Operating a vehicle with rotors while avoiding a band of rotor rotational speed

An apparatus for operating a vehicle that includes rotors driven by actuators to cause the vehicle to move, the apparatus comprising:

• a memory configured to store computer-readable program code;
• and
• processing circuitry configured to access the memory, and execute the computer-readable program code to cause the apparatus to at least:
• determine rotational speeds at which to drive the rotors to achieve a controlled movement of the vehicle, the rotational speeds including a rotational speed for a rotor of a pair of the rotors driven by a pair of the actuators;
• monitor the rotational speed to detect that the rotational speed has approached or reached a defined avoid band of rotational speeds;
• bias the rotational speed to produce at least one biased rotational speed for respective rotors of the pair that is outside the defined avoid band;
• generate commands for the actuators based on the rotational speeds;
• modify the commands including those of the commands for the pair of the actuators based on the at least one biased rotational speed;
• and
• send the commands to the actuators to cause the actuators to drive the rotors according to the commands, and including those of the commands that are modified so that the pair of the actuators are caused to drive the respective rotors at the at least one biased rotational speed, instead of at the rotational speed.