A new stability test for two-dimensional discrete systems using bilinear continuous fractions

An algorithm for testing the stability of single-input single-output (SISO) two-dimensional discrete-time systems is presented, using a method in the z-domain exclusively. It is based on expanding the bilinear discrete reactance function into z-domain continuous fractions in a mixed fashion. It is faster than B.M. Karan and M.C. Srivastava's algorithm (1986) and compares favorably with the commonly used tabular form of testing stability of 2-D systems. Two examples are given to illustrate the method and its practical implementation.<>