Rejection of fixed direction disturbances in multivariable electromechanical motion systems

This work discusses rejection of disturbances with known directions in multivariable motion systems. It is shown how frequency domain tradeoffs in multivariable control motivate a design where the directions of disturbance are considered explicitly. A design method is presented to design multivariable centralized controllers to reject disturbances only in relevant directions. A model of an industrial motion system is used to demonstrate this method. It is shown how the proposed design method resembles the solution of a competing H∞H∞ design and offers the ability to interpret H∞H∞ centralized control solutions understanding the inherent tradeoffs of multivariable feedback control.