Active Disturbance Rejection Position Synchronous Control of Dual-Hydraulic Actuators with Unknown Dead-Zones

Abstract

In this paper, an integrated control strategy of position synchronization control for dual-electro-hydraulic actuators with unknown dead-zones is proposed. The unified control scheme consists of two parts: One is adaptive dead-zone inverse controllers of each hydraulic actuator to offset the unknown dead-zones. The other is the linear active disturbance rejection controller (LADRC) for position synchronization error. First, the model of the electro-hydraulic proportional position control system (EPPS) was identified by the forgetting factor recursive least square (FFRLS) algorithm. Next, the model reference dead-zone inverse adaptive controller (MRDIAC) was developed to compensate for the delay of actuator response caused by unknown proportional valve dead-zones. Meanwhile, the validity of the adaptive law was proven by the Lyapunov theory. Therefore, the position control accuracy of each hydraulic actuator is guaranteed. Besides, to improve the precision of position synchronization control of dual-hydraulic actuators, a simple and elegant synchronous error-based LADRC was adopted, which applies the total disturbances design concept to eliminate and compensate for motion coupling rather than cross-coupling technology. The performance of the proposed control solution was investigated through extensive comparative experiments based on a hydraulic test platform. The experimental results successfully demonstrate the effectiveness and practicality of the proposed method.

An Improve Nonlinear Robust Control Approach for Robotic Manipulators with PSO-based Global Optimization Strategy

“…Among these algorithms, the PSO is the most popular among many intelligent algorithms due to its simple structure, easy implementation and minor code. This algorithm is proposed by Kennedy and Eberhart in 1995, inspired by bird swarm motion [41], and has been successfully applied to many control fields [42][43][44][45]. For instance, in [42], an ADRC of an induction motor is proposed based on a particle swarm optimization (PSO) algorithm to realize the precise decoupling of the induction motor and the disturbance compensation.…”

“…In [43], the XK-I spherical robot PSO-ADRC motion controller with parameter tuning function is designed by combining the state equation with PSO algorithm. The PSO algorithm is improved by using the genetic algorithm theory to improve the optimization range and convergence rate of the algorithm, and the parameters of the ADRC were adjusted online [45]. However, due to the problems of gradually losing population diversity, falling into local extremum, and low accuracy in the application process of particle swarm optimization, scholars have proposed various improvement measures.…”

Investigation into the Electrohydraulic Synchronous Motion Control of a Thrust System for a Tunnel Boring Machine

“…The results showed that the method can maintain the synchronous accuracy of the double hydraulic cylinders between 0 and 0.66 mm under the condition of satisfying the working requirements of the scissor lift mechanism. Wang et al [24] proposed an integrated control strategy for the position synchronization control of dual electrohydraulic actuators with unknown dead zones. Li et al [25] proposed a design scheme for the mechanical structure of the synchronous precision control of a double-cylinder gantry hydraulic machine.…”

Global identification and compensation of nonlinear variable load for an electrohydraulic system

“…The internal factors are the inherent characteristics of the electrohydraulic system that the regulation of which will not change for a very long time until some parts of the system are failed, including dead zone, hysteresis, friction, and so forth. [11][12][13] Therefore, the models of these internal factors can be obtained by repetitive experiments or some analyzing algorithms. That means a model-based controller can be easily designed to compensate the effect that whatever internal factors bring into the system.…”