Rotor device, aircraft and control method

Abstract

The embodiment of the application provides a rotor device, an aircraft and a control method, relates to the technical field of aviation electric propulsion and rotor control. The rotor device comprises a blade, a pitch actuator, a propulsion motor, a first inverter, a second inverter and a controller. The controller is configured to start a mode switching preset process to reserve a control margin for mode switching when a preset trigger condition is met, and perform switching from a current drive channel to a target drive channel when a switching trigger condition is met. The switching process comprises: making the electromagnetic torques output by the two drive channels change cooperatively and maintaining the total torque continuously through torque gradual change control, and adjusting the pitch angle of the blade according to the torque change control pitch actuator to make the blade speed change less than a preset change threshold. Therefore, torque spikes can be avoided, the speed is basically stable, and the problem of speed drop or thrust mutation is avoided.

Description

Technical Field

[0001] This application relates to the field of aviation electric propulsion and rotor control technology, and in particular to a rotor device, an aircraft, and a control method. Background Technology

[0002] Heavy-duty multi-rotor cargo aircraft can perform transportation, slinging, and loading / unloading tasks in mountainous, plateau, and complex wind environments, significantly reducing labor costs. Among these, aircraft employing dual-redundant electric drives can provide greater thrust and higher reliability. The propulsion motors of dual-redundant electric drive aircraft can be configured with multiple operating modes to cope with various problems encountered during flight missions. However, in related technologies, mode switching can lead to issues such as speed dips or sudden thrust changes, resulting in attitude coupling and safety risks for the aircraft. Summary of the Invention

[0003] To overcome the safety issues in the mode switching process in related technologies, embodiments of this application provide a rotor device, an aircraft, and a control method.

[0004] In one aspect, this application provides a rotor device, including blades, a pitch actuator, a propulsion motor, a first inverter, a second inverter, and a controller.

[0005] A pitch actuator is used to adjust the pitch angle of the propeller blades, and a propulsion motor is used to drive the propeller blades, including a first winding and a second winding. A first inverter and a second inverter are used to adjust the electromagnetic torque of the first winding and the second winding, respectively. The first inverter and the first winding form a first drive channel, and the second inverter and the second winding form a second drive channel. A controller is connected to the pitch actuator, the first inverter, and the second inverter.

[0006] The controller is used to initiate a mode switching preset process when preset trigger conditions are met, thus reserving control margin for mode switching; and to execute a switch from the current drive channel to the target drive channel when the switching trigger conditions are met. This switching process includes: using torque gradient control to coordinate the change in electromagnetic torque output from the two drive channels and maintain continuous total torque; and controlling the pitch actuator to adjust the blade pitch angle according to the torque change, so that the change in blade speed is less than a preset threshold.

[0007] In some embodiments, the controller is further configured to control the two drive channels to synchronize electrical angle and current during the mode switching preset process or during the switching process, so as to enter a synchronous hot standby state.

[0008] In some embodiments, the controller is further configured to acquire at least one of the following parameters after the switching process has completed: The current of the drive channel, the internal temperature rise, the error between the actual speed of the propulsion motor and the target speed value, and the error between the actual thrust of the rotor device and the target thrust value; Furthermore, if the parameters do not meet the corresponding preset security threshold, a downgraded security operation process is initiated.

[0009] In some embodiments, the controller is further configured to, during the initiation of a degraded security operation process: Based on the preset drive channel constraints, determine the current available electromagnetic torque value of the rotor device; The controllable thrust range is determined based on the preset pitch angle and speed constraints, disturbance correction constraints, and the available electromagnetic torque value. Adjust the target blade rotation speed so that the actual thrust of the rotor assembly is within the controllable thrust range; or... If the maximum value of the controllable thrust range is less than the preset safe thrust value, the emergency response procedure will be initiated.

[0010] In some embodiments, the controller is further configured to: Based on changes in environmental wind conditions, predict the load torque disturbance value and thrust disturbance value; Based on the load torque disturbance value and the thrust disturbance value, determine the pitch angle compensation value and the torque compensation value; The pitch angle and the electromagnetic torque are adjusted based on the pitch angle compensation value and the torque compensation value.

[0011] In some embodiments, the controller is further configured to: Monitor the current task phase and the health metrics of each drive channel; If the health index of at least one drive channel is detected to be declining, and / or if the current task stage is detected to be a preset high-risk task stage, the preset trigger condition is determined to be met. The high-risk mission phases include at least one of the following: take-off and landing phase, hoisting phase, sudden loading phase, sudden unloading phase, and working phase in strong gust wind zone.

[0012] In some embodiments, the controller is also configured to monitor the upper limit of the output power of each drive channel and device fault codes; If the health index is detected to be less than the preset health threshold, and / or if the upper limit of the output power is detected to be less than the target power value, and / or if the device fault code is detected, it is determined that the switching trigger condition is met.

[0013] In some embodiments, the controller is further configured to obtain at least one of the following parameters: Ambient temperature, ambient wind speed, load gravity, load torque, device fault codes, flight speed, actual rotation speed, electrical angle, current, voltage, winding open circuit characteristics, winding short circuit characteristics, and device internal temperature; The health index is determined based on the parameters.

[0014] Secondly, embodiments of this application also provide a control method for a rotor device.

[0015] The rotor assembly includes blades, a pitch control mechanism, a propulsion motor, a first inverter, and a second inverter. The pitch control mechanism is used to adjust the pitch angle of the blades, and the propulsion motor, which drives the blades, includes a first winding and a second winding. The first inverter and the second inverter are respectively used to adjust the electromagnetic torque of the first winding and the second winding. The first inverter and the first winding form a first drive channel, and the second inverter and the second winding form a second drive channel.

[0016] The control method includes the following steps S1 to S2: Step S1: If the preset trigger conditions are met, start the mode switching preset process to reserve control margin for mode switching.

[0017] Step S2: If the switching trigger condition is met, perform a switch from the current drive channel to the target drive channel. This switching process includes: using torque gradient control to coordinate the electromagnetic torque outputs of the two drive channels and maintain continuous total torque; and controlling the pitch actuator to adjust the blade pitch angle based on the torque change, so that the change in blade speed is less than a preset threshold.

[0018] Thirdly, embodiments of this application also provide an aircraft, including a plurality of rotor devices as described in any of the above embodiments and a cooperative distributor. The cooperative distributor is used to send a thrust command signal to each rotor device, so that the controller adjusts the pitch angle and electromagnetic torque of the corresponding rotor device according to the thrust command signal.

[0019] Fourthly, embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the control method described in the above embodiments.

[0020] Fifthly, embodiments of this application also provide a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the control method as described in the above embodiments.

[0021] The technical solutions provided by the embodiments of this application may include the following beneficial effects: In this embodiment, when preset triggering conditions are met, such as in the event of a potential operational anomaly, a preset mode switching process is initiated in advance to reserve control margin for mode switching. Subsequently, when switching triggering conditions are met, such as if an operational anomaly event is confirmed, a switch from the current drive channel to the target drive channel is executed. This switching process includes: using torque gradient control to coordinate the electromagnetic torque outputs of the two drive channels and maintain continuous total torque; and controlling the pitch actuator to adjust the blade pitch angle based on the torque change, so that the change in blade speed is less than a preset threshold.

[0022] In other words, during the switching process, the pitch angle and electromagnetic torque are adjusted in a coordinated manner. While adjusting the pitch angle, the electromagnetic torque is controlled to change smoothly and gradually to avoid torque spikes, ensure that the speed is basically stable, and avoid problems such as speed drop or sudden thrust changes.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this application, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0025] Figure 1 This is an application scenario diagram of an aircraft provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a rotor device provided in an embodiment of this application; Figure 3 This is a schematic diagram of a mode switching strategy provided in an embodiment of this application; Figure 4 This is a flowchart of a rotor device control method provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an aircraft provided in an embodiment of this application. Detailed Implementation

[0026] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0027] Figure 1 This is an application scenario diagram of an aircraft provided in an embodiment of this application. A heavy-load multi-rotor cargo aircraft refers to an aircraft that includes multiple rotor devices and is capable of carrying heavy cargo to perform flight missions.

[0028] To improve aircraft reliability, propulsion motors are gradually evolving from single-channel drive motors to dual-redundant drive motors (i.e., dual-channel propulsion motors). However, current research on dual-redundant drive motors largely focuses on fault tolerance and current sharing at the motor and power levels to improve their performance. In actual aircraft applications, using dual-redundant drive motors as propulsion motors presents even more complex challenges. These include flight environments with strong and rapidly changing aerodynamic load disturbances, the need to balance high thrust and stable speed, and the risk of failure due to high power density, vibration, and thermal stress. All of these factors place higher demands on propulsion systems.

[0029] Furthermore, in aircraft, the propulsion system also needs to consider the influence of the blade pitch angle. Currently, there are two main technical approaches to aircraft control: speed control and pitch control. Speed ​​control, also known as constant-pitch control, means that the blade pitch angle remains constant, and the aircraft's attitude is mainly controlled by adjusting the blade speed. Pitch control, also known as variable-pitch control or constant-speed control, mainly controls the aircraft's attitude by adjusting the pitch angle. In the constant-speed control approach, motor power consumption can be significantly reduced through coordinated optimization of speed and pitch.

[0030] Figure 2 This is a schematic diagram of the structure of a rotor device provided in an embodiment of this application.

[0031] The rotor device includes blades 10, a pitch actuator 20, a propulsion motor 30, a first inverter 41 and a second inverter 42, and a controller 60.

[0032] The variable pitch actuator 20 is used to adjust the pitch angle of the propeller blade 10, and the propulsion motor 30 is used to drive the propeller blade 10, including a first winding 31 and a second winding 32. A first inverter 41 and a second inverter 42 are used to adjust the electromagnetic torque of the first winding 31 and the second winding 32, respectively. The first inverter 41 and the first winding 31 form a first drive channel 51, and the second inverter 42 and the second winding 32 form a second drive channel 52. A controller 60 is connected to the variable pitch actuator 20, the first inverter 41, and the second inverter 42.

[0033] For example, during the operation of the rotor device, based on the constant speed control system, the controller 60 can determine the corresponding pitch angle and the electromagnetic torque corresponding to each drive channel according to the target rotational speed.

[0034] The controller 60 sends a first control signal to the first inverter 41 to control the first winding 31 to output a first electromagnetic torque. It also sends a second control signal to the second inverter 42 to control the second winding 32 to output a second electromagnetic torque. The sum of the first and second electromagnetic torques is the electromagnetic torque output by the propulsion motor 30. Under this electrical torque, the blade 10 can reach the target speed. Additionally, the controller 60 sends a third control signal to the pitch actuator 20 to control the pitch actuator 20 to adjust the blade 10's pitch angle to the target value.

[0035] It is understandable that the load torque during the rotation of the blade 10 is related to both its pitch angle and rotational speed. With a constant rotational speed, a change in the pitch angle will cause a change in the load torque. If the electromagnetic torque remains constant, this will in turn cause fluctuations in the rotational speed. That is, the constant speed control system is a negative feedback regulation process. The pitch angle and electromagnetic torque determined by the controller 60 based on the target rotational speed value in this embodiment refer to the calculation results corresponding to the balanced state of the negative feedback system.

[0036] During the process of propulsion motor 30 controlling blade 10 to reach the target speed, the electric drive inner loop adopts current closed-loop and torque control. By real-time detection of the phase current of the drive channel and comparison with the target current value, the controller 60 can calculate and adjust according to the error using methods such as field-oriented control or equivalent vector control, so that the actual current can quickly and accurately track the target value.

[0037] To ensure operational safety and extend the lifespan of the device, rotor systems typically need to meet certain technical requirements during operation, including current limiting, voltage limiting, and temperature limiting constraints on the drive channels. This means that the current and voltage of the channels, such as the input voltage, input current, output voltage, and output current of the inverter, as well as internal temperature or temperature rise, must all meet the corresponding technical requirements. These technical requirements can be determined based on the type of flight mission, environmental conditions, or the material properties of the device itself.

[0038] Based on the winding-related constraints, during the process of adjusting the electromagnetic torque, the controller 60 also needs to ensure that each winding has anti-saturation capability and can maintain its state.

[0039] For the dual-channel propulsion motor 30 in the rotor device, multiple operating modes can be preset according to the working status of its two drive channels.

[0040] For example, mode M1 is the main channel mode. In this mode, the first drive channel 51 bears the main torque, that is, the electromagnetic torque is mainly output by the first winding 31 to drive the blade 10 to rotate, and the second drive channel 52 is in standby mode.

[0041] Mode M2 ​​is a parallel sharing mode. In this mode, the two drive channels work together and the output is distributed according to the preset weight to reduce the current and temperature rise of each drive channel and improve peak capacity.

[0042] Mode M3 is a backup channel takeover mode, for example, in the event of a failure or abnormality of the first drive channel 51, the second drive channel 52 takes over the flight mission.

[0043] Furthermore, when the output capacity of the drive channel is limited, mode M4, also known as degraded safety mode, can be set. In this mode, the controller 60 can adjust the pitch angle to unload the load, or reduce the output electromagnetic torque to reduce the pressure on the corresponding drive circuit, ultimately ensuring equipment safety. In addition, the controller can also issue an alarm signal in this mode.

[0044] When faced with changes in the external environment, load, or its own performance, the aircraft can adaptively switch operating modes to ensure the execution of flight missions or to maintain its own flight attitude and safety.

[0045] Figure 3 This is a schematic diagram of a mode switching strategy provided in an embodiment of this application.

[0046] Taking the current operating mode M1 as an example, if the first drive channel 51 malfunctions or is abnormal (e.g., excessive temperature rise), it can be switched to mode M3. Afterwards, if the first drive channel 51 returns to normal, it can be switched to mode M2.

[0047] Alternatively, if the current operating mode is M1, it can be switched to mode M2 ​​in the event of a sudden load (a step increase in thrust demand) or a large gust of wind disturbance, or if the maximum thrust of the first drive channel 51 does not meet the demand.

[0048] When the output capability of the drive channel is limited, mode M4 can be switched.

[0049] It is understood that this is merely one possible example and is not intended to limit the mode switching strategy. The term "operation mode switching" as used in this application includes switching from any one mode to another.

[0050] To avoid potential issues such as a drop in speed or a sudden change in thrust during mode switching, in this embodiment, the controller 60 is configured to: initiate a mode switching preset process when preset trigger conditions are met, to reserve control margin for mode switching; and execute a switch from the current drive channel to the target drive channel when switching trigger conditions are met. During the switching process, torque gradient control ensures that the electromagnetic torque output by the two drive channels changes synchronously and maintains continuous total torque. Furthermore, the pitch actuator 20 is controlled to adjust the blade pitch angle based on the torque change, so that the change in blade speed 10 is less than a preset threshold.

[0051] The current driving channel mentioned here can be one or two driving channels. The target driving channel can also be one or two driving channels. The specific choice depends on the operating mode before and after the switch.

[0052] The preset trigger condition is met, meaning there is a possibility of operational abnormality. The switching trigger condition is met, meaning if an operational abnormality event is confirmed to have occurred.

[0053] For example, the controller 60 can predict the risks of executing a corresponding flight mission based on the mission type and experience, or based on the performance of the rotor device itself. If the risk is high, it indicates a possibility of operational abnormality. Based on this, in this embodiment, the controller 60 controls the initiation of a preset mode switching process to reserve control margin for mode switching. Subsequently, if an operational abnormality event is confirmed and a mode switch is required, the controller can control the rotor device to respond quickly, avoiding a prolonged mode switching process and preventing problems such as speed drop or thrust abrupt changes.

[0054] For example, under certain operating conditions, the rotor device normally performs flight missions in mode M1. During the process, the first drive channel 51 of the rotor device may be damaged (e.g., the temperature rise is relatively severe) and it may be difficult to maintain the current flight mission. It is necessary to switch to mode M3 to continue to complete the flight mission.

[0055] According to an embodiment of this application, the controller 60 continuously monitors the performance of the first drive channel 51 and initiates a switching preset process when preset trigger conditions are met. For example, the second electromagnetic torque output by the second drive channel 52 is increased from zero to a smaller value, so that the second drive channel 52 is upgraded from zero torque hot standby to small torque hot standby, which helps to reduce takeover delay and improve mode switching speed. Alternatively, the rotor speed of the blade 10 is slightly increased and the pitch angle is slightly decreased, so that the slope of the curve in the relationship between thrust and pitch angle increases, which means that the pitch angle's ability to adjust thrust increases, thus reserving space for rapid loading of the pitch angle during mode switching.

[0056] Subsequently, the controller 60 continuously monitors the performance of the first drive channel 51. When the switching trigger condition is met, it performs a switch from the current drive channel to the target drive channel, that is, the output of the first drive channel 51 is switched to the output of the second drive channel 52.

[0057] During the switching process, torque gradual control ensures that the electromagnetic torques output by the two drive channels change in tandem, maintaining a continuous total torque. Here, "torque gradual" and "torque continuity" refer to the torque-time relationship curve being continuously differentiable. That is, there will be no sudden torque changes. The coordinated change of the electromagnetic torques output by the two drive channels means that both the first and second electromagnetic torques change continuously and gradually, without torque gaps or spikes. For example, the first electromagnetic torque is controlled to gradually decrease while the second electromagnetic torque gradually increases, ensuring a continuous and smooth change in the total torque.

[0058] Simultaneously, the pitch angle is adjusted synchronously according to the change in total torque to maintain a constant rotational speed. Here, "constant rotational speed" means that the speed fluctuation is within a preset range, that is, the change in the rotational speed of blade 10 is less than a preset threshold.

[0059] In summary, in this embodiment, before an operational anomaly occurs, the controller 60 can predict and initiate a preset mode switching process, thereby enabling a rapid response upon confirmation of an operational anomaly and ensuring control capability during the response phase. During the mode switching process after confirming an operational anomaly, the electromagnetic torque and pitch angle of the two drive channels are coordinated to ensure continuous electromagnetic torque variation, avoiding torque gaps and spikes, and preventing issues such as speed drops or sudden thrust changes. This allows for seamless switching of operating modes, improving safety and reliability.

[0060] In some embodiments, during the switching process, the controller 60 also implements a seamless transition of the control state. Taking the switch from mode M1 to mode M3 as an example, in conjunction with the constant-speed negative feedback adjustment process described above, before the mode switch, the controller 60 generates some state parameters corresponding to the first drive channel 51 during the negative feedback adjustment calculation process, such as the integral state, limiting state, and anti-saturation state of constant-speed regulation. During the switching process, the controller 60 also migrates the above parameters to the second drive channel 52 according to rules. It can be understood that if switching from mode M1 to mode M2, the controller 60 migrates the above parameters to the two parallel drive channels according to rules to avoid secondary disturbances caused by state jumps after the switch.

[0061] In some embodiments, the controller 60 is further configured to control the two drive channels to synchronize electrical angle and current during the mode switching preset process or during the switching process, so as to enter a synchronous hot standby state.

[0062] That is, before performing the operation of adjusting the electromagnetic torque and pitch angle, the two drive channels are pre-controlled to synchronize, ensuring that each drive channel is in a state where it can output torque instantaneously.

[0063] In the rotor assembly, the input power of the two drive channels can be connected to different power supply circuits of the same bus, or they can be connected to different buses to further improve system reliability. If one of the drive channels is in standby mode before mode switching, the controller 60 will pre-charge the standby drive channel on the bus and establish synchronization current before performing the operation of adjusting the electromagnetic torque and pitch angle to ensure that it enters the synchronous hot standby state.

[0064] For example, under certain operating conditions, the rotor device needs to switch from mode M1 to mode M2. The controller 60 can, upon confirming that the preset trigger conditions are met, immediately pre-charge the power supply bus of the second drive channel 52, establish a synchronization current, and control the electrical angles of the two drive channels to synchronize. This facilitates a rapid response when an abnormal operating event is detected.

[0065] Alternatively, in the event of an abnormal operation, the synchronous hot standby operation of the second drive channel 52 can be quickly achieved based on the preparation work of the mode switching preset process.

[0066] In some embodiments, the controller 60 is further configured to acquire at least one of the following parameters after the switching process is completed: the current of the drive channel, the internal temperature rise, the error between the actual rotational speed and the target rotational speed of the propulsion motor 30, and the error between the actual thrust and the target thrust of the rotor device.

[0067] Furthermore, if the parameters do not meet the corresponding preset security threshold, a downgraded security operation process is initiated.

[0068] That is, after the mode switch is completed, the controller 60 also needs to evaluate the current operating state of the rotor device. If the drive channel current exceeds the safe current threshold, it indicates that the rotor device is in an overcurrent operating state. Since long-term overcurrent operation will affect the device performance and lifespan, and in severe cases will quickly lead to damage and malfunction of the rotor device, the strategy does not allow the rotor device to maintain the operating state after the mode switch. Based on this, in this embodiment of the application, the controller 60 will control the initiation of the degraded safe operation process and control the rotor device to enter mode M4 to ensure device safety.

[0069] The same applies to other parameters. If the temperature rise exceeds the safe temperature rise threshold, the rotational speed error exceeds the safe rotational speed error threshold, or the thrust error exceeds the safe thrust error threshold, it indicates that the current operating state cannot meet the corresponding technical requirements. By initiating the degraded safety operation procedure, the performance of the flight mission and the safety of the equipment can be balanced within the capabilities of the rotor system.

[0070] In some embodiments, the controller 60 is further configured to, during the initiation of a degraded security operation process: Based on the preset drive channel constraints, determine the current available electromagnetic torque value of the rotor device; The controllable thrust range is determined based on the preset pitch angle and speed constraints, disturbance correction constraints, and the available electromagnetic torque value. Adjust the target rotational speed of blade 10 so that the actual thrust of the rotor assembly is within the controllable thrust range; or... If the maximum value of the controllable thrust range is less than the preset safe thrust value, the emergency response procedure will be initiated.

[0071] Based on the preceding explanations regarding technical requirements, the constraints on the drive channel here include current limiting, voltage limiting, and temperature limiting. For example, based on the constraints of the inverter's input current, output current, input voltage, and output voltage, combined with the temperature rise constraints during operation and factors such as the inherent losses of the drive motor 30, the controller 60 can determine the maximum output power of the drive channel. In other words, it can determine the usable value of the electromagnetic torque of the drive channel.

[0072] In constant-speed negative feedback control systems, the deviation error between the actual speed and the target speed is typically constrained to not exceed a preset safe speed error threshold. Furthermore, the adjustable range of the pitch angle, the rate of change of the pitch angle during adjustment, and other parameters related to the pitch angle usually also have corresponding constraints.

[0073] In the process of controlling the pitch actuator 20 to adjust the pitch angle and controlling the inverter to adjust the electromagnetic torque, the controller 60 needs to meet the internal constraints of the rotor device mentioned above.

[0074] On the other hand, since the external environment of the rotor device may change at any time, the above control process also needs to consider the impact of environmental disturbances in order to reserve disturbance adjustment capability.

[0075] In this embodiment, the disturbance correction constraint can be predicted based on the current environment. For example, based on the current operating conditions, the disturbance correction constraint corresponding to a certain time window in the future can be predicted. Alternatively, it can be determined based on the disturbance parameters corresponding to the situation with the greatest disturbance impact in historical records, such as determining the disturbance correction constraint based on the wind speed of the maximum gust in historical records. Or, it can be preset based on empirical values, such as preset based on the historical maximum wind speed or average wind speed of the task area.

[0076] By taking into account both internal and external constraints, the controller 60 can ultimately determine the controllable thrust range of the rotor device, that is, the maximum and minimum thrust that the rotor device can output.

[0077] If the current thrust requirement does not match the controllable thrust range, the target speed can be updated, and the corresponding pitch angle and electromagnetic torque can be redefined to avoid damage to the rotor system caused by forced output.

[0078] For example, in a quadcopter, if the maximum controllable thrust range of one of the rotor units is less than the current thrust requirement, that rotor unit and the rotor units diagonally opposite it can synchronously reduce their thrust output, thereby maintaining relative stability of the aircraft's attitude. For instance, the controllers 60 of these two rotor units can reduce the target rotational speed and adjust the pitch angle and electromagnetic torque to within constraints based on the reduced target rotational speed. Based on this, although the thrust provided by the rotor units may be less than the required value before adjustment, the safety of the system can be guaranteed. Alternatively, if the thrust output of the two diagonally opposite rotor units decreases while the thrust output of the two diagonally opposite rotor units increases, although the output of the four rotor units is unbalanced, the overall attitude remains relatively stable, ensuring overall safety.

[0079] In some high-risk flight phases, such as low-altitude flight or sling-loaded flight, corresponding thrust safety values ​​are pre-set. If the maximum value within the controllable thrust range is less than this thrust safety value, emergency procedures are initiated, such as hovering or forced landing.

[0080] In some embodiments, the controller 60 is further configured to: Based on changes in environmental wind conditions, predict the load torque disturbance value and thrust disturbance value; Based on the load torque disturbance value and the thrust disturbance value, determine the pitch angle compensation value and the torque compensation value; The pitch angle and the electromagnetic torque are adjusted based on the pitch angle compensation value and the torque compensation value.

[0081] As mentioned above, the effects of environmental disturbances need to be considered during the constant-speed control negative feedback adjustment process. If the environmental disturbances are corrected through iterative adjustments during the adjustment process, the constant-speed negative feedback adjustment process will take a long time. Adding a mode switching process further increases the computational load on the controller 60, which is detrimental to quickly achieving stable control of the rotor device.

[0082] In view of this, in the embodiments of this application, the controller 60 can predict and correct aerodynamic disturbances based on the ambient wind conditions.

[0083] For example, the controller 60 can acquire environmental sensing parameters, such as current ambient air pressure, wind speed, and the height of the device. Combined with preset test correction parameters, it uses pitch-airspeed-efficiency mapping and real-time interpolation calculation to predict the load torque disturbance value and thrust disturbance value in the future preset time window.

[0084] Alternatively, the controller 60 can be pre-programmed with algorithms or models such as online learning, segmented planning, and fault adaptation, for example, Q-learning algorithms or neural network models. Based on current environmental wind conditions, it can predict the load torque disturbance and thrust disturbance values ​​corresponding to a preset time window in the future.

[0085] Based on the prediction results, the controller 60 can determine in advance the pitch angle compensation value and torque compensation value required to correct the disturbance.

[0086] Subsequently, during the constant speed negative feedback adjustment process, based on the pitch angle compensation value and torque compensation value, the controller 60 can quickly determine the first control signal, the second control signal and the third control signal to rapidly adjust the first electromagnetic torque, the second electromagnetic torque and the pitch angle to a steady state.

[0087] For example, the embodiments of this application illustrate the situation where the rotor device needs to switch modes due to a sudden strong gust of wind.

[0088] As described above, based on the acquired environmental perception parameters, the controller 60 can predict the existence of significant disturbances within a preset time window, indicating that maintaining the current operating state may pose a considerable risk. Therefore, it initiates a preset procedure for switching control modes, reserving control margin for subsequent mode switching. Furthermore, the controller 60 also pre-calculates and determines the pitch angle compensation value and torque compensation value based on the predicted load torque disturbance value and thrust disturbance value.

[0089] During the mode switching process, the controller 60 controls the two drive channels to change in coordination with the torque compensation value mentioned above, and determines the pitch angle after switching by combining the pitch angle compensation value.

[0090] In determining the pitch angle compensation value, it can be based on the load torque disturbance value and the available electromagnetic torque margin of the rotor assembly. It is understood that the electromagnetic torque that each drive channel can output is finite. At any given moment during operation, the available electromagnetic torque margin is negatively correlated with the currently output electromagnetic torque. The controller 60 can perform a short-term unloading operation, i.e., a short-term reduction in thrust, based on the relationship between the available electromagnetic torque margin, the load torque disturbance value, and the current load torque. Once the available electromagnetic torque margin recovers, steady-state control is resumed according to the load requirements.

[0091] For example, if the switching moment causes a decrease in the available margin of the current electromagnetic torque, such as if the rotor needs to switch from mode M1 to mode M3, but the maximum electromagnetic torque that the second drive channel 52 can output is less than the maximum electromagnetic torque that the first drive channel 51 can output, in order to avoid insufficient electromagnetic torque output and resulting in a drop in speed, the pitch angle can be adjusted briefly to reduce the load torque, thereby maintaining a stable speed.

[0092] Alternatively, if the rotor system switches from mode M3 to mode M2, the two drive channels are connected in parallel to share the output. For each drive channel, the electromagnetic torque can be recovered with margin. Then, according to the load requirements, that is, according to the thrust target value, the corresponding pitch angle can be readjusted and steady-state control can be restored.

[0093] For example, this aerodynamic disturbance prediction and correction function can also be used in the calculation process of constraining the controllable thrust range during degraded safe operation procedures. For instance, the disturbance correction constraints can be adjusted based on the predicted thrust disturbance values.

[0094] In some embodiments, the controller 60 is further configured to: Monitor the current task phase and the health metrics of each drive channel; If the health index of at least one drive channel is detected to be declining, and / or if the current task stage is detected to be a preset high-risk task stage, the preset trigger condition is determined to be met. The high-risk mission phases include at least one of the following: take-off and landing phase, hoisting phase, sudden loading phase, sudden unloading phase, and working phase in strong gust wind zone.

[0095] For example, based on historical experience or experimental data, high-risk mission phases can be predefined within the controller 60. During the execution of a flight mission, the controller 60 monitors the current mission phase in real time. When entering the takeoff and landing phase, slinging phase, sudden loading phase, sudden unloading phase, or working phase in a strong gust of wind, it can be considered that there is a possibility of operational anomalies, and thus the preset mode switching procedure is initiated.

[0096] Alternatively, the rotor assembly can be equipped with a sensing system to collect external environmental parameters and its own operating status parameters. For example, a pitch angle sensor can be used to collect parameters such as the pitch angle and pitch angle change rate of the blade 10, while a speed sensor (or encoder) can be used to collect winding electrical angle parameters and speed parameters. A temperature sensor can be used to collect the external ambient temperature or the internal temperature of the assembly. A load sensor can be used to collect the load gravity. A vibration sensor can be used to collect mechanical vibration parameters at the corresponding location. Furthermore, the controller 60 can also be configured with a sampling circuit to collect internal control parameters such as the bus voltage and phase current of the drive channel.

[0097] That is, regardless of whether the parameters are generated by the sensing system, preset and stored in the controller 60, or output by the relevant actuators during operation, in this embodiment of the application, the controller 60 can obtain at least one of the following parameters: ambient temperature, ambient wind speed, load gravity, load torque, device fault code, flight speed, actual rotation speed, electrical angle, current, voltage, winding open circuit characteristic quantity, winding short circuit characteristic quantity, and device internal temperature.

[0098] Based on the parameters, the controller 60 can determine the health index of each drive channel. That is, the controller 60 has fault diagnosis and health assessment functions; it can determine whether there is a fault in the rotor device based on parameter changes, and if a fault is found, it can pinpoint the fault location and issue an alarm. If no fault is found, it can also monitor the health status, serving as a warning.

[0099] The health status of drive channels can be reflected through a comprehensive score, which can incorporate multiple evaluation factors. For example, the operating status of the drive channel can be evaluated based on internal temperature changes and parameters such as current and voltage. Alternatively, the working capacity of the drive channel can be evaluated by calculating the bus power margin. The hardware's condition can also be evaluated based on the aging of the hardware structure. Furthermore, the comprehensive score for the health status index can be adjusted according to the fault type indicated by the device fault codes.

[0100] If the overall score decreases, it can be assumed that there is a possibility of operational abnormality. In other words, it can be determined that the preset triggering conditions are met, thereby controlling the preset process of switching the rotor device start-up mode.

[0101] If the overall score is less than the preset health threshold, that is, if the health index is less than the preset health threshold, the current driving channel is considered to be operating abnormally, that is, the switching trigger condition is met, and the switching steps are started.

[0102] Alternatively, if the fault code of the device can directly confirm that it is currently in an abnormal operating state, then the switching trigger condition can be met, and the switching steps can be started.

[0103] If the upper limit of the output power, that is, the bus power margin, is less than the target power value, it indicates that the current drive channel power is limited, and the controller 60 can start the degraded safe operation process according to the control strategy.

[0104] In summary, in this embodiment, to address complex situations such as changes in thrust demand (e.g., a step increase in thrust demand during the sudden loading phase and a step decrease in thrust demand during the sudden unloading phase) or changes in wind gusts, mode switching can significantly improve system safety and reliability. Furthermore, a preset mode switching procedure is initiated before mode switching to provide a control margin. During mode switching, by synchronously adjusting the pitch angle and electromagnetic torque, and maintaining a smooth and continuous electromagnetic torque output, torque spikes can be avoided, ensuring relatively stable rotational speed and preventing issues such as speed dips or sudden thrust changes.

[0105] Figure 4 This is a flowchart of a rotor device control method provided in an embodiment of this application.

[0106] Combination Figure 2 The rotor device includes blades 10, a pitch actuator 20, a propulsion motor 30, a first inverter 41, and a second inverter 42. The pitch actuator 20 is used to adjust the pitch angle of the blades 10, and the propulsion motor 30 is used to drive the blades 10, including a first winding 31 and a second winding 32. The first inverter 41 and the second inverter 42 are respectively used to adjust the electromagnetic torque of the first winding 31 and the second winding 32. The first inverter 41 and the first winding 31 form a first drive channel 51, and the second inverter 42 and the second winding 32 form a second drive channel 52.

[0107] In this embodiment of the application, the steps of the control method can be executed by the aforementioned controller 60.

[0108] The control method includes the following steps S1 to S2: Step S1: If the preset trigger conditions are met, start the mode switching preset process to reserve control margin for mode switching.

[0109] Step S2: If the switching trigger condition is met, perform a switch from the current drive channel to the target drive channel. This switching process includes: using torque gradient control to coordinate the electromagnetic torque outputs of the two drive channels and maintain continuous total torque; and controlling the pitch actuator 20 to adjust the blade pitch angle based on the torque change, so that the change in blade speed 10 is less than a preset threshold.

[0110] Based on this, risk assessment is performed in advance and a pre-set mode switching procedure is initiated before any operational anomaly occurs. This allows for a rapid response upon confirmation of an operational anomaly, ensuring control capability during the response phase. During the mode switching process after confirming an operational anomaly, the electromagnetic torque and pitch angle of the two drive channels are coordinated to ensure continuous electromagnetic torque variation, avoiding torque gaps and spikes, and preventing issues such as speed drops or sudden thrust changes. This enables seamless switching of operating modes, improving safety and reliability.

[0111] Figure 5 This is a schematic diagram of the structure of an aircraft provided in an embodiment of this application.

[0112] The aircraft includes multiple rotor units 100 as described in any of the above embodiments and a coordinating distributor 200. The coordinating distributor 200 is used to send a thrust command signal to each rotor unit 100, so that the controller 60 adjusts the pitch angle and electromagnetic torque of the corresponding rotor unit according to the thrust command signal.

[0113] For example, the aircraft may include four rotor units arranged in a square configuration. Alternatively, the multiple rotor units of the aircraft may be coaxially arranged.

[0114] During different mission phases, the coordinating distributor 200 can send corresponding thrust command signals to each rotor unit to enable each rotor unit to reach the corresponding target rotational speed. The target rotational speed can be different in different mission phases.

[0115] Alternatively, the coordinating distributor 200 can acquire the output capacity of each rotor unit, and in order to adapt the load distribution and safety margin, it can control different rotor units to correspond to different target speeds during the same mission phase.

[0116] In this embodiment, the cooperative distributor 200 works in conjunction with the controller 60 in each rotor device to maintain rotational speed stability and reduce the impact of disturbance factors on flight attitude and safety when faced with changes in thrust demand or gusts and environmental changes.

[0117] Before and after switching operating modes, by reserving control margin through preset processes and by controlling the two drive channels to change continuously and collaboratively through torque gradient control, a seamless switching of operating modes can be achieved, which helps to suppress problems such as speed dips and torque spikes.

[0118] The aerodynamic disturbance prediction and correction function of the controller 60 also enables the rotor device to achieve adaptive parameter adjustment and feedforward compensation during complex wind fields and mission phase changes, which is beneficial to improving robustness and long-term consistency.

[0119] After the controller 60 performs controllable thrust calculation, the cooperative distributor 200 performs cooperative control of multiple rotor devices according to the output capacity of each rotor device, controlling the rotor devices to perform variable pitch unloading or loading, so as to keep the thrust of each rotor device controllable and safe.

[0120] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the control method described in the above embodiments.

[0121] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the control method described in the above embodiments. For example, the computer-readable storage medium may be ROM, Flash memory, eMMC flash memory, solid-state drive (SSD), and hard disk drive (HDD), etc.

[0122] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0123] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention filed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not claimed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0124] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

[0125] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A rotor device, characterized in that, include: Paddle blades; A variable pitch actuator is used to adjust the pitch angle of the blades; A propulsion motor for driving the blades includes a first winding and a second winding; The first inverter and the second inverter are used to adjust the electromagnetic torque of the first winding and the second winding, respectively; The first inverter and the first winding form a first drive channel, and the second inverter and the second winding form a second drive channel; as well as The controller is connected to the variable pitch actuator, the first inverter, and the second inverter; Used to initiate a preset mode switching process when preset trigger conditions are met, adjust electromagnetic torque and / or pitch angle, and reserve control margin for mode switching; And if the switching triggering conditions are met, perform a switch from the current driving channel to the target driving channel; The switching process includes: The electromagnetic torque output from the two drive channels is coordinated and varied by torque gradient control to maintain continuous total torque. The pitch actuator is controlled to adjust the pitch angle according to the torque variation so that the change in blade speed is less than a preset change threshold. The step of controlling the pitch actuator to adjust the pitch angle according to the torque change includes: determining the short-time load torque based on the available margin of electromagnetic torque, and determining the pitch angle based on the short-time load torque.

2. The rotor device according to claim 1, characterized in that, The controller is also configured to, during the mode switching preset process or during the switching process, control the synchronous electrical angle and current of the two drive channels to enter a synchronous hot standby state.

3. The rotor device according to claim 1, characterized in that, The controller is also configured to acquire at least one of the following parameters after the switching process is completed: The current of the drive channel, the internal temperature rise, the error between the actual speed of the propulsion motor and the target speed value, and the error between the actual thrust of the rotor device and the target thrust value; Furthermore, if the parameters do not meet the corresponding preset security threshold, a downgraded security operation process is initiated.

4. The rotor device according to claim 3, characterized in that, The controller is also configured to, during the initiation of the degradation security operation process: Based on the preset drive channel constraints, determine the current available electromagnetic torque value of the rotor device; The controllable thrust range is determined based on the preset pitch angle and speed constraints, disturbance correction constraints, and the available electromagnetic torque value. Adjust the target blade rotation speed so that the actual thrust of the rotor assembly is within the controllable thrust range; or... If the maximum value of the controllable thrust range is less than the preset safe thrust value, the emergency response procedure will be initiated.

5. The rotor device according to claim 1, characterized in that, The controller is also configured to: Based on changes in environmental wind conditions, predict the load torque disturbance value and thrust disturbance value; Based on the load torque disturbance value and the thrust disturbance value, determine the pitch angle compensation value and the torque compensation value; The pitch angle and the electromagnetic torque are adjusted based on the pitch angle compensation value and the torque compensation value.

6. The rotor device according to claim 1, characterized in that, The controller is also configured to: Monitor the current task phase and the health metrics of each drive channel; If the health index of at least one drive channel is detected to be declining, and / or if the current task stage is detected to be a preset high-risk task stage, the preset trigger condition is determined to be met. The high-risk mission phases include at least one of the following: take-off and landing phase, hoisting phase, sudden loading phase, sudden unloading phase, and working phase in strong gust wind zone.

7. The rotor device according to claim 6, characterized in that, The controller is also used to monitor the upper limit of the output power and device fault codes for each drive channel; If the health index is detected to be less than the preset health threshold, and / or if the upper limit of the output power is detected to be less than the target power value, and / or if the device fault code is detected, it is determined that the switching trigger condition is met.

8. The rotor device according to claim 6, characterized in that, The controller is also configured to acquire at least one of the following parameters: Ambient temperature, ambient wind speed, load gravity, load torque, device fault codes, flight speed, actual rotation speed, electrical angle, current, voltage, winding open circuit characteristics, winding short circuit characteristics, and device internal temperature; The health index is determined based on the parameters.

9. A control method for a rotor device, characterized in that, The rotor assembly includes: Paddle blades; A variable pitch actuator is used to adjust the pitch angle of the blades; A propulsion motor for driving the blades includes a first winding and a second winding; The first inverter and the second inverter are used to adjust the electromagnetic torque of the first winding and the second winding, respectively; the first inverter and the first winding form a first drive channel, and the second inverter and the second winding form a second drive channel; The control method includes: Under the condition that the preset triggering conditions are met, the preset mode switching process is started, and the electromagnetic torque and / or pitch angle are adjusted to reserve control margin for mode switching. If the switching trigger condition is met, a switch is performed from the current driving channel to the target driving channel; the switching process includes: The electromagnetic torque output from the two drive channels is coordinated and varied by torque gradient control to maintain continuous total torque. The pitch actuator is controlled to adjust the pitch angle according to the torque variation so that the change in blade speed is less than a preset change threshold. The step of controlling the pitch actuator to adjust the pitch angle according to the torque change includes: determining the short-time load torque based on the available margin of electromagnetic torque, and determining the pitch angle based on the short-time load torque.

10. An aircraft, characterized in that, include: Multiple rotor devices as described in any one of claims 1-8; A coordinated distributor is used to send thrust command signals to each rotor unit, so that the controller adjusts the pitch angle and electromagnetic torque of the corresponding rotor unit according to the thrust command signals.

11. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in claim 9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in claim 9.

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