Manipulating multi-core interferences for sensorless electrical drive applications on implementation level

Sensorless control is a preferred solution to meet the increasing demands on quality and functionality in electrical drive applications. For an efficient and future-oriented fulfillment of these performance demanding applications, we propose the use of embedded multi-core systems, for instance to build sensorless multi-axis motor controllers. However, multi-core systems suffer from interferences due to access contentions over shared peripherals. These interferences influence the real-time behavior of the time-critical functions implementing the sensorless operation. Based on the runtime behavior of a two-axis multi-core motor controller operating the sensorless control algorithm Direct Flux Control, we evaluated the relation between the injection interval between consecutive peripheral access requests and the scale of the emerging access delays. This relation can potentially be exploited to decrease the interference rate from 19.2% to 2.9%. Furthermore, with the reorganization of source code, we show two approaches to make use of this relation on implementation level. The results show that for applications exhibiting the runtime behavior of a multi-core motor controller, it is generally possible to manipulate the injection interval on an implementation level in order to reduce multi-core interferences.