We develop custom solutions for multidisciplinary control problems and switched-mode electronics. In most cases the route to a working solution involves dynamic simulation of the system at hand.

Sensorless control of drive systems

We are experts in the field of sensorless control (self-sensing control) of permanent magnet, synchronous reluctance and induction motors. Rotating high speed, low speed and linear motors from watts to megawatts are part of our knowledge base.

We have designed sensorless motor- and generator-controls for helicopter turbines, hybrid buses, range-extenders, e-bikes, bow-thrusters and drones. By understanding stability boundaries and respecting the limitations of the power electronics, mechanical components and CPU, we are able to truly optimize system performance.

Our latest development is MME (micro-motion estimator) that achieves near-perfect servo control on permanent magnet motors (also non-salient types) on all speeds, including standstill, based on just measured voltages and currents.

New developments are ongoing on sensorless control of single-phase linear actuators, three-phase synchronous reluctance machines and magnetic bearing control.

System identification and control

Proper control can only be done with sufficient knowledge of the dynamic behavior and the linearity of the system to be controlled. We develop powerful methods to track changing parameters during normal system operation. Already present frequency components or newly added designed signals that do not disturb the process, are utilized to `excite’ the parameter(s) of interest.

Tracking inductance changes in a linear motor and tracking eigenfrequencies in drill-pipes are a few examples of on-line system identification. Estimating and controlling of ground-force-distortion in seismic shakers was a challenging one.

Electronic circuit design

Electronic Circuit design has many aspects. A given functional description can be obtained by different circuits. However, demands regarding performance, stability, size, weight, acoustic-noise, EMI/EMC, analog/digital(+code), thermal management and cost are often conflicting. We know how to combine analog, digital and code to realize effective solutions.

Data acquisition hardware

Accurate and reliable measurement of physical quantities such as electrical voltages and currents, mechanical position, speed, pressure, temperature or acceleration are less simple than they first appear. We know how to make the effects of aliasing sufficiently small, how to minimize high frequency cross-talk in circuits and how to optimize a shunt-based current measurements with proper Kelvin connections and advanced synchronization between sampler and (PWM) modulator.