Project 2 - Speed Control of a Direct Current (DC) motor

Script files

% Design Parameters to model a DC motor

Jm = input('Enter moment of inertia in Kg-m^2 J :');

Bm = input('Enter motor viscous friction constant in N-m-s B :');

Km = input('Enter Back EMF constant in v/rad/s Km :');

Kt = input('Enter motor torque constant in N-m/amp Kt :');

Ra = input('Enter Armature resistance in ohms Ra :');

La = input('Enter Armature inductance in Henries La :');

wc = input('Enter the Reference speed of motor wc :');

%PD control Design

% Plant matrices

A = [-Bm/Jm Kt/Jm; -Km/La -Ra/La];

B = [0; 1/La];

C = [1 0];

D = [0];

%Pole Placement Design

fn=1;

wn=2*pi*fn;

zeta = 0.5;

p1 = -zeta*wn+wn*sqrt(zeta^2-1);

p2 = -zeta*wn-wn*sqrt(zeta^2-1);

P = [p1;p2];

K = place(A,B,P);

Kp = K(1)

Kd = K(2)

Ki = input('Enter integral gain Ki :');

figure(1)

subplot(321);plot(out.time,out.Vs);grid;title('Supply Voltage (V)');

subplot(322);plot(out.time,out.Vb);grid;title('Back EMF (V)');

subplot(323);plot(out.time,out.Ia);grid;title('Armature Current (A)');

subplot(324);plot(out.time,out.t);grid;title('Torque (N-m)');

subplot(325);plot(out.time,out.w,'m--');hold;grid;title('Rotor Speed (rad/s)');

subplot(325);plot(out.time,out.wc,'b-');