Page 57 - ASME DSCC 2015 Program

Technical Program

clusters that the probe has to travel. Since the CMM travels at a constant A nonlinear Tension Control Scheme for Web Transport Through
low speed and the different probes are of similar shape, size and Heating Processes
comparatively very small weight, the motion dynamics of the CMM does not Contributed regular paper. DSCC2015-9983
influence the total distance travelled for the inspection process. Youwei lu, Prabhakar Pagilla, Oklahoma State University, Stillwater, OK,
Our main contribution is in the development of a spatial algorithm which not United States
only reduces the inter-feature distance but also does that by avoiding the
In this paper we develop a model-based nonlinear tension control scheme
potential for any collision with the feature or the artifact without the use of
for transport of flexible materials (webs) through heating processes. Heat
any computer vision or collision avoidance sensor information. The resulting
transfer processes are widely employed in Roll-to-Roll (R2R) process ma-
spatial algorithm has implicit embedded information of feature clustering,
chines that are used to perform processing operations on a moving web on
which when fed into an optimization algorithm generates a path planning
rollers. Heat transfer processes induce thermal expansion/contraction of the
which would eventually shorten the cycle time. The illustration is done with
flexible material during transport. Because web strain and elastic modulus
two separate simulations.
are functions of temperature distribution in the web, web tension resulting
Trust-Based optimal Subtask Allocation and Model Predictive Control from elastic strain is affected by heating/cooling of the web. Based on a web
for Human-Robot Collaborative Assembly in Manufacturing tension governing equation that includes both elastic and thermal effects,
Contributed regular paper. DSCC2015-9850 a nonlinear tension control scheme is developed for control of tension in
S.M. Mizanoor Rahman, Behzad Sadrfaridpour, Yue Wang, Clemson each tension zone of an R2R system. The control scheme is implemented
University, Clemson, SC, United States on an R2R experimental platform containing two heat transfer rollers, one for
heating the web and one for subsequently cooling the web prior to winding
We develop a one human-one robot hybrid cell for collaborative assembly
of the web. Experimental results are presented and discussed.
in manufacturing. The selected task is to assemble a few LEGO parts into
a final assembled product following specified instructions and sequence
1-22 VIBraTIoN ISSueS IN MechaNIcaL SySTeMS
in collaboration between the human and the robot. We develop a two-lev- 1-22-1 TP1 Vibration Issues in Mechanical Systems
el feedforward optimization strategy that determines the optimal subtask George Bellows A 4:00pm–6:00pm
allocation between the human and the robot for the selected assembly
before the assembly starts. We derive dynamics models for human’s trust in Session Chair: Krishnaswamy Srinivasan, Ohio State University,
the robot and the robot’s trust in the human for the assembly and estimate Columbus, OH, United States
the trusts. The aim is to maintain satisfactory trust levels between the human Session Co-Chair: Isuru Godage, Vanderbilt University, Nashville, TN,
and the robot through the application of the optimal subtask allocation. United States
Again, subtask re-allocation is proposed to regain trusts if the trusts reduce
to below the specified levels. Furthermore, it is hypothesized that fluctua- Dynamic Modeling and Analysis of Thin-wall Plate Machining
tions in human’s trust in the robot may cause fluctuations in human’s speeds Contributed regular paper. DSCC2015-9952
and the human may appreciate if the robot adjusts its speeds with changes
Jiajie Guo, Ruochu liu, Huazhong University of Science and Technology,
in human speeds. Hence, trust-based Model Predictive Control (MPC) is Wuhan, Hubei, China, Kok Meng lee, Georgia Institute of Technology,
proposed to minimize the variations between human and robot speeds and Norcross, GA, United States
to maximize the trusts. Experiment results prove the effectiveness of the hy-
Complex thin-wall component machining has been a challenging task in
brid cell, the feedforward optimal subtask allocation and of the trust-based
advanced manufacturing because distributed deformation and vibration of
MPC. The results also show that the overall assembly performance can be
workpiece render poor precision in final products, which requires displace-
enhanced and the performance status can be monitored through a single
ment field measurements for vibration compensation techniques to enhance
dynamic parameter, i.e. the trust.
product quality. It is desired to capture the distributed and dynamic charac-
Prototype Angle Domain Repetitive Control: Design and Robustness teristics of workpiece during the machining of thin-wall plates. In the context
Contributed regular paper. DSCC2015-9739 of an engineering application where an annular compressor disk is lathe-
Perry Y. li, University of Minnesota, Minneapolis, MN, United States turned on a duplex machine, this paper has developed an analytical method
to capture the effects of stepped thickness on the thin-wall plate dynamics,
Angle-domain repetitive disturbances refer to disturbances that are periodic
where the stepped shape emulates the geometry of a workpiece under
in a generic angle variable which is monotonically increasing with time but
machining. Modal natural frequencies characterizing varying inertia and
not uniformly. This paper extends the classical prototype repetitive control
stiffness are obtained via a formulated boundary value problem, upon which
methodology for time periodic disturbances to this situation. Instead of using
the effects of cutting tool positions on the frequencies and mode shapes are
an internal model approach to derive the control, an affine parameteriza-
analyzed. It also provides numerical verification with finite element analysis
tion approach is adopted which reduces the control design methodology
and validation with experiment.
to one of estimating and canceling the disturbance. While the resulting
control architectures are similar to the classical time-domain periodic case,
the stability conditions are different and depend on the choice of signal
norms. Compensator design for non-minimum phase plants also need to be
modified. Robustness is also considered in the $L_2$ setting and an affine
Q-filter concept is introduced to achieve robust stability.
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