University of Twente Student Theses


Multi-Point Orientation Control of Discretely Magnetized Continuum Manipulators

Richter, Michiel (2020) Multi-Point Orientation Control of Discretely Magnetized Continuum Manipulators.

[img] PDF
Abstract:In the past decade, remote actuation through magnetic fields has been used for position and orientation control of continuum manipulators (CMs). Complex manipulator shapes can be achieved by leveraging multiple points of actuation along the length of the CM. In this thesis we present an approach for multi-point orientation control of discretely magnetized CMs based on a quasi-static forward model. The manipulator contains two permanent magnets, which are each actuated by unique and independent magnetic fields generated by an array of mobile electromagnets. We formulate an accurate model to represent the magnetic field and field gradient of an azimuthally symmetric electromagnet based on a multipole expansion of a Cartesian scalar potential. This description is applied to predict exerted wrenches on the continuum manipulator. Cosserat rod theory is used to model the manipulator deformation under external wrenches. A numerically-computed Jacobian is developed to calculate the actuation inputs. A stereo vision setup is used to reconstruct the shape of the CM. During experiments, manual steps in target orientations are given to show independent orientation control of the two permanent magnets in 2D. Multi-point orientation control in 3D is demonstrated through a virtual clone of an electromagnetic system with movable electromagnets. In both scenarios, it is observed that the algorithm is able to successfully steer two magnets in a non-uniform magnetic field.
Item Type:Essay (Master)
Faculty:ET: Engineering Technology
Programme:Biomedical Engineering MSc (66226)
Link to this item:
Export this item as:BibTeX
HTML Citation
Reference Manager


Repository Staff Only: item control page