Design Of Automatic Composite Tape Laying Robot And Process Control Of Taping

Composites with excellent comprehensive mechanical properties have been widely used in aerospace and other fields.Manual placement of composites is time-consuming and difficult to ensure the quality of placement.Automatic composite placement technology is the key of composite placement,which includes automatic tape placement,automatic fiber placement and automatic cloth placement.It can greatly improve the efficiency and quality of composite placement.In this thesis,an automatic composite tape laying robot is developed by taking small curvature aerospace components as laying objects.The robot consist of a self-developed tape head and a six-axis mechanical arm.In this thesis,the control system of tape head is set up to study and realize the control of internal process parameters of prepreg taping and the automatic composite taping of plane and surface.Based on the investigation of the research status of the automatic composite tape laying robot at home and abroad and the automatic composite tape laying process flow,the functional requirements of the automatic composite tape laying robot are summarized,and the overall design of the automatic composite tape laying robot is proposed.The main works done are as follows:(1)Design of the automatic composite tape head and control system.Firstly,the concept of modular design is used to design the tape head,which is the core component of the automatic composite tape laying robot.The roll-laying rewinding device,the main compaction device,the auxiliary compaction device,the ultrasonic cutting device,the heating device and the limit guide device are designed,and the prototype of the tape head is developed.Secondly,The design of the control system is completed from the following three aspects: the motion control and I/O control of the six-axis manipulator,the controller hardware selection and the communication flow design of the tape head,and the software design of the upper computer.(2)Process parameters control of prepreg taping.The prepreg taping system is the core of the tape head,and the main process parameters are taping speed and taping tension.Firstly,the dynamic model of the prepreg taping system is established,namely,the nonlinear system model of double-input and double-output cross-coupling,in which the winding and unwinding motor torque are input and the taping speed and taping tension are output.In view of the cross-coupling nonlinear characteristics of the system,the control strategy intergrating PI(Principal Investigator)control and decoupling control is adopted to realize the decoupling control of taping speed and taping tension.Finally,experiments are carried out respectively in the Matlab/Simulink simulation environment and the prototype.The results show that the RMSEs(Root Mean Square Error)of the speed and tension of taping under the proposed control strategy are 0.0085m/s and 0.593 N,respectively.Compared with PI control,the RRMSEs(RelativeRMSE)are 47.9% and 36.2%,respectively,which verify the effectiveness of the proposed control strategy.(3)Experiments of the automatic composite tape laying.Firstly,the process and mechanism of defect stroke in the composite molding process are analyzed.Then the experiments of planar multi-Angle prepreg taping and curved multi-Angle prepreg taping are carried out.By analyzing incision state,poriness,splicing gap,Lap defects of the layer,evaluating the quality of laminate,the layer is flat without obvious pores,the maximum splicing gap is less than 0.762 mm,and there is no lap defect.The results show that the automatic composite tape laying robot meets the requirements of use.The research in this thesis is helpful to the development of Chinese automatic composite laying equipment technology.The designed automatic composite laying robot has strong stability and good surface adaptability.