Stiffness Control of a Parallel Robot with Oppositional Operating Dimitar Chakarov Institute of Mechanics, BAS, Acad.G.Bonchev Street, Block 4, Sofia, Bulgaria, E-mail: [e-mail]

1
Stiffness Control of a Parallel Robot with
Oppositional Operating Dimitar
ChakarovInstitute of Mechanics, BAS,
Acad.G.Bonchev Street, Block 4, Sofia, Bulgaria,
E-mail mit_at_imbm.bas.bg

• .

• 1.Introduction
• 2.Stiffness control schemes realized by means of
  redundant actuation
• 3.Stiffness Control of a Serial Parallel
  Manipulator with Actuation Redundancy
• 4.Ellipsoid of the Linear Compliance
• 5.Approaches of Compliance Numerical
  Specification
• 6.Simulations
• 7.Control scheme
• 8.Conclusion

2

• 2.Stiffness control schemes realized by means of
  redundant actuation
  
• 2.1.Passive stiffness control
• 2.2.Feedback Stiffness Control

• 2.2.1.Direct compliance control (DCC)K.Yokoi,
  M.Kaneko,K.Tanie

h2m3
3

• 2.3.Antagonistic Actuation Stiffness Control

2.3.1.Open loop stiffness control.B.-Ji Yi,R.
Freeman, D.Tesar
h3m9-12
4
2.3.2.Lower bound stiffness control.S.Kock,
W.Schumacher
h2m3
5
2.3.3. Stiffness control with utilize the
internal forces to modulate the stiffness at
variable contact location.M.Adli, K.Ito,
H.Hanafusa
h3m4
6
(No Transcript)
7
4. Ellipsoid of the Linear Compliance

• matrix of linear compliance
• unit vector of the force
• equation of the ellipsoid of the linear
  compliance

8
5. Approaches of Compliance Numerical
Specification and Manipulator Control

• A. Specification of the upper compliance bounds
  in the operation space (if b1
  gt b2 gt b3 then bmax b1 )

• B. Specification of the compliance along a given
  direction in the operation space.

9
6. Simulations6.1. A. Guaranteeing the upper
bounds bo of the main compliances in all
directions for m3,4,5,6 actuators.
Optimal values of the actuating forces for
compliance upper bound b0 0.005 m/N.
Compliance ellipses for cases 1,2,3,4
10
6.2. B. Guaranteeing the compliance upper bound
b0 0.005 N/m along a different direction
a30,60,90,120,150,180 for m6 actuators.
Optimal values of the actuating forces,
regarding different directions ?.
Compliance ellipses for cases 6,7,8,9,10,11.
11
6.3. A. Guaranteeing the upper bounds b0 0.005
N/m of the main compliances in all directions
in the motion trajectory points A1,A2,A3, A4, A5
for m6 actuators.
Optimal values of the actuating forces, in the
motion trajectory points.
Compliance ellipses in the points A1,A2,A3,A4, A5
corresponding to the forces.
12
6.4. B. Guaranteeing the compliance upper bound
b0 0.005 N/m along a single direction a150
in the motion trajectory points A1,A2,A3, A4, A5
for m6 actuators.
Optimal values of the actuating forces, in the
motion trajectory points.
Compliance ellipses in the points A1,A2,A3,A4, A5
corresponding to the forces.
13
7. Stiffness control scheme of a parallel
manipulator