Flight parameter determination method and apparatus, aircraft and computer readable storage medium

Abstract

The application discloses a flight parameter determination method and device, an aircraft and a computer readable storage medium. The method is applied to an aircraft. The aircraft comprises N rotors and N rotor motors. The N rotors and the N rotor motors are in one-to-one correspondence. N is an integer greater than 1. The method comprises the following steps: obtaining a measured current barometric altitude of the aircraft, determining current rotating speeds of the N rotor motors, determining a current barometric altitude error according to the current rotating speeds of the N rotor motors, determining a first barometric altitude of the aircraft according to the current barometric altitude error and the current barometric altitude of the aircraft, and determining a first flight altitude and a first vertical speed of the aircraft according to the first barometric altitude. In the embodiment of the application, the measured barometric altitude is compensated by using the current barometric altitude error, so that the accuracy of the determined barometric altitude can be improved, and the accuracy of the determined flight altitude and vertical speed of the aircraft can be improved.

Description

Technical Field

[0001] This application relates to the field of aircraft technology, specifically to a method, apparatus, aircraft, and computer-readable storage medium for determining flight parameters. Background Technology

[0002] A flight vehicle is a machine capable of flying within the atmosphere or in outer space. During flight, a flight vehicle may lose the ability to receive external signals for various reasons, such as signal shielding or interference. In situations where external signals are unavailable, it is necessary to determine the flight altitude and vertical speed to ensure stable flight.

[0003] The current pressure altitude of an aircraft can be determined by measuring atmospheric static pressure, and then the aircraft's flight altitude and vertical velocity can be determined based on the current pressure altitude. However, during flight, the aircraft will disturb the surrounding airflow, causing the measured current pressure altitude of the aircraft to be inaccurate, resulting in low accuracy in the determined flight altitude and vertical velocity. Summary of the Invention

[0004] This application discloses a method, apparatus, aircraft, and computer-readable storage medium for determining flight parameters, which improves the accuracy of determining the flight altitude and vertical speed of the aircraft.

[0005] In a first aspect, embodiments of this application disclose a method for determining flight parameters. The method is applied to an aircraft, which includes N rotors and N rotor motors, where each of the N rotors corresponds one-to-one with one of the N rotor motors, and N is an integer greater than 1. The method includes:

[0006] Obtain the measured current pressure altitude of the aircraft;

[0007] Determine the current rotational speed of the N rotor motors;

[0008] Determine the current air pressure altitude error based on the current rotation speed;

[0009] The pressure altitude of the aircraft is determined based on the current pressure altitude error and the current pressure altitude, thus obtaining the first pressure altitude;

[0010] The first flight altitude and the first vertical velocity of the aircraft are determined based on the first atmospheric pressure altitude.

[0011] Secondly, embodiments of this application disclose a flight parameter determination device, which is applied to an aircraft. The aircraft includes N rotors and N rotor motors, with each of the N rotors corresponding to one of the N rotor motors, where N is an integer greater than 1. The device includes:

[0012] Acquisition unit, used to acquire the measured current air pressure altitude of the aircraft;

[0013] The first determining unit is used to determine the current rotational speed of the N rotor motors;

[0014] The second determining unit is used to determine the current air pressure altitude error based on the current rotation speed;

[0015] The third determining unit is used to determine the pressure altitude of the aircraft based on the current pressure altitude error and the current pressure altitude, and obtain the first pressure altitude;

[0016] The fourth determining unit is used to determine the first flight altitude and the first vertical velocity of the aircraft based on the first air pressure altitude.

[0017] As one possible implementation, the first determining unit is specifically used to determine the current rotational speed of the N rotor motors when the current flight state of the aircraft is horizontal flight.

[0018] As one possible implementation, the device further includes:

[0019] The fifth determining unit is used to determine the first flight altitude and the first vertical speed of the aircraft based on the current air pressure altitude when the current flight state of the aircraft is non-horizontal flight.

[0020] As one possible implementation, the fourth determining unit is specifically used for:

[0021] The first flight altitude of the aircraft is determined based on the first atmospheric pressure altitude.

[0022] Based on the first flight altitude and the second flight altitude, the first vertical velocity of the aircraft is determined, where the second flight altitude is the flight altitude of the aircraft at the previous moment.

[0023] As one possible implementation, the fourth determining unit determines the first flight altitude of the aircraft based on the first air pressure altitude, including:

[0024] If the aircraft was not flying horizontally at the previous moment, the first and second atmospheric pressure altitudes are smoothed to obtain the third atmospheric pressure altitude, where the second atmospheric pressure altitude is the atmospheric pressure altitude of the aircraft measured at the previous moment.

[0025] The first flight altitude of the aircraft is determined based on the third atmospheric pressure altitude.

[0026] As one possible implementation, the device further includes:

[0027] The calculation unit is used to perform strapdown calculations using an inertial measurement unit (IMU) based on the current air pressure altitude to obtain the third flight altitude and the second vertical velocity of the aircraft.

[0028] The sixth determining unit is used to determine the third flight altitude of the aircraft based on the first flight altitude and the third flight altitude;

[0029] The sixth determining unit is further configured to determine the third vertical velocity of the aircraft based on the first vertical velocity and the second vertical velocity.

[0030] As one possible implementation, the second determining unit is specifically used to determine the current air pressure altitude error corresponding to the current rotation speed according to a first functional relationship, wherein the first functional relationship is the functional relationship between the rotation speed of the N rotor motors and the air pressure altitude error.

[0031] As one possible implementation, the device further includes:

[0032] The seventh determining unit is used to determine the functional relationship between the rotational speed of the N rotor motors and the thrust of the aircraft, and obtain the second functional relationship;

[0033] The seventh determining unit is also used to determine the functional relationship between the pulling force and the relative speed of the aircraft in the horizontal direction relative to the airflow, and obtain the third functional relationship;

[0034] The seventh determining unit is also used to determine the functional relationship between the barometric altitude error and the relative speed to obtain a fourth functional relationship;

[0035] The seventh determining unit is further configured to determine the first functional relationship based on the second functional relationship, the third functional relationship, and the fourth functional relationship.

[0036] Thirdly, embodiments of this application disclose an aircraft including a processor and a memory, wherein the processor is used to invoke a computer program stored in the memory to execute the method disclosed in the first aspect.

[0037] Fourthly, embodiments of this application disclose a computer-readable storage medium storing a computer program or computer instructions that, when executed by a processor, implement the method disclosed in the first aspect above.

[0038] Fifthly, embodiments of this application disclose a computer program product, which includes computer program code, such that when the computer program code is run by a processor, the above-described method is executed.

[0039] In this embodiment, the aircraft acquires and measures its current atmospheric pressure altitude, determines the current rotational speeds of N rotor motors, determines the current atmospheric pressure altitude error based on the current rotational speeds of the N rotor motors, and determines the aircraft's atmospheric pressure altitude (first atmospheric pressure altitude) based on the current atmospheric pressure altitude error and the aircraft's current atmospheric pressure altitude. The first flight altitude and first vertical velocity of the aircraft are then determined based on the first atmospheric pressure altitude. It is evident that by first determining the current atmospheric pressure altitude error, then using the current atmospheric pressure altitude error to compensate for the measured atmospheric pressure altitude, and finally using the compensated atmospheric pressure altitude to determine the aircraft's flight altitude and vertical velocity, the accuracy of the determined atmospheric pressure altitude is improved, thereby improving the accuracy of the determined aircraft's flight altitude and vertical velocity. Furthermore, since the atmospheric pressure altitude error is determined based on the current rotational speeds of the rotor motors, it ensures that the atmospheric pressure altitude error corresponding to different rotor motor rotational speeds can be accurately determined, improving the accuracy of the determined atmospheric pressure altitude error and thus improving the accuracy of the determined aircraft's flight altitude and vertical velocity. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating a method for determining flight parameters disclosed in an embodiment of this application;

[0042] Figure 2 This is a flowchart illustrating another method for determining flight parameters disclosed in an embodiment of this application;

[0043] Figure 3 This is a schematic diagram of the structure of a flight parameter determination device disclosed in an embodiment of this application;

[0044] Figure 4 This is a schematic diagram of the structure of an aircraft disclosed in an embodiment of this application. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0046] This application discloses a method, apparatus, aircraft, and computer-readable storage medium for determining flight parameters, which improves the accuracy of determining the flight altitude and vertical velocity of the aircraft. These are described in detail below.

[0047] To better understand the embodiments of this application, the relevant technologies can be introduced below.

[0048] During flight, aircraft may lose signal reception due to various reasons, such as signal shielding or interference. Even without external signals, stable altitude and vertical velocity are still necessary for stable flight. In this situation, the aircraft can obtain its current altitude by measuring atmospheric static pressure using devices such as pitot tubes, and then determine its altitude and vertical velocity accordingly. However, due to variations in aircraft structure and the disturbance of surrounding airflow caused by rotors, the altitude measured by these devices is not entirely accurate, affecting the final altitude and vertical velocity results. This is particularly noticeable during high-maneuvering horizontal maneuvers, leading to significant vertical fluctuations during level flight.

[0049] To address the aforementioned problems, this application discloses a method for determining flight parameters. The method involves acquiring and measuring the current air pressure altitude of the aircraft, determining the current rotational speeds of N rotor motors, determining the current air pressure altitude error based on the current rotational speeds of the N rotor motors, determining the aircraft's air pressure altitude (first air pressure altitude) based on the current air pressure altitude error and the aircraft's current air pressure altitude, and determining the aircraft's first flight altitude and first vertical velocity based on the first air pressure altitude. It is evident that by first determining the current air pressure altitude error, then using the current air pressure altitude error to compensate for the measured air pressure altitude, and finally using the compensated air pressure altitude to determine the aircraft's flight altitude and vertical velocity, the accuracy of the determined air pressure altitude is improved due to the use of the current air pressure altitude error to compensate for the measured air pressure altitude, thereby improving the accuracy of the determined aircraft's flight altitude and vertical velocity. Furthermore, since the air pressure altitude error is determined based on the current rotational speeds of the rotor motors, it ensures that the air pressure altitude error corresponding to different rotor motor rotational speeds can be accurately determined, improving the accuracy of the determined air pressure altitude error and thus improving the accuracy of the determined aircraft's flight altitude and vertical velocity.

[0050] Please see Figure 1 , Figure 1 This is a flowchart illustrating a method for determining flight parameters disclosed in an embodiment of this application. This method can be applied to aircraft. Figure 1 As shown, determining the flight parameters may include the following steps.

[0051] 101. Obtain the current air pressure altitude of the measured aircraft.

[0052] Aircraft can use barometric altimeters to measure their current pressure altitude in real time or periodically. These barometric altimeters can be barometers, pitot tubes, altimeters, or other devices that measure the aircraft's pressure altitude.

[0053] The aircraft can obtain the measured current air pressure altitude.

[0054] In one scenario, the aircraft can periodically acquire and measure its current air pressure altitude.

[0055] In another scenario, if the aircraft can receive external signals, it can determine its altitude and vertical velocity based on those signals. Therefore, the aircraft can first determine if it can receive external signals. If it determines that it cannot receive external signals, it can periodically acquire and measure its current atmospheric pressure altitude in order to determine its altitude and vertical velocity. If it determines that it can receive external signals, step 101 can be skipped, reducing unnecessary or meaningless processing and thus conserving the aircraft's processing resources and power consumption.

[0056] The vertical velocity of an aircraft can be understood as its vertical speed, which can be either downward or upward.

[0057] 102. Determine the current speed of N rotor motors.

[0058] An aircraft may include N rotors and N rotor motors. A rotor motor is a motor used to drive the rotors. There is a one-to-one correspondence between the N rotors and the N rotor motors, meaning that each of the N rotor motors drives one of the N rotors. N is an integer greater than 1.

[0059] The aircraft can determine the current speed of N rotor motors, which means it can determine the current speed of each of the N rotor motors.

[0060] In one scenario, the aircraft can use a specialized speed measuring device to measure the current speed of N rotor motors.

[0061] In another scenario, the aircraft can first obtain the duty cycle of the drive voltage of the N rotor motors, and then determine the current rotational speed of the N rotor motors based on the duty cycle of the drive voltage of the N rotor motors.

[0062] The following are some scenarios in which an aircraft can determine the current rotational speed of its N rotor motors.

[0063] In one scenario, the aircraft can periodically determine the current rotational speed of N rotor motors.

[0064] In another scenario, if the aircraft can receive external signals, it can determine its altitude and vertical speed based on those signals. Therefore, the aircraft can first determine if it can receive external signals. If it determines that it cannot receive external signals, in order to accurately determine the aircraft's altitude and vertical speed, the current rotational speeds of N rotor motors can be periodically determined. If it determines that it can receive external signals, steps 102-105 can be skipped, reducing unnecessary or meaningless processing and thus conserving the aircraft's processing resources and reducing its power consumption.

[0065] In another scenario, when the aircraft cannot receive external signals and its flight state is not level, the rotation of the aircraft's rotors has a negligible impact on the measured pressure altitude. Therefore, the aircraft can first determine whether it can receive external signals. If it determines that it cannot receive external signals, it can then determine whether its flight state is level. If it determines that it is level, it can periodically determine the current rotational speed of N rotor motors. If it determines that it can receive external signals, or if it determines that its flight state is not level, steps 102-105 can be skipped, reducing unnecessary or meaningless processing and thus saving the aircraft's processing resources and reducing its power consumption.

[0066] In another scenario, when the aircraft is not flying horizontally, the rotation of the rotor blades has a negligible impact on the measured pressure altitude. Therefore, the aircraft can first determine whether it is flying horizontally. If it is determined to be horizontal, the current rotational speeds of the N rotor motors can be periodically determined. If it is determined to be flying horizontally, steps 102-105 can be skipped, reducing unnecessary or meaningless processing and thus conserving the aircraft's processing resources and power consumption.

[0067] The flight status of an aircraft can be determined based on the throttle position and control surface deflection angle.

[0068] Horizontal flight is flight in a horizontal direction. Non-horizontal flight can include upward flight (i.e., climbing), downward flight (i.e., descent), and hovering.

[0069] In some embodiments, when the flight state (i.e., the current flight state) of the aircraft is non-horizontal, or when it is determined that the flight state of the aircraft is non-horizontal, the influence of the rotation of the aircraft's rotor on the measured air pressure altitude is small and can be ignored. Therefore, the first flight altitude and the first vertical velocity of the aircraft can be directly determined based on the current air pressure altitude of the aircraft.

[0070] When an aircraft is climbing, gliding, or hovering, if there are no severe wind conditions, the pressure altitude directly calculated by the barometric altimeter can provide good altitude control performance. Therefore, it is reasonable to directly determine the measured pressure altitude as the aircraft's pressure altitude when the aircraft is not flying horizontally.

[0071] The aircraft can first determine its initial flight altitude based on its current air pressure altitude.

[0072] The aircraft can first obtain its previous flight status. If the aircraft was not flying horizontally in the previous moment, it can first determine the altitude corresponding to its current pressure altitude based on the correspondence between air pressure altitude and altitude. In one case, the aircraft can directly determine this altitude as its first flight altitude. In another case, the aircraft can obtain its takeoff altitude and determine the difference between this altitude and the takeoff altitude as its first flight altitude. The takeoff altitude can be understood as the altitude at which the aircraft takes off. The previous flight status can be understood as the flight status at the previous moment.

[0073] If the aircraft was in level flight at the previous moment, it can first smooth its current atmospheric pressure altitude and fourth atmospheric pressure altitude to obtain a fifth atmospheric pressure altitude. Then, it can determine its first flight altitude based on this fifth atmospheric pressure altitude. The fourth atmospheric pressure altitude is the atmospheric pressure altitude determined by the aircraft at the previous moment. The method for determining the first flight altitude based on the fifth atmospheric pressure altitude is similar to the method for determining the first flight altitude when the aircraft was not in level flight at the previous moment; a detailed description can be found above.

[0074] Because the pressure altitude may change abruptly when an aircraft switches between non-level and level flight, the determined flight altitude and vertical speed may also change abruptly. Therefore, pressure altitude smoothing can be performed first to avoid abrupt changes in flight altitude and vertical speed, i.e., sudden ascent or descent of the aircraft, making the flight of the aircraft smoother and more stable.

[0075] The smoothing method can be a weighted average method or other methods that can smooth non-continuous jump points.

[0076] After determining the first flight altitude, the aircraft can also determine its first vertical velocity based on the first and second flight altitudes. The second flight altitude is the flight altitude of the aircraft at the previous moment.

[0077] The aircraft can first calculate the difference or absolute value of the difference between the first flight altitude and the second flight altitude, and then determine the first vertical velocity of the aircraft by the ratio of the difference or absolute value of the difference to the sampling period.

[0078] When the ratio between this difference and the sampling period is determined as the first vertical velocity of the aircraft, the first vertical velocity can be positive or negative. A positive first vertical velocity indicates that the aircraft is flying downwards, and a positive first vertical velocity indicates that the aircraft is flying upwards.

[0079] The aircraft periodically determines its altitude and vertical velocity. The start time of each altitude and vertical velocity determination can be defined as the sampling time. The previous time is the most recent historical sampling time. The sampling period is the time interval between two adjacent sampling times.

[0080] As can be seen, when the aircraft's current flight state is horizontal, steps 101-105 can be used to determine if the aircraft is currently in non-horizontal flight, which improves the accuracy of the determined flight altitude and vertical velocity. When the aircraft's current flight state is non-horizontal, steps 102-104 can be omitted, and step 105 can be replaced by determining the aircraft's first flight altitude and first vertical velocity based on its current atmospheric pressure altitude. This reduces unnecessary or meaningless processing, thereby saving the aircraft's processing resources and reducing its power consumption.

[0081] Steps 101 and 102 can be executed in parallel or sequentially.

[0082] 103. Determine the current air pressure altitude error based on the current rotational speed of N rotor motors.

[0083] After determining the current rotational speeds of the N rotor motors, the aircraft can determine the current pressure altitude error based on these speeds. The aircraft can determine the current pressure altitude error corresponding to the current rotational speeds of the N rotor motors using a first functional relationship. This first functional relationship is the functional relationship between the rotational speeds of the N rotor motors and the pressure altitude error.

[0084] Uneven airflow caused by rotor rotation on an aircraft is the main reason for inaccurate barometric altitude measurement. Therefore, a first functional relationship between the rotational speed of N rotor motors and the barometric altitude error can be established in advance. This way, the corresponding barometric altitude error can be determined directly based on the rotational speed of the N rotor motors, without having to determine the above functional relationship every time. This can improve the efficiency of determining flight altitude and vertical speed.

[0085] The aircraft can determine the second functional relationship by establishing the functional relationship between the rotational speed of N rotor motors and the thrust of the aircraft. It can also determine the third functional relationship by establishing the functional relationship between the thrust of the aircraft and the relative speed of the aircraft in the horizontal direction relative to the airflow. Finally, it can determine the fourth functional relationship by establishing the functional relationship between the pressure altitude error and the relative speed of the aircraft in the horizontal direction relative to the airflow. Then, the first functional relationship mentioned above can be determined based on the second, third, and fourth functional relationships.

[0086] The aircraft can first determine or establish a functional relationship between the rotational speed of each of the N rotor motors and the thrust of the corresponding rotor. Then, based on the functional relationship between the rotational speed of each rotor motor and the thrust of the corresponding rotor, a second functional relationship can be determined or established.

[0087] For example, suppose the rotational speed of the i-th rotor motor among N rotor motors is ω. i The thrust vector generated by the i-th rotor among N rotors is F_pull i The relationship between the thrust vector generated by the i-th rotor and the rotational speed of the i-th rotor motor can be expressed as follows:

[0088]

[0089] Where ρ represents air density, S represents rotor area, r represents rotor radius, and ω i r represents the airflow velocity generated by the i-th rotor, C1 represents the lift coefficient, and i = 1, 2, ..., N.

[0090] The thrust vector generated by N rotors, that is, the overall thrust vector experienced by the aircraft during flight, or the thrust of the aircraft, can be expressed as follows:

[0091]

[0092] Based on formulas (1) and (2), the relationship between the rotational speeds of the N rotor motors and the total thrust vector of the aircraft can be determined, that is, the functional relationship between the rotational speeds of the N rotor motors and the thrust of the aircraft can be expressed as follows:

[0093]

[0094] It should be understood that the above is an exemplary description of determining or establishing a second functional relationship, and does not limit the establishment of a second functional relationship. The second functional relationship can be various variations of formula (3).

[0095] The aircraft can determine or establish a functional relationship between the aircraft's horizontal relative velocity to the airflow and the horizontal thrust. The angle between the aircraft's thrust and the horizontal direction can be determined. Then, based on the functional relationship between the aircraft's horizontal relative velocity to the airflow and the horizontal thrust, the angle, and the aircraft's thrust, a third functional relationship can be determined or established.

[0096] For example, the functional relationship between the horizontal relative velocity of the aircraft and the horizontal thrust can be expressed as follows:

[0097]

[0098] Among them, F D C represents the horizontal thrust of the aircraft. D The drag coefficient of an aircraft is related to its structure and shape. A represents the area of ​​the aircraft affected by the drag, and v represents the horizontal velocity of the aircraft relative to the airflow.

[0099] Under the control constraints of aircraft position tracking and vertical stabilization altitude maintenance, the total torque of the aircraft can be considered as zero. Accordingly, the torque equations for each direction of the aircraft in the horizontal body coordinate system O-xyz can be expressed as follows:

[0100]

[0101] Where, ∑M x The total torque along the x-axis is represented by ∑M. y The total torque along the y-axis is represented by ∑M. z G represents the total torque along the z-axis. x G represents the moment of inertia along the x-axis. y G represents the moment of inertia along the y-axis. z w represents the moment of inertia along the z-axis. x w represents the angular velocity of the aircraft along the x-axis. y w represents the angular velocity of the aircraft along the y-axis. z γ represents the angular velocity of the aircraft along the z-axis. x γ represents the angular acceleration of the aircraft along the x-axis. y γ represents the angular acceleration of the aircraft along the y-axis. z This represents the angular acceleration of the aircraft along the z-axis. Let G represent the rate of change of G, i.e., the derivative of G with respect to time.

[0102] Since the lift generated by the fuselage of an aircraft with rotors is much smaller than the lift provided by rotor rotation, the lift generated by the fuselage can be ignored. Based on this, simplifying the above formula (5) yields the dynamic equations for lateral and longitudinal motion, which can be expressed as follows:

[0103]

[0104] Among them, F_pull x F_pull represents the pull force generated along the x-axis by the rotor rotation. y F_pull represents the pulling force generated by the rotor rotation along the y-axis. z F_resist represents the thrust generated along the z-axis by the rotor rotation. x F_resist represents the drag force experienced by the aircraft along the x-axis. y F_pull represents the drag force experienced by the aircraft along the y-axis. z a represents the drag force experienced by the aircraft along the z-axis. x a represents the acceleration of the aircraft along the x-axis. y This represents the acceleration of the aircraft along the y-axis, where m represents the mass of the aircraft, and g represents the acceleration due to gravity, typically 9.8 m / s². 2 .

[0105] Equation (6) shows that the horizontal component of the thrust, in addition to counteracting the drag, also generates horizontal acceleration, causing the aircraft to move in the horizontal direction. The thrust, drag, and horizontal acceleration can be expressed as follows:

[0106] F_pull*sinθ=ma―F_resist (7)

[0107] Where θ represents the angle between F_pull and the horizontal direction (i.e., the plane containing the x and y axes), and F_resist represents the drag experienced by the aircraft in the horizontal direction.

[0108] According to formulas (4) and (7), the functional relationship between the thrust of the aircraft and the relative speed of the aircraft in the horizontal direction relative to the airflow can be determined. This functional relationship can be expressed as follows:

[0109]

[0110] Formula (8) is derived under the assumption that the aircraft is flying horizontally and in a straight line, ignoring the influence of other factors such as battery energy and thrust-to-weight ratio. It should be noted that in actual situations, other nonlinear factors may affect this relationship. Therefore, the above is an exemplary explanation of determining or establishing the third functional relationship, and does not limit the establishment of the third functional relationship. The third functional relationship can be various variations of formula (8).

[0111] The dynamic pressure generated by the relative motion of the aircraft with the air is the reason for the inaccuracy of the barometric altitude measurement device. Due to the airflow interference generated by the rotor rotation, it is impossible to accurately determine the relationship between the barometric altitude error and the relative velocity of the aircraft in the horizontal direction relative to the airflow. For example, the functional relationship between the barometric altitude error and the relative velocity of the aircraft in the horizontal direction relative to the airflow can be expressed as follows:

[0112]

[0113] Here, Δh represents the pressure altitude error caused by the relative velocity between the aircraft and the air.

[0114] For example, the theoretical relationship between the rotational speed of N rotor motors and the relative speed of the aircraft in the horizontal direction relative to the airflow can be derived from formulas (3) and (8). However, as explained below formula (8), the influence of other factors cannot be ruled out. Therefore, to determine the absolute relationship between the rotational speed of the rotor motors and the relative speed, it is necessary to calibrate the relative speed between the aircraft and the air. Therefore, the relationship function between the rotational speed of N rotor motors and the air pressure altitude error can be determined first according to formulas (3), (8) and (9). That is, the relationship function between the rotational speed of N rotor motors and the air pressure altitude error can be established by combining formulas (3), (8) and (9). Then, the unknown parameters in the relationship function can be fitted by wind tunnel test, so as to obtain the first functional relationship.

[0115] Wind tunnel tests were conducted on the aircraft to be calibrated, assuming the maximum level flight speed of the aircraft is v. max , in [0, v max Within a given interval, a velocity gradient of magnitude {v1, v2, ..., v} is set at constant velocity intervals. max Based on the set of velocity gradients, wind speeds are set, and hovering tests are conducted on the aircraft. Then, for each wind speed condition, the pressure altitude (h_baro) calculated by the aircraft's pressure-altitude measurement device and the actual pressure altitude (h_real) for hovering are recorded, resulting in {(h_baro1, h_real1), (h_baro2, h_real2), ..., (h_baro...}. max h_real max)}, and the rotational speed of each rotor motor at each wind speed {(ω 11 ,ω 21 ,...,ω N1 ),(ω 12 ,ω 22 ,...ω N2 ),...,(ω 1max ,ω 2max ,...ω Nmax A one-to-one correspondence. Barometric altitude error, i.e., barometric altitude measurement error, can be expressed as follows:

[0116] Δh=h_baro-h_real (10)

[0117] By substituting each wind speed and its corresponding Δh into the relationship function between the rotational speed of N rotor motors and the pressure altitude error, the unknown parameters in the relationship function can be determined, thus obtaining the first functional relationship.

[0118] 104. Determine the aircraft's pressure altitude based on the current pressure altitude error and the measured current pressure altitude to obtain the first pressure altitude.

[0119] After determining the current pressure altitude error, the aircraft can determine its first pressure altitude based on the current pressure altitude error and the measured current pressure altitude. In other words, the measured current pressure altitude can be compensated for by using the current pressure altitude error to obtain the first pressure altitude. The aircraft can determine the first pressure altitude by summing the current pressure altitude error and the measured current pressure altitude.

[0120] 105. Determine the first flight altitude and first vertical velocity of the aircraft based on the first atmospheric pressure altitude.

[0121] After the aircraft obtains its first atmospheric pressure altitude, its first flight altitude and first vertical velocity can be determined based on this altitude.

[0122] The aircraft can first determine its first flight altitude based on the first atmospheric pressure altitude, that is, the aircraft's current flight altitude can be determined based on the first atmospheric pressure altitude.

[0123] The aircraft can first obtain its previous flight status. If the aircraft was in level flight in the previous moment, it can first determine the altitude corresponding to the first pressure altitude based on the correspondence between air pressure altitude and altitude. In one case, the aircraft can directly determine this altitude as its first flight altitude. In another case, the aircraft can obtain its takeoff altitude and determine the difference between this altitude and the takeoff altitude as its first flight altitude.

[0124] If the aircraft was not flying horizontally at the previous moment, it can first smooth the first and second atmospheric pressure altitudes to obtain a third atmospheric pressure altitude. Then, the aircraft's first flight altitude can be determined based on this third atmospheric pressure altitude. The second atmospheric pressure altitude is the altitude measured by the aircraft at the previous moment. The method of determining the aircraft's first flight altitude based on the third atmospheric pressure altitude is similar to the method used when the aircraft was flying horizontally at the previous moment; a detailed description can be found above.

[0125] Because the pressure altitude may change abruptly when an aircraft switches between level flight and non-level flight, the determined flight altitude and vertical speed may also change abruptly. Therefore, pressure altitude smoothing can be performed first to avoid abrupt changes in flight altitude and vertical speed, i.e., sudden ascent or descent of the aircraft, making the flight of the aircraft smoother and more stable.

[0126] After determining the first flight altitude, the aircraft can also determine its first vertical velocity based on the first and second flight altitudes. The second flight altitude is the flight altitude of the aircraft at the previous moment. For a detailed description, please refer to the relevant description below step 102.

[0127] In some embodiments, the aircraft can use an inertial measurement unit (IMU) to perform strapdown calculations based on the measured current air pressure altitude to obtain the aircraft's third flight altitude and second vertical velocity. The aircraft can determine its fourth flight altitude based on the first and third flight altitudes, and its third vertical velocity based on the first and second vertical velocities.

[0128] The aircraft can use an IMU (Installation Unit) to perform strapdown calculations based on the measured current air pressure altitude to obtain its third altitude and second vertical velocity. Therefore, the aircraft can determine not only its first altitude and first vertical velocity using the methods described above, but also its third altitude and second vertical velocity using IMU calculations. To improve the stability and accuracy of the final determined altitude and vertical velocity, the final altitude and vertical velocity can be determined based on these two methods. The aircraft can determine its fourth altitude (final altitude) based on its first and third altitudes by filtering and updating the first and third altitudes. Similarly, the aircraft can determine its third vertical velocity (final vertical velocity) based on its first and second vertical velocities by filtering and updating the first and second vertical velocities. The filtering and updating method can be Kalman filtering or other equivalent filtering and updating methods.

[0129] Once the aircraft has determined its altitude and vertical speed, it can fly according to those parameters. The aircraft can reach the determined altitude by maintaining the determined vertical speed.

[0130] exist Figure 1 In the described method for determining flight parameters, the aircraft acquires and measures its current atmospheric pressure altitude, determines the current rotational speeds of N rotor motors, determines the current atmospheric pressure altitude error based on the current rotational speeds of the N rotor motors, and determines the aircraft's atmospheric pressure altitude (first atmospheric pressure altitude) based on the current atmospheric pressure altitude error and the aircraft's current atmospheric pressure altitude. The first flight altitude and first vertical velocity of the aircraft are then determined based on the first atmospheric pressure altitude. It is evident that by first determining the current atmospheric pressure altitude error, then using the current atmospheric pressure altitude error to compensate for the measured atmospheric pressure altitude, and finally using the compensated atmospheric pressure altitude to determine the aircraft's flight altitude and vertical velocity, the accuracy of the determined atmospheric pressure altitude is improved due to the use of the current atmospheric pressure altitude error to compensate for the measured atmospheric pressure altitude, thereby improving the accuracy of the determined aircraft's flight altitude and vertical velocity. Furthermore, since the atmospheric pressure altitude error is determined based on the current rotational speeds of the rotor motors, it ensures that the atmospheric pressure altitude error corresponding to different rotor motor rotational speeds can be accurately determined, further improving the accuracy of the determined atmospheric pressure altitude error and thus improving the accuracy of the determined aircraft's flight altitude and vertical velocity.

[0131] Please see Figure 2 , Figure 2 This is a schematic flowchart of another flight parameter determination method disclosed in an embodiment of this application. The flight parameter determination method can be applied to aircraft. Figure 2 As shown, determining the flight parameters may include the following steps.

[0132] 201. Obtain the current air pressure altitude of the measured aircraft.

[0133] For a detailed description of step 201, please refer to step 101.

[0134] 202. Determine whether the current flight state of the aircraft is horizontal. If the current flight state of the aircraft is horizontal, proceed to step 203. If the current flight state of the aircraft is not horizontal, proceed to step 207.

[0135] Steps 201 and 202 can be executed in parallel or sequentially.

[0136] 203. Determine the current speed of N rotor motors.

[0137] For a detailed description of step 203, please refer to step 102.

[0138] 204. Determine the current air pressure altitude error based on the current rotational speed of N rotor motors.

[0139] For a detailed description of step 204, please refer to step 103.

[0140] 205. Determine the first pressure altitude of the aircraft based on the current pressure altitude error and the measured current pressure altitude.

[0141] For a detailed description of step 205, please refer to step 104.

[0142] 206. Determine the first flight altitude and first vertical velocity of the aircraft based on the first atmospheric pressure altitude.

[0143] For a detailed description of step 206, please refer to step 105.

[0144] 207. Determine the first flight altitude and first vertical velocity of the aircraft based on the current air pressure altitude.

[0145] For a detailed description of step 207, please refer to the relevant description below step 102.

[0146] 208. Based on the measured current air pressure altitude, use the IMU to perform strapdown calculations to obtain the aircraft's third flight altitude and second vertical velocity.

[0147] 209. Determine the fourth flight altitude of the aircraft based on the first and third flight altitudes, and determine the third vertical velocity of the aircraft based on the first and second vertical velocities.

[0148] For a detailed description of steps 208-209, please refer to the relevant description below step 105.

[0149] It should be understood that some of the above steps may be omitted. For example, steps 208 and 209 may be omitted. For example, steps 202 and 207 may be omitted.

[0150] exist Figure 2 In the described method for determining flight parameters, the aircraft acquires and measures its current pressure altitude. When the aircraft is in level flight, the current rotational speeds of N rotor motors are determined. The current pressure altitude error is determined based on the current rotational speeds of the N rotor motors. The aircraft's pressure altitude is then determined using the current pressure altitude error and the current pressure altitude to obtain a first pressure altitude. The first flight altitude and first vertical velocity are then determined based on this first pressure altitude. When the aircraft is not in level flight, the first flight altitude and first vertical velocity are determined based on the current pressure altitude. Using an IMU (Integrated Measurement Unit), a strapdown calculation is performed based on the measured current pressure altitude to obtain the aircraft's third flight altitude and second vertical velocity. The fourth flight altitude is determined based on the first and third flight altitudes, and the third vertical velocity is determined based on the first and second vertical velocities. It is evident that determining the aircraft's final altitude and vertical velocity using both IMU-determined altitude and vertical velocity, along with other methods, improves the accuracy and stability of the determined altitude and vertical velocity. Furthermore, when the aircraft is in level flight, compensation for the measured altitude error using the current barometric altitude improves the accuracy of the determined altitude, thus enhancing the accuracy of the determined altitude and vertical velocity. Moreover, since the altitude error is based on the rotor motor's current speed, the accuracy of the determined altitude error corresponding to different rotor motor speeds is improved, further enhancing the accuracy of the determined altitude and vertical velocity. Finally, when the aircraft is not in level flight, the initial altitude and vertical velocity can be directly determined from the current altitude, reducing unnecessary or meaningless processing, thus conserving processing resources and reducing power consumption.

[0151] It should be understood that the same or corresponding information in the different embodiments above can be referenced to each other.

[0152] Please see Figure 3 , Figure 3This is a schematic diagram of a flight parameter determination device disclosed in an embodiment of this application. The flying car includes an aircraft and other components, which are separable and combinable. The flight parameter determination device is applied to the aircraft, which may include N rotors and N rotor motors, with each of the N rotors corresponding to one of the N rotor motors, where N is an integer greater than 1. Figure 3 As shown, the flight parameter determination device may include:

[0153] Acquisition unit 301 is used to acquire the current air pressure altitude of the measured aircraft;

[0154] The first determining unit 302 is used to determine the current rotational speed of N rotor motors;

[0155] The second determining unit 303 is used to determine the current air pressure altitude error based on the current rotation speed of the N rotor motors;

[0156] The third determining unit 304 is used to determine the pressure altitude of the aircraft based on the current pressure altitude error and the measured current pressure altitude, and obtain the first pressure altitude;

[0157] The fourth determining unit 305 is used to determine the first flight altitude and the first vertical velocity of the aircraft based on the first air pressure altitude.

[0158] In some embodiments, the first determining unit 302 is specifically used to determine the current rotational speed of N rotor motors when the current flight state of the aircraft is horizontal flight.

[0159] In some embodiments, the flight parameter determining device may further include:

[0160] The fifth determining unit 306 is used to determine the first flight altitude and the first vertical speed of the aircraft based on the measured current air pressure altitude when the current flight state of the aircraft is non-horizontal flight.

[0161] In some embodiments, the fourth determining unit 305 is specifically used for:

[0162] The first flight altitude of the aircraft is determined based on the first atmospheric pressure altitude.

[0163] Based on the first flight altitude and the second flight altitude, the first vertical velocity of the aircraft is determined, and the second flight altitude is the flight altitude of the aircraft at the previous moment.

[0164] In some embodiments, the fourth determining unit 305 determines the first flight altitude of the aircraft based on the first air pressure altitude, including:

[0165] If the aircraft was not flying horizontally in the previous moment, the first and second atmospheric pressure altitudes are smoothed to obtain the third atmospheric pressure altitude. The second atmospheric pressure altitude is the atmospheric pressure altitude of the aircraft measured in the previous moment.

[0166] The first flight altitude of the aircraft is determined based on the third atmospheric pressure altitude.

[0167] In some embodiments, the flight parameter determining device may further include:

[0168] The calculation unit 307 is used to perform strapdown calculations using an IMU based on the measured current air pressure altitude to obtain the aircraft's third flight altitude and second vertical velocity;

[0169] The sixth determining unit 308 is used to determine the third flight altitude of the aircraft based on the first flight altitude and the third flight altitude;

[0170] The sixth determining unit 308 is also used to determine the third vertical velocity of the aircraft based on the first vertical velocity and the second vertical velocity.

[0171] In some embodiments, the second determining unit 303 is specifically used to determine the current air pressure altitude error corresponding to the current rotation speed of the N rotor motors according to a first functional relationship, wherein the first functional relationship is the functional relationship between the rotation speed of the N rotor motors and the air pressure altitude error.

[0172] In some embodiments, the flight parameter determining device may further include:

[0173] The seventh determining unit 309 is used to determine the functional relationship between the rotational speed of N rotor motors and the thrust of the aircraft, and obtain the second functional relationship;

[0174] The seventh determining unit 309 is also used to determine the functional relationship between the aircraft's thrust and the aircraft's relative speed in the horizontal direction relative to the airflow, thus obtaining the third functional relationship;

[0175] The seventh determining unit 309 is also used to determine the functional relationship between the barometric altitude error and the relative velocity, thus obtaining the fourth functional relationship;

[0176] The seventh determining unit 309 is also used to determine the first functional relationship based on the second functional relationship, the third functional relationship, and the fourth functional relationship.

[0177] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the flight parameter determining device, acquisition unit 301, first determining unit 302, second determining unit 303, third determining unit 304, fourth determining unit 305, fifth determining unit 306, calculation unit 307, sixth determining unit 308, and seventh determining unit 309 described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0178] In the several embodiments provided in this application, the coupling between the units can be electrical, mechanical or other forms of coupling.

[0179] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0180] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of an aircraft disclosed in an embodiment of this application. Figure 4 As shown, the aircraft may include a processor 401 and a memory 402. The memory 402 may store one or more computer programs. The one or more computer programs are configured to perform the methods described in the foregoing method embodiments. The memory 402 may be independent or integrated with the processor 401.

[0181] Processor 401 may include one or more processing cores. Processor 401 can connect to various parts of the aircraft using various interfaces and lines. It can perform various functions and process data by running or executing instructions, programs, code sets, or instruction sets stored in memory 402, and by calling data stored in memory 402. Optionally, processor 401 may be implemented using at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), or programmable logic array (PLA). Processor 401 may integrate one or a combination of central processing unit (CPU), graphics processing unit (GPU), and modem. The CPU mainly handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem is used for wireless communication. It is understood that the modem may also not be integrated into processor 401 and may be implemented separately through a communication chip.

[0182] The memory 402 may include random access memory (RAM) or read-only memory (ROM). The memory 402 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 402 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as touch functionality, sound playback functionality, image playback functionality, etc.), and instructions for implementing the various method embodiments described above. The data storage area may also store data created during the use of the aircraft (such as phone books, audio and video data, chat log data, etc.).

[0183] When the computer program instructions stored in memory 402 are executed, the processor 401 can be used to perform various operations performed by the aircraft in the above method embodiments. Specific implementations of these operations can be found in the preceding embodiments and will not be repeated here.

[0184] This application discloses a schematic diagram of a computer-readable storage medium. The computer-readable medium stores computer program code, which can be called by a processor to execute various operations described in the above method embodiments. Specific implementations of each of these operations can be found in the preceding embodiments and will not be repeated here.

[0185] Computer-readable storage media can be electronic storage devices such as flash memory, electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), hard disk, or ROM. Optionally, computer-readable storage media can include non-transitory computer-readable storage medium. The computer-readable storage medium has storage space for program code that performs any of the method steps described above. This computer program code can be read from or written to one or more computer program products. The computer program code can be compressed, for example, in a suitable form.

[0186] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for determining flight parameters, characterized in that, The method is applied to an aircraft, which includes N rotors and N rotor motors, wherein the N rotors correspond one-to-one with the N rotor motors, and N is an integer greater than 1. The method includes: Obtain the measured current pressure altitude of the aircraft; If it is determined that the aircraft cannot receive external signals and the current flight state of the aircraft is horizontal flight, determine the current rotation speed of the N rotor motors; The current pressure altitude error corresponding to the current rotational speed is determined based on a first functional relationship, which is the functional relationship between the rotational speeds of the N rotor motors and the pressure altitude error. The process of determining the first functional relationship includes: determining the functional relationship between the rotational speeds of the N rotor motors and the thrust of the aircraft to obtain a second functional relationship; determining the functional relationship between the thrust and the relative speed of the aircraft in the horizontal direction relative to the airflow to obtain a third functional relationship; determining the functional relationship between the pressure altitude error and the relative speed to obtain a fourth functional relationship; and determining the first functional relationship based on the second, third, and fourth functional relationships. The pressure altitude of the aircraft is determined based on the current pressure altitude error and the current pressure altitude, thus obtaining the first pressure altitude; The first flight altitude and the first vertical velocity of the aircraft are determined based on the first air pressure altitude.

2. The method according to claim 1, characterized in that, The method further includes: When the current flight state of the aircraft is non-horizontal flight, the first flight altitude and the first vertical speed of the aircraft are determined based on the current air pressure altitude.

3. The method according to claim 1, characterized in that, The step of determining the first flight altitude and first vertical velocity of the aircraft based on the first air pressure altitude includes: The first flight altitude of the aircraft is determined based on the first atmospheric pressure altitude. Based on the first flight altitude and the second flight altitude, the first vertical velocity of the aircraft is determined, where the second flight altitude is the flight altitude of the aircraft at the previous moment.

4. The method according to claim 3, characterized in that, Determining the first flight altitude of the aircraft based on the first atmospheric pressure altitude includes: If the aircraft was not flying horizontally at the previous moment, the first and second atmospheric pressure altitudes are smoothed to obtain the third atmospheric pressure altitude, where the second atmospheric pressure altitude is the atmospheric pressure altitude of the aircraft measured at the previous moment. The first flight altitude of the aircraft is determined based on the third atmospheric pressure altitude.

5. The method according to any one of claims 1-4, characterized in that, The method further includes: Based on the current air pressure altitude, the third flight altitude and the second vertical velocity of the aircraft are obtained by using a strapdown calculation with an inertial measurement unit (IMU). The fourth flight altitude of the aircraft is determined based on the first flight altitude and the third flight altitude; The third vertical velocity of the aircraft is determined based on the first vertical velocity and the second vertical velocity.

6. A flight parameter determining device, characterized in that, The device is applied to an aircraft, which includes N rotors and N rotor motors, wherein the N rotors correspond one-to-one with the N rotor motors, and N is an integer greater than 1. The device includes: Acquisition unit, used to acquire the measured current air pressure altitude of the aircraft; The first determining unit is used to determine the current rotational speed of the N rotor motors when it is determined that the aircraft cannot receive external signals and the current flight state of the aircraft is horizontal flight. The second determining unit is used to determine the current pressure altitude error corresponding to the current rotational speed based on a first functional relationship, wherein the first functional relationship is a functional relationship between the rotational speeds of the N rotor motors and the pressure altitude error; the process of determining the first functional relationship includes: determining a functional relationship between the rotational speeds of the N rotor motors and the thrust of the aircraft to obtain a second functional relationship; determining a functional relationship between the thrust and the relative speed of the aircraft in the horizontal direction relative to the airflow to obtain a third functional relationship; determining a functional relationship between the pressure altitude error and the relative speed to obtain a fourth functional relationship; and determining the first functional relationship based on the second functional relationship, the third functional relationship, and the fourth functional relationship. The third determining unit is used to determine the pressure altitude of the aircraft based on the current pressure altitude error and the current pressure altitude, and obtain the first pressure altitude; The fourth determining unit is used to determine the first flight altitude and the first vertical velocity of the aircraft based on the first air pressure altitude.

7. An aircraft, characterized in that, It includes a processor and a memory, the processor being used to invoke a computer program stored in the memory to implement the method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or computer instructions that, when executed by a processor, implement the method as described in any one of claims 1-5.

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