Design And Commissioning Of Low-gravity Simulation Constant Tension Control System For Mars Rover

Nowadays,with the development of deep space detection technology,China’s space technology needs corresponding space environment simulation equipment urgently.Low-gravity simulation platform is an important part to make spatial simulation come true.And the constant tension system is also an important part of low-gravity simulation platform.It provides a constant tension for the experiment of the space simulation structure through the feedback control technology to offset the gravity of the object itself and realize the simulation movement of this space structure on the ground.This thesis aims at analyzing and designing the constant tension part and its controller in the low-gravity system.First of all,the low-gravity simulation equipment was introduced and their operating characteristics were analyzed in this paper.An auto-disturbance rejection control method is proposed to observe and compensate for the delay problem that existing in the rate-torque dual-loop control mode.Eastablishing mathematical model based on the constant tension system in actual projects and linearizing at the equilibrium position in order to get a linearized model of the constant tension system.Secondly,aiming at the time-delayed disturbance in the constant tension system model,this project adopts the auto-disturbance rejection control technology to establish the system model controller.Observe the uncertain time-delay disturbance and compensate it through the nonlinear extended state observer.Use the nonlinear PD part to realize closed-loop control so that the system has a good anti-disturbance performance.Due to the large number of parameters of the ADRC,the tuning process is so complex that the stability can not be guaranteed.The relationship between the control effect and the parameters is not clear enough.Therefore,this paper first analyzes the components of the ADRC and gi ves the corresponding algorithms including three parts: extended state observer,tracking differentiator and nonlinear state feedback.The system can be simulated based on the designed controller algorithm.Then for the other delay problems in the system,such as the delay between the control signal received from torque motor and its response,and discusses the comprehensive effect of these problems on the constant tension system.Finally,a constant tension simulation system is built based on the actual engineering project background.Design the software structure of the constant tension system,the realization of the lower-computer control algorithm and the communication strategy between the lower-computer and the upper-computer.And gives the constant tension system experiment results.