Yuji Tsusaka

Posture stabilization for a personal mobility robot using feedback compensation with an unstable pole

The present paper introduces a novel posture control approach using feedback compensation with an unstable pole. A narrow and small personal mobility robot (PMR) requires control of its posture in order to achieve quick turning and high acceleration. However, in the conventional control approach that uses the posture angle as a controlled variable, the zero moment point (ZMP) cannot be set to the desired point if an unknown disturbance force acts on the PMR, if the center of gravity of the PMR fluctuates, or if the conditions between the tires and the road surface change. In the present paper, a novel control method using feedback compensation with an unstable pole is proposed in order to achieve the desired ZMP at the steady state. The proposed controller changes the control input for the actuator of the posture control to zero in order to achieve the desired posture angle. The effectiveness of the proposed approach is verified experimentally using a prototype PMR.

Wire-Driven Bipedal Robot

In this paper, a novel mechanical structure and original control architecture for a wire-driven bipedal robot are introduced. Whereas conventional direct motor driven bipedal robots are bulky and consume a lot of power, the worlds first wire-driven bipedal humanoid robot introduced in this paper is lightweight, flexible, and power efficient. This architecture is accomplished via an innovative arrangement of actuators that reflects human muscle concentrations. Furthermore, this design reduces the risk of injury, making it safer for human interaction

Development of a fast assembly robot arm with joint torque sensory feedback control

We have developed a new robot arm with six joints that have torque sensors and geared reduction systems. This arm has compliance control ability without using a wrist force sensor. The techniques adopted here are the low friction and low gear ratio reduction system, nonlinear torque compensation, inertial torque feedforward compensation and joint torque control using joint torque sensor feedback. The experimental results show that this robot has high accuracy of trajectory in spite of large compliance, i.e. low position feedback gains. This robot can also take practical industrial tasks in high speed under uncertain positioning of works.

Suppression of roll vibration for personal mobility robot using driving torque of wheels

The present paper introduces a novel control approach to suppress the roll vibration for the personal mobility robot (PMR)[1] using the driving torque of the wheels. The several types of intelligence technologies, such as localization, environment recognition, autonomous locomotion, driving assistance, and mapping, are being developed for the PMR in order to support comfortable driving [2][3]. On the other hand, in the case of the PMR, it is important to improve the performance of the vehicle motion. However, roll vibration can easily occur when the PMR travels on bumpy roads or turns quickly. Therefore, a novel control approach is proposed in order to suppress the roll vibration without the additional actuators or mechanisms. The effectiveness of the proposed approach has been verified by conducting simulations and experiments using a prototype PMR.