Hybrid terrain-adaptive lower-extremity systems

A method for minimizing the effect of accelerometer and rate gyro errors on a lower extremity prosthesis or orthosis comprising a foot member, a lower leg member, and an ankle joint for connecting the foot member to the lower leg member, the method comprising:

• determining at least one velocity error contribution for an accelerometer signal output by an accelerometer coupled to the lower leg member when the ankle joint is substantially stationary during a walking cycle of the prosthesis or orthosis;
• and
• determining at least one velocity error contribution for an inertial pose misalignment signal output by an inertial measurement unit coupled to the lower leg member when the ankle joint is substantially stationary during a walking cycle of the prosthesis or orthosis.

A method for controlling balance of a wearer wearing a lower extremity prosthetic, orthotic or exoskeleton apparatus comprising a foot member, a lower leg member, and an ankle joint for connecting the foot member to the lower leg member, the method comprising:

• adjusting at least one of the ankle joint impedance, position or torque of the apparatus based on inertial pose of the lower leg member, angle between the lower leg member and the foot member and ground reaction force and the zero moment pivot imparted by an underlying surface onto the foot member.

A method for reducing, throughout a gait cycle, hip impact force and hip impact force rate of a lower-extremity prosthetic, orthotic, or exoskeleton apparatus worn by a wearer, the method comprising:

• generating a cost function based on hip impact force and force rate generated by transmission of foot contact with underlying terrain;
• and
• controlling at least one of position, impedance or torque of at least one joint of the lower-extremity prosthetic, orthotic, or exoskeleton apparatus based on minimizing the cost function wearer to reducing hip impact forces generated during a gait cycle over the underlying terrain.

A method for minimizing, throughout a gait cycle, work performed by a lower-extremity prosthetic, orthotic, or exoskeleton apparatus worn by a wearer, the method comprising:

• generating a cost function for estimating intra-step transition work performed by a combination of the apparatus and subject on center of mass of the combination during double support;
• and
• controlling at least one of position, impedance or torque of at least one joint of the lower-extremity prosthetic, orthotic, or exoskeleton apparatus based on minimizing the cost function wearer to reducing the work performed by the wearer and apparatus generated during a gait cycle.