Equation Chapter 1 Section 1
Abstract—A nonlinear robust control strategy for hypersonic
vehicle in tracking the responses to a step change in altitude
and airspeed is proposed. The vehicle model is nonlinear,
multivariable, unstable, and includes uncertain parameters.
Firstly, the analysis is conducted for the hypersonic vehicle
model via input-output (I/O) linearized technique. Secondly,
the sliding mode manifold is designed based on the
homogeneity theory. Then, the adaptive high order sliding
mode controller is proposed to achieve the tracking for
hypersonic vehicle with bounded uncertainty but its boundary
is not known in advance. Furthermore, the stability of the
system is proved via Lyapunov theory. Finally, the simulation
results are provided to demonstrate the effectiveness of the
proposed control strategy.
I. INTRODUCTION
The need for a reliable and cost-effective access to space
for both civilian and military applications has spurred a
renewed interest in hypersonic vehicle. A considerable effort
has been made by the U.S. Air Force and NASA to further
their development and design during the last decades.
Although the recent success of NASA’s X-43A experimental
vehicle, the design of control systems for hypersonic vehicles
is a challenging task due to the fact that the dynamics of
hypersonic vehicles is highly nonlinear, coupled and partly
unpredictable.
Many advance control methods based on robust and
adaptive theory have been extensively used to study the flight
control problem since 1990’s. Such as, Marrison
[1]
used
linear-quadratic stochastic robust control, while Wang
[2]
combined nonlinear dynamic inversion with stochastic
robustness to design the control system for hypersonic
vehicle. To provide robust velocity and altitude tracking in
the presence of parameter uncertainties and varying flight
conditions, the robust output-feedback control is designed in
Ref.[3]. Cliff
[4]
proposed the L1 adaptive control architecture
to compensate for parametric uncertainties and the
unmodeled dynamics for hypersonic vehicle. Thereafter, the
employed both robust and adaptive techniques on a
sequential loop closing methodology is proposed in Ref.[5].
In spite of the extensive development of robust control
methods, Sliding Mode Control (SMC) remains a key choice
for handling bounded uncertainties and unmodeled dynamics
in control problems. However, the pure sliding mode control
presents drawbacks that include large control authority
requirements and control chattering. Xu
[6]
combined the the
* This work has been supported by National Natural Science Foundation
of China (61203012, 61273092, 91016018), Key Grant Project of Chinese
Bailing Tian is with the School of Electric and Automation Engineering,
Tianjin University, Tianjin, China (e-mail: tianbailing121@126.com)
Wenru Fan is with Aeronautical Automation College, Civil Aviation
University of China, Tianjin, China (e-mail: wenrufan@tju.edu.cn).
estimator-based solution with the standard SMC to design an
adaptive sliding mode controller that avoids the chattering
phenomenon and tracks step commands in velocity and
altitude while requiring limited state information. Ronald
[7]
investigated a pseudo-sliding mode flight control design in
the frequency domain, based on the sliding mode control
theory. Furthermore, in order to improve the control
performance, the high order sliding mode control (HOSM)
strategy begins to be applied in flight control system for
hypersonic vehicle. The HOSM keeps the main advantages of
standard SMC, the chattering effect, relative degree
restriction are eliminated and higher order precision is
provided
[8,9]
. Zong proposed the quasi-continuous HOSM
controller for hypersonic cruise vehicle to achieve the track
for the responses to a step change in altitude and airspeed
[10]
.
Subsequently, the HOSM controller and observer are
synthesized to control the hypersonic vehicle with angle of
attack and flight path angle unmeasurable in Ref.[11].
Although many nonlinear control methods have been used in
hypersonic vehicle, the assumption that the boundary of
uncertainty is known in advance is often used in the design of
flight control. However, the boundary can’t be known exactly
in practical flight control system which makes the control
system design more challenging.
This paper is part of a continuing effort to develop
practical nonlinear robust control method for hypersonic
vehicle with bounded uncertainty but its boundary is not
known in advance. The paper is organized as follows: In Sec.
2 the hypersonic vehicle model is introduced and the control
objective is stated. The input-output decoupling linearization
model is derived for hypersonic vehicle via dynamic
inversion technique in Sec.3. In Sec.4, the adaptive
high-order sliding mode theory is proposed to design
controller to achieve stable tracking in altitude and velocity.
Finally, the simulation results are provided in Sec.5 to verify
the effectiveness of the proposed control strategy and this
paper ends with the conclusion remarks in Sec. 6.
II. PROBLEM FORMULATION
A. Hypersonic Vehicle Model
The longitudinal model of a generic hypersonic vehicle
under study is a conical vehicle designed by National
Aero-Space Plane Program. At the trimmed conditions
15060ft/s, 110000ft, =0.0315rad, 0rad, =0rad)V h q
(
, the
open-loop dynamics of the vehicle exhibits statically unstable
short-period mode, lightly damped phugoid mode as well as a
mildly unstable height mode
[12]
. Consequently, cruising flight
would be subject to attitude and velocity divergence that
would require stabilized feedback control. Force and moment
coefficients of the vehicle for different Mach numbers, angle
Adaptive High Order Sliding Mode Controller Design for
Hypersonic Vehicle*
Bailing Tian, Member IEEE, Member AIAA, Wenru Fan
2013 10th IEEE International Conference on Control and Automation (ICCA)
Hangzhou, China, June 12-14, 2013
978-1-4673-4708-2/13/$31.00 ©2013 IEEE 464