robot
54
functions:
offset
,
qlim
,
islimit
.
The offset vector is added to the user specified joint angles before any kinematic or dynamic function is
invoked (it is actually implemented within the link object). Similarly it is subtracted after an operation
such as inverse kinematics. The need for a joint offset vector arises because of the constraints of
the Denavit-Hartenberg (or modified Denavit-Hartenberg) notation. The pose of the robot with zero
joint angles is frequently some rather unusual (or even unachievable) pose. The joint coordinate offset
provides a means to make an arbitrary pose correspond to the zero joint angle case.
Default values for robot parameters are:
robot.name
'noname'
robot.manuf
"
robot.comment
"
robot.gravity
[0 0 9.81] m/s
2
robot.offset
ones(n,1)
robot.base
eye(4,4)
robot.tool
eye(4,4)
robot.lineopt
'Color', 'black', 'Linewidth', 4
robot.shadowopt
'Color', 'black', 'Linewidth', 1
The multiplication operator,
*
, is overloaded and the product of two robot objects is a robot which is
the series connection of the multiplicands. Tool transforms of all but the last robot are ignored, base
transform of all but the first robot are ignored.
The
plot
function is also overloaded and is used to provide a robot animation.
Examples
>> L{1} = link([ pi/2
0
0
0])
L =
[1x1 link]
>> L{2} = link([ 0
0 0.5 0])
L =
[1x1 link]
[1x1 link]
>> r = robot(L)
r =
(2 axis, RR)
grav = [0.00 0.00 9.81]
standard D&H parameters
alpha
A
theta
D
R/P
1.570796
0.000000
0.000000
0.000000
R
(std)
0.000000
0.000000
0.500000
0.000000
R
(std)
Robotics Toolbox Release 8
Peter Corke, December 2008