I am creating a simulink model for a mobile robot. The idea is to this robot goes to diferent coordinates (X, Y). I already have my controller (PI controller) and the full system simulated (motor model, dynamic model and kinematic model) and everything is working good; However, the reference I am given is based on time, this means that e.i every 100 seconds the reference is going to be change no matter if the robot reach or not the goal (the current reference in X and Y).
What I want to do is, insted of giving a centain amount of time, when the robot reach the goal (reference in X and Y), the next reference is given automatically (the referece can have a tolerance of .05 for example, so the simuluted robot does not have to reach 100% the goal).
I was thinking for doing it with a stateflow block with a feedback of the error to say something like: if the error is less than 0.05 you can send the next reference, but I am not sure how to translate it to the simulation (what to put inside the stateflow).
Of course if someone has a better idea I would like to read it.
if someone has experience with this I really appreciate your help. I attache some photos with the blocks that maybe they can better clarify it.
Current simulation block
My idea
Related
Using system dynamics on anylogic how can you model a simulation that will give an infectious curve of this nature(Below picture) using SEIR.
enter image description here
I have tried to simulate, however my graph goes up and down. It does not oscillate as per the attached picture.
I need to simulate something similar to the graph for my assingment.
There should be three types of events in your model.
First, lets call it "initial spread", is triggered on the start of your simulation.
Second, lets call it "winter season", is triggered annualy in November\December.
Third, lets call it "mass vaccination" - you can decide when to trigger it and for what selection of your agents.
So first two are kind of global events, and the third event is specific to some sub-population (this can make the third wave kind of "toothy" if you trigger it in slightly different moments for different populations).
That is pretty it.
Curios to see how your model will predict the fourth wave - second winter season of your simulation. So keep us updated :)
There are a number of ways to model this. One of the simplest ways is to simply use a time aspect for one of your infection rate parameters so that the infection rate increases or decreases with time.
See the example below.
I took the SIR model from the Cloud https://cloud.anylogic.com/model/d465d1f5-f1fc-464f-857a-d5517edc2355?mode=SETTINGS
And simply added an event to change the Infectivity rate using an event.
Changing the chart to only show infected people the result now looked something like this.
(See the 3 waves that were created)
You will obviously use a parameters optimization experiment to get the parameter settings as close to reality as possible
I'm making a dynamical system model in Simulink. It is a drop test on 2 springs. I want that after first drop the object will stop, so that in the accelaration graph there will be only 1 maximum. Am asking for a detailed answer. Thanks in advance.
The system to model
Current acceleration Graph
Simulink model
I know the time of the first cycSimulink modelle, but I calculate it only in the end of the run. I understand that I can use Matlab function in Simulink, and maybe a Subsystem.
when_shock=(acc.Time(two_times(2))+acc.Time(two_times(1)))/2;
I need the accelatarion graph to have only one peak. Meaning only one drop accures, after which the object stops. The force where the arrow shoud be zero after force drop.
I am hoping somebody here will be able to help me out with my small issue with one of the Simulink/Matlab code. It is quite similar to the problem that I’ve discussed earlier, but a little bit more complicated and now it is more a Simulink issue, rather than a Matlab one.
So I have a turbine which speed is controlled by the gate’s opening, hence the control voltage. By controlling the gate opening I am accelerating the turbine and at some point in time, I need to introduce a saturation effect (since I am testing the code now, it will be done an external signal). This effect won’t change the control voltage, but it affects other components of the system, hence at the same control voltage, the turbine’s speed will go up. But at the same time, I need to keep the speed at the same value as it was before the saturation effect (let’s say it was 320 rpm). To do so I need to decrease the control voltage and should keep doing it until I reach the speed as it was before. There is no need to do it instantly (this approach will be later introduced in hardware), but it will be a nice thing to check the algorithm in these synthetic tests.
In terms of the model, I was planning to use a while loop with the speed requirement “if speed > 320” again, now just to simplify things. To decrease the control voltage I was planning to subtract from the original 50 (% opening) - 0.25 (u2) at first and after that increasing this value by 0.25 until I decrease the speed below 320. I can’t know the exact opening when this requirement will be satisfied, hence I need some kind of algorithm to “track” this voltage.
So it should be something like this:
u2 = 0;
While speed > 320
u2 = u2+0.25
End
u2 is initially zero since we have a predefined initial control voltage. And obviously, when we reach the motor’s speed below 320, I need to keep the latest value of the u2 (and control voltage).
Overall, it is a small code and should be done in Simulink (don’t want to introduce any other Fcn function into the model). I’ve never used while and if blocks in Simulink, but so far I came up with this system. It’s a simplified version of my model, but the control principle is the same.
We are getting the motor speed of 350, compared with 320 (the speed before “saturation), and if our speed after saturation is higher, we need to reduce the control voltage. To trigger the while loop block I’ve decided to use a simple switch. The while block meanwhile is:
Definitely not the best implementation but I was trying a lot of different combinations and without any real success. I am always getting the same error:
Was trying to use a step signal instead of the constant “7” – to model acceleration of the motor, and was getting the same error at the moment of acceleration above 320 threshold. So looks like the approach is almost right but mathematically it fails to find the most suitable solution. I’ve tried to implement a transport delay in the memory part of the while subsystem but was getting errors during compilation all the time.
Are there any obvious (and not so) mistakes? Or maybe from the beginning, I should have chosen another approach… I really hope that somebody will be able to help. Thank you in advance and have a great day.
I do not think that you have used While block correctly.
This is what I have done, I used a "Matlab function" block instead of "While" block as follows,
The function in Matlab function is
function u2=fcn(speed,u2d)
if speed>320
u2=u2d+0.25;
else
u2=u2d;
end
And the results I have got, Scope 1
Scope
Edit
As you prefer a function free model, the following may do the same.
I am trying to develop a MATLAB Simulink model that will help me study the load of my department.
The model works, however one of the blocks goes right over my head when it comes to understanding, as I used the internet to help me with it.
Here is the main block:
The Scope Displays the Voltage, Current & Power
The "dept01" block inputs the data from .csv file and contains only [Time,Power].
Here is what goes inside of the "Electrical Department" Block:
I have no problem understanding this part, I'm simply splitting the total power into three portions.
NOTE: I am also assuming that ultimately Q=0 so Total Power = Real Power
This is the Second Step of the "Electrical Department" block which I cannot understand in any way. Maybe my concepts are weak but this part makes no sense to me.
Can someone please explain it to me that how is the block calculating Voltage & Current using just the Power??? Also how does it imitate the function of a Load so that the Energy Meter sees it as a load?
Thanks!
Load can be emulated by connecting a current source in series with the voltage source as it is seen the diagram. In your case, the controlled current source has been used. It also looks like the dependent current source is derived from the voltage. I request you to give the details of relational operator used and the sigma block. Without which you can not derive the relation ship. If the current is dependent on the voltage like the case, voltage and current can be calculated simply from the power.
This question is related to an issue that I encountered when I was playing with some blocks. Here's the model that I have,
As you can see, there are two kinds of connections, the inputs of the first connection(from the top to bottom) is u[1],u[2],u[3], other blocks are quite self-explanatory (all default values, except that startTime = 5 for the step input block).
From my knowledge, the first kind of connection only outputs angular velocity but not angle and angle acceleration(they are both zero), which is a bit not realistic(I'll explain why I did this). The second connection outputs an angular velocity as well.
My problem was that, in the Second connection, the clutch seems working all right(after 5 seconds the clutch is engaged(relative angular velocity w_rel = 0))
However, the first connection behaves quite differently. We can see that they are all flange connections, and angular velocities are all calculated from flange_a/b.phi, so we should expect that there is no angular velocity difference in the clutch no matter what the input (realExperssion1) is. But the interesting thing is that when I simulate the model, the left flange of the clutch is not moving, the right flange is rotating instead. Here're two plots of my results.
Connection1
Connection2
Actually, I should expect to see the flange_a.phi and flange_b.phi are all zero, and then I accidentally removed the annotation __Dymola_InlineAfterIndexReduction = true in the move block, then the model behaves as what I expected. I wound be really appreciated if anyone could help me explain what I saw. Thanks A LOT!
The documentation for the Move model clearly says
The user has to guarantee that the input signals are consistent to
each other
In your case, they are not consistent. So I'm not too surprised you get a strange answer. It was not clear to me why you even attempted to go this route. You imply in the message you would explain why, but I certainly didn't understand your motivation. I suspect that the Move model exists to allow the user to provide their own explicit functions for position, velocity and acceleration that Dymola will use during index reduction instead of generating those functions from the underlying equations. Unless you can provide consistent functions, you really shouldn't use this block at all.
You should really be using a source where you specify only one of position, velocity and acceleration. If that isn't possible, then I'm afraid you'll have to explain why so we can try to understand what you are really trying to achieve here.