IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0861502
(2010-08-23)
|
등록번호 |
US-8185259
(2012-05-22)
|
발명자
/ 주소 |
|
출원인 / 주소 |
- King Fahd University of Petroleum & Minerals
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
4 인용 특허 :
3 |
초록
▼
The fuzzy logic-based control method for helicopters carrying suspended loads utilizes a controller based on fuzzy logic membership distributions of sets of load swing angles. The anti-swing controller is fuzzy-based and has controller outputs that include additional displacements added to the helic
The fuzzy logic-based control method for helicopters carrying suspended loads utilizes a controller based on fuzzy logic membership distributions of sets of load swing angles. The anti-swing controller is fuzzy-based and has controller outputs that include additional displacements added to the helicopter trajectory in the longitudinal and lateral directions. This simple implementation requires only a small modification to the software of the helicopter position controller. The membership functions govern control parameters that are optimized using a particle swarm algorithm. The rules of the anti-swing controller are derived to mimic the performance of a time-delayed feedback controller. A tracking controller stabilizes the helicopter and tracks the trajectory generated by the anti-swing controller.
대표청구항
▼
1. A fuzzy logic-based control method for a helicopter carrying a suspended load, comprising the steps of: providing a helicopter attitude and position tracking controller, the controller being designed to generate outputs for stabilizing the helicopter while accepting tracking commands from a refer
1. A fuzzy logic-based control method for a helicopter carrying a suspended load, comprising the steps of: providing a helicopter attitude and position tracking controller, the controller being designed to generate outputs for stabilizing the helicopter while accepting tracking commands from a reference source and displacement commands from a feedback source as inputs, the design including feedback gain (k) based on minimizing a load swing history, wherein the load swing history is represented by a Linear Quadratic Regulator method, the Linear Quadratic Regulator method depending on minimizing the quadratic function, Indx=∫0tf(ⅇTQe+ηTRη)ⅆt wherein Indx represents the feedback gain matrix integral over time tf, wherein ηT and η represent helicopter control inputs, wherein eT represents an error signal, wherein Qe represents an angular velocity of a helicopter, and wherein R is a position vector of the load with respect to a center of mass of the helicopter; determining helicopter dynamics, suspended load forces and suspended load dynamics, the suspended load dynamics including load swing angles;providing a fuzzy logic-based anti-swing controller, the fuzzy logic-based anti-swing controller issuing the displacement commands to the helicopter attitude and position tracking controller, the displacement commands being based on fuzzy logic rules operable on a plurality of normalized fuzzy membership functions governing all fuzzy inputs and outputs and derived from time-delayed feedback of the load swing angles represented by the equation: xs=kdxLΦL(t−τdx)ys=kdyLθL(t−τdy) where xs and ys are additional displacement outputs added to the helicopter trajectory in a longitudinal and lateral direction, wherein φL is the load angle in a xz plane and θL is the load angle out of a xz plane, respectively, k is a feedback gain, L is a load cable length and τ is a time delay introduced in a feedback model of the load swing angles, the fuzzy inputs including θL and θL rate, the fuzzy outputs including a longitudinal displacement; optimally selecting values for the k, and τ parameters by minimizing an index function expressed in terms of a time history of the load swing, the index function minimizing being performed using an evolutionary computation algorithm; andimplementing an optimized fuzzy logic-based anti-swing controller in a feedback control loop with the tracking controller to achieve suspended load swing reduction of the suspended load and stability control of the helicopter. 2. The fuzzy logic-based control method according to claim 1, wherein said evolutionary computation algorithm is a particle swarm optimization algorithm. 3. The fuzzy logic-based control method according to claim 1, further comprising configuring five of the membership functions corresponding to the θL input, the five membership functions including Negative Big (NB), Negative Small (NS), Zero (ZO), Positive Small (PS) and Positive Big (PB), wherein at least two of the membership functions overlap. 4. The fuzzy logic-based control method according to claim 3, further comprising the steps of: overlapping the NS membership function with the NB membership function;overlapping the Z0 membership function with the NS membership function;overlapping the PS membership function with the ZO membership function; andoverlapping the PB membership function with the PS membership function. 5. The fuzzy logic-based control method according to claim 1, further comprising the step of configuring three of said membership functions corresponding to said θL rateinput, said three membership functions including Negative Big (NB), Zero (ZO), and Positive Big (PB), wherein at least two of said membership functions overlap. 6. The fuzzy logic-based control method according to claim 5, further comprising the steps of: overlapping the ZO membership function with the NB membership function; andoverlapping the PB membership function with the ZO membership function. 7. The fuzzy logic-based control method according to claim 1, further comprising the step of configuring three of the membership functions corresponding to one of the displacementoutputs, the three membership functions including Negative Big (NB), Zero (ZO), and Positive Big (PB), wherein at least two of the membership functions overlap. 8. The fuzzy logic-based control method according to claim 7, further comprising the steps of: overlapping the ZO membership function with the NB membership function; andoverlapping the PB membership function with the ZO membership function. 9. The fuzzy logic-based control method according to claim 1, further comprising the steps of: assigning ranges to the normalized membership functions; andusing scaling factors to transform the ranges of the normalized membership functions to physical operating ranges based on a maximum value of the load swings and a maximum value of the helicopter displacements. 10. A computer software product, comprising a non-transitory storage medium readable by a processor, the medium having stored thereon a set of instructions for issuing displacement control commands to a helicopter carrying a suspended load while in hover flight, the set of instructions including: (a) a first sequence of instructions which, when executed by the processor, causes said processor to configure a helicopter attitude and position tracking controller, the helicopter attitude and position tracking controller being designed to generate outputs for stabilizing the helicopter while accepting tracking commands from a reference source and displacement commands from a feedback source as inputs, the design configuration including feedback gain k based on minimizing a load swing history, wherein the load swing history is represented by a Linear Quadratic Regulator method, the Linear Quadratic Regulator method depending on minimizing the quadratic function: Indx=∫0tf(eTQe+ηTRη)ⅆt wherein Indx represents the feedback gain matrix integral over time tf, wherein ηT and η represent helicopter control inputs, wherein eT represents an error signal, wherein Qe represents an angular velocity of a helicopter, and wherein R is a position vector of the load with respect to a center of mass of the helicopter; (b) a second sequence of instructions which, when executed by the processor, causes said processor to determine helicopter dynamics, suspended load forces and suspended load dynamics, the suspended load dynamics including load swing angles;(c) a third sequence of instructions which, when executed by the processor, causes said processor to configure an anti-swing controller, the anti-swing controller issuing the displacement commands to the helicopter attitude and position tracking controller the displacement commands being based on time-delayed feedback of the load swing angles represented by the equation: xs=kdxLΦL(t−τdx)ys=kdyLθL(t−τdy) where Xs, and ys are additional displacement added to the helicopter trajectory in a longitudinal and lateral direction, wherein φL is the load angle in a xz plane and θL is the load angle out of a xz plane, respectively, k is a feedback gain, L is a load cable length and τ is a time delay introduced in the feedback of the load swing angles, the fuzzy inputs including θL and θL rate, the fuzzy outputs including a longitudinal displacement; (d) a fourth sequence of instructions which, when executed by the processor, causes said processor to optimally select values for the k, and τ parameters by minimizing an index function expressed in terms of a time history of the load swing, the index function minimizing being performed using an evolutionary computation algorithm, the index function minimizing being performed using an evolutionary computation algorithm; and(e) a fifth sequence of instructions which, when executed by the processor, causes said processor to implement an optimized anti-swing controller in a feedback control loop with the tracking controller to achieve suspended load swing reduction and stability control of the helicopter. 11. The computer software product according to claim 10 wherein said evolutionary computation algorithm is a particle swarm optimization algorithm. 12. The computer software product according to claim 10, wherein the set of instructions further comprises: (f) a sixth sequence of instructions which, when executed by the processor, causes said processor to configure five of the membership functions corresponding to the θL input, the five membership functions including Negative Big (NB), Negative Small (NS), Zero (ZO), Positive Small (PS) and Positive Big (PB), wherein at least two of the membership functions overlap. 13. The computer software product according to claim 12, wherein the set of instructions further comprises: (g) a seventh sequence of instructions which, when executed by the processor, causes said processor to: overlap the NS membership function with the NB membership function;overlap the Z0 membership function with the NS membership function;overlap the PS membership function with the ZO membership function; andoverlap the PB membership function with the PS membership function. 14. The computer software product according to claim 10, wherein the set of instructions further comprises: (h) an eighth sequence of instructions which, when executed by the processor, causes said processor to configure three of the membership functions corresponding to the θL rateinput, the three membership functions including Negative Big (NB), Zero (ZO), and Positive Big (PB), wherein at least two of the membership functions overlap. 15. The computer software product according to claim 14, wherein the set of instructions further comprises: (i) a ninth sequence of instructions which, when executed by the processor, causes said processor to: overlap the ZO membership function with the NB membership function; andoverlap the PB membership function with said ZO membership function. 16. The computer software product according to claim 10, wherein the set of instructions further comprises: (j) a tenth sequence of instructions which, when executed by the processor, causes said processor to configure three of the membership functions corresponding to one of the displacement outputs, the three membership functions including Negative Big (NB), Zero (ZO), and Positive Big (PB), wherein at least two of the membership functions overlap. 17. The computer software product according to claim 16, wherein the set of instructions further comprises: (k) an eleventh sequence of instructions which, when executed by the processor, causes said processor to: overlap the ZO membership function with the NB membership function; andoverlap the PB membership function with the ZO membership function. 18. The computer software product according to claim 10, wherein the set of instructions further comprises: (I) a twelfth sequence of instructions which, when executed by the processor, causes said processor to assign ranges to the normalized membership functions; and use scaling factors to transform the ranges of the normalized membership functions to physical operating ranges based on a maximum value of the load swings and a maximum value of the helicopter displacements.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.