CN110824925A - Adaptive robust fault-tolerant control method for tilting type three-rotor unmanned aerial vehicle - Google Patents
Adaptive robust fault-tolerant control method for tilting type three-rotor unmanned aerial vehicle Download PDFInfo
- Publication number
- CN110824925A CN110824925A CN201911197484.2A CN201911197484A CN110824925A CN 110824925 A CN110824925 A CN 110824925A CN 201911197484 A CN201911197484 A CN 201911197484A CN 110824925 A CN110824925 A CN 110824925A
- Authority
- CN
- China
- Prior art keywords
- unmanned aerial
- aerial vehicle
- fault
- vector
- rotor unmanned
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 24
- 230000003044 adaptive effect Effects 0.000 title abstract description 9
- 238000013461 design Methods 0.000 claims abstract description 25
- 239000013598 vector Substances 0.000 claims description 44
- 239000011159 matrix material Substances 0.000 claims description 20
- 238000006243 chemical reaction Methods 0.000 claims description 8
- 238000004458 analytical method Methods 0.000 claims description 7
- 238000012546 transfer Methods 0.000 claims description 4
- 238000003745 diagnosis Methods 0.000 abstract description 7
- 238000004422 calculation algorithm Methods 0.000 abstract description 5
- 230000000694 effects Effects 0.000 description 6
- 238000011217 control strategy Methods 0.000 description 5
- 238000004088 simulation Methods 0.000 description 5
- 230000000903 blocking effect Effects 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 230000036544 posture Effects 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- RZVHIXYEVGDQDX-UHFFFAOYSA-N 9,10-anthraquinone Chemical compound C1=CC=C2C(=O)C3=CC=CC=C3C(=O)C2=C1 RZVHIXYEVGDQDX-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000003384 imaging method Methods 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 210000005045 desmin Anatomy 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 238000005312 nonlinear dynamic Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
- G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
- G05B13/04—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
- G05B13/042—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators in which a parameter or coefficient is automatically adjusted to optimise the performance
Landscapes
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Artificial Intelligence (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Evolutionary Computation (AREA)
- Medical Informatics (AREA)
- Software Systems (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
Abstract
The invention relates to fault-tolerant control of a tilting three-rotor unmanned aerial vehicle, and aims to provide a nonlinear fault-tolerant control algorithm which does not need fault diagnosis, is robust and has high feasibility, so that stable control of attitude motion is realized under the condition that a tail steering engine is blocked by the tilting three-rotor unmanned aerial vehicle. The invention discloses a self-adaptive robust fault-tolerant control method of a tilting type three-rotor unmanned aerial vehicle, which comprises the following steps: establishing a fault model of the tilting three-rotor unmanned aerial vehicle: the method comprises the steps of controller design and adaptive law design, wherein the adaptive law design is based on an adaptive backstepping method and terminal sliding mode control. The invention is mainly applied to the fault-tolerant control occasion of the tilting type three-rotor unmanned aerial vehicle.
Description
Technical Field
The invention relates to a fault-tolerant control problem of a tilting type three-rotor unmanned aerial vehicle. A robust fault-tolerant controller is provided based on a self-adaptive backstepping method and terminal sliding mode control under the condition that a tail steering engine of a tilting three-rotor unmanned aerial vehicle affected by external disturbance and model uncertainty has a blocking fault.
Background
In recent years, small rotor unmanned aerial vehicles are widely applied to the fields of search and rescue, electric power overhaul, aerial photography, logistics transportation and the like, so that scientific researchers perform many related researches. The current major drone configurations include: comparatively common four rotor unmanned aerial vehicle, single rotor helicopter to and three rotor unmanned aerial vehicle that have special construction. Wherein three rotor unmanned aerial vehicle of formula of verting is the unmanned aerial vehicle configuration of a kind between single rotor and four rotor unmanned aerial vehicle, and it not only has advantages such as mobility is strong, but VTOL, compares with four rotor unmanned aerial vehicle moreover, and it possesses characteristics such as compacter mechanism, energy consumption less and longer duration. Correspondingly, the difference between the moment calculation and the dynamic model is generated, the system coupling is increased, and the control difficulty is improved.
With respect to the control problem of tilt-type triple rotor drones, researchers have proposed some control design strategies. A six-degree-of-freedom dynamic model is established for a tilting three-rotor unmanned aerial vehicle with a tiltable steering engine at the tail part by the University of Technology of company, France, and a control strategy based on a saturation function is designed for realizing stable control of the posture and the position of the unmanned aerial vehicle (journal: IEEE Transactions on Aero and electronic Systems; Renders: Sengio Salazar-Cruz, Farid Kendoul, Rogelio Lozano; published month: 2008; article title: Real-time stability of a small rotor-aircraft; page number: 783. 794). A tilting type three-rotor Unmanned aerial vehicle with each rotor capable of independently tilting is designed at the university of higher mining in Paris (Ecole des Mines de Paris), a posture and position controller is designed Based on a flat control theory, and an experimental result under a motion capture system shows that the Unmanned aerial vehicle can realize translation without rotation on a horizontal plane (Conference: International Conference on Unmanned air systems; author: Etienne services, Brigitte d' android Novel, Hugues Mouner; published New year and month: 2015; article: group control of a hybrid tracker; page: 945 and 950).
Small-size rotor unmanned aerial vehicle has the characteristics of high real-time, and its motor, steering wheel are in a high-frequency operating condition for a long time, lead to its probability greatly increased who breaks down, consequently make one of the important direction for unmanned aerial vehicle research field to the fault-tolerant control of unmanned aerial vehicle executor trouble. The university of Central and south China linearizes a four-rotor unmanned aerial vehicle model, uses a Robust adaptive observer to diagnose failure faults of an actuator, uses dynamic output feedback Control to realize stable Control of postures, and verifies the effectiveness of the algorithm through numerical simulation (Journal: International Journal of Control; authors: Xiaohong Nian, Weiqiiang Chen, Xiaoyan Chu; published New year and month: 2018; article title: Robust adaptive failure testing and failure free Control for quadrat issue systems; page: 1-20). Louisiana University (Louisiana State University) uses a high-order sliding mode observer to estimate actuator faults of a quad-rotor unmanned aerial vehicle, achieves fault tolerance effects by using a Control strategy based on STW (Super-twist), and is verified through numerical simulation (Conference: IEEE Conference on Control Technology and Applications; author: Seema Mallavavali, Afef Fekih; published New year and month: 2017; article title: A fault tolerantcontrol approach for a quadrotor UAV subject to time varying interference generators faults; page number: 596-. Tianjin university uses an observer based on I & I (imaging and Invariance) to diagnose a partial failure of the motor of a quad-rotor unmanned aerial vehicle and uses sliding mode control for compensation (journal: Nonlinear Dynamics; authors: Wei Hao, Bin Xiao, published.2017; article title: Nonlinear fault-tall control for a quadrat base on imaging and regulation method; page: 2813-. They also establish a dynamic model of the tilting three-rotor unmanned aerial vehicle by using unit quaternion, design an observer based on STW and a controller based on RISE (robust Integral of the Signal of the error), and realize stable control of the unmanned aerial vehicle in case of failure (journal: IEEEtransactions on Industrial information; Bin Xian, Wei Hao; published New year and month: 2018; article title: nonliner robust fault free control of the tilt three-rotor unmanned aerial vehicle fault: Theory and experiments; page number: 1-9).
To sum up, the control problem of three-rotor drones has achieved some success, but few researchers consider its fault-tolerant control problem. To small-size rotor unmanned aerial vehicle's fault-tolerant control design, there is still certain restriction at present: 1) some control designs simplify the unmanned aerial vehicle dynamics model into a linear model, and although a more complex high-performance algorithm is designed, the strategies are generally difficult to be directly realized on a real unmanned aerial vehicle because a nonlinear part is ignored; 2) some fault tolerant control strategies use an observer-based approach to achieve fault diagnosis and then design dynamic control strategies to compensate. Although the method can effectively deal with various faults, the fault diagnosis effect can directly influence the control effect, so that the controller excessively depends on the diagnosis information, and the time delay from the occurrence of the fault to the fault diagnosis can be amplified on the high-instantaneity unmanned aerial vehicle system; 3) a controller is designed by considering external disturbance, model uncertainty and faults aiming at a nonlinear model of the unmanned aerial vehicle in a few methods; 4) at present, most fault-tolerant control methods only use numerical simulation for experimental verification, and few control designs are used for semi-physical or full-freedom platform experiments.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention comprehensively considers the external unknown disturbance and the model uncertainty aiming at the tail steering engine fault of the tilting three-rotor unmanned aerial vehicle. A nonlinear fault-tolerant control algorithm which does not need fault diagnosis, is robust and is high in feasibility is designed, and stable control over attitude motion is achieved under the condition that the tilting three-rotor unmanned aerial vehicle has tail steering engine blocking faults. The invention adopts the technical scheme that based on a self-adaptive backstepping method and terminal sliding mode control, the self-adaptive robust fault-tolerant control method of the tilting type three-rotor unmanned aerial vehicle is disclosed, and comprises the following steps:
1) establishing a fault model of the tilting three-rotor unmanned aerial vehicle:
defining two coordinate systems including an inertial coordinate system { E } and a body coordinate system { B }, selecting any point on the ground as an origin of the inertial coordinate system { E }, selecting the center of mass of the unmanned aerial vehicle as the origin of the body coordinate system { B }, and respectively defining { E } according to a right-hand rulex，Ey，EzAnd { B }x，By，BzThe attitude of the unmanned aerial vehicle can be obtained according to the Euler equation by using a dynamic model of the unmanned aerial vehicle as a reference coordinate axis in an inertial coordinate system (E) and a body coordinate system (B)
The kinematic model is
Wherein ω (t) ═ ωφ(t)，ωθ(t)，ωψ(t)]TFor the angular velocity vector of the drone relative to { E } under { B }, η (t) ═ phi (t), theta (t), psi (t)]TIs an attitude angle vector, J { [ Diag { [ J { ] { [x，Jy，Jz]TIs the moment of inertia matrix, τ (t) ═ τφ(t)，τθ(t)，τψ(t)]TTo control input torque, d (t) e R3×1For external disturbance vector, N (omega, η) is belonged to R3×1R (η) is an angular velocity transfer matrix expressing an angular velocity vector omega (t) and Euler angular velocity under { B }, and is a model uncertainty vector
In relation to each other, R (η) is specifically expressed as
For convenience of analysis, formula (1) is rewritten as
Where S (-) denotes an antisymmetric matrix spanned by a vector, i.e. for vector ω (t) [. omega. ]φ(t)，ωθ(t)，ωψ(t)]TS (omega) is
ρ (t) ═ d (t) + N (ω, η) is the perturbation and uncertainty term.
ρ (t) is unknown, but it satisfies the inequality,
||ρ(t)||＜b0+b1||η||+b2||ω||2(6)
wherein b is0，b1，b2They are all normal numbers.
The formula (4) is simplified into
Wherein G (omega) is an auxiliary variable, and the specific expression is
The moment-lift model of the tilting type three-rotor unmanned aerial vehicle is
Wherein l1，l2，l3Is a normal number, α (t) represents the tail steering engine inclination angle, fi(t), i is 1, 2, 3 is the lift force generated by each of the three motors, and defines a lift vector f (t) f1(t)，f2(t)，f3(t)]TAnd k is the ratio between the lift coefficient and the reaction torque coefficient, and satisfies the following conditions:
μi＝kfi，i＝1，2，3。 (10)
wherein mui(t), i is 1, 2 and 3 are reaction torques generated by the three motors respectively;
the variation range of the steering engine inclination angle α (t) is within 8 degrees, so sin α (t) < cos α (t), and kf3sin α term is ignored, then equation (9) is rewritten as
τ＝A(α)f (11)
Wherein the auxiliary variable
When the unmanned aerial vehicle steering wheel has a blockage fault, the steering wheel can stop at a certain fixed position and is not changed any more, so that the fault is considered
Wherein, tfα (t) represents the steering engine input angle before the fault occurred, α, as the time of the fault occurrencefThe angle of the blocked position of the steering engine is an unknown constant, and the relation between the moment and the lift force after the fault occurs is obtained according to the formulas (11) and (12)
τ＝A(αf)f (13)
Wherein the auxiliary variable
Defining an auxiliary variable λ1＝l3cosαf，λ2＝kcosαf-l3sinαfThen, the formula (13) can be rewritten as
τ＝A(λ1，λ2)f (14)
Wherein the auxiliary variable
Due to αfAs an unknown constant,/3And k is a known constant, thus λ1And λ2Are also unknown constants. The formula (14) is substituted for the formula (7) to obtain the dynamic equation of the unmanned aerial vehicle after the fault occurs, wherein the dynamic equation is
For tilting type three-rotor unmanned aerial vehicle systems (15) and (2), under the condition that a tail steering engine is blocked and has an unknown quantity rho (t), designing a proper control input vector f (t) to enable an attitude angle η (t) of the unmanned aerial vehicle to converge to a target value;
2) designing a controller:
for the convenience of designing the controller, the following definitions are made:
x2＝ω-ξ (17)
wherein x is1And x1As an auxiliary variable, ηd(t)∈R3×1In order to be the target attitude angle vector,
and
ξ is a designed virtual control signal expressed as
Defining the nonsingular terminal sliding mode surface s (t) as follows:
wherein β { [ β { [ diag { [ 78 { ] { [1，β2，β3]TThe matrix is a normal number diagonal matrix, p and q are positive relatively prime odd integers, and satisfy:
1＜p/q＜2 (20)
design control input lift vector f (t) is
Wherein
Is A (lambda)1，λ2) Is expressed as
In formula (22)
And
are each lambda1And λ2An estimate of (d).
3) And (3) self-adaptation law design:
design of
And
is updated according to the law
Wherein sigma1And σ2Updating the gains for them.
To ensure
So that its determinant is not equal to 0, then one can obtain
To ensureAnd
the upper and lower bounds of the parameter estimation value are limited by adopting a projection operator, and auxiliary variables are definedAnd
the projection operator is introduced as follows:
wherein, _λand
respectively represent
And
lower and upper bounds.
The invention has the characteristics and beneficial effects that:
the invention aims at a tilting type three-rotor unmanned aerial vehicle influenced by external unknown disturbance and model uncertainty and researches the fault-tolerant control problem when a tail steering engine has a blockage fault. Through the analysis of the attitude dynamic characteristics of the tilting three-rotor unmanned aerial vehicle, a robust fault-tolerant control design is provided based on a self-adaptive backstepping method and nonsingular terminal sliding mode control. When the tail steering engine of the unmanned aerial vehicle has a blockage fault, the method realizes a better control effect on the attitude motion.
Description of the drawings:
fig. 1 is a schematic view of the coordinate system and drone of the present invention.
Fig. 2 is a block flow diagram of the present invention.
FIG. 3 is an experimental platform used in the present invention.
FIG. 4 is a diagram of experimental effects of attitude flight control, in which:
a is an attitude angle change curve;
b is a control input variation curve;
c is an adaptive value change curve;
d is the change curve of the motor speed.
Detailed Description
In order to overcome the defects of the prior art, the invention comprehensively considers the external unknown disturbance and the model uncertainty aiming at the tail steering engine fault of the tilting three-rotor unmanned aerial vehicle. A nonlinear fault-tolerant control algorithm which does not need fault diagnosis, is robust and is high in feasibility is designed, and stable control over attitude motion is achieved under the condition that the tilting three-rotor unmanned aerial vehicle has tail steering engine blocking faults. The invention adopts the technical scheme that based on a self-adaptive backstepping method and terminal sliding mode control, the self-adaptive robust fault-tolerant control method of the tilting type three-rotor unmanned aerial vehicle is disclosed, and comprises the following steps:
1) establishing a fault model of the tilting three-rotor unmanned aerial vehicle:
two coordinate systems are defined, including an inertial coordinate system { E } and a volumetric coordinate system { B }. Selecting any point on the ground as the origin of an inertial coordinate system { E }, selecting the center of mass of the unmanned aerial vehicle as the origin of a body coordinate system { B }, and respectively defining { E } according to the right-hand rulex，Ey，EzAnd { B }x，By，BzAnd the coordinate axes are reference coordinate axes in an inertial coordinate system { E } and a body coordinate system { B }. The dynamical model of the unmanned aerial vehicle attitude can be obtained according to the Euler equation
The kinematic model is
Wherein ω (t) ═ ωφ(t)，ωθ(t)，ωψ(t)]TFor the angular velocity vector of the drone relative to { E } under { B }, η (t) ═ phi (t), theta (t), psi (t)]TIs an attitude angle vector, J { [ Diag { [ J { ] { [x，Jy，Jz]TIs the moment of inertia matrix, τ (t) ═ τφ(t)，τθ(t)，τψ(t)]TTo control input torque, d (t) e R3×1For external disturbance vector, N (omega, η) is belonged to R3×1R (η) is an angular velocity transfer matrix expressing an angular velocity vector omega (t) and Euler angular velocity under { B }, and is a model uncertainty vector
In relation to each other, R (η) is specifically expressed as
For convenience of analysis, formula (1) is rewritten as
Where S (-) denotes an antisymmetric matrix spanned by a vector, i.e. for vector ω (t) [. omega. ]φ(t)，ωθ(t)，ωψ(t)]TS (omega) is
ρ (t) ═ d (t) + N (ω, η) is the perturbation and uncertainty term.
Let us assume that ρ (t) is unknown, but that it satisfies the inequality,
||ρ(t)||＜b0+b1||η||+b2||ω||2(6)
wherein b is0，b1，b2They are all normal numbers.
The formula (4) is simplified into
Wherein G (omega) is an auxiliary variable, and the specific expression is
The moment-lift model of the tilting type three-rotor unmanned aerial vehicle is
Wherein l1，l2，l3Is a normal number, α (t) represents the tail steering engine inclination angle, fi(t), i is 1, 2, 3 is the lift force generated by each of the three motors, and defines a lift vector f (t) f1(t)，f2(t)，f3(t)]TAnd k is the ratio between the lift coefficient and the reaction torque coefficient, and satisfies the following conditions:
μi＝kfi，i＝1，2，3。 (10)
wherein muiAnd (t), i is equal to 1, 2 and 3 is the reaction torque generated by the three motors respectively.
The tilt angle α (t) of the tilting type three-rotor unmanned aerial vehicle researched by the invention has small change under the normal condition, and the change range is within 8 degrees, so sin α (t) <cos α (t)3sin α term is negligible, equation (9) can be rewritten as
τ＝A(α)f (11)
Wherein the auxiliary variable
When the unmanned aerial vehicle steering wheel has a blockage fault, the steering wheel can stop at a certain fixed position and is not changed any more, so that the fault is considered
Wherein, tfα (t) represents the steering engine input angle before the fault occurred, α, as the time of the fault occurrencefThe angle of the steering engine blockage position is an unknown constant. According to the equations (11) and (12), the relationship between the moment and the lift force after the failure is obtained
τ＝A(αf)f (13)
Wherein the auxiliary variable
Defining an auxiliary variable λ1＝l3cosαf，λ2＝kcosαf-l3sinαfThen, the formula (13) can be rewritten as
τ＝A(λ1，λ2)f (14)
Wherein the auxiliary variable
Due to αfAs an unknown constant,/3And k is a known constant, thus λ1And λ2Are also unknown constants. The formula (14) is substituted for the formula (7) to obtain the dynamic equation of the unmanned aerial vehicle after the fault occurs, wherein the dynamic equation is
Based on the analysis of the system dynamics characteristics and the expression of the steering engine faults, the control target of the invention is to design a proper control input vector f (t) for tilting type three-rotor unmanned aerial vehicle systems (15) and (2) under the condition that the tail steering engine is blocked and has unknown quantity rho (t), so that the attitude angle η (t) of the unmanned aerial vehicle converges to a target value.
2) Designing a controller:
for the convenience of designing the controller, the following definitions are made:
x2＝ω-ξ (17)
wherein x is1And x1As an auxiliary variable, ηd(t)∈R3×1In order to be the target attitude angle vector,
and
ξ is a designed virtual control signal expressed as
Reference (19), defines the nonsingular terminal sliding mode surface s (t) as follows:
wherein β { [ β { [ diag { [ 78 { ] { [1，β2，β3]TThe matrix is a normal number diagonal matrix, p and q are positive relatively prime odd integers, and satisfy:
1＜p/q＜2 (20)
design control input lift vector f (t) is
Wherein
Is A (lambda)1，λ2) Is expressed as
In formula (22)
And
are each lambda1And λ2An estimate of (d).
3) And (3) self-adaptation law design:
design ofAnd
is updated according to the law
Wherein sigma1And σ2Updating the gains for them.
To ensure
So that its determinant is not equal to 0, then one can obtain
To ensure
And
the upper and lower bounds of the parameter estimation value are limited by adopting a projection operator, and auxiliary variables are defined
And
the projection operator is introduced as follows:
wherein, iλand
respectively represent
And
lower and upper bounds.
The design of the fault-tolerant control method for the tail steering engine blocking fault of the tilting three-rotor unmanned aerial vehicle is finished.
The invention aims to solve the technical problem of providing a robust fault-tolerant control method, which realizes stable control of attitude motion under the condition that a tail steering engine of a tilting three-rotor unmanned aerial vehicle has a blockage fault.
The flow chart of the invention is shown in figure 2, and the technical scheme is as follows: a tilting three-rotor unmanned aerial vehicle tail steering engine blockage fault model is established, a robust fault-tolerant controller and a self-adaption law thereof are designed based on a self-adaption backstepping method and terminal sliding mode control, and the method comprises the following steps:
1) establishing a fault model of the tilting three-rotor unmanned aerial vehicle:
two coordinate systems are defined, including an inertial coordinate system { E } and a volumetric coordinate system { B }. Selecting any point on the ground as the origin of an inertial coordinate system { E }, selecting the center of mass of the unmanned aerial vehicle as the origin of a body coordinate system { B }, and respectively defining { E } according to the right-hand rulex，Ey，EzAnd { B }x，By，BzAnd the coordinate axes are reference coordinate axes in an inertial coordinate system { E } and a body coordinate system { B }. The dynamical model of the unmanned aerial vehicle attitude can be obtained according to the Euler equation
The kinematic model is
Wherein ω (t) ═ ωφ(t)，ωθ(t)，ωψ(t)]TFor the angular velocity vector of the drone relative to { E } under { B }, η (t) ═ phi (t), theta (t), psi (t)]TIs an attitude angle vector, J { [ Diag { [ J { ] { [x，Jy，Jz]TIs the moment of inertia matrix, τ (t) ═ τφ(t)，τθ(t)，τψ(t)]TTo control input torque, d (t) e R3×1For external disturbance vector, N (omega, η) is belonged to R3×1R (η) is an angular velocity transfer matrix expressing an angular velocity vector omega (t) and Euler angular velocity under { B }, and is a model uncertainty vector
In relation to each other, R (η) is specifically expressed as
For convenience of analysis, formula (1) is rewritten as
Where S () denotes an antisymmetric matrix spanned by the vectors, i.e. for a vector ω (t) — [ ω ·φ(t)，ωθ(t)，ωψ(t)]TS (omega) is
ρ (t) ═ d (t) + N (ω, η) is the perturbation and uncertainty term.
Let us assume that ρ (t) is unknown, but that it satisfies the inequality,
||ρ(t)||＜b0+b1||η||+b2||ω||2(6)
wherein b is0，b1，b2They are all normal numbers.
The formula (4) is simplified into
Wherein G (omega) is an auxiliary variable, and the specific expression is
The moment-lift model of the tilting type three-rotor unmanned aerial vehicle is
Wherein l1，l2，l3Is a normal number, α (t) represents the tail steering engine inclination angle, fi(t), i is 1, 2, 3 is the lift force generated by each of the three motors, and defines a lift vector f (t) f1(t)，f2(t)，f3(t)]TAnd k is the ratio between the lift coefficient and the reaction torque coefficient, and satisfies the following conditions:
μi＝kfi，i＝1，2，3。 (10)
wherein muiAnd (t), i is equal to 1, 2 and 3 is the reaction torque generated by the three motors respectively.
The tilt angle α (t) of the tilting type three-rotor unmanned aerial vehicle researched by the invention has small change under the normal condition, and the change range is within 8 degrees, so sin α (t) <cos α (t)3sin α term is negligible, equation (9) can be rewritten as
τ＝A(α)f (11)
Wherein the auxiliary variable
When the unmanned aerial vehicle steering wheel has a blockage fault, the steering wheel can stop at a certain fixed position and is not changed any more, so that the fault is considered
Wherein, tfα (t) represents the steering engine input angle before the fault occurred, α, as the time of the fault occurrencefThe angle of the steering engine blockage position is an unknown constant. According to the equations (11) and (12), the relationship between the moment and the lift force after the failure is obtained
τ＝A(αf)f (13)
Wherein the auxiliary variable
Defining an auxiliary variable λ1＝l3cosαf，λ2＝kcosαf-l3sinαfThen, the formula (13) can be rewritten as
τ＝A(λ1，λ2)f (14)
Wherein the auxiliary variable
Due to αfAs an unknown constant,/3And k is a known constant, thus λ1And λ2Are also unknown constants. The formula (14) is substituted for the formula (7) to obtain the dynamic equation of the unmanned aerial vehicle after the fault occurs, wherein the dynamic equation is
Based on the analysis of the system dynamics characteristics and the expression of the steering engine faults, the control target of the invention is to design a proper control input vector f (t) for tilting type three-rotor unmanned aerial vehicle systems (15) and (2) under the condition that the tail steering engine is blocked and has unknown quantity rho (t), so that the attitude angle η (t) of the unmanned aerial vehicle converges to a target value.
2) Designing a controller:
for the convenience of designing the controller, the following definitions are made:
x2＝ω-ξ (17)
wherein x is1And x1As an auxiliary variable, ηd(t)∈R3×1In order to be the target attitude angle vector,
and
ξ is a designed virtual control signal expressed as
Reference (19), defines the nonsingular terminal sliding mode surface s (t) as follows:
wherein β { [ β { [ diag { [ 78 { ] { [1，β2，β3]TThe matrix is a normal number diagonal matrix, p and q are positive relatively prime odd integers, and satisfy:
1＜p/q＜2 (20)
design control input lift vector f (t) is
Wherein
Is A (lambda)1，λ2) Is expressed as
In formula (22)
And
are each lambda1And λ2An estimate of (d).
3) And (3) self-adaptation law design:
design of
And
is updated according to the law
Wherein sigma1And σ2Updating the gains for them.
To ensure
So that its determinant is not equal to 0, then one can obtain
To ensure
And
the upper and lower bounds of the parameter estimation value are limited by adopting a projection operator, and auxiliary variables are defined
And
the projection operator is introduced as follows:
wherein, iλand
respectively represent
And
lower and upper bounds.
In order to verify the effectiveness of the fault-tolerant control method designed by the invention, experimental verification is carried out by utilizing a tilting type three-rotor unmanned aerial vehicle platform independently developed by a subject group. The invention provides a method for controlling the attitude of a tilting three-rotor unmanned aerial vehicle, which is described in detail in the following by combining experiments and accompanying drawings.
Brief introduction to the Experimental platform
The experimental platform is shown in fig. 3. The experimental platform adopts a PC/104 embedded computer as a simulation controller, an xPC target based on a Matlab RTW tool box as a real-time simulation environment, an autonomously designed inertia measurement unit as an attitude sensor, and the measurement precision of a pitch angle and a roll angle is +/-0.5 degrees. The yaw angle measurement accuracy is ± 2.0 °. The control frequency of the whole system is 500 Hz.
Second, attitude flight control experiment
The control strategy proposed by the present invention was validated using the experimental platform as described above. The relevant parameters of the unmanned aerial vehicle and the controller are selected as follows: j { [0.01, 0.015, 0.008 { [ diag { ] { [0.01, 0.015, 0.008 { ]]T}kg·m2，l1＝0.14m，l2＝0.08m，l3＝0.2m，k＝0.05，c1＝diag{[1.2，1.1，1.0]T}，c2＝diag{[9.63，2.64，1.22]T}，β＝diag{[0.1，0.1，0.1]T}，p＝5，q＝3，b0＝8，b1＝5，b2＝3，σ1＝0.11，σ2Target attitude angle set to η ═ 0.04d＝[0，0，0]TArtificially fixing the tilting angle of the steering engine at-2.5 degrees in the 30 th second to simulate the blockage fault of the steering engine, namely tf＝30s，αf＝-2.5°。
Fig. 4(a) shows the attitude angle curve of the drone. As can be seen from the figure, when the unmanned aerial vehicle has not failed in the first 30 seconds, the attitude angle error is small, the control accuracy of the roll angle and the pitch angle is within +/-0.5 degrees, and the control accuracy of the yaw angle is within +/-1 degree. At 30 seconds, the steering engine has a blockage fault, although the attitude angle fluctuates, the unmanned aerial vehicle can still keep stable flight, the control accuracy of the roll angle and the pitch angle is kept within +/-1 degree, and the control accuracy of the yaw angle is kept within +/-2.5 degrees. Fig. 4(b) is a control input curve, and it can be seen from the lift curve of the three rotors that some corresponding changes in the control input occur after the 30 th second failure, and then the control input is maintained within a certain range. The inclination angle of the steering engine still participates in control when the fault does not occur yet, the inclination angle is adjusted within a certain range, and the inclination angle is kept at-2.5 degrees after the fault occurs when the blockage of the steering engine. FIG. 4(c) is an adaptive value
And
all converge to a constant value after stabilization. Fig. 4(d) is a graph of the actual rotational speed of the motor, which can be seen to be maintained within a reasonable range. Based on the above results, it is proved that the method provided by the invention has a better fault-tolerant control effect.
Claims (1)
1. A self-adaptive robust fault-tolerant control method of a tilting type three-rotor unmanned aerial vehicle is characterized by comprising the following steps:
1) establishing a fault model of the tilting three-rotor unmanned aerial vehicle:
defining two coordinate systems including an inertial coordinate system { E } and a body coordinate system { B }, selecting any point on the ground as an origin of the inertial coordinate system { E }, selecting the center of mass of the unmanned aerial vehicle as the origin of the body coordinate system { B }, and respectively defining { E } according to a right-hand rulex,Ey,EzAnd { B }x,By,BzThe coordinate axes are reference coordinate axes in an inertial coordinate system (E) and a body coordinate system (B), and the reference coordinate axes are determined according to the Euler equationThe dynamic model of the unmanned aerial vehicle attitude can be obtained as
The kinematic model is
Wherein ω (t) ═ ωφ(t),ωθ(t),ωψ(t)]TFor the angular velocity vector of the drone relative to { E } under { B }, η (t) ═ phi (t), theta (t), psi (t)]TIs an attitude angle vector, J { [ Diag { [ J { ] { [x,Jy,Jz]TIs the moment of inertia matrix, τ (t) ═ τφ(t),τθ(t),τψ(t)]TTo control input torque, d (t) e R3×1For external disturbance vector, N (omega, η) is belonged to R3×1For model uncertainty vector, R (η) is angular velocity transfer matrix, which expresses angular velocity vector ω (t) and Euler angular velocity under { B }In relation to each other, R (η) is specifically expressed as
For convenience of analysis, formula (1) is rewritten as
Where S (-) denotes an antisymmetric matrix spanned by a vector, i.e. for vector ω (t) [. omega. ]φ(t)，ωθ(t)，ωψ(t)]TS (omega) is
ρ (t) ═ d (t) + N (ω, η) is the perturbation and uncertainty term,
ρ (t) is unknown, but it satisfies the inequality,
‖ρ(t)‖<b0+b1‖η‖+b2‖ω‖2(6)
wherein b is0，b1，b2Are all normal numbers, and are all positive numbers,
the formula (4) is simplified into
Wherein G (omega) is an auxiliary variable, and the specific expression is
The moment-lift model of the tilting type three-rotor unmanned aerial vehicle is
Wherein l1，l2，l3Is a normal number, α (t) represents the tail steering engine inclination angle, fi(t), i is 1, 2, 3 is the lift force generated by each of the three motors, and defines a lift vector f (t) f1(t),f2(t),f3(t)]TAnd k is the ratio between the lift coefficient and the reaction torque coefficient, and satisfies the following conditions:
μi＝kfi， (10)
wherein mui(t) reaction torques respectively generated by the three motors;
the variation range of the steering engine inclination angle α (t) is 8°Hence sin α (t)<<cos α (t), and kf3sin α term is ignored, then equation (9) is rewritten as
τ＝A(α)f (11)
Wherein the auxiliary variable
When the unmanned aerial vehicle steering wheel has a blockage fault, the steering wheel can stop at a certain fixed position and is not changed any more, so that the fault is considered
Wherein, tfα (t) represents the steering engine input angle before the fault occurred, α, as the time of the fault occurrencefThe angle of the blocked position of the steering engine is an unknown constant, and the relation between the moment and the lift force after the fault occurs is obtained according to the formulas (11) and (12)
τ＝A(αf)f (13)
Wherein the auxiliary variable
Defining an auxiliary variable λ1＝l3cosαf，λ2＝kcosαf-l3sinαfThen, the formula (13) can be rewritten as
τ＝A(λ1,λ2)f (14)
Wherein the auxiliary variable
Due to αfAs an unknown constant,/3And k is a known constant, thus λ1And λ2Are also unknown constants. The formula (14) is substituted for the formula (7) to obtain the dynamic equation of the unmanned aerial vehicle after the fault occurs, wherein the dynamic equation is
For tilting type three-rotor unmanned aerial vehicle systems (15) and (2), under the condition that a tail steering engine is blocked and has an unknown quantity rho (t), designing a proper control input vector f (t) to enable an attitude angle η (t) of the unmanned aerial vehicle to converge to a target value;
2) designing a controller:
for the convenience of designing the controller, the following definitions are made:
x2＝ω-ξ (17)
wherein x is1And x1As an auxiliary variable, ηd(t)∈R3×1In order to be the target attitude angle vector,
andξ is a designed virtual control signal expressed as
Defining the nonsingular terminal sliding mode surface s (t) as follows:
wherein β { [ β { [ diag { [ 78 { ] { [1,β2,β3]TThe matrix is a normal number diagonal matrix, p and q are positive relatively prime odd integers, and satisfy:
1<p/q<2 (20)
design control input lift vector f (t) is
Wherein
Is A (lambda)1，λ2) Is expressed as
In formula (22)
Andare each lambda1And λ2An estimated value of (d);
3) and (3) self-adaptation law design:
design of
Andis updated according to the law
Wherein sigma1And σ2Updating the gains for them.
To ensure
So that its determinant is not equal to 0, then one can obtain
To ensure
And
the upper and lower bounds of the parameter estimation value are limited by adopting a projection operator, and auxiliary variables are defined
Andthe projection operator is introduced as follows:
wherein, iλandrespectively represent
And
lower and upper bounds.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911197484.2A CN110824925A (en) | 2019-11-29 | 2019-11-29 | Adaptive robust fault-tolerant control method for tilting type three-rotor unmanned aerial vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911197484.2A CN110824925A (en) | 2019-11-29 | 2019-11-29 | Adaptive robust fault-tolerant control method for tilting type three-rotor unmanned aerial vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110824925A true CN110824925A (en) | 2020-02-21 |
Family
ID=69543124
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911197484.2A Pending CN110824925A (en) | 2019-11-29 | 2019-11-29 | Adaptive robust fault-tolerant control method for tilting type three-rotor unmanned aerial vehicle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110824925A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111580537A (en) * | 2020-05-28 | 2020-08-25 | 西北工业大学 | Unmanned aerial vehicle stunt flight control system and method |
| CN111880410A (en) * | 2020-08-11 | 2020-11-03 | 北京航空航天大学 | Four-rotor unmanned aerial vehicle fault-tolerant control method for motor faults |
| CN113156995A (en) * | 2021-04-25 | 2021-07-23 | 西安工业大学 | Unmanned helicopter attitude control method under actuator fault |
| CN113359473A (en) * | 2021-07-06 | 2021-09-07 | 天津大学 | Microminiature unmanned helicopter nonlinear control method based on iterative learning |
| CN113777932A (en) * | 2021-11-15 | 2021-12-10 | 南京信息工程大学 | Four-rotor self-adaptive sliding mode fault-tolerant control method based on Delta operator |
| CN116719332A (en) * | 2023-05-22 | 2023-09-08 | 四川大学 | Unmanned aerial vehicle position and posture regulation and control system and method based on tilting rotation wing |
| CN117518800A (en) * | 2023-11-10 | 2024-02-06 | 北京航空航天大学 | Robust self-adaptive control method and system for four-rotor unmanned aerial vehicle hanging load system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106647783A (en) * | 2016-11-22 | 2017-05-10 | 天津大学 | Tilting type tri-rotor unmanned aerial vehicle attitude and height adaptive robust control method |
| CN106842952A (en) * | 2017-03-08 | 2017-06-13 | 天津大学 | For the fault tolerant control method of three rotor wing unmanned aerial vehicle steering wheel plugging faults |
| CN109976367A (en) * | 2019-03-27 | 2019-07-05 | 天津大学 | For the attitude system control method of three rotor wing unmanned aerial vehicle of tilting type |
| CN110058600A (en) * | 2019-02-26 | 2019-07-26 | 天津大学 | The fault tolerant control method of pose system under three rotor wing unmanned aerial vehicle steering engine plugging faults |
-
2019
- 2019-11-29 CN CN201911197484.2A patent/CN110824925A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106647783A (en) * | 2016-11-22 | 2017-05-10 | 天津大学 | Tilting type tri-rotor unmanned aerial vehicle attitude and height adaptive robust control method |
| CN106842952A (en) * | 2017-03-08 | 2017-06-13 | 天津大学 | For the fault tolerant control method of three rotor wing unmanned aerial vehicle steering wheel plugging faults |
| CN110058600A (en) * | 2019-02-26 | 2019-07-26 | 天津大学 | The fault tolerant control method of pose system under three rotor wing unmanned aerial vehicle steering engine plugging faults |
| CN109976367A (en) * | 2019-03-27 | 2019-07-05 | 天津大学 | For the attitude system control method of three rotor wing unmanned aerial vehicle of tilting type |
Non-Patent Citations (2)
| Title |
|---|
| SALAZAR-CRUZ S 等: "Real-time stabilization of a small three-rotor aircraft", 《IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS》 * |
| 王栋 等: "倾转式三旋翼无人机的自适应鲁棒容错控制", 《道客巴巴》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111580537A (en) * | 2020-05-28 | 2020-08-25 | 西北工业大学 | Unmanned aerial vehicle stunt flight control system and method |
| CN111880410A (en) * | 2020-08-11 | 2020-11-03 | 北京航空航天大学 | Four-rotor unmanned aerial vehicle fault-tolerant control method for motor faults |
| CN111880410B (en) * | 2020-08-11 | 2021-12-28 | 北京航空航天大学 | Four-rotor unmanned aerial vehicle fault-tolerant control method for motor faults |
| CN113156995A (en) * | 2021-04-25 | 2021-07-23 | 西安工业大学 | Unmanned helicopter attitude control method under actuator fault |
| CN113359473A (en) * | 2021-07-06 | 2021-09-07 | 天津大学 | Microminiature unmanned helicopter nonlinear control method based on iterative learning |
| CN113359473B (en) * | 2021-07-06 | 2022-03-11 | 天津大学 | Microminiature unmanned helicopter nonlinear control method based on iterative learning |
| CN113777932A (en) * | 2021-11-15 | 2021-12-10 | 南京信息工程大学 | Four-rotor self-adaptive sliding mode fault-tolerant control method based on Delta operator |
| CN116719332A (en) * | 2023-05-22 | 2023-09-08 | 四川大学 | Unmanned aerial vehicle position and posture regulation and control system and method based on tilting rotation wing |
| CN116719332B (en) * | 2023-05-22 | 2024-01-30 | 四川大学 | Unmanned aerial vehicle position and posture regulation and control system and method based on tilting rotor |
| CN117518800A (en) * | 2023-11-10 | 2024-02-06 | 北京航空航天大学 | Robust self-adaptive control method and system for four-rotor unmanned aerial vehicle hanging load system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110824925A (en) | Adaptive robust fault-tolerant control method for tilting type three-rotor unmanned aerial vehicle | |
| Hou et al. | Nonsingular terminal sliding mode control for a quadrotor UAV with a total rotor failure | |
| Wang et al. | Robust H∞ attitude tracking control of a quadrotor UAV on SO (3) via variation-based linearization and interval matrix approach | |
| Islam et al. | Robust control of four-rotor unmanned aerial vehicle with disturbance uncertainty | |
| CN105911866B (en) | Finite time full-order sliding mode control method of four-rotor unmanned aerial vehicle | |
| Labbadi et al. | Novel robust super twisting integral sliding mode controller for a quadrotor under external disturbances | |
| Gonzalez-Vazquez et al. | A new nonlinear PI/PID controller for quadrotor posture regulation | |
| Tang et al. | Nonlinear dynamic modeling and hybrid control design with dynamic compensator for a small-scale UAV quadrotor | |
| CN108445895A (en) | Robust control method for the control of three rotor wing unmanned aerial vehicle position of tilting type | |
| CN110058600B (en) | Fault-tolerant control method for pose system under three-rotor unmanned aerial vehicle steering engine blocking fault | |
| CN108490780A (en) | A kind of quadrotor drone wide-angle complexity Attitude tracking control method of low-power consumption | |
| CN114063447B (en) | Double-tilt rotor unmanned aerial vehicle mode transition control method based on dynamics analysis | |
| Kumar et al. | Quaternion feedback based autonomous control of a quadcopter uav with thrust vectoring rotors | |
| Sharma et al. | Nonlinear disturbance observer based geometric control of quadrotors | |
| Sanwale et al. | Robust fault-tolerant adaptive integral dynamic sliding mode control using finite-time disturbance observer for coaxial octorotor UAVs | |
| CN115202213A (en) | Four-rotor aircraft control method based on active disturbance rejection control | |
| Qin et al. | Gemini ii: Design, modeling, and control of a compact yet efficient servoless bi-copter | |
| CN111338369A (en) | Multi-rotor flight control method based on nonlinear inverse compensation | |
| Akbar et al. | Adaptive modified super-twisting control for a quadrotor helicopter with a nonlinear sliding surface | |
| Cheng et al. | Finite time fault tolerant control design for UAV attitude control systems with actuator fault and actuator saturation | |
| BOUZID et al. | Generic dynamic modeling for multirotor VTOL UAVs and robust Sliding Mode based Model-Free Control for 3D navigation | |
| Mosalsal et al. | Variable pitch control of a quadrotor using adaptive sliding mode controller | |
| Zou et al. | Singularity-free backstepping controller for model helicopters | |
| CN116954240A (en) | Anti-saturation and anti-interference position and posture tracking control method for four-rotor unmanned aerial vehicle | |
| CN116430828A (en) | Four-rotor fault disaster recovery degradation control method based on observer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200221 |
|
| WD01 | Invention patent application deemed withdrawn after publication |