Single-encoder actuator for an aircraft and power-on self-test method therefor

Abstract

The application discloses a single-encoder actuator for an aircraft and a power-on self-checking method thereof. A controller controls a servo motor to rotate through a vector control algorithm, and the motor drives a rudder arm to rotate through a harmonic reducer. In combination with the feature of the harmonic reducer that there is no backlash, the original point is found when the actuator is powered on each time to perform stroke self-checking, and the position of the output shaft rudder arm can be calculated through the recorded rotor turns and the read rotor position. Therefore, the cost and installation difficulty are reduced while the high performance requirement is met.

Description

Technical Field

[0001] This invention relates to the field of aircraft actuator technology, and more specifically, to a single encoder actuator for aircraft and its power-on self-test method. Background Technology

[0002] An actuator is a servo drive device used for position or angle control. It is widely used in aircraft and other equipment for operations such as aircraft control surfaces.

[0003] Existing rotary actuators mainly fall into two categories: 1. Low-cost approach: The controller uses a 6-step square wave algorithm to control the rotation of a hollow cup motor. The motor drives the control arm to rotate after passing through a multi-stage parallel shaft gear reducer. During control arm rotation, a potentiometer feeds back the output shaft position to the controller. This type of actuator suffers from large reducer backlash, poor overload capacity, large motor torque ripple, low potentiometer repeatability, and poor stability, thus failing to meet the performance requirements of high-performance aircraft actuators, which demand fast response, high precision, and good stability. 2. High-cost approach: The controller uses a vector control algorithm to control the rotation of a servo motor. The motor drives the control arm to rotate after passing through a planetary or harmonic reducer. During control arm rotation, an absolute encoder feeds back the output shaft position to the controller. This type of actuator offers fast response, high precision, and good stability, but the use of a dual-encoder scheme also results in high cost, difficult installation, and large size.

[0004] Prior art discloses an actuator system for the control surface of an aircraft and the aircraft itself, comprising: two fixed plates; an actuator disposed between the two fixed plates and including a fixed unit connected to the two fixed plates and a power transmission movable unit, the movable unit including an output for transmitting power to the control surface of the aircraft to drive the control surface; and a protection device disposed between the two fixed plates and configured to restrict the movement of the fixed unit of the actuator in the event of a connection failure between the fixed unit of the actuator and the fixed plates, wherein the fixed unit of the actuator is connected to the fixed plates via a first connector and a second connector, the first connector and the second connector being disposed on substantially opposite sides of the actuator. This solution does not solve the aforementioned problems. Summary of the Invention

[0005] The primary objective of this invention is to provide a single encoder actuator for aircraft that reduces cost and installation difficulty while meeting high performance requirements.

[0006] A further objective of this invention is to provide a power-on self-test method for a single encoder actuator used in aircraft.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0008] A single encoder actuator for aircraft includes a controller, a servo motor, a harmonic reducer, a control arm, and a limit post, wherein:

[0009] The receiver of the controller receives control commands from the flight controller. The output of the controller is connected to the servo motor. The harmonic reducer reduces the speed of the servo motor and drives the rudder arm of the output shaft to rotate. The limit post is set on the rotation path of the rudder arm to limit the maximum rotation angle of the rudder arm. The mechanical origin and electrical zero point are found through the limit post to realize the rudder arm's origin return during power-on self-test.

[0010] The servo motor is equipped with a rotor position encoder at the motor end. The rotor position encoder at the motor end feeds back the rotor position and rotor speed of the servo motor to the controller. The controller also acquires the current of the servo motor. After calculating and processing the control commands sent by the flight controller, the rotor position of the servo motor, the rotor speed of the servo motor, and the current of the servo motor, the controller outputs three-phase AC power to the servo motor to drive the servo motor.

[0011] Preferably, the controller includes a sampling circuit, through which the controller acquires the three-phase AC power of the servo motor.

[0012] Preferably, the controller calculates and processes the control commands sent by the flight controller, the rotor position of the servo motor, the rotor speed of the servo motor, and the current of the servo motor, and then outputs three-phase AC power to the servo motor. Specifically:

[0013] After receiving control commands from the flight controller, the controller, in its position loop, calculates the control command value, the recorded number of rotor revolutions, and the rotor position fed back by the rotor position encoder at the motor end, and outputs a speed command to the speed loop. In the speed loop, it calculates the speed command and the speed value fed back by the rotor position encoder at the motor end, and outputs a current command to the current loop. In the current loop, it calculates the current command and the current fed back by the sampling circuit, and outputs a set of direct-axis voltages Vd and quadrature-axis voltages Vq for coordinate transformation. In the coordinate transformation, it calculates the direct-axis voltage Vd and the rotor position fed back by the rotor position encoder at the motor end, and outputs a set of pulse width modulation (PWM) signals to the inverter circuit. In the inverter circuit, the PWM signals are amplified and then output as three-phase AC power to the servo motor.

[0014] Preferably, the harmonic reducer is a backlash-free harmonic reducer.

[0015] Preferably, the relationship between the number of rotations of the motor rotor and the rotor position and the angle of the output shaft rudder arm is as follows:

[0016]

[0017]

[0018]

[0019] In the formula, θ ArmRelative θ is the relative angle between the rudder arms, in degrees. rotor 1 is the rotor angle in degrees; N is the reduction ratio of the harmonic reducer; R is the number of rotor rotations; n is the reading value of the rotor position encoder at the motor end after one rotation; r is the current value of the rotor position encoder at the motor end.

[0020] Preferably, there are two limiting posts, which are respectively set on the lower mechanical limit point and the upper mechanical limit point on the rotation path of the rudder arm. The maximum angle position reached in the clockwise direction on the rotation path of the rudder arm is the lower mechanical limit point, and the maximum angle position reached in the counterclockwise direction is the upper mechanical limit point.

[0021] Preferably, on the rotation path of the rudder arm, from the lower mechanical limit point to the upper mechanical limit point, a mechanical origin, an electrical zero point, and an electrical maximum point are sequentially set. The mechanical origin is the mechanical zero point used as a reference during the rotation of the rudder arm. The electrical zero point is a set offset relative to the mechanical origin, which serves as the minimum stroke amount when the actuator is working normally. The electrical maximum point is a set stroke amount relative to the electrical zero point, which serves as the maximum stroke amount when the actuator is working normally.

[0022] Preferably, the return of the rudder arm to its origin during the power-on self-test specifically involves:

[0023] After power-on, the rudder arm moves clockwise from its initial state until it hits the limit post at the lower mechanical limit point, then moves counterclockwise until it hits the limit post at the upper mechanical limit point, and then moves clockwise until the Z signal of the rotor position encoder at the motor end appears. At this point, the position is the mechanical origin. After moving to the set electrical zero point, the rudder arm returns to its origin.

[0024] Preferably, after finding the mechanical origin and electrical zero point through the limit pins, the absolute angle of the rudder arm is calculated as follows:

[0025] θ ArmAbsolute =θ ArmRelative +θ ArmZero

[0026] In the formula, θ ArmAbsolute θ represents the absolute angle of the rudder arm, measured in degrees. ArmRelative θ represents the relative angle between the rudder arms, in degrees. ArmZeroThe angle corresponding to the electrical zero position of the rudder arm is expressed in degrees.

[0027] A power-on self-test method for a single encoder actuator for aircraft as described above includes the following steps:

[0028] S1: Actuator powered on;

[0029] S2: Find the lower mechanical limit: The rudder arm moves clockwise from the initial state until it touches the limit post located at the lower mechanical limit point;

[0030] S3: Find the upper mechanical limit: The rudder arm moves counterclockwise until it touches the limit post located at the upper mechanical limit point;

[0031] S4: Find the mechanical origin: The rudder arm moves clockwise until the Z signal of the rotor position encoder at the motor end appears;

[0032] S5: The rudder arm moves to the electrical zero point, completing the rudder arm's return to the origin.

[0033] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0034] The single-encoder actuator for aircraft of this invention uses a controller to control the rotation of a servo motor via a vector control algorithm. The motor drives the control arm to rotate through a harmonic reducer. By combining the backlash-free characteristic of the harmonic reducer with the actuator's self-check during each power-on stroke to find the origin, the position of the output shaft control arm can be calculated by recording the number of rotor revolutions and reading the rotor position. This reduces cost and installation difficulty while meeting high performance requirements. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the single encoder actuator for aircraft according to the present invention.

[0036] Figure 2 This is a schematic diagram of the control surface of a single encoder actuator for an aircraft, provided as an example.

[0037] Figure 3 This is a schematic diagram of a single encoder actuator control for an aircraft, provided as an example.

[0038] Figure 4 This is a schematic diagram of the limit post setting for a single encoder actuator for an aircraft provided in an embodiment.

[0039] Figure 5 A schematic diagram of the power-on self-test method for a single encoder actuator for an aircraft provided in this embodiment.

[0040] In the diagram, 1 is the servo motor, 2 is the harmonic reducer, 3 is the rudder arm, 4 is the controller, and 5 is the limit post. Detailed Implementation

[0041] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0042] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions;

[0043] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

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

[0045] Example 1

[0046] A single encoder actuator for an aircraft, such as Figure 1 As shown, it includes a controller 4, a servo motor 1, a harmonic reducer 2, a steering arm 3, and a limit post 5, wherein:

[0047] The receiver of the controller 4 receives control commands from the flight controller. The output of the controller 4 is connected to the servo motor 1. The harmonic reducer 2 reduces the speed of the servo motor 1 and drives the rudder arm 3 of the output shaft to rotate. The limit post 5 is set on the rotation path of the rudder arm 3 to limit the maximum rotation angle of the rudder arm 3. The mechanical origin and electrical zero point are found through the limit post 5 to realize the origin return of the rudder arm 3 during power-on self-test.

[0048] The servo motor 1 is equipped with a rotor position encoder at the motor end. The rotor position encoder at the motor end feeds back the rotor position and rotor speed of the servo motor 1 to the controller 4. The controller 4 also acquires the current of the servo motor 1. The controller 4 calculates and processes the control commands sent by the flight controller, the rotor position of the servo motor 1, the rotor speed of the servo motor 1, and the current of the servo motor 1, and then outputs three-phase AC power to the servo motor 1 to drive the servo motor 1.

[0049] In specific embodiments, such as Figure 2 As shown, the actuator's control arm 3 is connected to the aircraft's control surface and drives the control surface.

[0050] Example 2

[0051] This embodiment discloses a single encoder actuator for aircraft, such as... Figure 1 As shown, it includes a controller 4, a servo motor 1, a harmonic reducer 2, a steering arm 3, and a limit post 5, wherein:

[0052] The receiver of the controller 4 receives control commands from the flight controller. The output of the controller 4 is connected to the servo motor 1. The harmonic reducer 2 reduces the speed of the servo motor 1 and drives the rudder arm 3 of the output shaft to rotate. The limit post 5 is set on the rotation path of the rudder arm 3 to limit the maximum rotation angle of the rudder arm 3. The mechanical origin and electrical zero point are found through the limit post 5 to realize the origin return of the rudder arm 3 during power-on self-test.

[0053] The servo motor 1 is equipped with a rotor position encoder at the motor end. The rotor position encoder at the motor end feeds back the rotor position and rotor speed of the servo motor 1 to the controller 4. The controller 4 also acquires the current of the servo motor 1. The controller 4 calculates and processes the control commands sent by the flight controller, the rotor position of the servo motor 1, the rotor speed of the servo motor 1, and the current of the servo motor 1, and then outputs three-phase AC power to the servo motor 1 to drive the servo motor 1.

[0054] In specific embodiments, such as Figure 2 As shown, the actuator's control arm 3 is connected to the aircraft's control surface and drives the control surface.

[0055] The controller 4 includes a sampling circuit, which collects the three-phase AC power of the servo motor 1.

[0056] The controller 4 calculates and processes the control commands sent by the flight controller, the rotor position of the servo motor 1, the rotor speed of the servo motor 1, and the current of the servo motor 1, and then outputs three-phase AC power to the servo motor 1. Specifically:

[0057] like Figure 3 As shown, after receiving the control command from the flight controller, the controller 4, in its position loop, calculates the control command value, the recorded number of rotor revolutions, and the rotor position fed back by the rotor position encoder at the motor end, and outputs a speed command to the speed loop of the controller 4. In the speed loop of the controller 4, after calculating the speed command and the speed value fed back by the rotor position encoder at the motor end, it outputs a current command to the current loop of the controller 4. In the current loop of the controller 4, after calculating the current command and the current fed back by the sampling circuit, it outputs a set of direct-axis voltage Vd and quadrature-axis voltage Vq for coordinate transformation to the controller 4. In the coordinate transformation of the controller 4, after calculating the direct-axis voltage Vd and the rotor position fed back by the rotor position encoder at the motor end, it outputs a set of pulse width modulation (PWM) signals to the inverter circuit of the controller 4. In the inverter circuit of the controller 4, the PWM signals are amplified and output as three-phase AC power to the servo motor 1.

[0058] The harmonic reducer 2 is a backlash-free harmonic reducer 2.

[0059] The relationship between the number of rotations of the motor rotor and the rotor position and the angle of the output shaft rudder arm is as follows:

[0060]

[0061]

[0062]

[0063] In the formula, θ ArmRelative θ is the relative angle between the rudder arms, in degrees. rotor 1 is the rotor angle in degrees; N is the reduction ratio of the harmonic reducer; R is the number of rotor rotations; n is the reading value of the rotor position encoder at the motor end after one rotation; r is the current value of the rotor position encoder at the motor end.

[0064] There are two limiting posts 5, such as Figure 3 As shown, the lower mechanical limit point and the upper mechanical limit point are respectively set on the rotation path of the rudder arm 3. The maximum angle position reached in the clockwise direction on the rotation path of the rudder arm 3 is the lower mechanical limit point, and the maximum angle position reached in the counterclockwise direction is the upper mechanical limit point.

[0065] Along the rotation path of the rudder arm 3, from the lower mechanical limit point to the upper mechanical limit point, a mechanical origin, an electrical zero point, and an electrical maximum point are sequentially set. The mechanical origin is the mechanical zero point used as a reference during the rotation of the rudder arm 3. The electrical zero point is a set offset relative to the mechanical origin, which serves as the minimum stroke amount when the actuator is working normally. The electrical maximum point is a set stroke amount relative to the electrical zero point, which serves as the maximum stroke amount when the actuator is working normally.

[0066] The return of the rudder arm 3 to its origin during the power-on self-test is specifically as follows:

[0067] After power-on, the rudder arm 3 moves clockwise from its initial state until it hits the limit post 5 located at the lower mechanical limit point, then moves counterclockwise until it hits the limit post 5 located at the upper mechanical limit point, and then moves clockwise until the Z signal of the rotor position encoder at the motor end appears. At this time, the position is the mechanical origin. After moving to the set electrical zero point, the origin return of the rudder arm 3 is completed.

[0068] After finding the mechanical origin and electrical zero point through the limit post 5, the absolute angle of the rudder arm 3 is calculated as follows:

[0069] θ ArmAbsolute =θ ArmRelative +θ ArmZero

[0070] In the formula, θ ArmAbsolute θ is the absolute angle of rudder arm 3, in degrees.ArmRelative θ is the relative angle of rudder arm 3, in degrees. ArmZero The angle corresponding to the electrical zero position of rudder arm 3 is in degrees.

[0071] Example 3

[0072] This embodiment provides a power-on self-test method for a single encoder actuator for aircraft as described in Embodiments 1 and 2. Figure 4 As shown, it includes the following steps:

[0073] S1: Actuator powered on;

[0074] S2: Find the lower mechanical limit: The rudder arm 3 moves clockwise from the initial state until it touches the limit post 5 located at the lower mechanical limit point;

[0075] S3: Find the upper mechanical limit: The rudder arm 3 moves counterclockwise until it touches the limit post 5 located at the upper mechanical limit point;

[0076] S4: Find the mechanical origin: Rotary arm 3 moves clockwise until the Z signal of the rotor position encoder at the motor end appears;

[0077] S5: The rudder arm 3 moves to the electrical zero point, completing the return of the rudder arm 3 to its origin.

[0078] If the corresponding mechanical limit switch is not found in steps S2 and S3, the self-test fails.

[0079] The same or similar labels correspond to the same or similar parts;

[0080] The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0081] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A single encoder actuator for aircraft, characterized in that, Includes a controller (4), a servo motor (1), a harmonic reducer (2), a steering arm (3), and a limit post (5), wherein: The receiver of the controller (4) receives the control command sent by the flight controller. The output of the controller (4) is connected to the servo motor (1). The harmonic reducer (2) reduces the speed of the servo motor (1) and drives the rudder arm (3) of the output shaft to rotate. The limit post (5) is set on the rotation path of the rudder arm (3) to limit the maximum rotation angle of the rudder arm (3). The mechanical origin and electrical zero point are found through the limit post (5) to realize the origin return of the rudder arm (3) during power-on self-test. The servo motor (1) is equipped with a motor end rotor position encoder. The motor end rotor position encoder feeds back the rotor position and rotor speed of the servo motor (1) to the controller (4). The controller (4) also obtains the current of the servo motor (1). The controller (4) calculates and processes the control command sent by the flight controller, the rotor position of the servo motor (1), the rotor speed of the servo motor (1), and the current of the servo motor (1), and outputs three-phase AC power to the servo motor (1) to drive the servo motor (1). The actuator's control arm (3) is connected to the aircraft's control surface to drive the control surface; There are two limiting posts (5), which are respectively set on the lower mechanical limit point and the upper mechanical limit point on the rotation path of the rudder arm (3). The maximum angle position reached in the clockwise direction on the rotation path of the rudder arm (3) is the lower mechanical limit point, and the maximum angle position reached in the counterclockwise direction is the upper mechanical limit point. On the rotation path of the rudder arm (3), from the lower mechanical limit point to the upper mechanical limit point, a mechanical origin, an electrical zero point and an electrical maximum point are set in sequence. The mechanical origin is the mechanical zero point used as a reference when the rudder arm (3) rotates. The electrical zero point is a set offset relative to the mechanical origin, which serves as the minimum stroke when the actuator is working normally. The electrical maximum point is a set stroke relative to the electrical zero point, which serves as the maximum stroke when the actuator is working normally.

2. The single encoder actuator for aircraft according to claim 1, characterized in that, The controller (4) includes a sampling circuit, which collects the three-phase AC power of the servo motor (1) through the sampling circuit.

3. The single encoder actuator for aircraft according to claim 2, characterized in that, The controller (4) calculates and processes the control commands sent by the flight controller, the rotor position of the servo motor (1), the rotor speed of the servo motor (1), and the current of the servo motor (1), and then outputs three-phase AC power to the servo motor (1). Specifically: After receiving the control command from the flight controller, the controller (4) calculates the control command value, the recorded number of rotor revolutions, and the rotor position fed back by the rotor position encoder at the motor end in the position loop of the controller (4), and outputs a speed command to the speed loop of the controller (4); in the speed loop of the controller (4), after calculating the speed command and the speed value fed back by the rotor position encoder at the motor end, it outputs a current command to the current loop of the controller (4); in the current loop of the controller (4), after calculating the current command and the current value fed back by the sampling circuit, it outputs a set of direct-axis voltage Vd and quadrature-axis voltage Vq to the coordinate transformation of the controller (4); in the coordinate transformation of the controller (4), after calculating the direct-axis voltage Vd and the rotor position fed back by the rotor position encoder at the motor end, it outputs a set of pulse width modulation signals PWM to the inverter circuit of the controller (4); in the inverter circuit of the controller (4), after amplifying the pulse width modulation signals PWM, it outputs three-phase AC power to the servo motor (1).

4. The single encoder actuator for aircraft according to claim 1, characterized in that, The harmonic reducer (2) is a backlash-free harmonic reducer (2).

5. The single encoder actuator for aircraft according to claim 4, characterized in that, The relationship between the number of rotations of the motor rotor and the rotor position and the angle of the output shaft rudder arm is as follows: In the formula, θ ArmRelative θ is the relative angle between the rudder arms, in degrees. rotor is the rotor angle in degrees; N is the reduction ratio of the harmonic reducer; R is the number of rotor rotations; n is the reading value of the rotor position encoder at the motor end after one rotation; r is the current value of the rotor position encoder at the motor end.

6. The single encoder actuator for aircraft according to claim 1, characterized in that, The return of the rudder arm (3) to its origin during the power-on self-test is specifically as follows: After power-on, the rudder arm (3) moves clockwise from the initial state until it touches the limit post (5) located at the lower mechanical limit point, then moves counterclockwise until it touches the limit post (5) located at the upper mechanical limit point, and then moves clockwise until the Z signal of the rotor position encoder at the motor end appears. At this time, the position is the mechanical origin, and then moves to the set electrical zero point to complete the origin return of the rudder arm (3).

7. The single encoder actuator for aircraft according to claim 6, characterized in that, After finding the mechanical origin and electrical zero point through the limit post (5), the absolute angle of the rudder arm (3) is calculated as follows: i ArmAbsolute =θ ArmRelative +θ ArmZero In the formula, θ ArmAbsolute θ is the absolute angle of the rudder arm (3), in degrees; ArmRelative θ is the relative angle between the rudder arm (3) and the rudder arm (3), in degrees. ArmZero The angle corresponding to the electrical zero position of the rudder arm (3) is in degrees.

8. A power-on self-test method for a single encoder actuator for an aircraft as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Actuator powered on; S2: Find the lower mechanical limit: The rudder arm (3) moves clockwise from the initial state until it touches the limit post (5) located at the lower mechanical limit point; S3: Find the upper mechanical limit: The rudder arm (3) moves counterclockwise until it touches the limit post (5) located at the upper mechanical limit point; S4: Find the mechanical origin: The rudder arm (3) moves clockwise until the Z signal of the rotor position encoder at the motor end appears; S5: The rudder arm (3) moves to the electrical zero point, completing the return of the rudder arm (3) to its origin.

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