A method for controlling the actuation force exerted by a pneumatic actuating device, wherein the actuating device comprises a first working chamber and a second working chamber arranged to be supplied with pressurized air by a source of pressurized air through a first pressure adjuster and a second pressure adjuster, respectively, and wherein each of said first pressure adjuster and second pressure adjuster is arranged to adjust the pressure of the air inside the respective working chambers (14, 16) depending on a control signal, the method being characterised in that it comprises the following iterative steps carried out in real time: a) calculating, by means of an optimization algorithm based on a dynamic model of the actuating device and of said first and second pressure adjusters (20, 22), desired values (u c_d, u o_d) for the control signals for said first and second pressure adjusters (20, 22) in order to generate an actuation force equal to a given desired value (F d) by means of the actuating device, the calculation being carried out by a closed-loop proportional-integral-derivative controller on the basis of the aforementioned desired value (F d) for the actuation force, as well as on an estimated value (F est) for the actuation force and on estimated values (P c_est, P o_est) for the pressures in said first and second working chamber (14, 16) and for the first derivatives (Ṗ c_est, Ṗ o_est) of said pressures, and b) establishing, by means of a state observer, the aforementioned estimated value (F est) for the actuation force, as well as the aforementioned estimated values (P c_est, P o_est) for the pressures in said first and second working chamber (14, 16) and for the first derivatives (Ṗ c_est, Ṗ o_est) of said pressures, on the basis of a measured value (F m) for the actuation force and on measured values (P c, P o) for the pressures in said first and second working chambers (14, 16). wherein the actuating device comprises a first working chamber and a second working chamber arranged to be supplied with pressurized air by a source of pressurized air through a first pressure adjuster and a second pressure adjuster, respectively, and wherein each of said first pressure adjuster and second pressure adjuster is arranged to adjust the pressure of the air inside the respective working chambers (14, 16) depending on a control signal, the method being characterised in that it comprises the following iterative steps carried out in real time: a) calculating, by means of an optimization algorithm based on a dynamic model of the actuating device and of said first and second pressure adjusters (20, 22), desired values (u c_d, u o_d) for the control signals for said first and second pressure adjusters (20, 22) in order to generate an actuation force equal to a given desired value (F d) by means of the actuating device, the calculation being carried out by a closed-loop proportional-integral-derivative controller on the basis of the aforementioned desired value (F d) for the actuation force, as well as on an estimated value (F est) for the actuation force and on estimated values (P c_est, P o_est) for the pressures in said first and second working chamber (14, 16) and for the first derivatives (Ṗ c_est, Ṗ o_est) of said pressures, and b) establishing, by means of a state observer, the aforementioned estimated value (F est) for the actuation force, as well as the aforementioned estimated values (P c_est, P o_est) for the pressures in said first and second working chamber (14, 16) and for the first derivatives (Ṗ c_est, Ṗ o_est) of said pressures, on the basis of a measured value (F m) for the actuation force and on measured values (P c, P o) for the pressures in said first and second working chambers (14, 16). a) calculating, by means of an optimization algorithm based on a dynamic model of the actuating device and of said first and second pressure adjusters (20, 22), desired values (u c_d, u o_d) for the control signals for said first and second pressure adjusters (20, 22) in order to generate an actuation force equal to a given desired value (F d) by means of the actuating device, the calculation being carried out by a closed-loop proportional-integral-derivative controller on the basis of the aforementioned desired value (F d) for the actuation force, as well as on an estimated value (F est) for the actuation force and on estimated values (P c_est, P o_est) for the pressures in said first and second working chamber (14, 16) and for the first derivatives (Ṗ c_est, Ṗ o_est) of said pressures, and b) establishing, by means of a state observer, the aforementioned estimated value (F est) for the actuation force, as well as the aforementioned estimated values (P c_est, P o_est) for the pressures in said first and second working chamber (14, 16) and for the first derivatives (Ṗ c_est, Ṗ o_est) of said pressures, on the basis of a measured value (F m) for the actuation force and on measured values (P c, P o) for the pressures in said first and second working chambers (14, 16).