The Design Of Aerocraft Electric Anti-skid Braking Controller

Aerocraft electric anti-skid braking system is an important part of multi-electric aerocraft, in which braking controller is the most important part. The traditional analog controller is replaced by the digital controller and the hydraulic actuator is replaced by the electromechanical actuator, which improves the aerocraft braking efficiency and performance greatly. According to the aerocraft electric anti-skid braking system's project request, a practical aerocraft electric anti-skid braking controller is designed, the design of the controller hardware and software is introduced in detail and the control stragety is studied in depth.Slip ratio control variable is studied. The paper analyses the relationship between slip ratio and attachment coefficient in detail, aerocraft wheel's force and the anti-skid braking principle. The braking controller is composed of the anti-skid controller and the motor drive controller. The two redundancy actuator is put forward, which is the structure of four brushless DC motors driving four ball screws. The structure of actuator, cross-sectional view and triple geared drive equipment is introduced, and the structure and control principle of permanent-magnet brushless DC motor is analysed. In hardware designing, TMS320F2812 and its peripheral circuit make up the velocity capturing circuit. Anti-skid controller controls slip ratio error and exports braking pressure signal. In the motor drive controller, current sampling circuit, overcurrent protecting circuit, pressure adjusting circuit and signal insulating circuit are made up of TMS320F2812 and its peripheral circuit. CPLD ( EPM7128AE) is employed to deal with the brushless DC motor's rotor postion signal in order to realize commutation. Three-phase full bridge inverting circuit is composed of gate driven IC IR2130 and its peripheral circuit to drive brushless DC motor. In software designing, C language and assembly language together is adopted to control system.The three closed loop strategy with slip ratio loop as the outer one, pressure loop as the middle one and current loop as the inner one is used. Conventional PID is still used to adjust error in control algorithm and is improved.The strategy of the fuzzy control adjusting PID is put forward. The model of the convertional PID control and the fuzzy control are based. According to the simulation curve, system response speed is quicken, over regulation measurement is...