Unknown Object Large Scale Manipulation based on the Finite State Machine

Introduction:

We propose a simple but efficient control strategy to manipulate objects of unknown shape, weight, and friction properties -- prerequisites which are necessary for classical offline grasping and manipulation methods. With this strategy, the object can be manipulated in hand in a large scale,(eg. to rotate the object 360 degree) regardless whether there is rolling or sliding motion between the fingertips and object. The proposed control strategy employs estimated contact point locations, which can be obtained from modern tactile sensors with good spatial resolution. The feasibility of the strategy is proven in simulation experiments employing a physics engine providing exact contact information. However, to motivate the applicability in real world scenarios, where only coarse and noisy contact information will be available, we also evaluated the performance of the approach when adding artificial noise.

This work based on the previous reactive local manipulation strategy to implement object in hand small scale manipulation. Once the hand joints limitation is detected or predefined rotation action is finished, a static Finite State Machine(FSM) is employed to manage a finger gaits action which makes the hand configuration reach to another proper comfort manipulating posture and new local manipulation can continue.

Static FSM:

Simulation Experiment:

Reference Paper:

• Qiang Li, Martin Meier, Robert Haschke, Helge Ritter and Bram Bolder, "Rotary object dexterous manipulation in hand: a feedback-based method", Int. J. Mechatronics and Automation, Vol. 3, No. 1, 2013