Herein provided are methods and systems for controlling operation a first propeller of an aircraft, the first propeller associated with a first engine, the aircraft further comprising a second propeller associated with a second engine. A first requested engine power for the first engine is obtained. A second requested engine power for the second engine is obtained. The first propeller is synchronized with the second propeller by setting a first propeller command for the first propeller based on the first and second requested engine power, and the first propeller command is sent for the first propeller.

Herein provided are methods and systems for controlling operation a first propeller of an aircraft, the first propeller associated with a first engine, the aircraft further comprising a second propeller associated with a second engine. A first requested engine power for the first engine is obtained. A second requested engine power for the second engine is obtained. The first propeller is synchronized with the second propeller by setting a first propeller command for the first propeller based on the first and second requested engine power, and the first propeller command is sent for the first propeller.

Techniques for using an unmanned aerial vehicle (UAV) to deliver a payload while generating an expected sound by the UAV during delivery may be provided. For example, during delivery or while in flight, propellers of different sizes that are associated with the UAV may be instructed to modulate at different rotational speeds to thereby generate an expected sound.

A system with a first turbine rotating in a first direction and a second turbine rotating in a second direction, wherein there is negative clearance associated with blades of the first turbine and the blades of the second turbine.

A system with a first turbine rotating in a first direction and a second turbine rotating in a second direction, wherein there is negative clearance associated with blades of the first turbine and the blades of the second turbine.

Vehicle systems and methods are provided for synchronizing control modules over a communications bus for synchrophasing propellers. A vehicle electrical system includes a communications bus, a bus control module to transmit a first message over the communications bus, a vehicle control module coupled to the bus control module to identify a first timestamp associated with the first message being transmitted in a first clock domain associated with the vehicle control module and provide a subsequent message to the bus control module including the first timestamp, and an actuator control module coupled to the communications bus to identify a second timestamp associated with the first message being received over the communications bus and determine an adjustment to synchronize a second clock domain associated with the actuator control module with the first clock domain based at least in part on a relationship between the first timestamp and the second timestamp.

Herein provided are methods and systems for controlling operation a first propeller of an aircraft, the first propeller associated with a first engine, the aircraft further comprising a second propeller associated with a second engine. A first requested engine power for the first engine is obtained. A second requested engine power for the second engine is obtained. The first propeller is synchronized with the second propeller by setting a first propeller command for the first propeller based on the first and second requested engine power, and the first propeller command is sent for the first propeller.

Herein provided are methods and systems for controlling operation a first propeller of an aircraft, the first propeller associated with a first engine, the aircraft further comprising a second propeller associated with a second engine. A first requested engine power for the first engine is obtained. A second requested engine power for the second engine is obtained. The first propeller is synchronized with the second propeller by setting a first propeller command for the first propeller based on the first and second requested engine power, and the first propeller command is sent for the first propeller.

Herein provided are methods and systems for controlling operation a first propeller of an aircraft, the first propeller associated with a first engine, the aircraft further comprising a second propeller associated with a second engine. A first requested engine power for the first engine is obtained. A second requested engine power for the second engine is obtained. The first propeller is synchronized with the second propeller by setting a first propeller command for the first propeller based on the first and second requested engine power, and the first propeller command is sent for the first propeller.

Herein provided are methods and systems for controlling operation a first propeller of an aircraft, the first propeller associated with a first engine, the aircraft further comprising a second propeller associated with a second engine. A first requested engine power for the first engine is obtained. A second requested engine power for the second engine is obtained. The first propeller is synchronized with the second propeller by setting a first propeller command for the first propeller based on the first and second requested engine power, and the first propeller command is sent for the first propeller.