Method and device for controlling walking assist device

A device configured to control a walking assist device, the device comprising:

• a memory;
• and
• a controller configured to control an assist torque provided by the walking assist device based on a gait of a user wearing the walking assist device by,
• determining a first state variable for a gait phase of the user based on the gait,
• obtaining a second state variable by smoothing and time-delaying the first state variable,
• determining a torque control variable based on the gait phase in a gait cycle of the user,
• obtaining a third state variable by applying the torque control variable to the second state variable, and
• determining the assist torque to be provided by the walking assist device based on the third state variable,
• wherein, in a learning mode for individualizing the walking assist device to be suitable for the user, the determining of the torque control variable comprises updating a parameter associated with controlling the assist torque to be provided by the walking assist device by selectively adjusting the torque control variable during a set gait phase of each gait cycle by (i) determining a walking assistance power index indicating an efficiency of the assist torque provided by the walking assist device to the user during a previous gait cycle, and (ii) adjusting the torque control variable associated with a current gait cycle based on the walking assistance power index, and
• wherein, in a normal mode, the determining of the torque control variable comprises determining the torque control variable based on the updated parameter derived from a learning result of the learning mode of the walking assist device.

A walking assist device comprising:

• a sensor configured to measure a gait of a user wearing the walking assist device;
• a driver configured to operate an actuator of the walking assist device to provide an assist torque to the user based on a torque control signal;
• and
• a controller configured to generate the torque control signal to control the assist torque based on the gait measured by the sensor by,
• determining a first state variable for a gait phase of the user based on the gait,
• obtaining a second state variable by smoothing and time-delaying the first state variable,
• determining a torque control variable based on the gait phase in a gait cycle of the user,
• obtaining a third state variable by applying the torque control variable to the second state variable, and
• determining the assist torque provided by the walking assist device based on the third state variable,
• wherein, in a learning mode for individualizing the walking assist device to be suitable for the user, the determining of the torque control variable comprises updating a parameter associated with controlling the assist torque to be provided by the walking assist device by selectively adjusting the torque control variable during a set gait phase of each gait cycle by (i) determining a walking assistance power index indicating an efficiency of the assist torque provided by the walking assist device to the user during a previous gait cycle, and (ii) adjusting the torque control variable associated with a current gait cycle based on the walking assistance power index, and
• wherein, in a normal mode, the determining of the torque control variable comprises determining the torque control variable based on the updated parameter derived from a learning result of the learning mode of the walking assist device.