Conferences and supporting programme
FOC-SoC - Field-Oriented Control Servo on Chip
Field-Oriented Control (FOC), or Vector Control (VC), is a well-known method for the energy-efficient commutation of electromagnetic motors for almost half a century. So far, FOC was completely implemented in software. There are processors available with integrated hardware supporting base transformations (Clarke, Park, iPark, iClarke) that are required for FOC. In addition to these base transformations, the realization of FOC requires different peripheral function blocks such as pulse width modulation (PWM), analog digital converter (ADC), and interfaces for encoder and for Hall signals (analog or digital), to form a complete FOC servo control system. The initial setup of the FOC is usually very time-consuming and complex, although source code is freely available for various processors. This is because the FOC has many degrees of freedom that all need to fit together in a chain in order to work. Currently available processor architectures used for FOC are limited to PWM bandwidths with a typical range of 20 kHz to 30 kHz for the inner current regulation loop. In contrast to software solutions, a hardware solution allows for PWM frequencies with up to 100 kHz. In addition, a hardware solution allows permanent monitoring of critical limits without eating up performance, unlike software solutions. This article discusses the advantages of a full implementation of the FOC in hardware on a single chip together with ease of use peripheral units for rotor position determination by an encoder and for current measurement with intergraded scaling for signal conditioning as required for FOC. The implementation enfolds the most real-time critical inner FOC current regulation loop, together with the less time critical velocity control loop, and the less time critical position control loop. Altogether, integrated analog and digital building blocks form a Field-Oriented Control Servo on Chip – a FOC-SoC. The integration of the FOC as a SoC (System-on-Chip) drastically reduces the number of required components and reduces the required PCB space. The high integration of FOC, together with velocity controller and position controller as a SoC, enables the FOC as a standard peripheral component that transforms digital information into physical motion. Compact size together with high performance and energy efficiency especially for battery powered mobile systems are enabling factors when embedded goes autonomous.
--- Date: 28.02.2018 Time: 10:30 AM - 11:00 AM Location: Conference Counter NCC Ost