Lego Mindstorms Cruise Control

Hi
I have a problem and I am going round in circles
I am trying to create a cruise control in labview for a lego mindstorms robot.
I have got as far as motor control and measuring rotations, however I have hit a wall
I need to work out The transfer function of The motor and then wire up a PID to compensate The power to maintain a steady speed.
1. I have no idea which PID controller to use in labview or how to wire it into my circuit - I have tried a few and I'm lost
2. The output taco is telling me The number of rotations per "second" wrong by a factor of 24 (yes I know odd number)
3. The seconds at ticking over at 24 times The actual rate of time (again odd)
4. I can calculate The speed of The motor but I have no idea how to use this motor speed to calculate The "motor transform" its a new one on me tbh but its something like (1/0.3s)+1 but I'm not sure
5. I have no idea how to add a disturbance in The circuit or where I need to wire The feedback loop into.
All I want to achieve is a controller that will maintain a constant speed no matter The rise or fall of The road for 1 motor
any help would;d be greatly appreciated Thanks

It's never as easy as they make it look on TV, huh?
Have you considered this:
LabVIEW Introduction Course - Three Hours
or this:
LabVIEW Introduction Course - Six Hours
Bill
(Mid-Level minion.)
My support system ensures that I don't look totally incompetent.
Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all.

Similar Messages

Tetrix DC motor control with Lego Mindstorm

Hello, i am trying to finish an ongoing project which endpoint is to be able to graph equations on a white board by using the Lego Mindstorm and tetrix dc motors. THINK OF AN ARM. the problem i have been running into is that i do not know where to begin as synchronizing two tetrix dc motors seems to be impossible. if anyone has anything please let me know thank you.

Hi Lals25,
I found a couple of articles that can come useful for you when trying to synchronize the motors.
Synchronizing Two Motors
How to Calibrate NXT Motors to Travel the Same Distance
Controlling NXT Motors
Best Regards,
amezam

System Identification and Transfer Function of the LEGO MINDSTORM NXT Robot

Can anybody please help with the below question.
Using your LabView interface, input different values of power and record the output value of the number of wheel rotations. You can convert the latter into speed by measuring the diameter of the wheel. Then, type ‘ident’ in the command line of Matlab to launch a graphical user interface for system identification. Using the data collected for input power and recorded speed, you can derive the transfer function for your robot in the Laplace domain.
You will notice that it is possible to approximate the transfer function to a first order system.
Add disturbance to your system such as wind drag, road profile or friction. You might want to model the disturbance as a sinusoidal waveform.
Analyse the system response in LabView in order to tune the response.
Finally, write a LabView program to test your controller.
Set both Integral and Derivative to 0
Increase the value for Proportional controller to 0.5, 0.8, 1, 1.1, 1.3, and 1.5
Select a suitable simulation stop time.
Compare each simulation results and draw some conclusions.
Record the steady-state error. Has it dropped to near zero?
Record the rise time. Has it decreased to less than 0.5 second? And for what values of Kp?
Check whether this response is realistic i.e. a real cruise control system generally cannot change the speed of the vehicle from 0 to 10m/s in less than 0.5 second.
Adjust the gain (Kp) to give a reasonable rise time and add an integral controller to eliminate the steady-state error.
Change both Kp and Ki and see what happens to the response. When you adjust the integral gain Ki, start with a small value since a large Ki can destabilise the response. (Ki =0.001, 0.002, 0.003, 0.004).
Then you need to adjust both the proportional gain Kp and the integral gain Ki to obtain the desired response. Record the values of Kp and Ki that can meet all the design criteria.
Write the PID-feedback control LabVIEW program as described above.
Does it work? Quantify! Show us it is working
Hand in a short report on the PID project on the cruise control of the LEGO MINDSTORM NXT Robot. Your report should contain an introduction to cruise control and uses of PID controllers, a brief explanation of how PID feedback control works. The printout of the Block Diagram and Front Panel of your LabVIEW program should be attached at the end of your report.
Put it all together. There are many questions that can be explored and written up in the result section. Be creative.
Here are some things that may be addressed: Check whether your system can stabilise speed to within 1%. What are the optimal PID parameters that you have found? Can you choose PID parameters to both reach the set speed quickly and also maintain the speed within good accuracy once the system has reached the set speed? Can you control the speed of small steps? Explain your results?

Thanks for that.
DanHarryman wrote:
HI ToolMonkey
You should be able to build control system to do this using PID control VIs. The following paper is a good place to start when working with PID systems.
http://www.ni.com/white-paper/6440/en
Let me know how you get on using some of the functions in this.
Thanks
Dan.H
UKAE

Lego mindstorms: Is it possible to change the fixed user interface size of 1024 x 800 to smaller for use with netbooks?

I teach at a school that is using netbooks next
year - the screen size is 1024 x 576 for one model and 1024 x 600 for another model and color quality is 32 bit. To
our dismay, when we loaded Lego Mindstorms software to test it, we
discovered that the user interface is fixed at 1024 x 800, which means
the control panel at the bottom of the screen is inaccessible on the
netbooks. Is there a way to change the interface size so that we can
use the software on netbooks? This is a serious issue for us! Thanks
for any help.
I posted this question in the LabView for Lego Enthusiasts forum, but noticed that nothing new has been posted by the moderator since 2007. That's why I posted it in an active forum. Thanks.
Message Edited by mwert on 03-27-2009 11:33 AM
Melissa J. Wert
Technology Integration Specialist
Harpeth Hall School
Solved!
Go to Solution.

Hi All,
To echo Dennis Knight and as a FYI for others I refer everyone to KnowledgeBase 44DF7BQ0 How Does National Instruments Support The LEGO® MINDSTORMS® NXT Software And ...
Joshua B.
National Instruments
NI Services
NI Support Resources
NI Training Resources

NI LabVIEW 2009 LEGO MINDSTORMS NXT Module Released!

This software allows users to run code on their computers to control LEGO® NXT Bricks and compile, download, and run LabVIEW code directly to the NXT. The new NXT Module 2009 represents a considerable improvement in features and usability over past versions.
Totally redesigned APIs
Full access to LabVIEW debugging tools
Control NXT bricks either by running code in LabVIEW or compiling and deploying code to the NXT brick
VIs for TETRIX kits are available out of the box
Support for all LEGO® MINDSTORMS NXT 2.0 sensors.
NXT Applications Data Viewer, Piano Player, NXT Multimeter, Remote Control, and Scope
The module can be downloaded here.
Please feel free to ask questions and provide feedback to NI R&D.
Thanks,
Mark
Product Support Engineer - LabVIEW R&D
Mark
LabVIEW R&D

Nice! But I guess that doesn't mean that you will be releasing a free version any time soon... does it.
Oh! BTW (slightly off topic) you should remove the "Select Your Operating System" block on the Student edition cd order form. It just gets peoples hopes up that they might get a mac version.
Andrew
Message Edited by AndrewDudney on 10-22-2009 10:27 PM

Question about Lego Mindstorms Capabilities

Hello, thank you for reading my question!
I am currently working on the creation of a teleoperated robotics lab. for a introductory robotics course. I wish to allow students to control a labyrinth-solver robot via Labview, with the Lego NXT toolbox. A computer server will be connected to the Lego via Bluetooth, and the student communicates with the server via a web browser VI (a web published VI). I am interested on the Lego Mindstorm platform but I wanted to ask some questions about its software capabilities:
*Is it posible via a web VI interface for the student to load a program onto the Lego Mindstorm? My idea is to allow the student to load a VI (or the equivalent of a LEGO NXT ".exe")onto the server, and the server to load the program to the Lego. The Web VI already has some parameters the student can change a simple program execution (see [1]), but I also wanted to give the student the chance of loading their own program for more complicated algorithms.
Thank you in advanced for your time and patience!
[1] Maze Solving Algorithms
http://en.wikipedia.org/wiki/Maze_solving_algorithm

thats the exact error, could it be something of the automathic update of the driver once the joystick was conected through the usb?

Labview 2009 Module Mobile And Lego Mindstorms NXT

Hi
I've installed the mobile toolkit in labview 2009 but when I created a new mobile project I didn't find the NXT Programmings category on menu.....
are they not supported?
I would like to control my nxt with my PDA through bluetooth.
Thanks in advance for help

Hi,
which NXT software did you exacly installed? LabVIEW Module for LEGO MINDSTORMS NXT or LabVIEW Toolkit?
I would like to be sure to have corretcly understood: in a mobile project, the function palette of a VI under a PDA target does not have the NXT palette, correct?
Bye!
Licia

Getting results to the Lego mindstorm NXT brick

In a nutshell, my group and I are trying to use eye movements to control the Lego mindstorm, ie look left turn left look right turn right etc. We will be acquiring the eye movement signals through labview signal express and running those signals into labview to move the NXT robot. We are in need of assistance in both the signal importing into labview and the subsequent utilization of the said signal by the NXT. We already have the NXT toolkit and are able to succesfully run basic programs. The problem we've had is that we need the results continuously imported into the NXT so that we can maintain control of the vehicle. So basically we need pretty close to real time results, sort of like a joystick type of thing. My group members and I have limited experience with labview so any assistance is appreciated.

Hello King945,
Here is a link that walks through sending and reading Bluetooth messages. I have also include a basic NXT Front Panel Control vi. The vi will work if the NXT toolkit is installed and if the NXT brick is wired to the computer through a USB cable. Also, if you integrate the Bluetooth messaging with this vi you should be able to control the NXT using front panel controls through Bluetooth.
Wear
National Instruments
Product Support Engineer
Attachments:
Front_Panel_Steering_Control.vi ‏102 KB

Why does LabVIEW for Lego Mindstorms have 2 Functions Palettes?

LabVIEW for Lego Mindstorms has 2 separate Functions Palettes. One of them appears when one creates a VI (.vi) for a Project (.lvrbt), and it appears to contain Mindstorms NXT functions. The other appears when one creates a stand alone VI (.vi), and it contains functions which are labelled "NXT Robotics" but which appear to be the old Mindstorms RCX functions. For example, the Motor Functions have no Speed or Duration controls. (See Control Palette pictures on the attached Word document.) (NI should be aware that the RCX is no longer sold or supported by Lego.)
If I only want to create a stand-alone VI, how do I access mature NXT functions with which to implement that VI?
Attachments:
NI LabVIEW Function Palettes.doc ‏127 KB

I knew that the NXT could be controlled from a "remote" device (e.g. cell phone), though perhaps "remote" is a poor choice of words given your use of the word "direct" which, as you use it, has the same connotation. I have never run the NXT in the direct mode, nor have any of my team members. The reason I assumed that you had included RCX functions was RCX functions had fewer properties than NXT functions just like your "direct" functions do. I have no idea where the "dual mode" functions are to be found.
I think LVLM has inadequate introductory documentation.I have Gasperi's book, but like NXT-G books, he only gives recipes for robots with different functionalities. LVLM needs a better structural and functional description.
Lego Education is not supporting LVLM (nore is NI, for that matter, at least not very well...it was a lot of work to get to someone who knew what they were talking about). The guys at Lego Education are not in a position to support LVLM. Your guys also asked me to call "Tom Barrowman," Lego's New England sales rep. I didn't call him, but I am betting that he knows even less.
I understand why NI doesn't want to put the support bucks into LVLM. The license for LV cost $2500/year, and I bought LVLM for $100. LVLM was intended to be an introductory product for people (kids) who might become NI customers someday, but if those kids walk off in disgust because they can't figure out how to use LVLM, NI's investment in it will have been for nothing.
Attachments:
For Ethan.doc ‏66 KB

Regular Labview's VIs unable to execute in lego mindstorm labview module

Hi,
I'm trying to create a block diagram that using vision aquisition in Labview module to detect my eyeball motion for robot direction control. It's success to run the block diagram.
At the same time, i also using lego mindstorm labview module to create block diagram for the EV3 robot.
But when i interface the two algorithms in the lego module, it can't run the block diagram due to the lego module can't run the other VIs? Because the error state that Mathscript, Vision Aquisition, IMAQ and others, all are not supported to execute.
Any suggestion or other ways to solve this problem?

Did you install Lego Mindstorms software and trying to use LabVIEW VIs in there? Or do you have a regular LabVIEW license with the Lego Mindstorms add on library installed?
Lego Mindstorms is a special version of LabVIEW with restrictions like not being a general development environment. It can only run VIs that are specifically compiled to run for Lego Mindstorms and I suppose only NI has the necessary tools to do that.
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

LEGO Mindstorms 2.0 crashes at startup when LabView Signal Express is installed first

When NI Circuit Design Suite Education Edition is installed first in a computer and the LEGO Mindstorms software second, the LEGO Mindstorms software doesn't work, it reports the following:
Error: A required file is broken
Possible Solutions: Reinstall the LEGO Mindstorms NXT Driver (tried but doesn't work)
Error code: 1003
Ordinal not found
The ordinal 18 could not be located in the dynamic link library NIVISV32.dll
Error loading "fantom.dll"
The operating system can not run %1
On other computers the LEGO software starts running, it displays part of the initial screen and then a small window opens saying that the Mindstorms software has has an error and that it will close. The previous report doesn't show.
If LabView Signal Express is uninstalled and then the LEGO software reinstalled, the LEGO software works.
I've dowloaded and installed new and old versions of the NIVISV32.dll and this doesn't correct the problem. I went as far as version 4.20 of the dll because it is dated in 2007 and the dll file installed by the LEGO software when it works is also dated 2007, but if I install the dll without uninstalling LabView Signal Express, the LEGO software continues not working.
Please advice how to correct this problem without having to uninstall LabView Signal Express first. If the LEGO software is installed first, is LabView Signal Express going to use and not to replace the old 2007 version of the dll installed by the LEGO software? Is there any LEGO software update that corrects this problem?
I repeat: I know a solution is to uninstall LabView Signal Express, install LEGO Mindstorms and then reinstall LabView Signal Express but I have 60 computers already cloned and deployed with this problem, so I don't want to go to this long process to fix the problem. The computers are using Windows 7 and problems happen on both the 32 and 64 bits versions of Windows 7.
Any ideas???
Solved!
Go to Solution.

I couldn't reproduce the error either, but in our x86 computers this problem appeared after several months; we used LEGO Mindstorms last time in Summer 2011 without any problems and just three weeks ago when we were checking the computer for our Summer 2012 classes if when we noticed the problem. I’m still going to try to reproduce the error in an x64 computer where the problem appeared immediately.
Anyway, I’m attaching a word file with images of captured screens where you can see the error reports generated by LEGO Mindstorms and a series of steps uninstalling and reinstalling these program plus LabVIEW, until LEGO Mindstorms finally works after having uninstalled all traces of LabVIEW.
Images can be expanded and zoomed in to a better view of the details and if I can reproduce the problem in an x64 computer I’ll let you know.
Please see if you can find out something based on the images I’m sending.
Thank you.
Attachments:
LEGO PROBLEM.doc ‏3129 KB

Error while configuring weblogic workshop application to cruise control.

Hi,
I have a web application which is created through weblogic workshop 9.2 and want to configure it to cruise control.
In that process, i had to change the web app to ear application and created build.xml for configuring it to cruise control
but I'm getting the following error.
It would be great if anyone could resolve the issue.
copyConfiguration:
[echo] No configuration directories specified
createWorkspaceXML:
[echo] Running createWorkspaceXMLFile
checkout:
build:
[echo] Compiling using /home/cocbad/wlp92-projects/SearchApp/src/SearchApp/SearchApp/build.xml
init.env:
check.params:
check.versions:
init.typedefs:
[echo] Using Workshop Libraries located in the "../SearchApp/ant-build-lib" directory.
Trying to override old definition of task for
Trying to override old definition of task jspc
init:
[mdimport] The workspace is missing the definition of the "BEA WebLogic Server v9.2 JRE" Java VM, which is referenced by a project.
BUILD FAILED
/home/cocbad/wlp92-projects/SearchApp/SearchApp_build.xml:20: The following error occurred while executing this line:
/home/cocbad/wlp92-build/build_app.xml:44: The following error occurred while executing this line:
/home/cocbad/wlp92-build/build_tasks.xml:110: The following error occurred while executing this line:
/home/cocbad/wlp92-projects/SearchApp/src/SearchApp/SearchApp/build.xml:74: Metadata import failed!
Total time: 8 seconds
Thanks & Regards,
Swapna

Hi,
Issue is resolved.
Value for property "aia.jdev.lib.dir" was missing in my build.xml.
Regards,
UJ

How do you add a third party sensor to LabVIEW for Lego Mindstorms?

I recently purchased an IR Sensor from Mindsensors (DIST-Nx-Long-v3) which I need for a SLAM (Simultaneous Localization and Mapping Application) that I am developing using the LabVIEW for Lego Mindstorms software. I installed the Mindsonsors IR Sensor, and it works under NXT-G and RobotC, but am having trouble finding a way to get LabVIEW for Lego Mindstorms to install the sensor.
The Mindsensors website gives the following instructions for installing the IR Sensor:
1.Unzip the folder mindsensors.com LVEE
2.Open a blank vi in LVEE
3.On the Block Diagram Go to Tools->Advanced->Edit Palette Set...
Unfortunately, on the Block Diagram of the LabVIEW for Lego Mindstorms, there is no "Advanced->Edict Palette Set" under Tools.
As an alternative, I consulted the documentation that came with LabVIEW for Lego Mindstorms. The Schematic Editor of LabVIEW for Lego Mindstorms lists several sensors, i.e. the Lego Mindstorms sensors and several Hi-Teach (HT) sensors, but there are no procedures listed in the documentation for adding other third party sensors to the Functions Palette.
So, how does one go about adding a third party sensor to LabVIEW for Lego Mindstorms?

Hi Ethan,
As you can see from my Word document, I am a little light on the proper terminology. That's because LVLM comes with inadequate documentation.
I have already followed your recommended protocol for installing a 3rd party sensor (in fact, its the protocol recommended by Mindsensors) with the application set in the Remote Mode (.lvrbt), and it does create a sub-palette with all the Mindsensors functions on it. But when I drag the Mindsensors icon to the Block Diagram and select "Distance Sensor," the Distance Sensor (an IR sensor) doesn't work (even though the Mindsensor's Distance Sensor does work with NXT-G, RobotC and LVLM under other circumstances (see below)).
If I repeat the above process with the application set in the Direct Mode (.vi), I also get the sub-palette with all the Mindsensors functions on it. When I drag the Mindsensors icon to the Block Diagram and select "Distance Sensor," the Distance Sensor does work.
What I need for my mapping application is for the Distance Sensor to work in the Remote Mode. I called NI tech support and the first engineer told me to simple drag the Mindsensors Functions (.vi) onto the Block Diagram. I did this, but when I selected the Distance Sensor, the icon appeared, but the sensor did not work. Since I have no idea what's under the hood of the vi or a function, I assumed that simply dragging the vi/function onto the desktop didn't install the vi/function properly. I went back to the Applications Engineer, and he confessed that he did not understand the LVLM product.
My frustration is being punted to new people, none of whom so far (other than you, of course) understand LVLM.

Connecting LEGO mindstorms NXT to my computer

I am trying to learn Labview using the LEGO mindstorms NXT robot. I installed Labview 2009 and started working, but when I open the NXT terminal in the NXT module it claims that the NXT is not connected although it is (via USB). Any ideas ? Could this have to do with the fact that I am using Windows Vista ?
Thanks

This article is intended to indicate the installation and configuration process between LabVIEW and educational robot Lego Mindstorms NXT wirelessly, this will enable LabVIEW developers in having a mobile platform for the development of projects and autonomous robots, we need to install some programs the computer:
https://decibel.ni.com/content/docs/DOC-32448
Atom
Certified LabVIEW Associate Developer

LabVIEW Toolkit for LEGO MINDSTORMS NXT in Windows Vista

Anybody knows how install LabVIEW Toolkit for LEGO MINDSTORMS NXT with Windows Vista?. Installing it gives me an error that says 'The windows installer is corrupt. To attempt to resolve the issue, please register the engine by running regsvr32.exe on msi.dll'. But it doesn´t work.
Thanks in advance

The work around for this issue is to install each of the MSI files setup.exe calls when running the installer. I was able to reproduce this issue for the 1.0 toolkit I was unable to do so for the 2.0 toolkit. This being said the instructions bellow are for those of you who are running into this issue with the 2.0 toolkit.
Listed bellow are the MSIs you will need to run (shown here at their default location after the self extracting EXE has been run). You should run these MSI in the following order.
C:\National Instruments Downloads\LabVIEW\7.1\LabVIEW NXT Toolkit\2.0\Products\MetaUninstaller\MU\MetaUninstaller.msi
C:\National Instruments Downloads\LabVIEW\7.1\LabVIEW NXT Toolkit\2.0\Products\MDFSupport\MDF\MDFSupport.msi
C:\National Instruments Downloads\LabVIEW\7.1\LabVIEW NXT Toolkit\2.0\Products\MDFSupport\MDF\EULADepot.msi
C:\National Instruments Downloads\LabVIEW\7.1\LabVIEW NXT Toolkit\2.0\Products\LVLEGONXTTK\LVLEGONXTTK\LVLEGONXTTK.msi
C:\National Instruments Downloads\LabVIEW\7.1\LabVIEW NXT Toolkit\2.0\Products\LVLEGONXTTK_LV71\LVLEGONXTTK_LV71\LVLEGONXTTK_LV71.msi
C:\National Instruments Downloads\LabVIEW\7.1\LabVIEW NXT Toolkit\2.0\Products\NXT_Driver64\LegoMindstormsNXTdriver64.msi
A similar procedure can be used to install the 1.0 toolkit if need be. You can get the install order from the parts from the [Parts] section of the setup.ini.
Mark
LabVIEW R&D

Lego Mindstorms Cruise Control

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