How to connect two robot arms by sharing one manipulator in webots - robot

I am working on a project that two robot arms control a rope to play a toy. I want to first simulate it in webots. Each robot arm has a stick as the end-effector. And there is a rope connecting both the two sticks. However, in webots simulation, each robot(let's say UR5e) should be set as an independent node. How can I connect them using a rope?

I would use a Connector node to connect the end of the rope to the second robot stick.

Related

is there any specific sensor nodes in ns3 simulator? what types of sensors does ns3 have?

i want to do a simulation on IoT sensors in ns3. does ns3 has any specific sensors such as temp sensor or other sensors? or it just specifies as sensor nodes?
There are no IoT-type sensor classes in ns-3 at the moment, but it appears there was desire for such functionality in 2013.
As an aside, ns-3 is a network simulator. It's not meant to simulate specific devices – rather, it simulates the network traffic of devices. If you can determine the traffic pattern of a device, than you can build an Application that generates this type of traffic, and install that Application on a Node. You may find inspiration for how to wrap your own Application by looking at the existing Applications. You might also be able to mimic the traffic pattern of IoT devices using an existing Application.

Mindstorms IR Sensor Measurement compatibility issue

I am using Mindstorms and build a Robot with two Motors and a IR Sensor.
1) I made a program which lets the Robot follow a IR signal and stops when reaching it.
2) I made a program to remote control the robot with the IR control.
Both program work. But when combining them, program 1 does not work anymore.
It gives eratic results from the IR sensor. It seams the detecting a IR-Button is not compatible with measuring the signal in the same program. Anyone has similar experiance or know how to deal with it?
This is the program which works:
Introducing another Selection around it which senses a IR Button does not work anymore:
The result is, that the program follows to the right section, but the IR measurements of distance and directions give random results.
Anyone has any Idea?
If you have already tried another sensor and there is still a problem it could possibly be a bug with the software. I would post your example on the the NI MINDSTORMS support board so that they can look into the bug.
http://forums.ni.com/t5/LabVIEW-for-LEGO-MINDSTORMS-and/bd-p/460

Arduino project using infrared sensor and usb communication

I am planning on doing a small arduino project and would like to know if what I'm thinking would work with a regular arduino board. I'm thinking of buying an Arduino Uno for my project, along with an IR LED and an IR sensor. So here's what I want to go with this:
I want to point the LED towards the sensor, so that the sensor is always detecting light. Then', I'll start "cutting" that light (say, with with my hand) several times. I want the arduino program to time the intervals between the times the light is "cut" and send these times to my computer via USB, so I can process this data.
I've seen many people talk about serial communication between an arduino board and a computer, but I'm not sure how that works. Will it use the same usb connector I use to upload programs to the board, or do I have to buy anything else?
EDIT: tl;dr: I guess my question, in the end, is twofold:
1) Am I able to "talk" to my computer using the built-in USB connector on the board, or is that used solely for uploading programs and I need to buy another one? and
2) Is this project feasible with an Arduino Uno board?
Thanks for the help!
Yes, your project is very feasible.
You use the built in USB connector to both program the device and communicate with it. Check out some examples on the Serial Reference Page
For reading the sensor, you'll want to use either a digital or analog input. For a digital input, you'll likely have to external components to control the light threshold, but it will provide a simple yes or no if something is in front of it. With an analog input, you can use a threshold in code to determine when your hand passes.
Timing can either be done on device with the Millis() function or on the connected computer.

Controlling simple relay switch via USB

I'm looking to control a mains powered light from a simple relay switch connected via USB to the computer.
The relay switch isn't even a USB device, it's just a simple switch that requires the USB voltage to turn it on. When the voltage drops below a threshold, the switch will turn the light off.
My problem is that I can't control the power output of a USB port. I'm happy to do it using any language on Windows or Linux (but preferably Java because I'm used to it).
Unfortunately, in most cases you cannot control the power supply to the USB port. The power supply is usually hardwired through, and not switchable in software. You can send a reset to a USB device, but that won't work in your case.
There are a number of projects on instructables that do similar to what you describe, but unfortunately they seem to either be quite complicated or require expensive parts.
EDIT: There is actually a product currently in the news which would do want you want, but it doesn't appear to be shipping yet: http://www.pwrusb.com/
EDIT (again): Apparently you can do this with some usb hubs. This post sugggests the Linksys USB2HUB4 is one that works.
EDIT (and again): Apparently there are a number of similar questions, but there don't seem to be any more useful answers:
https://stackoverflow.com/questions/405269/custom-usb-device-that-disables-power-to-usb-devices-plugged-into-it
Power off an USB device in software on Windows
Is there software or code to alter USB power output
Can I write a program that swiches USB on/off
Most of the USB to Serial or USB to RS232 $10 converters support hardware handshaking. Use one of those as a single channel digital io.
Connect your transistor that will drive the relay to DTR on the converter board and command DTR ON/OFF with the converters driver.
A 2N7002 is a good transistor to use (FET actually) since it will work from 3V and doesnt need any resistors anywhere.
Here is a complete solution.
It uses an Arduino board, with a USB connection, (and Uno for example) to control the relay and combines this with pfod (Protocol for Operation Discovery) www.pfod.com.au which will let you control the board/relay from either the Arduino IDE SerialMonitor, or a terminal window (TeraTerm) or a Java program. The message protocol encloses commands in { }, think simplified html for micros, and provides numerous screens, menus, sliders, text and numeric inputs, etc. A detailed protocol spec is available
See Garage Door Remote for a detailed example, with full Arduino code and an example of controlling the relay from TeraTerm as well as the Arduino IDE SerialMonitor.
There is also an Android app, pfodApp, which will do general purpose control via bluetooth, or wifi/internet with 128 bit security. The pfodApp does all the Android stuff, you only need to code some simple strings in your Arduino code to get any menu system you want. See www.pfod.com.au for numerous examples.
You need a USB-GPIO microcontroller:
Adafruit FT232H (about $15)
Arduino Nano ATmega328 (about $7)
See this answer
I would suggest placing a separate Raspberry Pi unit with a wake-on-lan feature activated so you can ping it off and on.
You could do it by combining these two products from Pololu, for about $25:
Micro Maestro (assembled)
Basic SPDT Relay Carrier with 5VDC Relay (Assembled)
The Maestro is mainly a servo controller but you can set any of its channels to be simple digital outputs instead. The output can be controlled from the Maestro Control Center software or you can write your own software. A digital output from a Maestro is suitable to turn on the relay on the relay carrier. The relay could be powered from USB through the Maestro; I think it draws about 100 mA of current so that probably will not be a problem for most USB ports, though it would not be USB-compliant because the total current drawn by the Maestro and the relay would be over 100 mA. You could supply your own power source for the relay if you are worried about that.

How to have a computer flash a light

I'd like to have an application monitor written in C# monitoring a set of Forex trading positions. It would be connected via USB to a real set of "traffic lights" sat on a desk which it would use to indicate system status. Can anybody suggest a good solution?
Normally I'd say parallel port or some other such thing, but if you've got your hopes up for USB, then definitely have a look at the Arduino. It's a very low cost microcontroller that can run standalone, or can talk to a PC through a number of flexible interfaces (including USB).
It is extremely popular with the hobbyist community, and as such, there are a number of entry-level projects to get one started with the device. Price on Sparkfun is $35 USD for a fully assembled USB-enabled version.
I have used the concepts in this CodeProject article to successfully light up LEDs.
It might meet your requirements if:
You can use parallel port instead of usb (or maybe usb to parallal cable/dongle)
You are ready to tackle some soldering and simple electronic tinkering
You can modify the vb code to monitor your status
As the author mentions in the article, you can destroy your computer's parallel port (and worse!) if you are not very careful.
In addition, a good engineer would insist that you isolate the lights from the port to further protect the computer. (relays, triacs, opto isolators, etc.)
That being said, it does work!
The easiest solution is to buy a USB traffic light, rather than building one yourself. E.g. USB Ampel. With a simple API included, it would probably be much easier.
Traditionally people have used the X10 automation framework for this kind of thing. People at my company use it to control lava lamps to indicate the status of our continuous integration build.
There's a pointer over at How does one get started writing applications that interact with x10 protocol?
One step further is to build something yourself using a microcontroller platform like the Arduino. Some examples of what is possible with the Arduino platform are available on the Arduino Playground page.
An article on how to make traffic lights using an Arduino is available at Instructables.
Channel9 has a video from the Microsoft PDC showing how some developers use a "Build Bunny" for something similar: PDC2008 ShowOff Entry: Brian the Build Bunny
There's also more information and source code here.
Try using simple usb experimentation interfaces such as Phidgets (Www.phidgets.com) or the Velleman k8055 USB experimentation board (http://www.velleman.be/ot/en/product/view/?id=351346).
We used this product at my last job to control a set of revolving traffic lights when a build would break on our CI server. The Ethernet is nice so that you are not limited to the 3M range of USB and it is as easy as opening a TCPClient to port 10000 and sending a "1R1\r".
http://www.6bit.com/products/smartrelayE.php?products_id=33