1. A scanning probe microscopy, i.e. SPM, system ( 900 ) comprising, an SPM measurement device ( 903 ); a control device ( 901 , 902 ); wherein the control device is arranged to operate an automatic iterative feedback tuning process comprising steps of: performing a first test with a suitable reference signal as input as set point in a PI regulation algorithm; receiving a result from the first test by receiving at least one sensor signal; using the result from the first test as input to a second test as set point; receiving a result from the second test by receiving at least one sensor signal; determining a positive definitive matrix using results from the first and second test; and calculating new control parameters using the determined matrix.