Abstract
The attitude control system design for an unmanned helicopter is always a challenging task because the vehicle dynamics are highly nonlinear and fully coupled and subject to parametric uncertainties. This paper presents an adaptive attitude tracking controller with dual model structure, which achieves significant tracking performance and has good capability to overcome the adverse effect of measurement noises on the convergence of adjustable parameters. Moreover, a modified controller with variable gain elements is designed to further reduce the adverse effect of measurement noises on the adjustable system output in the later stage of the adaptive learning process. A series of hardware-in-loop simulations have verified the proposed adaptive control schemes. The suggested design methodologies featured in this paper are effective control tools that can help bridge the gaps between adaptive control theory and the need of realistic applications such as high-performance unmanned helicopters.
Similar content being viewed by others
Abbreviations
- A :
-
system matrix
- A q̇ p A q̇ r :
-
system matrices of adjustable system and reference model about the trim state, respectively
- B :
-
operating frequency range, Hz
- B :
-
control-input matrix
- B q̇ p B q̇ r :
-
control-input matrices of adjustable system and reference model about the trim state, respectively
- C m :
-
sensitivity coefficient
- D :
-
variance
- e, e f :
-
tracking error θ m -θ and its filtered version, deg
- e f 0 :
-
noise-free part of e f
- e r :
-
tracking error θ r -θ, deg
- e q̇ f :
-
state error vector with filters
- E :
-
expectation
- E :
-
unknown equivalent trim disturbance vector
- G d :
-
transfer function of linear compensator
- G e :
-
transfer function of error compensator
- G f :
-
transfer function of filter
- G m :
-
transfer function of tracking model
- G p :
-
transfer function of adjustable system
- G r :
-
transfer function of reference model
- M q̇• :
-
aerodynamic parameter
- M q̇* :
-
aerodynamic parameter vector
- k c , k q , k θ :
-
adjustable parameters
- k ci , k qi , k ui , k θi :
-
learning coefficients of adjustable parameters
- k a c , k a q , k a θ :
-
modified versions of adjustable parameters
- k e c , k e q , k e θ :
-
modified versions of adjustable parameters
- k e :
-
variable gain element
- \(\widehat k\) θi :
-
modified version of learning coefficient k θ
- K ci , K qi , K θi :
-
positive integral kernels
- K cp , K qp , K θp :
-
nonnegative functions
- K * :
-
adjustable parameter vector
- p, q, r :
-
roll, pitch and yaw rates linearized about the trim state, deg/s
- \(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{p} ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{q} ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{r} \) :
-
roll, pitch and yaw rates, deg/s
- u, v, w :
-
forward, lateral and vertical velocities linearized about the trim state, m/s
- \(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{u} ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{v} ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{w} \) :
-
forward, lateral and vertical velocities, m/s
- u q̇ :
-
input vector
- \(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{U} ,U\), U :
-
system input and its linearized version about the trim state
- U e , U 0 :
-
trim input and nominal trim input
- x q̇ p ,x q̇ r :
-
state vectors of reference model and adjustable system, respectively
- \(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{X} ,X\), X :
-
state vector and its linearized version about the trim state
- X e , X 0 :
-
trim state and nominal trim state
- δ e , δ a , δ r , δ c :
-
pitch cyclic, roll cyclic, tail rotor collective and main rotor collective linearized about the trim state, deg
- \(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\delta } _e ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\delta } _a ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\delta } _r ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\delta } _c \) :
-
pitch cyclic, roll cyclic, tail rotor collective and main rotor collective, respectively, deg
- δ ea , δ ef :
-
adjustable system input signal and its filtered version
- δ ec :
-
manipulated input signal
- δ ee , δ em :
-
outputs of G e in response to θ, θ m , respectively
- \({\overline \delta _*}\) :
-
equivalent disturbance
- \({\widetilde \delta _*}\) :
-
equivalent external disturbance
- \({\widehat \delta _*}\) :
-
compensation signal for compensating for \({\widetilde \delta _*}\)
- δ * :
-
coupled disturbance vector
- δ *f :
-
filtered version of δ *
- ∆ θf , ∆ qf :
-
optional positive threshold values
- ε f :
-
output of G d in response to θ rf - θ f
- ε f0 :
-
noise-free part of ε f
- ε u , ε x :
-
estimate errors of U e , X e , respectively
- η :
-
unknown equivalent trim disturbance
- λ c , λ e , λ q , λ q :
-
optional positive constants
- θ, ϕ, ψ :
-
pitch, roll and yaw angles linearized about the trim state, deg
- \(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\theta } ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\varphi } ,\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\psi } \) :
-
pitch, roll and yaw angles, deg
- θ 0, \({\dot \theta _0}\) :
-
noise-free parts of θ, \({\dot \theta _0}\), respectively
- θ f :
-
filtered version of θ
- θ f0, \({\dot \theta _{f0}}\) :
-
noise-free parts of θ f , \({\dot \theta _f}\), respectively
- θ m :
-
tracking model output
- θ rf :
-
output of reference model with filter
- Θ:
-
aerodynamic parameter set
- τ :
-
time window width
- τ qe , τ θe :
-
differential and proportional coefficients of G e
- ω m :
-
natural frequency, rad/s
- \({\xi _{{\varepsilon _f}}}\) :
-
mixed noise in ε f
- ξ θ , ξ q :
-
measurement noises in θ, \(\dot \theta \), respectively
- \({\xi _{{\theta _f}}}\), ξ qf :
-
filtered versions of ξ θ , ξ q
- ζ m :
-
damping ratio
References
M. Ekblad, “Reduced-order modeling and controller design for a high performance helicopter,” Journal of Guidance, Control, and Dynamics, vol. 13, no. 3, pp. 439–449, May-June 1990. [click]
R. A. Hess and P. J. Gorder, “Quantitative feedback theory applied to the design of a rotorcraft flight control system,” Journal of Guidance, Control, and Dynamics, vol. 16, no. 4, pp. 748–753, July-August 1993. [click]
E. Low and W. L. Garrard, “Design of flight control systems to meet rotorcraft handling qualities specications,” Journal of Guidance, Control, and Dynamics, vol. 16, no. 1, pp. 69–78, January-February 1993. [click]
I. A. Raptis, P. Kimon and J. V. George, “Linear tracking control for small-scale unmanned helicopters,” IEEE Transactions on Control Systems Technology, vol. 20, no. 4, pp. 995–1010, July 2012. [click]
D. Lee, H. J. Kim, and S. Sastry, “Feedback linearization vs. adaptive sliding mode control for a quadrotor helicopter,” International Journal of Control, Automation and Systems, vol. 7, no. 3, pp.419–428, June 2009. [click]
K. Peng, G. Cai, B. M. Chen, et al., “Design and implementation of an autonomous flight control law for a UAV helicopter,” Automatica, vol. 45, no. 10, pp. 2333–2338, October 2009. [click]
J. A. Guerrero, R. Lozano, et al., “Robust control design based on sliding mode control for hover flight of a mini tailsitter unmanned aerial vehicle,” Proc. of Industrial Electronics, IECON’09, 35th Annual Conference of IEEE, pp. 2342–2347, November 2009. [click]
M. Tarek and A. Benallegue, “Back stepping control with exact 2-sliding mode estimation for a quad rotor unmanned aerial vehicle,” Proc. of Intelligent Robots and Systems, IEEE/RSJ International Conference on. IEEE, pp. 141–146, October 2007. [click]
S. Bouabdallah and R. Siegwart, “Backstepping and sliding-mode techniques applied to an indoor micro quad rotor,” Proc. IEEE Int. Conf. on Robotics and Automation, Barcelona, Spain, pp. 2259–2264, April 2005. [click]
H. Sira-Ramirez, M. Zribi and S. Ahmad, “Dynamical sliding mode control approach for vertical flight regulation in helicopters,” IEE Proceedings-Control Theory and Applications, vol. 141, no. 1, pp. 19–24, January 1994. [click]
E. Altug, J. P. Ostrowski and R. Mahony, “Control of a quad rotor helicopter using visual feedback,” Proc. IEEE Int. Conf. on Robotics and Automation, Washington, DC, pp. 72–77, May 2002. [click]
G. Cai, B. Wang, B. M. Chen, et al., “Design and implementation of a flight control system for an unmanned rotorcraft using RPT control approach,” Asian Journal of Control, vol. 15, no. 1, pp. 95–119, January 2013. [click]
H.-C. Kim, H. R. Dharmayanda, T. Kang, A. Budiyono, G. Lee, and W. Adiprawita, “Parameter identification and design of a robust attitude controller using H ∞ methodology for the raptor E620 small-scale helicopter,” International Journal of Control, Automation and Systems, vol. 10, no. 1, pp. 88–101, February 2012. [click]
G. Cai, B. M. Chen, X. Dong, et al., “Design and implementation of a robust and nonlinear flight control system for an unmanned helicopter,” Mechatronics, vol. 21, no. 5, pp. 803–820, August 2011. [click]
M. L. Civita, G. Papageorgiou, W. C. Messner, et al., “Design and flight testing of an H ∞ controller for a robotic helicopter,” Journal of Guidance, Control, and Dynamics, vol. 29, no. 2, pp. 485–494, March-April 2006. [click]
J. Shin, K. Nonami, D. Fujiwara, et al., “Model-based optimal attitude and positioning control of small-scale unmanned helicopter,” Robotica, vol. 23, no. 1, pp. 51–63, January 2005. [click]
E. N. Johnson and K. K. Suresh, “Adaptive flight control for an autonomous unmanned helicopter,” Proc. of AIAA Guidance, Navigation and Control Conference, vol. 11. Monterey, CA: AIAA, August 2002. [click]
S. Zein-Sabatto and Y. Zheng, “Intelligent flight controllers for helicopter control,” Proc. IEEE Int. Conf. on Neural Networks (Houston), pp. 617–621, June 1997. [click]
T. Dierks, and S. Jagannathan, “Online optimal control of affine nonlinear discrete-time systems with unknown internal dynamics by using time-based policy update,” Neural Networks and Learning Systems, IEEE Transactions on, vol. 23, no. 7, pp. 1118–1129, July 2012. [click]
M. S. Mahmoud and A. B. Koesdwiady, “Improved digital tracking controller design for pilot-scale unmanned helicopter,” Journal of the Franklin Institute, vol. 349, no. 1, pp. 42–58, February 2012. [click]
A. S. Krupadanam, A. M. Annaswamy, and R. S. Mangoubi, “Multivariable adaptive control design with applications to autonomous helicopters,” Journal of Guidance, Control, and Dynamics, vol. 25, no. 5, pp. 843–851, September - October 2002. [click]
A. S. Krupadanam, “A viable multivariable adaptive controller with application to autonomous helicopters,” Ph.D. Dissertation, Dept. of Mechanical Engineering, Massachusetts Inst. of Technology, Cambridge, MA, July 2001.
Y. Liu and G. Tao, “Modeling and model reference adaptive control of aircraft with asymmetric damage,” Journal of Guidance, Control, and Dynamics, vol. 33, no. 5, pp. 1500–1517, September-October 2010. [click]
Y. Shin, A. J. Calise and M. D. Johnson, “Adaptive control of advanced fighter aircraft in nonlinear flight regimes,” Journal of Guidance, Control, and Dynamics, vol. 31, no. 5, pp. 1464–1477, September-October 2008. [click]
S. A. Neild, L. Yang and D. J. Wagg, “A modified model reference adaptive control approach for systems with noise or unmodelled dynamics,” Proc. IMechE, Part I: J. Systems and Control Engineering, vol. 222, pp. 197–208, January 2008. [click]
B. Mettler, “Modeling small-scale unmanned rotorcraft for advanced flight control design,” Ph.D. Dissertation, Carnegie Mellon University, Pittsburgh, USA, 2001.
B. Mettler, Identification Modeling and Characteristics of Miniature Rotorcraft, Boom Koninklijke Uitgevers, Meppel, Netherlands, 2002. [click]
K. J. Åström, and B. Wittenmark, Adaptive Control, Dover Publications, NY, USA, 2013.
Author information
Authors and Affiliations
Corresponding author
Additional information
Recommended by Associate Editor Wen-Hua Chen under the direction of Editor Duk-Sun Shim. This work was sponsored by National Natural Science Foundation of China under Grant No. 61374188, Aeronautical Science Foundation of China under Grant No. 2013ZC52033, Natural Science Foundation of Jiangsu Province, China under Grant No. BK20141412, Applied Basic Research Programs of Natural Science Foundation of Jiangsu Province, China under Grant No. BY2015003-10.
Shouzhao Sheng received his PhD degree in Control Theory and Control Engineering from Nanjing University of Aeronautics and Astronautics in 2005. His research interests include flight control, adaptive control and system identification.
Chenwu Sun received his Bachelor degree in Control Engineering from Heilongjiang University in 2013. He is currently a PhD candidate in the College of Automation Engineering, Nanjing University of Aeronautics and Astronautics. His research interests include flight control and adaptive control.
Rights and permissions
About this article
Cite this article
Sheng, S., Sun, C. An adaptive attitude tracking control approach for an unmanned helicopter with parametric uncertainties and measurement noises. Int. J. Control Autom. Syst. 14, 217–228 (2016). https://doi.org/10.1007/s12555-014-0244-8
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12555-014-0244-8