Trimming and maneuvering control of a helicopter flight near the ground

Based on a nonlinear flight dynamics model for a single rotor helicopter with ducted tail rotor,a mixed(Newton method/Gradient method) numerical method was proposed to solve helicopter trimming and maneuvering control laws.The effects of ground on trimming and maneuvering control were studied.Taking a typical helicopter as an example,the trims for steady flight with different velocities and altitudes were first solved.Then control laws for lateral jink maneuver were obtained for helicopter NOE(nap of earth) flight.The calculation results conform to the ground effect theory,and load factor and control variation of the maneuver can be used for reference.The theoretical method here can provide the references for the analyses on dynamics and unsteady control in helicopter maneuvering flight near the ground.