Adaptive control method for unmanned vehicle with slung load

• US 9,146,557 B1
• Filed: 04/23/2014
• Issued: 09/29/2015
• Est. Priority Date: 04/23/2014
• Status: Expired due to Fees

• Current Assignee: King Fahd University of Petroleum & Minerals (Government of Saudi Arabia)
• Original Assignee: King Fahd University of Petroleum & Minerals (Government of Saudi Arabia)
• Inventors: Ferik, Sami El, Ahmed, Ghufran
• Primary Examiner(s): Frejd, Russell
• Application Number:
  US14/260,096
• Time in Patent Office: 524 Days
• Field of Search: 701/3, 701/4, 701/10, 703/2, 703/6, 703/8, 700 28- 32, 700 47- 50, 244/8, 244/17.11, 244/177, 244/181, 244/75.1, 706/2, 706/14, 706/16, 706/905, 706/913
• US Class Current: 1/1
• CPC Class Codes: B64C 17/00 Aircraft stabilisation not otherwise provided for
• CPC Class Codes: B64C 19/00 Aircraft control not otherwise provided for
• CPC Class Codes: B64D 1/22 Taking-up articles from earth's surface
• CPC Class Codes: B64U 10/00 Type of UAV
• CPC Class Codes: B64U 10/10 Rotorcrafts
• CPC Class Codes: B64U 10/14 with four distinct rotor axes, e.g. quadcopters
• CPC Class Codes: B64U 2101/60 for transporting passengers; for transporting goods other than weapons
• CPC Class Codes: B64U 2101/64 for parcel delivery or retrieval
• CPC Class Codes: B64U 2201/00 UAVs characterised by their flight controls
• CPC Class Codes: G05B 13/04 involving the use of models or simulators
• CPC Class Codes: G05D 1/08 Control of attitude, i.e. control of roll, pitch, or yaw
• CPC Class Codes: G05D 1/0808 specially adapted for aircraft
• CPC Class Codes: G05D 1/0816 to ensure stability
• CPC Class Codes: G05D 1/0825 using mathematical models
• CPC Class Codes: G05D 1/085 to ensure coordination between different movements
• CPC Class Codes: G05D 1/0858 specially adapted for vertical take-off of aircraft

Abstract

The adaptive control method for an unmanned vehicle with a slung load utilizes a feedback linearization controller (FLC) to perform vertical take off, hovering and landing of an unmanned aerial vehicle with a slung load, such as a quadrotor drone or the like. The controller includes a double loop architecture, where the overall controller includes an inner loop having an inner controller which is responsible for controlling the attitude angles and the altitude, and an outer loop having an outer controller responsible for providing the inner loop inner controller with the desired angle values. States, such as including roll, pitch, yaw and/or altitude, are selected as outputs and the feedback linearization technique is used.

Claims

1. An adaptive control method for an unmanned vehicle with a slung load, comprising the steps of:

establishing a feedback linear controller, such that f(x)=M_b({umlaut over (x)}_ad+Λ

ė

_xa)+C_b({dot over (x)}_ad+Λ

e_xa)+D_b{dot over (x)}_a+G_b, wherein f(x) is a control dynamics input for an unmanned aerial vehicle, x_ad is a vector representing roll, pitch, yaw and altitude for the unmanned aerial vehicle based on a corresponding trajectory, M_b is an inertia matrix associated with the unmanned aerial vehicle, C_b is a centrifugal force and coriolis force matrix associated with the unmanned aerial vehicle, D_b is a drag force matrix associated with the unmanned aerial vehicle, and G_b is a gravitational vector, {dot over (x)}_a being a velocity vector such that

2. The adaptive control method for an unmanned vehicle with a slung load as recited in claim 1, wherein the tuning algorithm comprises calculating Ŵ

and {circumflex over (V)}, respectively, as {circumflex over ({dot over (W)})}=F{circumflex over (σ

)}y^T and {circumflex over ({dot over (V)})}=Gx({circumflex over (σ

)}′

^TŴ

y)^T, where F and G are each positive definite matrices representing design parameters.

3. The adaptive control method for an unmanned vehicle with a slung load as recited in claim 2, wherein K_xc=K_yc=0.4L, and τ

_xc=τ

_yc=0.32T_L, where T_L is a period of oscillation of the slung load.

4. A computer software product that includes a non-transitory storage medium readable by a processor, the non-transitory storage medium having stored thereon a set of instructions for performing adaptive control for an unmanned vehicle with a slung load, the instructions comprising:

(a) a first set of instructions which, when loaded into main memory and executed by the processor, causes the processor to establish a feedback linear controller, such that f(x)=M_b({umlaut over (x)}_ad+Λ

ė

_xa)+C_b({dot over (x)}_ad+Λ

e_xa)+D_b{dot over (x)}_a+G_b, wherein f(x) is a control dynamics input for an unmanned aerial vehicle, x_ad is a vector representing roll, pitch, yaw and altitude for the unmanned aerial vehicle based on a corresponding trajectory, M_b is an inertia matrix associated with the unmanned aerial vehicle, C_b is a centrifugal force and coriolis force matrix associated with the unmanned aerial vehicle, D_b is a drag force matrix associated with the unmanned aerial vehicle, and G_b is a gravitational vector, {dot over (x)}_a being a velocity vector such that

5. The computer software product as recited in claim 4, wherein the third set of instructions further comprises calculating Ŵ

and {circumflex over (V)}, respectively, as {circumflex over ({dot over (W)})}=F{circumflex over (σ

)}y^T and {circumflex over ({dot over (V)})}=Gx({circumflex over (σ

)}′

^TŴ

y)^T, where F and G are each positive definite matrices representing design parameters.

6. The computer software product as recited in claim 5, wherein K_xc=K_yc=0.4L, and τ

_xc=τ

_yc=0.32T_L, where T_L is a period of oscillation of the slung load.