6 votes
Accepted

What actuator types exist that remain locked in their last position like hydraulic piston?

Actuators that use a worm gear can't generally be back-driven; these are the same gearing mechanisms that let you twist a guitar string to tune it without the tension being able to back-drive (and ...
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6 votes
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iRobot Create 2 - bypassing fuse for serial port power, other current limitations?

First the disclaimer - if you modify the robot by defeating or replacing the protection features you're on your own. That being said here is some useful information that will hopefully help you make ...
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4 votes

Help for Cracking Robotics Interview

As a professional robotics engineer (with an Electrical and Computer Eng bachelors, although I focused more on the CE side), this depends entirely on what aspect of a robotic system you'd like to work ...
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4 votes
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Are robot's codes usually compiled or interpreted?

Robots tend to be portable devices powered by batteries. Portable battery operated devices tend to use embedded processors with limited power and memory. Compiled code has several advantages over ...
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  • 451
3 votes

Create 2: Wheel interface board replacement

Here are a few ideas: Buy 0.050" spacing prototyping board. For example, here are some possible boards that could work on Digi-Key. Use a PCB prototyping service and fabricate the board you're ...
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  • 952
3 votes
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Electronic circuit for heating nylon fishing line muscle

what metal should I use? Copper wire works better than nichrome wire, according to Homemade Artificial Muscles IV. That says Nichrome is used in places like your toaster mainly because it can get ...
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  • 4,375
3 votes
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Voltage rpm relation

You can't understand this because you don't know what you observe. The electromotive force (EMF) of your motor is proportional to its speed (the ratio is called Kv). So, when the speed of your motor ...
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  • 231
3 votes
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Dispensing precise quantities of liquid and powder

So here's a system commmonly used in portioning substances, but I don't know what it's called for you to look it up (sorry). I've included two pictures, one for reference for us to call things by the ...
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3 votes
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Do simple, non-sonic, omni-directional rangefinding beacons exist?

Yes, there is such a system available today, ScenSor from DecaWave: These tags can measure their distance from base stations using the time of flight of radio packets. They have an precision of ...
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  • 6,337
3 votes
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Why can't i use different ESCs together on a multirotor?

Ideally, when you raise the collective all the way up, all the ESCs put out their max power and the quadcopter goes straight up. Different ESCs will end up producing different maximum thrusts; and ...
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3 votes
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Can high voltage power lines provide a super highway for drones?

Sure, a drone can land on a powerline. That's a standard task like the "peg in hole problem" for robotarms. The aim is to maneuver a UAV near to a highvoltage line and eating all the energy. The ...
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3 votes

Can high voltage power lines provide a super highway for drones?

I think yes it can but how? My options are here: Static system for conventional systems It should stand or hang to line/pole/special place like birds. Please watch video for an example: https://www....
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  • 1,084
3 votes

How to deal with current spikes due to fast direction-switching motor commands?

As explained in my answer to What is stall current and free current of motors? when switching direction on a motor, you can end up drawing more than the maximum normal current rating. This can cause ...
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  • 4,088
3 votes

How to deal with current spikes due to fast direction-switching motor commands?

I've experienced a similar problem before. For me, the root cause was insufficient battery power. When my motor tried to draw peak power it caused the battery supply bus to brown out. This led to ...
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3 votes

Electronic Speed Controller

It depends on the voltage. Say you are running 12V: 1820W / 12V = 151A With a 24V system: 1820W / 24 = 75A
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3 votes

Control signal of an LQR Controller

I've gotten stuck in a rut with grasping what the "U" control signal actually refers to in the physical system But you've written what it is already! $$ \dot{x} = Ax + Bu $$ It's whatever ...
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2 votes

What are the options for a thin light source (e.g. LED)?

What's wrong with an actual LED? Size 0402 is about your size spec. This one is $0.06 at 10k quantity.
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  • 206
2 votes

Strategies for managing power on electrical systems for mobile robots

You asked for examples of existing robots. I once built a 6 wheeled rover robot with the following components: - 2 homemade paperclip touch sensors - 2 Arduino Unos - a 3.3V digital compass - a 5V ...
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2 votes

Do simple, non-sonic, omni-directional rangefinding beacons exist?

You could use AR markers attached to each robot or in known locations around the room. In fact, this is how it is typically done in research for indoor, multi-robot systems. The libraries for ...
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2 votes
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What is the scope of Electronics Engineering in Robotics/Automation?

Robotics can be currently broken down in three main components: mechanics, electronics and then ... comes the fuzzy part, that is where there was used to be just computer science while in the recent ...
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2 votes
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Air hockey with a robot as an opponent

A well lit, perfectly circular object on a contrasting background, like a puck on an air hockey table, is pretty much the ideal use for webcam object tracking. A classic air hockey table has a light ...
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2 votes
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Powering my robot with 12V battery which is charged by a gas/petrol generator while the robot is operating?

The alternator in a car is constantly charging the 12V battery while the car is running, which is to say battery-wise you shouldn't have any issues. Several things could be meant when you say the ...
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2 votes

Electronic circuit for heating nylon fishing line muscle

As far as how to heat the nylon muscles, one of the articles that you have linked to provides a number of methods for doing so. The two most promising from an experimental perspective are submersing ...
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2 votes

How to calculate the current consumed by a brushless motor on a quadcopter

n = Kv * Vin only when there is no load on the motor. When there is a load on the motor, like from a propeller, you will need to be a bit more clever. For a DC motor (which BLDC motors approximate by ...
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2 votes
Accepted

How difficult it is to build simple robots (for example Line follower) using raspberry pi and ROS?

It is not extremely difficult to achieve this. It is probably a great way to learn after you complete the main ROS tutorials. Using ROS will get you free joystick or keyboard teleoperation of your bot ...
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  • 106
2 votes

Neural Nework code or library for MSP430G2553 microcontroller

One page linked says the algorithm is fine for the ATmega328's 2KB of SRAM, another is for the ATmega2560's 8KB of SRAM. Your MSP430G2553 has 0.5KB of RAM, so I think that's the primary reason you ...
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2 votes

Electric vs. internal combustion engine for propulsion

Q: What are the main differences between electric motor and internal combustion engine for an ATV-sized mobile robot platform in terms of functionality, implementation difficulty ("RC" conversion, "...
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2 votes

I need the scheme of iRobot Create 2

The schematic for the main board on the iRobot Create 2 is currently not available. It is advised to remove the plastic top cover before drilling into the electronics below. (This is good practice for ...
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  • 952
2 votes
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Raspberry Pi and Buzzers: Simple solution

For a beginner, it is always best to follow / copy an existing example. Fortunately, a tutorial about connecting a sound device to a Raspberry Pi and parts are available here. Also, there is a ...
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  • 451
2 votes
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Calculating the resistor for a buzzer

Without a more detailed spec sheet I can't say for sure, but this is my understanding: The buzzer has a self-drive circuit is rated for input 6V max, at which point it will pull 45mA and oscillate at ...
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