包含了控制理论的各种仿真程序

				%  Figure 6.70      Feedback Control of Dynamic Systems, 4e
				%                   Franklin, Powell, Emami
				% 
				
				clear all
				close all;
				
				num=0.9*0.05*conv([1 2],[10 1]);
				num=conv(num,[1 0.005]);
				den=[1 2 0 0 0];
				den=den+[0 0 2*0.9*0.05*conv([10 1],[1 0.005])];
				t=0:.5:40;
				y=step(num,den,t);
				subplot(2,1,1)
				plot(t,y);
				grid;
				xlabel('Time (sec)');
				ylabel('\theta');
				title('Fig. 6.70 (a) Step Response with PID compensator');
				subplot(2,1,2)
				%now disturbance response
				numd=0.9*[1 2 0];
				t=0:5:1000;
				yd=step(numd,den,t);
				plot(t,0.1*yd);
				grid;
				xlabel('Time (sec)');
				ylabel('\theta');
				title('Fig. 6.70 (b) Step Disturbance Response with PID compensator');