Method for controlling a stepping motor

A method for controlling the armature of a stepping motor with field windings in main steps and/or micro steps to a target position defined by the target value of a control signal, comprising:

• a control unit including a memory for an angle table with a multitude of addresses, wherein:
• under each of said addresses are stored one step angle and at least two region parameters defining an incrementation region and a decrementation region;
• values of said step angles stored under succeeding incremented addresses increase by a microstep or multiples of a microstep from an initial address having an initial value of zero to a final address having a final value equating a main step;
• a switching device connected to said field windings which controls magnitude and direction of phase currents in said field windings so that a vector of a resulting magnetic field follows a vector angle of said control signal controlling said switching device;
• the method comprising in each interval of a system clock the steps of:
• reading out said step angle and associated region parameters from said memory under an actual address;
• changing said vector angle of said control signal in accordance with said step angle read out from said memory;
• forming an actual value as a sum of all step angles read out from said memory starting from an initial position;
• forming a target deviation as a difference between said actual value and a target value;
• comparing said target deviation with said region parameters to determine in which of said at least two regions said target deviation is located;
• and
• defining an address for a next interval corresponding to a result of said comparison.