lnts.gms : Particle steering COPS 2.0 #9
Minimize the time take for a particle, acted upon by a thrust of
constant magnitude, to achieve a given altitude and terminal
velocity.
This model is from the COPS benchmarking suite.
See http://www-unix.mcs.anl.gov/~more/cops/.
The number of discretization points can be specified using the command
line parameter --nh. COPS performance tests have been reported for nh
= 50, 100, 200, 400
References:
- Dolan, E D, and More, J J, Benchmarking Optimization Software with COPS. Tech. rep., Mathematics and Computer Science Division, 2000.
- Betts, J, Eldersveld, S, and Huffman, W, Sparse Nonlinear Programming Test Problems. Tech. rep., Boeing Computer Services, 1993.
- Bryson, A E, and Ho, Y, Applied Optimal Control: Optimization, Estimation, and Control. John Wiley and Sons, 1975.
Large Model of Type: NLP
$Title Particle steering COPS 2.0 #9 (LNTS,SEQ=237)
$ontext
Minimize the time take for a particle, acted upon by a thrust of
constant magnitude, to achieve a given altitude and terminal
velocity.
This model is from the COPS benchmarking suite.
See http://www-unix.mcs.anl.gov/~more/cops/.
The number of discretization points can be specified using the command
line parameter --nh. COPS performance tests have been reported for nh
= 50, 100, 200, 400
Dolan, E D, and More, J J, Benchmarking Optimization
Software with COPS. Tech. rep., Mathematics and Computer
Science Division, 2000.
Betts, J, Eldersveld, S, and Huffman, W, Sparse
Nonlinear Programming Test Problems. Tech. rep.,
Boeing Computer Services, 1993.
Bryson, A, and Ho, Y, Applied Optimal Control:
Optimization, Estimation, and Control. John Wiley and Sons,
1975.
$offtext
$if set n $set nh %n%
$if not set nh $set nh 50
sets h intervals / h0 * h%nh% /
c coordinates / y1 first position coordinate
y2 second position coordinate
y3 first velocity coordinate
y4 second velocity coordinate /
scalars
pi a famous constant
nh number of intervals / %nh% /
a magnitude of force / 100.0 / ;
variables
u(h) control
y(c,h) coordinates
tf final time ;
positive variables
step step size
equations tf_eqn, pos_eqn(c,h), velo1_eqn(h), velo2_eqn(h);
tf_eqn.. tf =e= step*nh;
pos_eqn(c+2,h+1).. y(c,h+1) =e= y(c,h) + 0.5*step*(y(c+2,h) + y(c+2,h+1));
velo1_eqn(h+1).. y('y3',h+1) =e=
y('y3',h) + 0.5*step*(a*cos(u(h)) + a*cos(u(h+1)));
velo2_eqn(h+1).. y('y4',h+1) =e=
y('y4',h) + 0.5*step*(a*sin(u(h)) + a*sin(u(h+1)));
pi = 2*arctan(inf);
u.lo(h) = -pi/2;
u.up(h) = pi/2;
y.fx(c,'h0') = 0;
y.fx('y2','h%nh%') = 5;
y.fx('y3','h%nh%') = 45;
y.fx('y4','h%nh%') = 0;
step.l = 1.0/nh;
y.l('y2',h) = 5*(ord(h)-1)/nh;
y.l('y3',h) = 45*(ord(h)-1)/nh;
model lnts /all/;
$if set workspace lnts.workspace = %workspace%;
solve lnts using nlp minimizing tf;