This paper presents a tracking control problem of flexible air-breathing hypersonic vehicle with input constraint and aerodynamic uncertainty. Without ignoring aero-propulsive and elevator-to-lift couplings, a control-oriented model including aerodynamic uncertainty is firstly established. Then a robust adaptive backstepping control scheme is designed, in which the control-oriented model does not need to be transformed into linear parameterization formulation. Upper bounds of the uncertain terms do not need to be known in advance, which are estimated online by designing robust adaptive laws. To further consider input constraint, a constrained robust adaptive backstepping controller is proposed to simultaneously handle input constraint and aerodynamic uncertainty. Finally, the compared simulation results show the effectiveness of the designed control strategy.

This article presents an adaptive filter backstepping control strategy for reusable launch vehicles attitude tracking during reentry phase in the presence of input constraints, model uncertainties and external disturbances. The control-oriented model with uncertainties is constructed, where the uncertainties do not satisfy the linear parameterization assumption. To cope with input constraints, an auxiliary system is introduced, and the states of which are applied to the procedure of control design and stability analysis. Second-order filters are employed to overcome the ‘explosion of terms’ problem inherent in traditional backstepping control. Moreover, the stability of the closed-loop system is proven via Lyapunov technique, and the tracking error can be forced into an arbitrarily small neighborhood around zero (i.e. semi-globally uniformly ultimate bounded tracking). Finally, the 6-degree-of-freedom nonlinear reusable launch vehicle simulation results are presented to verify the effectiveness of the control strategy.

To provide faster, more repeatable, and stronger microelectronics bonding technology, this article presents the design and implementation of a robust and precision controller for a highspeed linear voice-coil motor, direct-drive, XY positioning table. Moreover, the dynamic design methodology of the control system for the positioning table is proposed based on electromechanical co-simulation. Using the finite-element method and dynamic analysis, the rigid-flexible coupled mechanical model of the XY table is established. With the aid of the system identification approach, the open-loop model of the control system for the X -axis table is obtained. On this basis, the proportion integration differentiation controller with incomplete derivation and the sliding mode controller (SMC) with the exponential reaching law are designed to control the X -axis table. The performances of the controllers are investigated using electromechanical cosimulations and experimental tests, and the results show that the motion overshoot and settling time are reduced using the SMC with an exponential reaching law. The SMC with the exponential reaching law also shows strong robustness against external disturbances. The experiment and co-simulation results are in good agreement, which confirms the validity and feasibility of the dynamic design methodology for a high-speed and high-accuracy positioning table based on electromechanical co-simulation.

This article presents a high-acceleration precision positioning system to improve the efficiency and precision of micro-electro-mechanical system (MEMS) packaging. The positioning system is direct driven by linear voice coil actuators (LVCAs), and the mass and inertia of the motion system are significantly reduced by using a novel flexible decoupling mechanism based on flexure hinges. The decoupling principle of the mechanism is introduced, and the flexure hinges are designed by using an analytical method. Through dynamic analysis, the stiffness and preload of the spring are determined. With the aid of finite-element method and dynamic analysis, the influences of flexure hinges on the characteristics of the positioning system are investigated. Based on the dynamic characteristics of LVCA and the developed mechanism structure, the electromechanical coupled models are established. Minimum deadbeat response control strategy with a pre-filter is implemented to control the positioning system, and the parameters of the controller are optimized. Experimental tests are carried out to examine the characteristics of the positioning system. The results show that the positioning system provides good performances and satisfies the requirements of MEMS packaging operations.

This article presents a high-acceleration rotary bond head to improve the efficiency and precision of thermosonic bonding. The bond head is direct driven by a rotary voice coil actuator, and needle roller bearings are adopted as the rotary connection parts. Using the finite-element analysis and experiment tests, the dynamic characteristics of the bond head were investigated. The results indicate that the vibrations of the bond head have negative influences on the bonding process and the ultrasonic transducer system. They can reduce the efficiency of the ultrasonic energy transmission and even result in the bonder working abnormally. To avoid these vibration modes, high-frequency harmonic components of the driving signals were eliminated by adding a notch filter to the control system. Considering the remnant vibrations during high-frequency starts and stops, friction compensation and proportion integration differentiation (PID) feedback control with anti-windup correction were adopted. The controller was designed and co-simulated by using MATLAB and MSC.ADAMS software. The co-simulation and experiment results show that the bond head provides for good performances.