The Fast Model Predictive Control For Structure Vibration With Time Delays

With the continuous development of science and technology,the scale of engineering structures is more and more large,such as high-rise buildings and large span bridges,etc.As infrastructures and public facilities,the safety and reliability of the large-scale structures in the process of operation are directly related to people's life and property safety,which require extra attention.Necessary control should be applied on the large-scale structures to suppress the harmful vibration.In the meanwhile,the time delay phenomenon is widespread in the industry dynamic system,the delay which exist in the system may affect performance of control systems seriously,eventually may lead to instability for the system.However,due to the large-scale composition of the structures,it is difficult to carry out an efficient and accurate numerical simulation by traditional methods.Therefore,the research on fast algorithm for model predictive control in delay system is of great significance.Based on the motion's essence of linear structural system and time integration methods,expresses the dynamic response as a linear function of the initial disturbance and external load,which is of great help to understand and solve the dynamic problem of linear structural system.This dissertation studies a series of fast model predictive control algorithms for multi-input and long state time-delayed structural systems.The main research contents are as follows:Firstly,for structural dynamic system with multi-input delay,a fast model predictive control algorithm is presented.Based on fast algorithm of no-delay system,by introducing an augmented state vector,the input delay differential equation is transformed into the standard form without any explicit time delay,so as to realize the fast model predictive control for linear structural dynamic system with multi-input delay.Because no approximation and assumption are involved in the whole process,the system performance and stability are easily guaranteed.For linear structural dynamic system,the dynamic explicit formulation is introduced into traditional model predictive control algorithm to compute the system state of each prediction point in a prediction period,which can prevent matrix exponential operation,therefore,the computation efficiency is greatly improved.Furthermore,applying the physical meaning of dynamic explicit formulation to compute the optimal control force,a great number of matrix-matrix multiplications are avoided,which greatly reduces the computation memory,improves the off-line computation efficiency and ensures the on-line computation efficiency.Secondly,for structural dynamic system with state delay,a fast model predictive control algorithm is presented.Based on fast algorithm of no-delay system,by introducing an augmented state vector,the state delay differential equation is transformed into the standard form without any explicit time delay,so as to realize the fast model predictive control for linear structural dynamic system with state delay.Furthermore,applying the physical meaning of dynamic explicit formulation to compute the optimal control force,which greatly improves the off-line computation efficiency and ensures the on-line computation efficiency.