本文以離散控制作為方向，以H控制理論作為基底，去推導離散H/LTR設計方法。H控制器可以容忍各式各樣的外擾，但是在H控制理論中並未提及對系統性能的設計，也就是H控制理論能夠確保系統在外擾下的穩定性且擁有排除各種系統不確定性干擾之良好能力，但卻無法保證系統擁有預設之所需的性能。
為了改善這一個缺點，採用LQG/LTR設計理念，將其觀測器與控制器增益矩陣，改以H控制理論來設計。為H控制理論發展H/LTR設計程序，藉由透過事先設定的目標回授迴路(Target Feedback Loop ; TFL)，使得H控制器符合所需要的性能。
接著推導具不確定性(Uncertainty)的非線性物理系統，使之可延續H∞/LTR的設計步驟。最後，本文針對一直流馬達系統作為電腦模擬控制對象，來驗證所設計之H/LTR控制器可行性。

Although the H-optimal control law is relatively robust to various system uncertainties or disturbances, the prescribed performance-matching problem remains to be solved. A discrete-time H∞/LTR technique is therefore developed in this thesis for the discrete-time systems to solve the performance-matching problem by using the loop transfer recovery (LTR) technique.

To match the prescribed specifications for the H2-problem in dealing with white Gaussian noises (or disturbances), the LQG/LTR technique is well developed and is available in many literatures. A similar design methodology for H∞-control problems is developed in this thesis to minimize the H∞-norm of the closed-loop transfer function matrix between the exogenous inputs and the controlled outputs so that the proposed H∞/LTR control law will be robust to various uncertainties and disturbances while the desired performance can also be matched.

A step by step design procedure is also formulated in this paper to facilitate the feasibility of the proposed H∞/LTR methodology for the discrete-time system. Finally, a DC-motor is studied to illustrate the proposed design concepts.

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