Embedded Non-linear Position Control of an Electromagnetic Actuator

Jorge Perez

University of Freiburg

Wednesday, June 28, 2017, 10:00

"Room 01-012, Georges-Köhler-Allee 102, Freiburg 79110, Germany"

The present master's thesis deals with the implementation of a model-based embedded position control method for an electromagnetic actuator. The structure of this control system is composed of two cascaded controllers, where the inner loop is controlled by a PI controller for the coil current, while the outer loop is controlled by a flatness-based position controller. Since the position control requires system states which are not measured, a state estimation is made through the use of a Luenberger observer as well as a Kalman filter. The control system is implemented on a Xilinx Zynq 7000 Evaluation Board for the ZC702 SoC, a device that combines an ARM Cortex-A9 Processing System with a 28 nm Xilinx Programmable Logic. In order to be able to implement this control system, a developmed framework is created based on Xilinx Vivado and the Embedded and HDL Coders for Matlab/Simulink. This framework allows the implementation of embedded control methods by defining Matlab scripts or Simulink models. Furthermore, the framework can be reused with minimal changes for the implementation of different control methods.
In this work it is shown that the embedded implementation of a flatness-based trajectory tracking control with soft-landing is feasible. The interactive nature of Simulink allows the user to modify system parameters such as controller gains in real-time. Furthermore, the analysis of signal transients such as the current ripple due to the current controller's PWM signal is made possible through the use of a FIFO buffer, which records data at a high sampling rate, and then delivers it to the Simulink interface at a slower rate.