Motor fault-tolerant control method for aerial work unmanned aerial vehicle

Abstract

The invention provides a motor fault-tolerant control method for a high-altitude operation unmanned aerial vehicle, and the method comprises the steps: determining a motor fault type through collecting the operation state data of a target motor, including a vibration signal, a temperature signal, a current signal, a rotating speed signal, attitude information, environment air pressure and environment wind speed; the fault types comprise rotor unbalance, current overload, thermal runaway, bearing fault and open-phase fault. And executing corresponding adjustment operation according to the fault type and the current flight state of the unmanned aerial vehicle, including: when the rotor is unbalanced, adjusting the PWM duty ratio by calculating the transverse component of the target rotating speed so as to offset the offset torque and the like. And after the adjustment operation is completed, adjusting a task execution mode according to the motor operation state, including reducing a task load or starting a landing mode, and ensuring task completion and flight safety of the unmanned aerial vehicle. According to the method, the reliability and the fault-tolerant capability of the unmanned aerial vehicle in a complex high-altitude operation environment are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a motor fault-tolerant control method for a high-altitude operation unmanned aerial vehicle. Background Art

[0002] With the rapid development of drone technology, aerial work drones are widely used in power inspection, agricultural plant protection, building monitoring and other fields. These drones usually adopt multi-rotor structures and electric drive systems, and achieve complex tasks through precise flight control technology and efficient motor drive. In the existing technology, drone motor control systems mostly rely on real-time data collection and algorithm-based operation status analysis to ensure flight stability and successful completion of the mission.

[0003] However, in actual operation, aerial drones face complex and changeable environmental conditions, such as strong winds, high temperatures, and high humidity, which place higher demands on the reliability and fault tolerance of motors. Existing technologies usually perform fault detection and response based on single sensor data, but there are still limitations in detection accuracy and response efficiency when faced with a variety of potential faults such as rotor imbalance, current overload, and thermal runaway. In addition, for mechanical and electrical problems such as bearing failures and phase failures, the fault tolerance of existing technologies is relatively limited, which may lead to mission interruption or loss of control.

[0004] Therefore, it is urgent to develop a new motor fault-tolerant control method for high-altitude UAVs. Summary of the invention

[0005] The present application provides a motor fault-tolerant control method for a high-altitude operation UAV, so as to improve the reliability and fault-tolerant capability of the UAV in a complex high-altitude operation environment.

[0006] The present application provides a motor fault-tolerant control method for a high-altitude operation UAV, comprising: Collecting the operating status data of the target motor in the aerial work drone, wherein the operating status data includes vibration signal, temperature signal, current signal, speed signal, attitude information, ambient air pressure and ambient wind speed; Determining a fault type of the target motor according to the operating status data, wherein the fault type includes rotor imbalance, current overload, thermal runaway, bearing fault, and phase loss fault; According to the fault type and the current flight state of the drone, the corresponding adjustment operation is performed; wherein, the adjustment operation includes, when a rotor imbalance is detected and the drone is flying at a high wind speed, calculating the lateral component of the target speed, adjusting the PWM duty cycle of the motor to offset the offset torque caused by the imbalance; when a current overload is detected and the drone's flight altitude exceeds a set value, reducing the power output of the target motor, and redistributing the thrust of other motors to maintain flight stability; when thermal runaway is detected and the drone's tilt angle is greater than a preset threshold, switching the target motor to an intermittent operation mode, and reducing the internal heat accumulation of the target motor by setting a fixed shutdown and startup time ratio; when a bearing fault is detected and the drone is in a long-term hovering state, reducing the speed of the target motor and adjusting the thrust output of other motors to reduce the axial load of the target motor; when a phase loss fault is detected and the drone's thrust is insufficient, reducing the load of the target motor, switching to an emergency power reduction mode, and adjusting the drone's attitude to balance the overall thrust distribution; After the adjustment operation is completed, the mission execution mode of the UAV is adjusted according to the operating state of the target motor, including reducing the high-altitude operation mission load or starting the landing mode, until the UAV mission is completed or lands safely.

[0007] Furthermore, the collecting of the operating status data of the target motor in the aerial work drone includes: The vibration sensor monitors the operating status of the target motor in real time, collects vibration signals, and records the amplitude and frequency of the vibration to analyze the balance state and mechanical operating characteristics of the motor; The temperature sensor collects the temperature signals of the target motor surface and the surrounding environment, and compares them with the safe operating temperature range of the motor to assess whether the motor has a risk of thermal runaway; Use current sensors to detect the three-phase current signals of the target motor and record the current change trend to identify current anomalies and possible electrical faults; The real-time speed signal of the target motor is obtained through the speed sensor, and the stability and change pattern of the speed are analyzed to evaluate the operating performance and mechanical loss of the motor; Combined with the attitude sensor of the drone, attitude information is collected, including roll angle, pitch angle and yaw angle, to analyze the impact of the target motor failure on the overall attitude of the drone; Environmental sensors are used to measure the ambient air pressure and wind speed in the area where the drone is located to assess the potential impact of the external environment on motor operation.

[0008] Furthermore, determining the fault type of the target motor according to the operating status data includes: Based on the collected operating status data, the vibration signal is analyzed. When the vibration amplitude exceeds the preset normal operating range and there are irregular periodic changes, it is determined to be a rotor imbalance fault; Based on the comparison between the collected current signal and the rated current range of the target motor, when the current value continues to exceed the set safety threshold and the motor power output fails to drop significantly, it is determined to be a current overload fault.

[0009] Furthermore, the determining the fault type of the target motor according to the operating status data further includes: The collected temperature signals are monitored in real time. When the temperature value of the target motor continues to rise and exceeds the set temperature upper limit, and the influence of the ambient temperature on it is eliminated, it is determined to be a thermal runaway fault; Comprehensively analyze the speed signal and vibration signal. When the speed is unstable and accompanied by low-frequency vibration characteristics, and the current signal does not exceed the normal range, it is determined to be a bearing fault. Combining the current signal and the speed signal, when the current signal shows obvious fluctuations and one phase current tends to zero, and the motor speed drops significantly, it is determined to be a phase loss fault.

[0010] Furthermore, when current overload is detected and the flight altitude of the drone exceeds a set value, the power output of the target motor is reduced, and the thrust of other motors is redistributed to maintain flight stability, including: The current value of the target motor is monitored in real time by a current sensor. When it is detected that the current value of the target motor continuously exceeds the set safety threshold, it is judged as a current overload condition; According to the reading of the drone's flight altitude sensor, confirm whether the drone's current flight altitude exceeds the set safety altitude value. If the flight altitude meets the over-altitude condition, enter the power reduction adjustment process; During the power reduction adjustment process, the power output of the target motor is gradually reduced by reducing the PWM duty cycle of the target motor, and its power is limited to a safe range to avoid overheating or damage to the motor; The flight control system calculates the available thrust of other motors in real time, and evenly distributes the thrust gap caused by the reduction of the target motor power to the remaining motors, especially the adjacent motors, to ensure the overall thrust balance of the drone. Combined with the drone's attitude sensor data, the thrust output of the remaining motors is dynamically adjusted to control the drone's pitch and roll angles to keep the drone in a stable flight state.

[0011] Furthermore, when thermal runaway is detected and the tilt angle of the drone is greater than a preset threshold, the target motor is switched to an intermittent operation mode, and the internal heat accumulation of the target motor is reduced by setting a fixed stop and start time ratio, including: The temperature of the target motor is monitored in real time by a temperature sensor. When the temperature signal shows that the temperature of the target motor continues to rise and exceeds the set safety threshold, it is confirmed that the target motor is in thermal runaway; Combined with the attitude sensor data of the drone, the pitch and roll angles of the drone are detected. When the tilt angle is greater than the preset threshold, the protection mechanism of the target motor is triggered; Enter intermittent operation mode and set the ratio of running and stopping time of the target motor to ensure that there is enough stopping time after each operation cycle to reduce the heat accumulation inside the motor; When the target motor is in intermittent operation mode, the flight control system redistributes the thrust of the remaining motors in real time to compensate for the thrust loss during the intermittent shutdown of the target motor, and adjusts the output power of other motors to keep the attitude of the drone stable; Monitor the operating status of other motors to ensure that the redistributed thrust does not cause other motors to overload or overheat, thus ensuring the safe operation of the entire UAV power system; The intermittent operation mode continues until the temperature of the target motor returns to a safe range or the drone completes the current mission and lands safely. During this process, the drone maintains a stable flight attitude and controllable flight capability.

[0012] Furthermore, when a bearing fault is detected and the UAV is in a long-term hovering state, the rotation speed of the target motor is reduced and the thrust output of other motors is adjusted to reduce the axial load of the target motor, including: The operating status of the target motor is monitored in real time through the vibration sensor and the speed sensor. When the vibration signal shows abnormal axial vibration and irregular fluctuations in speed, it is determined that the bearing of the target motor is faulty. Combined with the UAV flight control data, it is confirmed that the UAV is currently in a long-term hovering state, that is, the flight controller's altitude data and attitude data show that the UAV remains motionless at a fixed position for a time exceeding a preset threshold; Enter the adjustment process, gradually reduce the speed of the target motor and control it within the lower limit of the rated speed to reduce the mechanical stress of the bearing, while maintaining sufficient thrust output to avoid the UAV's attitude instability; The flight control system redistributes the thrust of the remaining non-faulty motors, giving priority to increasing the thrust of the motors at the diagonal position of the target motor to share the axial load of the target motor. Combined with the real-time data of the attitude sensor, the output thrust of each motor is dynamically adjusted to ensure that the pitch and roll angles of the drone remain within a stable range, thereby maintaining the overall balance of the drone while reducing the target motor load.

[0013] The beneficial effects of the technical solution provided by this application include: (1) By collecting multiple operating status data such as vibration signals, temperature signals, current signals, speed signals, attitude information, ambient air pressure and wind speed, the operating status of the motor can be fully and real-time reflected, thereby realizing accurate identification of rotor imbalance, current overload, thermal runaway, bearing fault and phase failure, and improving the accuracy and reliability of fault diagnosis. (2) According to different fault types and the current flight status of the UAV, targeted adjustment operations are adopted, such as adjusting the PWM duty cycle, intermittent operation mode and thrust redistribution, which can quickly alleviate the impact of the fault and maintain the flight stability and mission continuity of the UAV. (3) Considering the complex working conditions such as strong winds, high loads and long-term hovering often faced by high-altitude working UAVs, the method combines real-time data with fault-tolerant control of multiple fault types, significantly improving the flight reliability of the UAV in harsh environments and reducing the risk of mission interruption and flight loss of control. (4) After the adjustment operation is completed, the task execution mode is dynamically adjusted according to the motor operating status, such as reducing the task load or starting the landing mode, which can ensure the completion of the task while giving priority to ensuring the safety of the UAV, and is particularly suitable for emergency response needs in high-risk operation scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart of a motor fault-tolerant control method for a high-altitude working UAV provided in the first embodiment of the present application. DETAILED DESCRIPTION

[0015] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application, so the present application is not limited by the specific implementation disclosed below.

[0016] The first embodiment of the present application provides a motor fault-tolerant control method for a high-altitude operation UAV. Figure 1 , which is a schematic diagram of the first embodiment of the present application. Figure 1 A first embodiment of the present application provides a motor fault-tolerant control method for a high-altitude operation UAV, which is described in detail.

[0017] Step S101: collecting operating status data of a target motor in a high-altitude operation UAV, wherein the operating status data includes a vibration signal, a temperature signal, a current signal, a speed signal, attitude information, ambient air pressure, and ambient wind speed.

[0018] In step S101, the operating status data of the target motor in the aerial work drone is collected, and the hardware equipment and software algorithm are combined to ensure that the acquired data has sufficient accuracy and real-time performance. The operating status data includes vibration signals, temperature signals, current signals, speed signals, attitude information, ambient air pressure, and ambient wind speed. The specific implementation method is as follows: First, to collect vibration signals, a highly sensitive vibration sensor can be installed on the housing or fixed bracket of the target motor. The sensor collects the vibration characteristic signal of the motor in real time and transmits it to the controller through a data acquisition system with a sampling frequency of at least 1000 Hz. The vibration signal data is usually a time domain signal. For subsequent processing, it can be converted into a frequency domain signal and the key frequency components can be extracted to reflect the mechanical state of the motor.

[0019] Secondly, to collect temperature signals, thermocouples or thermistors can be installed in the winding area of ​​the motor or on the outer wall of the housing. The temperature sensor converts analog signals into digital signals and inputs real-time temperature data into the controller. When collecting temperature data, it is necessary to pay attention to the temperature changes in different areas to ensure that local overheating can be captured.

[0020] To collect current signals, Hall effect current sensors or shunt resistors are required to monitor the current signals of each phase of the target motor in real time and transmit them to the control system. The sensor must have high dynamic response characteristics to capture instantaneous current fluctuations. The collected current signal must be filtered to eliminate high-frequency noise and ensure the accuracy of the signal.

[0021] For the acquisition of speed signals, photoelectric encoders, Hall sensors or speed estimation technology based on back electromotive force can be used. Photoelectric encoders obtain speed data by recording the number of encoding pulses of the rotating shaft, and Hall sensors calculate the speed based on the change of the magnetic field in the motor. The collected data is input into the controller through a high-speed interface and linearly interpolated or smoothed.

[0022] The collection of attitude information relies on an inertial measurement unit (IMU), which usually integrates a three-axis gyroscope and a three-axis accelerometer. The collected data includes roll angle, pitch angle, yaw angle, and corresponding angular velocity. The attitude solution algorithm calculates the real-time attitude parameters of the drone and combines them with other operating status data for fault diagnosis.

[0023] The collection of ambient air pressure requires the use of a high-precision barometer. The barometer is usually installed in the flight control module of the drone to obtain the external air pressure value in real time to calculate the relative height of the drone and the change in ambient pressure. The collection of ambient wind speed requires a micro wind speed sensor, which is installed on the front or top of the drone to reduce rotor interference. The wind speed and direction data provided by the wind speed sensor are used to analyze the impact of the external environment on the motor load.

[0024] The output signals of all the above sensors are synchronously sampled through a multi-channel data acquisition card or an embedded controller. The collected operating status data is stored in the local memory and aligned according to a unified timestamp to ensure data consistency. For signals with high-frequency noise (such as current and vibration signals), a low-pass filter or fast Fourier transform (FFT) is required for preprocessing to facilitate subsequent fault analysis and control decisions.

[0025] Through the above steps, it is ensured that the collected target motor operating status data fully covers possible fault sources and provides a reliable data basis for fault judgment and adjustment operations in subsequent steps.

[0026] Furthermore, the collecting of the operating status data of the target motor in the aerial work drone includes: The vibration sensor monitors the operating status of the target motor in real time, collects vibration signals, and records the amplitude and frequency of the vibration to analyze the balance state and mechanical operating characteristics of the motor; The temperature sensor collects the temperature signals of the target motor surface and the surrounding environment, and compares them with the safe operating temperature range of the motor to assess whether the motor has a risk of thermal runaway; Use current sensors to detect the three-phase current signals of the target motor and record the current change trend to identify current anomalies and possible electrical faults; The real-time speed signal of the target motor is obtained through the speed sensor, and the stability and change pattern of the speed are analyzed to evaluate the operating performance and mechanical loss of the motor; Combined with the attitude sensor of the drone, attitude information is collected, including roll angle, pitch angle and yaw angle, to analyze the impact of the target motor failure on the overall attitude of the drone; Environmental sensors are used to measure the ambient air pressure and wind speed in the area where the drone is located to assess the potential impact of the external environment on motor operation.

[0027] First, the vibration of the target motor is monitored in real time through a vibration sensor. The vibration sensor is installed on the housing or fixed structure of the target motor to capture the vibration signal generated during the operation of the motor. The amplitude and frequency of the vibration signal are key parameters, which are used to analyze the balance state and mechanical operating characteristics of the motor. When the vibration amplitude exceeds the normal operating range or the frequency changes abnormally, it may indicate that the motor's rotor is unbalanced or other mechanical failures.

[0028] Secondly, temperature sensors are used to collect temperature signals from the target motor surface and its surroundings. These sensors are usually installed at key locations on the motor housing to ensure accurate monitoring of the motor's operating temperature. The collected temperature signal is compared with the motor's safe operating temperature range in real time. If the temperature exceeds the upper limit, it may indicate that the motor is at risk of thermal runaway. The ambient temperature signal is used to eliminate the impact of the external environment on the motor temperature, thereby more accurately determining the heat accumulation inside the motor.

[0029] The three-phase current signals of the target motor are detected in real time through current sensors. These sensors are installed in the power supply line of the motor and can capture the instantaneous value and change trend of the current. The recorded current data is used to identify possible current anomalies, such as current overload, phase failure or short circuit. When the current signal fluctuates or is unstable on a certain phase, these data provide a direct fault indication.

[0030] Speed ​​sensors are used to obtain real-time speed signals of target motors. These sensors are installed on the shaft end or other rotating parts of the motor and can continuously monitor the speed changes of the motor. By analyzing the stability and change pattern of the speed signal, the operating performance and mechanical losses of the motor can be evaluated. For example, when the speed fluctuates periodically or drops suddenly, it may indicate a bearing failure or abnormal mechanical load.

[0031] The attitude sensor is an important component in the operation of drones. It is used to collect the attitude information of drones, including roll angle, pitch angle and yaw angle. Combining this data with the operating status of the target motor, it is possible to analyze the impact of the target motor failure on the overall attitude of the drone. For example, when the vibration or thrust output of the target motor is abnormal, it may cause the attitude angle of the drone to shift, requiring further adjustment operations.

[0032] In addition, the ambient air pressure and wind speed in the area where the drone is located are measured by environmental sensors. These data are used to evaluate the potential impact of the external environment on the operation of the motor. Changes in ambient air pressure may affect the cooling effect of the motor, while changes in wind speed may cause the drone to increase the motor load under high wind speed conditions. These data provide important external parameters for analyzing the operating status of the motor.

[0033] Through the above steps, the operating status data of the target motor can be collected comprehensively and accurately. All sensor data are centrally processed by the UAV's flight control system, providing the necessary basis for subsequent fault type judgment and adjustment operations.

[0034] Step S102: determining the fault type of the target motor according to the operating status data, wherein the fault type includes rotor imbalance, current overload, thermal runaway, bearing fault and phase loss fault.

[0035] In step S102, the fault type of the target motor is determined according to the target motor operating state data collected in step S101. This step requires accurate judgment of common motor fault types such as rotor imbalance, current overload, thermal runaway, bearing fault and phase loss fault through data analysis and comparison with preset thresholds, combined with the operating characteristics of the motor. The specific implementation method is as follows.

[0036] First, frequency domain analysis methods are required for processing vibration signals. Through fast Fourier transform (FFT), the collected vibration signals are converted from the time domain to the frequency domain to extract key frequency components. If the amplitude of a certain frequency significantly exceeds the preset normal operating range, it can be preliminarily determined that the rotor is unbalanced. In addition, by analyzing the change trend of the total amplitude of the vibration signal, it can also be further verified whether there is a mechanical imbalance problem.

[0037] Secondly, the analysis of the temperature signal needs to be based on the safe temperature range of the target motor. For the winding temperature, if it exceeds the preset overheating threshold, it is judged as thermal runaway. For further confirmation, the temperature change rate can be combined to determine whether the temperature continues to rise rapidly. If the temperature rise trend does not match the operating load, further verification is performed to determine whether there is a heat dissipation abnormality.

[0038] For the processing of current signals, it is necessary to monitor the changes in the current values ​​of each phase in real time and compare them with the rated current range of the motor. When the current of a phase is significantly higher than the safety limit, it can be judged as a current overload fault. At the same time, if it is detected that the current of a phase is continuously zero or intermittent, combined with the voltage signal, it can be judged as a phase loss fault.

[0039] For the analysis of the speed signal, by comparing it with the target speed, it can be determined whether there is a deviation. If the change in speed does not conform to the input command and is consistent with the abnormal vibration signal, it can be further verified as rotor imbalance. Abnormal fluctuations in speed data may also indicate other mechanical faults, such as bearing wear.

[0040] The judgment of bearing failure needs to combine the characteristics of vibration signal and speed signal. When the high-frequency component of the vibration signal increases significantly and the speed decreases, it can be preliminarily judged as a bearing failure. In addition, by continuously monitoring the temperature signal of the bearing area, if the local temperature rises abnormally, it can also be further confirmed that the bearing is insufficiently lubricated or stuck.

[0041] In addition to combining ambient air pressure and wind speed data, the impact of the external environment on the motor's operating status must also be considered. For example, when the wind speed is high and the vibration signal fluctuates periodically, it should be analyzed to determine whether it is a dynamic imbalance caused by rotor imbalance. The analysis of environmental data can also serve as an auxiliary condition for judging current overload and thermal runaway, such as reduced heat dissipation capacity under high air pressure or increased thrust demand in strong winds.

[0042] Through the above data processing and analysis, for different fault types, the characteristics of vibration, temperature, current, speed and other signals are extracted in turn, and matched with the preset fault judgment conditions. Ultimately, the results of fault judgment will serve as the input basis for subsequent adjustment operations to ensure the accuracy and reliability of fault-tolerant control.

[0043] Furthermore, determining the fault type of the target motor according to the operating status data includes: Based on the collected operating status data, the vibration signal is analyzed. When the vibration amplitude exceeds the preset normal operating range and there are irregular periodic changes, it is determined to be a rotor imbalance fault; Based on the comparison between the collected current signal and the rated current range of the target motor, when the current value continues to exceed the set safety threshold and the motor power output fails to drop significantly, it is determined to be a current overload fault.

[0044] Furthermore, the determining the fault type of the target motor according to the operating status data further includes: The collected temperature signals are monitored in real time. When the temperature value of the target motor continues to rise and exceeds the set temperature upper limit, and the influence of the ambient temperature on it is eliminated, it is determined to be a thermal runaway fault; Comprehensively analyze the speed signal and vibration signal. When the speed is unstable and accompanied by low-frequency vibration characteristics, and the current signal does not exceed the normal range, it is determined to be a bearing fault. Combining the current signal and the speed signal, when the current signal shows obvious fluctuations and one phase current tends to zero, and the motor speed drops significantly, it is determined to be a phase loss fault.

[0045] When determining a rotor imbalance fault, the vibration signal collected by the vibration sensor is first analyzed. By comparing the vibration amplitude with the preset normal operating range, it is possible to preliminarily determine whether the motor is abnormal. If the vibration amplitude exceeds the normal range and is accompanied by irregular periodic changes, this indicates that the rotor may be unbalanced. Imbalance may be caused by mass deviation or loose installation on the rotor. Such vibration characteristics provide a clear basis for diagnosing rotor imbalance.

[0046] For current overload faults, the three-phase current signal of the target motor is monitored in real time through the current sensor and compared with the rated current range of the target motor. When the current value continues to exceed the set safety threshold and the motor power output does not drop significantly, it can be judged as a current overload fault. This situation usually occurs when the load is too large or the circuit is abnormal. It is necessary to pay attention to the change trend of the current to avoid overheating or damage to the motor due to current overload.

[0047] Real-time monitoring of temperature signals is critical when determining thermal runaway faults. When the temperature value of the target motor continues to rise and exceeds the set temperature upper limit, the influence of ambient temperature on the motor needs to be eliminated. If the ambient temperature is low and the motor temperature continues to rise, it can be judged as a thermal runaway fault. This fault is usually related to the obstruction of heat dissipation inside the motor or abnormal operation, which may cause permanent damage to the motor, so quick action is required.

[0048] The judgment of bearing failure requires a comprehensive analysis of the speed signal and vibration signal. When the speed signal shows instability and is accompanied by low-frequency vibration characteristics, and the current signal does not exceed the normal range, it can be determined as a bearing failure. This situation indicates that the bearing may have wear, insufficient lubrication or other mechanical problems, resulting in abnormal vibration and speed fluctuations when the motor is running.

[0049] In judging the phase failure, it is necessary to analyze the current signal and the speed signal. When the current signal shows obvious fluctuations and the current of a phase tends to zero, and the motor speed drops significantly, it can be determined as a phase failure. This fault is usually caused by a circuit breaker or loose connection of a phase of the motor power supply line, which directly affects the stable operation of the motor.

[0050] By describing the judgment methods of the above five fault types in detail, each judgment method is based on specific sensor data and analyzed in combination with the actual operating status of the UAV. This comprehensive analysis method ensures the accuracy and real-time nature of fault identification and provides a reliable basis for the fault-tolerant control of the UAV's motor.

[0051] Step S103: Execute corresponding adjustment operations according to the fault type and the current flight state of the drone; wherein the adjustment operations include, when a rotor imbalance is detected and the drone is flying at a high wind speed, calculating the lateral component of the target speed, and adjusting the PWM duty cycle of the motor to offset the offset torque caused by the imbalance; when a current overload is detected and the drone's flight altitude exceeds a set value, reducing the power output of the target motor, and redistributing the thrust of other motors to maintain flight stability; when thermal runaway is detected and the drone's tilt angle is greater than a preset threshold, switching the target motor to an intermittent operation mode, and reducing the internal heat accumulation of the target motor by setting a fixed shutdown and startup time ratio; when a bearing fault is detected and the drone is in a long-term hovering state, reducing the speed of the target motor and adjusting the thrust output of other motors to reduce the axial load of the target motor; when a phase loss fault is detected and the drone's thrust is insufficient, reducing the load of the target motor, switching to an emergency power reduction mode, and adjusting the drone's attitude to balance the overall thrust distribution.

[0052] In step S103, the corresponding adjustment operation is performed according to the fault type of the target motor and the current flight state of the drone. The adjustment operation aims to alleviate the impact of the fault on the flight performance and ensure the stable operation of the drone by reasonably adjusting the operating parameters of the target motor and the overall flight attitude of the drone.

[0053] When rotor imbalance is detected and the drone is in high wind speed flight, it is necessary to first calculate the lateral component of the target motor speed to evaluate the offset torque caused by the imbalance. By establishing a dynamic model of the target motor, the asymmetric distribution effect of speed changes on the rotor aerodynamic force can be calculated. After the offset torque is obtained, the PWM duty cycle of the target motor is adjusted to gradually reduce the dynamic imbalance caused by the imbalance so that the motor output torque is balanced with the thrust of other motors again. This adjustment operation requires real-time monitoring of the changes in the vibration signal to ensure that the impact of the imbalance is effectively suppressed.

[0054] When a current overload is detected and the drone's flight altitude exceeds a set value, the power output of the target motor needs to be reduced immediately. This can be achieved by limiting the input current of the motor while monitoring whether the motor output power is below a preset safety threshold. While reducing the output of the target motor, the overall thrust distribution strategy of the drone needs to be recalculated, and the thrust output of other motors needs to be appropriately increased to compensate for the insufficient power of the target motor and ensure flight stability and altitude maintenance. The thrust distribution adjustment needs to be performed dynamically based on the real-time attitude data and altitude information in the flight control system.

[0055] When thermal runaway is detected and the tilt angle of the drone is greater than the preset threshold, the target motor should be immediately switched to intermittent operation mode. This mode controls the operating cycle of the target motor by setting a fixed ratio of stop and start time, thereby reducing its heat accumulation. To ensure that the thermal runaway problem is alleviated, the parameter setting of the intermittent operation mode needs to be based on the real-time temperature signal of the target motor and the mission load. At the same time, the flight control system needs to adjust the drone's attitude to avoid flight instability caused by the intermittent operation of the target motor.

[0056] When a bearing failure is detected and the drone is in a long-term hovering state, such as a hovering time exceeding a predetermined time, the speed of the target motor should be reduced to reduce the mechanical load on the bearing. At the same time, the thrust output of other motors should be appropriately adjusted to ensure that the drone's hovering attitude is stable. In the case of a bearing failure, the vibration signal and the speed change of the target motor need to be continuously monitored to assess the risk of further wear of the bearing. If necessary, the adjustment operation can trigger a change in the mission priority to reduce dependence on the target motor.

[0057] When a phase loss fault is detected and the drone has insufficient thrust, the load of the target motor should be reduced to limit its power output to avoid further failures caused by the phase loss. At the same time, the target motor is switched to emergency power reduction mode to reduce excessive reliance on the missing phase. To maintain the flight stability of the drone, the attitude parameters of the drone need to be adjusted through the flight control system, and the thrust output of the remaining motors needs to be redistributed to balance the overall power distribution. In addition, combined with the attitude information and the current flight altitude, the backup landing mode can be activated to ensure the safety of the drone.

[0058] Through the above operations, differentiated adjustment strategies are adopted for different fault types, making full use of the operating status data and the control capabilities of the flight control system to make the fault-tolerant control process of the target motor efficient and feasible.

[0059] Specific examples are provided below for each fault type: When a rotor imbalance is detected and the drone is flying at high wind speeds, it is necessary to adjust the operating state of the target motor to offset the offset torque caused by the imbalance. The specific operation is to use the vibration signal of the target motor to determine the direction of the imbalance, and then reduce its output thrust by appropriately reducing the PWM duty cycle of the target motor. For example, if the right motor vibrates too much, causing the drone to deviate to one side, the thrust of this motor can be reduced while increasing the thrust of the adjacent motor to balance the attitude. After the operation is completed, the attitude changes of the drone are monitored through the flight control system to ensure that the vibration is reduced and the flight direction of the drone remains stable.

[0060] When a current overload is detected and the flight altitude of the drone exceeds the set value, the power output of the target motor needs to be quickly reduced to prevent overheating or further damage. The specific implementation method is to monitor the real-time current value of the motor, and when it is found that it exceeds the set safety current threshold, the PWM duty cycle of the target motor is gradually reduced. For example, if the current of the left front motor is overloaded, its power can be reduced to 70% of normal operation. At the same time, the flight control system allocates more thrust to the remaining motors, especially the right rear motor to balance the attitude of the drone. After adjustment, monitor again whether the current has returned to a safe range.

[0061] When thermal runaway is detected and the tilt angle of the drone is greater than a preset threshold, it is necessary to reduce the heat accumulation of the target motor through an intermittent operation mode. Specifically, the target motor is set to a fixed start-up and shutdown cycle, such as running for 2 seconds and stopping for 1 second. During each operation cycle, the load of the target motor is reduced to further reduce heat generation. At the same time, in order to compensate for the impact caused by the reduction in thrust of the target motor, the thrust of other motors will increase accordingly. For example, when the right motor has thermal runaway, the thrust of the left motor and the rear motor is gradually increased to maintain the balance of the drone.

[0062] When a bearing failure is detected and the drone is in a long-term hovering state, the speed of the target motor needs to be reduced to reduce the mechanical stress of the bearing. The specific operation is to monitor the current speed of the target motor through the speed sensor, and then limit its speed to 70%-80% of the rated speed. At the same time, the thrust of the remaining motors is redistributed to maintain the stable hover of the drone. For example, if the target motor is located in the right front of the drone, after its speed is reduced, the left and right rear motors can increase thrust to balance the load, and adjust the attitude parameters in real time through the flight control system to prevent the drone from tilting.

[0063] When a phase loss fault is detected and the drone has insufficient thrust, it is necessary to reduce the load of the target motor and switch to the emergency power reduction mode, while adjusting the attitude to balance the overall thrust distribution. The specific operation is to calculate the power reduction ratio based on the remaining working phases of the motor, and then reduce the PWM duty cycle of the target motor to that ratio. For example, when only two phases of a three-phase motor are working, its output power is reduced to 2 / 3 of normal operation. At the same time, the thrust of the remaining non-faulty motors is adjusted in real time through the flight control system, such as increasing the thrust of the diagonal motor to compensate for the deficiency of the target motor, to ensure that the flight direction and altitude of the drone remain stable.

[0064] The implementation of each adjustment operation requires real-time analysis of the target motor's operating data, dynamic adjustment of its operating parameters, and reallocation of the thrust of other motors through the flight control system, ultimately achieving effective fault-tolerant control of UAV failures.

[0065] Furthermore, when current overload is detected and the flight altitude of the drone exceeds a set value, the power output of the target motor is reduced, and the thrust of other motors is redistributed to maintain flight stability, including: The current value of the target motor is monitored in real time by a current sensor. When it is detected that the current value of the target motor continuously exceeds the set safety threshold, it is judged as a current overload condition; According to the reading of the drone's flight altitude sensor, confirm whether the drone's current flight altitude exceeds the set safety altitude value. If the flight altitude meets the over-altitude condition, enter the power reduction adjustment process; During the power reduction adjustment process, the power output of the target motor is gradually reduced by reducing the PWM duty cycle of the target motor, and its power is limited to a safe range to avoid overheating or damage to the motor; The flight control system calculates the available thrust of other motors in real time, and evenly distributes the thrust gap caused by the reduction of the target motor power to the remaining motors, especially the adjacent motors, to ensure the overall thrust balance of the drone. Combined with the drone's attitude sensor data, the thrust output of the remaining motors is dynamically adjusted to control the drone's pitch and roll angles to keep the drone in a stable flight state.

[0066] First, the current value of the target motor is monitored in real time by the current sensor installed on it. The current sensor captures the instantaneous current data of the motor when it is running and compares it with the pre-set safety current threshold. If the current value of the target motor continues to exceed the safety threshold and does not show a clear trend of falling back, it is judged as a current overload condition. This overload may be caused by high load, winding overheating or circuit abnormality, and immediate measures need to be taken to prevent motor damage.

[0067] After confirming the current overload, the current altitude data of the drone is obtained through the flight altitude sensor. The flight altitude sensor can measure the flight altitude of the drone through air pressure, GPS or laser ranging. When the altitude data exceeds the pre-set safe flight altitude value, it means that the drone is in a high-altitude flight state, and the risk of current overload may increase. For this reason, the system enters the power reduction adjustment process to protect the target motor and maintain the stable flight of the drone.

[0068] During the power reduction adjustment process, the target motor's power output is gradually reduced by reducing its PWM duty cycle. The reduction of the PWM duty cycle directly reduces the motor's input power, thereby limiting its output power to a safe range. The adjustment process needs to be carried out gradually to avoid sudden effects on the drone's overall thrust balance. By controlling the target motor's power output, its current load can be effectively reduced while avoiding overheating or permanent damage to the motor windings due to overload.

[0069] As the target motor power decreases, the flight control system needs to calculate the gap caused by the thrust reduction in real time and evenly distribute the thrust gap to other motors, especially the motors adjacent to the target motor. This process is based on the real-time operating data of other motors and the current thrust requirements. The flight control system dynamically adjusts the thrust output of these motors to ensure that the total thrust of the drone can maintain the stability required for flight.

[0070] At the same time, the overall flight status is monitored through the attitude sensor data of the drone, including changes in pitch, roll and yaw angles. If the thrust distribution process causes attitude deviation, the system will dynamically adjust the output thrust of other motors to balance the attitude of the drone and restore its normal flight state. For example, when the target motor is located in the right front of the drone and its power is reduced, the system can increase the thrust of the left and right rear motors to keep the pitch and roll angles stable.

[0071] Furthermore, when thermal runaway is detected and the tilt angle of the drone is greater than a preset threshold, the target motor is switched to an intermittent operation mode, and the internal heat accumulation of the target motor is reduced by setting a fixed stop and start time ratio, including: The temperature of the target motor is monitored in real time by a temperature sensor. When the temperature signal shows that the temperature of the target motor continues to rise and exceeds the set safety threshold, it is confirmed that the target motor is in thermal runaway; Combined with the attitude sensor data of the drone, the pitch and roll angles of the drone are detected. When the tilt angle is greater than the preset threshold, the protection mechanism of the target motor is triggered; Enter intermittent operation mode and set the ratio of running and stopping time of the target motor to ensure that there is enough stopping time after each operation cycle to reduce the heat accumulation inside the motor; When the target motor is in intermittent operation mode, the flight control system redistributes the thrust of the remaining motors in real time to compensate for the thrust loss during the intermittent shutdown of the target motor, and adjusts the output power of other motors to keep the attitude of the drone stable; Monitor the operating status of other motors to ensure that the redistributed thrust does not cause other motors to overload or overheat, thus ensuring the safe operation of the entire UAV power system; The intermittent operation mode continues until the temperature of the target motor returns to a safe range or the drone completes the current mission and lands safely. During this process, the drone maintains a stable flight attitude and controllable flight capability.

[0072] First, the temperature of the target motor is monitored in real time through a temperature sensor. Temperature sensors are usually installed in key parts of the motor, such as the casing or near the windings, to capture temperature changes during operation. When the temperature signal shows that the temperature of the target motor continues to rise and exceeds the preset safety threshold, it can be confirmed that the target motor is in thermal runaway. The occurrence of thermal runaway may be caused by continuous high-load operation, insufficient cooling, or other internal problems, which need to be handled in a timely manner to prevent motor damage or failure.

[0073] Combined with the attitude sensor data of the drone, the current pitch and roll angles of the drone are detected. When the tilt angle of the drone is detected to exceed the preset safety threshold, this indicates that the attitude of the drone may have been affected by the abnormal operation of the target motor. In this case, the protection mechanism of the target motor is immediately triggered to avoid further heat accumulation and attitude loss of control by adjusting the operation mode.

[0074] After the target motor switches to intermittent operation mode, the system will operate according to the preset ratio of running and stopping time. The purpose of the intermittent operation mode is to set enough stopping time after each operation cycle so that the heat inside the motor can be naturally dissipated, thereby reducing the overall temperature of the motor. This method can not only maintain a certain thrust output, but also effectively control the heat accumulation of the motor to prevent its temperature from continuing to rise during continuous operation.

[0075] When the target motor enters the intermittent operation mode, the flight control system will reallocate the thrust of other motors in real time to compensate for the loss of thrust caused by the shutdown of the target motor. Thrust redistribution needs to be dynamically adjusted according to the current attitude and flight mission of the drone. In particular, the thrust of the motor relative to the target motor may need to be increased appropriately to maintain the overall flight balance. In addition, the flight control system will also monitor the operating status of other motors to ensure that the reallocated thrust does not cause non-fault motors to overload or overheat, thereby ensuring the safe operation of the entire drone power system.

[0076] The intermittent operation mode will continue until the temperature of the target motor returns to a safe range or the drone completes the current mission and lands safely. During this process, the drone needs to maintain a stable flight attitude and be able to dynamically adjust flight parameters according to actual conditions. If the mission priority is high and environmental conditions permit, the system will prioritize completing the mission and ensure a safe landing. If the thermal runaway problem is serious, the system will start the landing procedure in advance to protect the target motor and the drone as a whole.

[0077] Every step in this process requires real-time monitoring and dynamic adjustment to ensure the safety and reliability of drones in complex operating environments.

[0078] Furthermore, when a bearing fault is detected and the UAV is in a long-term hovering state, the rotation speed of the target motor is reduced and the thrust output of other motors is adjusted to reduce the axial load of the target motor, including: The operating status of the target motor is monitored in real time through the vibration sensor and the speed sensor. When the vibration signal shows abnormal axial vibration and irregular fluctuations in speed, it is determined that the bearing of the target motor is faulty. Combined with the UAV flight control data, it is confirmed that the UAV is currently in a long-term hovering state, that is, the flight controller's altitude data and attitude data show that the UAV remains motionless at a fixed position for a time exceeding a preset threshold; Enter the adjustment process, gradually reduce the speed of the target motor and control it within the lower limit of the rated speed to reduce the mechanical stress of the bearing, while maintaining sufficient thrust output to avoid the UAV's attitude instability; The flight control system redistributes the thrust of the remaining non-faulty motors, giving priority to increasing the thrust of the motors at the diagonal position of the target motor to share the axial load of the target motor. Combined with the real-time data of the attitude sensor, the output thrust of each motor is dynamically adjusted to ensure that the pitch and roll angles of the drone remain within a stable range, thereby maintaining the overall balance of the drone while reducing the target motor load.

[0079] First, the operating status of the target motor is monitored in real time through vibration sensors and speed sensors. The vibration sensor is installed on the motor housing or related components to detect the axial vibration signal of the motor during operation. When the vibration signal shows abnormality and exceeds the normal operating range, and the speed sensor detects irregular fluctuation characteristics, it can be determined that the bearing of the target motor is faulty. This fault is usually caused by bearing wear, insufficient lubrication or abnormal mechanical force, which may lead to reduced motor operating efficiency or more serious mechanical damage.

[0080] After confirming the bearing failure of the target motor, the flight control data of the drone is used to determine whether the current flight state is a long-term hovering state. The altitude sensor and attitude sensor of the flight control system can provide the position and attitude information of the drone in real time. When these data indicate that the drone has been hovering in a fixed position for a period of time exceeding the preset safety threshold, it is confirmed that the drone is in a long-term hovering state. In this case, the bearing load of the target motor may continue to increase, and adjustment measures need to be taken immediately to protect the motor.

[0081] The adjustment process starts with gradually reducing the speed of the target motor. The power output of the target motor is controlled by the flight control system, and its speed is adjusted to the lower limit of the rated speed. Reducing the speed can effectively reduce the mechanical stress of the bearing, thereby reducing the wear of the bearing. However, while reducing the speed, it is necessary to ensure that the target motor still maintains sufficient thrust output to avoid unstable attitude of the drone due to insufficient thrust.

[0082] To compensate for the reduction in thrust of the target motor, the flight control system reallocates the thrust of the remaining non-faulty motors in real time, giving priority to increasing the thrust output of the motors diagonally opposite to the target motor. This can share the axial load of the target motor while maintaining the overall balance of the drone through reasonable thrust distribution. For other non-faulty motors, the system dynamically adjusts their thrust output to adapt to new flight requirements.

[0083] Combined with the real-time data from the attitude sensor, the system monitors and adjusts the pitch and roll angles of the drone. By precisely controlling the thrust distribution of each motor, the attitude of the drone can be kept within a safe and stable range. Even when the target motor load is reduced, the drone can continue to perform hovering tasks or other flight operations without losing attitude control due to uneven thrust distribution.

[0084] The entire adjustment process requires real-time monitoring of the operating status of the target motor and other motors to ensure that the adjusted thrust distribution does not cause overload of non-fault motors or overall instability of the drone.

[0085] Furthermore, when the rotor imbalance is detected and the UAV is flying at a high wind speed, the lateral component of the target speed is calculated, and the PWM duty cycle of the motor is adjusted to offset the offset torque caused by the imbalance, including: According to the following formula 1, the lateral component of the target motor speed is calculated: ; in, Represents the lateral component of the target motor in radians per second (rad / s). It represents the contribution of vibration to the rotation speed in the lateral direction.

[0086] Indicates The mass of the vibrating mass points, in kilograms (kg). These mass points usually correspond to the distributed mass on the rotor and can be measured by mass detection equipment. The recommended value range is 0.1–10 kg.

[0087] Indicates The angular velocity corresponding to the vibration frequency of each vibrating mass point is expressed in radians per second (rad / s). This is calculated by converting the frequency value collected by the vibration sensor.

[0088] For the The vibration phase angle of each vibrating mass point is in radians (rad). It describes the phase distribution of the vibration on the rotor and can be obtained by analyzing the vibration waveform.

[0089] The roll angle of the drone is in radians (rad). This angle is provided by the attitude sensor in real time.

[0090] Indicates the total number of mass points involved in the vibration analysis, which is determined by the granularity of the vibration analysis and is usually 4 to 12.

[0091] According to the following formula 2, the additional offset torque caused by rotor imbalance is calculated: : ; in, represents the additional offset moment; is the ambient wind speed, measured by the sensor; For reference wind speed, it is determined according to the specifications provided by the drone manufacturer; Indicates The distance from the vibration mass point to the rotation axis is determined by the mechanical design parameters, and the recommended value range is 0.05–0.5 m.

[0092] The lateral correction moment is calculated according to the following formula 3: ; in, represents the correction torque; is the roll angle of the drone; is the yaw angle of the drone, provided by the attitude sensor in real time.

[0093] The PWM duty cycle of the target motor is calculated by the following formula 4: : ; in, is the equivalent resistance of the target motor in ohms. It is provided by the motor design parameters.

[0094] is the motor torque constant in Newton meters per ampere (N·m / A), which is determined by the motor characteristics.

[0095] is the battery voltage of the target motor, which is determined by the battery characteristics.

[0096] Through the above calculations, the lateral component, offset torque and correction torque of the target motor are gradually solved, and finally the PWM duty cycle of the motor is dynamically adjusted according to the correction torque to ensure that the UAV maintains a stable posture when flying at high wind speeds.

[0097] Furthermore, when a phase failure is detected and the thrust of the drone is insufficient, the load of the target motor is reduced, the emergency power reduction mode is switched, and the attitude of the drone is adjusted to balance the overall thrust distribution, including: According to the following formula 5, calculate the power factor of the target motor : ; in, Indicates the number of remaining working phases of the current target motor, which is determined by detecting the number of normally working phases in the current signal, usually 1 to 2 (for three-phase motors).

[0098] Indicates the number of complete working phases of the target motor, and the design value is 3 (for a three-phase motor).

[0099] Indicates the additional offset torque caused by a phase failure. It is calculated based on the dynamic characteristics of the motor and the recommended range is 0 to 50 N·m.

[0100] Indicates the maximum allowable torque of the target motor, provided by the motor manufacturer.

[0101] According to the following formula 6, calculate the PWM duty cycle of the target motor: ; in, Indicates the original PWM duty cycle of the target motor, which is set by the flight control system according to mission requirements. The recommended range is 0 to 100%.

[0102] Indicates the adjusted PWM duty cycle; According to the following formula 7, calculate the drone attitude correction factor : ; in, Indicates the total thrust requirement of the UAV, which is calculated by the flight control system based on the current flight conditions and load of the UAV. The recommended range is 50 to 1000 N.

[0103] is the current roll angle of the drone, is the current pitch angle of the drone, measured by the attitude sensor.

[0104] Indicates the remaining working phases of the current target motor; Indicates the number of complete working phases of the target motor; The adjusted thrust of the target motor is calculated according to the following formula 8: ; in, is the adjusted target motor thrust; is the original target motor thrust, set by the flight control system.

[0105] is the power factor of the target motor, calculated by formula 5; The remaining motor thrust is calculated according to Formula 9 below: ; in, After redistribution Thrust of a non-faulty motor; Before adjustment The thrust of a non-faulty motor is usually determined based on the real-time operating data provided by the UAV's flight control system.

[0106] is the attitude correction factor; is the number of non-faulty motors currently available.

[0107] By evenly distributing the correction factor to the non-faulty motors, the thrust gap is compensated while maintaining the overall attitude stability of the drone.

[0108] When a phase failure is detected in the target motor and the drone is confirmed to have insufficient thrust, a series of adjustments need to be made through the flight control system to ensure that the drone can continue to fly stably and complete the mission. The following are the specific steps for adjusting thrust and attitude correction: First, after calculating the adjusted thrust of the target motor, the flight control system will convert this adjustment result into the operating parameters of the motor. Specifically, by reducing the PWM duty cycle or input current of the target motor, its load and output thrust are directly reduced. This can limit the operating ability of the target motor to a safe range under its fault condition, preventing further damage to the motor or affecting other components.

[0109] For other non-faulty motors, the flight control system will adjust the output thrust of these motors one by one according to the reallocated thrust requirements. The specific operation includes sending new instructions to the electronic speed controllers (ESC) of these motors to increase or decrease their PWM duty cycle, so that their thrust increases or decreases to the new set value. In particular, for the motors that are opposite to the target motor position, their thrust usually needs to be appropriately increased to make up for the gap caused by insufficient thrust of the target motor.

[0110] After completing the thrust adjustment, the flight control system monitors the attitude changes of the drone in real time through attitude sensors (such as accelerometers and gyroscopes), including roll angle, pitch angle, and yaw angle. If the attitude deviates from the safe range, such as the roll angle of the drone tilting toward the side where the target motor is located, the flight control system will dynamically adjust the thrust of other motors to correct the attitude deviation. For example, when the right side of the drone tilts downward, the thrust of the left motor can be increased while the thrust of the right motor can be reduced to restore the drone to a horizontal state.

[0111] The flight control system also continuously monitors the operating status of all motors to ensure that thrust adjustments do not cause non-faulty motors to overload or increase their temperature beyond a safe range. If a non-faulty motor approaches its load limit due to the increased thrust from the redistribution, the flight control system will further optimize the thrust distribution strategy to distribute the excess thrust demand to other non-faulty motors.

[0112] The entire adjustment process is dynamic and combined with the UAV's flight mission and environmental conditions. For example, in high wind conditions, the motor on the windward side may need additional thrust, while the thrust of the motor on the leeward side may need to be appropriately reduced to maintain the stability of the UAV. The flight control system continuously optimizes the distribution of motor thrust based on real-time wind speed data and the UAV's attitude information.

[0113] If the target motor continues to deteriorate or the load of other motors is close to the limit during the adjustment process, the flight control system will automatically start the drone's landing mode. In landing mode, the load of the target motor is further reduced, and other motors are coordinated to slow down, so that the drone can land smoothly in a safe area.

[0114] Step S104: After the adjustment operation is completed, the task execution mode of the UAV is adjusted according to the operating state of the target motor, including reducing the high-altitude operation task load or starting the landing mode, until the UAV mission is completed or lands safely.

[0115] In step S104, after the adjustment operation is completed, the task execution mode of the UAV is adjusted according to the operating state of the target motor. The adjustment process requires a comprehensive analysis of the real-time operating capability of the target motor and the current task requirements of the UAV to ensure the smooth completion of the flight mission or the safe landing of the UAV.

[0116] First, the remaining performance parameters of the motor are evaluated based on the operating status data of the target motor, including speed, current, vibration, temperature and other information. If the motor speed can be stably maintained within the mission requirements, and the vibration signal and temperature signal do not exceed the preset safety threshold, it can be determined that the target motor has been restored to a usable state and there is no need to further reduce the mission load. However, if it is detected that the performance of the target motor has significantly decreased, such as large speed fluctuations, continuous abnormal current, or high-amplitude characteristics of the vibration signal, it is necessary to reduce the high-altitude operation mission load of the drone. This can be achieved by adjusting the flight path of the drone, reducing the work intensity, or shortening the mission time, thereby reducing the working pressure of the target motor and extending its operating life.

[0117] When the operating status of the target motor shows that it cannot be restored to an acceptable range, such as continued high temperature, phase loss or other difficult-to-correct faults, the landing mode should be activated as a priority. In landing mode, the flight control system first selects a suitable landing point and path based on the current environmental conditions (including air pressure, wind speed, etc.). To ensure the safety of the landing process, the thrust distribution of other motors needs to be dynamically adjusted to maintain the stability of the drone's attitude. During the descent, the status data of the target motor needs to be continuously monitored to ensure that it does not further increase the risk of instability of the drone. At the same time, according to the real-time flight altitude and drone attitude, the power output of the target motor is gradually reduced to prevent the excess torque generated by the faulty motor from affecting the landing trajectory.

[0118] If the target motor failure occurs in the middle or later stages of the mission and the drone is close to the mission target area, the flight control system can adjust the mission priority to complete the remaining mission while ensuring that the target motor is not overloaded. At this time, it is necessary to appropriately reduce the energy consumption of other non-essential mission modules, such as shutting down some auxiliary equipment or limiting unnecessary attitude adjustments, so as to concentrate limited power resources on the main mission.

[0119] During the entire adjustment process, the system needs to combine the real-time status data of the target motor with the flight status parameters of the drone (such as attitude angle, thrust distribution, etc.) to dynamically optimize the task execution strategy. Between the load adjustment of the high-altitude operation task and the landing mode switch, the system needs to make the best choice based on the real-time analysis results to ensure that both the task completion requirements are met and the overall safety of the drone is guaranteed. The implementation of this step can effectively deal with the impact of the failure of the target motor on the drone mission and ensure flight safety and mission integrity in extreme situations.

[0120] Furthermore, after the adjustment operation is completed, the task execution mode of the UAV is adjusted according to the operating state of the target motor, including reducing the high-altitude operation task load or starting the landing mode, until the UAV task is completed or landed safely, including: The remaining performance of the target motor is evaluated in real time through its operating status data, including the current power output capacity, speed stability, and temperature change trend, to determine whether the target motor can continue to support the current high-altitude operation task; When the evaluation results show that the remaining performance of the target motor is insufficient to complete the current task, the load of the aerial work task is immediately reduced; Combined with the flight control data of the UAV, it determines whether the current environmental conditions are suitable for continuous flight. If the environmental conditions are unfavorable or the operating status of the target motor deteriorates further, the landing mode is initiated; When the landing mode is activated, the drone's landing path is planned to the nearest safe area first, and the drone's stable descent posture is maintained by adjusting the thrust distribution of other motors, and the flight altitude is gradually reduced; During the landing process, the status of the target motor and other motors is monitored in real time, and the thrust output and attitude of the drone are dynamically adjusted to ensure the safety and controllability of the landing process.

[0121] First, the remaining performance of the target motor is evaluated in real time through its operating status data. These data include the motor's current power output capacity, speed stability, and temperature change trend. The power output capacity is calculated through the actual current, voltage, and motor torque characteristics measured by the flight control system to evaluate whether the target motor can maintain its normal operation. The stability of the speed is monitored through the real-time readings of the speed sensor. If there are frequent fluctuations or significant drops, it indicates that the target motor may have lost the ability to output stably. The temperature change trend is provided by the temperature sensor, and the continued increase in temperature indicates that the motor may be at risk of overheating. Combining these indicators, the flight control system can accurately determine whether the target motor can continue to support the current high-altitude operation mission.

[0122] If the evaluation results show that the remaining performance of the target motor is insufficient to complete the current task, the flight control system will immediately take measures to reduce the load of the high-altitude operation task. For example, for a drone carrying supplies, the flight load can be reduced by releasing some of the cargo; for a drone that is continuously conducting inspections, the flight time can be reduced by reducing the mission scope. This load reduction strategy is designed to reduce the working pressure of the target motor while alleviating the compensation burden of other non-faulty motors.

[0123] Combined with the real-time flight control data of the flight control system, it determines whether the current environmental conditions are suitable for the drone to continue flying. If environmental conditions such as strong winds, low air pressure or high temperatures have an adverse effect on flight, or the operating status of the target motor deteriorates further, such as a sharp increase in temperature or a sharp drop in output power, the flight control system will immediately activate the landing mode to ensure the safety of the drone.

[0124] When the landing mode is activated, the flight control system will prioritize the drone's landing path to the nearest safe area, such as a flat open space or an unmanned operation area. The landing path planning combines the drone's current position, altitude, and obstacle distribution, and ensures the safety of the landing process through a path optimization algorithm. During the landing process, the drone's stable attitude is maintained by adjusting the thrust distribution of non-faulty motors. In particular, the thrust of the target motor will be further reduced to reduce the mechanical load, while the thrust distribution of other motors is dynamically adjusted according to the real-time data of the attitude sensor to ensure that the drone's roll angle and pitch angle remain within a stable range during the descent.

[0125] As the drone gradually decreases its flight altitude, the flight control system continuously monitors the operating status of the target motor and other motors in real time. If an abnormal operating status of a non-faulty motor is found, such as excessive current or increased temperature, the system will further optimize the thrust distribution to avoid the drone's attitude being out of control due to a single motor failure. Through this dynamic adjustment, the drone can maintain a stable flight attitude and a controllable descent speed throughout the landing process.

[0126] Finally, after the drone successfully lands, the flight control system will completely stop the operation of the target motor to protect it from further damage, and record the fault and operation data for subsequent analysis.

[0127] A second embodiment of the present application provides an electronic device, the electronic device comprising: processor; The memory is used to store a program. When the program is read and executed by the processor, it executes a motor fault-tolerant control method for a high-altitude working drone provided in the first embodiment of the present application.

[0128] The third embodiment of the present application provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, a motor fault-tolerant control method for a high-altitude working drone provided in the first embodiment of the present application is executed.

[0129] Although the present application is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present application. Any technical personnel in this field may make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims of the present application.

Claims

1. A motor fault-tolerant control method for a high-altitude operation UAV, characterized in that: include: Collecting the operating status data of the target motor in the aerial work drone, wherein the operating status data includes vibration signal, temperature signal, current signal, speed signal, attitude information, ambient air pressure and ambient wind speed; Determining a fault type of the target motor according to the operating status data, wherein the fault type includes rotor imbalance, current overload, thermal runaway, bearing fault, and phase loss fault; According to the fault type and the current flight state of the drone, the corresponding adjustment operation is performed; wherein, the adjustment operation includes, when a rotor imbalance is detected and the drone is flying at a high wind speed, calculating the lateral component of the target speed, adjusting the PWM duty cycle of the motor to offset the offset torque caused by the imbalance; when a current overload is detected and the drone's flight altitude exceeds a set value, reducing the power output of the target motor, and redistributing the thrust of other motors to maintain flight stability; when thermal runaway is detected and the drone's tilt angle is greater than a preset threshold, switching the target motor to an intermittent operation mode, and reducing the internal heat accumulation of the target motor by setting a fixed shutdown and startup time ratio; when a bearing fault is detected and the drone is in a long-term hovering state, reducing the speed of the target motor and adjusting the thrust output of other motors to reduce the axial load of the target motor; when a phase loss fault is detected and the drone's thrust is insufficient, reducing the load of the target motor, switching to an emergency power reduction mode, and adjusting the drone's attitude to balance the overall thrust distribution; After the adjustment operation is completed, the mission execution mode of the UAV is adjusted according to the operating state of the target motor, including reducing the high-altitude operation mission load or starting the landing mode, until the UAV mission is completed or lands safely.

2. The motor fault-tolerant control method for a high-altitude working UAV according to claim 1 is characterized in that: The collecting of the operating status data of the target motor in the aerial work drone includes: The vibration sensor monitors the operating status of the target motor in real time, collects vibration signals, and records the amplitude and frequency of the vibration to analyze the balance state and mechanical operating characteristics of the motor; The temperature sensor collects the temperature signals of the target motor surface and the surrounding environment, and compares them with the safe operating temperature range of the motor to assess whether the motor has a risk of thermal runaway; Use current sensors to detect the three-phase current signals of the target motor and record the current change trend to identify current anomalies and possible electrical faults; The real-time speed signal of the target motor is obtained through the speed sensor, and the stability and change pattern of the speed are analyzed to evaluate the operating performance and mechanical loss of the motor; Combined with the attitude sensor of the drone, attitude information is collected, including roll angle, pitch angle and yaw angle, to analyze the impact of the target motor failure on the overall attitude of the drone; Environmental sensors are used to measure the ambient air pressure and wind speed in the area where the drone is located to assess the potential impact of the external environment on motor operation.

3. The motor fault-tolerant control method for a high-altitude working UAV according to claim 1 is characterized in that: Determining the fault type of the target motor according to the operating status data includes: Based on the collected operating status data, the vibration signal is analyzed. When the vibration amplitude exceeds the preset normal operating range and there are irregular periodic changes, it is determined to be a rotor imbalance fault; Based on the comparison between the collected current signal and the rated current range of the target motor, when the current value continues to exceed the set safety threshold and the motor power output fails to drop significantly, it is determined to be a current overload fault.

4. The motor fault-tolerant control method for a high-altitude working UAV according to claim 3 is characterized in that: The step of determining the fault type of the target motor according to the operating status data further includes: The collected temperature signals are monitored in real time. When the temperature value of the target motor continues to rise and exceeds the set temperature upper limit, and the influence of the ambient temperature on it is eliminated, it is determined to be a thermal runaway fault; Comprehensively analyze the speed signal and vibration signal. When the speed is unstable and accompanied by low-frequency vibration characteristics, and the current signal does not exceed the normal range, it is determined to be a bearing fault. Combining the current signal and the speed signal, when the current signal shows obvious fluctuations and one phase current tends to zero, and the motor speed drops significantly, it is determined to be a phase loss fault.

5. The motor fault-tolerant control method for a high-altitude working UAV according to claim 1 is characterized in that: When a current overload is detected and the flight altitude of the drone exceeds a set value, the power output of the target motor is reduced, and the thrust of other motors is redistributed to maintain flight stability, including: The current value of the target motor is monitored in real time by a current sensor. When it is detected that the current value of the target motor continuously exceeds the set safety threshold, it is judged as a current overload condition; According to the reading of the drone's flight altitude sensor, confirm whether the drone's current flight altitude exceeds the set safety altitude value. If the flight altitude meets the over-altitude condition, enter the power reduction adjustment process; During the power reduction adjustment process, the power output of the target motor is gradually reduced by reducing the PWM duty cycle of the target motor, and its power is limited to a safe range to avoid overheating or damage to the motor; The flight control system calculates the available thrust of other motors in real time, and evenly distributes the thrust gap caused by the reduction of the target motor power to the remaining motors, especially the adjacent motors, to ensure the overall thrust balance of the drone. Combined with the drone's attitude sensor data, the thrust output of the remaining motors is dynamically adjusted to control the drone's pitch and roll angles to keep the drone in a stable flight state.

6. The motor fault-tolerant control method for a high-altitude working UAV according to claim 1 is characterized in that: When thermal runaway is detected and the tilt angle of the drone is greater than a preset threshold, the target motor is switched to an intermittent operation mode, and the internal heat accumulation of the target motor is reduced by setting a fixed stop and start time ratio, including: The temperature of the target motor is monitored in real time by a temperature sensor. When the temperature signal shows that the temperature of the target motor continues to rise and exceeds the set safety threshold, it is confirmed that the target motor is in thermal runaway; Combined with the attitude sensor data of the drone, the pitch and roll angles of the drone are detected. When the tilt angle is greater than the preset threshold, the protection mechanism of the target motor is triggered; Enter intermittent operation mode and set the ratio of running and stopping time of the target motor to ensure that there is enough stopping time after each operation cycle to reduce the heat accumulation inside the motor; When the target motor is in intermittent operation mode, the flight control system redistributes the thrust of the remaining motors in real time to compensate for the thrust loss during the intermittent shutdown of the target motor, and adjusts the output power of other motors to keep the attitude of the drone stable; Monitor the operating status of other motors to ensure that the redistributed thrust does not cause other motors to overload or overheat, thus ensuring the safe operation of the entire UAV power system; The intermittent operation mode continues until the temperature of the target motor returns to a safe range or the drone completes the current mission and lands safely. During this process, the drone maintains a stable flight attitude and controllable flight capability.

7. The motor fault-tolerant control method for a high-altitude working UAV according to claim 1, characterized in that: When a bearing fault is detected and the UAV is in a long-term hovering state, the rotation speed of the target motor is reduced and the thrust output of other motors is adjusted to reduce the axial load of the target motor, including: The operating status of the target motor is monitored in real time through the vibration sensor and the speed sensor. When the vibration signal shows abnormal axial vibration and irregular fluctuations in speed, it is determined that the bearing of the target motor is faulty. Combined with the UAV flight control data, it is confirmed that the UAV is currently in a long-term hovering state, that is, the flight controller's altitude data and attitude data show that the UAV remains motionless at a fixed position for a time exceeding a preset threshold; Enter the adjustment process, gradually reduce the speed of the target motor and control it within the lower limit of the rated speed to reduce the mechanical stress of the bearing, while maintaining sufficient thrust output to avoid the UAV's attitude instability; The flight control system redistributes the thrust of the remaining non-faulty motors, giving priority to increasing the thrust of the motors at the diagonal position of the target motor to share the axial load of the target motor. Combined with the real-time data of the attitude sensor, the output thrust of each motor is dynamically adjusted to ensure that the pitch and roll angles of the drone remain within a stable range, thereby maintaining the overall balance of the drone while reducing the target motor load.

8. The motor fault-tolerant control method for a high-altitude working UAV according to claim 1 is characterized in that: When a rotor imbalance is detected and the UAV is flying at a high wind speed, the lateral component of the target speed is calculated, and the PWM duty cycle of the motor is adjusted to offset the offset torque caused by the imbalance, including: According to the following formula 1, the lateral component of the target motor speed is calculated: ； in, represents the lateral component of the target motor; Indicates The mass of each vibrating mass point; Indicates The angular velocity corresponding to the vibration frequency of each vibrating mass point; For the The vibration phase angle of each vibrating mass point; is the roll angle of the drone; Indicates the total number of mass points involved in vibration analysis; According to the following formula 2, the additional offset torque caused by rotor imbalance is calculated: : ； in, represents the additional offset moment; is the ambient wind speed; is the reference wind speed; Indicates The distance from the vibrating mass point to the rotation axis; The lateral correction moment is calculated according to the following formula 3: ； in, represents the correction torque; is the yaw angle of the drone; The PWM duty cycle of the target motor is calculated by the following formula 4: : ； in, is the equivalent resistance of the target motor; is the motor torque constant; is the battery voltage of the target motor.

9. The motor fault-tolerant control method for a high-altitude working UAV according to claim 1, characterized in that: When a phase failure is detected and the thrust of the drone is insufficient, the load of the target motor is reduced, the emergency power reduction mode is switched, and the attitude of the drone is adjusted to balance the overall thrust distribution, including: According to the following formula 5, calculate the power factor of the target motor : ； in, Indicates the remaining working phases of the current target motor; Indicates the number of complete working phases of the target motor; Indicates the additional offset torque caused by phase failure; Indicates the maximum allowable torque of the target motor; According to the following formula 6, calculate the PWM duty cycle of the target motor: ； in, Indicates the original PWM duty cycle of the target motor; Indicates the adjusted PWM duty cycle; According to the following formula 7, calculate the drone attitude correction factor : ； in, represents the total thrust requirement of the UAV; is the current roll angle of the drone; is the current pitch angle of the drone; Indicates the remaining working phases of the current target motor; Indicates the number of complete working phases of the target motor; The adjusted thrust of the target motor is calculated according to the following formula 8: ； in, is the adjusted target motor thrust; is the original target motor thrust; is the power factor of the target motor; The remaining motor thrust is calculated according to Formula 9 below: ； in, After redistribution Thrust of a non-faulty motor; Before adjustment Thrust of a non-faulty motor; is the attitude correction factor; is the number of non-faulty motors currently available.

10. The motor fault-tolerant control method for a high-altitude working UAV according to claim 1, characterized in that: After the adjustment operation is completed, the task execution mode of the UAV is adjusted according to the operating state of the target motor, including reducing the high-altitude operation task load or starting the landing mode, until the UAV task is completed or landed safely, including: The remaining performance of the target motor is evaluated in real time through its operating status data, including the current power output capacity, speed stability, and temperature change trend, to determine whether the target motor can continue to support the current high-altitude operation task; When the evaluation results show that the remaining performance of the target motor is insufficient to complete the current task, the load of the aerial work task is immediately reduced; Combined with the flight control data of the UAV, it determines whether the current environmental conditions are suitable for continuous flight. If the environmental conditions are unfavorable or the operating status of the target motor deteriorates further, the landing mode is initiated; When the landing mode is activated, the drone's landing path is planned to the nearest safe area first, and the drone's stable descent posture is maintained by adjusting the thrust distribution of other motors, and the flight altitude is gradually reduced; During the landing process, the status of the target motor and other motors is monitored in real time, and the thrust output and attitude of the drone are dynamically adjusted to ensure the safety and controllability of the landing process.

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