Hi
I am working on a project of robotic knee and mechanical design is almost in the final stages.
However, i am facing an issue in finalizing mechanism for measuring knee angle in real time.
Due to design constraints i cannot place sensor directly on axis of rotation of knee joint.
Any help in identifying sensor type along with mounting mechanism will be high appreciated.
The sensor does not have to be mounted on the axis of rotation, in order to measure the rotation angle.
jremington:
The sensor does not have to be mounted on the axis of rotation, in order to measure the rotation angle.
Where should i mount the sensor than? and which sensor should be used?
If you use an orientation sensor, like an accelerometer, mount it anywhere that makes sense to you. It will tell you the direction of "down" (defined by gravity) with respect to the sensor mounting position and orientation.
If you take a few moments to post and explain a diagram of the machine, and all the angles that are relevant to the problem, you will get better answers.
Thank you for the suggestions. Attached is the model of prosthetic knee. I am designing something similar to that. I am interested in measuring knee flexion and extension angle precisely.
jremington:
OP's image, posted properly:
Definition of "knee flexion angle", from this publication
Thank you for correcting me.
Yes this is exactly what i am interested in measuring.
It is very popular to measure that angle, therefore there are a number of techniques, all described on the web, with pictures.
Use your favorite search engine with the phrase "measure knee flexion angle" to find them.
jremington:
It is very popular to measure that angle, therefore there are a number of techniques, all described on the web, with pictures.Use your favorite search engine with the phrase "measure knee flexion angle" to find them.
These techniques are generally used to find knee flexion angle of healthy human leg in clinics. However, i am interested in using a sensing scheme in robotic/prosthetic knee joint.
I have searched keyword you suggested, but i could not come up with a solution that i an work on implementation.
You could fit a bell crank in the joint and “transmit” the movement to a pot/ encoder mounted somewhere else.
hammy:
You could fit a bell crank in the joint and “transmit” the movement to a pot/ encoder mounted somewhere else.
Thank you from your answer i found an alternate way of doing it.
