Helicopter rotor load reduction and tip clearance control

An apparatus for use in an aircraft having an upper rotor including blades and a coaxial lower rotor including blades, the upper rotor and lower rotor being hingeless, rigid rotors, the apparatus comprising:

• at least one processor;
• and
• memory having instructions stored thereon that, when executed by the at least one processor, cause the apparatus to:
• receive, with the at least one processor, at least one input associated with the aircraft;
• generate, with the at least one processor, flight control signals based on the received at least one input;
• detect, by sensors incorporated into the blades of at least one of the upper or lower rotor, bending moments;
• convert said bending moments into raw bending signals;
• extract, with the at least one processor, harmonic loads from the raw bending signals;
• generate, by the computing device, servo control signals based on the harmonic loads and flight control signals;
• and
• control, with the at least one processor, servos connected to the blades to adjust the blades according to the servo control signals to reduce bending of the blades to improve blade tip clearance between blades on the upper rotor and blades on the lower rotor.

An aircraft comprising:

• an upper and a coaxial lower rotor, each rotor comprising a plurality of blades, wherein each of the plurality of blades is associated with a sensor included in a plurality of sensors, the upper rotor and lower rotor being hingeless, rigid rotors;
• a servo connected to at least one of the blades;
• and
• a control computer configured to:
• receive at least one input associated with the aircraft;
• generate flight control signals based on the received at least one input;
• detect, by sensors incorporated into the blades of at least one of the upper or lower rotor, bending moments;
• convert said bending moments into raw bending signals;
• extract harmonic loads from the raw bending signals;
• generate servo control signals based on the harmonic loads and flight control signals;
• and
• control servos connected to the blades to adjust the blades according to the servo control signals to reduce bending of the blades to improve blade tip clearance between blades on the upper rotor and blades on the lower rotor.