A Robotic Bee That Can Fly Fully In All Directions Developed By Researchers

Researchers at Washington State University have successfully developed a robotic bee capable of flying in all directions. The innovative prototype, known as Bee++, features four carbon fiber and mylar wings, each equipped with lightweight actuators for precise control. This achievement marks the first time a robotic bee has demonstrated stable flight in all directions, including complex motions like yaw.

The Bee++ weighs 95 mg and boasts a 33-millimeter wingspan, making it larger than real bees, which weigh around 10 milligrams. However, the robot's autonomous flight time is limited to approximately five minutes, after which it must be tethered to a power source via a cable. The researchers are also working on developing other types of insect robots, including crawlers and water striders.

Led by Néstor O. Pérez-Arancibia, an associate professor in WSU's School of Mechanical and Materials Engineering, the team published their findings in the journal IEEE Transactions on Robotics. Pérez-Arancibia will present the results at the upcoming IEEE International Conference on Robotics and Automation.

For over three decades, researchers have been striving to create artificial flying insects. These miniature robots have the potential to revolutionize various fields, including artificial pollination, search and rescue operations in confined spaces, biological research, and environmental monitoring in hostile environments.

However, achieving liftoff and controlled landing for these tiny robots required the development of controllers that mimic the functionality of an insect's brain.

"It's a mixture of robotic design and control," explains Pérez-Arancibia. "Control involves highly mathematical principles, where you design an artificial brain. Some refer to it as hidden technology, but without these simplified brains, nothing would work."

Initially, the researchers developed a two-winged robotic bee, but its mobility was limited. In 2019, Pérez-Arancibia and two of his PhD students successfully constructed a four-winged robot light enough to achieve takeoff. To perform maneuvers like pitching or rolling, the researchers programmed the front and back wings, as well as the right and left wings, to flap differently, creating the necessary torque to rotate the robot along its main horizontal axes.

However, controlling the complex yaw motion proved to be crucial. Without it, the robots would lose control and be unable to focus on a specific target, resulting in crashes.

"If you can't control yaw, you're super limited," Pérez-Arancibia states. "Imagine a bee trying to reach a flower but constantly spinning due to the lack of yaw control."

Full freedom of movement is also essential for evasive maneuvers and tracking objects effectively.

"The system is highly unstable, and the problem is extremely challenging," Pérez-Arancibia explains. "For years, people had theoretical ideas about yaw control, but actuation limitations prevented successful implementation."

To address this issue, the researchers took inspiration from insects and adjusted the wing orientation to allow controlled twisting. They also increased the wing flapping frequency from 100 to 160 times per second.

"The solution involved both the physical design of the robot and the invention of a new controller—the 'brain' that guides the robot's actions," Pérez-Arancibia reveals.