Beyond HyTech: Hybrid Systems Analysis Using Interval Numerical Methods

  • Thomas A. Henzinger
  • Benjamin Horowitz
  • Rupak Majumdar
  • Howard Wong-Toi
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1790)


Since hybrid embedded systems are pervasive and often safety-critical, guarantees about their correct performance are desirable. The hybrid systems model checker HyTech provides such guarantees and has successfully verified some systems. However, HyTech severely restricts the continuous dynamics of the system being analyzed and, therefore, often forces the use of prohibitively expensive discrete and polyhedral abstractions. We have designed a new algorithm, which is capable of directly verifying hybrid systems with general continuous dynamics, such as linear and nonlinear differential equations. The new algorithm conservatively overapproximates the reachable states of a hybrid automaton by using interval numerical methods. Interval numerical methods return sets of points that enclose the true result of numerical computation and, thus, avoid distortions due to the accumulation of round-off errors. We have implemented the new algorithm in a successor tool to HyTech called HyperTech. We consider three examples: a thermostat with delay, a two-tank water system, and an air-traffic collision avoidance protocol. HyperTech enables the direct, fully automatic analysis of these systems, which is also more accurate than the use of polyhedral abstractions.


Hybrid System Reachable State Interval Method Rate Translation Hybrid Automaton 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • Thomas A. Henzinger
    • 1
  • Benjamin Horowitz
    • 1
  • Rupak Majumdar
    • 1
  • Howard Wong-Toi
    • 2
  1. 1.Department of Electrical Engineering and Computer SciencesUniversity of California at BerkeleyBerkeley
  2. 2.Cadence Berkeley LaboratoriesBerkeley

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