Application of fuzzy logic structures in CAD of digital electronics substantially improves quality of design solutions by providing designers with flexibility in formulating goals and selecting tradeoffs. In addition, the following aspects of a design process are positively impacted by application of fuzzy logic: utilization of domain knowledge, interpretation of uncertainties in design data, and adaptation of design algorithms. We successfully applied fuzzy logic structures in conjunction with constructive and iterative algorithms for selecting of design solutions for different stages of the design process. We also introduced fuzzy logic software development tool to be used in CAD applications.

A planar three degree-of-freedom parallel manipulator has been extensively studied as the fundamental example of parallel manipulators. It has been proven from the authors' previous work (1996) that when three identical joint compliances are attached to the three base joints of the mechanism in its symmetric configurations, this mechanism possesses a completely decoupled compliance characteristic at the object space, which is the important operational requirement for remote centre of compliance device. In this paper, we concern about the adjustability of the output compliance matrix of this mechanism by employing redundancy on either joint compliances or on actuators. Two approaches are suggested to achieve this purpose: 1) the stiffness modulation is achieved through purely, redundant passive springs or decoupled feedback stiffness gains; and 2) the stiffness modulation is achieved through antagonistic actuation of the system actuators. General stiffness models are derived for both cases. Based on these stiffness models, stiffness modulation algorithms are formulated.

A three degree-of-freedom planar parallel manipulator has been extensively studied as the fundamental example of parallel manipulators. In this work, we explicitly show that this mechanism possesses a completely decoupled compliance characteristic at the object space, which is the important operational requirement for RCC devices. As a first condition to have a RCC point, this mechanism should maintain symmetric configurations. As the second condition, the same magnitude of joint compliance should be symmetrically placed at the same joint location of each chain. An alternative planar configuration with more adjustable feature of compliance is introduced. We also investigate the compliance characteristics of a spherical 3-degree-of-freedom mechanism which has a similar kinematic structure as the planar mechanism. It turns out that the spherical mechanism also has a RCC point at the intersection point of all of nine joint axes in its symmetric configuration. It is expected that these two parallel mechanisms not only can be used as excellent three degree-of-freedom RCC devices, but also can be integrated into the design of a new six degree-of-freedom RCC device.

In this work, a technology-mapping procedure for FPGAs was developed, which takes into consideration multiple objectives while focusing on delay optimization. A constructive heuristic was used to minimize circuit delay and maximize the utility of CLBs. The target architecture of this mapper is Xilinx 4000 series, and a set of MCNC benchmarks was used to test the performance.