Patent ID: 7482776

Claim:
A method of controlling relative movement between a tool of a machine tool and a work piece, the method comprising: dividing a total desired relative tool to workpiece movement in a direction of an axis into a first movement component and a second movement component; controlling the first movement component with a first closed-loop axis control performed by a first position controller configured to control the first movement component; determining a first resulting movement quantity corresponding to the first movement component; feeding a position error from the first closed-loop axis control to a second closed-loop axis control, the position error comprising a difference between the total desired relative tool to workpiece movement and the first resulting movement quantity, wherein the feeding includes adapting the position error before the second closed-loop axis control, thereby generating an adapted quantity being proportional to the position error; controlling the second movement component with the second closed-loop axis control performed by a second position controller configured to control the second movement component, wherein controlling the second movement component includes adjusting for the position error of the first closed-loop axis control; determining a second resulting movement quantity corresponding to the second movement component; and determining a second input quantity for the second position controller by subtracting the second resulting movement quantity from the adapted quantity.