Oliver Cardwell/Project
Project
This page is under construction ...
Introduction
What is my project all about? Well for my honours project I am looking at the performance of iterative inverse kinematic algorithms. Yes there are a few big words in that title so I will break it down and you will see that its not so bad.
My project focuses on the inverse kinematics of simple joint chains such as a robotic arm or the leg of an computer animated character. If we want to position the end of the robotic arm (end-effector) then we need to tell each joint in the arm to move to a particular angle. Once the robot arm has moved each of its joints to the required position the end-effector will (hopefully) be in the desired position. The hard part of this and coincidently that 'inverse' part of the title is finding out what angles you need at each joint so that the end-effector ends up at the correct location. Enter the CCD algorithm ...
The Cyclic Coordinate Descent (CCD) algorithm is an iterative algorithm that operates on a joint chain and works by converging the end-effector to the desired target location. The CCD algorithm is relativity simple to implement and this makes it very popular for use in the fields of robotics and computer animation and computer games.
Below are to images that will help clarify what the CCD algorithm achieves. The first image is the 'before' shot. The joint chain is stretched out straight with the base of the joint chain at the origin. The green circle is the target location and the red circle is the end-effector of the joint chain. The second image is the 'after' shot. In this second image we can see the result of running the CCD algorithm on the joint chain. You will note that the end-effector has moved to the target location. This is a pretty good indication that everything has gone smoothly in the algorithm, it has been able to find the rotation required for each joint in order hit the target.
 The joint chain before is has moved to the target. |
 The joint chain after is has reached its target. |
Ok so for each target we have a bunch of information regarding the behaviour of the CCD algorithm, these include the number of iterations done to get the end-effector to the target and others such as the total amount of rotation taken by all the joints. If we now use this information to colour the target and we make as many targets as there are pixels then we get a colourised map of performance of the algorithm with the joint chain. The result can be seen below.
Requirements
The requirements for this project are as follows:
