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Cable-Suspended Robot System with Real Time Kinematics GPS Position Correction for Algae Harvesting

Pagan, Jesus Manuel
http://orcid.org/0000-0003-2684-719X
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1539256829665799

Abstract Details

2018, Doctor of Philosophy (PhD), Ohio University, Mechanical and Systems Engineering (Engineering and Technology).
Cable-Suspended Parallel Robots (CSPRs) are a class of devices that use three or more winch-activated cables to manipulate an end-effector within a workspace. A distinct advantage of CSPRs is that large payloads can be manipulated over distances that encompass a very large workspace. The application motivating this research (among other commercial applications) is harvesting algae which is commonly used in bioplastics, nutraceuticals, and biofuels. Harvesting algae from one to four acre circulating pond systems is done at significant cost, because it involves pumping the pond water to a centrifuge/filtration system to collect concentrated algae, before transporting it to a central processing location. Thus, an outcome of this research is to collect data using a prototype CSPR system with and without the assistance of GPS corrections to assess the next steps in developing this technology and support cost reductions in commercial algae harvesting. The research presented herein focuses on the requisite precision and accuracy required by the end-effector for this application. To meet these requirements, a unique control scheme incorporating Real Time Kinematics (RTK) and a Global Positioning System (GPS) was developed to significantly improve CSPR positioning. A 1/500th scale prototype CSPR system using RTK and GPS was developed for this research. The system consists of four towers equipped with a central controller and distributed motors and drivers connected via EtherCAT, a high-speed network. A series of tests were performed to demonstrate feasibility and performance of this unique control concept that uses RTK-GPS positional data to correct and improve end-effector positioning. The performance of the CSPR (without RTK-GPS) was first characterized in a well-controlled, indoor environment using a Coordinate Measuring Machine (CMM) with a single point accuracy of 0.001 inch. Subsequent tests were performed outdoors, with and without RTK-GPS activation. For all outdoor tests, point measuring was performed with the RTK-GPS system, with a ± standard deviation range of 0.197 inch in the X and Y directions to 0.394 inch in the Z-direction. Indoor CMM test results indicated maximum (worst case) positional discrepancy of 2.530 inches with a ± standard deviation of 0.370 inch in the X direction. The corresponding deviation magnitude was calculated at this point to be 2.792 inches. The ± standard deviations for all measurements ranged from as low as 0.102 inch to a high of 0.570 inch. Outdoor experiments indicated the potential for substantial improvement in positional accuracy when using the RTK-GPS system. The maximum deviation magnitude with the GPS disabled was 3.259 inches, whereas the maximum positional deviation magnitude ranged from 0.396 inch to 1.789 inch with the GPS enabled. A limitation of the systems precision would depend on the GPS system ability to report a narrow ± standard deviation range below 0.197 inch in longitude and latitude, and 0.394 inch in elevation.
Robert Williams (Advisor)
David Bayless (Committee Member)
Frank Kraft (Committee Member)
Natalie Kruse Daniels (Committee Member)
Morgan Vis-Chiasson (Committee Member)
242 p.
Alternative Energy; Engineering; Mechanical Engineering; Robotics; Robots
Cable-Suspended Robot System; Cable-Suspended Parallel Robot; Cable Robot; Algae Harvesting; Global Positioning System; GPS; Real Time Kinematics; RTK

Recommended Citations

Citations

  • Pagan, J. M. (2018). Cable-Suspended Robot System with Real Time Kinematics GPS Position Correction for Algae Harvesting [Doctoral dissertation, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1539256829665799

    APA Style (7th edition)

  • Pagan, Jesus. Cable-Suspended Robot System with Real Time Kinematics GPS Position Correction for Algae Harvesting. 2018. Ohio University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1539256829665799.

    MLA Style (8th edition)

  • Pagan, Jesus. "Cable-Suspended Robot System with Real Time Kinematics GPS Position Correction for Algae Harvesting." Doctoral dissertation, Ohio University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1539256829665799

    Chicago Manual of Style (17th edition)

ohiou1539256829665799
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© 2018, all rights reserved.
This open access ETD is published by Ohio University and OhioLINK.