i_fsa_ba.java

利用JAVA编写的群体机器人局部通讯完成一定得队形控制

/*
 * i_FSA_ba.java
 */

package EDU.gatech.cc.is.clay;

import java.lang.*;

/**
 * A Finite State Automoton that generates an integer output.  
 * While in the current state, if trigger[current_state][edge].Value() 
 * is true, the new state is follow_on[current_state][edge].
 * You must fill in the values of these arrays yourself.  It is
 * best to look at an example.
 * <P>
 * This node may be used to implement "Temporal Sequencing" as
 * developed in the Mobile Robot Lab at Georgia Tech.
 * <P>
 * The source code in this module is based on "first principles"
 * (e.g. published papers) and is not derived from any previously
 * existing software.
 * <P>
 * For detailed information on how to configure behaviors, see the
 * <A HREF="../clay/docs/index.html">Clay page</A>.
 * <P>
 * <A HREF="../COPYRIGHT.html">Copyright</A>
 * (c)1997, 1998 Tucker Balch
 *
 * @author Tucker Balch
 * @version $Revision: 1.1 $
 */


public class i_FSA_ba extends NodeInt
	{
	private	long	lasttime = -1;
	private	int	lastval;
	private int	count=0;

	/**
	Maximum number of states.
	*/
	public static final int MAX_STATES = 50;

	/**
	The initial state.  Default is 0.
	*/
	public	int	state = 0;

	/**
	The triggers that lead to new states.  Indexed as follows:
	trigger[current_state][edge].
	*/
	public	NodeScalar[][] triggers = new NodeScalar[MAX_STATES][MAX_STATES];

	/**
	The follow on states that triggers lead to.  Indexed as follows:
	follow_on[current_state][edge]
	*/
	public	int[][] follow_on = new int[MAX_STATES][MAX_STATES];

	/**
	Instantiate an FSA.  Configuration is by setting
	trigger and follow_on arrays.
	*/
	public i_FSA_ba()
		{
		}
	
	/**
	Get the value of the node.
	
	@param timestamp long, the time of the request.
	*/
	public int Value(long timestamp)
		{
		if ((timestamp != lasttime)||(timestamp == -1))
			{
			if (timestamp != -1) lasttime = timestamp;
			int i = 0;
			while(triggers[state][i] != null)
				{	
				if (triggers[state][i].booleanValue(timestamp) == true)
					{
					state = follow_on[state][i];
					break;
					}
				i++;
				}
			}
		return state;
		}
	}