Marc Raibert

Overview

Marc Raibert was born on 22 December 1949 ^[1]. Trained as an electrical engineer and computer scientist, he is known for building robots that stay upright by moving rather than by resting on a wide, stable base, and for founding the company Boston Dynamics ^[1]. His work joins three things that are usually taught separately: control theory, biomechanics and mechanical design.

Education and early research

Raibert received a Bachelor of Science in electrical engineering from Northeastern University in 1973 and a PhD from MIT in 1977 ^[1]. His doctoral dissertation, *Motor Control and Learning by the State Space Model*, was advised by Berthold Horn and Whitman Richards ^[1]. A state-space model describes a system through a set of internal variables plus the rules that carry them from one moment to the next; applying that idea to motor control means treating posture and motion as quantities that can be estimated and corrected continuously, rather than as a fixed pose to be held.

The Leg Laboratory and legged locomotion

In 1980 Raibert founded the Leg Laboratory at Carnegie Mellon University, where he was an associate professor of computer science and robotics ^[1]. There he developed the first self-balancing hopping robots, a significant step forward in robotics ^[1]. A one-legged hopping machine shows why the problem is hard and interesting: it cannot simply stand still — it stays up only by pushing off the ground at the right instant and placing its foot in the right spot for the next landing. Balance therefore becomes a question of timing and foot placement rather than of static stability. In 1986 he published *Legged Robots that Balance*, setting out this approach in book form ^[1]. He later became professor of electrical engineering and computer science at MIT ^[1][2].

Boston Dynamics

Boston Dynamics dates its own founding to 1992, when Raibert spun off from the MIT Leg Lab to start the company; Robert Playter joined soon afterwards ^[2]. Raibert served as chief executive and later became chairman ^[1][2]. Ownership of the company changed hands several times: Google acquired it in December 2013, SoftBank in June 2017 and Hyundai Motor Group in 2020 ^[1]. The company thus began as a spin-off of a university laboratory working on a long-running research question rather than around an existing product.

Recognition and current work

In 2008 Raibert was elected a member of the US National Academy of Engineering, for biomechanically motivated analysis, synthesis, control and application of multi-legged robots ^[1]. He is a founding fellow of the Association for the Advancement of Artificial Intelligence ^[1]. He is executive director of the Boston Dynamics AI Institute, an organisation of the Hyundai Motor Group ^[1].

The thread that runs through it

The same question runs through all of this work: how does a machine with legs hold its balance while it is moving? Raibert pursued it first in a university laboratory, then in a company spun out of that laboratory, and now at an institute belonging to the group that owns the company ^[1][2]. The hopping robots built in 1980 and the later work differ in scale and hardware, but they start from one premise: stability is not a pose the machine arranges itself into, but something it produces on the ground beneath it, moment by moment.