Yukio Hashiguchi

Automatic insertion work based on visual measurement and contact force estimation

This paper focuses on the automation of insertion work, such as inserting a metal sleeve into a wire terminal, necessary in distribution work. The major technical issues for this task automation are considered as: the detection of a target object in an unstructured, complex outdoor environment; and the insertion executed at the work site with restricted clearance. In the former, the target object is detected by applying 3D image processing and template matching techniques, based on the position and posture relationship between CCD cameras, the target object, and the background. In addition, the manipulators targeting position is updated by commands from the visual sensor system, applying the video-rate stereo camera method. This allows for realtime visual feedback control; thus, misalignment due to deviation arising from manipulators mechanism is avoided. In the latter issue, a new algorithm was developed for insertion. This algorithm can estimate contact force, based on the deviation between the present position and command position of the manipulator. An experiment using a testing robotic system revealed that the proposed robotic technology was effective for performing insertion work without assistance by humans.

The development of a practical dexterous assembly robot system without the use of force sensor

In this paper, we propose a practical dexterous assembly robot system without the use of the force sensor. This system is composed of skill based control architecture and executes complex tasks such as assembly of RV gear by combining some basic skill sets. Among these skill sets, gear mating skill generating two kinds of characteristic rotary motions simultaneously is the most important skill for achieving dexterous assembly tasks. The goal state recognition of this skill is made by using only internal position data of a robot. This approach without using force sensor has made this system low priced. The effectiveness of this system is demonstrated through MOTOMAN RV gear unit assembly tasks.

Automation of assembly task in distribution power line work and its application to outdoor environment field

This paper describes the practical application of robot vision techniques to electricity distribution work. To cope with variable outdoor lighting conditions and diverse backgrounds due to unstructured outdoor environments, we have developed two methods of detecting an objects 3D position using both 2D gray-scale image and 3D range image. The first method locates a target object as a 2D image taken at a distance. Although the resolution of a 3D range image taken from the same position is too low to extract the objects surface geometry, it is effective to eliminate the background section from the 2D image based on the distance threshold. The second method generates an online template image of the object to be worked on. This enables reliable real-time visual tracking by stereovision despite the variations of the objects shape and appearance. Here we show how these methods are implemented and effectively used in distribution work.