block diagram cooperative adaptive cruise control

hi everyone, I'm trying to realize the following block diagram on simulink

where:

H=h*s+1;

G=1/(s^2*(tau*s+1));

K=kp+kd*s+kdd*s^2;

I realized this block diagram on simulink

is it correct how I represented the improper function?

when I run the simulation, I receive this message:

A valid state attribute should be a non-missing string array, a character vector, a cell array or a valid MATLAB structure.

thanks for your help!!

[Sam Chak]

Hi @massimiliano frasca

I'm not sure, but can you check if the following signals are correct?

Also, your block diagram implies that , when it should be .

Another one is , when it should be .

By the way, what are you trying to accomplish with the proposed block diagram?

Can it really estimate ?

Why estimate when the output can be measured?

[massimiliano frasca]

hi, thanks for your answer. I'm trying to study cooperative adaptive cruise control (pdf attachment).

This block diagram refers to the i-vehicle of a platoon.

The signals are correct exept ri=H*si. It should be qi=H*si

[massimiliano frasca]

without ui-1 we have the classic adaptive cruise control

Answer 1

[Sam Chak]

Hi @massimiliano frasca

Actually, I have trouble reading that conference article. If authors set to prevent jerk, why did they propose in the first place? Anyhow, here is my attempt, which may not reflect the authors did (cause I don't how they did it). The and may actually refer to the vehicles behind the CCAC-equiped vehicle. I avoid using the derivative block, especially the Double-D blocks.

[massimiliano frasca]

thanks for your answer!

However, I didn't understand how you realized K and invH (using integrators?). I have some difficulties in this sense, simulink doensn't allow to use improper transfer fuction

[Sam Chak]

@massimiliano frasca

Ya, most papers don't state the obvious for some unknown reasons, either they don't want to let young people or they simply follow others in the literature. In Simulink or in Transfer Function mode (as per Fig. 3), one definitely cannot enter Eq.(8) just like that. So, we have to integrate Eq.8 to obtain

This approach can take care of simultaneously.

How do get the errors and without using the Derivative Block?

This sentence states that can be obtained from ,. If and we assume that or a slow-varying reference, then and thus, . That's why I tapped this after Integrator2 block and multiplied it with the Kd block and changed the sign to minus '–' at the summation point. So, I can avoid using the Derivative block. Do it similarly for , this can be tapped from the acceleration output .

Also, I didn't use Eq.(14). Instead, from Eq.(16), you see the idea already where , output of Integrator2 block. One thing I don't like writing style of the paper because sometimes, they are in time-domain, other times they are in s-domain.

I hope the Simulink model gives you new insights on the modeling approach and skills.

If you find my explanations and Simulink model are helpful, please consider accepting ✔ and voting 👍 the Answer. Thanks.

[massimiliano frasca]

thanks <3