The Calibration of a Parallel Manipulator with Binary Actuation

This paper investigates how parameter identification can improve the calibration of elastically averaged parallel manipulators. The method developed is applied to a needle manipulator for intra-Magnetic Resonance Imaging (MRI) prostate cancer treatment. The device uses MRI-compatible Dielectric Elastomer Actuators to precisely guide a needle during its insertion for taking biopsy or implanting radioactive seeds in the prostate. Here, an analytical model of the device is presented and a sensitivity analysis identifies the key model parameters. Parameter identification is conducted with an optimization algorithm. The method is tested on both simulated parameter values and experimental data. The results show that the method can improve the device accuracy by at least one order of magnitude (on simulated parameters).