To gain greater adaptivity in natural terrain conditions,
animals are observed to regularly jump over
large obstacles.
At the Ohio State University, dynamic control
of two types of jumps have been developed for a quadruped.
They are the standing jump and the running jump.
The model used in the development
has a size and weight similar to that of a large dog.
It uses simple telescoping and springy legs.
The terrain shown is divided into a half meter
by half meter grid.
Here, a quadruped is shown jumping over a wall
with a height of about 1 meter.
The motion traces of the body and the feet
are also displayed.
During takeoff, the front and the back legs
are coordinated to impart appropriate amounts
of linear and angular momentum to the body.
While in flight, leg motions are planned
to maximize clearance and prepare for landing.
Note the ballistic motion for the system.
During landing, the front legs and the back legs in turn
remove all the linear and angular momentum of the body.
Adaptation to terrain-level variation
is shown here where the landing and the takeoff levels
are different.
In order to achieve a greater span, the running jump is used.
As it is shown approaching a ditch,
the quadruped is running at 4 meters
per second in a bounding gait.
Unlike the standing jump, at no time
are the front and the back legs on the ground simultaneously.
During the transition from a bounding gait to a jump,
the quadruped applies the appropriate amounts
of linear and angular momentum to the body
to give a desired jumping height and span.
The jump is then characterized by an extended flight phase.
Unlike a standing jump, part of the energy during landing
is reused for transition back into a bounding gait.
A number of bounding cycles are needed
to regain the original running speed.
A variety of terrain conditions with different takeoff
and landing levels have also been tested,
including that of a terrain step, shown here.
With further refinements to the jumping algorithms,
application may be found in high-speed locomotion
over irregular terrain.