291 research outputs found
TZC: Efficient Inter-Process Communication for Robotics Middleware with Partial Serialization
Inter-process communication (IPC) is one of the core functions of modern
robotics middleware. We propose an efficient IPC technique called TZC (Towards
Zero-Copy). As a core component of TZC, we design a novel algorithm called
partial serialization. Our formulation can generate messages that can be
divided into two parts. During message transmission, one part is transmitted
through a socket and the other part uses shared memory. The part within shared
memory is never copied or serialized during its lifetime. We have integrated
TZC with ROS and ROS2 and find that TZC can be easily combined with current
open-source platforms. By using TZC, the overhead of IPC remains constant when
the message size grows. In particular, when the message size is 4MB (less than
the size of a full HD image), TZC can reduce the overhead of ROS IPC from tens
of milliseconds to hundreds of microseconds and can reduce the overhead of ROS2
IPC from hundreds of milliseconds to less than 1 millisecond. We also
demonstrate the benefits of TZC by integrating with TurtleBot2 that are used in
autonomous driving scenarios. We show that by using TZC, the braking distance
can be shortened by 16% than ROS
A ROS2 based communication architecture for control in collaborative and intelligent automation systems
Collaborative robots are becoming part of intelligent automation systems in
modern industry. Development and control of such systems differs from
traditional automation methods and consequently leads to new challenges.
Thankfully, Robot Operating System (ROS) provides a communication platform and
a vast variety of tools and utilities that can aid that development. However,
it is hard to use ROS in large-scale automation systems due to communication
issues in a distributed setup, hence the development of ROS2. In this paper, a
ROS2 based communication architecture is presented together with an industrial
use-case of a collaborative and intelligent automation system.Comment: 9 pages, 4 figures, 3 tables, to be published in the proceedings of
29th International Conference on Flexible Automation and Intelligent
Manufacturing (FAIM2019), June 201
Comparison of DDS, MQTT, and Zenoh in Edge-to-Edge and Edge-to-Cloud Communication for Distributed ROS 2 Systems
The increased data transmission and number of devices involved in
communications among distributed systems make it challenging yet significantly
necessary to have an efficient and reliable networking middleware. In robotics
and autonomous systems, the wide application of ROS\,2 brings the possibility
of utilizing various networking middlewares together with DDS in ROS\,2 for
better communication among edge devices or between edge devices and the cloud.
However, there is a lack of comprehensive communication performance comparison
of integrating these networking middlewares with ROS\,2. In this study, we
provide a quantitative analysis for the communication performance of utilized
networking middlewares including MQTT and Zenoh alongside DDS in ROS\,2 among a
multiple host system. For a complete and reliable comparison, we calculate the
latency and throughput of these middlewares by sending distinct amounts and
types of data through different network setups including Ethernet, Wi-Fi, and
4G. To further extend the evaluation to real-world application scenarios, we
assess the drift error (the position changes) over time caused by these
networking middlewares with the robot moving in an identical square-shaped
path. Our results show that CycloneDDS performs better under Ethernet while
Zenoh performs better under Wi-Fi and 4G. In the actual robot test, the robot
moving trajectory drift error over time (96\,s) via Zenoh is the smallest. It
is worth noting we have a discussion of the CPU utilization of these networking
middlewares and the performance impact caused by enabling the security feature
in ROS\,2 at the end of the paper.Comment: 19 pages, 8 figures. Submitted to the Journal of Intelligent &
Robotic Systems. Under revie
Study and development of a reliable fiducials-based localization system for multicopter UAVs flying indoor
openThe recent evolution of technology in automation, agriculture, IoT, and aerospace fields
has created a growing demand for mobile robots capable of autonomous operation and
movement to accomplish various tasks. Aerial platforms are expected to play a central
role in the future due to their versatility and swift intervention capabilities. However,
the effective utilization of these platforms faces a significant challenge due to localization,
which is a vital aspect for their interaction with the surrounding environment.
While GNSS localization systems have established themselves as reliable solutions for
open-space scenarios, the same approach is not viable for indoor settings, where localization
remains an open problem as it is witnessed by the lack of extensive literature on
the topic.
In this thesis, we address this challenge by proposing a dependable solution for small
multi-rotor UAVs using a Visual Inertial Odometry localization system. Our KF-based
localization system reconstructs the pose by fusing data from onboard sensors. The primary
source of information stems from the recognition of AprilTags fiducial markers,
strategically placed in known positions to form a “map”.
Building upon prior research and thesis work conducted at our university, we extend
and enhance this system. We begin with a concise introduction, followed by a justification
of our chosen strategies based on the current state of the art. We provide an
overview of the key theoretical, mathematical, and technical aspects that support our
work. These concepts are fundamental to the design of innovative strategies that address
challenges such as data fusion from different AprilTag recognition and the elimination
of misleading measurements. To validate our algorithms and their implementation,
we conduct experimental tests using two distinct platforms by using localization
accuracy and computational complexity as performance indices to demonstrate the
practical viability of our proposed system.
By tackling the critical issue of indoor localization for aerial platforms, this thesis tries
to give some contribution to the advancement of robotics technology, opening avenues
for enhanced autonomy and efficiency across various domains.The recent evolution of technology in automation, agriculture, IoT, and aerospace fields
has created a growing demand for mobile robots capable of autonomous operation and
movement to accomplish various tasks. Aerial platforms are expected to play a central
role in the future due to their versatility and swift intervention capabilities. However,
the effective utilization of these platforms faces a significant challenge due to localization,
which is a vital aspect for their interaction with the surrounding environment.
While GNSS localization systems have established themselves as reliable solutions for
open-space scenarios, the same approach is not viable for indoor settings, where localization
remains an open problem as it is witnessed by the lack of extensive literature on
the topic.
In this thesis, we address this challenge by proposing a dependable solution for small
multi-rotor UAVs using a Visual Inertial Odometry localization system. Our KF-based
localization system reconstructs the pose by fusing data from onboard sensors. The primary
source of information stems from the recognition of AprilTags fiducial markers,
strategically placed in known positions to form a “map”.
Building upon prior research and thesis work conducted at our university, we extend
and enhance this system. We begin with a concise introduction, followed by a justification
of our chosen strategies based on the current state of the art. We provide an
overview of the key theoretical, mathematical, and technical aspects that support our
work. These concepts are fundamental to the design of innovative strategies that address
challenges such as data fusion from different AprilTag recognition and the elimination
of misleading measurements. To validate our algorithms and their implementation,
we conduct experimental tests using two distinct platforms by using localization
accuracy and computational complexity as performance indices to demonstrate the
practical viability of our proposed system.
By tackling the critical issue of indoor localization for aerial platforms, this thesis tries
to give some contribution to the advancement of robotics technology, opening avenues
for enhanced autonomy and efficiency across various domains
Message Flow Analysis with Complex Causal Links for Distributed ROS 2 Systems
Distributed robotic systems rely heavily on the publish-subscribe
communication paradigm and middleware frameworks that support it, such as the
Robot Operating System (ROS), to efficiently implement modular computation
graphs. The ROS 2 executor, a high-level task scheduler which handles ROS 2
messages, is a performance bottleneck. We extend ros2_tracing, a framework with
instrumentation and tools for real-time tracing of ROS 2, with the analysis and
visualization of the flow of messages across distributed ROS 2 systems. Our
method detects one-to-many and many-to-many causal links between input and
output messages, including indirect causal links through simple user-level
annotations. We validate our method on both synthetic and real robotic systems,
and demonstrate its low runtime overhead. Moreover, the underlying intermediate
execution representation database can be further leveraged to extract
additional metrics and high-level results. This can provide valuable timing and
scheduling information to further study and improve the ROS 2 executor as well
as optimize any ROS 2 system. The source code is available at:
https://github.com/christophebedard/ros2-message-flow-analysis.Comment: 14 pages, 12 figure
ACHORD: communication-aware multi-robot coordination with intermittent connectivity
© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksCommunication is an important capability for multi-robot exploration because (1) inter-robot communication (comms) improves coverage efficiency and (2) robot-to-base comms improves situational awareness. Exploring comms-restricted (e.g., subterranean) environments requires a multi-robot system to tolerate and anticipate intermittent connectivity, and to carefully consider comms requirements, otherwise mission-critical data may be lost. In this paper, we describe and analyze ACHORD (Autonomous & Collaborative High-Bandwidth Operations with Radio Droppables), a multi-layer networking solution which tightly co-designs the network architecture and high-level decision-making for improved comms. ACHORD provides bandwidth prioritization and timely and reliable data transfer despite intermittent connectivity. Furthermore, it exposes low-layer networking metrics to the application layer to enable robots to autonomously monitor, map, and extend the network via droppable radios, as well as restore connectivity to improve collaborative exploration. We evaluate our solution with respect to the comms performance in several challenging underground environments including the DARPA SubT Finals competition environment. Our findings support the use of data stratification and flow control to improve bandwidth-usage.Peer ReviewedPostprint (author's final draft
ROS2 versus AUTOSAR: automated PARKING system case-study
Vehicles are complex systems as they combine several engineering disciplines, such as mechanical, electric, electronic, software and telecommunication. In the last decades, most innovations in the automotive domain have been achieved as a combination of electronics and software. Consequently, the software development and deployment has resulted a highly sophisticated engineering process to manage and to integrate. With the introduction of artificial intelligence, automated driving has become a reality. However it has additionally increased the requirements on the system design. One widely accepted approach to manage complexity is to divide the system into subsystems through a well-defined architecture. The architecture of an autonomous system must be suitable to guarantee that the self-driving functionality remains safe in a broad range of operational domains. The challenge is how to design the architecture of the system to be reliable and resilient to changing context. The automotive industry has well established standards and development practices, but it is open to explore and integrate solutions from other domains like Internet of Things and Robotics. In the area of autonomous systems, the capabilities of the robotics middleware ROS2 have been used for prototyping purposes. It is an open question whether ROS2 is suitable for automotive safety relevant applications. This master thesis addresses this challenge through evaluating the possible application of ROS2 in the automotive domain. The development consists of implementing an architecture for an autonomous driving function case-study, an Automated Parking System, which adapts to its context by switching between different operational modes. The Automated Parking System has been implemented and validated in a simulation environment. The experiment results show which benefits bring ROS2 compared with the automotive standardised architecture AUTOSAR
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