Educational Example on Optimum Cool Refrigerating Capacity Adjustment for Fridges and Freezers by Fill Level Indication using Series of Pressure Measurements

Education in mechatronics can be focused on in various ways. One primarily important way in first place are basic (often theoretical) lectures. Once the basics have been settled among the students, one could advance the difficulty level on follow up lectures to deepen the knowledge - or focus on the hands-on implementation of real mechatronic problems using easy to setup powerful hardware. The latter is the methodology we focus on using Bosch's XDK supporting various communication standards and having multiple sensors on board. In this paper we investigate some specific sense-able facts of customer's user behavior towards smart fridges and freezers. White goods become smarter every day providing improved convenience for the consumer. In our context, we focus on the estimation of the current fill level of a freezer or fridge to both drive the device in an energy efficient way and also to quickly adopt the cooling power when additional goods to be cooled are added to the device's content. Our measurement approach focuses on the evaluation of differing internal air compression profiles when closing the device's door depending on the actual fill level. The profiles allow conclusions on the percentage of free floating air versus solid goods inside the device, allowing to derive efficient and effective cooling profiles. The presentation of the approach and the results represent a comprehensive example of hands-on mechatronics education.