The Design And Simulation Of Ato Speed Controller Based On Cascade Control Of Gpc And Speed Grading Pid

With the high develop of urban mass transit in our country, in order to ease the urban traffic pressure most cities are in building or planning to build urban mass transit. And with the construction of China’s urbanization process, urban rail transit will get more faster development. Automatic Train Operation System as one of train operation control system, its main task is to replace the driver operation, finish automatically adjust the train speed, train doors PSD control, precise parking train and so on.This paper mainly talk about the design and realize of ATO speed control sub system, let control system can automatically adjust train running speed. Ensure that trains can running punctuality, parking precisely, and running smoothly and comfortably.Paper first analyzes the interference and system key parameters, which may encounter in the process of train running, including the train traction characteristics, control time characteristics, gradient conversion, slip and slide detection and train quality rectification, etc. Then establishes the train dynamic model and analyzes the value changes of model parameters, providing theoretical basis for control algorithm.Based on train dynamics model, using the follow performance of speed and on time running as the direct control objectives, establish the GPC-PID cascade control algorithm, the inner loop control uses target level speed curve as the following input, adopt the PID control algorithm automatically adjusting the train speed so as to follow the target speed. This paper establishes the parameter setting method of PID algorithm from the perspective of attenuation frequency and attenuation angular frequency, and compares the impact of system’s dynamic characteristics and follow performance when using different attenuation frequency and compares the impact when adopting Kp,1/Ti, Kp/Ti, K2p/Ti respectively to take the maximum attenuation angular frequency. Outer loop Control uses on time running as control target, adopting the GPC(Generalized Predictive Control)algorithm to adjust the inner loop input, that is target speed, so as to realize the time adjustment, and analyzes the value changes of the GPC Control parameters with the change of speed. For the accurate train parking and comfort index, this paper respectively through the control strategy of envelope velocity and Jerk rate limit to ensure. Through rational planning of the train operation time and the energy optimization of target level curve, realizing the energy-saving operation of whole urban rail transit system.The setting value of theoretical control algorithm parameters not necessarily be able to achieve optimal quality control. Through experimental identification of the train kinetic parameters, the more accurate control Algorithm’s parameters can be got, so as to better fit the characteristics of the actual control system. Based on optimizing the setting values in the neighborhood of the theoretical control algorithm parameters by the simplex algorithm, to offset the actual environment interference to achieve the optimal quality control(possible local optimum).ATO expects one-breaking rate way to parking the train. The paper using the state space algorithm to calculate the correction value of typical braking rate based on train braking distance and train initial state, and the correction value is the one-breaking rate. Finally, the paper verifies the automatic speed control function of the train through the establishment of simulation system. By analyzing the simulation results show the effectiveness of the control algorithm, and the expected control aim can be reached.