Research Topics Dr. Ming Liu

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Research Topics Dr. Ming Liu

• Force control
• Non-linear control systems
• Decentralised control
• Dynamic vision
• Real-time image processing

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Force Control
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Applications

• Surgery robots
• Master-slave systems
• Remote controlled surgery robots
• Painting, Deburring and Grinding
• Assembling

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• Control the motion and contacting force of a
  robot manipulator while it keeps moving and
  contacting with the environment.
• Ensure the smooth transition from free motion
  control to constrained motion/force control.
• Collision dynamics needs to be carefully studies.
• Nonlinear frictions become dominant.

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Force control scheme by N. H.
Quach and M. Liu

• Based on the investigation on the transit
  dynamics from free motion to restrained
  motion/force control some effective control
  schemes have been proposed which
• ensures the smooth transition and asymptotic
  stability.
• takes the complicated friction dynamics into
  account.

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Simulation results

• Task defined

robot tip trajectory defined
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Work space trajectory planning
robot arm
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Position trajectories in joint space
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Velocities in joint space
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Joint velocity in work space
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Reference trajectories in work space
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Collision Phase - from free motion mode to
constrained force/motion mode
ref trajectory
environment surface
real trajectory
?x
force applied to the surface k?x
collision point