$*************************************************************
$ Minimum Time to Cover a Fixed Distance
$ L. T. Biegler and I. B. Tjoa
$
$ CACHE Process Design Case Studies
$ M. Morari and I.E. Grossmann
$
$ Optimal Solution:  34.641
$*************************************************************

OPTION {{
  FTOL = "1e-4";
  OTOL = "1e-4";
}}

DECLARATION {{
  XVAR {k1,k2,k3,tau};
  LBDS tau = {0.1};
  XSTP {1,1,1,20};

  ZVAR {x1,x2,u};
  ISPE {x1,x2};
  ZINC {0,0,0};
  TIME {0,1.0};
}}

MODEL {{
  MIN:  tau;
  dae1: x1' =e= tau*x2;
  dae2: x2' =e= tau*u;
  dae3: u =e= k1 + k2*t + k3*t^2;
  con[0]: u =l= 1;
  con[0]: u =g= -2;
  con[1]: u =l= 1;
  con[1]: u =g= -2;
  con[1]: x1 =e= 300;
  con[1]: x2 =e= 0;
}}