Battery Management for Transport Robots

How can we optimize the battery management of transport robots? Stefan deals with this important issue at InSystems Automation. Born and raised in Wilhelmshaven, he should develop methods to improve charging technology and battery duration. According to his schedule in the next months, Stefan will above all test many batteries extensively. The proANT transport robots are equipped with dry batteries based on lithium-iron-phosphate, the same which are installed also in e-bikes, mobile phones or notebooks.

The battery management for transport robots

Stefan’s workplace is located in the workshop. There he already built a small test site, where he tests the charging and discharging behavior of battery cells with different configurations and stores the measurement data. His task consists of testing and optimizing the current battery management of the autonomous navigating proANT transport robots. InSystems uses for its vehicles lithium ions secondary batteries, so called dry batteries based on lithium-iron phosphate LiFeYPo4. The single cells are connected into blocks with the necessary capacities by a balancer board.

For the battery duration it is important, that all cells have the same voltage when the connection occurs. The balancer board ensures during operations that all cells are charged steadily. However, it happens every now and then, that some single cells in block are faulty. The reason cannot be detected yet, but probably the failure is caused by a production error of the supplier. With the battery test site all incoming batteries should be submitted to the test, whose data are recorded, in order to detect abnormalities in the battery cells right away or for later claims.

The cells of these batteries are capable of handling high currents, resistant to cycling and barely self-discharging. Furthermore they have no memory effect, so that the cells have a very long lifetime of about five years if properly used. Stefan also says „Maybe we find a way to extend the usage period of the batteries. It would also be interesting to switch to new technologies like contactless charging.” ProANT transport robots have spring loaded contacts which docks on the charging station. If the vehicle is docked and confirms the contact, current flows. The charging process lasts usually 30 to 40 minutes. After charging, the vehicle is available for operations for 6 to 8 hours.

What did Stefan do before?

Stefan looks back on a challenging career so far: he is both a practical man and a theorist in one person. Originally Stefan is a qualified electrician, a profession he worked in for more than twenty years, and acquired additional skills during his positions. Most recently he worked as a research assistant in the field of decentral and autonomous energy and network technology for a Berlin based company and for the Federal association of solar mobility (BSM). Here he started small and bigger research projects and consolidated his knowledges exploring storage technology. As a result, he developed a concept for a net-friendly behavior of storage for the company Total.

How did you experience your first time at InSystems? What are your outlooks?

During his first days at InSystems, Stefan got at first an overview. He notices „ The workshop team is very cooperative and it is fun to participate.” What he likes most “InSystems has no fear of innovations and is open to experiments. At other companies I probably couldn’t have started right away with testing, instead I would have first filled tons of paper with the project goals.” For Stefan this means getting during the next weeks new insights for practice from his experiments on the test site, in order to implement soon some first strategies to improve the battery management.

 

Links:

http://www.proant.de/portfolio-fahrerlose-transportsysteme/batterietechnik/

Bundesverband Solare Mobilität