# Tag Info

6

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 thus un-tune) the tuning mechanism. Worm gears are nice in that they offer generally pretty huge reductions in speed, with a huge increase in torque. This leads ...

6

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 good design decisions. The fuse is actually a PTC. The benefit is when you eventually accidentally short battery to ground in your project the PTC protects but ...

5

I must agree with the other two answers, however the main issue is that you do not have enough voltage into your regulator (I see from your comment to Ian that you are using a Pololu D15V35F5S3 Regulator). If you refer to the Pololu D15V35F5S3 Product Description, down at the bottom you will find the following graph: Looking at the red line for 5V output: ...

5

It sounds like you're experiencing a "brown out" caused when the excessive current draw from the battery causes a drop in the supply voltage. This is due to the fact that batteries have internal resistance (a.k.a output impedance). In this example, if the load drops to $0.2\Omega$, the internal resistance of the battery will cause the output voltage to be ...

5

Since you're running directly from a battery I would say it's safe to just add as much decoupling (in other words caps across your input power) as possible, since the only real downside (that I think is relevant to your setup) to adding a lot of capacitance is increased in-rush current (since the capacitor naturally acts as a short-circuit during charge-up). ...

4

Is it possible? Certainly. Is it worthwhile? Depends on how sensitive you need it to be. Dog urine has a strong ammonia component (or maybe it's just my dogs that stink so bad) that could be used as the primary analyte to look for. Unfortunately, calibrated electronic ammonia sensors are expensive. I was actually looking into this just a week ago because I ...

4

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 on. Robots are interdisciplinary systems by definition, and you will always need a team with a broad skill-set to build one. That being said, there are places ...

4

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 interpreted code in such applications: Compiled code usually takes up less space. So you can have more code in the same amount of space. Compiled code usually ...

3

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 rises, the EMF rises too. What does an ESC ? Basically, it hashes the input voltage to generate the expected output voltage. So, what is this decreasing ...

3

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 same name, and another for displaying principle of operation. A portioner is a disc or other shape that has a hole. The hole is sized to contain the correct ...

3

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 about 10cm, I.E. successive samples are randomly distributed in a 10cm diameter cloud around the true location. Also, the radio signal needs a clear line of sight ...

3

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 also will ramp up (and down) differently with sudden changes in control signal. As you probably already know, if one rotor of a multirotor vehicle has more (or ...

3

I think you are mixing the idea of BEAM robotics (why that, I prefer to not use this term), with analog electronics. Analog circuits are in major applications more fast than a micro processed one, that have a clock to process instructions. The "problem" with analogs is in part with noise, but early computers are made analog, operational amplifiers are made ...

3

If we are defining BEAM robots as ones that do not use microprocessors, and only use analog circuits, then yes I think it is possible, but not practical. A microprocessor is essentially a programmable circuit, and if we define what we want our robot to do, then we should be able to program the hardware (by building the proper circuit) without needing a ...

3

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 very hot without melting or oxidizing. But I don't need or want the heating elements in my artificial muscles to be red-hot. I would like to be able to ...

3

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 looking for; this would have the advantage that you could add other circuits to the panel that you may need for your project. Remove the boards from the wheel modules ...

3

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 earliest paper was written in 2009 and has a nice plotchart of the Electro-Magnetic Field on page 8 Powerline perching with a fixed-wing UAV for directing the UAV in ...

3

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.youtube.com/watch?v=MvRTALJp8DM Dynamic system Harmless/secure distance present day wireless charging methods: use low energy harvesting drone or an ...

3

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 trips to be thrown, amplifier shutdown or voltage drops and loss of control. One option is to try to reduce the stress on the motor and amplifier. For instance ...

3

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 supply voltage dropping below the minimum rated voltage for the motor controller. The master board was fine as the brownout voltage was still above that minimum. ...

3

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

3

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 the input to your system is. Maybe it's speed, or thrust, or acceleration. It's the thing that is exciting your system. I'm looking at your equations and I don't ...

2

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 radio transmitter - 6 Vex Motor Controller 29's - 6 DC motors, Stall current @ 2 amps, 6V To avoid using complicated electrical stuff (no messing with ...

2

MOOCS are so popular nowadays, that I'm not sure you haven't check it out. Anyway, let's give it a shot. Please, have a look at this courses: edx.org https://www.edx.org/course-list/allschools/electronics/allcourses www.coursera.org You can also check out www.coursera.org. it's similar to mentioned above. MIT OpenCourseware And last but not least, you ...

2

BEAM robots are generally simple circuits that exhibit some emergent behavior that (superficially) mimics biological behavior. Generally speaking, there is no hard criteria for what a BEAM robot must accomplish -- they are not built to handle tasks that require reliability or repeatability. While BEAM robotics should in theory be able to handle any tasks ...

2

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 recognizing and extracting range / angle information from AR markers are well developed, and included in the Robot Operating System. Now, you won't need to actually use ...

2

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 past we see that many contributions are capitalized by people of diverse expertises, ranging from machine learning to even psychology (because robotics is ...

2

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 bar/score indicator across the middle of the table - just put the camera in there looking down. Check out the OpenCV library and webcam tracking tutorials ...

2

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

2

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 motors are "rated" for 12V. Is that a maximum, minimum, or nominal voltage? I'm assuming they're rated for DC power, but there are some low voltage AC motors. ...

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