Rotation angle measurement of pedal with ball and socket joint

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Discussion Overview

The discussion revolves around measuring the rotation angle of a pedal connected to a ball and socket joint, specifically in the context of an experiment involving a sedated cat. Participants explore various methods and devices for achieving high precision in angle measurement, considering the specific requirements and constraints of the setup.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • Some participants suggest marking graduations on the ball joint for angle measurement, while others express skepticism about the precision of this method.
  • A proposal is made to use a structure involving three rods and rings to determine the angular position of the pedal, but the need for high precision (0.25 degrees) raises concerns about this approach.
  • Questions are raised about the specific application of the pedal, including its operational environment and the nature of the angles to be measured (azimuth, elevation, and rotation).
  • One participant suggests using a laser beam reflected off a mirror attached to the pedal to measure angles, but this is challenged due to the pedal being operated by a foot.
  • Another participant references the use of coordinate measurement machines (CMM) and their methods for measuring angles and positions, noting the complexity and size of such devices.
  • There are discussions about the feasibility of smaller CMM devices for the specific application involving a small animal.
  • Links to various measurement devices and suppliers are shared, with some participants expressing interest in budget considerations for acquiring suitable equipment.

Areas of Agreement / Disagreement

Participants express a range of ideas and methods for measuring the angles, with no clear consensus on the best approach. There are competing views on the practicality and precision of suggested methods, and the discussion remains unresolved regarding the optimal solution.

Contextual Notes

Participants highlight limitations related to the size and complexity of measurement devices, as well as the need for high precision in the specific experimental context. The discussion also reflects uncertainty about the effectiveness of various proposed methods.

Who May Find This Useful

Researchers and practitioners involved in experimental design, particularly those focused on precision measurement in biological or mechanical contexts, may find this discussion relevant.

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  • #32
Hello guys,

I found three inclinometer sensors with the resolution and accuracy required.
the only problem is the weight, which I think can be solved if using the chip without the housing,

I wonder if you have come across these sensors so I can get your feedback.

https://www.gsglobalresources.com/products/control...

Thanks,
 
  • #33
3-axis accelerometers are used in a range of things from aircraft navigation equipment to cell phones.

Sensitivity is often shown as resolution in mG where your ±0.25° translates to 4.4mG, where G is the acceleration of Gravity at the Earths surface.

Here is a link to one source of low cost ones. The drawback is they are just the packaged sensor itself, you have to supply all the electronics to use them. Prices range from USD $1.32 to $178.55 at this distributor, there are others.
https://www.mouser.com/Sensors/Motion-Position-Sensors/Accelerometers/_/N-axgd7?P=1ynyo5tZ1y9irx0Z1ykfg8jZ1yu25cjZ1y9k2dtZ1y9gw93Z1y96oa1Z1yoi99nZ1y8pyzaZ1yyfbu4Z1yoi9b7Z1yq2rrdZ1yq2rrbZ1yzuq36Z1yvt0viZ1yzv7ytZ1yyg66sZ1y9geabZ1yrhbd5Z1yzvsot

(above found with:
https://www.google.com/search?&q=tri+axis+accelerometer+sensor)

Cheers,
Tom
 

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