Autonomous control method for a small, unmanned helicopter

• US 20040245378A1
• Filed: 02/26/2004
• Published: 12/09/2004
• Est. Priority Date: 02/26/2003
• Status: Abandoned Application

• Current Assignee: Daigo Fujiwara, Hirobo Limited, Jin O.K. Shin, Kensaku Hazawa, Kenzo Nonami
• Original Assignee: Daigo Fujiwara, Hirobo Limited, Jin O.K. Shin, Kensaku Hazawa, Kenzo Nonami
• Inventors: Nonami, Kenzo, Fujiwara, Daigo, Shin, Jin Ok, Matsusaka, Keitaro, Hazawa, Kensaku
• Application Number:
  US10/786,051
• Publication Number:
  US 20040245378A1
• Time in Patent Office: Days
• US Class Current: 244/17.13
• CPC Class Codes: A63H 27/12 Helicopters A63H27/04 takes precedence; Flying tops
• CPC Class Codes: A63H 30/04 using wireless transmission
• CPC Class Codes: G05D 1/0033 by having the operator tracking the vehicle either by direct line of sight or via one or more cameras located remotely from the vehicle
• CPC Class Codes: G05D 1/0858 specially adapted for vertical take-off of aircraft

Abstract

An objective of the present invention is to provide an autonomous control method that autonomously controls a small unmanned helicopter toward target values, such as a set position and velocity, by deriving model formulas that are well suited for the autonomous control of small unmanned helicopters, by designing an autonomous control algorithm based on the model formulas, and by calculating the autonomous control algorithm.

The autonomous control system for a small unmanned helicopter of the present invention comprises: sensors that detect the current position, the attitude angle, the altitude relative to the ground, and the absolute azimuth of the nose of the aforementioned small unmanned helicopter; a primary computational unit that calculates optimal control reference values for driving the servo motors that move five rudders on the helicopter from target position or velocity values that are set by the ground station and the aforementioned current position and attitude angle of the small unmanned helicopter that are detected by the aforementioned sensors; an autonomous control system equipped with a secondary computational unit that converts the data collected by said sensors and the computational results as numeric values that are output by said primary computational unit into pulse signals that can be accepted by the servo motors, such that these components are assembled into a small frame box, thereby achieving both size and weight reductions;

a ground station host computer that can also be used as the aforementioned computational unit for the aforementioned autonomous control system;

if the aforementioned ground station host computer is used as the aforementioned computational unit for the aforementioned autonomous control system,

in the process of directing the computational results that are output from said ground station host computer to said servo motors through a manual operation transmitter, a radio control generator that converts said computational results as numerical values into pulse signals that said manual operation transmitter can accept;

a servo pulse mixing/switching apparatus, on all said servo motors for said small unmanned helicopter, that permits the switching of manual operation signals and said control signals that are output from said autonomous control system or mixing thereof in any ratio;

an autonomous control algorithm wherein the mathematical model for transfer function representation encompassing pitching operation input through pitch axis attitude angles in the tri-axis orientation control for said small unmanned helicopter is defined as $G_{\theta }\left(s\right)={}^{-\mathrm{Ls}}\frac{K_{\theta }{\omega }_{ns}^2}{\left(s^2+2{}_s{\omega }_ss+{\omega }_{ns}^2\right)\left(T_{\theta }s+1\right)s}$

such that the aforementioned small unmanned helicopter is controlled autonomously based on the aforementioned mathematical model;

Claims

1. An autonomous control program for a small unmanned helicopter wherein the program detects the current position, the attitude angle, the altitude relative to the ground, and the absolute azimuth of the nose of the small unmanned helicopter;

establishes position or velocity reference values from the ground station;

determines optimal control reference values for driving the servo motors that move a number of helicopter rudders from the current position and attitude angle of said small unmanned helicopter detected by said sensors;

based upon said computational processing results, effects translational motion control and tri-axial orientation control on the small unmanned helicopter;

or

defines the mathematical model for transfer function representation including pitching operation input and pitch axis attitude angles in the tri-axial orientation control for said small unmanned helicopter as

$\begin{array}{cc}{G}_{\mathrm{\theta <br><br>}}<br><br>\left(s\right)={\mathrm{<br><br>}}^{-\mathrm{Ls}}<br><br>\frac{K_{\mathrm{\theta <br><br>}}<br><br>{\mathrm{\omega <br><br>}}_{n<br><br>\text{\hspace{1em}<br><br>}<br><br>s}^2}{\left(s^2+2<br><br>{\mathrm{<br><br>}}_s<br><br>{\mathrm{\omega <br><br>}}_s<br><br>s+{\mathrm{\omega <br><br>}}_{n<br><br>\text{\hspace{1em}<br><br>}<br><br>s}^2\right)<br><br>\left(T_{\mathrm{\theta <br><br>}}<br><br>s+1\right)<br><br>s}& \left(13\right)\end{array}$

and based upon said model equations, causes said primary computational unit to calculate optimal control reference values for driving the servo motors.

7. The autonomous control method for a small unmanned helicopter of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, said primary computational unit for said autonomous control system autonomously controls said small unmanned helicopter by executing independent autonomous control algorithms on the six physical quantities of said small unmanned helicopter:

pitch axis attitude angle, roll axis attitude angle, yaw axis attitude angle, longitudinal speed, lateral speed, and vertical speed.

8. The autonomous control method for a small unmanned helicopter of claim 1, wherein said small unmanned helicopter is autonomously controlled by constructing the respective autonomous control algorithms as a type 1 servo system so that for the respective physical quantities of said small unmanned helicopter, the steady-state deviation from any reference value will be zero.

9. The autonomous control method for a small unmanned helicopter of claim 7, wherein said small unmanned helicopter is autonomously controlled by applying either the linear quadratic Gaussian (LQG) theory or the linear quadratic integral (LQI) theory to the autonomous control algorithms that are constituted as a type 1 servo system, by treating the respective autonomous control algorithms as uncoupled transfer function representation mathematical models.

10. The autonomous control method for a small unmanned helicopter of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, dynamic characteristics consisting of longitudinal speeds and lateral speeds are represented as mathematical models for which pitch axis attitude angles and roll axis attitude angles are input quantities, and said small unmanned helicopter is controlled autonomously by calculating the respective attitude angles that are necessary for effecting arbitrary longitudinal and lateral speeds.

11. The autonomous control method for a small unmanned helicopter of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, in order to move said small unmanned helicopter to an arbitrary position, longitudinal, lateral, and vertical speed reference values are defined as follows:

Vxref=α

(Pxref−

Px) 

 

(19)

for a longitudinal reference value,

Vyref=α

(Pyref−

Py) 

 

(20)

for a lateral value, and

Vzref=β

(Pzref−

Pz) 

 

(21)

for a vertical reference value,

thereby effecting the autonomous control of said small unmanned helicopter.

12. The small unmanned helicopter autonomous control method of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, and further, the transfer function representation mathematical model including the rolling force and rolling axis attitude angles in the tri-axial orientation control for said small unmanned helicopter is defined as

13. The small unmanned helicopter autonomous control algorithm of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, and further, the transfer function representation mathematical model including the yawing force and yawing axis attitude angles in the tri-axial orientation control for said small unmanned helicopter is defined as

14. The small unmanned helicopter autonomous control method of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, and further, the transfer function representation mathematical model including the pitching axis attitude angle and the longitudinal speed in the tri-axial orientation control for said small unmanned helicopter is defined as

15. The small unmanned helicopter autonomous control method of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, and further, the transfer function representation mathematical model including the rolling axis attitude angle and the lateral speed in the translational motion control for said small unmanned helicopter is defined as

16. The small unmanned helicopter autonomous control method of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, and further, the transfer function representation mathematical model for the vertical speed in the translational motion control for said small unmanned helicopter is defined as

17. The autonomous control method for a small unmanned helicopter of claim 1, wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, the transfer function representation mathematical model that describes the dynamic characteristics of said servo motors included in said Eqs. 13 and 14 is defined as

18. The autonomous control method for a small unmanned helicopter of claim 1 wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, the parameters that are included in said Eqs. 13 through 18, specifically, parameters K_θ

, and T_θ

, contained in Eq. 13;

parameters K_φ

, and T_φ

, contained in Eq. 14;

parameters K_ψ

and T_ψ

contained in Eq. 15;

parameters T and a contained in Eq. 17; and

parameter k contained in Eq. 18 are adjusted so that their experimental results and simulation results will agree, autonomous control algorithms are designed according to the resulting values, and said small unmanned helicopter is thereby autonomously controlled.

19. A small unmanned helicopter autonomous control method wherein, in determining optimal control reference values for driving the servo motors that drive the rudders for the small unmanned helicopter, sine wave signals representing arbitrary frequency, amplitude, and time values are entered into said servo motors by manual operation, and during this process, said sine wave signals are obtained by using a function that outputs manual operation signals that are input into said servo pulse mixing/switching unit of a servo pulse mixing/switching unit that is an external device to said autonomous control system;

wherein, simultaneously, the flight status of said small unmanned helicopter is obtained by means of said sensors for said autonomous control system, and wherein the parameters contained in Eqs. 13 through 18 in claim 1 are determined by analyzing the interrelationship between the various pieces of data thus obtained, and wherein autonomous control algorithms are created based on the mathematical models thus obtained.

2. An autonomous control program for a small unmanned helicopter wherein the program detects the current position, the attitude angle, the altitude relative to the ground, and the absolute azimuth of the nose of the small unmanned helicopter;

establishes position or velocity reference values from the ground station;

determines optimal control reference values for driving the servo motors that move a number of helicopter rudders from the current position and attitude angle of said small unmanned helicopter detected by said sensors;

based upon said computational processing results, effects translational motion control and tri-axial orientation control on the small unmanned helicopter;

or

defines the mathematical model for a transfer function representation including the rolling input and roll axis attitude angles in the tri-axial orientation control for said small unmanned helicopter as

$\begin{array}{cc}{G}_{\mathrm{\phi <br><br>}}<br><br>\left(s\right)={\mathrm{<br><br>}}^{-\mathrm{Ls}}<br><br>\frac{K_{\mathrm{\phi <br><br>}}<br><br>{\mathrm{\omega <br><br>}}_{n<br><br>\text{\hspace{1em}<br><br>}<br><br>s}^2}{\left(s^2+2<br><br>{\mathrm{<br><br>}}_s<br><br>{\mathrm{\omega <br><br>}}_{n<br><br>\text{\hspace{1em}<br><br>}<br><br>s}<br><br>s+{\mathrm{\omega <br><br>}}_{n<br><br>\text{\hspace{1em}<br><br>}<br><br>s}^2\right)<br><br>\left(T_{\mathrm{\phi <br><br>}}<br><br>s+1\right)<br><br>s}& \left(14\right)\end{array}$

and based upon said model equations, causes said primary computational unit to calculate optimal control reference values for driving the servo motors.

3. An autonomous control method for a small unmanned helicopter wherein the method detects the current position, the attitude angle, the altitude relative to the ground, and the absolute azimuth of the nose of the small unmanned helicopter;

establishes position or velocity reference values from the ground station;

determines optimal control reference values for driving the servo motors that move a number of helicopter rudders from the current position and attitude angle of said small unmanned helicopter detected by said sensors;

based upon said computational processing results, effects translational motion control and tri-axial orientation control on the small unmanned helicopter;

or

defines the mathematical model for transfer function representation including yawing input and yawing axis attitude angles in the tri-axial orientation control for said small unmanned helicopter as

$\begin{array}{cc}{G}_{\mathrm{\psi <br><br>}}<br><br>\left(s\right)={\mathrm{<br><br>}}^{-\mathrm{Ls}}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{K_{\mathrm{\psi <br><br>}}<br><br>{\mathrm{\omega <br><br>}}_{n<br><br>\text{\hspace{1em}<br><br>}<br><br>s}^2}{\left(s^2+2<br><br>{\mathrm{<br><br>}}_s<br><br>{\mathrm{\omega <br><br>}}_{n<br><br>\text{\hspace{1em}<br><br>}<br><br>s}<br><br>s+{\mathrm{\omega <br><br>}}_{n<br><br>\text{\hspace{1em}<br><br>}<br><br>s}^2\right)<br><br>s}& \left(15\right)\end{array}$

and based upon said model equations, causes said primary computational unit to calculate optimal control reference values for driving the servo motors.

4. An autonomous control method for a small unmanned helicopter wherein the method detects the current position, the attitude angle, the altitude relative to the ground, and the absolute azimuth of the nose of the small unmanned helicopter;

establishes position or velocity reference values from the ground station;

determines optimal control reference values for driving the servo motors that move a number of helicopter rudders from the current position and attitude angle of said small unmanned helicopter detected by said sensors;

based upon said computational processing results, effects translational motion control and tri-axial orientation control on the small unmanned helicopter;

or

defines the mathematical model for transfer function representation including pitching axis attitude angles and the longitudinal speed in the tri-axial orientation control for said small unmanned helicopter as

$\begin{array}{cc}\mathrm{Vx}=g<br><br>\frac{T}{s+T}<br><br>\frac{a}{s-a}<br><br>\left(-\mathrm{\Theta <br><br>}\right)& \left(16\right)\end{array}$

and based upon said model equations, causes said primary computational unit to calculate optimal control reference values for driving the servo motors.

5. An autonomous control method for a small unmanned helicopter wherein the method detects the current position, the attitude angle, the altitude relative to the ground, and the absolute azimuth of the nose of a small unmanned helicopter;

establishes position or velocity reference values from the ground station;

determines optimal control reference values for driving the servo motors that move a number of helicopter rudders from the current position and attitude angle of said small unmanned helicopter detected by said sensors;

based upon said computational processing results, effects translational motion control and tri-axial orientation control on the small unmanned helicopter;

or

defines the mathematical model for transfer function representation including rolling axis attitude angles and the lateral speed in the translational motion control for said small unmanned helicopter as

$\begin{array}{cc}\mathrm{Vy}=g<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{T}{s+T}<br><br>\frac{a}{s-a}<br><br>\mathrm{\Phi <br><br>}& \left(17\right)\end{array}$

and based upon said model equations, causes said primary computational unit to calculate optimal control reference values for driving the servo motors.

6. An autonomous control method for a small unmanned helicopter wherein the method detects the current position, the attitude angle, the altitude relative to the ground, and the absolute azimuth of the nose of the small unmanned helicopter;

establishes position or velocity reference values from the ground station;

determines optimal control reference values for driving the servo motors that move a number of helicopter rudders from the current position and attitude angle of said small unmanned helicopter detected by said sensors;

based upon said computational processing results, effects translational motion control and tri-axial orientation control on the small unmanned helicopter;

or

defines the mathematical model for transfer function representation of the vertical speed in the translational motion control for said small unmanned helicopter as

$\begin{array}{cc}\mathrm{Vz}=\frac{k}{s}<br><br>{\mathrm{\Theta <br><br>}}_i& \left(18\right)\end{array}$

and based upon said model equations, causes said primary computational unit to calculate optimal control reference values for driving the servo motors.