Reactive layer control system for prosthetic and orthotic devices

An apparatus, comprising:

• an actuator coupled to a prosthetic limb member, the actuator forming at least a portion of a joint of the apparatus;
• a force sensor configured to output a first signal indicative of an interaction between the apparatus and ground;
• a torque sensor configured to output a second signal indicative of torque at the joint;
• a position sensor configured to output a third signal indicative of position of the joint;
• and
• a variable gain impedance controller comprising a processor in communication with the force sensor and the torque sensor, the processor configured to:
• receive the first signal from the force sensor, the second signal from the torque sensor, and the third signal from the position sensor,
• based at least in part on the first signal, determine a torque feedback, wherein during stance phase the torque feedback is determined using the torque and a first gain factor and during swing phase the torque feedback is determined using the torque and a second gain factor that is different from the first gain factor,
• determine a variable velocity gain and a variable position gain based at least in part on the first signal indicative of the interaction between the apparatus and the ground, and
• output a control signal to the actuator based at least in part on the variable velocity gain, a difference between a velocity set-point and a velocity estimation of the apparatus, the variable position gain, a difference between a position set-point and the third signal indicative of the position of the joint, and the torque feedback, wherein based at least in part on the torque feedback determined using the first gain factor, the control signal causes the actuator to increase joint resistance to motion and based at least in part on the torque feedback determined using the second gain factor, the control signal causes the actuator to decrease joint resistance to motion.