Control vehicles velocity according to speed signs

I want to make a controller that takes value from traffic speed sign and control vehicles velocity according to speed signs. Requirements: vehicle run on pre defined maneuver speed until it detects speed sign on road. As soon as it detects speed sign, vehicle velocity should change to that value and continue until next sign detected.

How can I model? Please help me to get some idea. i am stuck at a point where traffic speed signs are out of the range of sensor. At that time vehicle velocity is going down instead of remain constant.

Answer 1

[Sam Chak]

@Purvil Patel, Here is th basic idea.

Even though some speed limit signs maybe out of the sensor's range, the controller should be able to hold on the last detected speed limit.

Gp = tf(1, [1 1]);
t  = linspace(0, 40, 4001);
u1 = 5*heaviside(t);
u2 = 2*heaviside(t - 10);
u3 = 1*heaviside(t - 20);
u4 = 2*heaviside(t - 30);
u  = u1 - u2 + u3 - u4;
lsim(Gp, u, t)
grid on, ylim([0 6])