Patent ID: 8287473

Claim:
A motion assist device for assisting a user's motion by applying a force varying with respect to time in accordance with an assist oscillator to a user's body, comprising: a motion oscillator measurement element configured to measure motion oscillators serving as parameters that vary with respect to time responsive to movements of two different body parts of the user as first and second motion oscillators, respectively; a first oscillator generation element configured to generate a first oscillator as a first output oscillation signal by inputting the first motion oscillator measured by the motion oscillator measurement element to a first model as a first input oscillation signal, the first model being for generating the first output oscillation signal that attains mutual entrainment with the first input oscillation signal and varies with respect to time at an angular velocity determined according to a natural angular velocity; a natural angular velocity setting element configured to newly set the natural angular velocity in such a way as to bring a first phase difference corresponding to a phase difference between the first motion oscillator measured by the motion oscillator measurement element and the first oscillator generated by the first oscillator generation element close to a target phase difference; a second oscillator generation element configured to generate a second oscillator as a second output oscillation signal by inputting the second motion oscillator measured by the motion oscillator measurement element to a second model as a second input oscillation signal, the second model being for generating the second output oscillation signal that varies with respect to time at an angular velocity determined according to the natural angular velocity set by the natural angular velocity setting element on the basis of the input oscillation signal; and an assist oscillator generation element configured to generate the assist oscillator on the basis of the second oscillator generated by the second oscillator generation element, wherein the motion oscillator measurement element is configured to measure a joint angle of an upper limb of the user or its time derivative as the first motion oscillator and a joint angle of a lower limb of the user or its time derivative as the second motion oscillator, or to measure a joint angle of a lower limb of the user or its time derivative as the first motion oscillator and a joint angle of an upper limb of the user or its time derivative as the second motion oscillator.