Shinsaku Fujimoto

Evaluation of an in-motion vehicle weighing method via Grey estimation model

A novel weighing method for in-motion vehicles is set up in this paper. The measurement principle is described and an estimation of measurement uncertainty using Grey Error Theory is presented. Theoretical analysis and experimental research are given to show that the method could be used to solve the weighing problem for in-motion vehicles with higher accuracy.

3D quasi-passive walking of bipedal robot with flat feet: quasi-passive walker driven by antagonistic pneumatic artificial muscle

In this paper, We develop three-dimensional quasi-passive walker with flat feet driven by an antagonistic pneumatic artificial muscle. An antagonistic mechanism is constituted by a pair of McKibben muscles. And an antagonistic pneumatic system is used as joint actuators of linkage mechanisms which control the torque, joint stiffness and position simultaneously. However, it is more difficult to control the pneumatic actuator than a usual electric motor. Therefore, we also examined the structure of an ankle and the control method of an antagonistic pneumatic system. As a result, a three-dimensional quasi-passive walking is realizable by means of adjusting the stiffness of an ankle joint. From experimental results of quasi-passive walking, the average gait were obtained with the travel distance 1350 mm, the stride of a step 90 mm, and the number of steps 15 steps. It was demonstrated that the quasi-passive walking is stabilized when both the robotic motions in a lateral plane and in a sagittal plane are synchronized.

Development of Flexible Pneumatic Cylinder with String-Type Displacement Sensor for Flexible Spherical Actuator

This study aims at developing a potable rehabilitation device which can be safe to use while holding it. In our previous study, a novel flexible pneumatic cylinder that can be used even if it is deformed by external force has been developed. A portable rehabilitation device using the flexible spherical actuator that consists of two ring-shaped flexible pneumatic cylinders was proposed and tested. The attitude control system using a tiny embedded controller, four small-sized quasi-servo valves, and two accelerometers was also proposed and constructed. The attitude control of the device was executed. In the next step, it is necessary to recognize the relative position between both stages to prevent both hands to contact each other. In this study, the low-cost flexible displacement sensor using the nylon string coated with carbon is proposed and tested. As a result, it is confirmed that the tested sensor can measure the displacement of the cylinder.

Analytical Model of Pipe Inspection Robot Using Flexible Pneumatic Cylinder

A pipe inspection robot is useful to reduce the inspection cost. In our previous study, a novel pipe inspection robot using a flexible pneumatic cylinder that can be driven even if it bends has been proposed and tested. The built-in pneumatic driving system using a tiny embedded controller and small-sized valves have also been proposed and tested to decrease the mass of the robot for increasing inspection area. In this chapter, in order to find out the optimal driving pattern and length of the robot, an analytical model of the pipe inspection robot is proposed. The model consists of two on/off control valves and a sliding mechanism which is composed of a flexible pneumatic cylinder.

Development of Active Orthosis for Lumbago Relief

It is important to develop the orthosis which improves the Quality of Life (QOL) and maintains health conditions. As one of the treatment methods done to lumbago, the waist fixation method with the spinal brace or the orthosis is performed. A waist active orthosis implemented with pneumatic flexible actuators is developed and pressure control method of pneumatic flexible actuators is established. Orthosis control valve (on/off valve) system is modeled and the reliability of exhaust and supply model has been validated through experiment. The Effectiveness of the proposed control method has been validated through the control experiment using the orthosis control valve.

3D Quasi-Passive Walker of Bipedal Robot with Flat Feet Gait Analysis of 3D Quasi-Passive Walking

In this paper, we analysis gaits of 3D quasi-passive walker with flat feet driven by an antagonistic pneumatic artificial muscle. Many bipedal robots have been proposed to realize the high energy efficiency walking. The passive dynamic walking does not require control input. Generally, a foot shape of passive dynamic walking robot is an arc foot. It is intended to establish a control method and walking mechanism to achieve energy efficient and stable gait. Therefore, we developed 3D quasi-passive walker with flat feet. An antagonistic mechanism is constituted by a pair of McKibben muscle. And an antagonistic pneumatic system is used as joint actuators of linkage mechanisms which control the torque, joint stiffness and position simultaneously. This paper shows that the 3D quasi-passive walking in the level ground can realize by the simple swinging (sine) input of the frontal direction, and the stride of the robot is proportional to lateral-plane input. Finally, we examine the structure of an ankle, the control method of an antagonistic pneumatic system and these gaits analysis using COP (Center Of Pressure) and ROS (Roll-Over Shapes).