Robot Sheepdog Project
The original project (1996-1998)
People have been building robotic systems that work with humans for
many years, and they generally assume that the humans are cooperative;
but what about robots to work with animals? It was this thought that
led to the "Robot Sheepdog Project" (RSP) at the Silsoe Research
Institute, which brought together 3 research students based in Oxford,
Leeds and Bristol, together with Silsoe's experience at dealing with
In fact, it was soon decided that herding sheep was too big
a jump in one step, and so the robot herds ducks instead -- but as
these are used to train sheepdogs we claim that the results could be
applied to sheep! The robot uses a fixed television camera to see what
the ducks are doing, and our student takes this information, plus a
mathematical model of the ducks' behaviour, and uses this to
control the robot.
This may sound straightforward, but nothing like it has ever been tried
before; we had to design the robot, guess the correct mathematical
model, and implement it whilst ensuring that the ducks were never
harmed! To do this we first relied a lot on simulation, and on seeing
whether the mathematical model gave simulated results that "looked
right" to expert duck herders. Finally, the system was tried with real
ducks, and was shown to be capable of herding a flock of ducks from one
end of an arena to a specified position at the other end.
Robot Sheepdog Project achieves automatic flock control, in
Proceedings of the International Conference on
Simulation of Adaptive Behaviour, Zurich, Switzerland (1998).
Robot control of animal flocks, in
Proceedings of the International Symposium on
Intelligent Control, Gaithersburg, Maryland, USA (1998).
- Experiments in Automatic Flock Control,
Journal of Robotics and Autonomous Systems 31:109-117, April 2000,
© Elsevier Science BV.
The current project
The Spatial Reasoning research group is continuing the research work,
but using robot sheep as well as robot sheepdogs to extend the theories
without the complications of dealing with real animals.
The project uses a collection of small wheeled mobile robots, each of
which can act as a sheep or a dog. The "sheep" behave according to a
pre-programmed flocking model, whereas the "dogs" are controlled
through an external PC. The dogs can be driven by a human using a
joystick, or can be programmed to herd the sheep to a predetermined
The projects objectives are
- to develop a scientific understanding of the way in which flocking
and herding behaviour in animals occurs;
- to investigate how collaboration between robots allows them to
perform tasks that they could not perform alone;
- to investigate the scientific feasibility of robot "guard dogs".
The system uses an overhead camera that tells a central computer where
each animal is. Thus the controller knows about all the animals, but
the robots can be kept simple and cheap as they contain few processing
or sensing mechanisms. The PC sends low-level commands to the robots
via infra-red links.
The model of sheep and duck behaviour is very simple and contains just three
terms: attraction to one another, repulsion from walls and other fixed
obstacles, repulsion from the dog. Although the model contains only these
three terms, plus a random "jitter", there is a realistic tendency for
the robotic sheep and ducks to flock.
To move the flock in a particular direction, an individual sheepdog has
to move until the flock is between itself and the goal, then gently move
forward until the animals are at the goal, and finally back away.
For all the animals, it is interesting to see complex emergent
behaviour develop from these simple components. The simplicity of the
models which can show realistic behaviour suggests that certain sorts
of animal (and human?) behaviour can be quite simply analysed, and
raises the possibility that an analysis of human behaviour could, for
example, be used to design safer sports stadia.