//-------------------------------------------------------------------------
//
// Nonlinear damper curve.
//
// Reference: Gordon, T. J. and Best, M. C. (1994), "Dynamic optimization
//            of nonlinear semi-active suspension controllers",
//            Proc. International Conference on Control (Control'94), IEE,
//            vol. 1, pp. 332-337, Conventry, UK, March.
//
// Author: Jose Paulo V. S. da Cunha
//
// Rio de Janeiro, April 16, 2002.
//
//-------------------------------------------------------------------------

// Velocity range (m/s):

v=-2:0.01:2;

// Plot velocity  x damper force (v x Fd):

xbasc();
xset("default");
xset("font size",4);
xset("line style",1);
plot2d(v,(7.5*v+40*atan(v*10)/%pi)*0.025,rect=[-2,-1,2,1]);

// Plot upper and lower bounds:

xset("line style",10);
plot2d(v,(20*ones(length(v))+7.5*abs(v))*0.025);
plot2d(v,(-20*ones(length(v))-7.5*abs(v))*0.025);

// Plot grids and comments:

xset("line style",2);
xgrid(1);
xtitle('','v (m/s)','Fd (N)');