In asymmetric conditions,the movement and loads of left/right wheels or front/back wheels of the aircraft with multi-wheel or four-wheel bogie landing gears are inconsistent.There are few open literatures related to a...In asymmetric conditions,the movement and loads of left/right wheels or front/back wheels of the aircraft with multi-wheel or four-wheel bogie landing gears are inconsistent.There are few open literatures related to anti-skid braking system for multi-wheels due to technology blockade.In China,the research on multi-channel control and non-equilibrium regulation has just started,and the design of multi-channel control system for anti-skid braking,the simulation of asymmetry taxiing under braking are not studied.In this paper,a dynamics model of ground movement for aircraft with four-wheel bogie landing gears is established for braking simulation, considering the six-degree-of-freedom aircraft body and the movement of bogies and wheels.A multi-channel anti-skid braking system is designed for the wheels of the main landing gears with four-wheel bogies.The eight wheels on left and right landing gears are divided into four groups,and each group is controlled via one channel.The cross protection and self-locked protection modules are added between different channels.A multi-channel anti-skid braking system with slip-ratio control or with slip-velocity control is established separately.Based on the aircraft dynamics model,aircraft braking to stop with anti-skid control on dry runway and on wet runway are simulated.The simulation results demonstrate that in asymmetric conditions,added with cross protection and self-locked protection modules,the slip-ratio-controlled braking system can automatically regulate brake torque to avoid deep slipping and correct aircraft course.The proposed research has reference value for improving brake control effect on wet runway.展开更多
As all-electric aircraft has many advantages,an aircraft nose wheel steering system would be developed to the all-electric direction.Concerning the control demand of the nose wheel steering system,based on the basic p...As all-electric aircraft has many advantages,an aircraft nose wheel steering system would be developed to the all-electric direction.Concerning the control demand of the nose wheel steering system,based on the basic principles of nose wheel steering system and the design technique of mechanotronics,an all-electric aircraft nose wheel steering system,composed of a nose wheel steering mechanism of two worm gear and a control servo system of fly-by-wire with both steering and anti-shimmy functions is designed to meet the demand for operation control in the nose wheel steering system.Then,based on the LMS-AMESim software,the simulation model of the system is established to simulate the dynamics for the verification of its steering function.The simulation results indicate that the nose wheel steering system is reasonable,and can meet the requirements of the general project.Furthermore,the prototypes of the steering mechanism and control system are studied to validate the design,and the steering test bench is prepared to test the designed system.The test results,such as steer angle,rotate speed of motor are analyzed in details and compared with the theoretical results.The analysis and comparison results show that the design is reasonable and the property of the prototype can achieve the design objectives.展开更多
基金supported by National Natural Science Foundation of China (Grant No.51075203)Nanjing University of Aeronautics and Astronautics Research Funding(Grant No.NS2010033)
文摘In asymmetric conditions,the movement and loads of left/right wheels or front/back wheels of the aircraft with multi-wheel or four-wheel bogie landing gears are inconsistent.There are few open literatures related to anti-skid braking system for multi-wheels due to technology blockade.In China,the research on multi-channel control and non-equilibrium regulation has just started,and the design of multi-channel control system for anti-skid braking,the simulation of asymmetry taxiing under braking are not studied.In this paper,a dynamics model of ground movement for aircraft with four-wheel bogie landing gears is established for braking simulation, considering the six-degree-of-freedom aircraft body and the movement of bogies and wheels.A multi-channel anti-skid braking system is designed for the wheels of the main landing gears with four-wheel bogies.The eight wheels on left and right landing gears are divided into four groups,and each group is controlled via one channel.The cross protection and self-locked protection modules are added between different channels.A multi-channel anti-skid braking system with slip-ratio control or with slip-velocity control is established separately.Based on the aircraft dynamics model,aircraft braking to stop with anti-skid control on dry runway and on wet runway are simulated.The simulation results demonstrate that in asymmetric conditions,added with cross protection and self-locked protection modules,the slip-ratio-controlled braking system can automatically regulate brake torque to avoid deep slipping and correct aircraft course.The proposed research has reference value for improving brake control effect on wet runway.
基金supported partly by the Aeronautical Science Foundation of China(No.20142852025)
文摘As all-electric aircraft has many advantages,an aircraft nose wheel steering system would be developed to the all-electric direction.Concerning the control demand of the nose wheel steering system,based on the basic principles of nose wheel steering system and the design technique of mechanotronics,an all-electric aircraft nose wheel steering system,composed of a nose wheel steering mechanism of two worm gear and a control servo system of fly-by-wire with both steering and anti-shimmy functions is designed to meet the demand for operation control in the nose wheel steering system.Then,based on the LMS-AMESim software,the simulation model of the system is established to simulate the dynamics for the verification of its steering function.The simulation results indicate that the nose wheel steering system is reasonable,and can meet the requirements of the general project.Furthermore,the prototypes of the steering mechanism and control system are studied to validate the design,and the steering test bench is prepared to test the designed system.The test results,such as steer angle,rotate speed of motor are analyzed in details and compared with the theoretical results.The analysis and comparison results show that the design is reasonable and the property of the prototype can achieve the design objectives.
