A tilting mechanism for tilting a hexacopter unmanned aerial vehicle and a control method thereof

Abstract

This invention discloses a tilting mechanism and its control method for a tilting hexacopter unmanned aerial vehicle (UAV), belonging to the field of UAV technology. The tilting mechanism includes an arm, a support frame, a motor backplate, a drive assembly, and a limiting assembly. The drive assembly consists of a servo motor, a servo arm, a lead screw, and a fisheye connector connected in sequence, with the fisheye connector hinged to the motor backplate. The rotational motion output by the servo motor is converted into linear displacement by the drive assembly, driving the motor backplate to tilt between a vertical and horizontal working position around the main rotation axis. A vertical and horizontal limiter are provided on the support frame to abut against the motor backplate and limit the rotation boundary. The control method includes: receiving a mode switching command to determine the target tilt angle; performing amplitude limiting and error compensation on the target tilt angle to obtain the executed tilt angle; decomposing the executed tilt angle into multiple step increments, outputting PWM signals at set time intervals to drive the servo motor, causing the motor backplate to gradually approach the target tilt angle; and deduplicating repeated commands in each control cycle. This invention has a simple structure, clear working boundaries, stable and high-precision control, and can effectively avoid mechanical shock and overtravel risks.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) technology, specifically relating to a tilting mechanism and its control method for a tilting hexacopter UAV. Background Technology

[0002] Tiltrotor drones combine the advantages of both multi-rotor and fixed-wing drones. When the tilt mechanism is in a vertical position, the drone can perform vertical takeoff and landing, hovering, and low-speed maneuvering, requiring minimal landing sites. When the tilt mechanism is tilted to a horizontal position, the wings bear the main lift, reducing overall cruise drag and energy consumption, and improving flight speed, range, and endurance. Furthermore, they are adaptable to multiple scenarios, covering diverse missions such as military delivery, medical rescue, maritime patrol, and urban air traffic control, effectively reducing reliance on dedicated airport runways and becoming a key supporting equipment for the development of the low-altitude economy. However, existing tilt mechanisms generally suffer from the following problems:

[0003] First, the structure is complex. Many solutions use gearboxes, multi-stage connecting rods, or a large number of intermediate transmission components, resulting in a long transmission chain, high precision requirements for parts, and increased weight and cost of the whole machine.

[0004] Second, the mechanical boundaries are unclear. The lack of reliable mechanical limit design makes it prone to wobbling or position drift after tilting into place, resulting in poor repeatability.

[0005] Third, the control method is crude. Common control methods directly jump to the target angle without considering transmission inertia, backlash, and limits, which can easily cause servo motor shock, sudden attitude changes, rudder jitter, and overtravel damage.

[0006] Therefore, there is an urgent need for a tilting mechanism with a simplified structure, clear boundaries, and smooth control, as well as its supporting control method. Summary of the Invention

[0007] Therefore, the purpose of this invention is to provide a tilting mechanism and its control method for a tilting hexacopter unmanned aerial vehicle, so as to solve the problems of long transmission chain, inaccurate positioning, large impact and easy overtravel in the prior art.

[0008] The technical solution provided by this invention is: a tilting mechanism for a tilting hexacopter unmanned aerial vehicle, comprising:

[0009] The arm is used to connect to the drone body;

[0010] A support frame is fixedly mounted on the arm;

[0011] The motor backplate is rotatably mounted on the support frame via the main rotating shaft and is used to support the power motor;

[0012] A drive assembly, mounted on the support frame, includes a servo motor, a servo arm, a lead screw, and a fisheye connector that are sequentially connected in transmission. The fisheye connector is hinged to the motor backplate.

[0013] The rotational motion output by the servo motor is converted into linear displacement through the servo arm, lead screw and fisheye connector, which pushes the motor back plate to tilt between the vertical working position and the horizontal working position around the main rotation axis;

[0014] The support frame is also provided with a vertical limiter and a horizontal limiter, which are used to abut against the motor back plate at the vertical working position and the horizontal working position, respectively.

[0015] Preferably, the support frame includes two side plates arranged opposite each other and a support rod connecting the two side plates, and the two ends of the main rotation shaft are respectively mounted on the two side plates.

[0016] Preferably, the vertical working position corresponds to a tilt angle of 0° with respect to the motor back plate, and the horizontal working position corresponds to a tilt angle of 90°.

[0017] The present invention also provides a method for controlling the above-mentioned tilting mechanism, comprising:

[0018] Receive mode switching instructions and determine the target tilt angle;

[0019] The target tilt angle is subjected to amplitude limiting and error compensation to obtain the execution tilt angle;

[0020] The target tilt angle is limited to ensure that it does not exceed the mechanical range defined by the vertical and horizontal working positions.

[0021] The tilt angle is decomposed into multiple step increments, and the corresponding PWM signals are output sequentially according to the set time interval to drive the servo motor, so that the motor backplate gradually approaches the target tilt angle;

[0022] In each control cycle, if the difference between the current PWM signal to be output and the PWM signal output in the previous cycle is less than a preset threshold, the output of the previous cycle will remain unchanged.

[0023] Preferably, the limiting processing and error compensation specifically include: limiting the initial target tilt angle for the first time so that it falls within the mechanically permissible range;

[0024] Error compensation is performed on the tilt angle after the first amplitude limiting to eliminate the angle deviation caused by transmission clearance and installation error;

[0025] The compensated tilt angle is then subjected to a second limit to obtain the final executed tilt angle.

[0026] Preferably, the magnitude of the step increment and the time interval are preset according to the servo motor response characteristics and the inertia of the tilting mechanism, so that there is no mechanical impact during the tilting process.

[0027] Preferably, the method further includes: converting the final tilt angle and the servo control angle according to a linear mapping relationship, wherein the two ends of the linear mapping relationship correspond to the lower limit and the upper limit of the servo control angle, respectively.

[0028] Preferably, the difference is an angular difference, and the preset threshold is greater than 0.

[0029] The tilting mechanism provided by this invention has fewer transmission stages, fewer intermediate links, and a clear transmission path. The vertical and horizontal working positions are directly defined by mechanical limits, resulting in clear working boundaries. The control algorithm is designed directly to address the physical limits and transmission clearances of the mechanism. It achieves tilting using a direct transmission link consisting of a servo motor, servo arm, lead screw, fisheye connector, and motor backplate. The working boundaries of the mechanism are defined by vertical and horizontal limit components. Simultaneously, the control algorithm performs smooth stepping, dual limiting, command deduplication, and error compensation processing on the tilt angle command, thereby achieving stable and precise tilting control.

[0030] Compared with the prior art, the present invention also has the following beneficial effects:

[0031] This invention effectively simplifies the transmission chain of the tilting mechanism, overcomes the shortcomings of the prior art such as long transmission chains, complex structures, and high weight and cost, and significantly improves the simplification and ease of implementation of the mechanism.

[0032] This invention, through the main rotation axis in conjunction with vertical and horizontal limiting components, clarifies the mechanical working range of the mechanism, solves the problems of unclear working boundaries and poor repeatability of tilting into place in existing structures, and effectively improves positioning consistency.

[0033] This invention employs a smooth step control method, which avoids the servo motor shock and attitude change caused by direct angle jumps in traditional control, making the tilting process smoother and reducing mechanical shock.

[0034] This invention avoids servo motor jitter caused by repeated control commands through a command deduplication mechanism, and at the same time introduces error compensation to eliminate angular deviation caused by transmission backlash, thereby improving the stability of servo motor control and the accuracy of tilt angle control.

[0035] This invention combines software limiting with mechanical limiting to form dual protection, effectively preventing the target angle from exceeding physical limits and reducing the risk of over-range movement and damage to the mechanism. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is an external overall schematic diagram of the tilting mechanism of the present invention when it is installed on the machine arm.

[0039] Figure 2 for Figure 1 The cross-sectional view of the tilting mechanism shown illustrates the internal transmission structure and limiting components.

[0040] Figure 3 This is the main program flowchart of the control method of the present invention.

[0041] Figure 4 The flowchart for the smooth step subroutine.

[0042] Figure 5 The flowchart is for the dual-angle limit and illegal value correction subroutine.

[0043] Figure 6 Flowchart of the subroutine for deduplication of PWM commands and compensation for angle output error. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0045] The present invention provides a tilting mechanism for a tilting hexacopter unmanned aerial vehicle, comprising:

[0046] One end of the arm 3 is fixedly connected to the UAV body, and the other end is used to install the tilting mechanism. The side plate 20 and the support rod 22 together form the support frame of the tilting mechanism. This frame is fixed to the arm 3 to improve the structural stability and deformation resistance of the tilting mechanism during the tilting process.

[0047] The two ends of the main rotating shaft 14 are fixedly mounted on the two side plates 20, and the motor back plate 5 is rotatably mounted on the main rotating shaft 14 through bearings. The main rotating shaft 14 serves as the rotation center of the motor back plate 5, defining its rotation axis, so that the motor back plate 5 can rotate stably around the main rotating shaft 14 within a predetermined angle range.

[0048] The drive assembly includes a servo motor 1, a servo arm 2, a lead screw 4, and a fisheye connector 13. The servo motor 1 is fixed to the support frame and provides the rotational input required for tilting motion. The servo arm 2 is connected to the output end of the servo motor 1 and transmits the motion of the servo motor 1 to the lead screw 4. The lead screw 4, as the main force transmission component, undergoes displacement changes under the drive of the servo arm 2. The fisheye connector 13 is located between the lead screw 4 and the motor backplate 5, with one end connected to the lead screw 4 and the other end hinged to the motor backplate 5. It can adapt to the angular deviation between the lead screw and the motor backplate caused by attitude changes, ensuring a continuous and stable force transmission process.

[0049] The motor backplate 5 serves as the mounting base for the motor. Under the coordinated action of the servo motor 1, servo arm 2, lead screw 4, and fisheye connector 13, it rotates around the main rotation axis 14, thereby driving the motor mounted on the motor backplate 5 to rotate synchronously. Thus, the internal mechanism forms a power transmission path of servo motor 1 → servo arm 2 → lead screw 4 → fisheye connector 13 → motor backplate 5, without intermediate gears or multi-stage linkages, resulting in a simple structure and direct transmission. This path is used to convert the control actions output by the servo motor into the tilting motion of the motor backplate, achieving a continuous conversion of the power direction from vertical take-off and landing to horizontal cruising, or vice versa.

[0050] The limiting components include a vertical limiter 15 and a horizontal limiter 16, which are respectively mounted on the support frame. The vertical limiter 15 limits the motor backplate 5 to the position of 0° corresponding to the vertical take-off and landing mode, ensuring the required attitude of the motor during vertical take-off and landing or hovering conditions. The horizontal limiter 16 limits the motor backplate 5 to the position of 90° corresponding to the horizontal cruise mode, ensuring the required attitude of the motor during high-speed cruise conditions. Together, they limit the rotation range of the motor backplate 5 around the main rotation axis 14 to 0 to 90°, thereby preventing over-range rotation and improving the certainty of the attitude boundaries.

[0051] The tilting mechanism works as follows: After the output shaft of servo motor 1 rotates, servo arm 2 drives lead screw 4 to move. Lead screw 4 pushes motor backplate 5 to rotate around main rotation axis 14 through fisheye connector 13, thereby causing the motor to tilt between vertical take-off and landing attitude and cruise attitude. Vertical limiter 15 is used to limit motor backplate to the vertical working position, and horizontal limiter 16 is used to limit motor backplate to the horizontal working position.

[0052] This invention reduces the use of multi-stage transmission components and additional connecting parts, thereby reducing the number of parts and the complexity of processing and assembly. Compared with existing solutions with longer transmission chains and more parts, this invention is more advantageous in controlling the weight of the mechanism and manufacturing costs, and is suitable for tilt-rotor UAVs that are sensitive to weight and space constraints.

[0053] This invention defines the rotation axis by using a main rotation shaft and directly defines two boundary working positions by using vertical and horizontal limiters, giving the vertical and horizontal positions of the motor backplate clear mechanical references. Compared with existing solutions that rely solely on control programs to set boundaries or have unclear boundary definitions, this invention improves the certainty of the tilt endpoint position and the consistency of repeated positioning, reducing the problem of endpoint offset after multiple actions.

[0054] In addition, this invention also provides a control method for controlling the output process of the servo motor 1, enabling the motor base 5 to tilt within a set range of 0° to 90° according to a predetermined pattern. The control algorithm includes smooth step control, dual limit control, PWM command deduplication, and angle output error compensation. Smooth step control decomposes the target tilt angle into multiple consecutive small step amounts to reduce abrupt angle changes and mechanical shocks during the tilting process of the motor base 5. Dual limit control establishes a correspondence between the software control boundary and the mechanical limit boundary to prevent the target angle from exceeding the allowable range of the mechanism. PWM command deduplication avoids the main control program from continuously sending repetitive control values, which could cause the servo motor 1 to jitter. Angle output error compensation corrects the deviation in the final tilt angle caused by transmission gaps and installation errors in the lead screw 4, fisheye connector 13, and related transmission links.

[0055] During operation, the control system outputs corresponding control signals to servo motor 1 according to the flight mode switching command. After servo motor 1 outputs rotational motion, it is transmitted to motor base 5 via servo arm 2, lead screw 4, and fisheye connector 13, driving motor base 5 to rotate around main rotation axis 14. When motor base 5 rotates to the corresponding boundary position, boundary constraints are completed by vertical limiter 15 or horizontal limiter 16. Through the cooperation of structure and control algorithm, this invention can realize stable switching of motor between vertical take-off and landing attitude and horizontal cruise attitude, and meet the requirements of angle control, boundary constraints, and operational smoothness during tilting.

[0056] The specific mathematical description is as follows.

[0057] Let the tilt angle of the motor backplate 5 relative to the vertical working position be . ,in Indicates the vertical work position. Indicates the horizontal working position. The working angle range of the mechanism satisfies:

[0058] (1)

[0059] in, , .

[0060] Let the external input reference tilt angle be... The tilt angle after software limiting is The tilt angle after error compensation is The final tilt angle is To prevent the target angle from exceeding the allowable range of the mechanism, the reference tilt angle is first limited:

[0061] (2)

[0062] Considering factors such as lead screw drive backlash, connecting component fit errors, and installation errors, compensation is made for the tilt angle after amplitude limiting. Let the compensation amount be... Then the compensated tilt angle is:

[0063] (3)

[0064] To ensure that the compensated target angle remains within the allowable range of the mechanism, it is further limited to obtain the final tilt angle:

[0065] (4)

[0066] The control algorithm ultimately executes the tilt angle. This is the core control variable. Let the servo control angle be... The lower limit of the servo control angle is The upper limit of the servo control angle is Then the tilt angle and the servo control angle satisfy a linear mapping relationship:

[0067] (5)

[0068] To avoid impact caused by a direct jump to the target angle, this invention uses a smooth stepping method to complete the tilt.

[0069] Let the current tilt angle be... The single-step angle increment is The step time interval is The number of steps required for:

[0070] (6)

[0071] when At that time, proceed in the forward step, the first... The step angle of the step satisfies:

[0072] (7)

[0073] when At that time, execute in reverse step order, the first... The step angle of the step satisfies:

[0074] (8)

[0075] The total execution time for a single tilting process is:

[0076] (9)

[0077] In each step, the current step angle is... Convert to the corresponding PWM output value. Let the minimum PWM output value be... The maximum output value of PWM is , No. The corresponding PWM output value for each step is Then we have:

[0078] (10)

[0079] To prevent servo motor jitter caused by the main control cycle repeatedly outputting the same control value, a deduplication criterion for control commands is set. Let the tilt angle executed in the previous control cycle be... The angle update threshold is The control output will only be updated if the following condition is met:

[0080] (11)

[0081] When equation (11) is true, the control executes a new PWM output; when equation (11) is false, the output of the previous cycle remains unchanged. Through hardware structure and control algorithm, the tilting mechanism can achieve smooth tilting within the range of 0 to 90 degrees.

[0082] Traditional servo control involves a step-like angle change, directly moving the servo from... Drive to This will lead to:

[0083] ① The instantaneous start and stop of the servo motor generates mechanical impact, which wears down the transmission components of the tilting mechanism;

[0084] ② Sudden angle changes cause turbulence in the rotor flow field, increasing flight risks;

[0085] ③ The servo motor exhibits jitter, reducing tilt accuracy.

[0086] The smooth step algorithm is to make a single step Total tilt step Decomposed into a tiny step The continuous progression, through small steps, short delays, and continuous drive, achieves smooth tilting without impact or rudder jitter.

[0087] Assuming the total tilt step size triggered by a single key press is The smooth microstep size is The number of smooth steps required to complete a single total step length is: Substitute the values That is, the servo motor completes the task in 5 micro-steps. The tilting motion was without any impact.

[0088] The control method of this invention employs a smooth step control approach, decomposing the target tilt angle into continuous small step outputs instead of a single large-angle jump. Compared to existing direct step control methods, this invention can reduce the impact of servo motor start-stop and sudden changes in power unit attitude, reduce the instantaneous impact on transmission and support components during tilting, and improve the smoothness of operation.

[0089] This invention incorporates PWM command deduplication control, preventing the repeated transmission of the same control command when the output value has not undergone a valid change. Compared to existing methods that continuously and repeatedly issue the same control quantity in the main control loop, this invention reduces invalid servo responses and jitter, enabling the servo to maintain a more stable operating state at the target position. It significantly suppresses servo jitter and improves control stability.

[0090] The following is combined Figures 1 to 6 Specific embodiments are described below.

[0091] Example 1: Specific structure of the tilting mechanism

[0092] The following is combined Figure 1 and Figure 2 The structure of the tilting mechanism is described in detail.

[0093] With the horizontally placed arm 3 as a reference, the root of the arm 3 is fixedly connected to the body of the UAV, and two parallel and vertically upward side plates 20 are fixed above its front end. The two side plates 20 are connected by two parallel support rods 22 to form a rigid support frame.

[0094] The main rotating shaft 14 is horizontally inserted through the upper part of the two side plates 20, and its two ends are fixedly connected to the side plates 20. The motor back plate 5 is a rectangular plate-shaped piece, the middle of which is mounted on the main rotating shaft 14 through bearings, and can rotate freely around the main rotating shaft 14. The front side of the motor back plate 5 (the side facing away from the machine arm 3) is used to fix the power motor, and its back side (the side facing the machine arm 3) is a free surface. The upper end of the motor back plate 5 extends outward to form an upper connecting lug, and the lower end extends outward to form a lower connecting lug.

[0095] Servo 1 is fixed to the outside of one of the side plates 20, with its output shaft extending horizontally through the side plate 20 into the space between the two side plates. One end of servo arm 2 is fixedly connected to the servo output shaft and can swing with the output shaft; the free end of servo arm 2 is hinged to one end of lead screw 4 via a pin. Lead screw 4 extends in a generally horizontal direction, and its other end is hinged to the upper connecting lug of the motor back plate 5 via a fisheye connector 13. The ball end of the fisheye connector 13 is threaded to the lead screw 4, and the seat end is connected to the upper connecting lug via a pin, which can accommodate the angle changes caused by the rotation between the lead screw and the motor back plate.

[0096] The vertical limiter 15 is fixed to the lower part of the inner side of the side plate 20, located on the rotation path of the lower connecting ear of the motor back plate 5. When the motor back plate 5 rotates around the main rotation axis 14 to 0° (the motor axis is vertically upward), the lower connecting ear abuts against the vertical limiter 15. The horizontal limiter 16 is fixed to the rear part of the inner side of the side plate 20 (on the side near the root of the arm 3), located on the rotation path of the back of the motor back plate 5 or the upper connecting ear. When the motor back plate 5 rotates to 90° (the motor axis is horizontally forward), the upper connecting ear or the back of the motor back plate abuts against the horizontal limiter 16.

[0097] When servo 1 receives the PWM signal, the output shaft drives servo arm 2 to swing. When servo arm 2 swings towards arm 3, it pulls lead screw 4 to move backward. Lead screw 4 pulls the upper end of motor back plate 5 to rotate backward through fisheye connector 13. Motor back plate 5 tilts around main rotation axis 14 to the horizontal position (90°). When servo arm 2 swings away from arm 3, it pushes lead screw 4 to move forward, pushing motor back plate 5 to tilt to the vertical position (0°).

[0098] Example 2: Specific Implementation of the Control Method

[0099] The control method in this embodiment follows Figures 3 to 6 The process execution fully adopts the algorithm defined by formulas (1) to (11).

[0100] The control method of this invention is completed by a main program and several subroutines. The main program is used to complete system initialization, input detection, target angle setting, subroutine calling, and status updating; the subroutines include a smooth stepping subroutine, an angle limit and illegal value correction subroutine, and a PWM instruction deduplication and angle output error compensation subroutine. The entire execution process is carried out in the following order:

[0101] Step 1: Power on the system and complete initialization.

[0102] like Figure 3As shown, after the main program starts, it first completes system initialization. Initialization includes: servo drive module initialization, PWM output module initialization, button input module initialization, display module initialization, and tilt angle initialization. After initialization, the main program writes the current angle, target angle, previous cycle output value, and running flag bit into the control variables.

[0103] Step 2: The main program detects external input signals and determines the working mode.

[0104] like Figure 3 As shown, after the main program enters the loop, it first detects external input signals. When a vertical take-off and landing mode command is detected, the main program sets the target angle to the angle corresponding to the vertical working position (0°); when a cruise mode command is detected, the main program sets the target angle to the angle corresponding to the horizontal working position (90°).

[0105] Step 3: The main program generates the target angle and calls the smooth stepping subroutine.

[0106] like Figure 4 As shown, after the target angle is set, the main program calls the smooth stepping subroutine. This subroutine receives the current angle and the target angle, and determines whether the current action is a forward tilt or a reverse rotation. When the target angle is greater than the current angle, the subroutine gradually increases the output according to a preset small step size; when the target angle is less than the current angle, the subroutine gradually decreases the output according to a preset small step size. After each step output is completed, the subroutine inserts a fixed delay to ensure that the servo motor completes a stable response between each step process, achieving a smooth transition of the tilting mechanism.

[0107] Step 4: Perform limit checks and illegal value corrections on the angle output by the subroutine.

[0108] like Figure 5 As shown, after each step angle value is output by the smooth stepping subroutine, the main program calls the angle limit and illegal value correction subroutine. First, it checks whether the current output angle is within the mechanism's allowable range (0°~90°):

[0109] If it is within the allowed range, then maintain that angle and continue execution;

[0110] If the angle is less than the minimum allowable angle (0°), then correct it to 0°;

[0111] If the angle is greater than the maximum allowable angle (90°), then correct it to 90°.

[0112] Simultaneously, by considering the mechanical limit positions corresponding to the vertical and horizontal limit switches, the software output angle is further constrained to ensure that the tilting mechanism always operates within the actual allowable rotation range. For abnormal angle values, illegal input values, or out-of-range commands, corrections are directly performed, and the correction results are returned to the main program.

[0113] Step 5: Execute PWM instructions for deduplication and angle output error compensation.

[0114] like Figure 6 As shown, after completing the limit correction, the main program calls the PWM instruction deduplication and angle output error compensation subroutine. This subroutine reads the servo output value from the previous control cycle and compares it with the current output value:

[0115] When the output value of the current cycle is the same as the output value of the previous cycle, or when the change between the two does not meet the update conditions, it is determined to be a duplicate instruction and the PWM signal will not be resent in order to avoid jitter in the servo during the control process.

[0116] When the output value of this cycle meets the update conditions, the transmission deviation caused by the lead screw, fisheye connector and assembly error is further combined to compensate and correct the output angle, and the PWM control quantity corresponding to the compensated angle is sent to the servo motor.

[0117] Once completed, the output value is written to the history cache for comparison in the next control cycle.

[0118] Step 6: The main program updates the running status and determines whether the target location has been reached.

[0119] like Figure 3 As shown, after completing the subroutine call, the main program updates the system's operating status. The updates include: the current actual angle, the target angle arrival flag, the current operating mode flag, and the PWM output value of the previous cycle.

[0120] If the current angle has not yet reached the target angle, the main program continues to enter the next loop and executes the steps of smooth stepping, limit correction, deduplication and compensation output again.

[0121] If the current angle has been detected as having reached the target angle, the main program will maintain the current position output and wait for the next mode switching instruction.

[0122] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0123] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A tilting mechanism for a tilting hexacopter unmanned aerial vehicle, characterized in that, include: Arm (3) is used to connect to the drone body; The support frame is fixedly mounted on the arm (3); The motor back plate (5) is rotatably mounted on the support frame via the main rotating shaft (14) and is used to support the power motor; The drive assembly, mounted on the support frame, includes a servo motor (1), a servo arm (2), a lead screw (4), and a fisheye connector (13) connected in sequence for transmission. The fisheye connector (13) is hinged to the motor backplate (5). The rotational motion output by the servo motor (1) is converted into linear displacement by the servo arm (2), lead screw (4) and fisheye connector (13), which pushes the motor back plate (5) to tilt around the main rotation axis (14) between the vertical working position and the horizontal working position; The support frame is also provided with a vertical limiter (15) and a horizontal limiter (16), which are used to abut against the motor back plate (5) at the vertical working position and the horizontal working position, respectively.

2. The tilting mechanism according to claim 1, characterized in that, The support frame includes two side plates (20) arranged opposite to each other and a support rod (22) connecting the two side plates (20). The two ends of the main rotating shaft (14) are respectively installed on the two side plates (20).

3. The tilting mechanism according to claim 1, characterized in that, The vertical working position corresponds to a tilt angle of 0° on the motor back plate (5), and the horizontal working position corresponds to a tilt angle of 90°.

4. A control method for the tilting mechanism according to any one of claims 1 to 3, characterized in that, include: Receive mode switching instructions and determine the target tilt angle; The target tilt angle is subjected to amplitude limiting and error compensation to obtain the execution tilt angle; The target tilt angle is limited to ensure that it does not exceed the mechanical range defined by the vertical and horizontal working positions. The tilt angle is decomposed into multiple step increments, and the corresponding PWM signals are output sequentially according to the set time interval to drive the servo motor, so that the motor backplate gradually approaches the target tilt angle; In each control cycle, if the difference between the current PWM signal to be output and the PWM signal output in the previous cycle is less than a preset threshold, the output of the previous cycle will remain unchanged.

5. The control method according to claim 4, characterized in that, The limiting and error compensation specifically include: limiting the initial target tilt angle for the first time to make it fall within the mechanically permissible range; Error compensation is performed on the tilt angle after the first amplitude limiting to eliminate the angle deviation caused by transmission clearance and installation error; The compensated tilt angle is then subjected to a second limit to obtain the final executed tilt angle.

6. The control method according to claim 4, characterized in that, The magnitude of the step increment and the time interval are preset according to the servo motor response characteristics and the inertia of the tilting mechanism, so that there is no mechanical impact during the tilting process.

7. The control method according to claim 4, characterized in that, Also includes: The final tilt angle and servo control angle are converted according to a linear mapping relationship, where the two ends of the linear mapping relationship correspond to the lower limit and upper limit of the servo control angle, respectively.

8. The control method according to claim 4, characterized in that, The difference is the angle difference, and the preset threshold is greater than 0.

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