Reference designs add flight time to drones

Article By : Graham Prophet

TI’s 2S1P BMS reference design turns a drone’s battery into a smart diagnostic black box recorder to monitor remaining capacity and protect battery.

Enabling drones to fly longer, Texas Instruments’ two subsystem reference designs are designed to help manufacturers add flight time and extend battery life. These two reference designs target quadcopters and other non-military consumer and industrial drones used to deliver packages, provide surveillance or communicate and assist at long distances.

TI’s 2S1P Battery Management System (BMS) reference design transforms a drone’s battery pack into a smart diagnostic black box recorder that monitors remaining capacity and protects the Li-ion battery throughout its entire lifetime. Designers can use the drone BMS reference design to add gauging, protection, balancing and charging capabilities to any existing drone design and improve flight time. Using the bq4050 multi-cell Li-ion “gas gauge” (capacity meter) to measure remaining capacity over the entire life of the battery, the design also employs the bq24600 battery charge controller and a DC/DC converter to achieve high power conversion efficiency.

Another barrier to increased flight time has been the inefficiency of turning a drone’s propellers. A TI reference design for drone electronic speed controllers (ESCs) will help manufacturers create drones with longer flight times, and smoother and more stable performance. The sensorless high-speed field oriented control reference design for drone helps electronic speed controllers achieve the highest possible efficiency with speeds of more than 12,000rpm (>1.2kHz electrical) including fast-speed reversal capability for more stable roll movement.

The design features TI’s InstaSPIN-FOC C2000 system, including an F28027F microcontroller for precise motor control and FAST field observer proprietary software algorithm that estimates the rotor flux, angle, speed and torque. Motor parameter information is used to tune the current control bandwidth. Unlike other techniques, the FAST sensorless observer algorithm is self-tuning, requiring no adjustments for proper operation and propeller control. The design also includes a 60V LMR16006 simple switcher DC/DC converter with ultra-low quiescent current to efficiently manage a drone’s LiPo batteries.

“Flight time continues to be a top design challenge for recreational quadcopters and professional drones,” said Stelios Kotakis, senior analyst of data transmission and managed services at IHS Markit. According to a recent IHS Markit study, almost 50% of drones in the market have an estimated battery life of less than 30 minutes, 35% can fly between 31 and 60 minutes and the remaining 15% and less can fly more than an hour–all under ideal flying conditions without additional payload.

First published by EDN Europe.

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