Do auto-flaps exist?
It can be much simpler than that.

The aerobatic glider Mü-28 has a symmetric airfoil with 20% flaps, and those flaps are automatically set as a function of the g-load experienced near the center of gravity and the dynamic pressure. Basically, a spring-suspended lever with a mass at the end creates the necessary control input. In straight flight they are deflected downwards which makes the airfoil more suitable for gliding, in a zero-g parabola or in a knife-edge flight they are moved to 0° deflection, and in inverted flight they show a negative deflection angle. If flight speed increases, the deflections become proportionally smaller, thus preventing overloading the airframe (which is dimensioned for ±10g, so overloading it is hard anyway).



Mü-28 in inverted flight (picture source). Thanks to the low sun the rear part of the fixed wing section is illuminated so the negative flap deflection is easy to discern.

From this page:


  This innovative automatic flap system fitted to the Mü28 was developed
  at the Flugwissenschaftliche Vereinigung Aachen under the project
  designation FVA-21, controlling the position of the flaps, depending
  on the speed and the load factor, so that the aircraft flies with
  optimal angle of attack in all flight conditions.


Scheduling the maximum deflection angle with dynamic pressure as an overload protection can thus be done in two ways:


Fully mechanically by adding a spring element in the flap linkage.
In a fly-by-wire control system by hard-coding it into the control laws. For faster airplanes this is preferred as it does not require a spring in the system - any elasticity will at some point cause flutter, this is only a question of speed.