Effect on positioning accuracy due to assembly error of large robot for ITER blanket maintenance

Robots for ITER blanket maintenance are required to have high accuracy in positioning a blanket of 40 kN weight. Therefore it is important to know the effect of the assembly error of a robot on the accuracy of positioning a blanket. In the present study, the authors developed a model to evaluate the effect of the assembly error and examined the role of sensors on the positioning accuracy. As a result, contact sensors were found to give more accurate positioning than non-contact sensors independent of the assembly error. (author)