Yoichi Hori / Professor / Transdisciplinary Sciences Division
Department of Advanced Energy / / Control of electric vehicles, wireless power transfer system, application of supercapacitors, human-friendly motion control.

Career Summary
1978: B.Eng, Faculty of Engineering, The University of Tokyo
1983: D.Eng, The University of Tokyo
1983-1984: Research Associate, The University of Tokyo
1984-1988: Lecturer, The University of Tokyo
1988-1995: Associate Professor, The University of Tokyo
1995-2000: Associate Professor, Engineering Research Institute, The University of Tokyo
2000-2002: Professor, Department of Electrical Engineering, The University of Tokyo
2002-2008: Professor, Institute of Industrial Science, , The University of Tokyo
2008: present position

Educational Activities
Graduate school: Control and System Theory
Dept. of E.E.: Control Engineering I & II, Motion Control
Many omnibus-style lectures, mainly for the Dept. of Liberal Arts

Research Activities
Control of Electric Vehicles
Our objective is to utilize the quick response torque generation of electric motors to develop novel control techniques for electric vehicles (EVs). In 2011, we developed a vehicle stability control system for slippery roads, a GPS, and vision system-based vehicle state estimation methodologies. Moreover, by taking advantage of suspension structure, we made advances on pitch and roll motion control for EVs powered by an in-wheel motors (IWM). Our research generated plenty of high-quality papers and was also reported and highlighted in extensive media outlets. We developed the FPEV2-Kanon, an original EV equipped with four IWMs, a four-wheel steering system, and lateral tire force sensors, and a small EV, the C-COMS1, that is equipped with a GPS and a vision system. We are currently developing a new EV called the FPEV4-Sawyer that enables comparison among different driving structures within the same vehicle. In addition, from 2012, we utilized our advanced control technologies for EVs (vehicle stability control, range extension control algorithm, etc.) to start new work on an electric airplane. The development of theories and experiments related to this project is currently in progress.

Control of electric vehicles.
Control of electric vehicles.

Wireless Power Transfer System
We are currently researching a higher-efficiency wireless power transfer technology based on magnetic resonance coupling with longer distance. Wireless power transfer is appealing because it can counteract the disadvantages posed by using a battery in an EV. These batteries typically have a small capacity and therefore require frequent charging. A battery charger combined with wireless power transfer is more convenient for frequent charging than a conventional wired charger because the wireless charger can be used while the vehicle is running or when briefly stopped, as with electric trains. This enables EVs to perform well even with a small storage battery. Moreover, wireless power transfer via magnetic resonance has better characteristics than via conventional electromagnetic induction, including a larger air gap, higher transfer efficiency, and higher robustness of positional shifts. Our research includes (1) an explanation of magnetic resonance phenomenon using equivalent circuits, (2) a proposal of new antenna designs, (3) highly efficient power transfer systems with switching devices, (4) an improvement of power transfer efficiency based on impedance matching theories, and (5) wireless charging systems for electric vehicles.

Wireless power transfer system.
Wireless power transfer system.

Application of Supercapacitors
A supercapacitor (SC) used as an energy storage device has many advantages, including high power density, quick charging, and extended lifetime. In our lab, we have developed an electric vehicle called C-COMS powered only by SC that can operate for 20 minutes after a 30-second charging. The combination of SC-based storage systems and wireless charging technology is helping to establish a new era of Choco Choco charging (charge while driving) for future electric vehicles. For higher performance, we are developing an SC and battery hybrid energy storage system (HESS) with the objective of achieving both high energy density and high power density. As for the SC bank interface, we are developing a new DC-DC converter prototype that is smaller and more efficient. A new EV with HESS and a direct drive motor is now being developed for energy management and control with vehicular information.

Human-Friendly Motion Control
We aim to establish an academic field of ghuman-friendly motion controlh in order to develop unique control methods with welfare-related applications in mind. Two of our key interests are robots for use in daily life and in areas such as rehabilitation and control methods suitable for personal mobility devices. We are able to design the mechanical properties of devices freely by taking advantage of the high controllability of motors. We are also working on a new robotics system based on simple and efficient biomechanics with inspiration from the musculoskeletal characteristics of humans and other living species. Current research topics include (1) new robotic arms for biologically inspired biarticular actuation, (2) control design for power-assist wheelchairs that improve safety, handling, and comfort, (3) power-assist technologies for welfare prosthetic devices and caregiver robots, (4) application of biarticular actuators for human running and jumping, as well as robots that can achieve this, (5) precision control of humanoid robots, and (6) design of safe train doors and landing technologies for space probes using force sensor-less control.

Human-friendly motion control.
Human-friendly motion control.

See the lab homepage.

Other Activities
See the lab homepage.

Future Plan
See the next term.

Messages to Students
The three main pillars of Hori-Fujimoto Labfs research are control engineering, motion control, and power electronics. The essence of electrical control is feedback control, while that of mechanical control is open loop control. Electrical control, where a simple algorithm is repeated for a short control period, can drastically change mechanical characteristics. On the basis of this principle, we aim to revolutionize the fields of electric vehicles, nanoscale servo control, and human-friendly motion control. We are also closely invested in research on a wireless power transfer system, supercapacitor/battery hybrid energy storage system, and motor control for the next generation of vehicles.
To any person who wants to help the aged and the handicapped, who likes cars and wants to work in a motor company in the future, who likes moving things such as robots, and who wants to make electronic circuits or produce hardware: please, come to Hori Laboratory by all means. We have many outside acquaintances, and a characteristic of our work is that we receive many visitors to view our cars. In those cases, you will be asked to prepare for the meetings and sometimes to explain things. Therefore, you must be able to handle routine duties. Also, we should point out that Hori Lab is not suitable for the individual who prefers to do his or her own thing. Teamwork is required. I am happy to invite people who will warmly help each other if one is in need.