Simulink Model for y = -lOy + f(t)
Construct a SimuIink model to solve
y = -10y + ƒ(t) y(O) = 1
where ƒ(t) = 2 sin 4t, for 0 ≤ t ≥ 3.
To construct the simulation, do the following steps,
1. You can use the model shown in Figure 9.2-2 by rearranging the blocks as shown in Figure 9″.2-4.You will need to add a Sum block.
2. Select the Sum block from the Math Operations library and place it as shown in the simulation diagram. Its default setting adds two input signals. To change this, double-click on the block, and in the List of Signs window, type I+ – The signs are ordered counterclockwise from the top. The symbol I is a spacer indicating here
that the top port is to be empty.
3. To reverse the direction of the Gain block, right-click on the block, select Format from the pop-up menu, and select Flip bIock.
4. When you connect the negative input port of the Sum block to the output port of the Gain block, Simulink will attempt to draw the shortest line. To obtain the more standard appearance shown in Figure 9.2-4, first extend the line vertically down from the Sum input port. Release the mouse button and then click on the end of the line and attach it to the Gain block. The result will be a line with a right angle. Do the same to connect the input of the Gain to the arrow connecting the Integrator and the Scope. A small dot appears to indicate that the lines have been successfully connected. This point is called a take off point because it takes the value ‘of the variable represented by the arrow (here, the variable y) and makes that value available to another block.
5. Select Configuration Parameters from the Simulation menu, and set the Stop time to 3. Then click OK •
6. Run the simulation as before and observe the results in the Scope.