An aircraft (100) includes a body (10) and an outer frame (1) rotatably coupled to the body (10). The body (10) includes a plurality of rotary blades (15a-15d) and a driver (14a-14d) configured to rotate the plurality of rotary blades (15a-15d). The outer frame (1) includes a rotary frame (1a-1c) rotatable about a rotation axis intersecting the direction of gravity, and a center of gravity of the plurality of rotary blades (15a-15d) and the driver (14a-14d) is located lower than the rotation axis in the direction of gravity.

An aircraft (100) includes a body (10) and an outer frame (1) rotatably coupled to the body (10). The body (10) includes a plurality of rotary blades (15a-15d) and a driver (14a-14d) configured to rotate the plurality of rotary blades (15a-15d). The outer frame (1) includes a rotary frame (1a-1c) rotatable about a rotation axis intersecting the direction of gravity, and a center of gravity of the plurality of rotary blades (15a-15d) and the driver (14a-14d) is located lower than the rotation axis in the direction of gravity.

Systems and methods are provided for active vibration damping. One embodiment is a method for damping vibration in a mechanical system. The method includes detecting a vibration at a coupling of the mechanical system, generating a countervibration based on the detected vibration, and operating the mechanical system while generating the countervibration.

Systems and methods are provided for active vibration damping. One embodiment is a method for damping vibration in a mechanical system. The method includes detecting a vibration at a coupling of the mechanical system, generating a countervibration based on the detected vibration, and operating the mechanical system while generating the countervibration.

A movable ballast system for an aircraft includes first and second ballast docks secured to the aircraft. The first ballast dock includes a first housing and a first ballast tray secured within the first housing. The first ballast tray includes a plurality of channels. The second ballast dock is positioned aft of a CG of the aircraft and includes a second housing and a second ballast tray secured within the second housing. The second ballast tray includes a plurality of channels. The movable ballast system includes a plurality of movable ballasts, each movable ballast of the plurality of movable ballasts being configured to fit within at least one channel of each of the plurality of channels of the first and second ballast trays.

A movable ballast system for an aircraft includes first and second ballast docks secured to the aircraft. The first ballast dock includes a first housing and a first ballast tray secured within the first housing. The first ballast tray includes a plurality of channels. The second ballast dock is positioned aft of a CG of the aircraft and includes a second housing and a second ballast tray secured within the second housing. The second ballast tray includes a plurality of channels. The movable ballast system includes a plurality of movable ballasts, each movable ballast of the plurality of movable ballasts being configured to fit within at least one channel of each of the plurality of channels of the first and second ballast trays.

A modular energy storage system within a vehicle, wherein the energy storage system comprises a plurality of discrete energy storage units which are movable within the vehicle and selectively securable in a variety of positions.

Vertical take-off and landing (VTOL) aircraft can provide opportunities to incorporate aerial transportation into transportation networks for cities and metropolitan areas. However, VTOL aircraft can be sensitive to uneven weight distributions, e.g., the payload of an aircraft is primarily loaded in the front, back, left, or right. When the aircraft is loaded unevenly, the center of mass of the aircraft may shift substantially enough to negatively impact performance of the aircraft. Thus, in turn, there is an opportunity that the VTOL may be loaded unevenly if seating, luggage placement, and/or positions of internal components are not coordinated. Among other advantages, dynamically assigning the payloads and adjusting components of the VTOL aircraft can increase VTOL safety by ensuring the VTOL aircraft is loaded evenly and meets all weight requirements; can increase transportation efficiency by increasing rider throughput; and can increase the availability of the VTOL services to all potential riders.

A movable ballast system for an aircraft includes first and second ballast docks secured to the aircraft. The first ballast dock includes a first housing and a first ballast tray secured within the first housing. The first ballast tray includes a plurality of channels. The second ballast dock is positioned aft of a CG of the aircraft and includes a second housing and a second ballast tray secured within the second housing. The second ballast tray includes a plurality of channels. The movable ballast system includes a plurality of movable ballasts, each movable ballast of the plurality of movable ballasts being configured to fit within at least one channel of each of the plurality of channels of the first and second ballast trays.

A movable ballast system for an aircraft includes first and second ballast docks secured to the aircraft. The first ballast dock includes a first housing and a first ballast tray secured within the first housing. The first ballast tray includes a plurality of channels. The second ballast dock is positioned aft of a CG of the aircraft and includes a second housing and a second ballast tray secured within the second housing. The second ballast tray includes a plurality of channels. The movable ballast system includes a plurality of movable ballasts, each movable ballast of the plurality of movable ballasts being configured to fit within at least one channel of each of the plurality of channels of the first and second ballast trays.