skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Improved design of the omnidirectional robotic platform for enhancement of manufacturability and commercialability

Abstract

The purpose of this Cooperative Research and Development Agreement (CRADA), between Oak Ridge National Laboratory (ORNL) and Nomadic Technologies, Inc., has been to produce an improved design of the Omnidirectional Holonomic Platform (OHP) that is easier to manufacture and more suitable for commercialization. The OHP technology was developed by the ORNL. In 1993, it received an R&D-100 award and in 1994, a patent was accepted by the U.S. Patent Office in final form (No. 5,374,879). The technology involves a novel wheel system assembly which, through its corresponding control system, can provide rolling platforms with a full omnidirectional motion capability, including simultaneous and independently controlled rotational and translational degrees-of-freedom. The objective of this project has been to pair ORNL`s knowledge of the OHP technology and Nomadic Technologies, Inc.`s experience in manufacturing and market-oriented robotic product development to produce and test an improved design of the OHP.

Authors:
Publication Date:
Research Org.:
Oak Ridge National Lab., TN (United States)
Sponsoring Org.:
USDOE Office of Energy Research, Washington, DC (United States)
OSTI Identifier:
539858
Report Number(s):
ORNL/M-6146
ON: DE98000326; CRN: C/ORNL--95-0338; TRN: 97:005571
DOE Contract Number:
AC05-96OR22464
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Sep 1997
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; ROBOTS; COMMERCIALIZATION; MANUFACTURING; MODIFICATIONS

Citation Formats

Pin, F.G.. Improved design of the omnidirectional robotic platform for enhancement of manufacturability and commercialability. United States: N. p., 1997. Web. doi:10.2172/539858.
Pin, F.G.. Improved design of the omnidirectional robotic platform for enhancement of manufacturability and commercialability. United States. doi:10.2172/539858.
Pin, F.G.. Mon . "Improved design of the omnidirectional robotic platform for enhancement of manufacturability and commercialability". United States. doi:10.2172/539858. https://www.osti.gov/servlets/purl/539858.
@article{osti_539858,
title = {Improved design of the omnidirectional robotic platform for enhancement of manufacturability and commercialability},
author = {Pin, F.G.},
abstractNote = {The purpose of this Cooperative Research and Development Agreement (CRADA), between Oak Ridge National Laboratory (ORNL) and Nomadic Technologies, Inc., has been to produce an improved design of the Omnidirectional Holonomic Platform (OHP) that is easier to manufacture and more suitable for commercialization. The OHP technology was developed by the ORNL. In 1993, it received an R&D-100 award and in 1994, a patent was accepted by the U.S. Patent Office in final form (No. 5,374,879). The technology involves a novel wheel system assembly which, through its corresponding control system, can provide rolling platforms with a full omnidirectional motion capability, including simultaneous and independently controlled rotational and translational degrees-of-freedom. The objective of this project has been to pair ORNL`s knowledge of the OHP technology and Nomadic Technologies, Inc.`s experience in manufacturing and market-oriented robotic product development to produce and test an improved design of the OHP.},
doi = {10.2172/539858},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Sep 01 00:00:00 EDT 1997},
month = {Mon Sep 01 00:00:00 EDT 1997}
}

Technical Report:

Save / Share:
  • For practical robotics application in outdoors or complex environments (e.g. firefighting, warehouse management, floor cleaning, plant surveillance, emergency handling, etc.), mobile robotic platforms are needed for the transport of the manipulative or perceptive robots to various work sites and to assist robot movements at the work site. An ideal platform would be one with full 3-degree-of-freedom (DOF) movement (x, y translation and rotation) to enable tighter navigation and docking, obstacle avoidance, and improved manipulator reach. Three DOFs would also simplify control of the platform and make it more general, thus providing more opportunities for autonomous control. Such a 3-DOF platformmore » based on an orthogonal wheel assembly has been developed at the Oak Ridge National Laboratory and is being used for robotics and artificial intelligence research. This paper presents the mathematical details of the design and control of this type of platform and discusses the experiences and lessons learned with the first prototype. Improvements on the basic wheel assembly as well as optimum platform configurations that are considered for various applications are also discussed.« less
  • Manufacturing tasks that are deemed too hazardous for workers require the use of automation, robotics, and/or other remote handling tools. The associated hazards may be radiological or nonradiological, and based on the characteristics of the environment and processing, a design may necessitate robotic labor, human labor, or both. There are also other factors such as cost, ergonomics, maintenance, and efficiency that also effect task allocation and other design choices. Handling the tradeoffs of these factors can be complex, and lack of experience can be an issue when trying to determine if and what feasible automation/robotics options exist. To address thismore » problem, we utilize common engineering design approaches adapted more for manufacturing system design in hazardous environments. We limit our scope to the conceptual and embodiment design stages, specifically a computational algorithm for concept generation and early design evaluation. In regard to concept generation, we first develop the functional model or function structure for the process, using the common 'verb-noun' format for describing function. A common language or functional basis for manufacturing was developed and utilized to formalize function descriptions and guide rules for function decomposition. Potential components for embodiment are also grouped in terms of this functional language and are stored in a database. The properties of each component are given as quantitative and qualitative criteria. Operators are also rated for task-relevant criteria which are used to address task compatibility. Through the gathering of process requirements/constraints, construction of the component database, and development of the manufacturing basis and rule set, design knowledge is stored and available for computer use. Thus, once the higher level process functions are defined, the computer can automate the synthesis of new design concepts through alternating steps of embodiment and function structure updates/decomposition. In the process, criteria guide function allocation of components/operators and help ensure compatibility and feasibility. Through multiple function assignment options and varied function structures, multiple design concepts are created. All of the generated designs are then evaluated based on a number of relevant evaluation criteria: cost, dose, ergonomics, hazards, efficiency, etc. These criteria are computed using physical properties/parameters of each system based on the qualities an engineer would use to make evaluations. Nuclear processes such as oxide conversion and electrorefining are utilized to aid algorithm development and provide test cases for the completed program. Through our approach, we capture design knowledge related to manufacturing and other operations in hazardous environments to enable a computational program to automatically generate and evaluate system design concepts.« less
  • An interdigitated back contact (IBC) Si wafer solar cell with deposited a-Si heterojunction (HJ) emitter and contacts is considered the ultimate single junction Si solar cell design. This was confirmed in 2014 by both Panasonic and Sharp Solar producing IBC-HJ cells breaking the previous record Si solar cell efficiency of 25%. But manufacturability at low cost is a concern for the complex IBC-HJ device structure. In this research program, our goals were to addressed the broad industry need for a high-efficiency c-Si cell that overcomes the dominant module cost barriers by 1) developing thin Si wafers synthesized by innovative, kerflessmore » techniques; 2) integrating laser-based processing into most aspects of solar cell fabrication, ensuring high speed and low thermal budgets ; 3) developing an all back contact cell structure compatible with thin wafers using a simplified, low-temperature fabrication process; and 4) designing the contact patterning to enable simplified module assembly. There were a number of significant achievements from this 3 year program. Regarding the front surface, we developed and applied new method to characterize critical interface recombination parameters including interface defect density Dit and hole and electron capture cross-section for use as input for 2D simulation of the IBC cell to guide design and loss analysis. We optimized the antireflection and passivation properties of the front surface texture and a-Si/a-SiN/a-SiC stack depositions to obtain a very low (< 6 mA/cm2) front surface optical losses (reflection and absorption) while maintaining excellent surface passivation (SRV<5 cm/s). We worked with kerfless wafer manufacturers to apply defect-engineering techniques to improve bulk minority-carrier lifetime of thin kerfless wafers by both reducing initial impurities during growth and developing post-growth gettering techniques. This led insights about the kinetics of nickel, chromium, and dislocations in PV-grade silicon and to achieving millisecond lifetimes in kerfless silicon materials. Laser fired contacts to n-Si were developed for the first time using a Al/Sb/Ti metal stack giving contact resistances < 5 mOhm-cm2 when fired through several different dielectric layers. A new 2 step laser+chemical etch isolation technique was developed using a sacrificial top coating which avoids laser damage to Si passivation. Regarding the heterojunction emitter, analysis of front FHJ (1D) and IBC (2D) cells with range of p-layer conditions found that a 2-stage high/low doped p-layer was optimum: the low doped region has lower defects giving higher Voc and the high doped region gave a better contact to the metal. A significant effort was spent studying the patterning process and its contribution to degradation of passivation and reproducibility. Several promising new cleaning, contact and deposition patterning and processing approaches were implemented leading to fabrication of several runs with cells having 19-20% efficiency which were stable over several months. This program resulted in the training and support of 12 graduate students, publication of 21 journal papers and 14 conference papers.« less
  • An interdigitated back contact (IBC) Si wafer solar cell with deposited a-Si heterojunction (HJ) emitter and contacts is considered the ultimate single junction Si solar cell design. This was confirmed in 2014 by both Panasonic and Sharp Solar producing IBC-HJ cells breaking the previous record Si solar cell efficiency of 25%. But manufacturability at low cost is a concern for the complex IBC-HJ device structure. In this research program, our goals were to addressed the broad industry need for a high-efficiency c-Si cell that overcomes the dominant module cost barriers by 1) developing thin Si wafers synthesized by innovative, kerflessmore » techniques; 2) integrating laser-based processing into most aspects of solar cell fabrication, ensuring high speed and low thermal budgets ; 3) developing an all back contact cell structure compatible with thin wafers using a simplified, low-temperature fabrication process; and 4) designing the contact patterning to enable simplified module assembly. There were a number of significant achievements from this 3 year program. Regarding the front surface, we developed and applied new method to characterize critical interface recombination parameters including interface defect density Dit and hole and electron capture cross-section for use as input for 2D simulation of the IBC cell to guide design and loss analysis. We optimized the antireflection and passivation properties of the front surface texture and a-Si/a-SiN/a-SiC stack depositions to obtain a very low (< 6 mA/cm2) front surface optical losses (reflection and absorption) while maintaining excellent surface passivation (SRV<5 cm/s). We worked with kerfless wafer manufacturers to apply defect-engineering techniques to improve bulk minority-carrier lifetime of thin kerfless wafers by both reducing initial impurities during growth and developing post-growth gettering techniques. This led insights about the kinetics of nickel, chromium, and dislocations in PV-grade silicon and to achieving millisecond lifetimes in kerfless silicon materials. Laser fired contacts to n-Si were developed for the first time using a Al/Sb/Ti metal stack giving contact resistances < 5 mOhm-cm2 when fired through several different dielectric layers. A new 2 step laser+chemical etch isolation technique was developed using a sacrificial top coating which avoids laser damage to Si passivation. Regarding the heterojunction emitter, analysis of front FHJ (1D) and IBC (2D) cells with range of p-layer conditions found that a 2-stage high/low doped p-layer was optimum: the low doped region has lower defects giving higher Voc and the high doped region gave a better contact to the metal. A significant effort was spent studying the patterning process and its contribution to degradation of passivation and reproducibility. Several promising new cleaning, contact and deposition patterning and processing approaches were implemented leading to fabrication of several runs with cells having 19-20% efficiency which were stable over several months. This program resulted in the training and support of 12 graduate students, publication of 21 journal papers and 14 conference papers.« less