With the recent advancements in deep learning and computer vision, the AI-powered construction machine such as autonomous excavator has made significant progress. Safety is the most important section in modern construction, where construction machines are more and more automated. In this paper, we propose a vision-based excavator perception, activity analysis, and safety monitoring system. Our perception system could detect multi-class construction machines and humans in real-time while estimating the poses and actions of the excavator. Then, we present a novel safety monitoring and excavator activity analysis system based on the perception result. To evaluate the performance of our method, we collect a dataset using the Autonomous Excavator System (AES) including multi-class of objects in different lighting conditions with human annotations. We also evaluate our method on a benchmark construction dataset. The results showed our YOLO v5 multi-class objects detection model improved inference speed by 8 times (YOLO v5 x-large) to 34 times (YOLO v5 small) compared with Faster R-CNN/ YOLO v3 model. Furthermore, the accuracy of YOLO v5 models is improved by 2.7% (YOLO v5 x-large) while model size is reduced by 63.9% (YOLO v5 x-large) to 93.9% (YOLO v5 small). The experimental results show that the proposed action recognition approach outperforms the state-of-the-art approaches on top-1 accuracy by about 5.18%. The proposed real-time safety monitoring system is not only designed for our Autonomous Excavator System (AES) in solid waste scenes, it can also be applied to general construction scenarios.

The COVID-19 pandemic has revealed the importance of digital fabrication to enable online learning, which remains a challenge for robotics courses. We introduce a teaching methodology that allows students to participate remotely in a hands-on robotics course involving the design and fabrication of robots. Our methodology employs 3D printing techniques with flexible filaments to create innovative soft robots; robots are made from flexible, as opposed to rigid, materials. Students design flexible robotic components such as actuators, sensors, and controllers using CAD software, upload their designs to a remote 3D printing station, monitor the print with a web camera, and inspect the components with lab staff before being mailed for testing and assembly. At the end of the course, students will have iterated through several designs and created fluidically-driven soft robots. Our remote teaching methodology enables educators to utilize 3D printing resources to teach soft robotics and cultivate creativity among students to design novel and innovative robots. Our methodology seeks to democratize robotics engineering by decoupling hands-on learning experiences from expensive equipment in the learning environment.

Building a robot is hard. Building one that can sense its environment and learn how to get around on its own is even harder. But UCLA engineers took on an even bigger challenge. Not only did they create autonomous robots, they 3-D printed them in a single step. Each robot is about the size of a fingertip.

Additive manufacturing is one of the most important technological advances of the 21st century. It's revolutionized the way we build everything from airplanes and wind turbines to medical implants and nano-machinery -- not to mention the tidal wave of creativity unleashed once the tech made its way into the maker community. In Cosplay: A History, veteran cosplayer and 501st Legion member, Andrew Liptak explores the theatrical origins of the craft and its evolution from costuming enthusiasm to full-fledged fandom. Liptak also looks at how advances in technology have impacted the cosplay community -- whether that's the internet forums and social media platforms they use to connect, the phones and cameras they use to publicize their works, and, in the excerpt below, the 3D printers used to create costume components. Excerpted from Cosplay: A History - The Builders, Fans, and Makers Who Bring Your Favorite Stories to Life by Andrew Liptak, published by Simon & Schuster.

Abstract-- This paper presents the DeltaZ robot, a centimeter-scale, low-cost, delta-style robot that allows for a broad range of capabilities and robust functionalities. Current technologies allow DeltaZ to be 3D-printed from soft and rigid materials so that it is easy to assemble and maintain, and lowers the barriers to utilize. Functionality of the robot stems from its three translational degrees of freedom and a closed form kinematic solution which makes manipulation problems more intuitive compared to other manipulators. Moreover, the low cost of the robot presents an opportunity to democratize manipulators for a research setting. We also describe how the robot can be used as a reinforcement learning benchmark. Open-source 3D-printable designs and code are available to the public.

Several machine learning methods can be used to predict ground conditions ahead of TBMs with high accuracy. Ensemble methods have better ground condition prediction accuracy than other machine learning models evaluated. The classification system used in characterizing the ground condition affects the performance of the machine models. The prediction performance of the machine models is different in soils and rocks of different lithologies. There have been significant advances in the use of both unsupervised and supervised machine learning (ML) methods to predict the ground condition or rock mass class ahead of tunnel boring machines (TBMs).

In an article recently published in the journal Additive Manufacturing, researchers discussed computer vision and deep learning for in-situ optimization of thermoset composite additive manufacturing (AM). A new extrusion AM process called direct ink writing (DIW) offers unequaled design flexibility with a wide range of feedstock materials. Although composite DIW has made great strides, this technology still has a long way to go before it can be considered a cornerstone of contemporary composite manufacturing. To consistently produce high-quality prints, it is essential to comprehend the complex interactions between the DIW process, print quality, and material performance. Machine learning (ML) methods can be used to simulate the impacts of process parameters and autonomously optimize the AM as a solution to this issue.

Flying robots are usually rather delicate and require protective enclosures when facing the risk of collision, while high complexity and reduced payload are recurrent problems with collision-resilient flying robots. Inspired by arthropods' exoskeletons, we design a simple, open source, easily manufactured, semi-rigid structure with soft joints that can withstand high-velocity impacts. With an exoskeleton, the protective shell becomes part of the main robot structure, thereby minimizing its loss in payload capacity. Our design is simple to build and customize using cheap components (e.g. bamboo skewers) and consumer-grade 3D printers. The result is CogniFly, a sub-250g autonomous quadcopter that survives multiple collisions at speeds up to 7m/s. In addition to its collision-resiliency, CogniFly is easy to program using Python or Buzz, carries sensors that allow it to fly for approx. 17min without the need of GPS or an external motion capture system, has enough computing power to run deep neural network models on-board and was designed to facilitate integration with an automated battery swapping system. This structure becomes an ideal platform for high-risk activities (such as flying in a cluttered environment or reinforcement learning training) by dramatically reducing the risks of damaging its own hardware or the environment. Source code, 3D files, instructions and videos are available through the project's website (https://thecognifly.github.io).

The additive manufacturing (AM) industry is now almost 40 years old, yet severe problems still persist in yield, accuracy and efficiency. Hard-won breakthroughs in physics, chemistry and engineering have developed prescriptions for the motion of mechatronics, and the dispensing of the materials, the ideal temperature and humidity of processes and machines should follow these equations exactly. Everything, in theory, should turn out perfect, but this is not always the case in practice. Out of a batch of one dozen parts that are 3D-printed, maybe only seven, eight or nine meet structural and functional standards, based on my experience. Additive manufacturing technology is very, very good, but it has not yet fully matured.

The new technique involves a 3D printing process for engineered active materials with multiple functions, or'metamaterials.' It enables the manufacturing of the entire mechanical and electronic systems required for operating a robot at once. After the'meta-bot' has been 3D printed, it can carry out movement, propulsion, sensing, and decision-making.