A self tuning regulator based on the ARM cortex-M4

Abstract

The versatility and closed-loop performance resulting from the use of self-calibrating control systems are two of the most sought features when implementing a digital feedback loop based on embedded systems. However, such methods are typically based on computationally intensive algorithms that, when executed in low-cost embedded systems, severely restrict their usability to application with relatively slow dynamics in order to cope with the control-loop calculations turnaround time. Taking advantage of the new ARM Cortex-M4 microcontroller performance improvements in the digital signal processing field, this paper will present a real-time self-tuning regulator designed for a generic second order dynamic process. To assess the capabilities of this new architecture, a Buck DC-DC converter will be used as test scenario to present comparative measurements of the algorithm's turnaround time and CPU load under different system configurations and results relative to the setpoint tracking capability of the adaptive controller under time-varying dynamics.