Showing papers by "Lars Hedrich published in 2002"
10 Jun 2002
TL;DR: This contribution presents the first method for model checking on nonlinear analog systems, based on digital CTL model checking algorithms and results in hybrid model checking, and an extension to the CTL language is needed.
Abstract: In this contribution we present the first method for model checking on nonlinear analog systems. Based on digital CTL model checking algorithms and results in hybrid model checking, we have developed a concept to adapt these ideas to analog systems. Using an automatic state space subdivision method the continuous state space is transferred into a discrete model. In doing this, the most challenging task is to retain the essential nonlinear behavior of the analog system. To describe analog specification properties, an extension to the CTL language is needed. Two small examples show the properties and advantages of this new method and the capability of the implemented prototype tool.
82 citations
Journal Article•
TL;DR: A new method for developing discrete models for nonlinear analog systems using an adaptive state space intersection method so the main nonlinear properties of the analog system can be retained and digital model checking ideas can be applied to analog systems.
Abstract: In this contribution we present a new method for developing discrete models for nonlinear analog systems. Using an adaptive state space intersection method the main nonlinear properties of the analog system can be retained. Consequently, digital model checking ideas can be applied to analog systems. To describe analog specification properties an extension to the standard model checking language CTL and the appropriate, algorithmic modifications are needed. Two nonlinear examples are given to show the feasibility and the advantages of this method.
36 citations
27 Jul 2002
TL;DR: In this paper, the authors present a new method for developing discrete models for nonlinear analog systems using an adaptive state space intersection method, where the main nonlinear properties of the analog system can be retained.
Abstract: In this contribution we present a new method for developing discrete models for nonlinear analog systems. Using an adaptive state space intersection method the main nonlinear properties of the analog system can be retained. Consequently, digital model checking ideas can be applied to analog systems. To describe analog specification properties an extension to the standard model checking language CTL and the appropriate, algorithmic modifications are needed. Two nonlinear examples are given to show the feasibility and the advantages of this method.
34 citations
10 Nov 2002
TL;DR: A novel affine-arithmetic Newton operator is defined that gives a significant improvement in computational efficiency over an implementation using interval arithmetic and calculates guaranteed bounds on the worst-case behavior and finds the global optimum of the sizing problem by means of branch-and-bound optimization.
Abstract: We present a novel approach to optimization-based variation-tolerant analog circuit sizing. Using formal methods based on affine arithmetic, we calculate guaranteed bounds on the worst-case behavior and deterministically find the global optimum of the sizing problem by means of branch-and-bound optimization. To solve the nonlinear circuit equations with parameter variations, we define a novel affine-arithmetic Newton operator that gives a significant improvement in computational efficiency over an implementation using interval arithmetic. The calculation of guaranteed worst-case bounds and the global optimization are demonstrated by a prototype implementation.
33 citations
04 Mar 2002
TL;DR: An approach for parameter controlled symbolic analysis of nonlinear analog circuits based on a state-of-the-art algorithm that enables the removal of specific circuit parameters from a symbolic circuit description, given as a set of non linear differential algebraic equations (DAEs).
Abstract: In this paper we introduce an approach for parameter controlled symbolic analysis of nonlinear analog circuits. Based on a state-of-the-art algorithm, it enables the removal of specific circuit parameters from a symbolic circuit description, given as a set of nonlinear differential algebraic equations (DAEs). During the removal, singularities are considered, which includes structural changes of the set of DAEs. The feasibility of our approach is shown by several circuit examples.
1 citations