Velocity Analysis
Jacobian
Stanford Manipulator
University of Bridgeport
1
ROBOTICS
Kinematic relations
6
5
4
3
2
1
z
y
x
X
Joint Space
Task Space
θ =IK(X)
Location of the tool can be specified using a joint space or a cartesian space
description
X=FK(θ)
Velocity relations
Joint Space
Task Space
•Relation between joint velocity and cartesian
velocity.
•JACOBIAN matrix J(θ)
6
5
4
3
2
1
z
y
x
z
y
x
)(JX XJ
)(
1
Jacobian
•Suppose a position and orientation vector of a
manipulator is a function of 6 joint variables: (from
forward kinematics)
X = h(q)
z
y
x
X 16
6
5
4
3
2
1
)(
q
q
q
q
q
q
h 166216
6215
6214
6213
6212
6211
),,,(
),,,(
),,,(
),,,(
),,,(
),,,(
qqqh
qqqh
qqqh
qqqh
qqqh
qqqh
Jacobian Matrix
•If
•Then the cross product,
xx
yy
zz
ab
A a B b
ab
()
y z z y
x y z x z z x
x y z x y y x
i j k a b a b
A B a a a a b a b
b b b a b a b
Remember DH parmeter
•The transformation matrix Ti i i i i i i
i i i i i i i
i i i
c -c s s s a c
s c c -s c a s
0 s c d
0 0 0 1
i
A
i
i
AAAT .....
210
Stanford Manipulator i i i i i i i
i i i i i i i
i i i
c -c s s s a c
s c c -s c a s
0 s c d
0 0 0 1
i
A
The DH parameters are:
Stanford Manipulator 1
01
TA 1 2 1 1 2 2 1
1 2 1 1 2 2 12
0 1 2
22
00
0 0 0 1
c c s c s d s
s c c s s d c
T A A
sc
0
0
0
1
z
1
11
0
s
zc
12
2 1 2
2
cs
z s s
c
1 2 1 1 2 3 1 2 2 1
1 2 1 1 2 3 1 2 2 13
0 1 2 3
2 2 3 2
0
0 0 0 1
c c s c s d c s d s
s c c s s d s s d c
T A A A
s c d c
12
3 1 2
2
cs
z s s
c
3 1 2 2 1
3 3 1 2 2 1
32
d c s d s
O d s s d c
dc
01
0
0
0
OO
21
2 2 1
0
ds
O d c
Stanford Manipulator 4
0 1 2 3 4
T A A A A 5
0 1 2 3 4 5
T A A A A A 6
0 1 2 3 4 5 6
T A A A A A A 1 2 4 1 4
4 1 2 4 1 4
24
c c s s c
z s c s c c
ss
T4 =
[ c1c2c4-s1s4, -c1s2, -c1c2s4-s1*c4, c1s2d3-sin1d2]
[ s1c2c4+c1s4, -s1s2, -s1c2s4+c1c4, s1s2d3+c1*d2]
[-s2c4, -c2, s2s4, c2*d3]
[ 0, 0, 0, 1]3 1 2 2 1
4 3 1 2 2 1
32
d c s d s
O d s s d c
dc
Stanford Manipulator
T5 =
[ (c1c2c4-s1s4)c5-c1s2s5, c1c2s4+s1c4, (c1c2c4-s1s4)s5+c1s2c5,
c1s2d3-s1d2]
[ (s1c2c4+c1s4)c5-s1s2s5, s1c2s4-c1c4, (s1c2c4+c1s4)s5+s1s2c5,
s1s2d3+c1d2]
[ -s2c4c5-c2s5, -s2s4, -s2c4s5+c2c5, c2d3]
[ 0, 0, 0, 1]1 2 4 5 1 4 5 1 2 5
5 1 2 4 5 1 4 5 1 2 5
2 4 5 2 5
c c c s s s s c s c
z s c c s c s s s s c
s c s c c
1 2 4 5 1 4 5 1 2 5
5 1 2 4 5 1 4 5 1 2 5
2 4 5 2 5
c c c s s s s c s c
z s c c s c s s s s c
s c s c c
Stanford Manipulator
T5 =
[ (c1c2c4-s1s4)c5-c1s2s5, c1c2s4+s1c4, (c1c2c4-s1s4)s5+c1s2c5,
c1s2d3-s1d2]
[ (s1c2c4+c1s4)c5-s1s2s5, s1c2s4-c1c4, (s1c2c4+c1s4)s5+s1s2c5,
s1s2d3+c1d2]
[ -s2c4c5-c2s5, -s2s4, -s2c4s5+c2c5, c2d3]
[ 0, 0, 0, 1]1 2 4 5 1 4 5 1 2 5
5 1 2 4 5 1 4 5 1 2 5
2 4 5 2 5
c c c s s s s c s c
z s c c s c s s s s c
s c s c c
3 1 2 2 1
5 3 1 2 2 1
32
d c s d s
O d s s d c
dc