This article presents a new approach to the problem of compliant-motion planning of manipulators in which the dy namics of the environment are taken into account. The scheme is based on decoupled linear impedance models of the robot and the environment, for which the errors due to control, task- frame estimation, and environment uncertainty are explicitly taken into account. The technique consists of characterizing the position, velocity, and force responses of the decoupled models, and expressing the task goals as constraints on these expres sions. The impedance parameters of the controller are found by fitting uncertainty boxes inside the region of the parameter space that satisfies all task constraints. Two insertion examples, as well as an experimental verification of this method for the task of closing a circuit breaker, are presented.