Control method, device and related equipment of coaxial multi-rotor aircraft

Abstract

This disclosure provides a control method, apparatus, and related equipment for a coaxial multirotor aircraft. The method includes: constructing a first objective function based on the single-axis thrust of each axis of the coaxial multirotor aircraft and the roll moment, pitch moment, and lift of the aircraft; constructing a second objective function based on the single-axis torque of each axis and the yaw moment of the aircraft; minimizing the first objective function to obtain the single-axis thrust of each axis; minimizing the second objective function to obtain the single-axis torque of each axis; obtaining the rotational speed of each rotor on each axis based on the single-axis thrust and torque of each axis through a coaxial thrust and torque model; and controlling the coaxial multirotor aircraft based on the rotational speed of the rotors on each axis. Through the above technical means, the problem of aerodynamic interaction in coaxial multirotor aircraft, which cannot be addressed by existing technologies, is solved.

Description

Technical Field

[0001] This disclosure relates to the field of unmanned aerial vehicle (UAV) control technology, and in particular to a control method, device, and related equipment for a coaxial multi-rotor aircraft. Background Technology

[0002] With the rapid development of drone technology, coaxial multirotor aircraft have attracted attention due to their greater payload capacity. However, the aerodynamic interaction between the upper and lower rotors on the same axis in a coaxial multirotor aircraft disrupts the stable correlation between thrust, torque, and rotational speed, resulting in a non-linear relationship between rotational speed and thrust / torque. Traditional control methods cannot effectively address this problem in coaxial multirotor aircraft, causing them to fail to fully utilize the advantages of multiple rotors, and instead, the multiple rotors may even hinder each other. Summary of the Invention

[0003] This disclosure provides a control method, apparatus, electronic device, and computer-readable storage medium for a coaxial multirotor aircraft, which at least to some extent improves user safety.

[0004] Other features and advantages of this disclosure will become apparent from the following detailed description, or may be learned in part by practice of this disclosure.

[0005] According to one aspect of this disclosure, a control method for a coaxial multirotor aircraft is provided, comprising: constructing a first objective function based on the single-axis thrust of each axis of the coaxial multirotor aircraft and the roll moment, pitch moment, and lift of the aircraft body; constructing a second objective function based on the single-axis torque of each axis and the yaw moment of the aircraft body; minimizing the first objective function to obtain the single-axis thrust of each axis; minimizing the second objective function to obtain the single-axis torque of each axis; obtaining the rotational speed of the rotors on each axis based on the single-axis thrust and single-axis torque of each axis through a coaxial thrust and torque model; and controlling the coaxial multirotor aircraft based on the rotational speed of the rotors on each axis.

[0006] In one embodiment of this disclosure, a first objective function is constructed using the single-axis thrust of each axis and the roll moment, pitch moment, and lift of the coaxial multirotor aircraft. This includes: constructing a thrust matrix using the single-axis thrust of each axis; calculating the resultant force of all single-axis thrusts as lift; constructing a first desired matrix using the roll moment, pitch moment, and lift; and constructing the first objective function using the thrust matrix, the first desired matrix, and the hybrid control matrix of the coaxial multirotor aircraft.

[0007] In one embodiment of this disclosure, the first objective function is expressed as:

[0008] Φ(F)=F T F+(DF-V) T W(DF-V);

[0009] F = [f1, f2, ..., fc] T ;

[0010] V = [R, P, H];

[0011] Where R, P, and H are the rolling moment, pitching moment, and lift, respectively; V is the first desired matrix; F is the tension matrix, which is a one-dimensional vector of length c representing the single-axis tension of each axis; T is the transpose symbol; D is the mixed control matrix; and W is the preset first matrix.

[0012] In one embodiment of this disclosure, a second objective function is constructed based on the single-axis torque of each axis and the yaw moment of the fuselage, including: constructing a torque matrix using the single-axis torque of each axis; calculating the resultant torque of all single-axis torques; constructing a second expectation matrix using the yaw moment and the resultant torque; and constructing the second objective function using the torque matrix and the second expectation matrix.

[0013] In one embodiment of this disclosure, the second objective function is expressed as:

[0014]

[0015] M = [m1, m2, ..., mc] T ;

[0016] Where M is the torque matrix, a one-dimensional vector of length c representing the single-axis torque, T is the transpose, J is the resultant torque, and Y is the yaw moment. This represents the square of the L2 norm, where λ is a predefined coefficient.

[0017] In one embodiment of this disclosure, minimizing the second objective function to obtain the single-axis torque of each axis includes: obtaining the torque feasible region of the single-axis torque of each axis based on the single-axis tension of each axis through a coaxial tension and torque model; and minimizing the second objective function to obtain the single-axis torque of each axis under the condition that the single-axis torque of each axis is within the torque feasible region.

[0018] In one embodiment of this disclosure, the method further includes: constructing a tension matrix using the single-axis tension of each axis; constructing a torque matrix using the single-axis torque of each axis; constructing a rotational speed matrix using the rotational speed of the rotors of each axis; and constructing a coaxial tension and torque model using the tension matrix, torque matrix, and rotational speed matrix.

[0019] In one embodiment of this disclosure, two rotors are mounted on each shaft, and the thrust matrix is ​​represented as F = [F1…Fi…Fc]. T The torque matrix is ​​represented as M = [M1…Mi…Mc]. T ;in,

[0020]

[0021] T is the transpose symbol, A1, A2, B1, and B2 are the preset second, third, fourth, and fifth matrices, respectively, c is the number of axes of the coaxial multirotor, Fi is the single-axis thrust of the i-th axis of the coaxial multirotor, Mi is the single-axis torque of the i-th axis of the coaxial multirotor, ri1 is the rotational speed of the first rotor on the i-th axis of the coaxial multirotor, and ri2 is the rotational speed of the second rotor on the i-th axis of the UAV.

[0022] According to another aspect of this disclosure, a control device for a coaxial multirotor aircraft is provided, comprising: a first construction module configured to construct a first objective function based on the single-axis thrust of each axis of the coaxial multirotor aircraft and the roll moment, pitch moment, and lift of the aircraft body; a second construction module configured to construct a second objective function based on the single-axis torque of each axis and the yaw moment of the aircraft body; a first planning module configured to minimize the first objective function to obtain the single-axis thrust of each axis; a second planning module configured to minimize the second objective function to obtain the single-axis torque of each axis; an inverse solving module configured to obtain the rotational speed of the rotors on each axis based on the single-axis thrust and single-axis torque of each axis through a coaxial thrust and torque model; and a control module configured to control the coaxial multirotor aircraft based on the rotational speed of the rotors on each axis.

[0023] According to another aspect of this disclosure, an electronic device is provided, comprising: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to perform any of the above-described control methods by executing the executable instructions.

[0024] According to another aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements any of the control methods described above.

[0025] In the embodiments of this disclosure, the single-axis thrust of each axis is obtained by minimizing the first objective function, and the single-axis torque of each axis is obtained by minimizing the second objective function. Based on the single-axis thrust and single-axis torque of each axis, the rotational speed of the rotor on each axis is obtained through a coaxial thrust and torque model. By using the above technical means, the problem of aerodynamic interaction in coaxial multi-rotor aircraft that the prior art cannot deal with is solved, thereby improving control efficiency.

[0026] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0028] Figure 1 A flowchart illustrating a control method for a coaxial multirotor aircraft according to an embodiment of this disclosure is shown.

[0029] Figure 2 A flowchart illustrating a method for constructing a first objective function according to an embodiment of this disclosure is shown.

[0030] Figure 3 A flowchart illustrating a method for constructing a second objective function according to an embodiment of this disclosure is shown.

[0031] Figure 4 A flowchart illustrating a method for solving a single-axis torque according to an embodiment of this disclosure is shown.

[0032] Figure 5 A flowchart illustrating a method for constructing a coaxial tension and torque model according to an embodiment of this disclosure is shown.

[0033] Figure 6 A schematic diagram of a control device for a coaxial multirotor aircraft according to an embodiment of the present disclosure is shown.

[0034] Figure 7 A schematic diagram of an electronic device provided in an embodiment of this disclosure is shown. Detailed Implementation

[0035] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0036] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0037] It should be understood that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0038] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0039] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0040] It should be noted that, unless otherwise specified, the embodiments of this disclosure and the technical features thereof can be combined with each other.

[0041] The specific implementation methods of the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0042] Definitions:

[0043] Rotational speed refers to the number of revolutions a rotor makes per minute or per second, usually expressed in RPM (Revolutions Per Minute) or rad / s (radians per second). Rotational speed directly affects the thrust generated by the rotor, usually expressed in Newtons (N). Torque refers to the reaction torque generated by the rotor on the aircraft fuselage during rotation, usually expressed in Newton-meters (N·m).

[0044] Coaxial multirotor aircraft: This refers to a specially designed aircraft characterized by having multiple rotors arranged coaxially. A coaxial multirotor aircraft has multiple axes, each with multiple pairs of upper and lower rotors (the number of rotors on each axis is always an even number). These rotors work together to control the aircraft's attitude and movement. Common coaxial multirotor aircraft include biaxial quadcopters and quadcopters with octagonal rotors, where each quadcopter has two rotors (upper and lower) on one axis.

[0045] A mixing matrix for drones typically refers to a method used in multi-rotor drones or multi-servo control systems to translate control commands from the flight controller into specific output signals for each motor or servo. This conversion needs to take into account different types of drone designs and their power layouts, ensuring that each motor or servo operates as intended to achieve stable flight and precise control.

[0046] Figure 1This diagram illustrates a flowchart of a control method for a coaxial multirotor aircraft according to an embodiment of the present disclosure. The method is as follows: Figure 1 As shown, it includes the following steps:

[0047] S101, construct the first objective function based on the single-axis thrust of each axis on the coaxial multirotor aircraft and the rolling moment, pitching moment and lift of the coaxial multirotor aircraft body;

[0048] Single-axis thrust: refers to the resultant force in the vertical direction generated by all rotors on a single axis, used to overcome gravity to enable the aircraft to ascend or maintain a hovering state. Roll moment and pitch moment: refer to the moments required for rotation about the aircraft's lateral (roll) and longitudinal (pitch) axes, respectively, affecting the aircraft's tilt angle and forward / reverse movements. First objective function: a mathematical model constructed based on the single-axis thrust of each axis and the roll and pitch moments of the airframe, aiming to optimize thrust distribution to achieve balance and stability.

[0049] The first objective function is constructed based on the single-axis tension, roll moment, pitch moment, and lift of each axis. This technique enhances the aircraft's ability to maintain balance in the air, improves the accuracy of attitude adjustment, and enhances flight safety and stability.

[0050] S102, a second objective function is constructed based on the single-axis torque of each axis and the yaw moment of the airframe. Single-axis torque: the torque generated by all rotors on a single axis, used to generate yaw (i.e., rotation about the vertical axis). Yaw moment: the torque required for rotation about the aircraft's vertical axis, affecting the aircraft's left and right turning. The second objective function: a mathematical model constructed based on the single-axis torque of each axis and the yaw moment of the airframe, used to optimize torque distribution and achieve precise directional control.

[0051] A second objective function is constructed based on the single-axis torque and yaw moment of each axis. This process addresses the aircraft's directional control problem by establishing a suitable mathematical model to solve the challenges that may be encountered during yaw. S103, minimize the first objective function to obtain the single-axis thrust of each axis;

[0052] The single-axis thrust of each axis can be minimized using quadratic programming. This technique finds the optimal thrust distribution scheme, ensuring the aircraft can smoothly perform various flight missions. Quadratic programming (QP) is a special type of optimization method where the objective function is quadratic, while the constraints can be linear.

[0053] S104, minimize the second objective function to obtain the single-axis torque of each axis;

[0054] The torque generated by each rotor is determined by minimizing the second objective function using quadratic programming. This enables precise adjustment of the aircraft's directional control, improves maneuverability, and allows the aircraft to accurately perform steering maneuvers in complex environments.

[0055] S105, based on the single-axis tension and single-axis torque of each axis, obtains the rotational speed of the rotor on each axis through a coaxial tension and torque model;

[0056] The coaxial thrust and torque model is a computational model that determines the rotational speed of each rotor by inputting thrust and torque parameters, thereby achieving precise control of the aircraft. This process is directly related to how to translate theoretical calculations into actual physical control signals, ensuring that the aircraft can fly according to the predetermined plan.

[0057] S106 is a coaxial multirotor aircraft whose rotational speed is controlled based on the rotational speed of the rotors on each axis.

[0058] According to the technical solution provided in this disclosure, a first objective function is constructed based on the single-axis thrust of each axis of the coaxial multirotor aircraft and the roll moment, pitch moment, and lift of the aircraft. A second objective function is constructed based on the single-axis torque of each axis and the yaw moment of the aircraft. The first objective function is minimized to obtain the single-axis thrust of each axis. The second objective function is minimized to obtain the single-axis torque of each axis. Based on the single-axis thrust and torque of each axis, the rotational speed of the rotors on each axis is obtained through a coaxial thrust and torque model. The coaxial multirotor aircraft is controlled based on the rotational speed of the rotors on each axis. Through the above technical means, the problem of aerodynamic interaction in coaxial multirotor aircraft that cannot be addressed by existing technologies is solved, thereby improving control efficiency.

[0059] For example, suppose a coaxial multirotor aircraft needs to search for missing persons in a complex mountainous environment during a search and rescue mission. Using the above-mentioned technical solution, a first objective function is first constructed based on the aircraft's current state (including the gravity it needs to overcome, and the desired roll and pitch angles). An optimization algorithm then finds the most suitable single-axis thrust distribution scheme to ensure stable flight and prevent the aircraft from losing balance due to terrain changes. Next, to cope with constantly changing wind direction and speed, the system dynamically adjusts the parameters in the second objective function to precisely control the aircraft's direction, ensuring it accurately follows the preset path. Throughout this process, the coaxial thrust and torque model calculates the optimal rotational speed of each rotor in real time, thus guaranteeing the safe and efficient completion of the entire flight mission.

[0060] Figure 2 This diagram illustrates a flowchart of a method for constructing a first objective function according to an embodiment of the present disclosure. The method is as follows: Figure 2 As shown, it includes the following steps:

[0061] S201, constructs a tension matrix using the uniaxial tension of each axis;

[0062] S202, calculate the resultant force of all uniaxial tensions as lift;

[0063] S203, using roll moment, pitch moment and lift to construct the first desired matrix;

[0064] S204 uses the tension matrix, the first expectation matrix, and the mixing matrix of the coaxial multi-rotor aircraft to construct the first objective function.

[0065] The thrust matrix represents the single-axis thrust of each axis. The first desired matrix represents the lift, roll moment, and pitch moment, designed to reflect the conditions that the aircraft must meet to achieve the desired attitude adjustments (such as tilt angle or forward / reverse). The control matrix describes the control mechanism of a coaxial multirotor aircraft, relating the physical effects of the rotors (such as thrust and torque) to the actual motions of the aircraft (such as displacement and rotation). This matrix is ​​crucial for achieving precise flight control. The control matrix of a coaxial multirotor aircraft is constructed based on the physical structure of the aircraft; constructing the control matrix is ​​a common technique and will not be elaborated upon here.

[0066] In this embodiment, a thrust matrix is ​​first constructed using the single-axis thrust of each axis, enhancing the understanding and management of the output force of each rotor and improving control precision. Next, the resultant force of all single-axis thrust is calculated as lift, and combined with roll moment, pitch moment, and lift to construct a first desired matrix, ensuring the aircraft can rapidly adjust its attitude according to environmental changes and improving flight stability. Finally, a first objective function is constructed using the thrust matrix, the first desired matrix, and the hybrid control matrix of the coaxial multi-rotor aircraft. These techniques effectively solve the force distribution problem, enabling the aircraft to maintain optimal performance when performing complex tasks.

[0067] For example, in a search and rescue operation, a coaxial multirotor aircraft needs to maintain stable flight under high wind speeds. By constructing a thrust matrix to accurately grasp the thrust of each rotor and calculating the resultant force of all single-axis thrusts, a first desired matrix can be formulated. In this way, even in the face of strong wind interference, the aircraft can maintain balance by precisely adjusting its roll and pitch angles. The first objective function constructed in conjunction with the mixing matrix ensures that the aircraft can efficiently perform search missions in complex environments.

[0068] In some embodiments, genetic algorithms or other heuristic algorithms can be used instead of quadratic programming methods. For example, a fitness function can be defined to evaluate the effectiveness of different thrust distribution schemes, and the optimal thrust distribution can be found iteratively by simulating the process of natural selection. By exploring a wider solution space, it is possible to discover more effective control strategies, thereby further improving the performance and flexibility of the aircraft. In addition, a real-time data feedback mechanism can be considered to dynamically adjust parameters based on the actual flight performance of the aircraft to adapt to constantly changing mission requirements.

[0069] In one embodiment of this disclosure, the first objective function is expressed as:

[0070] Φ(F)=F T F+(DF-V) T W(DF-V); (1)

[0071] F = [f1, f2, ..., fc] T (2)

[0072] V = [R, P, H]; (3)

[0073] Where R, P, and H are the rolling torque, pitching torque, and lift, respectively; V is the first desired matrix; F is the pull matrix; c is the number of axes of the UAV; fc is the single-axis pull of the c-th axis of the UAV; T is the transpose symbol; D is the hybrid control matrix; and W is the preset first matrix.

[0074] The tension matrix is ​​a one-dimensional vector of length c, representing the uniaxial tension along each axis.

[0075] V represents the desired roll moment, pitch moment, and lift, while DF represents the actual roll moment, pitch moment, and lift. Therefore, solving the first objective function can be understood as minimizing the differences between the actual roll moment, pitch moment, and lift and the desired roll moment, pitch moment, and lift. The first matrix can be obtained using a large amount of historical flight data from the aircraft.

[0076] Figure 3 This diagram illustrates a flowchart of a method for constructing a second objective function according to an embodiment of the present disclosure. The method is as follows: Figure 3 As shown, it includes the following steps:

[0077] S301, constructs a torque matrix using the single-axis torque of each axis;

[0078] S302, calculate the sum of all single-axis torques;

[0079] S303, using yaw moment and resultant torque to construct the second desired matrix;

[0080] S304, using the torque matrix and the second expectation matrix to construct the second objective function.

[0081] The torque matrix represents the matrix of single-axis torques generated by the rotors on each axis. The resultant torque is the sum of all single-axis torques and is used to describe the overall ability of the aircraft to rotate about the vertical axis, directly affecting the yaw effect. The second expectation matrix reflects the conditions that the aircraft needs to meet in order to achieve the desired directional control (such as left and right turns).

[0082] In this embodiment, a torque matrix is ​​first constructed using the single-axis torques of each axis. This process quantifies the torque generated by the rotor on each axis, providing fundamental data support for subsequent calculations. Next, the sum of all single-axis torques is calculated, and a second desired matrix is ​​constructed by combining it with the yaw moment. This technique enhances the understanding and management of aircraft directional control and improves the accuracy of yaw adjustments. Finally, a second objective function is constructed using the torque matrix and the second desired matrix. Through these techniques, the aircraft's maneuverability in complex environments is improved, ensuring its efficient completion of various tasks.

[0083] For example, in a search and rescue operation, a coaxial multirotor aircraft needs to maneuver flexibly in a narrow valley to avoid obstacles. By constructing a torque matrix to accurately grasp the torque output of each rotor and calculating the resultant torque of all single-axis torques, a second desired matrix can be formulated. This allows the aircraft to quickly change direction by precisely adjusting the yaw angle, even in the face of strong winds or sudden obstacles. Combining the optimization results of the second objective function ensures that the aircraft can safely and efficiently perform search missions in complex environments.

[0084] In some embodiments, machine learning algorithms can be introduced to optimize the construction process of the second objective function. For example, a model can be trained using reinforcement learning to automatically adjust the torque distribution strategy based on the aircraft's historical data. Specific implementations include defining a reward function to evaluate the effectiveness of different torque distribution schemes and iteratively optimizing the model parameters through simulated flight missions. While this approach requires a large amount of data and computational resources, by exploring a broader solution space, it is possible to discover more efficient control strategies, thereby further improving the aircraft's directional control capabilities. Furthermore, a real-time sensor feedback mechanism can be considered to dynamically adjust the torque distribution based on the aircraft's actual flight performance to adapt to constantly changing mission requirements.

[0085] In one embodiment of this disclosure, the second objective function is expressed as:

[0086]

[0087] M = [m1, m2, ..., mc] W (5)

[0088] Where c is the number of axes of the UAV, mc is the single-axis torque of the c-th axis of the UAV, M is the torque matrix, T is the transpose sign, J is the resultant torque, and Y is the yaw moment. This represents the square of the L2 norm, where λ is a predefined coefficient.

[0089] The torque matrix is ​​a one-dimensional vector of length c, representing the single-axis torque of each axis.

[0090] J can represent the actual yawing moment, and Y can represent the desired yawing moment. Therefore, solving the second objective function can be understood as minimizing the difference between the actual yawing moment and the desired yawing moment.

[0091] Figure 4 This diagram shows a flowchart of a single-axis torque calculation method according to an embodiment of the present disclosure. The method is as follows: Figure 4 As shown, it includes the following steps:

[0092] S401, based on the single-axis tension of each axis, obtains the torque feasible region of the single-axis torque of each axis through the coaxial tension and torque model;

[0093] S402, under the condition that the single-axis torque of each axis is within the torque feasible region, minimize the second objective function to obtain the single-axis torque of each axis.

[0094] The uniaxial tension of each axis can be substituted into the coaxial tension and torque model to solve for the upper boundary (maximum value) and lower boundary (minimum value) of the uniaxial torque. The feasible region of torque is the range between this maximum and minimum value. The solved uniaxial torque of each axis lies within the feasible region of torque. Minimizing the second objective function yields the uniaxial torque of each axis. This technique improves the accuracy of solving for uniaxial torque.

[0095] Figure 5 This diagram illustrates a flowchart of a method for constructing a coaxial tension and torque model according to an embodiment of the present disclosure. The method is as follows: Figure 5 As shown, it includes the following steps:

[0096] S501, constructs a tension matrix using the uniaxial tension of each axis;

[0097] S502 uses the single-axis torque of each axis to construct a torque matrix;

[0098] S503 constructs a rotational speed matrix using the rotational speeds of the rotors on each shaft;

[0099] S504 uses the force matrix, torque matrix, and speed matrix to construct a coaxial force and torque model.

[0100] The rotational speed matrix is ​​used to represent the rotational speed of each rotor on each coaxial axis.

[0101] In this embodiment, firstly, a thrust matrix is ​​constructed using the single-axis thrust of each axis. This step provides fundamental data support for subsequent calculations regarding the vertical forces generated by each rotor. Next, a torque matrix is ​​constructed using the single-axis torque of each axis. This step aims to quantify the impact of each coaxial rotor on the aircraft's yaw control. Subsequently, a rotational speed matrix is ​​constructed using the rotational speeds of each rotor on each axis. This process is crucial for understanding the operating state of each rotor, as the rotor's rotational speed directly affects the thrust and torque it generates. Finally, a coaxial thrust and torque model is constructed using the thrust matrix, torque matrix, and rotational speed matrix. Through these technical means, the understanding of the overall mechanical behavior of the aircraft is enhanced, the accuracy of attitude and direction control is improved, and flight performance and safety are enhanced.

[0102] For example, in a complex mountain search and rescue mission, a coaxial multirotor aircraft needs to perform high-precision movement and turning within confined spaces. A thrust matrix is ​​constructed to accurately monitor the thrust output of each rotor, ensuring the aircraft can hover stably or move along a predetermined trajectory. Simultaneously, a torque matrix is ​​constructed to manage the torque contribution of each rotor, enabling the aircraft to quickly adjust its direction when necessary. Furthermore, a rotational speed matrix is ​​used to monitor and adjust the rotational speed of each rotor to adapt to constantly changing mission requirements. Based on these three matrices, the coaxial thrust and torque model can calculate the optimal rotor speed combination in real time, ensuring the aircraft efficiently completes search and rescue missions.

[0103] In one embodiment of this disclosure,

[0104] Two rotors are mounted on each shaft, and the thrust matrix is ​​represented as F = [F1…Fi…Fc]. T The torque matrix is ​​represented as M = [M1…Mi…Mc]. T ;in, Xi = [ri1, ri2] T ;

[0105] T is the transpose symbol, A1, A2, B1, and B2 are the preset second, third, fourth, and fifth matrices, respectively, c is the number of axes of the coaxial multirotor, Fi is the single-axis thrust of the i-th axis of the coaxial multirotor, Mi is the single-axis torque of the i-th axis of the coaxial multirotor, ri1 is the rotational speed of the first rotor on the i-th axis of the coaxial multirotor, and ri2 is the rotational speed of the second rotor on the i-th axis of the UAV.

[0106] The second, third, fourth, and fifth matrices can be calibrated using a large amount of historical flight data from the aircraft.

[0107] Based on the same inventive concept, this disclosure also provides a control device for a coaxial multirotor aircraft, as shown in the following embodiment. Since the principle by which this device solves the problem is similar to that of the method embodiment described above, the implementation of this device embodiment can refer to the implementation of the method embodiment described above, and repeated details will not be elaborated further.

[0108] Figure 6 This diagram illustrates a control device for a coaxial multirotor aircraft according to an embodiment of the present disclosure, such as... Figure 6 As shown, the control device for this coaxial multi-rotor aircraft may include:

[0109] The first construction module 601 is configured to construct a first objective function based on the single-axis thrust of each axis on the coaxial multirotor aircraft and the roll moment, pitch moment and lift of the coaxial multirotor aircraft body;

[0110] The second construction module 602 is configured to construct a second objective function based on the single-axis torque of each axis and the yaw moment of the fuselage;

[0111] The first planning module 603 is configured to minimize the first objective function to obtain the uniaxial tension of each axis;

[0112] The second planning module 604 is configured to minimize the second objective function to obtain the single-axis torque of each axis;

[0113] The inverse solver module 605 is configured to obtain the rotor speed on each axis based on the single-axis tension and single-axis torque of each axis through the coaxial tension and torque model;

[0114] The control module 606 is configured to control a coaxial multirotor aircraft based on the rotational speed of the rotors on each axis.

[0115] According to the technical solution provided in this disclosure, a first objective function is constructed based on the single-axis thrust of each axis of the coaxial multirotor aircraft and the roll moment, pitch moment, and lift of the aircraft. A second objective function is constructed based on the single-axis torque of each axis and the yaw moment of the aircraft. The first objective function is minimized to obtain the single-axis thrust of each axis. The second objective function is minimized to obtain the single-axis torque of each axis. Based on the single-axis thrust and torque of each axis, the rotational speed of the rotors on each axis is obtained through a coaxial thrust and torque model. The coaxial multirotor aircraft is controlled based on the rotational speed of the rotors on each axis. Through the above technical means, the problem of aerodynamic interaction in coaxial multirotor aircraft that cannot be addressed by existing technologies is solved, thereby improving control efficiency.

[0116] In some embodiments, the construction module 601 is further configured to construct a thrust matrix using the single-axis thrust of each axis; calculate the resultant force of all single-axis thrusts as lift; construct a first desired matrix using roll moment, pitch moment and lift; and construct a first objective function using the thrust matrix, the first desired matrix and the hybrid control matrix of the coaxial multirotor aircraft.

[0117] In some embodiments, the construction module 601 is further configured to replace quadratic programming with genetic algorithms or other heuristic algorithms, such as defining a fitness function to evaluate the effectiveness of different thrust distribution schemes and iteratively finding the optimal thrust distribution by simulating a natural selection process. By exploring a wider solution space, it is possible to discover more effective control strategies, thereby further improving the performance and flexibility of the aircraft. Furthermore, a real-time data feedback mechanism can be considered to dynamically adjust parameters based on the aircraft's actual flight performance to adapt to constantly changing mission requirements.

[0118] The first objective function is expressed as:

[0119] Φ(F) = FTF + (DF - V) T W(DF-V); (1)

[0120] F = [f1, f2, ..., fc] T (2)

[0121] V = [R, P, H]; (3)

[0122] Where R, P, and H are the rolling torque, pitching torque, and lift, respectively; V is the first desired matrix; F is the pull matrix; c is the number of axes of the UAV; fc is the single-axis pull of the c-th axis of the UAV; T is the transpose symbol; D is the hybrid control matrix; and W is the preset first matrix.

[0123] In some embodiments, the construction module 601 is further configured to construct a torque matrix using the single-axis torques of each axis; calculate the resultant torque of all single-axis torques; construct a second desired matrix using the yaw moment and the resultant torque; and construct a second objective function using the torque matrix and the second desired matrix.

[0124] In some embodiments, the construction module 601 is also configured to introduce machine learning algorithms to optimize the construction process of the second objective function. For example, a model can be trained using reinforcement learning to automatically adjust the torque distribution strategy based on the aircraft's historical data. Specific implementations include defining a reward function to evaluate the effectiveness of different torque distribution schemes and iteratively optimizing the model parameters through simulated flight missions. While this approach requires a large amount of data and computational resources, it has the potential to discover more efficient control strategies by exploring a broader solution space, thereby further improving the aircraft's directional control capabilities. Furthermore, a real-time sensor feedback mechanism can be considered to dynamically adjust the torque distribution based on the aircraft's actual flight performance to adapt to constantly changing mission requirements.

[0125] The second objective function is expressed as follows:

[0126]

[0127] M = [m1, m2, ..., mc] T (5)

[0128] Where c is the number of axes of the UAV, mc is the single-axis torque of the c-th axis of the UAV, M is the torque matrix, T is the transpose sign, J is the resultant torque, and Y is the yaw moment. This represents the square of the L2 norm, where λ is a predefined coefficient.

[0129] In some embodiments, the second planning module 603 is further configured to obtain the torque feasible region of the single-axis torque of each axis based on the single-axis tension of each axis through a coaxial tension and torque model; and to minimize the second objective function to obtain the single-axis torque of each axis under the condition that the single-axis torque of each axis is within the torque feasible region.

[0130] In some embodiments, the second planning module 603 is further configured to construct a tension matrix using the single-axis tension of each axis; construct a torque matrix using the single-axis torque of each axis; construct a speed matrix using the rotational speed of the rotors of each axis; and construct a coaxial tension and torque model using the tension matrix, torque matrix, and speed matrix.

[0131] Two rotors are mounted on each shaft, and the thrust matrix is ​​represented as F = [F1…Fi…Fc]. T The torque matrix is ​​represented as M = [M1…Mi…Mc]. T ;in, Xi = [ri1, ri2] T ;

[0132] T is the transpose symbol, A1, A2, B1, and B2 are the preset second, third, fourth, and fifth matrices, respectively, c is the number of axes of the coaxial multirotor, Fi is the single-axis thrust of the i-th axis of the coaxial multirotor, Mi is the single-axis torque of the i-th axis of the coaxial multirotor, ri1 is the rotational speed of the first rotor on the i-th axis of the coaxial multirotor, and ri2 is the rotational speed of the second rotor on the i-th axis of the UAV.

[0133] Those skilled in the art will understand that various aspects of this disclosure can be implemented as a system, method, or program product. Therefore, various aspects of this disclosure can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software aspects, collectively referred to herein as a "circuit," "module," or "system."

[0134] The following reference Figure 7 To describe an electronic device 700 according to such an embodiment of the present disclosure. Figure 7 The electronic device 700 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments disclosed herein.

[0135] like Figure 7 As shown, the electronic device 700 is manifested in the form of a general-purpose computing device. The components of the electronic device 700 may include, but are not limited to: at least one processing unit 77, at least one storage unit 720, and a bus 730 connecting different system components (including the storage unit 720 and the processing unit 77).

[0136] The storage unit stores program code, which can be executed by the processing unit 77 to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure. For example, the processing unit 77 can perform the following steps of the above method embodiment: constructing a first objective function based on the single-axis thrust of each axis of the coaxial multirotor aircraft and the roll moment, pitch moment, and lift of the coaxial multirotor aircraft; constructing a second objective function based on the single-axis torque of each axis and the yaw moment of the aircraft; minimizing the first objective function to obtain the single-axis thrust of each axis; minimizing the second objective function to obtain the single-axis torque of each axis; obtaining the rotational speed of the rotor on each axis based on the single-axis thrust and single-axis torque of each axis through a coaxial thrust and torque model; and controlling the coaxial multirotor aircraft based on the rotational speed of the rotor on each axis.

[0137] Storage unit 720 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 7201 and / or cache memory 7202, and may further include a read-only memory (ROM) 7203.

[0138] The storage unit 720 may also include a program / utility 7204 having a set (at least one) program module 7205, such program module 7205 including but not limited to: an operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0139] Bus 730 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0140] Electronic device 700 can also communicate with one or more external devices 740 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 700, and / or with any device that enables electronic device 700 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 750. Furthermore, electronic device 700 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 760. As shown, network adapter 760 communicates with other modules of electronic device 700 via bus 730. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 700, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0141] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0142] In the disclosed exemplary embodiments, a computer-readable storage medium is also provided, which may be a readable signal medium or a readable storage medium.

[0143] In some possible implementations, various aspects of this disclosure may also be implemented as a program product comprising program code that, when run on a terminal device, causes the terminal device to perform the steps described in the foregoing “Detailed Description” section of this specification according to various exemplary embodiments of this disclosure.

[0144] More specific examples of computer-readable storage media in this disclosure may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0145] In this disclosure, a computer-readable storage medium may include a data signal propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of transmitting, propagating, or transmitting a program for use by or in connection with an instruction execution system, apparatus, or device.

[0146] Optionally, the program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0147] In practical implementation, program code for performing the operations of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0148] This disclosure provides a computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the control method for a coaxial multirotor aircraft provided in various alternative embodiments of this disclosure.

[0149] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0150] Furthermore, although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0151] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, mobile terminal, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0152] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of this disclosure is indicated by the appended claims.

Claims

1. A control method for a coaxial multi-rotor aircraft, characterized in that, include: A first objective function is constructed based on the single-axis thrust of each axis on the coaxial multirotor aircraft and the rolling moment, pitching moment and lift of the coaxial multirotor aircraft. A second objective function is constructed based on the single-axis torque of each axis and the yaw moment of the fuselage; Minimize the first objective function to obtain the uniaxial tension of each axis; Minimize the second objective function to obtain the single-axis torque of each axis; Based on the single-axis tension and single-axis torque of each axis, the rotational speed of the rotor on each axis is obtained through a coaxial tension and torque model; The coaxial multirotor aircraft is controlled based on the rotational speed of the rotors on each of the axes.

2. The method according to claim 1, characterized in that, A first objective function is constructed based on the single-axis thrust of each axis of the coaxial multirotor aircraft and the roll moment, pitch moment, and lift of the aircraft's fuselage, including: A tension matrix is ​​constructed using the uniaxial tension of each axis; Calculate the resultant force of all the uniaxial tensions as the lift force; A first desired matrix is ​​constructed using the roll moment, the pitch moment, and the lift. The first objective function is constructed using the tension matrix, the first desired matrix, and the hybrid control matrix of the coaxial multi-rotor aircraft.

3. The method according to claim 2, characterized in that, The first objective function is expressed as Φ(F) = F T F+(DF-V) T W(DF-V); F=[f1,f2……fc] T ; V = [R, P, H]; Wherein, R, P, and H are the rolling torque, the pitching torque, and the lift, respectively; V is the first desired matrix; F is the tension matrix, which is a one-dimensional vector of length c representing the single-axis tension of each axis; T is the transpose symbol; D is the hybrid control matrix; and W is the preset first matrix.

4. The method according to claim 1, characterized in that, A second objective function is constructed based on the single-axis torque of each axis and the yaw moment of the airframe, including: A torque matrix is ​​constructed using the single-axis torque of each axis; Calculate the resultant torque of all the single-axis torques mentioned; A second desired matrix is ​​constructed using the yaw moment and the resultant torque; The second objective function is constructed using the torque matrix and the second desired matrix.

5. The method according to claim 4, characterized in that, The second objective function is expressed as M=[m1,m2……mc] T ; Where M is the torque matrix, which is a one-dimensional vector of length c representing the single-axis torque of each axis; T is the transpose sign; J is the resultant torque; and Y is the yaw moment. This represents the square of the L2 norm, where λ is a predefined coefficient.

6. The method according to claim 1, characterized in that, Minimizing the second objective function to obtain the single-axis torque of each axis includes: Based on the uniaxial tension of each axis, the torque feasible region of the uniaxial torque of each axis is obtained through the coaxial tension and torque model; Given that the single-axis torque of each axis is within the torque feasible region, the second objective function is minimized to obtain the single-axis torque of each axis.

7. The method according to claim 1, characterized in that, The method further includes: A tension matrix is ​​constructed using the uniaxial tension of each axis; A torque matrix is ​​constructed using the single-axis torque of each axis; A rotational speed matrix is ​​constructed using the rotational speeds of the rotors on each of the aforementioned axes; The coaxial tension and torque model is constructed using the tension matrix, the torque matrix, and the rotational speed matrix.

8. The method according to claim 7, characterized in that, Two rotors are mounted on each shaft, and the thrust matrix is ​​represented as F = [F1…Fi…Fc]. T The torque matrix is ​​represented as M = [M1…Mi…Mc]. T ; in, Xi=[ri1,ri2] T ; T is the transpose symbol, A1, A2, B1, and B2 are the preset second, third, fourth, and fifth matrices, respectively, c is the number of axes of the coaxial multirotor, Fi is the single-axis thrust of the i-th axis of the coaxial multirotor, Mi is the single-axis torque of the i-th axis of the coaxial multirotor, ri1 is the rotational speed of the first rotor on the i-th axis of the coaxial multirotor, and ri2 is the rotational speed of the second rotor on the i-th axis of the UAV.

9. A control device for a coaxial multi-rotor aircraft, characterized in that, include: The first construction module is configured to construct a first objective function based on the single-axis thrust of each axis on the coaxial multirotor aircraft and the roll moment, pitch moment and lift of the coaxial multirotor aircraft. The second construction module is configured to construct a second objective function based on the single-axis torque of each axis and the yaw moment of the fuselage; The first planning module is configured to minimize the first objective function to obtain the uniaxial tension of each axis; The second module is configured to minimize the second objective function to obtain the single-axis torque of each axis; The inverse solver module is configured to obtain the rotational speed of the rotor on each axis based on the single-axis tension and single-axis torque of each axis through a coaxial tension and torque model; The control module is configured to control the coaxial multirotor aircraft based on the rotational speed of the rotors on each of the axes.

10. An electronic device, characterized in that, include: processor; as well as Memory for storing the executable instructions of the processor; The processor is configured to execute the control method of any one of claims 1-8 by executing the executable instructions.

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