Researchers from WSU presented a robot that can fly in all directions

A Washington State University (WSU) press release states that the developed prototype of the Bee++ robotic bee is the first robot that can stably fly in all directions. Bee++ has four carbon fiber and mylar wings, as well as four lightweight actuators to control each wing.

The study was conducted under the supervision of Nestor O. Perez-Arancibia, Associate Professor of the Department of Mechanics and Materials Science at WSU, the work is published in the IEEE Transactions on Robotics journal. Perez-Arancibia will present the results at the IEEE International Conference on Robotics and Automation later this month.

Researchers have been trying to create artificial flying insects for more than 30 years, Perez-Arancibia says. One day they can be used for many purposes, including artificial pollination, search and rescue in cramped conditions, biological research or environmental monitoring, including in adverse conditions. But in order to make tiny robots take off and land, it took the development of controllers that act in the same way as the insect brain.

Initially, the researchers developed a two-winged robotic bee, but it was limited in its movements. In 2019, Perez-Arancibia and two of his graduate students created for the first time a four-winged robot light enough to take off. Scientists have provided the ability to perform two maneuvers, tilt and rotation. In the first case, the front wings wave differently from the rear, and in the second, the right wings wave differently from the left, creating torque. But being able to control the complex yaw movement is extremely important, he said. Without this, robots get out of control, they can't focus on a point. As a result, they are broken.

"If you can't control the yaw, you're very limited," Perez-Arancibia says. "If you're a bee, here's a flower, but if you can't control the yaw, you're spinning all the time trying to get to it."

Having all degrees of mobility is also critical for evasive maneuvers or tracking objects.

"The system is very unstable and the problem is very complex," he said. "For many years, people had theoretical ideas about how to manage the yaw, but no one could achieve this because of management constraints."

In order for the robot to turn in a controlled manner, the researchers took an example from insects and moved the wings so that they flapped at an angle. They also increased the number of times per second when the robot can flap its wings - from 100 to 160 times per second.

"Part of the solution was the physical design of the robot, and we also came up with a new design of the controller - the brain that tells the robot what to do," he said.

With a weight of 95 mg and a wingspan of 33 mm, Bee++ is still larger than real bees, which weigh about 10 mg. In the current iteration, the robot can fly autonomously for about five minutes on a single charge, so basically it is tied to a power source via a cable.