Method and controller to control a process

A method for controlling a process wherein a process output signal or a control output signal comprises at least one functional variable and the process output signal is defined for at least one moment;

• the method comprising:
• performing a functional operation in the non-time domain on the signal comprising the functional variable to preserve functional information;
• forming a cost function of at least the signal comprising the functional variable with the preserved functional information;
• performing optimisation of the cost function in which the preserved functional information is included;
• and
• forming based on the optimisation of the cost function at least one process input signal for at least two separate moments for controlling the process.

A controller for controlling a process wherein a process output signal or the control output signal comprises at least one functional variable and the process output signal is defined for at least one moment, wherein the controller is arranged to

• perform a functional operation operation in the non-time domain on the signal comprising the functional variable to preserve functional information;
• form a cost function of at least the signal comprising the functional variable with the preserved functional information;
• perform optimisation of the cost function in which the preserved functional information is included;
• and
• form based on the optimisation of the cost function at least one process input signal for at least two separate moments of time for controlling the process.