Identification Modelling and Fault-Tolerant Predictive Control for Industrial Input Nonlinear Actuator System

Abstract

Industrial actuator systems play an important role in mechanical manufacture, chemical production and other industrial processes. There is important theoretical research significance and engineering application value in accurately modeling and accurately controlling for an industrial actuator system with dead-zone input nonlinearity. The structure and order of the system are determined by the mechanism relationship of the system. Based on sampled data, an identification algorithm is proposed to describe the main dynamic characteristics of the system output. The convergence property of the proposed identification algorithm is also analyzed. Process faults may reduce the tracking control accuracy of the industrial actuator system. By using an intermediate observer to estimate the faults, a fault-tolerant synchronous control feedback rate is designed to compensate faults. The input dead-zone block may weaken the feedback control performance of the input signal and reduce the control precision. According to the dead-zone input nonlinearity model parameter, a compensator is introduced to transform the dead-zone function into a linear function passing through the origin of coordinates. The transformed and dynamic linear segment of the system constitute the generalized linear system. The model predictive control (MPC) strategy is designed to achieve robust and precise control by eliminating the effects of measurement noise. The results of numerical simulation and experimental test verify the superiority and merit of the modeling and fault-tolerant control strategy. The research results of this paper can provide a good reference and guidance for other complex systems in theoretical research and engineering applications.

Identification Algorithm for Stability Improvement of Welding Robot End-Effector

“…Dong et al proposed an online parametric estimation algorithm under the framework of the least squares algorithm and analyzed the convergence of the algorithm. Numerical simulation and experimental test results verify the superiority and advantages of the algorithm and fault-tolerant control strategy, which can provide good references and guidance for other complex systems in theoretical research and engineering applications [7]. Zhang et al used a hybrid whale optimization algorithm and genetic algorithm (WOA-GA) to identify the dynamic parameters of six robotic joints.…”

“…According to the optimization objective of the actual problem, such genetic algorithms also needed an evaluation function called the fitness function, which determined the choice of the fitness function. The fitness function is generally transformed from the objective function, and Equation (7) shows the fitness function.…”