Suspension Based On The Extended State Observer And Nonlinear Pid Digital Control System

Levitation control is one of the kernel technologies of maglev. This paper focuses on the algorithms and developing methods of digital levitation controller of maglev, as shown below:(1) Researching on the Extended State Observer (ESO). The structure and features of ESO which is independent on the model of observed objects are deeply analyzed and the simple Genetic Algorithm (GA) based on the Multi-Objective Optimization methods are introduced to search the optimal parameters of ESO, and get better result.(2) Researching on the hypo-time-optimal current-loop. Based on the analysis of the functions of current-loop in maglev levitation system, a novel current-loop, hypo-time-optimal current-loop, is designed. The results shows that it is as fast as the time-optimal current-loop, and as good as PI current-loop in the performances of steady-state-error and anti-vibration ability.(3) Researching on the non-linear PID controller. Based on the analysis of the characters and the faults of linear PID, the non-linear PID controller is introduced. The non-linear PID, which has overcome the coupling of the parameters, can restrain the overshoot while improve the control speed. Focused on the single electromagnet suspending, the non-linear PID controller has been designed which is based on the hypo-time-optimal current-loop and ESO. The simulator result shows that the ESO can trace after the system out and its differentiator better, while the non-linear PID can accelerate 60% of the adjust speed and decline 40% of the overshoot comparing to the linear PID.(4) Researching on the emulational developing methods for DSP based on PC. The traditional developing methods for the digital levitation controller are exhibited and a novel developing platform based on PC is designed which performed much more prompt. Finally, complete the tests of the units.(5) Researching on the hybrid-magnet levitation experiments using the controller we have designed above. The non-linear PID algorithm is implemented, the quadru-quadrant PWM amplifier and its driving and protection circuits are designed, the analog signals preprocessing circuits are designed. After finishing the debugging of amplifier, hypo-time-optimal current-loop, ESO and soft-levitation, the hybrid-magnet levitation is achieved steadily.