Masaaki Kumagai

About

Masaaki Kumagai is a robotics researcher whose work has fundamentally advanced the field of dynamically balanced mobile robots, particularly through his pioneering development of ballbot systems — robots that balance and navigate on a single spherical wheel. His most celebrated contribution, "Development of a Robot Balancing on a Ball" (2008, 115 citations), introduced a compelling alternative to two-wheeled inverted pendulum platforms like the Segway, enabling omnidirectional movement without requiring orientation changes. This foundational work sparked a productive research trajectory that has shaped modern ballbot design worldwide. Kumagai's subsequent research tackled the key engineering challenges surrounding ball-driven locomotion, including sophisticated sensing systems using optical mouse sensors to track three-dimensional ball rotation (2011, 32 citations) and novel drive mechanisms for semi-omnidirectional motion. Perhaps most ambitiously, he led the development of the spherical induction motor (SIM), a landmark innovation that dramatically reduces mechanical complexity in mobile robots. His SIMbot prototype (2016) demonstrated a human-sized ballbot with just two active moving parts, representing a significant leap forward in elegant robotic actuation. Kumagai has also explored biped roller-skating locomotion and real-time Linux-based robot control, reflecting the broad scope of his contributions to practical, innovative robotics engineering.

Research Focus

Key Achievements

Top Papers

1. 1
   Development of a robot balancing on a ball

   115 citations · 2008
2. 2
   Six-stator spherical induction motor for balancing mobile robots

   35 citations · 2015
3. 3
   Development of a three-dimensional ball rotation sensing system using optical mouse sensors

   32 citations · 2011
4. 4
   Development of a Robot Balanced on a Ball - First Report, Implementation of the Robot and Basic Control -

   31 citations · 2010
5. 5
   Initial results for a ballbot driven with a spherical induction motor

   15 citations · 2016
6. 6
   Development of a ball drive unit using partially sliding rollers — An alternative mechanism for semi-omnidirectional motion —

   12 citations · 2010
7. 7
   Torque evaluation method of spherical motors using six-axis force/torque sensor

   10 citations · 2016
8. 8
   Development of a human type legged robot with roller skates

   6 citations · 2010
9. 9
   Wheel Locomotion of a Biped Robot Using Passive Rollers – Large Biped Robot Roller Walking Using a Variable-Curvature Truck –

   6 citations · 2008
10. 10
    Development of Robot Control System Using Common Linux.

    4 citations · 2002

Key Collaborators

Contact & Links