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One of the standard problems in controller design of linear systems is the so-called pole placement problem. Although there are meanwhile a couple of algorithms for this problem on the market, the most common approach (at least for single-input systems) is the one suggested by Jiirgen Acl< ermann ‘-As it was recently shown by Alan Laub er a/fa 2, this algorithm is numerically harmful. For systems of larger than l0th order, double precision is required on a 32-bit machine (eg VAX); for systems larger than about lS “‘order, the algorithm fails altogether. Newer algorithms making use of a numerically more stable transformation (eg Hessenberg form) are behaving better, but were shown to fail as well for systems of larger than approximately 20"‘to 25* h order. The authors therefore suggested (without proof) that the pole placement problem is intrinsically ill-posed. in this paper, we present an algorithm which shows …