Seite - 214 - in Proceedings - OAGM & ARW Joint Workshop 2016 on "Computer Vision and Robotics“
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with themodifiedoptimizationproblem{
‖c‖=‖c1‖+‖c2‖→min
c1= (
A˜ T
1 )+(
y˜− A˜T2c2 ) }
. (23)
Thesolutionstructure is equivalent to
c= (
A˜ T
(q) )+(
M˜(q)q¨+ C˜(q, q˙) q˙+Q˜(q, q˙) )
︸ ︷︷ ︸
1 +N
A˜ T
(q)c0︸
︷︷ ︸
3 , (24)
withN
A˜ T = Im−(A˜T) +
A˜ T
, butunlikebefore
(
A˜ T )+
=
(
A˜ T
1 )+(
In− A˜T2 (
Im−δ+BTB
)−1BT(A˜T1)+)(
Im−δ+BTB
)−1BT(A˜T1)+
, B=(A˜T1)+A˜T2 (25)
isnot the rightpseudoinverse.
4.2. AugmentedPDController
Thesolutionof the inversedynamics isonlyacontrol schemewithout thefeedback termbyweighted
joint errors. Therefore, sucha termhas tobeadded toEq. 20
c= (
AT (q) )+
W (
M(q) q¨di+C(q, q˙)q˙ d
i+Q(q, q˙)
)︸
︷︷ ︸
1 −(AT
(q))+W(KPei+KDe˙i)︸
︷︷ ︸
2 +NAT,W(q)c
0︸
︷︷ ︸
3 ,
(26)
for thecontrol torques inminimal formulationand
c= (
A˜ T
(q) )+(
M˜(q) q¨d+ C˜(q, q˙)q˙d+Q˜(q, q˙) )
︸ ︷︷ ︸
1 − (
A˜ T
(q)
)+(
K˜Pe+K˜De˙
)
︸ ︷︷ ︸
2 +N
A˜ T
(q)c0︸
︷︷ ︸
3 .
(27)
for the redundant formulation (Eq. 24). The superscriptd indicates thedesiredvalues. Thevariables
ei=qi−qdi , respectivelye=q−qd are theerrorcoordinatesandKP,KD,K˜P,K˜D are theweighting
matrices for thePDcontroller.
4.3. SimulationResults
The simulations are realizedwith an augmented PD controller in both formulations. Furthermore,
quantization effects of encoders are implemented. Theweightingmatrices of the PDcontroller are
chosenby two issues. Firstly, the joint error shall be as small as possible. And secondly, the torque
of themotors shallnotbe toohighandaggressive.
Thepath is a simplepoint topointmotionwitha fewarbitrarypointsand theacceleration is realized
by sin2profiles.
Furthermore, the unknowndynamics parameters are foundwith aCADprogram. Table 1 shows an
overview.J is themass inertiaaroundtheCoGandrelevantaxis,except theentryof theMotor/active
link - combination. Instead it is along themotor axis.m is themass and ls is the distance between
214
Proceedings
OAGM & ARW Joint Workshop 2016 on "Computer Vision and Robotics“
- Titel
- Proceedings
- Untertitel
- OAGM & ARW Joint Workshop 2016 on "Computer Vision and Robotics“
- Autoren
- Peter M. Roth
- Kurt Niel
- Verlag
- Verlag der Technischen Universität Graz
- Ort
- Wels
- Datum
- 2017
- Sprache
- englisch
- Lizenz
- CC BY 4.0
- ISBN
- 978-3-85125-527-0
- Abmessungen
- 21.0 x 29.7 cm
- Seiten
- 248
- Schlagwörter
- Tagungsband
- Kategorien
- International
- Tagungsbände