Underactuated aircraft time-coordinated optimal arc guidance method

Abstract

The application discloses a time coordination optimal arc guidance method for an underactuated aircraft, and the method is used for solving the problem of intersection docking of the aircraft with multiple constraints. The method is based on an arc, and the predictive correction thought and the optimal control theory are adopted. When the method is applied to the guidance of the underactuated aircraft, the desired time constraint can be met without speed adjustment, more accurate time control can be realized, and energy consumption is relatively small.

Claims

1. A time-coordinated optimal circular arc guidance method for underactuated aircraft, characterized in that, In this method, based on the expected terminal time t d Real-time acquisition of guidance commands a M Then through the guidance command a M Control the actuators on the aircraft to make it fly toward the target.

2. The time-coordinated optimal circular arc guidance method for underactuated aircraft according to claim 1, characterized in that, The guidance command a M Obtained through the following formula (i): a M = a c + a b (1) Among them, a c This indicates an acceleration command for circular arc guidance. a b This represents the optimal guidance command that satisfies the terminal time constraint.

3. The time-coordinated optimal circular arc guidance method for underactuated aircraft according to claim 2, characterized in that, The circular arc-guided acceleration command a c We obtain it through the following formula (ii): Where V represents the speed of the aircraft; r represents the distance between the aircraft and the target; η represents the leading angle.

4. The time-coordinated optimal circular arc guidance method for underactuated aircraft according to claim 2, characterized in that, The optimal guidance command a that satisfies the terminal time constraint b We obtain it through the following formula (iii): Where V represents the speed of the aircraft; η represents the leading angle; n represents the weighting coefficient; ε t Indicates the prediction time error; Indicates the remaining flight time.

5. The time-coordinated optimal circular arc guidance method for underactuated aircraft according to claim 4, characterized in that, The prediction time error ε t We obtain it through the following formula (iv): in, This indicates the predicted end time.

6. The time-coordinated optimal circular arc guidance method for underactuated aircraft according to claim 5, characterized in that, The predicted end time Obtained through the following formula (5): Where t represents the current time, which is counted from the start of control.

7. The time-coordinated optimal circular arc guidance method for underactuated aircraft according to claim 4, characterized in that, The remaining flight time Obtained through the following formula (VI):

8. The time-coordinated optimal circular arc guidance method for underactuated aircraft according to claim 4, characterized in that, The leading angle η is obtained by the following formula (VII): η=θ-λ(VII) Where θ represents the heading angle, λ represents the line-of-sight angle.

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