Robots with kinematical redundancy under the pseudoinverse control exhibit undesirable chaotic joint motion, which leads to erratic behaviors. In this study, we used the delayed feedback method to control chaotic motions of a planar 3R rigid and a planar 3R flexible redundant robot under the pseudoinverse control when the end-effector traces a closed-path repeatedly in the work space. It was demonstrated that chaotic motions of robots with kinematical redundancy can be turned into regular motion when the delayed feedback method was applied with some appropriate parameters. This study provides a new insight helpful to solve the repeatability problem of redundant manipulators.