The aim of this paper is to propose
a bipedal structure able to follow high acceleration movements. The
vertical jump of a human has been chosen as input
(coming from experiments) to validate the controller design as it
is one of the most complex motion. The study concerns
the low level of the biped control that is to
say the control design of one leg made of three
rigid bodies, each of them moved by a pneumatic actuator.
An analogy between a pneumatic actuator and a physiological muscle
is first proposed. A dynamic model of the leg is
then presented decoupling the dynamic effects of the skeletal (as
interactions between segments) from the dynamic effects of the muscles
involved. The controller is based on the nonlinear theory (taking
into account the actuator and the mechanical models), it ensures
a dynamic tracking of position and force. Its originality lays
in the consideration of impedance behaviour at each joint during
free and constrained tasks. It leads to asymptotically stable (Popov
criteria) control laws which are continuous between contact and non-contact
phases enabling real-time computations. The simulation results clearly show the
tracking of position and forces during the whole jump cycle.