355 research outputs found
Using a Machine Learning Approach to Implement and Evaluate Product Line Features
Bike-sharing systems are a means of smart transportation in urban
environments with the benefit of a positive impact on urban mobility. In this
paper we are interested in studying and modeling the behavior of features that
permit the end user to access, with her/his web browser, the status of the
Bike-Sharing system. In particular, we address features able to make a
prediction on the system state. We propose to use a machine learning approach
to analyze usage patterns and learn computational models of such features from
logs of system usage.
On the one hand, machine learning methodologies provide a powerful and
general means to implement a wide choice of predictive features. On the other
hand, trained machine learning models are provided with a measure of predictive
performance that can be used as a metric to assess the cost-performance
trade-off of the feature. This provides a principled way to assess the runtime
behavior of different components before putting them into operation.Comment: In Proceedings WWV 2015, arXiv:1508.0338
A Factor Graph Approach to Multi-Camera Extrinsic Calibration on Legged Robots
Legged robots are becoming popular not only in research, but also in
industry, where they can demonstrate their superiority over wheeled machines in
a variety of applications. Either when acting as mobile manipulators or just as
all-terrain ground vehicles, these machines need to precisely track the desired
base and end-effector trajectories, perform Simultaneous Localization and
Mapping (SLAM), and move in challenging environments, all while keeping
balance. A crucial aspect for these tasks is that all onboard sensors must be
properly calibrated and synchronized to provide consistent signals for all the
software modules they feed. In this paper, we focus on the problem of
calibrating the relative pose between a set of cameras and the base link of a
quadruped robot. This pose is fundamental to successfully perform sensor
fusion, state estimation, mapping, and any other task requiring visual
feedback. To solve this problem, we propose an approach based on factor graphs
that jointly optimizes the mutual position of the cameras and the robot base
using kinematics and fiducial markers. We also quantitatively compare its
performance with other state-of-the-art methods on the hydraulic quadruped
robot HyQ. The proposed approach is simple, modular, and independent from
external devices other than the fiducial marker.Comment: To appear on "The Third IEEE International Conference on Robotic
Computing (IEEE IRC 2019)
PENINGKATAN KRETIVITAS, MOTIVASI, DAN PRESTASI BELAJAR IPS MENGGUNAKAN MODEL PEMBEAJARAN TEAM GAMES TOURNAMENT
The aim of this research is to improve creativity, motivation, and social sciences students achievement in the fourth grade students of SDN Tunggorono in academic year 2015/2016 using model of learning Team Games Tournament.
The research subjects were 22 fourth grade students of SDN Tunggorono. The research prosedur starting from planning, observation, and reflektion. This research consist of two cycles. The data collection technique are using observation, test, interview, and documentation. The data of creativity, motivation assessed from observation sheet and observed during the learning process. Data analysis technique using percentage (quantitative) and qualitative description. The susses indicator if 75% of student have showing their creativity, very good motivation, and interpretation.
The result showed the creativity of pre test cycle to 40% less than I cycle increased to 72,13% and II cycle to 78,43%. The learning motivation has increased from pre cycle the average percentage of 50% in the first cycle increased to 73,38% and in II cycle to 78,88%. Learning achievement of social science also increased, from pre cycle of in students (63,64%) has not completed study, students (36,36) has completed study. KKM to set for social science in I cycle 50% (II student) has completed study and in II cycle 81,82 (18 students) has completed study. The research have success in II cycle
Automatic Differentiation of Rigid Body Dynamics for Optimal Control and Estimation
Many algorithms for control, optimization and estimation in robotics depend
on derivatives of the underlying system dynamics, e.g. to compute
linearizations, sensitivities or gradient directions. However, we show that
when dealing with Rigid Body Dynamics, these derivatives are difficult to
derive analytically and to implement efficiently. To overcome this issue, we
extend the modelling tool `RobCoGen' to be compatible with Automatic
Differentiation. Additionally, we propose how to automatically obtain the
derivatives and generate highly efficient source code. We highlight the
flexibility and performance of the approach in two application examples. First,
we show a Trajectory Optimization example for the quadrupedal robot HyQ, which
employs auto-differentiation on the dynamics including a contact model. Second,
we present a hardware experiment in which a 6 DoF robotic arm avoids a randomly
moving obstacle in a go-to task by fast, dynamic replanning
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