Refer to figure.
With a fully powered flying control the pilot is unaware of the aerodynamic force on the controls, so it is necessary to incorporate “artificial feel" to prevent the aircraft from being overstressed.

As shown schematically in the diagram, a device sensitive to dynamic pressure (1⁄2 ρ V²). Pitot pressure is fed to one side of a chamber and static pressure to the other, which moves a diaphragm under the influence of changing dynamic pressure with airspeed. This causes “regulated” hydraulic pressure to provide a resistance or ‘feel’ on the pilot’s input controls proportional to IAS², just as in a manual control. In addition, stick force should increase as stick displacement increases.

An advantage of artificial feel is that it can be configured to provide envelope protection, which prevents the pilot over stressing the aircraft. The Boeing777 fly- by-wire system employs envelope protection. This feature of the artificial-feel system provides increasingly greater force when the aircraft is pushed to its limits.