Research Interests

Simulation Substrate for Real-Time Planning


Warning: Page under construction; the following may be gibberish
My research interests were formed by my graduate work in the Experimental Knowledge Systems Laboratory (EKSL) at the University of Massachusetts at Amherst.
EKSL's research includes work on Artificial Intelligence planning, particularly on agents (autonomous entities) acting in an environment. Therefore, our concerns comprise sensing, monitoring and acting as well as classical planning.

We believe in experimental validation of our ideas, and so we have built a number of testbeds, such as Phoenix and TransSim. We have also implemented tools to help define, run, and analyze experiments. These are called CLIP and CLASP, which are described in The CLIP/CLASP Project.

My research is to build a substrate for planning testbeds like Phoenix and TransSim. These testbeds are typical of many planning testbeds, such as (sorry that this is still incomplete):

Truckworld
Truckworld simulates trucks with robot arms that transport goods between cities in a graph. The trucks sense and act by grasping things with their arms. Sensing and acting take time and can fail, requiring robust planning that can deal with uncertainty. For more information, get on the truckworld-users mailing list by sending mail to truckworld-users-request@cs.washington.edu.
MICE
The Michigan Integrated Coordination Experiment is a testbed that simulates agents moving on an abstract gridworld. The testbed allows the user to specify the interactions between agents that occupy the same grid location. The research emphasis is on distributed, cooperative problem solving. For more information, contact ???
Tileworld
Tileworld simulates an agent that pushes tiles around on a grid and receives points for filling holes with tiles. The tiles appear and disappear randomly, thereby putting time-pressure on the agent and making the world uncertain. For more information, contact ??
DVMT
The Distributed Vehicle Monitoring Testbed
Trains
Trains simulates trains moving cargo around in a rail network; it is similar to Truckworld.
One common thread in these testbeds is that they are elaborate and took a great deal of time to implement. One part of my work is to capture the common elements of these simulators in a substrate, so that new domains can be implemented relatively quickly.

Another common thread is that they all define a correspondence between the real-time thinking of the agent and the corresponing amount of time that elapses in the environment. This correspondence supports research in real-time problem solving, since the environment continues while the agent thinks. Many of these testbeds define that correspondence by simply measuring the cpu time of the agent's computation and advancing the clock by a related amount. For example, the default correspondence is Phoenix was 1 cpu second per 5 minutes of simulation time. Other testbeds defined the simulation time taken by particular cognitive actions of the agent and advanced the simulation clock whenever those actions were computed.

I am interested in improving the measurement of real-time thinking in planning testbeds.


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sanderso@wellesley.edu