Hajime Terasaki

Conversion system of monocular image sequence to stereo using motion parallax

A three-dimensional reconstruction system -- the 3DR system -- has been developed. The main feature of the 3DR system is that it converts monocular image sequences to stereoscopic ones. This provides the following advantages: (1) Stereoscopic images can be reproduced even from films taken in the past. (2) A compact 3D-scene capturing system using a monocular camera is realized. The key 3DR technology is depth sensing based on motion parallax. A novel technique for motion analysis is proposed where, according to classification of motion vectors using the stability and colinearity, an iterative operation is performed to obtain an accurate solution. Preliminary evaluations have shown that not only was the motion parallax analyzed very accurately but also stereoscopic images of high quality were generated.

Collision avoidance: divide-and-conquer approach by space characterization and intermediate goals

An efficient method that finds collision-free paths for a manipulator with six revolute joints is described. A global structure of the free space in the three-dimensional (3-D) joint space of the arm of a large open space in the workspace, defined as a space where any orientation of the hand is possible, is represented in this description. >

Motion planning of intelligent manipulation by a parallel two-fingered gripper equipped with a simple rotating mechanism

This paper focuses on motion planning of a manipulator equipped with a parallel two-fingered gripper to execute a primitive task, i.e., moving an object to a goal pose. In a complex situation, the goal cannot be achieved in a single grasp, We propose a new, realistic approach to achieve the complex goal. In this approach, the goal can be reached by intelligent manipulations, which are planned by intelligently selecting and combining simple manipulations. This paper describes a method of motion planning of intelligent manipulations consisting of picking, placing, sliding, and rotating manipulations by a parallel two-fingered gripper. The rotating manipulation by gravity has been realized by a new small and simple mechanism we have developed and attached to a parallel two-fingered gripper. This system plans motions by adaptively selecting and combining these four simple manipulations to achieve the goal. We describe the implementation including motion planning for rotating manipulations, a searching algorithm, results of our application and the validity of this system.

Automatic grasping and regrasping by space characterization for pick-and-place operations

This paper describes a method of planning grasps for parallel two-fingered grippers in order to pick up user-specified objects and place them at user-specified configurations. By characterizing local space around gripping positions, the method can plan grasps where the hand can move as freely as possible and then easily plan a path. It can plan regrasping where the grasps themselves and the regrasping placements are computed flexibly according to the environment. It can plan minimal sequences of regraspings for objects that have rotational symmetries.<<ETX>>

Motion planning for intelligent manipulations by sliding and rotating operations with parallel two-fingered grippers

Humans have numerous manipulation skills which they can intelligently combine to execute tasks. The authors have developed motion planning systems for intelligent manipulations using parallel two-fingered grippers. They propose a new method to integrate these motion planning systems. The basic idea of this method is the state-space approach which is described in states and operators and solves problems by searching state-space from initial state to goal state. The operators correspond to the primitive manipulation skills and transform a state into another state. This method was applied to a manipulator equipped with a parallel two-fingered gripper. The key idea behind this application is to augment the handling ability of a parallel two-fingered gripper, instead of developing a difficult and complicated control method that uses a sophisticated but weak multifingered gripper. To actually implement this idea, we have developed a new, small and simple mechanism attached to a parallel two-fingered gripper.<<ETX>>