Thermal Model in Feedforward Control of the Gradient Array System in MRI

Resistive elements in a gradient system, namely the gradient coil and the amplifier, causes heating and the total system resistance to increase. With feedforward controllers, such changes cause inaccurate gradient fields to occur, which in turn causes image artifacts. To mitigate self-heating caused resistance change issues, modeling the gradient system's thermal behavior is necessary. Such a model introduces additional parameters to the overall feedforward model, and identifying these parameters correctly is essential for accurate current waveforms. For this purpose, we propose a method to extract these parameters along with a more complete thermal model.