Towards environment-aware constrained-based manipulation for service robots

By R.W.J. Wijnands

Background

Literature

Whole-body Control

A constraint on the right gripper

Include a world model

World modeling

By using occupancy grid mapping

Object-oriented world model

Comparison

Multiple types of constraints in the skill layer

Grasping skill

Partial constraints

Grasp skill definition

New constraint types

1. partial constraints
2. simultaneous constraints
3. dynamic constraints

World model connection

Requirements

• Multiple geometry types

  1. primitive shape (box, sphere, capsule, cone, cylinder, plane)

  2. polygon mesh

  3. octree

• Non blocking

• Handles large world models

world model revisions

world model revisions

World model connection

Touching objects

Experiments

Experiment 1

Grasping

Experiment 2

Collision avoidance

Experiment 2

Results

Experiment 2

More results

"Sticking issue"

Discontinous control output

Conclusions

• partial, simultaneous and dynamic constraints
  • grasping skill parameters reduced from 16 to 4
  • grasping time decreased from 3 to 2 minutes
• integrate an object-oriented world model
  • successful environment collision avoidance
  • distinguish objects that can be touched from the rest
  • grasp moving objects without re-planning

Recommendations

• "sticking issue" & discontinuous control output
  • A. Dietrich et al. (2012) On continuous null space projections for torque-based, hierarchical, multi-objective manipulation
• additional testing systems
  • 1 DOF force feedback loop
  • planar 3-link system