Spring 2017 BiPed – Servo Ankle Stress Experiment
By: Abraham Falcon (Electronics and Control)
Approved by: Alexander Clavel (Project Manager)
Table of Contents
Introduction:
Electronics and Control engineer job is to do an experiment on the servo motor to see if it can the handle the weight needed to perform the funtion of turning at the ankle. The following experiment is to know if the chosen servo motor can handle the Biped’s weight. The stress weight of the Biped was chosen to be at 500 grams as to be the maximum weight, but our actual weight should be lower than this. The experiment is also to see if the power consumption of the servo will exceed our maximum of 500 mA.
Experiment:
Table of results:
| Servo Motor | Servo Location | Stress Weight | Operating Voltage (Volts) | Stress Current
(Amps) |
| HXT900 Micro Servo | Ankles | 500 grams | 3.3 volts | 270 mA |
This experiment was done by hooking up the servo motor to the arduino and the digital multimeter in series. The weight of 500 grams was attached to a servo plastic gear with a radius of 1cm.
Here is an example of the servo connection without the weight and you can see that with no load the servo runs at the highest 71.961 ma.
The setup from above picture was used but added the weight of 500 grams. To simulate the weight of the ankle from Biped weight the servo was put upside down and observed if the full rotation of the gear on the servo with the weight performs well. By observing the weight on this servo, it can handle the stress weight of the biped and the current was around 270 mA.
Conclusion:
The experiment was preformed and showed that this HXT900 Micro Servo will make Biped be able to turn on the ankles and the current shows that the power consumption is under 500 mA. This experiment concluded that this servo will be effective for the ankles to turn. In the references section shows a video of the servo torque test of this type of servo chosen and this was a guide to perform this experiment.