One of the most important characteristics for many pump applications is being able to accommodate changes in external factors (for example pressure) whilst retaining accurate and consistent performance. In many cases, expensive closed loop systems have been thought to be the only option.
However, in this application, it was absolutely critical that the solution be sensorless. The only option to deliver this exacting requirement was to develop a controller which would read the Back-EMF from the motor and then use this to directly the motor performance against what the user had specified. The controller could then adjust the drive output to correct any changes.