Research On The Control Of Constant Tension System With Flexibleness

The reaserch of space technology is a complex system engineering.The study of this field which has hign scientific and economic value demonstrates the national comprehensive strength.With the development of space technology in our country,especially in the field of deep space detection and maintainable technology on-orbit,there is a imperious demand on the independent developement of space manipulator.On the other hand,the space environment simulation equipent is very important in testing the performance of the space manipulator.The low-gravity simulation equipment is one kind of space environment simulation equipment of the space manipulator.The constant tension system is the main component of low-gravity simulation equipment,it provides a constant tension which is equal to the gravity of the space manipulator using the feedback control technology which makes the space manipulator able to operate on the ground.This book introduces the low-gravity simulation equipment and analyses the construction of the equipment.Aiming at improving the current mothod of inside loop and outside loop control strategies,a method is proposed using the output moment of motor to achieve the constant tension control.The mathematical model of the constant tension system is then builded,and we get the linearized model of the tension system.After the establishment of the mathematical model,the flexible model of the system was achieved.Instead of using the normally robust control metheds based on multiplicative uncertainties,we choose the loop shaping method based on normalized coprime factorization.After designsing the feedback controller,we analyses the robustness of the controller with perturbations of the flexible vibration frequency.Aiming at studying the transverse vibration and longitudinal vibration of the flexible steel ropes,we finally analyses the influence on the control system.The method proposed in this paper has one problem,that is the friction force have more effects on the control of tension system than the method we used before.We studied some models of the friction phenomenon,and it is finally found that the lugre model is well suited for the control of systems with friction.A feedforward compensation with friction observer is used to solve the problem.The simulation results represents the validity of the method and then we analyse the influence of the sensor noise.Combining with the actual project requirements,this paper introduced the system implementation and the software structure.Some fault treatment methods are introduced.Finally,the results of the experiment are given in this paper.