1
INTRODUCTION
6
Many people use the Toolbox for teaching and this is something that I would encourage.
If you plan to duplicate the documentation for class use then every copy must include the
front page.
If you want to cite the Toolbox please use
@ARTICLE{Corke96b,
AUTHOR
= {P.I. Corke},
JOURNAL
= {IEEE Robotics and Automation Magazine},
MONTH
= mar,
NUMBER
= {1},
PAGES
= {24-32},
TITLE
= {A Robotics Toolbox for {MATLAB}},
VOLUME
= {3},
YEAR
= {1996}
}
which is also given in electronic form in the README file.
1.8
A note on kinematic conventions
Many people are not aware that there are two quite different forms of Denavit-Hartenberg
representation for serial-link manipulator kinematics:
1. Classical as per the original 1955 paper of Denavit and Hartenberg, and used in text-
books such as by Paul[1], Fu etal[2], or Spong and Vidyasagar[3].
2. Modified form as introduced by Craig[4] in his text book.
Both notations represent a joint as 2 translations (A and D) and 2 rotation angles (
and
).
However the expressions for the link transform matrices are quite different. In short, you
must know which kinematic convention your Denavit-Hartenberg parameters conform to.
Unfortunately many sources in the literature do not specify this crucial piece of information.
Most textbooks cover only one and do not even allude to the existence of the other. These
issues are discussed further in Section 3.
The Toolbox has full support for both the classical and modified conventions.
1.9
Creating a new robot definition
Let's take a simple example like the two-link planar manipulator from Spong & Vidyasagar[3]
(Figure 3-6, p73) which has the following (standard) Denavit-Hartenberg link parameters
Link
a
i
i
d
i
i
1
1
0
0
1
2
1
0
0
2
where we have set the link lengths to 1. Now we can create a pair of link objects: