Ixchel G. Ramirez-Alpizar, Kensuke Harada and Eiichi Yoshida
The aim of this work is to develop a simple planner that is able to automatically plan the motion for a dual-arm manipulator that assembles a ring-shaped elastic object into a…
Abstract
Purpose
The aim of this work is to develop a simple planner that is able to automatically plan the motion for a dual-arm manipulator that assembles a ring-shaped elastic object into a cylinder. Moreover, it is desirable to keep the amount of deformation as small as possible, because stretching the object can permanently change its size thus failing to perfectly fit in the cylindrical part and generating undesired gaps between the object and the cylinder.
Design/methodology/approach
The assembly task is divided in two parts: assembly task planning and assembly step planning. The first one computes key configurations of the robot’s end-effectors, and it is based on a simple heuristic method, whereas the latter computes the robot’s motion between key configurations using an optimization-based planner that includes a potential-energy-based cost function for minimizing the object’s deformation.
Findings
The optimization-based planner is shown to be effective for minimizing the deformation of the ring-shaped object. A simple heuristic approach is demonstrated to be valid for inserting deformable objects into a cylinder. Experimental results show that the object can be kept without deformation for the first part of the assembly task, thus reducing the time it is being stretched.
Originality value
A simple assembly planner for inserting ring-shaped deformable objects was developed and validated through several experiments. The proposed planner is able to insert ring-shaped objects without using any sensor (visual and/or force) feedback. The only feedback used is the position of the robot’s end-effectors, which is usually available for any robot.
Details
Keywords
A combination of new machines and new companies to make them is signalling a switch in emphasis from spot welding to arc welding robots in readiness for the next wave of increased…
Abstract
A combination of new machines and new companies to make them is signalling a switch in emphasis from spot welding to arc welding robots in readiness for the next wave of increased sales, though this does not mean spot welding robots are by any means dead.
This paper seeks: (1) to understand householding as an economic survival strategy by viewing new, historical, evidence in light of previous work on the theme, (2) to fill gaps in…
Abstract
Purpose
This paper seeks: (1) to understand householding as an economic survival strategy by viewing new, historical, evidence in light of previous work on the theme, (2) to fill gaps in the historical and anthropological literature on prewar Japanese farming villages that have resulted in an incomplete conceptualization of the household as a unit of production and consumption, and (3) to improve the overall comprehension of peasant behavior vis-à-vis questions about moral economy, ecological adaptation, and risk-taking.
Design/methodology/approach
The essay relies on information gleaned from a detailed 1935–1936 one-year diary of a small-scale farmer, published in 1938.
Findings
The prewar Japanese farming village was far more than a collection of households linked by sharing and reciprocal ties. It was not only a place where households as economic units of production and consumption were central, but one where individuals strived to obtain whatever they could, whenever they could. It appears that small-scale prewar Japanese farmers were as likely to take risks and to experiment in order to improve their lot as any other peasants around the world.
Originality/value
It adds to the understanding of prewar Japanese farming villages by presenting valuable historical data that has previously been unavailable in English. It also helps to better situate Japanese peasants in the context of global peasant culture and society, and improves understanding of developmental processes – especially in the case of 20th century Japan.
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E. Sato, M. Kashiwabara and S. Yoshida
The corrosion characteristics of lead alloy anodes for cathodic protection in sea‐water, at high or normal temperatures, were not available in detailed reports. A sea‐water intake…
Abstract
The corrosion characteristics of lead alloy anodes for cathodic protection in sea‐water, at high or normal temperatures, were not available in detailed reports. A sea‐water intake at normal temperature, and a gas condenser fitted with lead alloy anodes in high‐temperature sea‐water, were tested to examine the corrosive nature of alloys.