Repeatble positioning and accurate tracking with T-flex

Exploiting recent developments in flexure design, a large-stroke flexure-based parallel manipulator has been built. The hysteresis-free flexures enable high positioning repeatability, while the predictability of the dynamics allows for high-accuracy tracking by feedforward control. After the earlier introduction of the T-Flex, this article elaborates on its design, prototype realisation, control strategy and experimental results. Attention is also paid to the challenge posed by the absence of play and friction; the smallest variations in actuation force transfer to platform displacements directly. Design modifications to counteract this are discussed.