Takeshi Tsujimura

Object detection by tactile sensing method employing force/torque information

An object shape detection system using a force/torque sensor and an insensitive probe is proposed. the development of a tactile sensing method is which makes it possible to estimate a contact position on the probe by measuring only contact force is presented. Though the probe itself is not sensitive, the method derives the contact position from force information measured by the sensor. The estimated values do not depend on either the magnitude or the direction of the force. The method can be with any probes of any shape and material. This method is applied to a manipulator system, and object shape detection experiments are conducted using two types of probes. Shapes of three-dimensional objects are successfully reproduced. The results confirm that the method enables the manipulator system to detect objects without precise control. >

A Wire Mobile Robot with Multi-unit Structure

This paper proposes a mechanism and a control system for a wire mobile robot with a multi-unit structure The mobile robot has an ultrasonic sensing system for environment recognition enabling it to move autonomously With this mechanism, control and sensing system, the robot can transfer to a branch wire and avoid obstacles on the wire This paper first clarifies the design of a mechanism and a method for avoiding obstacles and transferring the robot to a branch wire Then it shows experimental results using a prototype of mobile robot with an ultrasonic sensing system

Force control of servomechanism using adaptive control

It is shown that a servomechanism with only position/velocity functions can obtain a force control function using the adaptive theory (model-referenced adaptive system and model-referenced control). Experimental results of both the servomechanism and the single-degree-of-freedom force control of the manipulator show that this method leads to suitable force control when the object stiffness changes greatly. The advantage of this method is that a force control function is achieved by implementing software to identify the object stiffness without changing hardware. >

Three‐dimensional shape recognition method using ultrasonics for manipulator control system

This article describes a three-dimensional shape recognition method that employs an ultrasonic distance sensor mounted on a manipulator, and its application to a manipulator control system. The principle of the method is to reconstruct an object surface numerically using both distance and orientation informations of an object. The method makes it possible to control the manipulator, to set the sensor in any position and orientation employing freedom of the manipulator, and to measure the object. The method is available for manipulator control because it can precisely assess the distance from the manipulator to the object, as well as reconstruct the object shape. Experimental results show that the newly developed method make object shape recognition easy and inexpensive. Application experiment proved that the method is effective for manipulator work due to its provision of distance information.

Tactile Sensing Techniques in Robotic Systems

ABSTRACT This paper proposes an object shape detection system using a force/torque sensor and an insensitive probe. Tactile sensing method has newly been developed, which makes it possible to estimate a contact position on the probe only by measuring contact force. Though the probe itself is not sensitive, the method derives the contact position from force information measured by the sensor. The estimated values do not depend on either the magnitude or the direction of the force. The method is available with any shape and any material of probe. This method has been applied to a manipulator system, and object shape detection experiments have been conducted using two types of probes. Shapes of three dimensional objects have successfully been reproduced. The results confirm that the proposed method enables the manipulator system to detect objects without precise control of the manipulator.

Study on Tensile Strength of Resin Mortar

A new resin mortar has been developed to facilitate a small-diameter shield tunneling method. The breaking elongation, Young’s modulus and tensile strength of the resin mortar are measured and studied. This paper clarifies the relationship between the mechanical properties of the resin mortar and the ones of its constituent materials, using a three-spring model. The mechanical properties of the resin mortar predicted from the model proposed in this paper agree with the measured values.