17 research outputs found
A Manipulator-Assisted Multiple UAV Landing System for USV Subject to Disturbance
Marine waves significantly disturb the unmanned surface vehicle (USV) motion.
An unmanned aerial vehicle (UAV) can hardly land on a USV that undergoes
irregular motion. An oversized landing platform is usually necessary to
guarantee the landing safety, which limits the number of UAVs that can be
carried. We propose a landing system assisted by tether and robot manipulation.
The system can land multiple UAVs without increasing the USV's size. An MPC
controller stabilizes the end-effector and tracks the UAVs, and an adaptive
estimator addresses the disturbance caused by the base motion. The working
strategy of the system is designed to plan the motion of each device. We have
validated the manipulator controller through simulations and well-controlled
indoor experiments. During the field tests, the proposed system caught and
placed the UAVs when the disturbed USV roll range was approximately 12 degrees
A Novel Autonomous Robotics System for Aquaculture Environment Monitoring
Implementing fully automatic unmanned surface vehicles (USVs) monitoring
water quality is challenging since effectively collecting environmental data
while keeping the platform stable and environmental-friendly is hard to
approach. To address this problem, we construct a USV that can automatically
navigate an efficient path to sample water quality parameters in order to
monitor the aquatic environment. The detection device needs to be stable enough
to resist a hostile environment or climates while enormous volumes will disturb
the aquaculture environment. Meanwhile, planning an efficient path for
information collecting needs to deal with the contradiction between the
restriction of energy and the amount of information in the coverage region. To
tackle with mentioned challenges, we provide a USV platform that can perfectly
balance mobility, stability, and portability attributed to its special
round-shape structure and redundancy motion design. For informative planning,
we combined the TSP and CPP algorithms to construct an optimistic plan for
collecting more data within a certain range and limiting energy restrictions.We
designed a fish existence prediction scenario to verify the novel system in
both simulation experiments and field experiments. The novel aquaculture
environment monitoring system significantly reduces the burden of manual
operation in the fishery inspection field. Additionally, the simplicity of the
sensor setup and the minimal cost of the platform enables its other possible
applications in aquatic exploration and commercial utilization
Design and Control of the "TransBoat": A Transformable Unmanned Surface Vehicle for Overwater Construction
This paper presents the TransBoat, a novel omnidirectional unmanned surface
vehicle (USV) with a magnetbased docking system for overwater construction with
wave disturbances. This is the first such USV that can build overwater
structures by transporting modules. The TransBoat incorporates two features
designed to reject wave disturbances. First, the TransBoat's expandable body
structure can actively transform from a mono-hull into a multi-hull for
stabilization in turbulent environments by extending its four outrigger hulls.
Second, a real-time nonlinear model predictive control (NMPC) scheme is
proposed for all shapes of the TransBoat to enhance its maneuverability and
resist disturbance to its movement, based on a nonlinear dynamic model. An
experimental approach is proposed to identify the parameters of the dynamic
model, and a subsequent trajectory tracking test validates the dynamics, NMPC
controller and system mobility. Further, docking experiments identify improved
performance in the expanded form of the TransBoat compared with the contracted
form, including an increased success rate (of ~ 10%) and reduced docking time
(of ~ 40 s on average). Finally, a bridge construction test verifies our system
design and the NMPC control method
Support Vector Machine for Behavior-Based Driver Identification System
We present an intelligent driver
identification system to handle vehicle theft based on modeling
dynamic human behaviors. We propose to recognize illegitimate
drivers through their driving behaviors. Since human driving
behaviors belong to a dynamic biometrical feature which is
complex and difficult to imitate compared with static features
such as passwords and fingerprints, we find that this novel
idea of utilizing human dynamic features for enhanced security
application is more effective. In this paper, we first describe
our experimental platform for collecting and modeling human
driving behaviors. Then we compare fast Fourier transform
(FFT), principal component analysis (PCA), and independent
component analysis (ICA) for data preprocessing. Using machine
learning method of support vector machine (SVM), we derive the individual
driving behavior model and we then demonstrate
the procedure for recognizing different drivers by analyzing
the corresponding models. The experimental results of learning
algorithms and evaluation are described
Design and Verification of a Novel Triphibian Robot
Multi-modal robots expand their operations from one working medium to
another, land to air for example. The majorities of multi-modal robots mainly
refer to platforms that operate in two different media. However, for
all-terrain tasks, there are seldom research to date in the literature.
Generally, locomotions in different working media, i.e. land, water and air,
require different propelling actuators, and thus the triphibian system becomes
bulky. To overcome this challenge, we proposed a triphibian robot and provide
the robot with driving forces to perform all-terrain operations in an efficient
way. A morphable mechanism is designed to enable the transition between
different motion modes, and specifically a cylindrical body is implemented as
the rolling mechanism in land mode. Detailed design principles of different
mechanisms and the transition between various locomotion modes are analyzed.
Finally, a triphibian robot prototype is fabricated and tested in various
working media with both mono-modal and multi-modal functionalities. Experiments
have verified our platform, and the results show promising adaptions in future
exploration tasks in various working scenarios.Comment: IEEE ROBOTICS AND AUTOMATION LETTERS. PREPRINT VERSION,8 page