  The stability of standing in humans is a complex process that leads to
maintaining the upright position against external disturbances. Balance control
during standing is of vital importance for humans in daily life. An issue that
is still not clearly understood is which control mechanism the central nervous
system uses to maintain stability. In the rehabilitation of standing function,
the coordination pattern between the angles of the leg joint of a healthy
person should be restored. For example, one of the rehabilitation methods is
functional electrical stimulation. In the work that was mainly done in the
control of standing balance with functional electrical stimulation, the problem
of the optimal pattern using the phase space was not mentioned at all, and a
series of predetermined desired curves were assigned to the joints, and the
controller only used these curves. followed, while the origin of these curves
are not real patterns. Therefore, the main goal of this project is to design a
periodic controller based on phase space. In such a way that a mapping related
to standing is detected first, then a feedback controller is designed so that
it is activated only when the system state space curves find a significant
distance from the detected mapping, then the feedback controller is activated,
and it adjusts the control signal so that the system state space curves come
close to the detected mapping.
