How Many Actuators are Needed to Build a Robot?

Building robots with a minimal number of actuators is compelling. It allows for a reduction of cost, weight, as well as energy consumption. Besides, the robot needs to carry less battery. However, minimizing the number of actuators is not an easy task.

People from UC Berkeley Biomimetic Millisystems Lab have been investigating small legged robots for a while. They came up with a neat solution that requires only 1 single motor. The robot called 1STAR (1 actuator STeerAble Robot) is shown in Video 1 below, presented last June at the ICRA 2014 conference.

Minimizing the number of actuators has been investigated since a very long time ago in the realm of UAVs. In 2009, researchers form the Autonomous Vehicl Lab of the University of Maryland introduced the first monocopter: RoboSeed inspired from a maple seed (see Video 2). It uses a single motor and a servo. Our friends from The UAV Digest dedicated a full episode interviewing Dr. Evan Ulrich about this cute little flying robot.

At the ICRA 2014 conference, Piccoli and Yim from the MODLAB (Modular Robotics Lab) of the University of Pennsylvania went a step further. They have shown that it’s possible to make a flying robot capable of hovering with only one motor (see Video 3).

Video 1: The 1 actuator STeerAble Robot (1STAR)

Video 2: RoboSeed a Maple Seed Inspired UAV

Video 3: Single Motor Hovering UAV