UNNC team achieves breakthrough in drone motor technology

11 January 2021

A high-tech startup co-established by Bowen Shi, an alumnus of University of Nottingham Ningbo China (UNNC), has successfully developed high-speed, sensor less FOC technology for drone propulsion system, which has already received an order from an Israel drone manufacturer.

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This technology innovation is mainly used for tethered drones. Tethered drones are physically connected to a ground power station via cable, where low weight and high endurance are required. However, how to minimise its size and adapting high voltage working condition has been a technological challenge.

Bowen introduced that the Sensorless HS FOC technology can achieve higher control frequencies, precision, stability and high-speed dynamic responses. However, it has a high technical threshold and requires complex mathematical algorithms.

The complexity of the project and its numerous failures almost made the team believe it “implausible in principle”. But their unremitting efforts paid off. The team developed a tethered drone motor, with its ESC (electrical speed controller), of only 50 grams but with a speed up to 30,000 rpm and output power of 1,000W. The frequency difference is 5-10 times higher than the current technology.

The technological success soon revealed its commercial possibilities when a leading drone production company in Israel placed an order. " I am proud to say that at present, we have no competitor for this kind of product around the world. And therefore, we are favoured by the top companies in the industry," says Bowen.

After completing undergraduate study at UNNC, Bowen headed for doctoral education and became a PhD student of Professor He Zhang, a principal research fellow of UNNC. "Professor Zhang always said that research should not be limited to the laboratory. It should withstand massive repeatable tests, be verified in actual scenarios and finally be applied." This deeply influenced Bowen.

Being optimistic about the industry, Bowen and his team first decided to utilise their technical advantages to optimise electronic drive systems for drones but were quite frustrated by the industry barriers. The UNNC Li Dak Sum incubator – where the startup was based - then contacted entrepreneurship advisor, Dr Lin Huang from the Faculty of Business, for advice.

She pointed out that a startup which has less influence and market share than big companies, the goal of “being better than the current” is not competitive enough, and only unique products gain attention. Following the advice, Bowen and his team avoided the mature fields and discovered their own direction in the application of FOC technology. In 2019, the team obtained funding of 700 thousand RMB from the Incubator.

This year, Bowen plans to achieve large-scale production of the ultra-small tethered drone electromechanical drive system. "I hope to develop meaningful engineering via technological innovation."