scholarly journals A New Shape Adaptive Motion Control System

Author(s):  
Zhiwei Yang

In recent years there is a growing trend on integrating Computer Aid Design (CAD), Computer Aid Manufacturing (CAM) and Computer Aided Inspection (CAI). This thesis presents a new shape adaptive motion control system that integrates part measurement with motion control. The proposed system consists of five blocks: surface measurement; surface reconstruction; tool trajectory planning; axis motion control and part alignment In this thesis, the key technology used in surface measurement and surface reconstruction is spatial spectral analysis. In the surface measurement block, a new special spectrum comparison method is proposed to find out an optimal digitizing frequency. In the surface reconstruction block, different interpolation methods are compared in the spatial spectral domain. A spatial spectral B-Spline method is presented. In the tool trajectory planning block, a method is developed to select the motion profile first and then determine the tool locations according to the reconstructed surface in order to improve the accuracy of the planned path. In the part alignment, a three-point alignment method is presented to align the part coordinates with the machine coordinates. Based on the proposed methods, a software package is developed and implemented on the polishing robot constructed at Ryerson University. The effectiveness of the proposed system has been demonstrated by the experiment on edge polishing. In this experiment, the shape of the part edges is measured first, and then constructed as a wire-frame CAD model, based on which tool trajectory is planned to control the tool to polish the edges.

2021 ◽  
Author(s):  
Zhiwei Yang

In recent years there is a growing trend on integrating Computer Aid Design (CAD), Computer Aid Manufacturing (CAM) and Computer Aided Inspection (CAI). This thesis presents a new shape adaptive motion control system that integrates part measurement with motion control. The proposed system consists of five blocks: surface measurement; surface reconstruction; tool trajectory planning; axis motion control and part alignment In this thesis, the key technology used in surface measurement and surface reconstruction is spatial spectral analysis. In the surface measurement block, a new special spectrum comparison method is proposed to find out an optimal digitizing frequency. In the surface reconstruction block, different interpolation methods are compared in the spatial spectral domain. A spatial spectral B-Spline method is presented. In the tool trajectory planning block, a method is developed to select the motion profile first and then determine the tool locations according to the reconstructed surface in order to improve the accuracy of the planned path. In the part alignment, a three-point alignment method is presented to align the part coordinates with the machine coordinates. Based on the proposed methods, a software package is developed and implemented on the polishing robot constructed at Ryerson University. The effectiveness of the proposed system has been demonstrated by the experiment on edge polishing. In this experiment, the shape of the part edges is measured first, and then constructed as a wire-frame CAD model, based on which tool trajectory is planned to control the tool to polish the edges.


2013 ◽  
Vol 284-287 ◽  
pp. 1909-1913
Author(s):  
Hsin Hung Chou ◽  
Ying Shieh Kung ◽  
Tai Wei Tsui ◽  
Stone Cheng

The novel FPGA (Field Programmable Gate Arrays) can embed a processor to be an SoPC (System-on-a-Programmable-Chip) environment which allows user to design the applications by mixing hardware and software. Therefore, a motion control system of wafer-handling robot based on the SoPC technology is presented in this paper. In FPGA, it is consists of two modules. The first module is Nios II processor which is used to realize the motion trajectory planning and three-axis position/speed controllers by software. The program developed in Nios II processor uses C language. The second module is presented to implement three-axis current vector controllers by hardware, and VHDL (VHSIC Hardware Description Language) is applied to describe the controller behavior. Therefore, a fully digital motion controller for wafer-handling robot, such as three current vector controllers, three position/speed controller and one trajectory planning are all can implemented by a single FPGA chip. Finally, an experimental system constructed by an FPGA experimental board, one three-DOF wafer-handling robot, and three inverters is set up to demonstrate the correctness and effectiveness of the proposed SoPC-based motion control system of wafer-handling robot.


Author(s):  
Nannan Li ◽  
Hongbin Ma ◽  
Qing Fei ◽  
Hao Zhou ◽  
Shaoke Li ◽  
...  

We introduce a real-time motion control system that uses the EtherCAT protocol and apply it to a manipulator with six degrees of freedom. The complexity of a multi-joint manipulator leads to higher requirements for synchronous and real-time performance. EtherCAT technology can greatly improve the performance in terms of accuracy, speed, capability, and band width in industrial control, which is crucial in our robot projects. In this paper, we discuss a servo motion control system based on EtherCAT using IgH as the open-source master station. A Linux operating system is adopted because of the advantages of open-source, high-efficiency, and high-stability operation as well as multi-platform support, which provide more flexibility, freedom, and extendability to developers. Considerable research has been conducted to explore EtherCAT technologies, completely implementing home-made codes with the aid of open-source libraries, debugging the master-slave communication process, and testing the resulting motion controller running on Linux or POSIX-compatible operating systems. To improve the real-time response of servo control, a real-time Xenomai kernel has been compiled, adopted, and tested, and it showed significant enhancement of the real time of a servo motion control system. Furthermore, we explore trajectory planning and inverse kinematic solutions. A trajectory planning method based on B-spline interpolation of three degrees, which makes each part of the trajectory planning curve have relative independence and continuity, is proposed for the kinematic trajectory planning problem in Cartesian space. A coordinate system is established using the modified D-H parameters method to obtain the inverse kinematics of the manipulator. The simulation and experimental results show that the calculation speed of inverse solutions is excellent and the motion of the manipulator is continuous and smooth.


2010 ◽  
Vol 7 ◽  
pp. 109-117
Author(s):  
O.V. Darintsev ◽  
A.B. Migranov ◽  
B.S. Yudintsev

The article deals with the development of a high-speed sensor system for a mobile robot, used in conjunction with an intelligent method of planning trajectories in conditions of high dynamism of the working space.


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