The principle of electric braking system is analyzed and an anti-skid braking system based on the slip rate control is proposed.The fuzzy-PID controller with parameter self-adjustment feature is designed for the anti-...The principle of electric braking system is analyzed and an anti-skid braking system based on the slip rate control is proposed.The fuzzy-PID controller with parameter self-adjustment feature is designed for the anti-skid braking system.The dynamic model of aircraft ground braking is established in the simulation environment of MATLAB/SIMULINK,and simulation results of dry runway and wet runway are presented.The results show that the fuzzy-PID controller with parameter self-adjustment feature for the electric anti-skid braking system keeps working in the state of stability and the brake efficiencies are increased to 93%on dry runway and 82%on wet runway respectively.展开更多
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
Aiming at the problem of skidding in the operation of a self-propelled high-stem crop sprayer due to uneven road surface and uneven distribution of soil cohesive force,This study proposed a four-wheel drive hydraulic ...Aiming at the problem of skidding in the operation of a self-propelled high-stem crop sprayer due to uneven road surface and uneven distribution of soil cohesive force,This study proposed a four-wheel drive hydraulic anti-skid control system based on RTM valve.Through theoretical analysis of control components such as the RTM valve and steering cylinder,the control model of the anti-skid drive system of the spray machine is established,and the simulation test is carried out in Matlab/Simulink.The simulation results show that the slip rate of the anti-skid drive system based on the PID control strategy is controlled below 0.05,and the RTM valve keeps the driving pressure of the system basically stable.In order to verify the reliability of the simulation results,the designed drive anti-skid control system was carried out on a spray machine for the field test.The experimental results show that the slip rate of the drive anti-skid system decreases from 86.7%to 1.25%when the anti-skid function is turned on,indicating that the designed drive anti-skid system has good anti-skid performance.展开更多
基金Supported by the National Natural Science Foundation of China(51105197,51305198,11372129)the Project Funded by the Priority Academic Program Department of Jiangsu Higher Education Instructions
文摘The principle of electric braking system is analyzed and an anti-skid braking system based on the slip rate control is proposed.The fuzzy-PID controller with parameter self-adjustment feature is designed for the anti-skid braking system.The dynamic model of aircraft ground braking is established in the simulation environment of MATLAB/SIMULINK,and simulation results of dry runway and wet runway are presented.The results show that the fuzzy-PID controller with parameter self-adjustment feature for the electric anti-skid braking system keeps working in the state of stability and the brake efficiencies are increased to 93%on dry runway and 82%on wet runway respectively.
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 by the National Key Research and Development Program of China (Grant No.2016YFD0200705)the Key Laboratory of Northwest Agricultural Equipment of the Ministry of Agriculture and Zhongnong Fengmao Plant Protection Machinery Co.,Ltd.
文摘Aiming at the problem of skidding in the operation of a self-propelled high-stem crop sprayer due to uneven road surface and uneven distribution of soil cohesive force,This study proposed a four-wheel drive hydraulic anti-skid control system based on RTM valve.Through theoretical analysis of control components such as the RTM valve and steering cylinder,the control model of the anti-skid drive system of the spray machine is established,and the simulation test is carried out in Matlab/Simulink.The simulation results show that the slip rate of the anti-skid drive system based on the PID control strategy is controlled below 0.05,and the RTM valve keeps the driving pressure of the system basically stable.In order to verify the reliability of the simulation results,the designed drive anti-skid control system was carried out on a spray machine for the field test.The experimental results show that the slip rate of the drive anti-skid system decreases from 86.7%to 1.25%when the anti-skid function is turned on,indicating that the designed drive anti-skid system has good anti-skid performance.
