An aircraft-based object projection method, apparatus, program product, and storage medium

Abstract

Embodiments of the present application provide a kind of based on aircraft's method, equipment, program product and storage medium of throwing article, aircraft is hung and is to be thrown article;The method comprises: obtaining the flight parameters and environmental parameters of aircraft, and the target landing point and the launch trajectory model of to-be-launched article;The predicted landing point when to-be-launched article is launched at different launch time is determined based on launch trajectory model, and target hit probability is calculated according to the gap between predicted landing point and target landing point and determines target launch time;According to flight parameters, environmental parameters, launch trajectory model and target landing point, the target launch point of to-be-launched article is determined;When target hit probability is greater than probability threshold or reaches target launch time, control aircraft to launch to-be-launched article at target launch point.By determining the target hit probability corresponding to different launch time, target launch time and the target launch point of to-be-launched article, the ability of aircraft autonomous planning launch is given.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft technology, in particular to a method, device, program product and storage medium for throwing objects based on an aircraft. BACKGROUND

[0002] With the rapid development of science and technology, various aircrafts including unmanned aerial vehicles have been widely used in various fields. Aircrafts provide new solutions for the execution of many tasks due to their flexibility, maneuverability and the advantage of operating in dangerous environments. In the specific application scenarios of throwing materials such as rescue supplies and fire extinguishing bullets, the involvement of aircrafts is gradually changing the traditional operation mode and showing great potential. In the related art, the throwing of materials by aircrafts still depends on human control. How to enable aircrafts to have the ability of autonomous planning of material throwing is a technical problem to be solved in the field. SUMMARY

[0003] The purpose of the embodiments of the present application is to provide a method, device, program product and storage medium for throwing objects based on an aircraft, so as to realize the technical effect of autonomous planning of material throwing by the aircraft.

[0004] The first aspect of the embodiments of the present application provides a method for throwing objects based on an aircraft, wherein the aircraft is mounted with a to-be-thrown object; the method comprises:

[0005] obtaining flight parameters and environmental parameters of the aircraft, and a throwing trajectory model and a target landing point of the to-be-thrown object;

[0006] determining a predicted landing point when the to-be-thrown object is thrown at different throwing times based on the throwing trajectory model, and calculating a target hitting probability and determining a target throwing time according to the difference between the predicted landing point and the target landing point;

[0007] determining a target throwing point of the to-be-thrown object according to the flight parameters, the environmental parameters, the throwing trajectory model and the target landing point;

[0008] when the target hitting probability is greater than a probability threshold or the target throwing time is reached, controlling the aircraft to throw the to-be-thrown object at the target throwing point.

[0009] In the implementation process, the predicted drop point of the object to be dropped at different dropping times is predicted by using a dropping trajectory model, so as to determine the target hit probability corresponding to different dropping times and determine the target dropping time, so that the aircraft can autonomously plan to drop the object to be dropped at an appropriate time (the target hit probability is greater than a threshold or the target dropping time is reached). In addition, the target dropping point of the object to be dropped is determined by using the flight parameters, the environmental parameters and the dropping trajectory model, so that the aircraft can autonomously plan to drop the object to be dropped at a suitable position, thereby endowing the aircraft with the ability of autonomous planning of dropping.

[0010] Further, the target hit probability is calculated according to the difference between the predicted drop point and the target drop point, including:

[0011] The basic hit probability is calculated according to the difference between the predicted drop point and the target drop point.

[0012] The basic hit probability is corrected based on a disturbance index affecting the attitude stability of the aircraft and a corresponding disturbance threshold to obtain the target hit probability, wherein the disturbance index includes a horizontal disturbance angular velocity, a vertical velocity and a wind speed change rate of the aircraft.

[0013] In the implementation process, the basic hit probability is corrected by using the disturbance index which will interfere with the attitude stability of the aircraft, so that the unstable factors caused by the shaking of the aircraft itself and the change of wind speed are considered when the target hit probability is predicted, thereby improving the prediction accuracy of the target hit probability and the prediction accuracy of the dropping time.

[0014] Further, the target dropping time is determined by the following steps:

[0015] A candidate dropping time is determined, and a predicted drop point when the object to be dropped is dropped at the candidate dropping time is determined based on the dropping trajectory model.

[0016] The next candidate dropping time is determined based on the difference between the predicted drop point and the target drop point, and the step of determining the predicted drop point when the object to be dropped is dropped at the candidate dropping time by using the dropping trajectory model is returned until the predicted drop point and the target drop point are the same, and the candidate dropping time of the current iteration is determined as the target dropping time.

[0017] In the implementation process, the optimal target dropping time is solved from the highly nonlinear dropping trajectory model by using a numerical optimization method, so that the aircraft has the ability of autonomous planning of dropping time.

[0018] Further, the target dropping point of the object to be dropped is determined according to the flight parameters, the environmental parameters, the dropping trajectory model and the target drop point, including:

[0019] determining an ideal drop point of the object to be dropped according to the flight parameter, the environment parameter, the drop trajectory model and the target drop point;

[0020] estimating a wind deviation and an inertia deviation based on the flight parameter and the environment parameter; wherein the wind deviation is used to represent the deviation of the wind speed to the drop trajectory of the object to be dropped; and the inertia deviation is used to represent the deviation of the movement of the aircraft to the drop trajectory of the object to be dropped;

[0021] correcting the ideal drop point by using the wind deviation and the inertia deviation to obtain the target drop point.

[0022] In the above implementation process, the flight speed of the aircraft when dropping the object to be dropped and the deviation influence of the wind speed to the drop trajectory are considered, and then the estimated wind deviation and inertia deviation are used to correct the ideal drop point, thereby improving the prediction accuracy of the target drop point.

[0023] Further, in the flight process and the object dropping process of the aircraft, the method further comprises:

[0024] parsing the vertical thrust component of the aircraft from the throttle command of the aircraft;

[0025] estimating the current vertical disturbance of the aircraft by using the current vertical speed observation value and the historical vertical speed estimation value of the aircraft through the first extended state observer (ESO);

[0026] estimating the current vertical speed estimation value of the aircraft by using the estimated historical vertical disturbance and the vertical thrust component through the first ESO;

[0027] estimating the mass of the aircraft based on the force in the vertical direction of the aircraft to obtain the current estimated mass; wherein in the unbalanced state, the force in the vertical direction includes the vertical thrust, the gravity and the vertical disturbance; and in the balanced state, the force in the vertical direction includes the vertical thrust and the gravity;

[0028] controlling the speed of the aircraft based on the current vertical speed estimation value and the current estimated mass.

[0029] In the above implementation process, the estimation of the vertical speed by the first ESO avoids the influence of the fluctuation of the sensor on the stable control of the speed of the aircraft, and the vertical disturbance estimated by the first ESO is used to further estimate the overall mass of the aircraft, thereby providing real-time feedback for the throttle controller, so that the throttle controller can automatically match the actual mounting state of the aircraft, achieving the purpose of disturbance rejection and self-adaptation. In addition, the part of the vertical thrust component that is output more to compensate for the disturbance is identified in this embodiment, so as to compensate for the disturbance caused by the additional gravity or air resistance of the object to be dropped.

[0030] Further, during the flight and the object-throwing process of the aircraft, the method further comprises:

[0031] estimating the current angular velocity change rate of the aircraft by the second extended state observer using the target moment of inertia of the aircraft, the estimated historical disturbance torque, and the current flight torque;

[0032] estimating the current disturbance torque generated by the object to be thrown on the aircraft by the second extended state observer using the current angular velocity observation value and the historical angular velocity estimation value;

[0033] controlling the attitude of the aircraft based on the current angular velocity change rate.

[0034] In the above implementation process, the estimated current disturbance torque is fed back to the attitude controller, so that the control instruction containing the compensation for the current disturbance torque is output by the attitude controller, thereby realizing the active compensation of the external input of the system. When there is an unstructured disturbance, i.e., weight change, the control instruction can be corrected in real time to ensure the stability of the attitude.

[0035] Further, the method further comprises:

[0036] determining the compensation moment of inertia of the object to be thrown currently mounted on the aircraft relative to the aircraft;

[0037] obtaining the body moment of inertia of the aircraft;

[0038] determining the target moment of inertia based on the body moment of inertia and the compensation moment of inertia.

[0039] In the above implementation process, the moment of inertia of the aircraft body is corrected based on the influence of the object to be thrown currently mounted on the aircraft on the moment of inertia of the aircraft, thereby improving the estimation accuracy of the angular velocity.

[0040] The second aspect of the embodiment of the application provides a computer program product, the computer program product comprising a computer program, the computer program being executed by a processor to implement the method of any of the first aspect.

[0041] The third aspect of the embodiment of the application provides an object-throwing control device, the device comprising:

[0042] a processor;

[0043] a memory for storing processor-executable instructions;

[0044] When the processor invokes the executable instructions, the operations of the method of any of the first aspect are implemented.

[0045] The fourth aspect of the embodiments of the present application provides a computer readable storage medium, which stores computer instructions, and the computer instructions are executed by a processor to implement the steps of the method in any of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0047] Figure 1 A flowchart of a method for throwing objects based on an aircraft provided by the embodiments of the present application is shown in FIG. 1.

[0048] Figure 2 A flowchart of another method for throwing objects based on an aircraft provided by the embodiments of the present application is shown in FIG. 2.

[0049] Figure 3 A flowchart of another method for throwing objects based on an aircraft provided by the embodiments of the present application is shown in FIG. 3.

[0050] Figure 4 A flowchart of another method for throwing objects based on an aircraft provided by the embodiments of the present application is shown in FIG. 4.

[0051] Figure 5 A hardware structure diagram of a device for controlling throwing objects provided by the embodiments of the present application is shown in FIG. 5. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application.

[0053] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of the present application, the terms “first”, “second”, etc. are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0054] An aircraft refers to a device with a flight function, including but not limited to unmanned aerial vehicles (UAVs), unmanned aerial vehicles, manned aerial vehicles, flying cars, civil aviation aircraft, and various types of air transportation tools.

[0055] The material dropping capability of the aircraft can be applied in various scenarios, for example, in a rescue scenario, if the vehicle cannot enter the disaster area in time due to road congestion, the aircraft can be used to drop supplies for quick distribution of rescue supplies. For example, in a high-rise building fire or a closed space disaster, traditional firefighting methods are difficult to quickly access the target. At this time, the aircraft can be used to drop window breaking bullets to break the window and then drop fire extinguishing bullets to extinguish the fire.

[0056] However, in the related art, the material dropping of the aircraft depends on human operation. However, due to the limited field of view of the operator, it is difficult to perform accurate material dropping through human operation. Especially in a fire fighting scenario, it is more necessary for the aircraft to accurately throw window breaking bullets and fire extinguishing bullets to the target position. Therefore, if the aircraft has the capability of autonomous planning of material dropping, the accuracy of material dropping can be greatly improved. Autonomous planning of material dropping of the aircraft needs to consider the timing of dropping and the target of dropping, that is, dropping the material at the right time window at the right dropping position to the correct dropping target.

[0057] Therefore, the present application provides a method for dropping material based on an aircraft, which is used to realize the autonomous planning of the aircraft in the process of dropping material. The method can be executed by the aircraft or by a control terminal in communication connection with the aircraft. The aircraft is mounted with the material to be dropped. The material to be dropped refers to the material to be dropped, which can be different specific materials in different application scenarios. For example, in an emergency rescue scenario, the material to be dropped can be rescue supplies; in a fire fighting scenario, the material to be dropped can be window breaking bullets and fire extinguishing bullets, etc. The present application does not limit the specific variety of the material to be dropped. Referring to Figure 1 The present application provides a method for dropping material based on an aircraft, which includes steps 110-140. In this embodiment, the execution order of steps 120 and 130 is not limited, and the two steps can be executed simultaneously.

[0058] Step 110: Obtain the flight parameters and environmental parameters of the aircraft, and the dropping trajectory model and target landing point of the material to be dropped.

[0059] The flight parameters include various parameters related to the aerial vehicle during the aerial operation. The flight parameters can include flight parameters at the current time and flight parameters at a future time. The flight parameters at the current time can be sensed by sensors carried by the aerial vehicle, and the flight parameters at the future time can be determined according to a flight plan. Since the flight parameters are used in the subsequent steps to determine the target drop point of the object to be dropped in combination with the environmental parameters, the drop trajectory model and the target drop point, when the environmental parameters, the drop trajectory model and the target drop point are unchanged, the aerial vehicle needs to drop the object to be dropped at different drop positions due to different altitudes of the aerial vehicle or different attitudes of the aerial vehicle. Therefore, the flight parameters at least include the altitude of the aerial vehicle and the attitude of the aerial vehicle. The attitude of the aerial vehicle at least includes the pitch angle of the aerial vehicle, and can further include the roll angle and / or the yaw angle.

[0060] The environmental parameters refer to parameters used to characterize the surrounding environment in the airspace where the aerial vehicle is located. The environmental parameters can include environmental parameters at the current time and environmental parameters at a future time. The environmental parameters at the current time can be sensed by environmental sensors carried by the aerial vehicle or obtained through other prior information related to the environment. The environmental parameters at the future time can be determined through predicted environmental information obtained through other channels. Since the environmental parameters are used in the subsequent steps to determine the target drop point of the object to be dropped in combination with the flight parameters, the drop trajectory model and the target drop point, when the flight parameters, the drop trajectory model and the target drop point are unchanged, different wind speeds and directions will make the aerial vehicle need to drop the object to be dropped at different drop positions. Therefore, the environmental parameters at least include the wind speed and the wind direction.

[0061] The target drop point of the object to be dropped refers to the position where the object to be dropped finally lands after being dropped. The target drop point can be pre-stored in the form of preset parameters. Different objects to be dropped can correspond to different target drop points. For example, in a fire fighting scene, the target drop point can be the window position of a building or the fire position.

[0062] The drop trajectory model of the object to be dropped is used to describe the moving trajectory of the object to be dropped from the drop position to the drop point. The drop trajectory model can be pre-stored in the form of preset parameters. The drop trajectory model is, for example, a parabolic model. Different objects to be dropped have different drop trajectory models. Therefore, when the drop trajectory model of the object to be dropped is obtained, the specific type of the object to be dropped can be identified first, and then the corresponding drop trajectory model is loaded. The drop trajectory model can be a model related to the drop point, the wind speed, the wind direction, the pitch angle of the aerial vehicle and the altitude of the aerial vehicle.

[0063] As an example, the drop trajectory model can be represented in the form of a differential equation as shown in formula 1:

[0064] Formula 1

[0065] wherein, represents the second derivative of displacement with respect to time, i.e. acceleration; g represents the gravitational acceleration; F drag represents the resistance caused by wind speed; m represents the mass of the object to be dropped. Since the object to be dropped is only subjected to the action of gravity and air resistance during the dropping process, the predicted landing point of the object to be dropped can be obtained by integrating the established differential equation. Among them, the resistance F drag can be calculated by formula 2:

[0066] Formula 2

[0067] wherein, C d is the drag coefficient; p is the air density; v is the speed of the object to be dropped; v w is the wind speed.

[0068] Step 120: determining the predicted landing point when the object to be dropped is dropped at different dropping times based on the dropping trajectory model, and calculating the target hit probability and determining the target dropping time according to the difference between the predicted landing point and the target landing point.

[0069] It can be understood that the flight parameters and environmental parameters of the aircraft may change at different dropping times, for example, the wind speed, wind direction, speed and attitude of the aircraft may change at different times, thereby affecting the landing point of the object to be dropped. Therefore, the dropping trajectory model can be used to simulate the predicted landing point of the same object to be dropped at different dropping times. For example, first determine the flight parameters and environmental parameters at different dropping times, and then input the flight parameters and environmental parameters at the same dropping time into the dropping trajectory model to obtain the output predicted landing point. Then determine the target hit probability according to the difference between the predicted landing point and the target landing point, and determine the target dropping time from a plurality of different dropping times. Among them, the target dropping time does not exceed the longest dropping waiting time.

[0070] It can be understood that the predicted landing point refers to the position where the object to be dropped is predicted to fall by using the trajectory dropping model combined with the flight parameters and environmental parameters. The target landing point refers to the position that the object to be dropped needs to hit. Therefore, the difference between the predicted landing point and the target landing point can be negatively correlated with the target hit probability, that is, the smaller the difference, the closer the predicted landing point to the target landing point, and the higher the target hit probability.

[0071] Step 130: determining the target dropping point of the object to be dropped according to the flight parameters, the environmental parameters, the dropping trajectory model and the target landing point.

[0072] As described above, the drop trajectory model is a model about the drop point, the wind speed, the wind direction, the aircraft pitch angle and the aircraft height. That is, after inputting the drop point, the wind speed, the wind direction, the aircraft pitch angle and the aircraft height into the drop trajectory model, the drop point of the object to be dropped output by the drop trajectory model can be obtained. Conversely, if the target drop point, the wind speed, the wind direction, the aircraft pitch angle and the aircraft height are input into the inverse function of the model, the target drop point of the object to be dropped can be deduced. That is, according to the drop trajectory described by the drop trajectory model, the object to be dropped can fall to the target drop point when dropped at the target drop point. Among them, the wind speed and the wind direction can be obtained from the environmental parameters, and the flight height and the pitch angle can be obtained from the flight parameters. Exemplarily, the target drop point can be obtained by formula 3:

[0073] Formula 3

[0074] Wherein, In this embodiment, the target drop point refers to the target drop point; The inverse function of the drop trajectory model refers to the inverse function of the drop trajectory model; X target The target drop point refers to the target drop point; θ ptich The pitch angle refers to the pitch angle; h refers to the flight height.

[0075] Optionally, after determining the target drop point, if the aircraft is not currently at the target drop point, the aircraft is controlled to fly to the target drop point to wait for dropping.

[0076] Step 140: When the target hit probability is greater than the probability threshold or the target drop time is reached, the object to be dropped is dropped by the aircraft at the target drop point.

[0077] As an example, when the target hit probability is greater than the probability threshold, it means that the difference between the predicted drop point and the target drop point is small, and at this time the object to be dropped can be controlled to be dropped by the aircraft at the target drop point. As another example, when the target drop time is reached, the object to be dropped is controlled to be dropped by the aircraft at the target drop point.

[0078] It can be seen that the trigger conditions for the aircraft to drop the object to be dropped include two, one is that the target hit probability is greater than the probability threshold, and the other is that the target drop time is reached. When any trigger condition is met, the object to be dropped can be triggered to be dropped.

[0079] As can be seen, the present application provides an aircraft-based delivery method that uses a delivery trajectory model to predict the predicted landing point of the object at different delivery times. This method then determines the target hit probability corresponding to different delivery times and the target delivery time, enabling the aircraft to autonomously plan the delivery of the object at the appropriate time (when the target hit probability exceeds a threshold or the target delivery time is reached). Furthermore, the method utilizes flight parameters, environmental parameters, and the delivery trajectory model to determine the target delivery point, enabling the aircraft to autonomously plan the delivery of the object at the appropriate location, thus giving the aircraft the ability to autonomously plan delivery.

[0080] Steps 110 to 130 are described in detail below.

[0081] According to some embodiments of the present application, the calculation process of the target hit probability in step 120 may specifically include steps 121 and 122.

[0082] Step 121: Calculate a basic hit probability based on the difference between the predicted landing point and the target landing point.

[0083] For example, the gap can be used to calculate the basic hit probability by a function based on a Gaussian distance kernel. For example, the hit probability can be defined as a function P based on a Gaussian distance kernel as shown in Formula 4. hit (t).

[0084] Formula 4

[0085] Among them, X pred (t) refers to the predicted landing point, which is related to the delivery time, that is, different delivery times may have different predicted landing points; It refers to the Euclidean distance between the predicted landing point and the target landing point; σ refers to the bandwidth parameter of the function based on the Gaussian distance kernel.

[0086] It can be seen that the basic hit probability is also related to the delivery time. The basic hit probability under different delivery times can be calculated using Formula 4.

[0087] Step 122: Correcting the basic hit probability based on the disturbance index affecting the aircraft's attitude stability and the corresponding disturbance threshold to obtain the target hit probability; wherein the disturbance index includes the aircraft's horizontal disturbance angular velocity, vertical velocity, and wind speed change rate.

[0088] The aircraft's attitude stability affects the hit probability. Understandably, the hit probability will be significantly different when dropping an object at the same location while the aircraft is trembling versus when it is stable. Therefore, when calculating the target hit probability of hitting the target landing point, it is necessary to consider the impact of disturbance indicators that affect the aircraft's attitude stability on the hit probability.

[0089] Specifically, the disturbance indicators include a horizontal disturbance angular velocity of the aircraft, a vertical speed of the aircraft, and a wind speed change rate. The horizontal disturbance angular velocity of the aircraft refers to the angular velocity of the aircraft in the horizontal plane, and the corresponding disturbance threshold is a disturbance angular velocity threshold. The disturbance angular velocity threshold can be determined according to the model of the aircraft and the sensor condition thereof, and is pre-stored in the form of a preset value. The vertical speed of the aircraft refers to the flight speed of the aircraft in the vertical direction, and the corresponding disturbance threshold is a vertical speed threshold. The vertical speed threshold can be determined according to the model of the aircraft and the sensor condition thereof, and is pre-stored in the form of a preset value. The wind speed change rate refers to the change amplitude of the wind speed in the environment of the aircraft over time, and the corresponding disturbance threshold is a wind speed change rate threshold. It can be known that, if the horizontal disturbance angular velocity is too large, or the flight speed of the aircraft in the vertical direction is too large, or the wind speed change rate of the environment around the aircraft is too large, the aircraft will vibrate to affect the hit probability, and therefore the basic hit probability needs to be corrected based on the disturbance indicators and the disturbance thresholds thereof.

[0090] Specifically, first, an attitude stability weight function is constructed based on the disturbance indicators, and in the attitude stability weight function, each disturbance indicator is assigned a corresponding weight. The attitude stability weight function W(t) is shown in formula 5.

[0091] Formula 5

[0092] wherein w1, w2 and w3 are the weights corresponding to the respective disturbance indicators; is the horizontal disturbance angular velocity; and z is the vertical speed. is the wind speed change rate.

[0093] Since the dimensions of the disturbance indicators are inconsistent, normalization needs to be performed to determine reasonable weight allocation. The attitude stability weight function W(t) after normalization of the disturbance indicators is shown in formula 6.

[0094] Formula 6

[0095] wherein X i (t) is the disturbance indicator, and X i，max is the disturbance threshold corresponding to the disturbance indicator. It can be known that, when the disturbance indicator X i (t) is the horizontal disturbance angular velocity , the corresponding disturbance threshold X i，max is the disturbance angular velocity threshold ω th ; when the disturbance indicator X i (t) is the vertical speed z, the corresponding disturbance threshold X i，max is the vertical speed threshold ; and when the disturbance indicator X i(t) is the wind speed change rate When the corresponding disturbance threshold X i，max is the wind speed change rate threshold .

[0096] Finally, the basic hit probability P is calculated based on the normalized posture stability weight function W(t). hit (t) is corrected to obtain the target hit probability The correction process is shown in Formula 7.

[0097] Formula 7

[0098] Wherein, α is a correction coefficient of the disturbance term, which can be set by those skilled in the art according to actual conditions.

[0099] Of course, in addition to calculating the target hit probability in the embodiment shown in steps 121 and 122, as another embodiment, the basic hit probability before correction can also be directly determined as the target hit probability.

[0100] It can be seen that this embodiment uses a disturbance index that interferes with the stability of the aircraft's attitude to correct the basic hit probability, so that when predicting the target hit probability, the unstable factors caused by the aircraft's own jitter and wind speed changes are taken into account, thereby improving the prediction accuracy of the target hit probability and then improving the prediction accuracy of the drop timing.

[0101] According to some embodiments of the present application, determining the target delivery time based on the difference between the predicted landing point and the target landing point in step 120 may specifically include steps 123 and 124. This embodiment does not limit the order in which the target hit probability calculation process (i.e., steps 121 and 122) and the target delivery time determination process (i.e., steps 123 and 124) are executed; the target hit probability and the target delivery time may also be calculated simultaneously.

[0102] Step 123: Determine a candidate delivery time, and determine a predicted landing point when the object to be delivered is delivered at the candidate delivery time based on the delivery trajectory model.

[0103] For example, when determining the candidate delivery time for the first time, a delivery time can be randomly determined as the candidate delivery time, and then the flight parameters and environmental parameters corresponding to the candidate delivery time are determined, and the delivery trajectory model is input to obtain the output predicted landing point.

[0104] Step 124: determining a next candidate launch time based on the gap between the predicted landing point and the target landing point, and returning to the step of determining the predicted landing point of the object to be launched at the candidate launch time using the launch trajectory model until the predicted landing point and the target landing point are the same.

[0105] After obtaining the predicted landing point corresponding to the candidate launch time, the launch time can be adjusted based on the gap between the predicted landing point and the target landing point to obtain a next candidate launch time. And return to step 123. After at least one iteration, when the predicted landing point and the target landing point are the same, the candidate launch time of the current iteration can be determined as the target launch time. It can be known that at the target launch time, the predicted landing point and the target landing point are the same, that is, when the object to be launched is launched at the target launch time, the object to be launched can hit the target landing point.

[0106] It can be understood that, due to the high nonlinearity of the launch trajectory model, it is difficult to directly solve the target launch time, so in this embodiment, the launch time is taken as a variable, and the launch time is adjusted based on the gap between the predicted landing point and the target landing point in each iteration, so as to inversely deduce the target launch time by means of numerical optimization (such as Newton iteration method).

[0107] Optionally, the object to be launched has a maximum launch waiting time, which represents that the object to be launched needs to be launched within the maximum launch waiting time. Therefore, the target launch time can be determined within the maximum launch waiting time by means of numerical optimization. It can be understood that, since the target launch time at which the predicted landing point and the target landing point are the same may not be determined within the maximum launch waiting time, the application also selects a suitable launch time through the target hit probability. Moreover, if the calculation of the target hit probability also introduces a disturbance index affecting the attitude stability of the aircraft for correction, the time when the target hit probability is greater than the probability threshold may not be consistent with the target launch time. Therefore, the time corresponding to the launch of the object to be launched when the target hit probability is greater than the probability threshold may be the same as or different from the target launch time.

[0108] It can be known that, in this embodiment, the numerical optimization method is used to solve the optimal target launch time from the highly nonlinear launch trajectory model, so that the aircraft has the ability to autonomously plan the launch time.

[0109] According to some embodiments of the application, the determination process of the target landing point in step 130 can specifically include steps 131-133.

[0110] Step 131: determining an ideal launch point of the object to be launched according to the flight parameters, the environmental parameters, the launch trajectory model and the target landing point.

[0111] Exemplarily, the flight parameters include a flight height and a pitch angle, and the environmental parameters include a wind speed and a wind direction. By inputting the target landing point, the wind speed, the wind direction, the aircraft pitch angle, and the aircraft height into the inverse function of the drop trajectory model, an output ideal drop point can be obtained. Specifically, the ideal drop point can be obtained by the above formula 3, where in the formula 3, the In the embodiment, the ideal drop point is referred to.

[0112] Step 132: estimating a wind deviation and an inertia deviation based on the flight parameters and the environmental parameters; wherein the wind deviation is used to represent the deviation of the wind speed to the drop trajectory of the to-be-dropped object; and the inertia deviation is used to represent the deviation of the movement of the aircraft to the drop trajectory of the to-be-dropped object.

[0113] Exemplarily, the inertia deviation is used to represent the deviation of the movement of the aircraft to the drop trajectory of the to-be-dropped object, also known as the windless deviation. As an example, the inertia deviation can be set to 0, and as another example, the flight speed and the flight height of the aircraft can be obtained from the flight parameters, and the falling time of the to-be-dropped object can be determined based on the flight height and the drop trajectory model, and then the inertia deviation can be determined based on the flight speed and the falling time, such as determining the product of the flight speed and the falling time as the inertia deviation. Specifically, the inertia deviation The inertia deviation can be determined based on formula 8.

[0114] Formula 8

[0115] wherein v UVA is the flight speed of the aircraft; and t fall is the falling time.

[0116] In addition, the wind deviation is used to represent the deviation of the wind speed to the drop trajectory of the to-be-dropped object. As an example, the wind deviation can be approximately determined based on the resistance caused by the wind speed, the distance between the ideal drop point and the target landing point, and the mass of the to-be-dropped object. For example, the wind deviation The wind deviation can be determined based on formula 9.

[0117] Formula 9

[0118] wherein d is the distance between the ideal drop point and the target landing point, and m is the mass of the to-be-dropped object.

[0119] As another example, the wind deviation can be determined based on the wind speed and the above falling time, such as determining the product of the wind speed and the falling time as the wind deviation. Specifically, the wind deviation The wind deviation can be determined based on formula 10.

[0120] Formula 10

[0121] Step 133: correcting the ideal drop point by the wind deviation and the inertial deviation to obtain the target drop point.

[0122] Exemplarily, the wind deviation and the inertial deviation can be subtracted from the ideal drop point to obtain the target drop point, as shown in formula 11.

[0123] Formula 11

[0124] Of course, in addition to calculating the target drop point in the embodiment shown in steps 131-133, as another embodiment, the ideal drop point before correction can also be directly determined as the target drop point.

[0125] It can be known that the embodiment considers the influence of the flight speed of the aircraft and the wind speed on the deviation of the drop trajectory when the aircraft drops the to-be-dropped object, and then corrects the ideal drop point by using the estimated wind deviation and inertial deviation, thereby improving the prediction accuracy of the target drop point.

[0126] In addition, the application also provides a speed control method of an aircraft, which is used for stably controlling the speed of the aircraft on the basis of the total mass of the aircraft and the disturbance to the speed of the aircraft in the flight process of the aircraft. Optionally, the method can be executed on the basis of any of the above embodiments. In this way, the speed of the aircraft can be stably controlled on the basis of the disturbance caused by the total mass difference of the to-be-dropped object before and after the drop to the aircraft in the flight process and the drop process of the aircraft. Specifically, the speed of the aircraft can be stably controlled through steps 210-250 as shown in the following. Figure 2

[0127] Step 210: parsing the vertical thrust component of the aircraft from the throttle command of the aircraft.

[0128] Exemplarily, the throttle command of the aircraft can be mapped to the thrust T of the aircraft in the flight control system. Then, the projection of the thrust in the Z-axis (i.e., the vertical direction) of the inertial coordinate system can be determined as the vertical thrust component of the aircraft. Wherein, the thrust of the aircraft at different times can be the same or different, and correspondingly, the vertical thrust component can also be the same or different, so that in step 210, the current throttle command can be mapped to the current thrust T(t), and then the projection of the thrust T(t) in the Z-axis of the inertial coordinate system is determined as the vertical thrust component T z (t).

[0129] Step 220: estimating the current vertical disturbance of the aircraft by using the current vertical speed observation value and the historical vertical speed estimation value of the aircraft through the first extended state observer.

[0130] ​Exemplarily, an Extended State Observer (ESO) is an observer that can estimate both the state variables and the unknown disturbances of a system simultaneously. The core idea is to treat the unknown disturbance as an extended state variable and estimate it using an observer. By compensating for the estimated disturbance, the anti-interference ability of the control system can be effectively improved.

[0131] In the present embodiment, a first Extended State Observer (hereinafter referred to as first ESO) is used to estimate the disturbance affecting the vertical speed of the aircraft, which is an unmodeled disturbance caused by air flow or simulation error. The first ESO can periodically estimate the disturbance in the vertical direction (hereinafter referred to as vertical disturbance) and the vertical speed of the aircraft (hereinafter referred to as vertical speed estimate). Specifically, the first ESO uses the current vertical observed speed observation value v z (t) and the historical vertical speed estimate (t-1) to estimate the current vertical disturbance (t) of the aircraft. Wherein, the current vertical observed speed observation value v z (t) refers to the component of the flight speed of the aircraft in the vertical direction, which can be obtained by the speed sensor carried by the aircraft; the historical vertical speed estimate (t-1) refers to the vertical speed estimate estimated by the first ESO in the historical period, for example, the last period.

[0132] Step 230: estimating the current vertical speed estimate of the aircraft by the first Extended State Observer using the estimated historical vertical disturbance and the vertical thrust component.

[0133] Wherein, the historical vertical disturbance (t-1) refers to the vertical disturbance estimated by the first ESO in the historical period, for example, the last period. Wherein, the estimated current vertical speed estimate (t) is the estimated value after observation correction. The observation correction is based on the difference between the current vertical observed speed observation value v z (t) and the historical vertical speed estimate (t-1).

[0134] In combination with steps 220-230, the first ESO dynamic equation can be shown in formula 12.

[0135] Formula 12

[0136] Wherein, in the first line of formula 12, is the acceleration predicted according to the mechanical model, which is the acceleration in the vertical direction in the inertial coordinate system, and the acceleration is determined by the thrust, gravity and disturbance. It can be understood that the system behavior is calculated by using the mechanical equation of estimating disturbance. M is the total mass of the aircraft (including the object to be dropped). is the correction term, which uses the current vertical speed observation value v z (t) and the error between the historical vertical speed estimate value (t-1) to quickly correct the acceleration predicted by the mechanical model. L1 is the first level ESO gain. Increasing the value of L1 can improve the response speed, but it is also susceptible to noise. (t) is the current vertical acceleration estimate value. Since the estimation period interval of the first ESO is small, it is 0.002 seconds, therefore the vertical acceleration estimate value and the vertical speed estimate value satisfy: (t)= v z (t-1)+ (t-1). Thus, the current vertical speed estimate value (t) can be determined by using the historical vertical acceleration estimate value (t-1).

[0137] In the second line of formula 12, since the current vertical disturbance (t) is not directly observable, it is indirectly estimated by the difference between the system behavior and the expectation. When the current vertical speed estimate value is always a little slower than the current vertical speed observation value, it can be considered that there is an additional disturbance to slow down, so the error is accumulated to the current vertical disturbance (t). Wherein, L2 is the second level ESO gain, which is used to control the speed and sensitivity of disturbance estimation. of is the acceleration of the current vertical disturbance, which uses the acceleration of the current vertical disturbance to obtain the current vertical disturbance .

[0138] Step 240: Estimate the mass of the aircraft based on the force acting on the aircraft in the vertical direction to obtain the current estimated mass; wherein in the unbalanced state, the force acting on the aircraft in the vertical direction includes vertical thrust, gravity and vertical disturbance; in the balanced state, the force acting on the aircraft in the vertical direction includes vertical thrust and gravity.

[0139] In the unbalanced state, the vertical disturbance of the aircraft cannot be ignored, so the force acting on the aircraft in the vertical direction includes vertical thrust, gravity and vertical disturbance. At this time, the mass estimation can be carried out based on the vertical thrust, gravity and vertical disturbance. The estimated mass is the total mass of the aircraft including the object to be dropped, as shown in formula 13-1.

[0140] Formula 13-1

[0141] wherein, is the current vertical disturbance estimated based on step 220, and g is the gravity acceleration.

[0142] While in the equilibrium state, the vertical disturbance of the aircraft can be ignored, and thus the force in the vertical direction includes the vertical thrust and the gravity. At this time, the mass estimation can be performed based on the vertical thrust and the gravity. The estimated mass As shown in equation 13-2.

[0143] Equation 13-2

[0144] Step 250: performing speed control on the aircraft based on the current vertical speed estimation value and the current estimated mass.

[0145] It can be understood that the sensor for measuring the flight speed in the aircraft occasionally fluctuates, resulting in unreliable observation of the flight speed noise. Therefore, the vertical speed estimation by the first ESO avoids the influence of the sensor fluctuation on the stable control of the speed of the aircraft. In addition, the mass of the aircraft changes before and after the object is launched. The vertical disturbance estimated by the first ESO is used to further estimate the overall mass of the aircraft, so as to provide real-time feedback for the throttle controller, so that the throttle controller can automatically match the actual mounting state of the aircraft, achieve the purpose of disturbance rejection and self-adaptation, and avoid the imbalance of the aircraft due to the sudden decrease in mass after the object is launched. In addition, the embodiment identifies the part of the vertical thrust component that is output more to compensate for the disturbance, so as to compensate for the disturbance caused by the gravity or air resistance of the object to be launched.

[0146] In addition, the application also provides an attitude control method of an aircraft, which is used for stably controlling the attitude of the aircraft based on the total mass of the aircraft and the disturbance in the flight process of the aircraft. It can be understood that the object to be launched mounted on the aircraft not only increases the overall mass of the aircraft, but also deviates from the center of mass of the aircraft, thereby bringing an additional moment of rotation to the aircraft. When the aircraft performs attitude control, the additional moment of rotation needs to be offset to maintain the stability of the attitude. For example, if the object to be launched is mounted on one side of the body of the aircraft, the aircraft will be more difficult to rotate in the direction of the side, and a larger moment of rotation needs to be applied to offset the additional moment of rotation caused by the eccentric mounting of the object to be launched, which is manifested as an increase in the moment of inertia of the aircraft. Therefore, before and after the launch of the object to be launched, the overall force moment of the aircraft changes, and the attitude of the aircraft needs to be stably controlled.

[0147] Optionally, the method can be performed on the basis of any of the above embodiments. Thus, the attitude of the aircraft can be stably controlled based on the disturbance caused by the total mass difference of the aircraft before and after the object is launched during the flight process and the object launching process. Specifically, the attitude of the aircraft can be stably controlled through steps 310-330 as shown in the following. Figure 3

[0148] Step 310: estimating the current angular velocity rate of the aircraft by the second extended state observer using the target moment of inertia of the aircraft, the estimated historical disturbance torque, and the current flight torque.

[0149] The second extended state observer (hereinafter referred to as the second ESO) is used to estimate the disturbance torque and the angular velocity rate. The disturbance torque is the additional rotational torque caused by the eccentric mounting of the object to be launched as described above. The second ESO can periodically estimate the disturbance torque and the angular velocity rate. Specifically, the second ESO estimates the current angular velocity rate of the aircraft based on the target moment of inertia J of the aircraft, the historical disturbance torque and the current aircraft torque τ cmd (t). The determination process of the target moment of inertia J will be described below. The historical disturbance torque refers to the disturbance torque estimated by the second ESO in the historical period, for example, the last period. The current aircraft torque τ cmd (t) can be obtained by the flight control system. The current angular velocity rate (t) is the estimated value after observation correction. The observation correction is based on the difference between the current angular velocity observation value (t) and the historical angular velocity estimation value (t-1).

[0150] Step 320: estimating the current disturbance torque generated by the object to be launched on the aircraft by the second extended state observer using the current angular velocity observation value and the historical angular velocity estimation value.

[0151] The current angular velocity observation value ω(t) can be obtained by the sensor carried by the aircraft. The historical angular velocity estimation value (t-1) refers to the angular velocity estimation value estimated by the second ESO in the historical period, for example, the last period.

[0152] In combination with steps 310-320, the dynamic equation of the second ESO can be shown in formula 14-1.

[0153] Formula 14-1

[0154] ​The first line of Equation 14-1 is the state estimator, which combines the dynamics prediction and the observation error feedback. is based on the classical rigid body dynamics equation, considering the mass disturbance as the main source of disturbance torque. J represents the target moment of inertia of the aircraft, represents the estimated historical disturbance torque. represents the historical angular velocity estimate. is the gyroscopic term. In the small angle velocity scenario, the gyroscopic term can be simplified, and thus Equation 14-1 can be simplified to Equation 14-2. is the observation error feedback, i.e., the observation correction based on the difference between the current angular velocity observation and the historical angular velocity estimate. The current angular velocity rate is estimated by the first line of Equation, which indicates how the current angular velocity state is determined by the control command (current flight torque) and the disturbance torque. The angular velocity rate can be obtained by the second line of Equation 14-2.

[0155] Equation 14-2

[0156] The second line of Equation 14-1 and Equation 14-2 is the disturbance observer, which adjusts the estimate of the disturbance torque based on the angular velocity error. Here, is a 3*3 observer gain matrix, which determines the response speed of the disturbance estimate. is the acceleration of the current disturbance torque, which can be used to obtain the disturbance torque. It can be understood that, since the disturbance torque cannot be directly modeled or measured, the disturbance torque can be estimated and corrected using the observation error of the angular velocity. That is, if the current angular velocity observation deviates from the current angular velocity estimate, it means that there is an unknown disturbance torque, and at this time the second ESO can automatically estimate and correct the disturbance torque.

[0157] Step 330: controlling the attitude of the aircraft based on the current angular velocity rate

[0158] After the current angular velocity rate and the current disturbance torque are estimated by the second ESO, the attitude of the aircraft can be controlled. Exemplarily, the estimated current disturbance torque may also be fed back to the attitude controller, so that the attitude controller outputs include the current disturbance torque ​The control instruction is compensated, thereby achieving active compensation of the external input of the system. When there is unstructured disturbance, i.e., weight change, the control instruction can be corrected in real time to ensure the attitude stability and avoid imbalance of the aircraft caused by sudden change of the weight and force of the aircraft after the payload is launched.

[0159] In addition, the second ESO is used to estimate the angular velocity and the disturbance torque because the disturbance torque cannot be directly modeled or measured. The reason why the disturbance torque cannot be directly modeled or measured is that the mass of the payload and the inertia of the aircraft change. For example, in some scenarios, the aircraft carries liquid fire extinguishing bombs (payloads). As the liquid in the liquid fire extinguishing bomb decreases, the mass of the payload changes. In addition, the liquid in the liquid fire extinguishing bomb moves with the aircraft, causing the inertia of the aircraft to change. In other scenarios, the payload can be approximated as a rigid body, and a part of the payload is fixedly connected to the body. For example, the aircraft carries dry powder fire extinguishing bombs (the fire extinguishing bomb is fixed to the aircraft, and the powder in the fire extinguishing bomb is launched), and the size parameters of the fire extinguishing bomb are known. At this time, the disturbance torque formed by the mounting position and the mass of the payload has been modeled and can be estimated, and the estimation of the angular velocity and the disturbance torque can be performed by the following steps S1-S2 instead of steps 310-320.

[0160] Step S1: determining the disturbance torque generated by the payload on the aircraft based on the mass of the payload, the position vector of the payload relative to the center of mass of the aircraft, and the disturbance torque model.

[0161] For example, the mass of the payload can be determined by weighing in advance and pre-stored in the device. Alternatively, the mass of the payload can be determined based on the current estimated mass Subtracting the mass of the aircraft body, the mass of the payload is obtained, wherein the current estimated mass The estimation process is described above and will not be repeated here.

[0162] In addition, the mounting position of the payload is fixed and can be determined, so the position vector of the payload relative to the center of mass of the aircraft can be pre-stored.

[0163] The disturbance torque model is shown in formula 15.

[0164] Formula 15

[0165] wherein, is the position vector of the payload relative to the center of mass of the aircraft, is the linear acceleration of the aircraft in the inertial coordinate system, which can be measured by the IMU (Inertial Measurement Unit) of the aircraft, wherein the vertical acceleration described in the above embodiment is the linear acceleration acceleration component in the vertical direction. Thus, based on the mass of the object to be dropped , the position vector of the object to be dropped relative to the center of mass of the aircraft , and the disturbance moment model, the disturbance moment generated by the object to be dropped on the aircraft can be determined .

[0166] Step S2: determine the current angular rate of change of the aircraft based on the target moment of inertia of the aircraft, the current flight moment, and the disturbance moment.

[0167] The classical rigid body dynamics equation after simplifying the gyroscopic term is shown in Equation 16.

[0168] Equation 16

[0169] Thus, the ratio of the difference between the current flight moment and the disturbance moment and the target moment of inertia J is the current angular rate of change .

[0170] In addition, regarding the determination process of the target moment of inertia, as an example, the moment of inertia of the aircraft body can be determined as the target moment of inertia. As another example, the moment of inertia of the aircraft body can be corrected based on the influence of the object to be dropped currently mounted on the aircraft on the moment of inertia of the aircraft, which can specifically include steps 410-430 as shown in Equation 17. Figure 4

[0171] Step 410: determine the compensated moment of inertia of the object to be dropped currently mounted on the aircraft relative to the aircraft.

[0172] Exemplarily, the point mass can be converted into the influence on the moment of inertia of the center of mass based on the parallel axis theorem to obtain the compensated moment of inertia. Specifically, the compensated moment of inertia is shown in Equation 17.

[0173] Equation 17

[0174] where m i is the mass of the i-th object to be dropped, r i is the position vector of the i-th object to be dropped relative to the center of mass of the aircraft, i.e., the above The position vectors of different objects to be dropped relative to the center of mass of the aircraft can be the same or different. I is the identity matrix, is a scalar multiplied by the identity matrix, and is a moment of inertia compensation term related to the square of the distance of the object to be dropped to the center of mass, is a matrix formed by the outer product, which has a rank of 1 and is used to remove the inertia contribution around its own axis. ​

[0175] Step 420: obtaining the body inertia moment of the aircraft.

[0176] The body inertia moment J of the aircraft UAV The obtaining and pre-storing can be realized.

[0177] Step 430: determining the target inertia moment based on the body inertia moment and the compensation inertia moment.

[0178] The body inertia moment J is determined UAV The compensation inertia moment The sum of the body inertia moment and the compensation inertia moment is the target inertia moment J, that is, the target inertia moment J can be expressed as: J = J UAV + .

[0179] It can be known that the embodiment corrects the body inertia moment of the aircraft based on the influence of the to-be-dropped object currently mounted on the aircraft on the inertia moment of the aircraft, thereby improving the estimation accuracy of the angular velocity.

[0180] In addition, on the basis of any of the above embodiments, one of the application scenarios of the present application is a fire extinguishing scene, the aircraft includes a drone, and the to-be-dropped object is a fire bomb, including a fire extinguishing bomb, a window breaking bomb, etc. The drone can simultaneously mount multiple fire bombs, and the drone can simultaneously mount multiple different types of fire bombs. Different types of fire bombs have different masses and can be mounted in the same mounting position of the drone or different mounting positions. Before executing any of the above embodiments, the mass and position characteristics of the bomb type can be identified through a sensor or other algorithm. In addition, different bomb types have different drop trajectory models, so the corresponding drop trajectory model can be loaded according to the bomb type identification result to increase the stability of the aircraft and the accuracy of bomb dropping. It can be known that the use of the method provided by any of the above embodiments for bomb dropping in the fire extinguishing scene endows the drone with autonomous planning capabilities of bomb dropping dynamic window prediction and drop strategy switching, thereby improving the accuracy of bomb dropping.

[0181] Based on the aircraft-based bomb dropping method described in any of the above embodiments, the present application further provides a computer program product including one or more computer programs or instructions. The computer programs or instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another. The computer program is executed by a processor to realize the aircraft-based bomb dropping method described in any of the above embodiments.

[0182] Based on the aircraft-based bomb dropping method described in any of the above embodiments, the present application further provides a structure diagram of a bomb dropping control device as shown in Figure 5 Figure 5 ​At the hardware level, the device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and of course can also include other hardware required by the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs to implement the aircraft-based object throwing method described in any of the embodiments. Among them, the object throwing control device can be carried in the aircraft, or in the control end connected with the aircraft in communication.

[0183] The application also provides a computer storage medium, the storage medium stores a computer program, and the computer program is executed by a processor to implement the aircraft-based object throwing method described in any of the embodiments.

[0184] In several embodiments provided in the present application, it should be understood that the disclosed apparatus and method can also be implemented in other ways. The apparatus embodiments described above are only schematic, for example, the flowcharts and block diagrams in the drawings show the possible implementation architectures, functions and operations of the apparatus, method and computer program product according to the embodiments of the present application. In this regard, each block in the flowcharts or block diagrams can represent a module, a program segment or a part of code, which contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur in different orders from that shown in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and the combination of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system for executing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0185] In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0186] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts of the prior art that make contributions or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0187] The above merely provides an example of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0188] The above merely provides an example of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0189] It should be noted that, in this document, the terms such as first and second are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.

Claims

1. An aircraft-based object projection method, characterized by, The aircraft carries a to-be-dropped object; the method comprises: Obtaining flight parameters and environmental parameters of the aircraft, and a dropping trajectory model and a target landing point of the to-be-dropped object; Determining a predicted landing point when the to-be-dropped object is dropped at different dropping times based on the dropping trajectory model, and calculating a target hit probability and determining a target dropping time according to the difference between the predicted landing point and the target landing point; Determining a target dropping point of the to-be-dropped object according to the flight parameters, the environmental parameters, the dropping trajectory model and the target landing point; When the target hit probability is greater than a probability threshold or the target dropping time is reached, controlling the aircraft to drop the to-be-dropped object at the target dropping point; In the flight process and the object dropping process of the aircraft, the method further comprises: Estimating the current angular velocity change rate of the aircraft by a second extended state observer using the target moment of inertia of the aircraft, the estimated historical disturbance torque and the current flight torque; Estimating the current disturbance torque generated by the to-be-dropped object on the aircraft by the second extended state observer using the current angular velocity observation value and the historical angular velocity estimation value; Controlling the attitude of the aircraft based on the current angular velocity change rate.

2. The method of claim 1, wherein, The target hit probability is calculated according to the difference between the predicted landing point and the target landing point, comprising: Calculating a basic hit probability according to the difference between the predicted landing point and the target landing point; Correcting the basic hit probability based on a disturbance index and a corresponding disturbance threshold that affect the attitude stability of the aircraft to obtain the target hit probability; wherein the disturbance index includes the horizontal disturbance angular velocity, the vertical velocity and the wind speed change rate of the aircraft.

3. The method of claim 1, wherein, The target dropping time is determined by the following steps: Determining a candidate dropping time, and determining a predicted landing point when the to-be-dropped object is dropped at the candidate dropping time based on the dropping trajectory model; Determining a next candidate dropping time based on the difference between the predicted landing point and the target landing point, and returning to the step of determining the predicted landing point when the to-be-dropped object is dropped at the candidate dropping time based on the dropping trajectory model, until the predicted landing point and the target landing point are the same, and determining that the candidate dropping time of the current iteration round is the target dropping time.

4. The method of claim 1, wherein, The target dropping point of the to-be-dropped object is determined according to the flight parameters, the environmental parameters, the dropping trajectory model and the target landing point, comprising: Determining an ideal dropping point of the to-be-dropped object according to the flight parameters, the environmental parameters, the dropping trajectory model and the target landing point; Estimating wind deviation and inertial deviation based on the flight parameters and the environmental parameters; wherein the wind deviation is used to represent the deviation of the wind speed on the dropping trajectory of the to-be-dropped object; and the inertial deviation is used to represent the deviation of the movement of the aircraft on the dropping trajectory of the to-be-dropped object; Correcting the ideal dropping point using the wind deviation and the inertial deviation to obtain the target dropping point.

5. The method according to any of claims 1 to 4, characterized in that In the flight process and the object dropping process of the aircraft, the method further comprises: Parsing the vertical thrust component of the aircraft from the throttle command of the aircraft; estimating a current vertical disturbance of the aerial vehicle by a first extended state observer using a current vertical velocity observation of the aerial vehicle and a history vertical velocity estimation; estimating a current vertical velocity estimation of the aerial vehicle by the first extended state observer using the estimated history vertical disturbance and the vertical thrust component; estimating a current estimation of the mass of the aerial vehicle based on forces acting on the aerial vehicle in a vertical direction, wherein the forces acting on the aerial vehicle in the vertical direction include the vertical thrust, the gravity and the vertical disturbance in a non-equilibrium state, and the vertical thrust and the gravity in an equilibrium state; controlling a velocity of the aerial vehicle based on the current vertical velocity estimation and the current estimation of the mass.

6. The method of claim 1, wherein, The method further comprises: determining a compensation moment of inertia of a payload to be dropped by the aerial vehicle relative to the aerial vehicle; obtaining a body moment of inertia of the aerial vehicle; determining the target moment of inertia based on the body moment of inertia and the compensation moment of inertia.

7. A computer program product, characterised in that, The computer program product comprises a computer program which, when executed by a processor, implements the method of any one of claims 1-6.

8. A throw control device, characterized by The apparatus comprises: a processor; a memory for storing processor-executable instructions; wherein the processor, when invoking the executable instructions, implements the operations of the method of any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, A computer program product having stored thereon computer instructions which, when executed by a processor, implement the steps of the method of any one of claims 1-6.

Images