Resumen del producto

Rehabilitation and assistance exoskeletons have been widely studied because they allow to provide more
effective, intensive, and adaptive therapies; in addition, they can be used to augment the user’s capabilities
in order to provide movement assistance. In particular, soft robotic exoskeletons have been researched during
the past decade because they allow the device to adapt to the body contours, increasing the user’s comfort.
One of the main challenges in the development of soft robotic exoskeletons is the design of controllers that
allow intuitive and active control of the device. This work addresses the development of a myoelectric Model
Reference Adaptive Controller (MRAC) with an Adaptive Kalman Filter for controlling a cable driven soft elbow
exoskeleton. The proposed MRAC controller proved to be suitable for both passive and active control of the
soft elbow exoskeleton. The controlled system achieved a Mean Absolute Error (MAE) of approximately 4.5° in
passive mode and 10° during active mode. Additionally, the active control mode allowed an average reduction
of 34 % to 40 % in the joint torque RMS when performing dynamic Flexion–Extension movements. The active
control mode is based on a surface electromyography (sEMG) joint torque estimation algorithm that achieved
an approximate MAE of 1 N m. The proposed MRAC controller proved to be robust enough to adapt to the
exoskeleton uncertainties and external disturbances; additionally, the adaptive scheme allowed the system to
operate with only two sEMG channels and the measurement of the joint angle, which is estimated by using
two Inertial Measurement Units.

Abstract del producto

Rehabilitation and assistance exoskeletons have been widely studied because they allow to provide more
effective, intensive, and adaptive therapies; in addition, they can be used to augment the user’s capabilities
in order to provide movement assistance. In particular, soft robotic exoskeletons have been researched during
the past decade because they allow the device to adapt to the body contours, increasing the user’s comfort.
One of the main challenges in the development of soft robotic exoskeletons is the design of controllers that
allow intuitive and active control of the device. This work addresses the development of a myoelectric Model
Reference Adaptive Controller (MRAC) with an Adaptive Kalman Filter for controlling a cable driven soft elbow
exoskeleton. The proposed MRAC controller proved to be suitable for both passive and active control of the
soft elbow exoskeleton. The controlled system achieved a Mean Absolute Error (MAE) of approximately 4.5° in
passive mode and 10° during active mode. Additionally, the active control mode allowed an average reduction
of 34 % to 40 % in the joint torque RMS when performing dynamic Flexion–Extension movements. The active
control mode is based on a surface electromyography (sEMG) joint torque estimation algorithm that achieved
an approximate MAE of 1 N m. The proposed MRAC controller proved to be robust enough to adapt to the
exoskeleton uncertainties and external disturbances; additionally, the adaptive scheme allowed the system to
operate with only two sEMG channels and the measurement of the joint angle, which is estimated by using
two Inertial Measurement Units.

Palabras clave

Myoelectric (EMG) control. Model Reference Adaptive Control (MRAC), Adaptive Kalman Filter, Soft robotics, Elbow exoskeleton