A Low-Battery Autonomous Landing Decision Method for UAVs to Take Off and Land at Different Locations

Abstract

The present invention discloses a low-power autonomous landing decision method for a drone to take off and land at different locations, including the following steps: S1, enter the low-power logic; S2, calculate the straight-line distance L0 between the drone and the takeoff point; S3, determine whether the drone mission route type is takeoff and landing in place; S4, calculate the power required to return directly to the landing point from the current position; S5, collect the real-time power C t ; S6, switch the flight mode of the drone according to different power states; S7, judge the type of the target landing point after the drone triggers a return due to low power. The drone can distinguish the mission route type and select the nearest low-power return target point according to the real-time situation.

Description

Technical Field

[0001] The present invention relates to the field of autonomous heading planning for unmanned aerial vehicles (UAVs), and particularly to a low-power autonomous landing decision method for UAVs taking off and landing at different locations. Background Art

[0002] Vertical takeoff and landing UAVs are widely used in the inspection of power and communication equipment. Their operation mode is mainly takeoff and landing at different locations, and the operation distance is generally designed to be between 100 km and 200 km according to the rated flight time of the aircraft. During the long-distance operation process, UAVs need to face variable and complex environments. At the same time, the actual flight time of UAVs will also be reduced due to the influence of harsh environments. In this case, UAVs will face the risk of low power. The action logic and operation state for dealing with the low-power state have become an important link in maintaining the flight safety of UAVs.

[0003] The existing low-power return logic generally executes a return or a direct landing in the case of a UAV with low power. If the aircraft is very far from the starting position at this time, the existing power cannot maintain the aircraft's return to the starting position; however, if it is selected to land on the spot, the UAV is unknown about the landing point environment. Therefore, during operation, it is generally required that the staff participating in the operation manually handle the return and landing logic of the UAV. Such an operation process requires the staff to be familiar with the geographical environment of the operation area and to closely monitor the flight dynamics of the UAV in real time and quickly intervene in case of crisis. Even so, it is very difficult to ensure the safe and reliable landing of the aircraft in the low-power state. It cannot meet the safe, reliable, and convenient business requirements in the operation scenario. Therefore, we have designed a low-power autonomous landing decision method for UAVs taking off and landing at different locations to solve the above-mentioned problems. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a low-power autonomous landing decision method for UAVs taking off and landing at different locations to solve the risk problems of the UAV operation in a complex flight environment, especially when performing the takeoff and landing route task at different locations. When the aircraft encounters a low-power state, it is impossible to return normally due to the too long direct return distance, and then the risk of landing on the spot in an unknown environment; to assist the on-site staff to understand the dynamics of the UAV in real time and automatically make decisions on tasks and route switching in the case of low power, and solve the problem of low-power fault handling during the operation of the takeoff and landing route at different locations in a long-distance complex environment.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: A low-power autonomous landing decision method for UAVs taking off and landing at different locations, comprising the following steps:

[0006] S1. Enter the low-power logic;

[0007] S2. Calculate the straight-line distance L0 between the UAV and the takeoff point;

[0008] S3. Determine whether the UAV mission route type is takeoff and landing in place;

[0009] S4. Calculate the power required to return directly to the landing point from the current position;

[0010] S5. Collect the real-time power C t ;

[0011] S6. Switch the flight mode of the UAV according to different power states;

[0012] S7. After the UAV triggers a return due to low power, determine the type of the target landing point.

[0013] The beneficial effect of the present invention is: It can distinguish the mission route type and select the nearest low-power return target point according to the real-time situation.

[0014] On the basis of the above technical solution, the present invention can also be improved as follows.

[0015] Further, S31. If the UAV mission route type is takeoff and landing in place, assign L0 to the landing measurement distance L;

[0016] S32. If the UAV mission route type is not takeoff and landing in place, calculate the straight-line distance L1 between the UAV and the off-site landing point.

[0017] Further, S321. If L1 is less than 1.2 times of L0, assign L1 to the landing measurement distance L and set the off-site landing point as the target landing point;

[0018] S322. If L1 is greater than or equal to 1.2 times of L0, assign L0 to the landing measurement distance L and set the takeoff point as the target landing point.

[0019] Further, input parameters:

[0020] 1) Vertical / landing height: Set range H Land ;

[0021] 2) Distance to the target landing point: L;

[0022] 3) Wind speed: V Wind The direction towards the nose of the aircraft is positive;

[0023] 4) Landing speed: V Land ;

[0024] 5) Return power set by the ground station: C Rest％ ;

[0025] 6) Cruise airspeed: V Asp ;

[0026] 7) Initial battery capacity: C0;

[0027] 8) Landing current: I Land ;

[0028] 9) Cruise current: I Cruise ;

[0029] Calculation formula:

[0030] 1) Capacity consumed during vertical landing:

[0031] 2) Capacity consumed by the fixed-wing flight to the target landing point:

[0032]

[0033] 3) Remaining capacity to trigger return: C Trig = C Rest％ × C0 + C Land + C Distance

[0034] The further beneficial effect of adopting the above is: It is possible to calculate whether the aircraft can smoothly reach the normal target landing point along the route based on the real-time obtained power of the UAV.

[0035] Further, S61, if C t is less than 0.8 times of C trig , and less than 1.2 times of C Land , and the time is greater than 30s, the UAV sends a low-power warning to the ground station, and the flight mode automatically switches to landing on the spot;

[0036] S62, if C t is less than C trig , and the time is greater than 30s, the UAV sends a low-power warning to the ground station, and the UAV mode automatically switches to the target landing point;

[0037] S63, if C t is less than 1.2 times of C trig , and the time is greater than 10s, the UAV only sends a low-power warning to the ground station.

[0038] Further, S71, if the type of the original route landing point is the same as that of the target landing point, then determine whether the UAV has a descending and hovering point;

[0039] S72, if the type of the original route landing point is different from that of the target landing point, then determine the type of the target landing point.

[0040] Further, S711, if the type of the original route landing point is the same as that of the target landing point, and the route includes a descending and hovering point, then the UAV directly flies to the descending and hovering point of the original route;

[0041] S712. If the type of the original flight route landing point is the same as that of the target landing point, but the flight route does not include a height reduction hovering point, then determine the type of the target landing point.

[0042] Further, S7121. If the type of the original flight route landing point is the same as that of the target landing point, but the flight route does not include a height reduction hovering point, then determine the type of the target landing point. If it is a take-off point, the UAV flies towards the first waypoint of the flight route.

[0043] S7122. If the type of the original flight route landing point is the same as that of the target landing point, but the flight route does not include a height reduction hovering point, then determine the type of the target landing point. If it is an off-site landing point, the UAV flies towards the second last waypoint of the flight route.

[0044] Further, S721. If the type of the original flight route landing point is different from that of the target landing point, and if the type of the target landing point is a take-off point, the UAV flies towards the first waypoint of the flight route.

[0045] S722. If the type of the original flight route landing point is different from that of the target landing point, and if the type of the target landing point is an off-site landing point, the UAV flies towards the second last waypoint of the flight route.

[0046] The beneficial effects of the above further measures are as follows: When the UAV cannot reach the normal target landing point, it flies directly along a straight line towards the target landing point to ensure the safe and reliable mission operation of the UAV; A relatively reliable flight trajectory can be formulated according to the situation of the original flight route. After reducing the height and hovering before reaching the target point, it then automatically lands near the target landing point. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is the low-power autonomous decision-making flowchart for the off-site take-off and landing of the UAV according to the method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0048] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0049] Embodiment 1

[0050] As Figure 1 shown, a low-power autonomous landing decision-making method for the off-site take-off and landing of a UAV includes:

[0051] S1. Enter the low-power logic;

[0052] S2. Calculate the straight-line distance L0 between the UAV and the take-off point;

[0053] S3. Determine whether the type of the UAV mission flight route is in-situ take-off and landing;

[0054] S4. Calculate the power required to return to the landing point in a straight line from the current position;

[0055] S5. Collect the real-time power C t ;

[0056] S6. Switch the flight mode of the UAV according to different power states;

[0057] S7. After the UAV triggers a return due to low power, determine the type of the target landing point.

[0058] Embodiment 2

[0059] As Figure 1 shown, this embodiment is a further improvement based on Embodiment 1, and is specifically as follows:

[0060] S31. If the mission route type of the UAV is takeoff and landing in place, assign L0 to the landing measurement distance L;

[0061] S32. If the mission route type of the UAV is not takeoff and landing in place, calculate the straight-line distance L1 between the UAV and the off-site landing point

[0062] S321. If L1 is less than 1.2 times L0, assign L1 to the landing measurement distance L, and set the off-site landing point as the target landing point;

[0063] S322. If L1 is greater than or equal to 1.2 times L0, assign L0 to the landing measurement distance L, and set the takeoff point as the target landing point.

[0064] Input parameters:

[0065] 1) Vertical / landing height: The setting range is H Land ;

[0066] 2) Distance to the target landing point: L;

[0067] 3) Wind speed: V Wind The direction towards the nose of the aircraft is positive;

[0068] 4) Landing speed: V Land ;

[0069] 5) Return power set by the ground station: C Rest％ ;

[0070] 6) Cruise airspeed: V Asp ;

[0071] 7) Initial battery capacity: C0;

[0072] 8) Landing current: I Land ;

[0073] 9) Cruise current: I Cruise 。

[0074] Calculation formula:

[0075] 1) Vertical landing consumption capacity:

[0076] 2) Capacity consumed by the fixed-wing flight to the target landing point:

[0077]

[0078] 3) Remaining capacity to trigger the return flight: C Trig =C Rest％ ×C0 + C Land + C Distance 。

[0079] Example 3

[0080] As Figure 1 shown, this example is a further improvement based on Example 1, and the details are as follows:

[0081] S61. If C t is less than 0.8 times of C trig , and less than 1.2 times of C Land , and the time is greater than 30s, the UAV sends a low battery warning to the ground station, and the flight mode automatically switches to landing on the spot;

[0082] S62. If C t is less than C trig , and the time is greater than 30s, the UAV sends a low battery warning to the ground station, and the UAV mode automatically switches to the target landing point;

[0083] S63. If C t is less than 1.2 times of C trig , and the time is greater than 10s, the UAV only sends a low battery warning to the ground station.

[0084] S71. If the type of the original route landing point is the same as that of the target landing point, then determine whether the UAV has a descending and hovering point;

[0085] S72. If the type of the original route landing point is different from that of the target landing point, then determine the type of the target landing point.

[0086] S711. If the type of the original route landing point is the same as that of the target landing point, and the route includes a descending and hovering point, then the UAV directly flies to the descending and hovering point of the original route;

[0087] S712. If the type of the original flight route landing point is the same as that of the target landing point, but the flight route does not include a height reduction hovering point, then determine the type of the target landing point.

[0088] S7121. If the type of the original flight route landing point is the same as that of the target landing point, but the flight route does not include a height reduction hovering point, then determine the type of the target landing point. If it is a take-off point, the UAV flies towards the first waypoint of the flight route.

[0089] S7122. If the type of the original flight route landing point is the same as that of the target landing point, but the flight route does not include a height reduction hovering point, then determine the type of the target landing point. If it is an off-site landing point, the UAV flies towards the second last waypoint of the flight route.

[0090] S721. If the type of the original flight route landing point is different from that of the target landing point, and if the type of the target landing point is a take-off point, the UAV flies towards the first waypoint of the flight route.

[0091] S722. If the type of the original flight route landing point is different from that of the target landing point, and if the type of the target landing point is an off-site landing point, the UAV flies towards the second last waypoint of the flight route.

[0092] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A low - power autonomous landing decision - making method for a drone to take off and land at different locations, characterized in that, It includes the following steps: S1. Enter the low battery logic; S2. Calculate the straight-line distance L0 between the drone and the takeoff point; S3. Determine whether the drone mission route type is takeoff and landing in place; S4. Calculate the power required to return directly to the landing point from the current position; S5. Collect real-time power consumption C t ; S6. Switch the flight mode of the drone according to different power states; S7. After the drone triggers a return due to low battery, determine the type of the target landing point: S71. If the type of the original route landing point is the same as that of the target landing point, determine whether the drone has a descending and hovering point; S72. If the type of the original route landing point is different from that of the target landing point, determine the type of the target landing point.

2. The low-power autonomous landing decision-making method for off-site takeoff and landing of an unmanned aerial vehicle according to claim 1, wherein The determination of whether the drone mission route type is takeoff and landing in place includes the following steps: S31. If the drone mission route type is takeoff and landing in place, assign L0 to the landing measurement distance L; S32. If the drone mission route type is not takeoff and landing in place, calculate the straight-line distance L1 between the drone and the off-site landing point.

3. The low-power autonomous landing decision-making method for off-site takeoff and landing of an unmanned aerial vehicle according to claim 2, wherein The calculation of the straight-line distance L1 between the drone and the off-site landing point includes the following steps: S321. If L1 is less than 1.2 times L0, assign L1 to the landing measurement distance L and set the off-site landing point as the target landing point; S322. If L1 is greater than or equal to 1.2 times L0, assign L0 to the landing measurement distance L and set the takeoff point as the target landing point.

4. The low-power autonomous landing decision-making method for a drone to take off and land in different locations according to claim 1, characterized in that The calculation formula for the power required to return directly to the landing point from the current position is as follows: Input parameters: 1) Vertical / Landing Height: Set range H Land ; 2) Distance to the target landing point: L; 3) Wind speed: V Wind Positive in the direction towards the nose of the aircraft; 4) Descent speed: V Land ; 5) Return-to-home power set by the ground station: C Rest％ ; 6) Cruise airspeed: V Asp ; 7) Initial battery capacity: C0; 8) Landing current: I Land ; 9) Cruise current: I Cruise ; Calculation formula: 1) Vertical landing consumption capacity: 2) Capacity consumed by the fixed-wing to fly to the target landing point: 3) Remaining capacity to trigger return: C Trig = C Rest％ × C0 + C Land + C Distance .

5. A low-battery autonomous landing decision-making method for a drone to take off and land at different locations, characterized in that, The switching of the drone's flight mode according to different power states includes the following steps: S61. If C t is less than 0.8 times of C trig , and is less than 1.2 times of C Land , and the time is greater than 30 s, the UAV sends a low battery warning to the ground station, and the flight mode automatically switches to land on the spot; S62. If C t is less than C trig , and the time is greater than 30 s, the UAV sends a low - battery warning to the ground station, and the UAV mode automatically switches to the target landing point; S63. If C t is less than 1.2 times of C trig , and the time is greater than 10 s, the UAV only sends a low battery warning to the ground station.

6. The low-power autonomous landing decision-making method for off-site takeoff and landing of an unmanned aerial vehicle according to claim 1, characterized in that, When the type of the original route landing point is the same as that of the target landing point, the determination of whether the drone has a descending and hovering point includes the following steps: S711. If the type of the original route landing point is the same as that of the target landing point and the route includes a descending and hovering point, the drone directly flies to the descending and hovering point of the original route; S712. If the type of the original route landing point is the same as that of the target landing point, but the route does not include a descending and hovering point, determine the type of the target landing point.

7. The low-power autonomous landing decision-making method for off-site takeoff and landing of an unmanned aerial vehicle according to claim 6, characterized in that, When the type of the original route landing point is the same as that of the target landing point and the route does not include a descending and hovering point, the determination of the type of the target landing point includes the following steps: S7121. If the type of the original route landing point is the same as that of the target landing point, but the route does not include a descending and hovering point, determine the type of the target landing point. If it is the takeoff point, the drone flies to the first waypoint of the route; S7122. If the type of the original route landing point is the same as that of the target landing point, but the route does not include a descending and hovering point, determine the type of the target landing point. If it is the off-site landing point, the drone flies to the second-to-last waypoint of the route.

8. A low - power autonomous landing decision method for an unmanned aerial vehicle to take off and land at different locations according to claim 7, characterized in that, When the type of the original route landing point is different from that of the target landing point, the determination of the type of the target landing point includes the following steps: S721. If the type of the original route landing point is different from that of the target landing point, and if the type of the target landing point is the takeoff point, the drone flies to the first waypoint of the route; S722. If the type of the original flight route landing point is different from that of the target landing point, and if the type of the target landing point is an off-site landing point, the UAV flies towards the second-to-last waypoint of the route.

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