Method for calibrating a controller of an electric machine, having the following steps: specifying a first signal (S_1) for generating a sinusoidal phase current to energize a winding of an electric machine, characterized by the further steps of: "superimposing" step: superimposing the first signal (S_1) with a test signal (S_Test_i) to generate at least one harmonic oscillation, having a predetermined excitation amplitude and/or phase position relative to the phase current, which is superimposed on the phase current, "detecting" step: detecting a response signal (S_Antw_i) resulting from the superimposition of the phase current and the harmonic oscillation by means of a sensor, repeating the two preceding steps "superimposing" and "detecting" at least three times using different specified test signals (S_Test_i) to generate further harmonic oscillations having specifiable excitation amplitudes and/or phase positions relative to the phase current, which are superimposed on the phase current, ascertaining a minimum of a multiply curved response area (A_Antw), which results as a function of the resulting response signals (S_Antw_i) of the harmonic oscillations generated by means of the test signals (S_Test_i), determining a calibrated signal (S_kal) to generate a harmonic oscillation having a predetermined excitation amplitude and a phase position relative to the phase current as a function of the ascertained minimum, operating the controller of the electric machine; wherein the first signal (S_1) for generating a sinusoidal phase current is specified to energize a winding of the electric machine and the determined calibrated signal (S_kal) is superimposed to generate the harmonic oscillation. specifying a first signal (S_1) for generating a sinusoidal phase current to energize a winding of an electric machine, characterized by the further steps of: "superimposing" step: superimposing the first signal (S_1) with a test signal (S_Test_i) to generate at least one harmonic oscillation, having a predetermined excitation amplitude and/or phase position relative to the phase current, which is superimposed on the phase current, "detecting" step: detecting a response signal (S_Antw_i) resulting from the superimposition of the phase current and the harmonic oscillation by means of a sensor, repeating the two preceding steps "superimposing" and "detecting" at least three times using different specified test signals (S_Test_i) to generate further harmonic oscillations having specifiable excitation amplitudes and/or phase positions relative to the phase current, which are superimposed on the phase current, ascertaining a minimum of a multiply curved response area (A_Antw), which results as a function of the resulting response signals (S_Antw_i) of the harmonic oscillations generated by means of the test signals (S_Test_i), determining a calibrated signal (S_kal) to generate a harmonic oscillation having a predetermined excitation amplitude and a phase position relative to the phase current as a function of the ascertained minimum, operating the controller of the electric machine; wherein the first signal (S_1) for generating a sinusoidal phase current is specified to energize a winding of the electric machine and the determined calibrated signal (S_kal) is superimposed to generate the harmonic oscillation. "superimposing" step: superimposing the first signal (S_1) with a test signal (S_Test_i) to generate at least one harmonic oscillation, having a predetermined excitation amplitude and/or phase position relative to the phase current, which is superimposed on the phase current, "detecting" step: detecting a response signal (S_Antw_i) resulting from the superimposition of the phase current and the harmonic oscillation by means of a sensor, repeating the two preceding steps "superimposing" and "detecting" at least three times using different specified test signals (S_Test_i) to generate further harmonic oscillations having specifiable excitation amplitudes and/or phase positions relative to the phase current, which are superimposed on the phase current, ascertaining a minimum of a multiply curved response area (A_Antw), which results as a function of the resulting response signals (S_Antw_i) of the harmonic oscillations generated by means of the test signals (S_Test_i), determining a calibrated signal (S_kal) to generate a harmonic oscillation having a predetermined excitation amplitude and a phase position relative to the phase current as a function of the ascertained minimum, operating the controller of the electric machine; wherein the first signal (S_1) for generating a sinusoidal phase current is specified to energize a winding of the electric machine and the determined calibrated signal (S_kal) is superimposed to generate the harmonic oscillation.