James Kuffner  
 
Research
Papers

Simulation Snapshots and Movies

Planar Translating Body (state space dimension = 4)

The first experiment considered a rigid object with a set of translational controls that restrict its motion to a plane.  A total of 4 controls were used, consisting of a set of two pairs of opposing forces acting through the center of mass of the body.  Typically, anywhere between 500 and 2500 nodes are explored before a solution trajectory is found, with a total computation time ranging between 5 and 15 seconds on a 200 MHz SGI Indigo2 running Irix 6.2.

Example state exploration trees computed for a
rigid rectangular object (left). The goal location
is represented by a sphere (upper right).

 
This series of images shows various stages of the state exploration during planning.  The total number of nodes contained in the two RRTs is shown below the images.
 

500 nodes 1000 nodes 1582 nodes trajectory
500 nodes 1000 nodes 1582 nodes final trajectory

Here are some sample movies depicting a different run of the planner in the same environment. The first movie depicts the growth of the RRTs during the planning process. The second movie illustrates the execution of the computed solution trajectory.

 


 

Planar Body with Rotation (state space dimension = 6)

These images illustrate the RRTs and final trajectory computed for a rigid body (spaceship) with unilateral thrusters (it can rotate freely, but can accelerate only in the forward direction). As in the previous case, the available controls restrict its motion to a plane.

RRTs trajectory
state exploration RRTs final trajectory

 

Translating 3D Body (state space dimension = 6)

These images illustrate the RRTs and final trajectory computed for a translating 3D rigid body. It has three pairs of opposing thruster controls along its principal axes. This allows it to translate freely, but not rotate. The task is to navigate through a sequence of narrow passages and obstacles.

RRTs trajectory
state exploration RRTs final trajectory

Here are some sample movies depicting the same rigid model in a different obstacle-cluttered 3D environment. The first movie depicts the growth of the RRTs during the planning process. The second movie illustrates the execution of the computed solution trajectory.

 

3D Body with Full Translation and Rotation (state space dimension = 12)

These images illustrate the RRTs and final trajectory computed for a translating, fully-orientable 3D rigid body (satellite). It has three pairs of opposing rotational thruster controls, allowing it to be oriented arbitrarily. In addition, it has a pair of opposing thrusters that allow it to translate along its long axis. The task is to navigate through the cloud of obstacles and "dock" in the shuttle cargo bay.

RRTs trajectory
state exploration RRTs final trajectory


1997 - 2009 © James Kuffner, Jr.