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An artificial muscle fiber made from fishing line and sewing thread that is stronger the a biological muscle fiber. It is all about the polymers.
http://medicalxpress.com/news/2014-02-powerful-muscles-fishing-line-thread.html
http://medicalxpress.com/news/2014-02-powerful-muscles-fishing-line-thread.html
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John Connor
Lifer
- Nov 30, 2012
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Still there is interesting stuff coming up :
phys.org
Excerpt form the text :
"
Robotics is just one potential use for the material, which is made with cellulose nanofibers (CNFs) derived from wood. The technology also presents possibilities in medicine and biochemical production.
The results were reported in Advanced Materials by researchers at KTH Royal Institute of Technology.
Unlike robotic muscles that expand with the power of pressurized air or liquid, these hydrogels swell due to water movement driven by electrochemical pulses, says Tobias Benselfelt, a researcher at KTH Royal Institute of Technology's Division of Fibre Technology.
The material's key components are water, carbon nanotubes as a conductor, and cellulose nanofibers that are sourced from wood pulp. Though the material is a hydrogel, it appears as strips of plastic when it is combined with carbon nanofibers.
The material's strength comes from the orientation of the nanofibers in the same direction, just as in wood grain. "Nanofiber hydrogels swell uniaxially—on a single axis—generating high pressure," Benselfelt says. "A single 15 x 15cm piece can lift a 2-ton car."
"
Tiny brick-busting 'muscles' for miniature robotics are sourced from wood
Wood is the source for a brick-breaking mini robotic muscle material developed by researchers in Sweden and Germany. The material—a specially-developed hydrogel—can shape-shift, expand and contract on demand when controlled with electronic impulses of less than 1 volt.
"
Tiny brick-busting 'muscles' for miniature robotics are sourced from wood
Wood is the source for a brick-breaking mini robotic muscle material developed by researchers in Sweden and Germany. The material—a specially-developed hydrogel—can shape-shift, expand and contract on demand when controlled with electronic impulses of less than 1 volt.Robotics is just one potential use for the material, which is made with cellulose nanofibers (CNFs) derived from wood. The technology also presents possibilities in medicine and biochemical production.
The results were reported in Advanced Materials by researchers at KTH Royal Institute of Technology.
Unlike robotic muscles that expand with the power of pressurized air or liquid, these hydrogels swell due to water movement driven by electrochemical pulses, says Tobias Benselfelt, a researcher at KTH Royal Institute of Technology's Division of Fibre Technology.
The material's key components are water, carbon nanotubes as a conductor, and cellulose nanofibers that are sourced from wood pulp. Though the material is a hydrogel, it appears as strips of plastic when it is combined with carbon nanofibers.
The material's strength comes from the orientation of the nanofibers in the same direction, just as in wood grain. "Nanofiber hydrogels swell uniaxially—on a single axis—generating high pressure," Benselfelt says. "A single 15 x 15cm piece can lift a 2-ton car."
"
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James Bruton - Robotics
"
Former toy designer, current YouTube maker and general robotics, electrical and mechanical engineer, I’m a fan of doing it yourself and innovation by trial and error.
"
The omniwheel :
General youtube site :
"
Former toy designer, current YouTube maker and general robotics, electrical and mechanical engineer, I’m a fan of doing it yourself and innovation by trial and error.
"
The omniwheel :
General youtube site :
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So much fun to see. The bipedal robots form starwars in real life at Disneystudios. No animation.
The general site : https://sites.disney.com/waltdisneyimagineering/
The general site : https://sites.disney.com/waltdisneyimagineering/
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And following post #32 about waltdisneyimagineering :
Some nice youtube films :
From the text accompanying the video :
"
Designing a bipedal robotic character with impeccable balance is impressive, but simply isn’t enough when you consider Disney characters strut, prance, sneak, tromp, shuffle, hustle, saunter or meander. Disney Research recently unveiled a new robotic character prototype that combines procedural animation, modular hardware, and reinforcement learning to be able to design and program a walking character capable of these unique gaits and traits. Even more impressive? They can do this within months, not years! The ability to have a new robot design learn to imitate artistic motion in a simulation environment before it’s being built advances Imagineering’s innovation pipeline … and we can’t wait to see what more can be done with this exploration!
"
Some nice youtube films :
From the text accompanying the video :
"
Designing a bipedal robotic character with impeccable balance is impressive, but simply isn’t enough when you consider Disney characters strut, prance, sneak, tromp, shuffle, hustle, saunter or meander. Disney Research recently unveiled a new robotic character prototype that combines procedural animation, modular hardware, and reinforcement learning to be able to design and program a walking character capable of these unique gaits and traits. Even more impressive? They can do this within months, not years! The ability to have a new robot design learn to imitate artistic motion in a simulation environment before it’s being built advances Imagineering’s innovation pipeline … and we can’t wait to see what more can be done with this exploration!
"
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Some handy websites and ideas for robotic vision :
www.roborealm.com
opencv.org
www.robotroom.com
Robotic Machine Vision Software
Home
OpenCV provides a real-time optimized Computer Vision library, tools, and hardware. It also supports model execution for Machine Learning (ML) and Artificial Intelligence (AI).
opencv.org
Polarizing Light Filters for Beacon Navigation - Robot Room
Beacons emitting horizontal and vertical polarized light through polarizing film can be sensed by a robot for navigation. This article describes polarized light and a machining a test apparatus for aligning filters.
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An old thread about pattern recognition systems and a lot of ideas about how for example pattern recognition, vision and depth perception can be implemented.
forums.anandtech.com
Pattern recognization algorithms
So I have a picture coming in. I want to have an AI that can see the picture, tell if it is part of another master picture, and then output the coordinates of that spot.. The picture can be rotated, colors distorted, and unentered. (IE, think of getting a piece of a map and then finding where...
forums.anandtech.com
sdifox
No Lifer
- Sep 30, 2005
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Why is ChatGPT posting here? I guess it is not smart enough to know this place is dead.
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I will be adding some mechanics videos over time, great for robotics :
This video explains by some examples how mechanical constructions can be build in such a way that mathematical functions can be emulated.
That might come in handy to reduce power consumption for example.
Very complex ball joint, the way the gears are used is amazing.
This video explains by some examples how mechanical constructions can be build in such a way that mathematical functions can be emulated.
That might come in handy to reduce power consumption for example.
Very complex ball joint, the way the gears are used is amazing.
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Almost forgot to add the site with basic explanation about how to use electronic components for to build robots. And how sensors basically work. motor drivers and motors AKA actuators. And more...
Great for the enthusiastic beginner. It looks incredibly complex when your not familiar with the knowledge.
But when you got your : "Eureka !" moment... You will be constantly mentioning : "Ohhh, is that all there is too it..."
Great for the enthusiastic beginner. It looks incredibly complex when your not familiar with the knowledge.
But when you got your : "Eureka !" moment... You will be constantly mentioning : "Ohhh, is that all there is too it..."
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This is a bit off topic, but fun to see how important it is to be creative when it comes to robots, if that may be in real life or movies.
This is definitely not a robot i would want to see build, the Cain cyborg from the movie Robocop 2 from the year 1990.
I always loved this movie. And although the Cain cyborg is the antagonist from our hero robocop, the Cain cyborg always remained very impressive to see in action.
What is interesting here, is that although the robot is actually a stop motion puppet : There are no actuators. But what is interesting, that all the parts are machine milled and hand milled.
And also the other props to create the fearsome actions of this creepy cyborg are all machine milled and hand milled.
Could come in handy for the inspiration.
This is a short video interview with Phill Tippett, one of the great masters when it comes to special effects in movies.
This is definitely not a robot i would want to see build, the Cain cyborg from the movie Robocop 2 from the year 1990.
I always loved this movie. And although the Cain cyborg is the antagonist from our hero robocop, the Cain cyborg always remained very impressive to see in action.
What is interesting here, is that although the robot is actually a stop motion puppet : There are no actuators. But what is interesting, that all the parts are machine milled and hand milled.
And also the other props to create the fearsome actions of this creepy cyborg are all machine milled and hand milled.
Could come in handy for the inspiration.
This is a short video interview with Phill Tippett, one of the great masters when it comes to special effects in movies.
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How To Mechatronics:
With as example video : A nice CNC machined cycloidal drive and how it works very much into detail :
With as example video : A nice CNC machined cycloidal drive and how it works very much into detail :
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3D printed cycloidal drive as example for robot arms , a rotary joint like for example as a sort of elbow or knee :
And how to make your own custom wooden enclosures :
And how to make your own custom wooden enclosures :
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Levi Janssen howto cycloidal drive with standard NEMA 23 steppermotor :
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Freecad is free to use to design your own mechanical parts and devices.
www.freecad.org
FreeCAD: Your own 3D parametric modeler
FreeCAD, the open source 3D parametric modeler
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LTSpice is a free and powerful spice simulator intended to be used for simulating electronic circuits.
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Würth Elektronik has great reference books one can learn a great deal from like for example a book : How to use LTspice simulator.
But also books on subjects like for example inductors , capacitors (Think electrical behavior, physics and more). Did you know that most ceramic capacitors, especially the large value ones exhibit microphone like behavior ? That means that if you tap on the capacitor and use it in a very impedance circuit, you can see voltage changes happening with a properly setup oscilloscope.
And what does the saturation current mean of an inductor and the rated rms current of an inductor ? You can find it in these reference books that are for sale.
You never want to go over the saturation current of an inductor because doing so will lower the inductance, because you are then saturating the core of the inductor when crossing the saturation current level.
This can be the cause of great influence on your circuit AKA , it stops functioning properly. Think of a buck converter, a stepdown converter.
When the current through the inductor is higher than the saturated current, your smps might become unstable, have increased ripple output voltage and even your power supply may start to oscillate, shut down or produce a too high voltage.
If you understand how switch mode power supplies function with inductors, it is easier to understand how electric motors work like a brushed dc motor , a brushless dc motor and a steppermotor. Because these motors also have inductors and the behavior is in essence the same.
And also remember how transformers work, and inductors, when you store energy in the inductor (in discontinuous mode) or the transformer, you must also take it out again.
Because if you do not, you will not reach the specifications of the motor and your motor drive may start to hate you so much and it burns up because you saturate the coils. That is where fast decay and slow decay modes and mixed decay modes are for...
To a limited degree you can also ask for samples as a company or university or school.
www.we-online.com
But also books on subjects like for example inductors , capacitors (Think electrical behavior, physics and more). Did you know that most ceramic capacitors, especially the large value ones exhibit microphone like behavior ? That means that if you tap on the capacitor and use it in a very impedance circuit, you can see voltage changes happening with a properly setup oscilloscope.
And what does the saturation current mean of an inductor and the rated rms current of an inductor ? You can find it in these reference books that are for sale.
You never want to go over the saturation current of an inductor because doing so will lower the inductance, because you are then saturating the core of the inductor when crossing the saturation current level.
This can be the cause of great influence on your circuit AKA , it stops functioning properly. Think of a buck converter, a stepdown converter.
When the current through the inductor is higher than the saturated current, your smps might become unstable, have increased ripple output voltage and even your power supply may start to oscillate, shut down or produce a too high voltage.
If you understand how switch mode power supplies function with inductors, it is easier to understand how electric motors work like a brushed dc motor , a brushless dc motor and a steppermotor. Because these motors also have inductors and the behavior is in essence the same.
And also remember how transformers work, and inductors, when you store energy in the inductor (in discontinuous mode) or the transformer, you must also take it out again.
Because if you do not, you will not reach the specifications of the motor and your motor drive may start to hate you so much and it burns up because you saturate the coils. That is where fast decay and slow decay modes and mixed decay modes are for...
To a limited degree you can also ask for samples as a company or university or school.
Reference Guides from Würth Elektronik
Our reference guides for you | Trilogy of inductive components and connectors | Abc of capacitors and power modules | Simulation LTspice IV
www.we-online.com
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I am doing this from memory so bear with me...
For some good explanation why motor drivers use fast decay mode and slow decay mode and mixed decay mode see these great application notes from ST to explain about steppermotors and from texas instruments to explain about dc brushed motors.
As written in post #49, the user of a steppermotor really wants the energy stored in the coil /inductor during a step, and still present in te coil / inductor to be removed. This energy present itself as current still stored as magnetic field and creating backEMF and you want to drain the magnetic field by draining the current. That is where the decay modes are for.
Why drain the current ? often, you have to reverse polarity for the next step and when there is still current flowing in the wrong direction , you will not be able to drain the current during the step.
The current you expected to flow will not flow and therefore the magnetic field strength you hoped to generate does not appear and you will not be able to generate proper torque or speed.
So, take that current out soldier !
In essence you short circuit the coil (which is just an inductor) for a moment or you apply the opposite voltage for a very short moment.
This puts quite a load on your much needed electrolytic low impedance buffer capacitors. So you have to make sure that you take the the maximum ripple current into account and do not forget about it or your electrolytic low impedance buffer capacitors will turn into POP ! corn.
And these electrolytic low impedance buffer capacitors are also great to absorb and level any load dump alike situations when properly chosen.
When you have chosen your electrolytic low impedance buffer capacitors correctly, you can also put a few in parallel but you have to take the pcb traces into account because of the inductance of the copper traces, therefore , make a low impedance and low inductance copper plane.
The fun part with a copper plane is that when you have a ground plane and above it a powerplane, that you get free capacitance also for high frequencies, not ideal but better than inductance.
In practice you always get what is called parasitic capacitance and parasitic inductance and of course normal resistance which for you as designer may also act parasitic.
Parasitic capacitance and parasitic inductance are in the pF, range respectively the nH range and together this can act as resonance tanks and oscillate at very high frequency.
For a example what can happen if you do not take this into account : Which may be a cause why the circuit is emitting EMI at a too high level to pass any EMC and EMI certification.
But that is where good pcb design comes in and at the right places EMI ferrite beads and ceramic capacitors ideal to be relatively low impedance for very high frequencies in the MHz range up to the GHz range.
This document, see page 16 :
With a dc brushed motor it is in essence the same. But you are using PWM here and you want to take out the current which is momentarily stored as a magnetic field that will present itself and the back EMF before the next pwm pulse.
In essence you short circuit the motor for a moment or you apply the opposite voltage for a very short moment.
Why do this all ?
Well, most of the time you do not have to do this, the logic inside the Hbridge dc brushed motor driver or the steppermotor driver takes care of this all. But you must be able to understand why it does do fast decay or slow decay. So you end up with a strong and speedy motor.
With steppermotors there is of course the hold current which is often a fraction of the rated current during stepping.
When you hold a steppermotor in a position , in essence the coil/inductor becomes together with an intelligent steppermotor driver, a sort of SMPS (switch mode power supply) that regulates on the hold current through the coil/inductor from the steppermotor. The holdcurrent looks on an oscilloscope, like a current which you can see as a DC current but with an AC triangle current placed on top of it. That triangle shaped current is the result of the current regulation of the steppermotor driver.
With dc brushless motors, this is the same. These motors have 3 phases, but the idea is similar like a steppermotor.
I know some theory but to be honest, i never had the chance to work with brushless motors yet. So no practical experience but as mentioned above, similar to steppermotors but different amount of phases, different amount of poles, a bit different construction and some more differences.
For some good explanation why motor drivers use fast decay mode and slow decay mode and mixed decay mode see these great application notes from ST to explain about steppermotors and from texas instruments to explain about dc brushed motors.
As written in post #49, the user of a steppermotor really wants the energy stored in the coil /inductor during a step, and still present in te coil / inductor to be removed. This energy present itself as current still stored as magnetic field and creating backEMF and you want to drain the magnetic field by draining the current. That is where the decay modes are for.
Why drain the current ? often, you have to reverse polarity for the next step and when there is still current flowing in the wrong direction , you will not be able to drain the current during the step.
The current you expected to flow will not flow and therefore the magnetic field strength you hoped to generate does not appear and you will not be able to generate proper torque or speed.
So, take that current out soldier !
In essence you short circuit the coil (which is just an inductor) for a moment or you apply the opposite voltage for a very short moment.
This puts quite a load on your much needed electrolytic low impedance buffer capacitors. So you have to make sure that you take the the maximum ripple current into account and do not forget about it or your electrolytic low impedance buffer capacitors will turn into POP ! corn.
And these electrolytic low impedance buffer capacitors are also great to absorb and level any load dump alike situations when properly chosen.
When you have chosen your electrolytic low impedance buffer capacitors correctly, you can also put a few in parallel but you have to take the pcb traces into account because of the inductance of the copper traces, therefore , make a low impedance and low inductance copper plane.
The fun part with a copper plane is that when you have a ground plane and above it a powerplane, that you get free capacitance also for high frequencies, not ideal but better than inductance.
In practice you always get what is called parasitic capacitance and parasitic inductance and of course normal resistance which for you as designer may also act parasitic.
Parasitic capacitance and parasitic inductance are in the pF, range respectively the nH range and together this can act as resonance tanks and oscillate at very high frequency.
For a example what can happen if you do not take this into account : Which may be a cause why the circuit is emitting EMI at a too high level to pass any EMC and EMI certification.
But that is where good pcb design comes in and at the right places EMI ferrite beads and ceramic capacitors ideal to be relatively low impedance for very high frequencies in the MHz range up to the GHz range.
This document, see page 16 :
With a dc brushed motor it is in essence the same. But you are using PWM here and you want to take out the current which is momentarily stored as a magnetic field that will present itself and the back EMF before the next pwm pulse.
In essence you short circuit the motor for a moment or you apply the opposite voltage for a very short moment.
Why do this all ?
Well, most of the time you do not have to do this, the logic inside the Hbridge dc brushed motor driver or the steppermotor driver takes care of this all. But you must be able to understand why it does do fast decay or slow decay. So you end up with a strong and speedy motor.
With steppermotors there is of course the hold current which is often a fraction of the rated current during stepping.
When you hold a steppermotor in a position , in essence the coil/inductor becomes together with an intelligent steppermotor driver, a sort of SMPS (switch mode power supply) that regulates on the hold current through the coil/inductor from the steppermotor. The holdcurrent looks on an oscilloscope, like a current which you can see as a DC current but with an AC triangle current placed on top of it. That triangle shaped current is the result of the current regulation of the steppermotor driver.
With dc brushless motors, this is the same. These motors have 3 phases, but the idea is similar like a steppermotor.
I know some theory but to be honest, i never had the chance to work with brushless motors yet. So no practical experience but as mentioned above, similar to steppermotors but different amount of phases, different amount of poles, a bit different construction and some more differences.
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