'In Medio Stat Virtus'
Making Of


Placeholder image

Here I want to share the build details for the kinetic installation 'In Medio Stat Virtus', which is a machine that tries to find a balanced state, using a machine learning algorithm.

-> To the Project Description

Hardware:
Arduino(for prototyping)
2 x luggage scales
2 x HX711 modules
2 x stepper motors

Software:
Arduino (Q-Behave, Accelstepper library)

In order to let the machine learn about how to find the balance, it was a sensor required that can measure the weight in a hanging position. The weight sensor should have been very small and send accurate data to a microcontroller. I could not find a load cell that was fitting my aesthetical and technical requirements. In the end I extracted the inner of a standard luggage scale.

Placeholder image
Placeholder image
With an HX711 ADC module the analog data gets transformed into readable data for the Serial Port of the Arduino.

Placeholder image
I connected the extracted load cell to the module and to the Arduino. Here I followed the wiring diagram of the HX711 ADC module. Using the HX711 Library I calibrated the sensor with a known weight. Then I produced my second weight sensor to have two comparable weights for the algorithm.

Placeholder image

Placeholder image

Let it balance:

The weight sensors are attached on strings. The actual physical balancing by pulling and loosening the cords is done by stepper motors. Their actions are random at first, while the weights of the two sensors are constantly read.

As soon as the difference in the measured weights decreases, the system receives a reward. The machine tries to become better. This is how the machine approaches a balanced state. The machine learning algorithm is based on the Q-Behave library for arduino.

In the end the Arduino was replaced with my own board based on the ATM Mega328P-PU chip the Arduino uses.

The schematic:

Placeholder image

The Final Construction:

Placeholder image
Placeholder image

Placeholder image
-> To the Project Description