If you just want to display the transfer function in time-constant form, you can do the following:
s = tf('s');
k = 45; % anyhting
G = k/(100*s^2+20*s+1) % expanded polynomial form
[z,p,k] = zpkdata(G)
G1 = zpk(z,p,k,'DisplayFormat','timeconstant')
If you want access to the time constants, use damp.m
damp(G)
[w, zeta, p] = damp(G)
tau = 1./w
I',m assuming you have a stable TF. Check with isstable.
