Proportional Joint Moment Controller¶

Description¶

This controller applies a torque to the ankle proportional to the normalized FSR reading of the toe. More details on this controller can be found in:

G. M. Gasparri, J. Luque and Z. F. Lerner (2019). Proportional Joint-Moment Control for Instantaneously Adaptive Ankle Exoskeleton Assistance. in IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 27, no. 4, pp. 751-759, doi: 10.1109/TNSRE.2019.2905979.

Parameter index order can be found in ControllerData.h.

stance_max: The peak torque, in Nm, during stance. When the normalized FSR is 1, this will be the torque applied to the ankle.
swing_max: The constant torque, in Nm, during swing. This will be a constant torque and is rarely used
is_assitance: When this is 1(assistive) the system will apply the torque in the plantar flexion direction, when 0(resistive) will be in the dorsiflexion direction
use_pid: This flag turns PID control on (1) or off (0)
p_gain: Proportional gain for closed-loop control
i_gain: Integral gain for closed-loop control
d_gain: Derivative gain for closed-loop control
torque_alpha: Filtering term for exponentially wieghted moving average (EWMA) filter, used on torque sensor to cut down on noise. The lower this value the higher the delay caused by the filtering