setting initial conditions for laplace transformation

How do I set all the initial consitions for the following code to =0

clc

clear

%-------------------------------------------------SYSTEM_PARAMETERS----------------------------------------------------------------------------------------------------------------------------------------------------------

Ic=1356; %kg-m^2

Mb=730; %kg

Mf=59; %kg

Mr=45; %kg

Kf=23000; %N/m

Ksf=18750; %N/m

Kr=16182; %N/m

Ksr=12574; %N/m

Bsf=100; %N*s/m

Bsr=100; %N*s/m

L1=1.45; %m

L2=1.39; %m

L3=0.67; %m

syms Xf(t) Xr(t) Xb(t) theta(t)

Xf_1=diff(Xf,t);

Xf_2=diff(Xf,t,2);

Xr_1=diff(Xr,t);

Xr_2=diff(Xr,t,2);

Xb_1=diff(Xb,t);

Xb_2=diff(Xb,t,2);

theta_1=diff(theta,t);

theta_2=diff(theta,t,2);

eqn1=Mf*Xf_2+Bsf*(Xf_1-(Xb_1-(L1*theta_1)))+Ksf*(Xf-(Xb-(L1*theta)))-Kf*Xf

L_eqn1=laplace(eqn1)

eqn2=Mr*Xr_2+Bsr*(Xr_1-(Xb_1-(L2*theta_1)))+Ksr*(Xr-(Xb-(L2*theta)))-Kr*Xr

L_eqn2=laplace(eqn2)

eqn3=Mb*Xb_2-Bsf*(Xf_1-(Xb_1-(L1*theta_1)))-Ksf*(Xf-(Xb-(L1*theta)))-Bsr*(Xr_1-(Xb_1-(L2*theta_1)))-Ksr*(Xr-(Xb-(L2*theta)))==10*exp(-5*t)

L_eqn3=laplace(eqn3)

eqn4=Ic*theta_2+Bsf*(Xf_1-(Xb_1-(L1*theta_1)))*L1+Ksf*(Xf-(Xb-(L1*theta)))*L1-Bsr*(Xr_1-(Xb_1-(L2*theta_1)))*L2-Ksr*(Xr-(Xb-(L2*theta)))*L2==(10*exp(-5*t))*L3

L_eqn4=laplace(eqn4)

Answer 1

[Torsten]

L_eqn1 = subs(L_eqn1,[Xb(0) Xr(0) Xf(0) theta(0) Xb_1(0) Xr_1(0) Xf_1(0) theta_1(0)],[0 0 0 0 0 0 0 0])

Same for the other equations.