Based on Lyapunov theorem, two different types of control schemes for solving robust tracking problems are presented in this thesis. The first one is model reference adaptive sliding mode control, which is designed for a class of SISO LTI systems with relative degree one possessing additive and multiplicative unstructured uncertainties in the input and output channels. By introducing a perturbation estimation process embedded in the proposed control scheme, the chattering phenomenon can be reduced effectively since only the perturbation estimation error needs to be overcomed. The second one is optimal model reference adaptive control, which is designed for a class of multi-input systems with input non-linearity. These systems are subject to model uncertainties and time-varying delay.

As the electronic products are gotten smaller and the quantity of output is to be requested, the trend of the needs for speed and accuracy is more precise. Therefore, upgrading the speed and the accuracy of contour error on tracking control has become an important point. This research is focus on the improvement of tracking error and contour error. In tracking error, we propose that the compensation of friction disturbance is by building friction model. And then adaptive robust controller is used to eliminate other disturbance. Finally, velocity feedforward controller is used to improve system dynamic response and to remove the effect of time delay. The combination of such controllers can improve tracking error directly and contour error indirectly. In contour error, we use cross-coupled controller to coordinate the motors and to reform contour error. On the association of such controllers, we propose the design method of cross-coupled controller, to replace the traditional way of try-and-error, and improving contour error again. Finally, the above improving strategies are verified by the simulation and experimental results.

Based on the Lyapunov stability theorem, a model reference adaptive variable structure control (MRAVSC) scheme with perturbation estimation is presented in this thesis for solving robust tracking problems. The plant considered belongs to a class of MIMO linear time invariant systems with arbitrary relative degree possessing additive and multiplicative unstructured uncertainties in the input and output channels. By introducing a perturbation estimation process embedded in the proposed control scheme, both the perturbations and differentials of tracking errors can be estimated. In addition, the proposed control scheme also contains an adaptive mechanism in order to automatically adapt the unknown upper bound of perturbation estimation error, and guarantee the property of uniformly ultimate boundedness for the closed-loop controlled system. Finally, two numerical examples are presented to demonstrate the feasibility of the proposed control scheme.

In this thesis the synchronization of two different chaotic systems with matched and mismatched perturbations are developed by utilizing adaptive backstepping control technique. The adaptive mechanisms embeded in the proposed control scheme is used to adapt the unknown upper bounds of the perturbations. The resultant robust backstepping tracking controller with adaptive mechanisms can indeed drive the trajectories of the slave system to track those of the master system. Two numerical examples and simulations are given to illustrate the correctness of theoretical analyses.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents the architecture of a new dynamic multi-protocol network interface implemented on a TT&C satellite baseband processor. Today Ethernet is the main connection of the equipment in a satellite system. Various protocols are necessary to optimize support of data exchange and are implemented using several supports such as Serial lines, Ethernet or Internet. The capability to dynamically switch from one service to another, using the most adapted interface, is the key factor for a multi-mission, multi-satellite system.

As the electronic products are getting more and more small, the trend of the needs for speed and accuracy is more precise. Therefore, upgrading the speed and the accuracy of contour error on tracking control has become an important point. This research is focus on the improving of contour error and terminus error. In the contour error, we design the acceleration /deceleration profile based on digital FIR filter. And then remodel the compensatory method of cross-coupled controller, making the design of controller parameter easier, and getting better efficiency. And further, we get the time-variable gain by curve of contour error, making the accuracy better. In terminus error, according to two-step control, we switch the controller in deceleration region, not only directly improving the terminus error, but also improving the contour error. Finally, the above improved strategies are verified by the simulation and experimental results.

Three robust tracking control design strategies are proposed in this dissertation for different classes of nonlinear MIMO dynamic systems with mismatched perturbations. The first controller design method is proposed for a class of nonlinear MIMO dynamic systems in canonical form. The second design procedure of controller is for the nonlinear MIMO dynamic systems without canonical form. A decentralized controller is presented in the last for perturbed large-scale systems with time-varying delay interconnections, where the knowledge of the exact function of time-delay is not required. These robust tracking controllers with a perturbation estimating scheme and an adaptive control mechanism embedded are designed by means of the variable structure control technique and Lyapunov stability theorem. The adaptive control mechanism is used to adapt the unknown upper-bound of perturbation estimation error, so that the knowledge of upper-bounds of perturbation as well as perturbation estimation error is not required. The chattering phenomenon is effectively alleviated, for the gain of the proposed controllers, which needs only to overcome the perturbation estimation error, is in general smaller than those of the traditional sliding mode controllers. Furthermore, the stability of the overall controlled systems is proved, and the desired tracking accuracy can be achieved by adjusting the design parameters of the proposed controller schemes. A numerical example for each controller's design is provided for demonstrating the feasibility of the proposed control schemes.

A high-frequency electronic ballast with auto-tracking control was proposed to operate the metal halide lamps at a specific frequency free from acoustic resonance. In case the acoustic resonance should happen, the operating frequency is changed step by step with the auto-tracking control, until the lamp is operated at a frequency with stable operation. The electrical characteristics of the lamps are first investigated. Based on the investigated results, a detection circuit is designed to identify the occurrence of acoustic resonance. With the auto-tracking control, the Class-D half-bridge series-resonant inverter can be adopted for the high-frequency electronic ballast to achieve high efficiency and high power density. The control strategy of auto-tracking is practically realized by a single-chip microprocessor. The proposed approach is implemented on a 70 W test lamp with an operating frequency range from 20 kHz to 30 kHz. To regulate the lamp power at its rated value, a buck-boost converter is used as a pre-regulator, which serves also as a power-factor-corrector to achieve a high power factor at the input line.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 108-112).

The automation of hydraulic mobile machinery, such as excavators, requires high performance control solutions. In hydraulics, this means fast and accurate force, velocity and position control of hydraulic cylinder. Especially the force control is known to be difficult with traditional servo valves. Fast digital hydraulic valves together with modern control solutions can overcome this problem. This paper uses a new force control solution, which is based on the fast digital hydraulic valves and model based control principle. The control solution is applied in a heavy axis mimicking dynamics of mobile machine booms. Experimental results show good force, velocity and position tracking performance with varying load masses. The slow velocity performance is also much improved when compared to the earlier results.