Abstract: A magnetic actuation system of an interventional surgical robot was studied，which is a new type of

electromagnetic driving device that uses a mobile coil with a ferrous core to realize the magnetic driving in large

space. By using the method of maximizing the magnetic field in the target region，the coil model's geometry was

optimized and solved under the constraints of payload and heat dissipation. A Jacobian inverse matrix was added to

the magnetic field measurement and control loop，and an on-line updating iterative mapping method was used to

generate the required magnetic induction and gradients to drive the catheter motion at given values. Three magnetic field trajectories which are in a spherical workspace with a radius of 1 300 mm were measured by Tesla meters and Hall effect sensors. The minimum intensity of magnetic induction is 20 mT，the maximum is 80 mT，and the gradient is 0.6 mT/mm. The device has a strong novelty and achieves the desired effect.

      Key words: advanced robot；magnetic manipulation system；non-linear actuation；iterative mapping；

optimized design