command to the executing UAV. Upon receiving the command, the UAV shuts down the laser display unit and returns to its standby point, completing the mission loop.

[0122] The entire dynamic response and recovery process achieves system-level autonomous control and redundancy protection, ensuring both the real-time nature of task scheduling and the continuity and security of emergency signal display.

[0123] Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

Claims

1. A laser hovering emergency flight traffic light system based on intelligent scheduling and multi-source sensing, characterized in that, include: The flight execution unit is used to hover and position itself above the road and carry a traffic signal display device. The flight execution unit achieves stable hovering through an attitude control device and adjusts the hovering height and position according to the received mission instructions. The sensing and acquisition unit is located in the flight execution unit and is used to collect information on vehicle flow, traffic light operation status and ambient brightness at traffic intersections in real time, and send the collected data to the command and dispatch unit. The command scheduling unit is used to determine the traffic signal fault area based on the data from the sensing and acquisition unit, generate the drone flight path and hovering position command, and set the time sequence and duration of the laser signal display according to the traffic flow density. A laser display unit, installed below the flight execution unit, is used to emit red, yellow, and green beams according to the signal control commands issued by the command scheduling unit, in order to replace ground traffic lights for vehicle passage indication. A local emergency control unit, located in the flight execution unit, is used to independently control the laser display unit to maintain traffic signal indication according to pre-stored emergency control rules when communication with the command and dispatch unit is interrupted, thereby ensuring the continuity of traffic flow. The command scheduling unit is connected in real time with multiple flight execution units through a wireless communication network. After detecting an abnormality in the traffic light, it automatically selects the flight execution unit closest to the target area to perform the hovering display task, thereby realizing the rapid replacement and dynamic restoration of the traffic signal.

2. The smart dispatching and multi-source sensing based laser hovering emergency flight traffic light system according to claim 1, wherein, The flight execution unit is specifically used for: Upon receiving the hovering command from the command scheduling unit, the system sequentially executes four control steps: attitude error measurement, automatic center of gravity adjustment, airflow interference compensation, and hovering position correction. This ensures stable hovering and maintains the accuracy of the laser display direction even in complex wind conditions and urban obstacle environments. In the attitude error measurement step, the flight execution unit collects the pitch angle, roll angle and yaw angle of the aircraft in real time through the built-in attitude sensor, and compares them with the reference attitude data of the previous hovering cycle to obtain the attitude error signal. The attitude error signal reflects the angular deviation of the aircraft relative to the target hovering attitude. In the automatic center of gravity adjustment step, the flight execution unit drives the miniature balance adjustment device installed inside the fuselage according to the direction and amplitude of the attitude error signal, so that the counterweight component makes a small displacement along the center of gravity axis until the pitch angle and roll angle errors detected by the attitude sensor are both lower than the set threshold; after the adjustment is completed, balance state parameters are generated. In the airflow interference compensation step, the flight execution unit judges the change in the intensity of the surrounding airflow through the barometric altitude sensor and the wind speed detection device. When the wind speed exceeds the set threshold, it calculates the required reverse thrust adjustment based on the balance state parameters and generates a reverse stabilizing force by controlling the speed difference of each rotor motor, so that the hovering attitude of the aircraft is restored to the balance state. In the hovering position correction step, the flight execution unit uses the downward positioning sensor to detect the horizontal offset of the aircraft relative to the ground target point, and combines the horizontal offset with the attitude error signal to calculate the position correction command. The horizontal deviation is gradually eliminated by adjusting the motor speed distribution until the aircraft is kept within the set hovering area and the laser display unit's beam is stably aligned with the target traffic intersection.

3. The smart dispatching and multi-source sensing based laser hovering emergency flight traffic light system according to claim 1, wherein, The sensing and acquisition unit is specifically used for: After the flight execution unit completes hovering and positioning, it sequentially performs four steps: traffic light status detection, vehicle information recognition, ambient light parameter correction, and data consistency verification, to generate comprehensive perception data for traffic condition determination and send it to the command and dispatch unit; among these, In the signal light status detection step, the sensing and acquisition unit uses a photoelectric detection device installed below the flight execution unit to detect the illumination status of the ground signal light. The photoelectric detection device includes a red light detection channel, a yellow light detection channel, and a green light detection channel. Each detection channel is equipped with a filter of a corresponding wavelength to distinguish the light intensity changes of different color light sources. When the light intensity of any channel is detected to be lower than a set threshold or to continuously flicker abnormally, a signal abnormality indicator is generated. In the vehicle information recognition step, the sensing and acquisition unit acquires real-time images of the traffic intersection through an imaging device, and determines the current traffic status of the intersection based on the number of vehicles, their driving direction, and their stopping positions in the images. When a signal anomaly sign is present and vehicles are detected to be continuously stopped in the red light direction or to be backed up beyond a set number, a traffic congestion sign is generated. In the ambient light parameter correction step, the sensing and acquisition unit uses illuminance sensor and color temperature sensor to measure the overall brightness and spectral distribution of the intersection, and adjusts the light signal detection weight in conjunction with traffic congestion signs. When the traffic flow density is higher than the preset density, the interference of headlight reflection light is corrected first. When the traffic flow density is lower than the specified density, the background light sampling ratio is increased, thereby obtaining the corrected effective light signal parameters. In the data consistency verification step, the sensing and acquisition unit cross-compares the corrected valid light signal parameters with the signal anomaly indicator and the traffic congestion indicator. When all three meet the abnormal conditions, it is confirmed that the traffic light is in a faulty state. A traffic status data packet containing the traffic light status, traffic flow information, illumination parameters and geographic coordinates is generated and sent to the command scheduling unit through the wireless communication module for task triggering.

4. The smart dispatching and multi-source sensing based laser hovering emergency flight traffic light system according to claim 1, wherein, The instruction scheduling unit is specifically used for: After receiving traffic status data sent by the sensing and acquisition unit, the system sequentially performs four steps: fault area determination, task unit determination, flight path calculation, and signal display parameter setting, in order to achieve scheduling and task control of the flight execution unit. In the fault area determination step, the command and dispatch unit determines whether the traffic light is in a fault state based on the traffic light status information, traffic flow information and geographic coordinate data in the traffic status data. When the traffic light status is marked as abnormal and the light intensity attenuation value exceeds the preset threshold in multiple consecutive detection cycles, the corresponding location is determined as the traffic light fault area and fault area data is generated. In the task unit determination step, the command scheduling unit selects the target unit from multiple flight execution units that maintain wireless communication with it. Based on the location information, power information and communication delay information uploaded by each flight execution unit, it calculates a comprehensive priority score. The priority score is obtained by weighting flight distance, power adequacy and communication stability. The flight execution unit with the highest score is determined as the current execution unit. In the flight path calculation step, the command scheduling unit calculates the shortest flight path under obstacle avoidance conditions based on the fault area data and the current position data of the selected current flight execution unit. The obstacle avoidance conditions include building height and no-fly zone information. The path calculation results include flight path points, altitude commands, and estimated arrival time. In the signal display parameter setting step, the command scheduling unit sets the signal display order and duration based on the traffic density information and ambient brightness parameters provided by the sensing and acquisition unit. When the traffic density is higher than the upper limit, the green light duration is extended; when the traffic density is lower than the lower limit, the red light duration is extended; and when the ambient brightness is lower than the set value, the laser display intensity is increased. The unit generates signal display control commands and sends them to the flight execution unit for execution along with the flight path data.

5. The smart dispatching and multi-source sensing based laser hovering emergency flight traffic light system according to claim 1, wherein, The laser display unit is specifically used for: After receiving the signal display control command sent by the command scheduling unit, the system sequentially executes four steps: beam parameter analysis, optical axis direction calibration, light intensity adaptive adjustment, and spot position stabilization control, in order to achieve accurate display of red, yellow, and green laser signals and road traffic indication. In the beam parameter analysis step, the laser display unit analyzes the signal display control command, extracts the color command, light intensity parameter, duration and flash frequency parameter, and generates the beam control signal based on the analysis results; In the optical axis direction calibration step, the laser display unit calculates the laser projection offset based on the attitude angle information uploaded by the flight execution unit, and corrects the beam emission direction through the built-in pitch and yaw servo adjustment mechanism to keep the beam axis consistent with the center direction of the road. In the adaptive light intensity adjustment step, the laser display unit automatically adjusts the laser output power according to the ambient brightness parameters and traffic density parameters provided by the sensing and acquisition unit. When the ambient brightness is higher than the set value, the output power is increased; when the ambient brightness is lower than the set value, the output power is reduced; and when the traffic density is higher than the threshold, the green light display duration is extended. In the spot position stabilization control step, the laser display unit uses a ground reflection detection device to monitor the spot position in real time. When the spot is detected to deviate from the target center by more than a set threshold, it automatically sends a correction command to the optical axis calibration mechanism to restore the spot position to a stable state.

6. The smart dispatching and multi-source sensing based laser hovering emergency flight traffic light system according to claim 1, wherein, The local emergency control unit is specifically used for: After detecting a communication interruption with the command and dispatch unit, four steps are executed in sequence: communication loss confirmation, emergency rule loading, traffic signal adaptive adjustment, and signal takeover recovery, in order to independently maintain the stability and continuity of traffic signal indication under the condition of communication interruption. In the communication disconnection confirmation step, the local emergency control unit confirms the communication interruption status by detecting the continuous loss of heartbeat signals of the wireless communication link. When no confirmation signal is received from the command scheduling unit within multiple consecutive detection cycles, a communication interruption flag is generated, and the hovering position, altitude information and laser display status of the current flight execution unit are recorded as pre-interruption status parameters. In the emergency rule loading step, the local emergency control unit retrieves a pre-stored emergency control rule that matches the current traffic type from the internal memory based on the communication interruption flag. The emergency control rule is automatically connected to the corresponding signal sequence based on the laser display status recorded in the pre-interruption status parameters to prevent vehicle misjudgment caused by signal abrupt changes, and generates emergency signal execution parameters. In the traffic signal adaptive adjustment step, the local emergency control unit corrects the duration of the emergency signal in real time based on the traffic flow information provided by the sensing and acquisition unit. When the traffic flow is detected to be increased compared to the previous period, the green light duration is automatically extended. When the traffic flow decreases, the yellow light transition phase is entered in advance. The laser display power is adjusted according to the lighting conditions to ensure signal visibility. The adjustment results generate signal duration correction parameters. During the signal takeover and recovery process, the local emergency control unit continuously monitors the communication link status. When it receives the communication signal from the command and dispatch unit again, it sends the current traffic status data packet to the command and dispatch unit. After the command and dispatch unit confirms the takeover, it terminates the emergency control mode and returns to the subordinate execution state.

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