In recent years, commercial applications for the teleoperation of wheeled humanoids have been progressing, and research and development of related technologies have been active. However, it is difficult to simultaneously control the upper and lower body with haptic feedback because wheeled humanoids often use a glove-type device to provide haptic feedback to each finger of the operator, and the controller must be held in the operator's hand during movement operations. On the other hand, research has been conducted to perform movement operations using only the lower limbs. Still, it has yet to reproduce the contact force in reality in force presentation.

　Therefore, we are developing an interface called “FRIC” (Foot Reactive and Intuitive Controller). It enables the user to control a humanoid robot only with its lower limbs by applying dimensional scaling bilateral control, enabling force presentation in a realistic contact state. Currently, focusing only on the lower limbs of the wheeled humanoid, the FRIC enables forward-backward and left-right turning movements. At the same time, the operator acquires information about the road surface environment on which the wheeled mobile robot runs, collisions with obstacles, etc.

　In addition, synchronization of position and force information between FRIC (leader device) and wheeled mobile robot (follower device) is essential for this system's dimensional scaling bilateral control. In the running experiment using the actual robot, we can see that the position and force are synchronized, as shown in the figure, and this confirms that the robot can understand the road surface environment when it runs on a flat floor and grass surface and can perceive the impact when it hits a wall as a sense of force.

　In the future, to enable more intuitive and safer maneuvering, we aim to realize omnidirectional movement and omnidirectional force presentation, as well as virtual repulsion forces from obstacles depending on the distance. In the future, we plan to construct a system using a wheeled humanoid that allows the operator to acquire information about the driving environment via FRIC while performing delicate tasks with the upper limbs.