Takahiro Matsuno

Study on air inflow of a passive suction cup

It is necessary to know the air inflow of suction cup for the designing of a new passive suction cup, which not only could easily attach and detach, but also could keep long adsorption time. This paper proposes a method to calculate the air inflow and its speed, which is easy to implement since it only requires a pressure sensor. Before calculating the air inflow, the factors affecting it should be known. In order to find this factors, experiments are conducted to find the effect of diameter, material, pulled height of displacement of a suction cup and wall condition.

Development of a suction cup with a disc spring

This paper presents a new suction cup with a disc spring for exiting adsorption mechanisms (for example, wall-climbing robots). The center of the suction cup can be pulled up manually through the use of buckling of the disc spring. When deformation of the disc spring reaches a certain balance point, it can sufficiently generate adsorption force. However, with time, the adsorption force will gradually decrease because of air inflow into the suction cup. Then, the spring can be automatically pulled up again to next balance point according to the air inflow. Repeating this process enables the adsorption for a long duration. By pushing back the disc spring to the original position manually, the suction cup is easily detached from the wall. This proposed suction cup can achieve long adsorption, easy attachment and detachment, and energy saving. In this paper, analysis of the adsorption force, design of the suction cup, and experiment of the prototype are conducted.

Guide rail design for a passive suction cup based wall-climbing robot

This paper designs a guide rail for a wall-climbing robot based on passive suction cups. The designed guide rail can guarantee stable climbing of a wall-climbing robot. Firstly, to design the parameters of the guide rail, properties of the utilized passive suction cup are experimentally studied. Then a guide rail is designed to distribute the forces of the attached suction cups. It guarantees that the front attached suction cup of the robot obtains a large enough reaction force from the attached surface. Experimental results show that the robot prototype with the designed guide rail is able to stably climb a surface without falling off, since the front suction cup of the robot prototype can be completely attached to the climbing surface.

Grasping state estimation of printable soft gripper using electro-conductive yarn

Abstract Automatic handling of many types of food materials are required to realize the automation of production of commercially prepared box lunches. A printable soft gripper was developed for food handling which is simple to produce with a 3D printer. However, the sensing ability of the printable soft gripper was not discussed in previous research. In this paper, a novel method for estimating the grasping state of a printable soft gripper using electro-conductive yarn is presented. Electro-conductive yarn is a conductive material, and the resistance of strings is changed by stretching. It is less expensive than other sensors that can be used for measurement of grasping state. Additionally, it is easy to assemble and disassemble by hand. Electro-conductive yarn is applied to a prototype printable soft gripper, and the proposed estimation method is verified experimentally. From the experimental results, the estimated grasping state from the resistance of the electro-conductive yarn coincides with the actual grasping state of the gripper. Our proposed method of using electro-conductive yarn was successful for estimating the grasping state of a printable soft gripper.

Development of remote robot control system for snake-like robot based on SSH protocol and iOS system

Remote robot control system has been applied for various purposes, such as inspection and monitoring. The next generation of remote robot control system is asked to be utilized efficiently and conveniently via Internet protocol (IP) based network. However, a critical issue about security of the IP based system is network attacks, which is need to be prevented. In this paper, we propose an iOS (Apple Mobile Operating System) based application with SSH (Secure Shell) protocol to realize teleoperation with a snake-like robot via Wi-Fi network. The system is divided into three modules, motion module, middleware module and teleoperation module. Arduino Nano microcontroller board, BeagleBone Black board installed Ubuntu operating system and iPhone 6 were used as calculation units. Experiments were conducted to show the validity of the system.

Design of spring-suspended suction cup based on the air inflow change with inside negative pressure

The safety of working on walls has been improved by several adsorption mechanisms most of which sustain the absorption by pumps or other actuators. This research proposes an alternative method (a spring-suspended suction cup with a buckled plate spring) that can be attached for long durations without any vacuum pumping system. The negative pressure of the spring suspended suction cup is analyzed and the buckled plate spring is appraised by the energy efficiency and force over long adsorption times of the suction cup. The adhesion time of the suction cup is calculated and compared with that of the volume-fixed suction cup. Under high air inflow conditions, the spring-suspended suction cup adhered to the test surface for longer than the fixed-volume cup. The advantages of the spring-suspended suction cup were verified in experiments on a developed prototype.

Real time prediction of suction cup's negative pressure decrement without previous measurement of air inflow speed

When a suction cup is attached to a surface, air inflow happens inevitably which affects the safety of the application using the suction cup. Therefore, the prediction of suction cups negative pressure decrement is important for enhancing safety of attachment. This study proposes a prediction method of negative pressure decrement in the attached state of the suction cup. It does not require previous measurement data of the relationship between negative pressure of suction cup and air inflow speed to suction cup. The unknown air inflow speed is estimated by polynomial approximation. The proposed estimation method is applied to a suction cup, and estimation results are verified with experiment.