A system capable of controlling an autonomous walking assist rhythm, while following changes in a walking rhythm of a walker at the same time. A control system 100 in accordance with the present invention generates a first oscillator x that tugs and is tugged by a walking oscillator (hip joint angular velocity) φH′ such that an intrinsic angular velocity is reflected. Then, a new intrinsic angular velocity ωm is determined on the basis of the difference between a first phase difference θHM between the first oscillator x and the walking oscillator φH′ and a desired phase difference θd. Furthermore, a second oscillator y is generated that tugs and is tugged by the walking oscillator φH′ such that the intrinsic angular velocity ωm is reflected, and has a second phase difference θhm, which is closer to the desired phase difference θd than the first phase difference θHM is, with respect to the walking oscillator φH′. Then, based on the second oscillator y and the walking oscillator (hip joint angle) φH, a walking assist oscillator (torque imparted to the walker by a walking assist unit 200) T is generated.