3 research outputs found
Unified Modeling of Unconventional Modular and Reconfigurable Manipulation System
Customization of manipulator configurations using modularity and
reconfigurability aspects is receiving much attention. Modules presented so far
in literature deals with the conventional and standard configurations. This
paper presents the 3D printable, light-weight and unconventional modules:
MOIRs' Mark-2, to develop any custom `n'-Degrees-of-Freedom (DoF) serial
manipulator even with the non-parallel and non-perpendicular jointed
configuration. These unconventional designs of modular configurations seek an
easy adaptable solution for both modular assembly and software interfaces for
automatic modeling and control. A strategy of assembling the modules, automatic
and unified modeling of the modular and reconfigurable manipulators with
unconventional parameters is proposed in this paper using the proposed 4
modular units. A reconfigurable software architecture is presented for the
automatic generation of kinematic and dynamic models and configuration files,
through which, a designer can design, validate using visualization, plan and
execute the motion of the developed configuration as required. The framework
developed is based upon an open source platform called as Robot Operating
System (ROS), which acts as a digital twin for the modular configurations. For
the experimental demonstration, a 3D printed modular library is developed and
an unconventional configuration is assembled, using the proposed modules
followed by automatic modeling and control, for a single cell of the vertical
farm setup
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Optimal Compositions using Unconventional Modular Library for Customized Manipulators
This paper presents an optimization approach for generating custom
manipulator configurations using a proposed unconventional modular library. An
end-to-end solution is presented in which the resulting optimal models of the
modular compositions can be integrated directly with the Robot Operating System
platform. The approach utilizes an unconventional modular library, which is
adaptable to a wide range of parameters for customization including
non-parallel and non-perpendicular joint axes, and the unified modeling
technique for getting the custom modular configurations. The single objective
function optimization problem is formulated based upon the discrete parameters
of reconfiguration depending upon the available modular library such as, number
of joint modules, skew-twist angle, intersecting-twist angle, connection ports
of the module, module size, modular sub-assembly unit and curved links. Two
case studies, including an application to the agricultural vertical farms, are
presented to validate the results