Combined actuator with rheological control brake

A combined actuator provided with: a mobile element; a driver for displacing the mobile element; and a rheological control brake, which is mechanically coupled to the mobile element to adjust the displacement of the mobile element; the rheological control brake has: two contiguous adjustment chambers; a rheological fluid contained in the two adjustment chambers; a sliding piston, which tightly separates the two adjustment chambers and is mechanicalli connected to the mobile element; at least one external connection pipe, which reciprocally connects the two adjustment chambers; and a driving device which is coupled to the external connection pipe so as to apply a variable electromagnetic field to the rheological fluid contained in the external connection pipe for varying the viscosity of the rheological fluid between a minimum value and a maximum value.