The learning technologies for picking tasks presentedin the preceding sections use images and convolutionalneural networks. Robot sensors such as force sensors andtactile sensors mostly provide time-series information.Among the networks effective for learning from suchtime-series information, the Recurrent Neural Network(RNN) [45] and Long Short-Term Memory (LSTM) [46]have been widely used to make industrial robots more in-telligent. Hatori et al. connected an LSTM-based voicerecognition network to their robot and demonstrated bin-picking based on voice interactions [47]. Yang et al.demonstrated their robot’s RNN-based learning to fold uptowels in many different colors and shapes [48]. Gu et al.had their robot learn to open and close a door based on itsreinforcement learning [49]. Finn et al. had their robot ac-quire motions to shift picked objects sideways [50]. Ref-erence [51] succeeded in a robot learning a task in aninvisible state hidden from its vision sensor, combinedwith a tactile sensor. Machine learning is sure to becomean increasingly important technology for robotic object-manipulation tasks.