5
votes
Accepted
How can a coaxial stepper motor be used to drive the Z axis effector of a SCARA robot?
i found out that it is called an RZ tool ... google scara RZ tool
there is a captive rotating "nut" on the threaded shaft that causes the shaft to move linearly
...
- 518
5
votes
Accepted
Why do series elastic actuators have more accurate and stable force control?
Series elastic actuators tend to have more stable force control because the spring filters out the high-frequency motion of the mechanism. A low frequency in the system dynamics means that you can use ...
- 4,385
4
votes
Accepted
What types of actuators do these industrial bots use?
Actuation is a complex subject that cannot be reduces to 1 component alone. It is the interaction of software electronics and mechanics. "Toy" servos tend to incorporate everything in one small ...
- 6,652
4
votes
Accepted
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
...
- 4,525
4
votes
What servos are suitable for a robot like Boston Dynamics’ Atlas?
The Boston Dynamics’ Atlas robot doesn't actually use servo motors. It uses electrically-powered hydraulic actuation.
I saw a presentation by Boston Dynamics' Marc Raibert where (if I remember ...
- 1,054
3
votes
Accepted
What is an "actuation state"
after reading this ... there are mentions of task-space, state-space, configuration-space, etc
https://www.researchgate.net/publication/...
- 518
3
votes
What types of actuators do these industrial bots use?
A robot like the one you refer to probably has a mix of transmission types that increase in power-to-weight ratio and decrease in size and stiffness as you move outwards on the kinematic chain. The ...
- 106
3
votes
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Linear actuators in a cartesian robots
I have worked on a cartesian robot with similar requirements† as your own, and we selected direct drive synchronous linear motors for our x/y stages. In our case, both axes were around 2m in ...
- 4,243
3
votes
Accepted
Does MIT Cheetah uses Series Elastic Actuator?
It seems that the answer is that it doesn't actually use either of those designs.
According to the paper Proprioceptive Actuator Design in the MIT Cheetah: Impact Mitigation and High-Bandwidth ...
- 1,054
3
votes
Accepted
What is the typical intro example for control systems for a spherical joint?
The best example I can think of would be the spherical pendulum. Albeit, this is not exactly the easiest thing to regulate as you have two degrees of freedom and a frictionless contact (well depending ...
- 543
3
votes
What are the pros and cons of Zip Chain Actuators in robotics?
The primary feature of a zip chain actuator is that it does not need extra depth to retract into. A standard linear actuator has a slider that will travel back behind the point of actuation. It will ...
- 24.7k
3
votes
Accepted
Is it worth designing your own components to mount a ball screw?
The general answer I would give anyone, working on any project, who asked this question:
Should I buy commercially available, off-the-shelf (COTS) parts, or make my own?
would be to always buy off-...
- 16k
2
votes
Can't Read current on Pololu Dual MC33926 Motor Driver Shield for Arduino
I know this thread is old but it's high on Google results and I would like to clarify for anyone who stumbles upon it in the future an answer not yet listed: this chip is not designed to read current ...
- 31
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 ...
2
votes
How can I turn a bowl/glass upside down?
Here's an idea
Explanation
Instead of the servo bearing the weight, there is an axis through the bowl that the servo is attached to. This takes all of the strain off of the servo. The servo arm is ...
- 41
2
votes
How to get started on making a dispenser for Indian spices?
You should have a look at small screw conveyors. Either experimentally find out how much you have to turn for your spices or make a feedback loop with a scale.
- 1,355
2
votes
Which motors are used in boston spot robot
I had the chance to play with Spot this afternoon and it is not hydraulic.
I bet for a stepper motor with cycloidal gears and position encoders. But I not really sure which kind of motor. They didn't ...
- 121
2
votes
Control method of large linear actuator
The LAS3 actuator draws a current of 2.5 Amps @ 24Volts and has a DC motor, so the H-Bridge in the link can be used to control it. It is even a bit overdimensioned. You can link the Ardunio to the H ...
- 6,652
2
votes
Accepted
State of the art trajectory for fine precision robots
For very high-precision applications such as finishing, milling by CNC machines, jerk-bounded trajectories (that is, trajectories comprising polynomials of degree 3 of higher) are often used. If you ...
- 1,829
2
votes
Design a robot that can apply hot glue to paper
The problem I see is that after a while of holding the trigger, you have to let go of the trigger and then squeeze again. This is because the trigger has advanced the stick of glue as far as the ...
- 207
2
votes
Controlling Actuated Robot Hand in Underactuated Manner
I don’t think underactuated is the proper term. You are trying to control multiple actuators with a single DOF. That is redundancy resolution. I have used the Simplex Method to compute stable ...
- 4,386
2
votes
Accepted
Output power of an actuator - General definition
It reads to me like the author is stating that a stiffer material means it could make an actuator with more output power, which doesn't make a lot of sense to me.
Maybe they mean a more efficient ...
- 16k
2
votes
Accepted
Why Hydraulics and Not Motors?
Hydraulics and pneumatics let you separate the mechanical power generation component (compressor, hydraulic power unit, etc.) from the actuator. In the case of something like a robotic arm, this means ...
- 16k
2
votes
What type of actuators are needed for a high accuracy, low load weight robotic arm?
Ask yourself if you really need accuracy or precision. Because I think precision is easier to achieve than accuracy for most arms.
I am not sure I would be as worried about the actuator as the gear-...
Ben♦
- 5,825
2
votes
Accepted
Controlling motion of single link
I believe all of the above is correct, but if someone thinks otherwise I would welcome the correction.
Yes, it's correct.
The boundary conditions now include (I think) $\ddot{\theta} = 0$ at $t=0$ ...
- 1,369
1
vote
Accepted
Rotary Serial Elastic Actuator
For an arm with series elastic actuators I'm not aware of an open source design. There are many mechanisms you can find in research papers if you search for them.
For force control you have a few ...
- 4,385
1
vote
Rotary Serial Elastic Actuator
There was a paper describing a rotary series elastic actuator for human-assistive systems in IEEE/ASME Transactions on Mechatronics, Vol. 17, No. 2 (April 2012).
The paper included diagrams of the ...
- 1,054
1
vote
Replace screws with motors!
You are best off using the servo's horn/hub (the plastic or metal disk or arm that you attach to the servo), and screwing the arm to the hub. You get buy some larger horns for fairly cheap, and that ...
- 266
1
vote
Electronic Spring Vibrating Spheres
The term for the electrical component that actuated (vibrates) at a selectable frequency is "Piezoelectric actuator". You can also examine vibration motors, like in the mobile phones or in the ...
- 411
1
vote
Are scissors what I want for moving straight up and out?
a robot that could get items out of the dishwasher and put them away
This is an active research topic. Toyota has a whole division working on assistive robotics, close to Stanford in Palo Alto. It is ...
- 720
Only top scored, non community-wiki answers of a minimum length are eligible