Trajectory (Interface Manipulation Package)

[using it]

Interface Manipulation Package v4.0 (2008-06-25)

©copyright

imp.trajectory
Class Trajectory

java.lang.Object
  imp.trajectory.Trajectory

public class Trajectory
extends Object
extends Object

Defines a trajectory generator.

Formally this is defined as going from an initial state defined by a numerical value vector x_o to a final state (i.e. a goal) x_oo considering constraints or obstacles to be avoided.

Very easily a user:

add/delete obstacles / constraints.
setEnd i.e. set (one of) the final state / goal / end point of the trajectory.

get the trajectory by iteratively computing the next state, given a current state. For instance the piece of code:

  Vector getTrajectory(double x0[]) {
    Vector trajectory = new Vector(); trajectory.add(x0); double x1[] = x0;
    do { x0 = x1; trajectory.add(x1 = get(x1)); } while(x0 != x1);
    if (!trajectory.isAtEnd(x1)) throw new IllegalStateException("Trajectory generation fails");
    return trajectory;
  }

returns the whole trajectory, given an initial state x0[].

Nested Class Summary
`static class`	`Trajectory.Constraint` Defines an obstacle from an equation: `c(x) > 0` for `x` outside the obstacle.
`static class`	`Trajectory.Obstacle` Defines a trajectory obstacle.

Constructor Summary
`Trajectory(int dim, double step)` Constructs a trajectory.

Method Summary
`Trajectory`	`add(Trajectory.Obstacle obstacle)` Adds an obstacle for the trajectory and return this.
`double[]`	`get(double[] x0)` Returns the point next to x0[] for this trajectory or x0[] if on the goal or if it fails.
`boolean`	`isAtEnd(double[] x0)` Test if the trajectory point reaches the goal
`Trajectory`	`remove(Trajectory.Obstacle obstacle)` Deletes an obstacle for the trajectory and return this.
`Trajectory`	`setEnd(double[] x_oo, boolean goal)` Defines the goal, i.e.

Methods inherited from class java.lang.Object
`equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

Trajectory

public Trajectory(int dim,
                  double step)

Constructs a trajectory.

Parameters:: dim - Problem dimension; step - Minimal distance between two distinguishable points.

Method Detail

add

public Trajectory add(Trajectory.Obstacle obstacle)

Adds an obstacle for the trajectory and return this.

get

public double[] get(double[] x0)

Returns the point next to x0[] for this trajectory or x0[] if on the goal or if it fails.

isAtEnd

public boolean isAtEnd(double[] x0)

Test if the trajectory point reaches the goal

remove

public Trajectory remove(Trajectory.Obstacle obstacle)

Deletes an obstacle for the trajectory and return this.

setEnd

public Trajectory setEnd(double[] x_oo,
                         boolean goal)

Defines the goal, i.e. the end/final point and return this

Parameters:: x_oo - End point coordinates; goal - [optional, default is true] If true this is the final goal and the trajectory ends, else it is an intermediate temporary goal.

imp.trajectory Class Trajectory

Trajectory

add

get

isAtEnd

remove

setEnd

imp.trajectory
Class Trajectory