JP3189025B2 - Aircraft attitude control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flying object attitude control apparatus for automatically controlling the attitude of a radio-controlled unmanned helicopter.

[0002]

2. Description of the Related Art Conventionally, a radio-controlled unmanned helicopter for spraying pesticides, for example, has a structure in which the azimuth, inclination angle, etc. of an airframe are remotely controlled by a pilot command signal from a pilot. In this type of unmanned helicopter, the actual azimuth, inclination angle, etc. of the aircraft are affected by disturbances such as wind, etc. with respect to the azimuth, inclination angle, etc., determined by the pilot command signal so that maneuvering can be performed easily. It has been desired to provide an attitude control device that automatically corrects the attitude of the aircraft even if it changes.

The attitude control device detects the actual angle of inclination of the fuselage with respect to the earth by a sensor, and controls various types of helicopters so that the deviation between the detected value and a target value set by a pilot command signal becomes zero. What is necessary is just to comprise so that a servomotor may be controlled. In detail, the inclinometer consisting of an acceleration sensor detects how much the axis that is the main azimuth of the fuselage left, right, front and back is tilted with respect to the vertical direction, and the fuselage moves around the vertical axis to the reference azimuth of the earth. What is necessary is just to detect how much it turns by the geomagnetic azimuth sensor and perform control to bring these detected values closer to the target value.

[0004]

However, if the acceleration sensor is used to detect the inclination angle of the fuselage with respect to the vertical direction of the airframe, the acceleration sensor detects the acceleration caused by the flight when the helicopter is flying. It is not possible to measure the exact tilt angle due to the influence. For this reason, there has been a problem that the accuracy is reduced when the above-described automatic attitude control is performed.

It is also conceivable to employ an angular velocity sensor such as a gyro in place of the acceleration sensor and integrate the angular velocity output from the angular velocity sensor to obtain the angle.
Since the angular velocity sensor can obtain only the change in the angle with respect to the initial value, the inclination angle with respect to the vertical direction cannot be obtained. In addition, there is a problem that the zero point of the angular velocity value changes due to the increase and decrease of the temperature of the gyro. The error based on the change of the zero point becomes extremely large even if the change of the zero point is very small by performing the integration for a long period of time.

The present invention has been made to solve such a problem. Even if the zero point of an angular velocity sensor such as a gyro has changed, the zero point is corrected, and an automatic detection is performed using the angle detected using the gyro. An object of the present invention is to enable accurate posture control.

[0007]

According to a first aspect of the present invention, there is provided an attitude control apparatus for an airplane, comprising: an angular velocity sensor for detecting an angular velocity when the airframe rotates with respect to a reference axis of a main azimuth of forward, backward, left, right, and vertical directions. An angular velocity reference value setting means for obtaining an average value of angular velocities within a fixed time when the aircraft is stationary, and integrating a true angular velocity obtained by subtracting the average value from the angular velocity detected by the angular velocity sensor to obtain a main azimuth of the aircraft. An attitude angle calculation means for obtaining a rotation angle with respect to a reference axis, and a body control means for controlling a body attitude based on the rotation angle are provided.

A flying object attitude control device according to a second aspect of the present invention is the flying object attitude control device according to the first aspect,
Before taking off, the attitude angle calculation means detects the inclination angle and the azimuth angle of the main azimuth of the aircraft with respect to the earth by a sensor, and adds the rotation angle of the aircraft obtained from the true angular velocity to the inclination angle and the azimuth angle. Is configured to detect the posture of the user.

[0009]

Since the angular velocity output by the angular velocity sensor when the aircraft is stationary is an error due to a change in the zero point, the true angular velocity is obtained by subtracting this error from the value of the angular velocity actually output by the angular velocity sensor. In the first invention, the attitude control is performed by detecting the attitude of the airframe from the rotation angle obtained by integrating the true angular velocity.

In the second invention, the attitude of the airframe is detected by adding the rotation angle obtained from the true angular velocity to the inclination angle and the azimuth angle with respect to the earth obtained before takeoff, and the attitude control is performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a schematic configuration diagram of an unmanned helicopter equipped with a flying object attitude control device according to the present invention, FIG. 2 is a block diagram showing an overall configuration of the flying object attitude control device according to the present invention, and FIG. FIG. 4 is a block diagram showing the configuration, FIG. 4 is a flowchart for explaining the zero point detection operation of the flying object attitude control apparatus according to the present invention, and FIG. 5 is a graph showing a state when the value of the angular velocity is corrected. In the present embodiment, an example will be described in which the attitude control device for a flying object according to the present invention is applied to an attitude control device for an unmanned helicopter.

In these figures, 1 is an unmanned helicopter body, 2 is a main rotor, 3 is a tail rotor, and 4 is an engine that drives the main rotor 2 and the tail rotor 3 to rotate. Reference numeral 5 denotes an engine controller servo motor for controlling the number of revolutions of the engine 4, reference numeral 6 denotes a collective servo motor for controlling the inclination angle and pitch angle of the main rotor 2, and reference numeral 7 denotes a ladder servo motor for controlling the pitch angle of the tail rotor 3. , These servo motors 5
7 is a controller 8 as an attitude control device according to the present invention.
The structure is controlled by

Reference numeral 9 denotes a receiver mounted on the body 1. The receiver 9 receives a pilot command signal transmitted from a transmitter 10 by a receiver 9a and outputs the pilot command signal to a controller 8.
The control signal from the controller 8
7 is built in. Although not shown, the machine 1 is equipped with a pesticide spraying device for spraying pesticides from the air.

The controller 8 detects the angles of the main body 1 with respect to three main directions (left, right, front and rear, and vertical directions) orthogonal to each other, the altitude of the main body, acceleration in the vertical direction, and the like using various sensors described later. The structure is such that the target flight state set by the pilot command signal sent from the transmitter 10 is controlled. here,
As the sensor, the horizontal axis (X axis) of the body 1
Acceleration sensor 11 as inclinometer for detecting rotation angle
And an angular velocity sensor 12, an acceleration sensor 13 and an angular velocity sensor 14 as inclinometers for detecting an angle around the longitudinal axis (Y axis) of the body 1, and an angle around a vertical axis (Z axis) of the body 1 A geomagnetic azimuth sensor 15 and an angular velocity sensor 16 for detecting the acceleration, an elevation sensor 17 for detecting the acceleration of the body 1 in the vertical direction,
Altitude sensor 18 for detecting the altitude of the
An engine speed detection sensor 19 (FIG. 2) for detecting the speed of the engine.

Among these sensors, an X-axis acceleration sensor 11 detects how much the Y-axis of the body 1 is inclined with respect to the vertical direction, and an X-axis angular velocity sensor 12 detects that the body 1 is rotated about the X-axis. It is configured to detect an angular velocity when rotating. The Y-axis acceleration sensor 13 detects how many times the X-axis of the body 1 is inclined with respect to the vertical direction, and the Y-axis angular velocity sensor 14 detects the angular velocity when the body 1 rotates around the Y-axis. It is configured to detect.

Further, the geomagnetic azimuth sensor 15 detects, for example, how many times the Y-axis of the fuselage has turned with respect to the north azimuth,
The Z-axis angular velocity sensor 16 is configured to detect an angular velocity when the body 1 rotates around the Z-axis. In addition, the elevation sensor 17 is configured to detect a moving direction and a moving speed of the body 1 in the Z-axis direction, and the altitude sensor 18 is configured to optically detect a distance between the body 1 and the ground. . Furthermore, the engine speed detection sensor 19 is configured to detect the rotation of the engine 4.

The angular velocity sensors 12, 14, 1
For the embodiment 6, an optical fiber gyro is employed in this embodiment.

As shown in FIG. 2, the controller 8 calculates an actual attitude angle of the airframe 1 from the output values of the various sensors. And a flight state control CPU 22 for controlling the servomotors 5 to 7 so that the actual attitude angle approaches the target attitude angle and the flight direction, engine speed and altitude approach target values. The flight state control CPU 22 calculates target values such as a target attitude angle, a target flight direction, and a target flight speed based on a pilot command signal transmitted from the transmitter 10, and as described above, Each of the servo motors 5 to 7 is provided with an actuator control amount calculation processing means for controlling the servo motors. Note that the flight state control CPU 22 constitutes an airframe control unit according to the present invention.

As shown in FIG. 3, the attitude angle computing device 21 includes a CPU 23 for performing various calculations, and an interface for connecting the sensors and the flight state control CPU 22 to the CPU 23. The CPU 23 of the attitude angle calculation device 21 includes a stationary determination processing unit 24 for detecting whether the body 1 is stationary, and the CPU 23 when the stationary determination processing unit 24 determines that the body 1 is stationary. Angular velocity calculation processing means 25 for setting an average value of the output values of the angular velocity sensors 12, 14, 16 as an angular velocity reference value; and after the angular velocity calculation processing means 25 determines the angular velocity reference value, the acceleration sensors 11, 13 and the geomagnetic azimuth. Tilt angle / azimuth calculating means 26 for obtaining the tilt angle and azimuth of the body 1 from the sensor 15 with respect to the earth; output values of the angular velocity sensors 12, 14, 16; angular velocity reference values obtained by the angular velocity calculating processing means 25; Inclination angle
And a current attitude angle calculating means 27 for calculating the current attitude angle of the body 1 from the angle determined by the azimuth angle calculating means 26. The stationary judgment processing means 24 and the angular velocity calculation processing means 25 constitute an angular velocity reference value setting means according to the present invention, and the current attitude angle computing means 27 constitutes an attitude angle computing means according to the present invention. .

Here, a more detailed configuration of the CPU 23 will be described with reference to the flowchart of FIG. This CPU
When the power is turned on, first, at step S in FIG.
As shown in FIG. 1, the angular velocity calculation processing means 25 reads the angular velocities ωX, ωY, ωZ output from the angular velocity sensors 12, 14, 16 and increases Δω with respect to the angular velocity reference value ω0 for each angular velocity as shown in step S2. Is calculated. As the angular velocity reference value ω0, a predetermined value is substituted immediately after power-on, and in other cases, a value obtained by an angular velocity calculation processing unit 25 described later is substituted. The substitution value immediately after the power is turned on is, for example, the average value of the angular velocities ωX, ωY, and ωZ input during a few seconds immediately after the power is turned on. Note that the angular velocity ω0 substituted in cases other than immediately after the power is turned on is determined for each of the X axis, the Y axis, and the Z axis.

Thereafter, in step S3, the stationary judgment processing means 24 determines the absolute value of the increase Δω and a predetermined value β.
And it is determined whether the increment Δω is smaller than β. The set value β is set to a value small enough to include a minute signal output from the angular velocity sensors 12, 14, 16 while the body 1 is stationary. Until the airframe 1 takes off, the absolute value of the increment Δω becomes smaller than the set value β. At this time, the process proceeds to step S4. After takeoff, the absolute value of the increase Δω becomes larger than the set value β, and at this time, the process proceeds to step S5.

When the process proceeds to step S4, the angular velocity calculation processing means 25 starts measuring time, and thereafter, as shown in steps S6 to S7, integrates the angular velocities ωX, ωY, ωZ until the time T0 elapses. After integrating the angular velocities in this way, the angular velocity calculation processing means 25 calculates the average values of the angular velocities CωX, CωY, CωZ by dividing the integrated values ΣωX, ΣωY, ΣωZ by the elapsed time T0 in step S8.
This is set as the angular velocity reference value ω0 (X, Y, Z) of each of the angular velocity sensors 12, 14, 16. After this angular velocity reference value ω0 is set, it is stored in a memory (not shown) until it is reset.

That is, by proceeding from steps S1 to S8, an error contained in the output values of the angular velocity sensors 12, 14, 16 is detected as ω0. The error .omega.0 is caused by a rise in the temperature of the angular velocity sensors 12, 14, 16 or the like. This angular velocity reference value ω0 is used as the output value ω of the angular velocity sensors 12, 14, 16.
By subtracting each from X, ωY, and ωZ, the true angular velocity can be obtained. This subtraction is performed by a current attitude angle calculation means 27 described later.

After setting the angular velocity reference value ω0 as described above, the tilt / azimuth calculating means 26 calculates the angle of the aircraft 1 based on the output values of the acceleration sensors 11 and 13 and the geomagnetic azimuth sensor 15 as shown in step S9. The attitude of the Earth to the Earth. At this time, the inclination angles φX and φY of the body 1 with respect to the vertical direction of the X and Y axes, and the angle φZ with respect to the north direction of the Y axis, for example, are detected. Note that these inclination angles φX, φY and φZ are stored in a memory (not shown) together with the angular velocity reference value ω0 until the next time they are updated. Thereafter, in step S10, the angular velocity calculation processing means 25 resets the integration time.

If it is determined in step S3 that the absolute value of the increment Δω is larger than the set value β, the angular velocity calculation processing means 25 clears the integrated angular velocity values ΣωX, ΣωY, ΣωZ in step S5. The process proceeds to step S10 to reset the accumulated time.

After the completion of the processing in step S10, the flow returns to step S1 to repeat the above-described control.

The CPU 23 executes steps S1 to S10 described above.
While performing the zero point detection operation shown in FIG.
7 to calculate the current attitude angle. The current attitude angles θX, θY, θZ are as follows (1) to
It is calculated based on equation (3). θX = α ｛θn-1 + (ωX−ω0X) Δt｝ + (1−α) φX (1) θY = α {θn−1 + (ωY−ω0Y) Δt} + (1−α) φY・ (2) θZ = α ｛θn-1 + (ωZ-ω0Z) Δt｝ + (1-α) φZ (3)

In the above equation, ω0X is an angular velocity reference value obtained based on the output of the X-axis angular velocity sensor 12, and ω0Y
Is an angular velocity reference value determined based on the output of the Y-axis angular velocity sensor 14, and ω0Z is an angular velocity reference value determined based on the output of the Z-axis angular velocity sensor 16. That is, the angular velocity reference values ω0X, ω0Y, ω0Z are subtracted from the output values ωX, ωY, ωZ of the angular velocity sensors 12, 14, 16 to obtain the true angular velocity, and the true angular velocity is integrated. The attitude angle (θn-1) obtained at the time of the cycle is added to the tilt angles φX, φY and the angle φZ obtained by the tilt angle / azimuth calculating means 26 to calculate. Also, the variable α
Is a mixture ratio of the integrated values of the attitude angle (θn-1) and the true angular velocity, and the inclination angles φX, φY, and the angle φZ.

The current attitude angles θX, θY, θZ obtained by the current attitude angle calculation means 27 are input to the flight state control CPU 22. The flight state control CPU 22 controls the servo motors 5 to 7 so that the attitude angles θX, θY, θZ coincide with the target attitude angles.

Next, the operation of the controller 8 configured as described above will be described with reference to FIG. FIG.
A change in the output value of the angular velocity sensor when the engine 4 is started when indicated by s, and after that, the takeoff and landing is repeated twice and the takeoff is further performed is shown. In the drawing, the range indicated by reference symbol A indicates the first flight, the range indicated by B indicates the second flight, and the range indicated by C indicates the third flight. Also,
The angular velocity ω indicated by the solid line in FIG.
An output example of any one of 2, 14, and 16 is shown.

First, when the power is turned on, the control shown in FIG. 4 is performed, the angular velocity reference value ω0 is set, and the current attitude angles θX, θY, θZ are initialized. In this control, after the power is turned on, the absolute value of the angular velocity increment Δω is equal to the set value β.
It is repeated until it becomes larger. In other words,
Repeated until takeoff. Therefore, even if the pilot changes the position of the aircraft 1 after the power is turned on and before takeoff, the current attitude angles θX, θY, θZ of the controller 8 are changed.
Is always updated to the latest angle. In the flowchart of FIG. 4, the calculation is repeated individually in the order of X, Y, and Z.

After the engine 4 is started at time ts in FIG. 5, the transmitter 10 takes off and the controller 8 controls the servomotors 5 to 7 so as to follow the pilot command signal, thereby controlling the airframe. Take off one. After takeoff, the angular velocities ωX, ωY, ωZ detected by the angular velocity sensors 12, 14, 16 are sufficiently larger than the set value β because the absolute value obtained by subtracting ω0 is sufficiently large.
From step S5 to step S10, and the angular velocity reference value ω0 and the angles θX, θY and θZ are not updated.

During the flight, the current attitude angle calculating means 2
7 is the current output value ω of the angular velocity sensors 12, 14, 16
From X, ωY, ωZ, the angular velocity reference value ω0, the inclination angles φX, φY, and the angle φZ, which are obtained and stored before takeoff, the current attitude angle is calculated based on the above equations (1) to (3). The flight state control CPU 22 controls the servomotors 5 to 7. That is, during the flight, the angular velocity sensors 12, 14,
The current attitude angle and azimuth are detected by using the angular velocity detected by 16.

When the first flight indicated by reference symbol A in FIG. 5 is performed for, for example, 15 minutes and the landing is performed as indicated by reference symbol a in FIG. 5, the temperature of the angular velocity sensor is several degrees Celsius compared to before takeoff. It was found to rise. At this time, the warm-up time before takeoff was about 3 minutes. As a result, the output value of the angular velocity sensor has a zero point shifted from that before takeoff due to a rise in temperature.

When the output value of the angular velocity sensor is smaller than that during flight, such as after landing, and the absolute value of the value obtained by subtracting the angular velocity reference value ω0 from this output value is smaller than the set value β, the flowchart of FIG. The control from step S3 to step S10 via step S4 is performed. That is, the average value of the angular velocity values output from the angular velocity sensor during a predetermined time T0 after landing is updated as a new angular velocity reference value ω0, and the acceleration sensor 1
1, 13 and the tilt angles φX, φY and azimuth φZ detected by the geomagnetic direction sensor 15 are used as the current attitude angles θX, θY,
θZ. By updating the angular velocity reference value ω0 in this manner, even if the output value of the angular velocity sensor increases due to a temperature rise or the like, the value of the angular velocity reference value ω0 subtracted from this output value also increases. The error contained in the output value is removed.

For this reason, at the time of the second and third flights indicated by symbols B and C in FIG. 5, the controller 8 calculates the current attitude angle based on the true angular velocity.

Therefore, when the controller 8 is used, the current attitude angle of the body 1 can be detected by using a true angular velocity obtained by subtracting an error from the angular velocity output from the angular velocity sensor. For this reason, in automatically performing the attitude control, it is possible to improve accuracy by removing an error existing in the angular velocity sensor.

Further, since the rotation angle obtained from the true angular velocity is added to the inclination angles φX, φY and azimuth φZ with respect to the earth obtained before takeoff, the attitude of the aircraft is detected, and attitude control is performed. Even if disturbance such as wind is applied to the airframe 1, the current attitude of the airframe 1 can be matched with the target attitude with reference to the earth, so that extremely accurate attitude control can be performed.

[0039]

As described above, the flying object attitude control apparatus according to the first aspect of the present invention is an angular velocity sensor for detecting an angular velocity when the aircraft turns with respect to a reference axis of a main azimuth in the front-back, left-right, and vertical directions. And angular velocity reference value setting means for obtaining an average value of the angular velocities within a fixed time when the aircraft is stationary, and integrating the true angular velocity obtained by subtracting the average value from the angular velocity detected by the angular velocity sensor to integrate the main azimuth of the aircraft. The attitude angle calculation means for calculating the rotation angle with respect to the reference axis, and the airframe control means for controlling the attitude of the airframe based on the rotation angle, the attitude of the airframe is calculated from the rotation angle obtained by integrating the true angular velocity. Is detected and attitude control is performed.

For this reason, in automatically performing the attitude control, it is possible to improve the accuracy by removing an error existing in the angular velocity sensor.

A flying object attitude control apparatus according to a second aspect of the present invention is the flying object attitude control apparatus according to the first aspect, wherein:
Before taking off, the attitude angle calculation means detects the inclination angle and the azimuth angle of the main azimuth of the aircraft with respect to the earth by a sensor, and adds the rotation angle of the aircraft obtained from the true angular velocity to the inclination angle and the azimuth angle. Therefore, the attitude of the aircraft is detected by adding the rotation angle obtained from the true angular velocity to the inclination angle with respect to the earth obtained before takeoff, and the attitude control is performed.

For this reason, even if disturbance such as wind is applied to the airframe, the current attitude of the airframe can be matched with the target attitude with respect to the earth, so that extremely accurate attitude control can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an unmanned helicopter equipped with a flying object attitude control device according to the present invention.

FIG. 2 is a block diagram showing an overall configuration of a flying object attitude control apparatus according to the present invention.

FIG. 3 is a block diagram showing a configuration of a main part.

FIG. 4 is a flowchart for explaining a zero point detection operation of the attitude control device for an aircraft according to the present invention.

FIG. 5 is a graph showing a state when a value of an angular velocity is corrected.

[Explanation of symbols]

 1 Body 4 Engine 5 Engine Controller Servo Motor 6 Collective Servo Motor 7 Ladder Servo Motor 8 Controller 9 Receiver 10 Transmitter 11 Acceleration Sensor 12 Angular Velocity Sensor 13 Acceleration Sensor 14 Angular Velocity Sensor 15 Geomagnetic Orientation Sensor 16 Angular Velocity Sensor 21 Attitude Angle Calculator 22 Flight State control CPU 24 Stillness determination processing means 25 Angular velocity calculation processing means 26 Tilt / azimuth calculation means 27 Current attitude angle calculation means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-81792 (JP, A) JP-A-4-46897 (JP, A) JP-A-5-131993 (JP, A) JP-A-5-1993 223587 (JP, A) JP-A-6-190152 (JP, A) JP-A-5-288558 (JP, A) JP-A-3-25910 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B64C 13/16 B64C 27/04 B64C 39/02 G05D 1/08

Claims (2)

(57) [Claims] 1. An angular velocity sensor for detecting an angular velocity when the airframe rotates with respect to a reference axis of a main azimuth of front / rear, left / right, and vertical directions, and the angular velocity sensor detects within a predetermined time when the airframe is stationary. Angular velocity reference value setting means for obtaining an average value of the obtained angular velocities, and a true angular velocity obtained by subtracting the average value from the angular velocity detected by the angular velocity sensor to obtain a rotation angle of the main body with respect to a reference axis in a main direction. An attitude control device for a flying object, comprising: attitude angle calculation means; and body control means for controlling the attitude of the body based on the rotation angle obtained by the attitude angle calculation means. 2. The attitude control apparatus for an air vehicle according to claim 1, wherein the attitude angle calculating means detects an inclination angle and an azimuth angle of a reference axis of a main azimuth of the aircraft with respect to the earth by a sensor before takeoff. An attitude control device for an aircraft, wherein the attitude of the aircraft is detected by adding a rotation angle of the aircraft obtained from a true angular velocity to an angle and an azimuth angle.