A charging control method for a drone system and a drone

Abstract

The application belongs to the technical field of unmanned aerial vehicle charging and relates to an unmanned aerial vehicle system and a charging control method of the unmanned aerial vehicle, so as to solve the problem of inconvenient or low flexibility of unmanned aerial vehicle charging. The system comprises a machine body, a battery, a landing gear, a foot frame contact plate and a parking apron. The machine body is provided with a cabin for accommodating the battery. A first positive charging wire, a first negative charging wire and a first switch-on-off wire are led out from the battery; the landing gear is arranged on the machine body; the foot frame contact plate is arranged on the landing gear, and a second positive charging wire, a second negative charging wire and a second switch-on-off wire are led out from the foot frame contact plate. The second positive charging wire is connected with the first positive charging wire, the second negative charging wire is connected with the first negative charging wire, and the second switch-on-off wire is connected with the first switch-on-off wire. The parking apron is provided with a nest contact plate, and the nest contact plate is in contact with the foot frame contact plate; the parking apron is provided with a charging management module, and an output end of the charging management module is electrically connected with the nest contact plate, so as to control the switch-on-off or charging of the battery.

Description

Technical Field

[0001] This invention belongs to the field of drone charging technology, and particularly relates to a drone system and a drone charging control method. Background Technology

[0002] Drone batteries are typically housed inside the drone's cabin, and are charged either via a cradle charger or through the drone's Type-C port. Both methods require removing the battery from the cabin and then replacing it after charging. This design presents technical challenges due to inconvenience and low flexibility in charging. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems of inconvenient or inflexible charging by proposing a drone system and a charging control method for drones.

[0004] In a first aspect, the present invention provides an unmanned aerial vehicle (UAV) system, comprising:

[0005] The fuselage, which contains an engine compartment;

[0006] The battery is housed in the cabin. A first positive charging wire, a first negative charging wire, and a first power-on / off wire are led out from the battery. The first positive charging wire, the first negative charging wire, and the first power-on / off wire pass through the cabin and are led out.

[0007] Landing gear, which is detachably mounted on the fuselage;

[0008] The landing gear has a landing gear contact plate, which is mounted on the landing gear. A second positive charging cable, a second negative charging cable, and a second power on / off cable are led out from the landing gear contact plate. The second positive charging cable is connected to the first positive charging cable, the second negative charging cable is connected to the first negative charging cable, and the second power on / off cable is connected to the first power on / off cable.

[0009] The helipad is equipped with a battery contact plate. During charging, the battery contact plate contacts the landing gear contact plate. The helipad is also equipped with a charging management module. The output of the charging management module is electrically connected to the battery contact plate and is used to control the battery's power-on, power-off, or charging.

[0010] As one possible implementation, the landing gear is a landing gear based on biomimetic and / or aerodynamic design.

[0011] As one possible implementation, the landing gear is a bird-like skeletal landing gear.

[0012] As one possible implementation, the landing gear includes: a mounting bracket for connecting to the fuselage, employing a ship keel-like weight-reducing structure; multiple support rods, which are inclined outwards and evenly installed around the mounting bracket; each support rod is a biomimetic low-drag, irregularly shaped, unequal-diameter, hollow structure; two landing gears, which are distributed opposite each other, each landing gear being connected to the bottom end of a support rod located on the same side of the mounting bracket; a landing gear contact plate is connected to the side of one of the landing gears; and reinforcing frames, each reinforcing frame being located between the two landing gears and connected to the bottom end of a support rod; each reinforcing frame is a low-drag, irregularly shaped, hollow structure.

[0013] As one possible implementation, the charging management module includes a power-on / off control circuit and a charging control circuit. The output of the power-on / off control circuit is connected to a second power-on / off line. The power-on / off control circuit receives power-on / off control timing signals to control the battery to power on or off. The power-on / off control timing signals include high-level and low-level signals transmitted in sequence. When the battery's initial state is off, the high-level signal is maintained for a first preset time and the low-level signal is maintained for a second preset time, at which point the battery powers on. When the battery's initial state is on and it needs to be changed to off, the high-level signal is maintained for a first preset time and the low-level signal is maintained for a second preset time, at which point the battery powers off.

[0014] The charging control circuit is connected to the second positive charging line and the negative charging line. The charging control circuit is equipped with a processor. The processor uses a constant frequency synchronous PWM controller to adjust the charging current of the battery so that the battery maintains a constant charging power before the charging voltage reaches the voltage threshold.

[0015] As one possible implementation, the charging control circuit includes:

[0016] The processor is configured with a constant power value, receives charging current feedback and charging voltage feedback, calculates and determines the measured power value based on the feedback charging current and charging voltage, compares the measured power value with the constant power value, and sets the charging current value based on the comparison result.

[0017] The charging current setting circuit is connected to the output terminal of the processor to set the control voltage of the charging current. It is also connected to the pin of the charging management chip to ensure that the actual value of the charging current of the charging management chip and the value of the charging current output by the processor are within a preset deviation range.

[0018] The charging management chip is connected to the output terminal of the charging current setting circuit. By controlling the voltage of the charging current pin of the charging management chip, the charging current can be controlled. The voltage of the charging current pin is the control voltage.

[0019] A synchronous rectifier switching circuit receives control signals from the charging management chip to control two power switching elements to be in the on and off states simultaneously. The two power switching elements are defined as a first power switching element and a second power switching element. When the first power switching element is on and the second power switching element is off, the battery is charged via direct charging. When the first power switching element is off and the second power switching element is on, the battery is charged via freewheeling charging.

[0020] The charging current feedback circuit is used to collect the measured current value at the output of the synchronous rectifier switch circuit and feed it back to the processor.

[0021] The charging voltage feedback circuit is used to collect the measured voltage value at the output of the synchronous rectifier switch circuit and feed it back to the processor.

[0022] The processor receives and determines the measured power value based on the measured current and voltage values. Based on the deviation between the measured power value and the preset power value, the processor adjusts the actual value of the charging current so that the battery maintains a constant charging power before the charging voltage reaches the voltage threshold.

[0023] As one possible implementation, a voltage threshold is configured in the processor, and when the measured voltage value is less than or equal to the voltage threshold, the actual value of the charging current is kept small so that the battery is in a constant power charging mode;

[0024] When the measured voltage value is greater than the voltage threshold, the measured voltage value is kept to increase slowly, and the actual value of the charging current is controlled to decrease, so that the battery is in trickle charging mode.

[0025] The voltage threshold is 16.8–17.2V.

[0026] Secondly, the present invention also provides a charging control method, comprising the following steps:

[0027] The drone landed on the helipad, and the tripod contact plate made electrical contact with the drone's nest contact plate.

[0028] The charging management module detects the battery's voltage status;

[0029] When the battery is in a state of low charge, the power-on / off control circuit controls the battery to turn on.

[0030] The synchronous rectifier switching circuit receives the charging control signal from the charging management chip to control the power switching element to turn on and charge the battery;

[0031] The charging current feedback circuit collects the measured current value at the output of the synchronous rectifier switch circuit and feeds it back to the processor.

[0032] The charging voltage feedback circuit collects the measured voltage value at the output of the synchronous rectifier switch circuit and feeds it back to the processor.

[0033] The processor receives and determines the measured power value based on the measured current value and the measured voltage value. Based on the deviation between the measured power value and the preset power value, it adjusts the actual value of the charging current so that the battery is in constant power charging mode when the charging voltage is less than or equal to the voltage threshold.

[0034] As one possible implementation, the synchronous rectifier switching circuit receives the processor's charging control signal to control the power switching elements to turn on and charge the battery, including the following steps:

[0035] The processor is configured with a voltage threshold. When the measured voltage value is less than or equal to the voltage threshold, the actual value of the charging current is kept small so that the battery is in a constant power charging mode.

[0036] When the measured voltage value is greater than the voltage threshold, the measured voltage value is kept to increase slowly, and the actual value of the charging current is controlled to decrease, so that the battery is in trickle charging mode.

[0037] Compared with the prior art, the present invention has the following technical effects:

[0038] 1. The charging method for drones has been changed from docking chargers or plug-and-play charging via Type-C interface to contact charging. The battery is located inside the drone bay, with a first positive charging cable, a first negative charging cable, and a first power-on / off cable leading out from the battery. These charging and power-on cables are then led out of the bay and electrically connected to a second positive charging cable, a second negative charging cable, and a second power-on / off cable extending from the landing gear contact plate. When the drone needs charging, there is no need to remove the battery from the bay or plug and unplug the charging and power-on cables. The landing gear contact plate and the drone's pod contact plate are directly controlled to make contact. A charging management module located on the landing pad and connected to the landing gear contact plate enables battery power-on / off and charging, offering advantages such as convenient charging and high flexibility.

[0039] 2. A charging current setting circuit (peripheral circuit) is configured with the charging current setting circuit. Specifically, an analog-to-digital conversion circuit is added to control the voltage value in the charging current setting circuit, thereby ensuring that the charging current is charged within the allowable deviation range of the set value, thus improving charging accuracy.

[0040] 3. A charging current feedback circuit and a charging voltage feedback circuit are added to the standard charging control circuit, and the measured current and voltage values ​​are fed back to the processor in real time. The processor adjusts the charging control signal based on the measured current and voltage values. Specifically, a voltage threshold is configured in the processor. When the measured voltage value is less than or equal to the voltage threshold, the measured current value is kept decreasing, and the measured voltage value is passively and continuously increasing, so that the battery maintains a constant charging power in the early stage of charging. When the measured voltage value is greater than the voltage threshold, the measured voltage value is kept increasing slowly, and the measured current value is controlled to decrease, so that the battery maintains a trickle charging mode in the later stage of charging. Attached Figure Description

[0041] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0042] Figure 1 This is a schematic diagram of the battery structure provided in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the landing gear contact plate provided in an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the structure of the contact plate provided in an embodiment of the present invention;

[0045] Figure 4 This is a schematic diagram of the landing gear structure according to an embodiment of the present invention;

[0046] Figure 5 A power-on / off control circuit diagram provided for an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of a charging management module provided in an embodiment of the present invention.

[0048] Figure label:

[0049] 1-Battery, 2-Landing gear, 3-Landing gear contact plate, 4-Landing pad, 5-Nest contact plate, 6-Charging management module;

[0050] 10-First positive charging cable, 11-First negative charging cable, 12-First power on / off cable;

[0051] 20-Mounting bracket, 21-Support frame, 22-Legged frame, 23-Reinforcing frame;

[0052] 30-Second positive lead wire, 31-Second negative lead wire, 32-Second power on / off wire, 33-Gold finger;

[0053] 50-Charging contacts;

[0054] 60-Power on / off control circuit; 61-Charging control circuit; 610-Charging management chip; 611-Charging current setting circuit; 612-Synchronous rectifier switch circuit; 613-Charging current feedback circuit; 614-Charging voltage feedback circuit; 615-Chip temperature monitoring circuit; 616-Charging status indicator light. Detailed Implementation

[0055] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0056] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0058] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0059] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0060] Firstly, see [the following] Figures 1 to 6 This invention provides an unmanned aerial vehicle (UAV) system, including an airframe (not shown in the figure), a battery 1, a landing gear 2, a landing gear contact plate 3, and a landing pad (not shown in the figure).

[0061] The above-described machine is a commercially available machine, and its structure will not be described in detail. The machine has a compartment for housing batteries (not shown in the figure).

[0062] The aforementioned battery 1 comprises a battery body and a casing. The battery body is a commercially available battery body, which has a VCC+ pin, a GND pin, and a power-on / power-off pin. In this embodiment of the invention, a first positive charging line 10 is led out from the VCC+ pin, a first negative charging line 11 is led out from the GND pin, and a first power-on / power-off line 12 is led out from the power-on / power-off pin. The charging line and the power-on / power-off line pass through the casing and are led out. The charging line and the power-on / power-off line converge and are connected to a female connector, which can pass through the engine compartment and be led out.

[0063] The landing gear 2 is a landing gear designed based on biomimicry and / or aerodynamics. The overall structure of the landing gear 2 is a bird-like skeletal landing gear, which may include a mounting bracket 20, multiple support rods 21, two legs 22 and two reinforcing frames 23.

[0064] The mounting bracket 20 can be detachably connected using any connection method provided by existing technology. For example, screw holes are pre-drilled on the bottom of the drone, and mounting holes are provided on the mounting bracket 20 to match these holes, allowing the bottom of the drone to be fixed to the mounting bracket 20 with screws. The mounting bracket 20 adopts a ship keel-like weight-reduction structure, meaning that the mounting bracket 20 has a long and narrow shape. This ship keel-like structure gives the long and narrow mounting bracket the advantages of being lightweight and not easily deformed. In other words, compared with the landing gear of the existing structure, it can achieve a lighter weight without reducing directional force-bearing capacity.

[0065] The elongated, narrow mounting bracket 20 has four corners, with support rods at the bottom of each corner angled outwards at equal angles. Each support rod is a biomimetic, low-drag, irregularly shaped, hollow structure with varying wall thicknesses and diameters. This design is more mechanically sound, effectively reducing weight and enhancing the drone's movement in a specific direction. Lower forces result in lower wind resistance. It should be further explained that the aforementioned "specific direction" refers to the drone's movement direction; lower forces in this direction lead to lower wind resistance. Furthermore, the use of a smaller frontal surface and lower drag cross-section design, compared to traditional, simpler landing gear configurations, results in more stable flight attitude and longer battery discharge time. It should be further explained that the smaller frontal surface and lower drag cross-section design can be referenced from the cross-sectional design and manufacturing of existing aircraft, which will not be elaborated upon here.

[0066] It should be further explained that the specific structure of one of the support rods 21 may differ from the other three support rods 21. Specifically, the bottom surface of one of the support rods 21 may be open to facilitate the internal routing of the second positive charging cable 50, the second negative charging cable 51, and the second power-on / off cable 52. The aforementioned charging cables and power-on / off cables are led out from the bottom of the mounting bracket, and clips are engaged along the edge of the mounting bracket to secure them to the bottom of the mounting bracket.

[0067] Two legs 22 are distributed opposite each other, and each leg 22 is connected to the bottom end of the support rod 21 located on the same side of the mounting bracket 20. The side of one of the legs 22 is connected to the leg contact plate 3.

[0068] As an example, in the assembled state, the landing gear contact plate 3 is perpendicular to the horizontal plane. Correspondingly, the helipad contact plate 5 on the apron is also perpendicular to the horizontal plane. This ensures sufficient and tight contact between the landing gear contact plate and the helipad contact plate, and also has the advantage of simple structure. Of course, the landing gear contact plate 3 can also be at an angle to the horizontal plane, and correspondingly, the helipad contact plate 5 on the apron can also be at an angle to the horizontal plane, with both angles being equal.

[0069] Each reinforcing frame 23 is located between two legs 22 and connected to the bottom end of the support rod 21; each reinforcing frame 23 is a low-wind-resistance irregular hollow structure.

[0070] Landing gear 2 can be made of high-strength, lightweight materials, ensuring both lightness and sufficient strength. As an example, the materials used could be ABS-CF, PA-CF, PETG-CF, or three types of carbon fiber-containing materials.

[0071] The landing gear contact plate 3 is mounted on the landing gear 2. A second positive charging cable 50, a second negative charging cable 51, and a second power-on / off cable 52 are led out from the landing gear contact plate 3. The second positive charging cable 50 is connected to the first positive charging cable 10, the second negative charging cable 51 is connected to the first negative charging cable 11, and the second power-on / off cable 52 is connected to the first power-on / off cable 12. The charging cables and power-on / off cable converge and connect to a male connector. In practical applications, the male connector is mated with the female connector to achieve electrical connection between the battery and the landing gear contact plate.

[0072] The tripod contact plate 3 is equipped with charging gold fingers, with a contact current greater than 15A. It should be further explained that the charging gold fingers on existing tripod contact plates typically have a contact current of 8A, while the charging gold fingers provided in this invention have a design area far exceeding the 8A requirement. Specifically, FR4 copper foil is used, and the copper plating process has a thickness of 2 ounces and 120 mils to increase the contact current.

[0073] By adopting the above technical solution, the charging method of the drone is changed from docking charger or plug-and-play charging via Type-C interface to contact charging. Specifically, battery 1 is located inside the drone cabin, and a first positive charging cable 10, a first negative charging cable 11, and a first power-on / off cable 12 are led out from battery 1. These charging and power-on / off cables are further led out of the drone cabin and electrically connected to a second positive charging cable 50, a second negative charging cable 51, and a second power-on / off cable 52 led out from the landing gear contact plate. When the drone needs charging, there is no need to remove battery 1 from the drone cabin, nor is it necessary to plug or unplug the charging and power-on / off cables. The landing gear contact plate 3 and the drone's nest contact plate 5 are directly controlled. The charging management module, located on the landing pad and connected to the landing gear contact plate 3, enables the battery to be powered on / off and charged. This method offers the advantages of convenient charging and high flexibility.

[0074] A battery contact plate 5 is installed on the helipad. When charging, the battery contact plate 5 is in contact with the landing gear contact plate 3. A charging management module is also installed on the helipad. The output of the charging management module is electrically connected to the battery contact plate 5 to control the battery's power-on, power-off or charging.

[0075] The helipad is equipped with a motor-driven push rod. After the drone lands on the helipad, the motor drives the push rod, which in turn pushes the landing gear, causing the drone to automatically move to the predetermined charging position.

[0076] After the drone lands on the hangar, the push rod motor drives the up and down and left and right push rods to push the drone to the center of the hangar using mechanical force. At this time, the hangar end contact plate 5 makes close contact with the drone's landing gear gold fingers through the contact points to complete the connection between the drone battery and the charging management unit. After the charging management module detects the position sensor's arrival prompt and can detect the battery voltage, it executes the predetermined logic according to the battery's power level, either charging or shutting down.

[0077] The charging management module includes a power-on / off control circuit 60 and a charging control circuit 61. The output of the power-on / off control circuit 60 is connected to the second power-on / off line 32. The power-on / off control circuit 60 receives power-on / off control timing signals to control the battery 1 to power on or off. The power-on / off control timing signals include high-level and low-level signals transmitted in a sequential sequence. When the high-level signal is maintained for a first preset time and the low-level signal is maintained for a second preset time, the battery 1 is powered on; when the high-level signal is maintained for the first preset time and the low-level signal is maintained for the second preset time, the battery 1 is powered off.

[0078] Further explanation is needed regarding the drone system's configuration. The drone system is equipped with a processor (specifically, an ARM processor), which sets a battery temperature threshold. When the drone lands on the helipad and actively or passively moves / adjusts to the charging position, the landing gear contact plate 3 and the nacelle contact plate 5 make electrical contact. The system then checks for voltage. If voltage is present, it indicates that battery 1 is powered on. Based on this, the processor further reads the battery 1's temperature. If the measured temperature of battery 1 is lower than the aforementioned threshold, charging is allowed. If the battery temperature is greater than or equal to the threshold, the air conditioning is activated to cool it down until the temperature falls below the threshold before charging is permitted. If no voltage is detected, it indicates that battery 1 is powered off. At this point, a power-on sequence is executed to turn battery 1 from powered off to powered on. Afterward, the battery temperature is further monitored, and the relationship between the battery temperature and the threshold is determined. Based on the above determination, charging or cooling is then performed.

[0079] The charging control circuit 61 is connected to the second positive charging line 30 and the second negative charging line 31. The charging control circuit 61 is equipped with a processor. The processor uses a constant frequency synchronous PWM controller to adjust the charging current of the battery 1 so that the battery 1 maintains a constant charging power before the charging voltage reaches the voltage threshold.

[0080] As one possible implementation, the charging control circuit includes: a processor configured with constant power, receiving charging current feedback and charging voltage feedback, calculating and determining the measured power value based on the feedback charging current and charging voltage, comparing the measured power value with the constant power value, and setting the charging current value based on the comparison result.

[0081] The charging management chip 610 is connected to the output of the charging current setting circuit. By controlling the voltage on the charging current pin of the charging management chip, the charging current is controlled; this voltage serves as the control voltage. As an example, the charging management chip 610 can be the BQ24640 chip manufactured by TI. This chip is a highly integrated switch-mode supercapacitor charging controller that provides high-accuracy charging current regulation using constant-frequency synchronous PWM control and can monitor and protect the charging status. Constant power control typically provides a certain amount of power to the battery within a specific time frame for fast and efficient charging. Safety protection functions are implemented internally by the BQ24640 chip, firstly monitoring and protecting the charging status. It provides charging voltage regulation, charging current regulation, internal loop compensation, internal digital soft start, input overvoltage protection, capacitor temperature sensing for hot / cold charging pause, and thermal shutdown.

[0082] The BQ24640 chip has a CE enable pin, which receives an enable signal. When it receives a high-level signal (1), the BQ24640 chip allows charging, meaning it can accept feedback signals and send control signals. When it receives a low-level signal (0), the BQ24640 chip terminates charging.

[0083] The charging current setting circuit 611, connected to the processor's output, is used to set the control voltage for the charging current. It is also connected to the pins of the charging management chip 610, ensuring that the actual value of the charging current from the charging management chip 610 is within a preset deviation range from the charging current output by the processor. Further explanation is needed: the charging current setting circuit 611 controls the voltage at pin 7 of the charging management chip 610 via analog-to-digital conversion to meet the setting / adjustment requirements of the charging current. Specifically, it may include an analog-to-digital converter chip (specifically, a TPL0501) and peripheral circuitry. The analog-to-digital converter chip ensures that the voltage applied to pin 7 meets a preset voltage range, such as not exceeding 2V. In specific applications, the processor is connected to pins 4, 5, and 6 of the analog-to-digital converter chip. In practical applications, the charging current can be changed by continuously adjusting the voltage at pin 7 of the charging management chip 610 to achieve constant power charging. The voltage is a passive value; that is, as charging continues, the voltage increases initially, and then decreases continuously during the process to maintain constant power charging. When the charging voltage increases to a threshold, such as 16.8V, the measured voltage will slowly increase while the charging current continuously decreases (at this point, the charging current is several hundred to tens of milliamps) to switch the charging mode to trickle charging mode. When the charging voltage continues to increase, i.e., exceeds 17.5V, the battery will switch to sleep mode.

[0084] The synchronous rectifier switch circuit 612 receives control signals from the charging management chip 610 to control two power switching elements to be in an on / off state simultaneously. These two power switching elements are defined as the first power switching element and the second power switching element. When the first power switching element is on and the second power switching element is off, the battery is charged via direct charging. When the first power switching element is off and the second power switching element is on, the battery is charged via freewheeling charging. In practical applications, the synchronous rectifier switch circuit 612 may specifically include a 24V power supply, diode D2, power switching elements Q1 and Q2, bootstrap diode D3, freewheeling inductor L2, and peripheral circuitry (for energy storage or filtering). D2 ensures that the 24V voltage can be input to the drain of Q1. It should be understood that even without D2 in the synchronous rectifier switch circuit, the 24V voltage can still be input to the drain of Q1, but there is a risk that the charging voltage after the freewheeling inductor L2 will return through Q1, potentially causing energy loss.

[0085] In practical applications, Q1 is on and Q2 is off, L2 stores energy and charges the load; this charging mode can be defined as direct charging mode. When Q1 is off and Q2 is on, the energy in L2 can flow back to L2 through the battery via Q2, allowing L2 to perform freewheeling charging. D3 is a bootstrap diode. When both power switching elements are MOSFETs, Q1 needs a bootstrap circuit to meet the turn-on condition, i.e., the voltage at gate (G) needs to be greater than the voltage at source (S) to meet the turn-on condition.

[0086] The charging current feedback circuit 613 is used to collect the measured current value at the output terminal of the synchronous rectifier switch circuit 612 and feed it back to the processor.

[0087] The charging voltage feedback circuit 614 is used to acquire the measured voltage value at the output terminal of the synchronous rectifier switch circuit 612 and feed it back to the processor. In practical applications, the difference between this embodiment and the prior art lies in the resistance value of the feedback resistor in the charging voltage feedback circuit 614. Since the processor is equipped with an analog-to-digital converter circuit, it needs to have a certain input voltage range, and the charging voltage cannot exceed the processor's operating voltage. Therefore, the feedback voltage needs to be controlled by setting the resistance value.

[0088] The processor receives and determines the measured power value based on the measured current value and the measured voltage value. Based on the deviation between the measured power value and the preset power value, it adjusts the actual value of the charging current so that the battery maintains a constant charging power before the charging voltage reaches the voltage threshold.

[0089] As one possible implementation, the charging control circuit also includes a chip temperature monitoring circuit 615, which is connected to the processor's pins to monitor the temperature of the BQ24640 chip. When the temperature is detected to be too high, the power switching element will be cut off.

[0090] As one possible implementation, the charging control circuit 61 also includes a charging status indicator 616, which is connected to the pin of the charging current setting circuit 611 and is used to display the charging status.

[0091] As one possible implementation, the processor is configured with a voltage threshold. When the measured voltage value is less than or equal to the voltage threshold, the charging voltage is increased and the charging current is decreased so that the battery is in a constant power supply mode.

[0092] When the measured voltage value is greater than the voltage threshold, the measured voltage value is kept to increase slowly, and the measured current value is controlled to decrease, so that the battery is in trickle charging mode.

[0093] During the initial stage of battery charging, a constant power supply is used. When the voltage reaches 17.2V, it switches to trickle charging, using a small current of tens to hundreds of milliamps. The charging voltage feedback circuit 614 is set to 17.5V. When the charging voltage exceeds 17.5V, it enters sleep mode, and the charging current is less than that during trickle charging, at the microamp level, at which point charging ends.

[0094] As an example, the voltage threshold is 16.8V to 17.2V.

[0095] Compared with existing technologies, the charging current setting circuit (peripheral circuit) is configured with a charging current setting circuit, specifically by adding an analog-to-digital conversion circuit to control the voltage value in the charging current setting circuit. This ensures that the charging current is charged within the allowable deviation range of the set value, thereby improving charging accuracy.

[0096] A charging current feedback circuit and a charging voltage feedback circuit are added to the standard charging control circuit, and the measured current and voltage values ​​are fed back to the processor in real time. The processor adjusts the charging control signal based on the measured current and voltage values. Specifically, a voltage threshold is configured in the processor. When the measured voltage value is less than or equal to the voltage threshold, the measured current value is kept decreasing and the measured voltage value is kept increasing, so that the battery maintains a constant charging power in the early stage of charging. When the measured voltage value is greater than the voltage threshold, the measured voltage value is kept increasing slowly and the measured current value is controlled to decrease, so that the battery maintains a trickle charging mode in the later stage of charging.

[0097] Secondly, embodiments of the present invention also provide a charging control method, comprising the following steps:

[0098] The drone landed on the helipad, and the tripod contact plate made electrical contact with the drone's nest contact plate.

[0099] The charging management module detects the battery's voltage status;

[0100] When the battery is in a depleted state, the power-on / off control circuit controls the battery to turn on.

[0101] The synchronous rectifier switch circuit receives the charging control signal from the charging current setting circuit to control the power switch element to turn on and charge the battery.

[0102] The charging current feedback circuit collects the measured current value at the output terminal of the synchronous rectifier switch circuit and feeds it back to the processor.

[0103] The charging voltage feedback circuit collects the measured voltage value at the output terminal of the synchronous rectifier switch circuit and feeds it back to the processor;

[0104] The processor receives and determines the measured power value based on the measured current value and the measured voltage value. Based on the deviation between the measured power value and the preset power value, it adjusts the actual value of the charging current so that the battery is in constant power charging mode when the charging voltage is less than or equal to the voltage threshold.

[0105] As one possible implementation, the synchronous rectifier switch circuit receives a charging control signal from the charging current setting circuit to control the power switching element to turn on and charge the battery, including the following steps:

[0106] The processor is configured with a voltage threshold. When the measured voltage value is less than or equal to the voltage threshold, the charging voltage is increased and the charging current is decreased so that the battery is in a constant power supply mode.

[0107] When the measured voltage value is greater than the voltage threshold, the measured voltage value is kept to increase slowly, and the measured current value is controlled to decrease, so that the battery is in trickle charging mode.

[0108] Those skilled in the art will understand from the foregoing description that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes, but is not limited to, various media capable of storing program code, such as USB flash drives, portable hard drives, magnetic storage devices, and optical storage devices.

[0109] As can be seen from the foregoing description, embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. The above descriptions are merely preferred embodiments of the present invention, and the present invention should not be limited to the content disclosed in these embodiments and drawings. All equivalents or modifications made without departing from the spirit of the present invention fall within the scope of protection of the present invention.

[0110] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0111] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An unmanned aerial vehicle (UAV) system, characterized in that, include: The fuselage, on which an engine compartment is provided; A battery is housed in the cabin, and a first positive charging cable, a first negative charging cable, and a first power-on / off cable are led out from the battery. The first positive charging cable, the first negative charging cable, and the first power-on / off cable pass through the cabin and are led out. Landing gear, which is detachably mounted on the fuselage; A landing gear contact plate is provided on the landing gear. A second positive charging cable, a second negative charging cable, and a second power on / off cable are led out from the landing gear contact plate. The second positive charging cable is connected to the first positive charging cable, the second negative charging cable is connected to the first negative charging cable, and the second power on / off cable is connected to the first power on / off cable. The helipad is equipped with a battery contact plate, which contacts the landing gear contact plate during charging. The helipad is also equipped with a charging management module, the output of which is electrically connected to the battery contact plate to control the battery's power-on, power-off, or charging. The charging management module includes a power-on / off control circuit and a charging control circuit. The output of the power-on / off control circuit is connected to the second power-on / off line. The power-on / off control circuit receives power-on / off control timing signals to control the battery to power on or off. The power-on / off control timing signals include high-level and low-level signals transmitted in sequence. When the battery's initial state is off, the battery powers on when the high-level signal is maintained for a first preset time and the low-level signal is maintained for a second preset time. When the battery's initial state is on and it needs to be changed to off, the battery powers off when the high-level signal is maintained for a first preset time and the low-level signal is maintained for a second preset time. The charging control circuit is connected to the second positive charging line and the negative charging line. The charging control circuit is equipped with a processor. The processor uses a constant frequency synchronous PWM controller to adjust the charging current of the battery so that the battery maintains a constant charging power before the charging voltage reaches the voltage threshold.

2. The unmanned aerial vehicle system according to claim 1, characterized in that, The landing gear is a landing gear designed based on bionics and / or aerodynamics.

3. The unmanned aerial vehicle system according to claim 2, characterized in that, The landing gear is designed to resemble bird skeletons.

4. The unmanned aerial vehicle system according to claim 2, characterized in that, The landing gear includes: Mounting bracket, which is used to connect the body, adopts a ship keel-type weight-reducing structure; Multiple support rods are installed outwardly and evenly around the mounting bracket; each support rod is a biomimetic low-resistance irregular-shaped hollow structure with unequal wall thickness and different diameter. Two legs are arranged opposite each other, and each leg is connected to the bottom end of the support rod located on the same side of the mounting bracket; the side of one of the legs is connected to the leg contact plate; And a reinforcing frame, each of which is located between the two legs and connected to the bottom end of the support rod; each of the reinforcing frames is a low-wind-resistance irregular hollow structure.

5. The unmanned aerial vehicle system according to claim 1, characterized in that, The charging control circuit includes: The processor is configured with a constant power value, receives charging current feedback and charging voltage feedback, calculates and determines the measured power value based on the feedback charging current and charging voltage, compares the measured power value with the constant power value, and sets the charging current value based on the comparison result. The charging current setting circuit is connected to the output terminal of the processor and is used to set the control voltage of the charging current. It is also connected to the pin of the charging management chip so that the actual value of the charging current of the charging management chip and the value of the charging current output by the processor are within a preset deviation range. A charging management chip is connected to the output terminal of a charging current setting circuit. By controlling the voltage of the charging current pin of the charging management chip, the charging current can be controlled. The charging current pin voltage is the control voltage. The synchronous rectifier switch circuit receives control signals from the charging management chip to control two power switching elements to be in the on and off states at the same time. The two power switching elements are defined as the first power switching element and the second power switching element, respectively. When the first power switching element is on and the second power switching element is off, the battery is charged in a direct charging manner. When the first power switching element is off and the second power switching element is on, the battery is charged in a freewheeling charging manner. A charging current feedback circuit is used to collect the measured current value at the output terminal of the synchronous rectifier switch circuit and feed it back to the processor. A charging voltage feedback circuit is used to collect the measured voltage value at the output terminal of the synchronous rectifier switch circuit and feed it back to the processor. The processor receives and determines the measured power value based on the measured current value and the measured voltage value. Based on the deviation between the measured power value and the preset power value, the processor adjusts the actual value of the charging current so that the battery maintains a constant charging power before the charging voltage reaches the voltage threshold.

6. The unmanned aerial vehicle system according to claim 5, characterized in that, The processor is configured with a voltage threshold. When the measured voltage value is less than or equal to the voltage threshold, the actual value of the charging current is kept small so that the battery is in a constant power charging mode. When the measured voltage value is greater than the voltage threshold, the measured voltage value is kept to increase slowly, and the measured current value is controlled to decrease, so that the battery is in trickle charging mode.

7. The unmanned aerial vehicle system according to claim 6, characterized in that, The voltage threshold is 16.8–17.2V.

8. The charging control method for an unmanned aerial vehicle system according to claim 5, characterized in that, Includes the following steps: The drone landed on the helipad, and the tripod contact plate made electrical contact with the drone's nest contact plate. The charging management module detects the battery's voltage status; When the battery is in a depleted state, the power-on / off control circuit controls the battery to turn on. The synchronous rectifier switch circuit receives the charging control signal from the charging management chip to control the power switching element to turn on and charge the battery; The charging current feedback circuit collects the measured current value at the output terminal of the synchronous rectifier switch circuit and feeds it back to the processor. The charging voltage feedback circuit collects the measured voltage value at the output terminal of the synchronous rectifier switch circuit and feeds it back to the processor; The processor receives and determines the measured power value based on the measured current value and the measured voltage value. Based on the deviation between the measured power value and the preset power value, it adjusts the actual value of the charging current so that the battery is in constant power charging mode when the charging voltage is less than or equal to the voltage threshold.

9. The charging control method according to claim 8, characterized in that, The synchronous rectifier switching circuit receives the processor's charging control signal to control the power switching element to turn on and charge the battery, including the following steps: The processor is configured with a voltage threshold. When the measured voltage value is less than or equal to the voltage threshold, the charging voltage is increased and the charging current is decreased so that the battery is in a constant power supply mode. When the measured voltage value is greater than the voltage threshold, the measured voltage value is kept to increase slowly, and the measured current value is controlled to decrease, so that the battery is in trickle charging mode.

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