Soft exosuit for assistance with human motion

1 . A method of assisting muscle-driven motion of a lower limb joint of a user, comprising:

monitoring real-time measurements of at least one inertial sensor relating to a position of the lower limb joint and to an angular velocity of motion of the lower limb joint of the user;

detecting a movement event relating to an angular velocity of the motion of the lower limb joint based at least in part on the real-time measurements of the motion of the lower limb joint;

referencing a force profile comprising desired forces to be produced corresponding to each position in the lower limb joint motion as the lower limb joint is moved by the motion of the user;

generating an assistive profile configured to produce the desired forces; and

in response to the detection of the movement event relating to the angular velocity of the muscle-driven motion of the lower limb joint, actuating a motor of a wearable robotic system based at least in part on the assistive profile to produce the desired forces to assist the muscle-driven motion of the lower limb joint of the user.

2 . The method of claim 1 , further comprising determining a desired peak force and/or power to be generated by the wearable robotic system during a current motion cycle of a user.

3 . The method of claim 2 , wherein the assistive profile comprises an actuation profile according to which the motor of the wearable robotic system is actuated to move the wearable robotic system to positions configured to produce the desired forces to a body of the user, and further comprising actuating the wearable robotic system based at least in part on the actuation profile.

4 . The method of claim 3 , wherein the actuation profile comprises a trapezoidal position profile defining a succession of motor positions, including timings of initiation of motor positions and durations of motor positions.

5 . The method of claim 1 , wherein the lower limb joint comprises a hip joint of the user, and wherein the muscle-driven motion of the lower limb joint of the user that is assisted comprises at least one of hip flexion or hip extension.

6 . The method of claim 5 , wherein the lower limb joint is a hip joint and the movement event comprises:

when the hip joint of the user reaches a maximum flexion angle,

a sign change in angular velocity of the hip joint associated with an end of a hip flexion motion and a beginning of a subsequent hip extension motion, or

when an angle of the hip joint ceases an increase in magnitude associated with a flexion motion and begins to decrease in magnitude at a start of the subsequent extension motion.

7 . The method of claim 1 , further comprising terminating the actuation of the motor of the wearable robotic system when a measured motion of the lower limb joint subsequently reaches a predetermined angle and/or rotational velocity reaches zero.

8 . The method of claim 1 , wherein the wearable robotic system is a soft wearable exosuit, and the motor is configured to drive a tension element comprising one of a cable, fabric straps, webbing straps, or wiring, the tension element configured to be coupled to at least two anchors of the soft wearable exosuit, and configured to generate a tensile force that pulls the at least two anchors toward one another.

9 . The method of claim 1 , wherein the assistive profile comprises the referenced force profile, and wherein the generating an assistive profile configured to produce the desired forces comprises commanding the motor with the desired forces to be produced at each point in the motion of the lower limb joint of the user.

10 . The method of claim 1 ,

wherein the assistive profile comprises a curved force profile comprising motor forces to be applied as a function of the position of the lower limb joint of the user,

wherein the curved force profile defines the desired forces at each position in the motion of the lower limb joint, and increases desired force at a start position of assistance, rises towards a desired peak force, and falls off near an end position of assistance, and

further comprising:

actuating the motor of the wearable robotic system by motor force control.

11 . The method of claim 1 ,

wherein the at least one inertial sensor is configured to measure joint angle, joint motion direction, joint motion speed, and/or joint motion acceleration, and comprises a torso-mounted inertial measurement unit configured to be placed on a user's torso and thigh-mounted inertial measurement units configured to be placed on the user's respective thighs, and

wherein the measurements relating to the angular velocity of the lower limb joint of the user comprise a relative difference in angular velocity between the user's torso and thighs, and the measurements relating to the position of the lower limb joint comprise a relative angle between the user's torso and the thighs.

12 . The method of claim 1 , further comprising:

adjusting the desired forces in response to force feedback from a force sensor that is configured to measure tensile forces generated in the wearable robotic system.

13 . The method of claim 1 , further comprising:

receiving an adjustment of level of assistance to tailor the desired forces to be produced to one or more of: different users, different primary activities or tasks to be performed by a user, desired battery consumption, walking speed and/or inclination, carrying loads, or training accommodation; and

regulating the desired forces to be produced according to the adjustment.

14 . The method of claim 1 , wherein the lower limb joint is a hip joint and the movement event comprises:

when the hip joint is moving above or below a threshold speed, as indicated by a magnitude of the measured angular velocity,

when the joint is rotating in a particular direction, as indicated by a sign of the measured angular velocity, or

a detection of a combination of joint angle(s) and angular velocity(s).

15 . A wearable robotic system for assisting muscle-driven motion of a lower limb joint of a user, the system comprising:

at least one inertial sensor adapted to monitor real-time measurements relating to a position of the lower limb joint and to an angular velocity of motion of the lower limb joint of the user; and

at least one processor configured to:

detect a movement event relating to an angular velocity of the motion of the lower limb joint and based at least in part on the real-time measurements of the motion of the lower limb joint;

reference a force profile comprising desired forces to be produced corresponding to each position in the lower limb joint motion as the lower limb joint is moved by the motion of the user;

generate an assistive profile configured to produce the desired forces; and

in response to the detection of the joint movement event relating to the angular velocity of the motion of the lower limb joint, actuate a motor of the wearable robotic system based at least in part on the assistive profile to produce the desired forces to assist with the muscle-driven motion of the lower limb joint of the user.

16 . The wearable robotic system of claim 15 , wherein the at least one processor is configured to determine a desired peak force and/or power to be generated by the wearable robotic system during a current motion cycle of the user.

17 . The wearable robotic system of claim 15 , wherein the assistive profile comprises an actuation profile according to which the motor of the wearable robotic system is actuated to move the wearable robotic system to positions configured to produce the desired forces to a body of the user, and wherein the at least one processor is configured to actuate the motor based at least in part on the actuation profile.

18 . The wearable robotic system of claim 15 , wherein the lower limb joint comprises a hip joint of the user, and wherein the muscle-driven motion of the lower limb joint of the user to be assisted comprises at least one of hip extension or hip flexion.

19 . The wearable robotic system of claim 18 , wherein the movement event comprises:

when the hip joint of the user reaches a maximum flexion angle,

a sign change in angular velocity of the hip joint associated with an end of a hip flexion motion and a beginning of a subsequent hip extension motion, or

when an angle of the hip joint ceases an increase in magnitude associated with a flexion motion and begins to decrease in magnitude at a start of the subsequent extension motion.

20 . The wearable robotic system of claim 15 , wherein the processor is configured to terminate actuation of the motor of the wearable robotic system when the lower limb joint reaches a predetermined angle and/or rotational velocity reaches zero.

21 . The wearable robotic system of claim 15 , wherein the wearable robotic system comprises a soft wearable exosuit, and the motor is configured to drive a tension element, comprising one of a cable, fabric straps, webbing straps, or wiring, coupled to at least two anchors of the soft wearable exosuit, and configured to generate a tensile force that pulls the at least two anchors toward one another.

22 . The wearable robotic system of claim 15 , wherein the assistive profile comprises the referenced force profile, and wherein the at least one processor is configured to generate the assistive profile configured to produce the desired forces by at least commanding the motor with the desired forces to be produced at each point in the motion of the lower limb joint of the user.

23 . The wearable robotic system of claim 15 ,

wherein the assistive profile comprises a curved force profile comprising motor forces to be applied as a function of the position of the lower limb joint of the user,

wherein the curved force profile comprises desired forces at each position in the motion of the lower limb joint, and increases desired force at a start position of assistance, rises towards a desired peak force, and falls off near an end position of assistance, and

wherein the at least one processor is configured to actuate the motor of the wearable robotic system by motor force control.

24 . The wearable robotic system of claim 15 ,

wherein the at least one inertial sensor is configured to measure joint angle, joint motion direction, joint motion speed, and/or joint motion acceleration, and comprises a torso-mounted inertial measurement unit configured to be placed on a user's torso and thigh-mounted inertial measurement units configured to be placed on the user's respective thighs, and

wherein the measurements relating to the angular velocity of the lower limb joint of the user comprise a relative difference in angular velocity between the user's torso and thighs, and the measurements relating to the position of the lower limb joint comprise a relative angle between the user's torso and the thighs.

25 . The wearable robotic system of claim 15 , wherein the at least one processor is configured to adjust the desired forces in response to force feedback from a force sensor that is configured to measure tensile forces generated in the wearable robotic system.

26 . The wearable robotic system of claim 15 , wherein the at least one processor is further configured to:

receive an adjustment of a level of assistance to tailor the desired forces to be produced to one or more of: different users, different primary activities or tasks to be performed by a user, desired battery consumption, walking speed and/or inclination, carrying loads, or training accommodation; and

regulating the desired forces to be produced by the wearable robotic system according to the adjustment.

27 . The wearable robotic system of claim 15 , wherein the joint movement event comprises:

when the joint is moving above or below a threshold speed, as indicated by a magnitude of the measured angular velocity,

when the joint is rotating in a particular direction, as indicated by a sign of the measured angular velocity, or

a detection of a combination of joint angle(s) and angular velocity(s).

28 . A wearable soft exosuit for motion assistance to a lower limb joint of a user, comprising:

a motor configured to generate tensile forces in the soft exosuit;

first inertial motion sensors configured for positioning on a user's thighs, and to measure the user's thigh motion;

second inertial motion sensors configured for positioning on the user's torso, and to measure the user's torso motion;

a force sensor configured to measure the tensile forces generated by the motor; and

a controller configured to:

monitor in real time the measurements of user's thigh motion and torso motion,

determine the user's lower limb joint motion, including an angle of the lower limb joint and an angular velocity of the lower limb joint, by relative difference between the user's thigh motion to the user's torso motion,

reference a force profile to be produced in the wearable soft exosuit and delivered to the user's body to assist the user's lower limb joint motion, the force profile defining a desired force magnitude to be produced at each point in the user's lower limb joint motion,

actuate the motor to generate tensile forces in soft exosuit assisting the user's lower limb joint motion in response to an initiation trigger comprising a joint movement event based upon at least a measured angular velocity of the lower limb joint, in which:

the user's lower limb joint has reached a predetermined angular velocity magnitude,

the user's lower limb joint is rotating in a predetermined direction as indicated by a sign of the measured angular velocity, or

the user's lower limb joint has reached a predetermined combination of angle and angular velocity of the lower limb joint, and

adjust the magnitude of the actuation in real-time according to measurements from the force sensor to compensate for a difference between the force profile and the measured tensile forces.