I state that I have searched for a long time but I can't find an answer to my problem.
I don't find a Simulink block that has the function of giving in input one step that is worth an x (defined by me) for 5s and 1.1x from 6 to 50s at two models (one linear and one non linear systems)
Usually i use the Step Block to start an initial and final value of the step but the change is almost instantaneous. What block can I use to do this?
Option 1
Use multiple step blocks and add them up. Simple as that.
Option 2
Use the signal builder block.
Related
Currently, I have two delay blocks above each other, where one agent goes through one of the blocks and the other through the other one.
But when I want exponentially distributed values with a mean of 120 seconds, They both need to have the same value always. So they are done at the same time.
You simply need to have the two delay blocks use their own (but with the same seed) random object.
Start off by creating two identical random objects
And have each of the delay blocks use of them of them
Then the numbers they will sample will be the same for every sampling iteration.
See this post for a similar problem
Why do two flowcharts set up exactly the same end with different results every time the simulation is run even when I use a fixed seed?
Not questioning your probably bad design by not using resources, These are the steps to follow to ensure things happen at the exact same time:
1.Create a variable called seed of type long
2.create a cyclic event that runs every 1 minute and has the following code:
seed=(new Random()).nextLong();
3.In both blocks you will use the following code to calculate the exponential distribution:
exponential(120,0,new Random(seed))
I have a system in Simulink/HDL coder (see below image please). I have 3 outputs and 3 inputs. I want my system to run 10 times. After each iteration it should select the outputs and use them as inputs. How I can do that?
Build a loop using a memory and a initial value block for each signal. The memory block allows you to access the previous iteration signal and the initial value block is used to set the input for the first iteration.
A simple example looping back one signal can be found here in the documentation
In your case it would look like this:
To get 10 iterations, set your simulation time corresponding. For example a fixed step discrete solver using 1s sample rate and 9s simulation time.
I have a system with some embedded Matlab blocks where I'd like to perform some actions after a certain amount of time, in this case turn on lights and switches in an interface to which I send signals from Simulink.
The problem is that I thought I'd use "tic"-"toc" and "while" in a Matlab function block to perform these actions, say one parameter becoming 1 after 5 seconds, the following parameter becoming 1 after 12 seconds and so on, but I noticed that tic-toc apparently doesn't work in Simulink for embedded functions.
Is there any similar functions that could be used in Simulink for embedded functions or is there any other way to do this?
Edit: I've tried to get the clock's time as well, but it's a growing value. Is there any way to "lock" the time as a parameter when the block's function is executed?
You shouldn't be using absolute time in an embedded system, which is at least one of the reasons why tic-toc and clock from MATLAB don't work with Simulink Coder.
You should create your own counter, which you start and stop when you need to.
This is pretty easy to do using a Unit Delay and Summation block.
If you need to be able to enable and/or reset the counter then use the appropriate block from the Additional Discrete library.
I have designed a simple simulink and stateflow diagrams on Matlab. It works perfectly! But I have two issues:
1) The model runs too fast. The transition time between two states are amazingly fast that I can not see. I tried to change some parameters, but I was not succeed. What should I change (maybe on Model Configuration Parameters?) to make it slower so we can see the transitions?
2) Currently I just have a constant input. How can I set a series of constants, probably periodic? I assume there should be a special component. I need, like an input of say 0 at time 0, then 1 after 1 minute, 2 at time 3, etc ?
1) I had the same issues with some interactive simulations where the CPU would make them run too fast for the user to interact. Using a Simulink Real Time Execution Block brought the solution, despite it gives heavy CPU load due to the solution it uses. With this, if you define a 10sec simulation, that's what it will last. If you don't want to pass through this burden, just lengthen your simulation, or inspect thoroughly the scopes throughout the whole simulation (disabling point limit in the Scope, clicking the Parameters button and then unchecking Data History/Limit data points to last...)
2) Simulink/Sources/Repeating Sequence. You define vectors of times and the value to output in that time. Keep in mind that the block interpolates the values between two points, therefore, if you want to change from 2 to 3 in T=1s, you have to define two points, one U=2 in T=1s and another U=3 in T=1s. For example, 0 in (0..1), 5 in (1..2), 10 in (2..3) and 15 in (3..4):
Time values: [0 1 1 2 2 3 3 4]
Output values: [0 0 5 5 10 10 15 15]
If you just want to check the transitions, you don't need to make it slower. You can try to use the Debug mode available in Stateflow and you can see how your model works step by step.
The option to slow down Stateflow animation (so that, for example, you can better see the transitions between states during simulation) is under the Display menu in the Simulink menu bar.
In the latest release (R2014b), the option is under Display->Stateflow Animation (as well as under Simulation->Stateflow Animation). (See here for more details.)
In older releases, it's under Display->Data Display in Simulation->Chart Animation Delay (sec) (although, I'm not 100% sure when this option was moved in the menus).
Note that you have to be inside of the chart for these options to be enabled in the menu.
I have designed a signal by using the Signal Builder block in Simulink. During the run of my simulation, the signal builder is to restart depending on the satisfaction of a condition. The condition can be satisfied many times, so, the signal should start from the beginning each time. If I want to put it in another way: You can take step input instead of the designed signal. Step input is to be reset conditionally. How can I make it?
I haven't seen such a functionality built-in Simulink (maybe the newer versions have it?) but here is a workaround:
You can simulate passed time with an integrator that has a Constant block set to 1 as input. The point is that the integrator block has a reset port which you can connect to your condition. So, when your condition becomes true, the integrator restarts a time variable from 0 (which is set in the initial conditions). Beforehand, you need to have your signal saved in something like a Table Lookup block, which outputs the signal as a function of time. Then you connect the integrator output to the Table Lookup block.
Have you tried putting your Signal Builder block in an enabled subsystem? You probably need to set the states when enabling to reset for it to work. Have a look at Create an Enabled Subsystem in the documentation for more details.