Hello all potential Arduino experts.
Short introduction: My name is Lasse Jakobsen. I am a PhD student at DTU (Technical University of Denmark) and my research is related to tribology (friction and wear) of footwear, with the aim of reducing the occurrence of slip injuries and some sports injuries.
We have created a portable mechanical test device, which is intended to be operated in the “field” (work environments and sports arenas). However, I am no expert in motor controlling, but I have been told, that an Arduino may do the job.
I would very much appreciate some guidance regarding the choice of hardware components and potential setup solutions. Specifically in relation to force measurement and regulation of motor velocity.
I have attached a few illustrations of the setup and hope that it makes sense.
A 18 v drilling machine is used as a rotating motor, with a rubber-covered disc mounted in the drilling head. The rubber-covered disc represents a shoe outsole and is in contact with the floor. The drilling machine is mounted in a cage with a universal joint, making it free to rotate vertical and horizontal. When the rotating disc meets the floor, the cage with the drilling machine will turn horizontally (left or right, dependent on the rotating direction of the drilling machine) and the cage with the drilling machine will touch a force sensor, mounted on a beam. The force sensor will provide a horizontal force (friction force) and should ideally be able to measure in the range of 1000-1500 N.
We need the motor in the drilling machine to rotate with a constant velocity, independent on the amount of applied load (weight plates), materials attached to the rotating disc or type of floor. Hence, if the motor rotates with 10 rpm before the disc comes in contact with the floor, it should regulate the current, thus the motor still rotates with 10 rpm when the rotating disc comes in contact the floor (when the resistance increases).
I would imagine that we need an encoder or tachometer to determine the rotating velocity of the disc, which will provide an input for the motor (through an Arduino) to regulate the current. However, I am not sure which kind of sensor (encoder or tachometer) will be suitable for this application?
Lastly, we need a force sensor, which ideally can log force data synchronal with rotating velocity and time.
I hope the above makes sense. Otherwise, I will be more than happy to elaborate or explain further to any kind person, who may be able to help us.