ATTRIBUTE DESCRIPTION SET) ?
The READ set captures all of the objects in the environment that the robots will interact with. But just listing the objects in the environment does not give us the complete picture of what we're up against. Not all environments are created equal. Some environments are dynamic, changing at the very time the robot(s) are trying to accomplish a task. Objects within the environments are sometimes affected by forces other than the robots. Some environments are either partially, fully, or not accessible to a robot. If all the objects in the environment are within the reach of the robot's sensors and actuators then the environment is said to be fully accessible. If the robot's sensors or actuators can only interact with some things in the environment, then the environment is partially accessible. For instance, an environment may contain sounds and objects. The robots may be able to interact with the objects, but have no sensors that can detect sound. In that case the environment is partially accessible. The environment may be deterministic. That is, the environment is accessible, and the only time it changes is when the robot changes it. There are no outside forces interacting on any of the objects. Whatever the state the robot puts the environment in, that's the state the environment will stay in until the robot makes another change. Because not all environments are created equal, we must not only be concerned with the objects in the environment, but with the nature of the environment as well. The table contains the basic classifications of environments.
Every environment is a little different and each environment has its own set of challenges. It's been our experience that you cannot realistically separate building and designing your robots from a thorough understanding of it's environment. The environment that the team works in will determine how they can or cannot work together. The fact that there are several types of environments mean that any planning of team coordination has to be deferred until the class of the environment and READ set are understood. Putting together a team of robots to accomplish a given goal will be dictated by the environment classification, the robot's Read set, and the Capability Matrix.
Above is the LEGO MINDSTORMS Robot World (Test Bed). This can be considered a READ SET for a LEGO ROBOT. The table is the text description of the READ SET.
During the initial testing of many NXT Mindstorms robots, this test pad is the robot's world/environment. If we set the robots start position on one of corners of the test pad and program it to search for a blue square, the robot has no more than 720 square inches to search depending on which corner is set as the robot's starting point.
The blue square is either in the robot's environment or not. Since we stated that this was a 2-dimensional environment, the robot only has to search along its X axis or Y axis for the blue square. We assume a value of 0 for the the Z axis. Notice that we did not mention anything about the robot's capabilities. We only gave the physical description of the robot's environment and the task to be executed. The robot designer will have to come up with a design that will meet this challenge.
So from this we see that the environment and the problem alone can dictate many aspects of the robot's design. Clearly in this case the robot needs to be mobile and have some type of visual sensing, a camera, light sensor, IR sensors, etc. Also the 720 square inches says something about the size of the robot that we are building. A robot that has a base of 1500 square inches would immediate violate the environmental constraints. So the fact of the matter is, if we don't have a detailed model or view of the robot's environment and nature of the problem then it will be very hard for us to build the robots needed. In fact, the robot's target environment and the nature of the tasks that it will be expected to perform have to be if not the 1rst question to be answered, certainly among the top 2 or 3.
This is a READ SET for an example from the book. Some of the important features of this read set is that it is 5ft by 6ft in size. It's a rectangular area. There will be three glass 9 cm tall beakers with a diameter of 7/12 cm. The beakers are going to be placed 18 inches apart on the left edge of the environment. W (waypoints) 1-3 are the start locations, W4 is where a chemical analysis will be performed. W5-7 are the ending locations for the beakers. We can see the placement where the robots would be in the environment. Below is a side view of the read set. The side view is important because it gives you the relative heights and lengths of all of the objects that the robots have to deal with in proportion to the heights of the robots.
Looking at the Read Set top view, side view, and the basic goal of the robots, we decided which robots we will use for the project. Once the decision is made on which robots to use, we then have to come up with a plan or strategy that will actually result in the robots accomplishing the task at hand.
TECHNIQUE: GRIOT ARCHITECTURE
DEVELOPED BY: CTEST LABS
YEAR FIRST PUBLISHER: 1998
SUMMARY:
Rational distributed multi-agent design;
Methods to construct multi-agent systems
that perform group reasoning.