Chen Diao

Bio: Chen Diao is an academic researcher from Tianjin University. The author has contributed to research in topics: Lyapunov function & Control theory. The author has an hindex of 7, co-authored 14 publications receiving 360 citations. Previous affiliations of Chen Diao include Tianjin University of Technology.

Adaptive tracking control of underactuated quadrotor unmanned aerial vehicles via backstepping

Abstract: This paper considers about the control problem for an underactuated quadrotor UAV system with model parameter uncertainty. Backstepping based techniques are utilized to design a nonlinear adaptive controller which can compensate for the mass uncertainty of the vehicle. Lyapunov based stability analysis shows that the proposed control design yields asymptotic tracking for the UAV's motion in x, y, z direction and the yaw rotation, while keep the stability of the closed loop dynamics of the quadrotor UAV. Numerical simulation results are provided to show the good tracking performance of proposed control laws.

Nonlinear robust output feedback tracking control of a quadrotor UAV using quaternion representation

Abstract: In this paper, a new quaternion-based nonlinear robust output feedback tracking controller is developed to address the attitude and altitude tracking problem of a quadrotor unmanned aerial vehicle which is subject to structural uncertainties and unknown external disturbances By using the unit quaternion representation, the singularity associated with orientation representations can be avoided A set of non-model-based filters are introduced to provide estimations for the unmeasurable angular velocities and translational velocity in the altitude direction of the quadrotor in the case that velocity feedback is unavailable Approximation components based on neural network (NN) are introduced to estimate the modeling uncertainties, and robust feedback components are designed to compensate for external disturbances and NN reconstruction errors The Lyapunov-based stability analysis is employed to prove that a semiglobally asymptotic tracking result is achieved and all the closed-loop states remain bounded Numerical simulation results are provided to illustrate the good tracking performance of the proposed control methodologies

A nonlinear adaptive control approach for quadrotor UAVs

Abstract: In this paper, a continuous, time varying adaptive controller is developed for an underactuated quadrotor unmanned aerial vehicle (UAV). The vehicle's dynamic model is subject to uncertainties associated with mass, inertia matrix, and aerodynamic damping coefficients. A Lyapunov based approach is utilized to ensure that position and yaw rotation tracking errors are ultimately driven to a neighborhood about zero that can be made arbitrary small. Simulation results are included to illustrate the performance of the control strategy.

Output feedback control of hypersonic vehicles based on neural network and high gain observer

Abstract: In this paper, the output feedback control problem for a genetic hypersonic vehicle is considered under the restriction that only the vehicle’s velocity and altitude are measurable. High gain observers (HGO) are utilized to provide estimation signals for unmeasurable derivatives of the vehicle’s velocity and altitude. Neural network based feedforward function is designed to compensate for model uncertainties. The proposed control design require less knowledge of the hypersonic vehicle’s dynamic model. A comprehensive stability analysis of the closed loop system under the output feedback control is carried to prove that the proposed control law yields semiglobal uniformly ultimately bounded tracking while keeping all the closed loop signals bounded. Numerical simulation results are presented to validate the proposed control design.

Nonlinear adaptive regulation control of a quadrotor unmanned aerial vehicle

Abstract: In this paper, a nonlinear adaptive regulation controller is presented for a class of underactuated quadrotor unmanned aerial vehicle (UAV) The vehicle's dynamics is subject to modeling impression associated with the inertia matrix, aerodynamic damping coefficients, and some other system parameters The on-line parameter estimation scheme is combined with feedback control to develop the adaptive control laws Lyapunov based approaches are utilized to prove that the quadrotor UAV's position and yaw angle regulation errors are ultimately driven to zero under parametric uncertainties Simulation results are included to demonstrate the performance of the control strategy

An overview on flight dynamics and control approaches for hypersonic vehicles

Abstract: With the capability of high speed flying, a more reliable and cost efficient way to access space is provided by hypersonic flight vehicles. Controller design, as key technology to make hypersonic flight feasible and efficient, has numerous challenges stemming from large flight envelope with extreme range of operation conditions, strong interactions between elastic airframe, the propulsion system and the structural dynamics. This paper briefly presents several commonly studied hypersonic flight dynamics such as winged-cone model, truth model, curve-fitted model, control oriented model and re-entry motion. In view of different schemes such as linearizing at the trim state, input-output linearization, characteristic modeling, and back-stepping, the recent research on hypersonic flight control is reviewed and the comparison is presented. To show the challenges for hypersonic flight control, some specific characteristics of hypersonic flight are discussed and the potential future research is addressed with dealing with actuator dynamics, aerodynamic/reaction-jet control, flexible effects, non-minimum phase problem and dynamics interaction.

Nonlinear Control of Quadrotor for Point Tracking: Actual Implementation and Experimental Tests

Abstract: In this paper, a nonlinear control scheme along with its simulation and experimental results for a quadrotor are presented. It is not easy to control the quadrotor because the dynamics of quadrotor, which is obtained via the Euler–Lagrangian approach, has the features of underactuated, strongly coupled terms, uncertainty, and multiinput/multioutput. We propose a new nonlinear controller by using a backstepping-like feedback linearization method to control and stabilize the quadrotor. The designed controller is divided into three subcontrollers which are called attitude controller, altitude controller, and position controller. Stability of the designed controller is verified by the Lyapunov stability theorem. Detailed hardware parameters and experimental setups to implement the proposed nonlinear control algorithms are presented. The validity of proposed control scheme is demonstrated by simulations under different simulation scenarios. Experimental results show that the proposed controller is able to carry out the tasks of taking off, hovering, and positioning.

Finite time integral sliding mode control of hypersonic vehicles

Abstract: This study investigates the tracking control problem for the longitudinal model of an airbreathing hypersonic vehicle (AHV) with external disturbances. By introducing finite time integral sliding mode manifolds, a novel finite time control method is designed for the longitudinal model of an AHV. This control method makes the velocity and altitude track the reference signals in finite time. Meanwhile, considering the large chattering phenomenon caused by high switching gains, an improved sliding mode control method based on nonlinear disturbance observer is proposed to reduce chattering. Through disturbance estimation for feedforward compensation, the improved sliding mode controller may take a smaller value for the switching gain without sacrificing disturbance rejection performance. Simulation results are provided to confirm the effectiveness of the proposed approach.

Corrections to “Extended State Observer-Based Integral Sliding Mode Control for an Underwater Robot With Unknown Disturbances and Uncertain Nonlinearities”

Abstract: This paper develops a novel integral sliding mode controller (ISMC) for a general type of underwater robots based on multiple-input and multiple-output extended-state-observer (MIMO-ESO). The difficulties associated with the unmeasured velocities, unknown disturbances, and uncertain hydrodynamics of the robot have been successfully solved in the control design. An adaptive MIMO-ESO is designed not only to estimate the unmeasurable linear and angular velocities, but also to estimate the unknown external disturbances. An ISMC is then designed using Lyapunov synthesis, and an adaptive gain update algorithm is introduced to estimate the upper bound of the uncertainties. Rigorous theoretical analysis is performed to show that the proposed control method is able to achieve asymptotical tracking performance for the underwater robot. Experimental studies are also carried out to validate the effectiveness of the proposed control, and to show that the proposed approach performs better than a conventional potential difference (PD) control approach.