Method for electrical discharge machining

A method for the electrical discharge machining of a workpiece, comprising:

• wherein a plurality of discrete electrical discharge machining pulses are applied to a gap between work piece and electrode, and wherein an open voltage is applied between the electrode and the work piece to induce a discharge, wherein,
• the open voltage of a present pulse is initially applied at an initial open voltage level Uo0, and
• said open voltage is increased to a second open voltage level Uo1 if a discharge does not occur within a first waiting time d0, and
• said open voltage is further increased to a third open voltage level Uo2 if a discharge does not occur within a second waiting time d1, and
• an average of the products sum Wstep of the partial open voltages Uo0, Uo1, Uo2 times the partial ignition delays td0, td1, td2 is computed based on a plurality of pulses, and said average products sum Wstep is compared with the average product Wtec being the product of a previously set reference open voltage U0_tec multiplied by the total ignition delay tdT, and
• a servo setpoint value for the gap width control is adjusted such as to reduce the gap width if the average products sum Wstep is larger than the average product Wtec, and the servo setpoint value is adjusted such as to increase the gap width if the average products sum Wstep is smaller than the average product Wtec.