Modular, flexible, low-cost microstructure measurements: the Epsilometer

2021 ◽  
Author(s):  
Arnaud Le Boyer ◽  
Matthew H. Alford ◽  
Nicole Couto ◽  
Michael Goldin ◽  
Sean Lastuka ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Autonomous Vehicles ◽  
Low Cost ◽  
Temperature Sensors ◽  
Applied Physics ◽  
Noise Floor ◽  
Ship Wake ◽  
Battery Power ◽  
Microstructure Measurements ◽  
Electric Fishing

AbstractThe Epsilometer (“epsi”) is a small (7cm diameter × 30cm long), low-power (0.15 W) and extremely modular microstructure package measuring thermal and kinetic energy dissipation rates, χ and ε. Both the shear probes and FP07 temperature sensors are fabricated in house following techniques developed by Michael Gregg at the Applied Physics Laboratory / University of Washington (APL/UW). Sampling 8 channels (2 shear, 2 temperature, 3-axis accelerometer and a spare for future sensors) at 24 bit precision and 325 Hz, the system can be deployed in standalone mode (battery power and recording to microSD cards) for deployment on autonomous vehicles, wave powered profilers, or it can be used with dropping body termed the “epsi-fish” for profiling from boats, autonomous surface craft or ships with electric fishing reels or other simple winches. The epsi-fish can also be used in real-time mode with the Scripps “fast CTD” winch for fully streaming, altimeter-equipped, line-powered rapid-repeating near-bottom shipboard profiles to 2200 m. Because this winch has a 25ft boom deployable outboard from the ship, contamination by ship wake is reduced 1-2 orders of magnitude in the upper 10-15 m. The noise floor of ε profiles from the epsi-fish is ~ 10−10 W kg−1. This paper describes the fabrication, electronics and characteristics of the system, and documents its performance compared to its predecessor, the APL/UW Modular Microstructure Profiler (MMP).

The Design, Building and Testing of a Trans-Atlantic Autonomous Sailboat

2015 ◽  
Author(s):  
Satchel B. Douglas ◽  
Nolan R. Conway ◽  
Matthew B. Weklar
Keyword(s):  
Open Source ◽  
Autonomous Vehicles ◽  
Low Cost ◽  
Design Decisions ◽  
Hull Form ◽  
Construction Methods ◽  
Autonomous Surface Vehicles ◽  
Marine Industry ◽  
Long Duration ◽  
Rotating Wing

The use of autonomous vehicles is growing in all industries. However, there are no open-source autonomous surface vehicles available in the marine industry. This paper details the design decisions made, construction methods used, and testing performed on a low-cost, open-source vessel. The vessel was designed to cross the Atlantic Ocean as a means of proving its ability to survive the harsh marine environment. A trimaran hull form and free rotating wing sail were used because the combination provided good righting characteristics, durability and low power consumption. The vessel has been shown to navigate autonomously. Total costs were less than $4000 dollars, excluding labor. Vessels of this type could be used for long duration missions recording data in the open ocean at extremely low cost.

scholarly journals Feedforward ins aiding: an investigation of maneuvers for in-flight alignment

2007 ◽  
Vol 18 (4) ◽  
pp. 459-470 ◽  
Author(s):  
Jacques Waldmann
Keyword(s):  
Autonomous Vehicles ◽  
Inertial Sensors ◽  
Low Cost ◽  
Measurement Unit ◽  
Model Mismatch ◽  
External Data ◽  
Rate Gyro ◽  
External Position ◽  
The Impact ◽  
Gyro Drift

Navigation in autonomous vehicles involves integrating measurements from on-board inertial sensors and external data collected by various sensors. In this paper, the computer-frame velocity error model is augmented with a random constant model of accelerometer bias and rate-gyro drift for use in a Kalman filter-based fusion of a low-cost rotating inertial navigation system (INS) with external position and velocity measurements. The impact of model mismatch and maneuvers on the estimation of misalignment and inertial measurement unit (IMU) error is investigated. Previously, the literature focused on analyzing the stripped observability matrix that results from applying piece-wise constant acceleration segments to a stabilized, gimbaled INS to determine the accuracy of misalignment, accelerometer bias, and rate-gyro drift estimation. However, its validation via covariance analysis neglected model mismatch. Here, a vertically undamped, three channel INS with a rotating IMU with respect to the host vehicle is simulated. Such IMU rotation does not require the accurate mechanism of a gimbaled INS (GINS) and obviates the need to maneuver away from the desired trajectory during in-flight alignment (IFA) with a strapdown IMU. In comparison with a stationary GINS at a known location, IMU rotation enhances estimation of accelerometer bias, and partially improves estimation of rate-gyro drift and misalignment. Finally, combining IMU rotation with distinct acceleration segments yields full observability, thus significantly enhancing estimation of rate-gyro drift and misalignment.

scholarly journals Miniaturized Broadband-Multiband Planar Monopole Antenna in Autonomous Vehicles Communication System Device

Electronics ◽  
2021 ◽  
Vol 10 (21) ◽  
pp. 2715
Author(s):  
Ming-An Chung ◽  
Chih-Wei Yang
Keyword(s):  
Communication System ◽  
Autonomous Vehicles ◽  
Low Cost ◽  
Antenna Design ◽  
Dual Band ◽  
Impedance Change ◽  
Antenna Structure ◽  
Low Profile ◽  
Performance Results ◽  
Wireless Standards

The article mainly presents that a simple antenna structure with only two branches can provide the characteristics of dual-band and wide bandwidths. The recommended antenna design is composed of a clockwise spiral shape, and the design has a gradual impedance change. Thus, this antenna is ideal for applications also recommended in these wireless standards, including 5G, B5G, 4G, V2X, ISM band of WLAN, Bluetooth, WiFI 6 band, WiMAX, and Sirius/XM Radio for in-vehicle infotainment systems. The proposed antenna with a dimension of 10 × 5 mm is simple and easy to make and has a lot of copy production. The operating frequency is covered with a dual-band from 2000 to 2742 MHz and from 4062 to beyond 8000 MHz and, it is also demonstrated that the measured performance results of return loss, radiation, and gain are in good agreement with simulations. The radiation efficiency can reach 91% and 93% at the lower and higher bands. Moreover, the antenna gain can achieve 2.7 and 6.75 dBi at the lower and higher bands, respectively. This antenna design has a low profile, low cost, and small size features that may be implemented in autonomous vehicles and mobile IoT communication system devices.

PLA conductive filament for 3D printed smart sensing applications

2018 ◽  
Vol 24 (4) ◽  
pp. 739-743 ◽  
Author(s):  
Simone Luigi Marasso ◽  
Matteo Cocuzza ◽  
Valentina Bertana ◽  
Francesco Perrucci ◽  
Alessio Tommasi ◽  
...  
Keyword(s):  
Temperature Sensor ◽  
Low Cost ◽  
Conductive Polymer ◽  
Temperature Characteristic ◽  
Temperature Sensors ◽  
Electrical Performance ◽  
Content Type ◽  
Sensing Applications ◽  
3D Printed

Purpose This paper aims to present a study on a commercial conductive polylactic acid (PLA) filament and its potential application in a three-dimensional (3D) printed smart cap embedding a resistive temperature sensor made of this material. The final aim of this study is to add a fundamental block to the electrical characterization of printed conductive polymers, which are promising to mimic the electrical performance of metals and semiconductors. The studied PLA filament demonstrates not only to be suitable for a simple 3D printed concept but also to show peculiar characteristics that can be exploited to fabricate freeform low-cost temperature sensors. Design/methodology/approach The first part is focused on the conductive properties of the PLA filament and its temperature dependency. After obtaining a resistance temperature characteristic of this material, the same was used to fabricate a part of a 3D printed smart cap. Findings An approach to the characterization of the 3D printed conductive polymer has been presented. The major results are related to the definition of resistance vs temperature characteristic of the material. This model was then exploited to design a temperature sensor embedded in a 3D printed smart cap. Practical implications This study demonstrates that commercial conductive PLA filaments can be suitable materials for 3D printed low-cost temperature sensors or constitutive parts of a 3D printed smart object. Originality/value The paper clearly demonstrates that a new generation of 3D printed smart objects can already be obtained using low-cost commercial materials.

A network of low-cost temperature sensors for real-time monitoring of combined sewer overflow

2021 ◽  
Author(s):  
Mathias Riechel ◽  
Oriol Gutierrez ◽  
Silvia Busquets ◽  
Neus Amela ◽  
Valentina Dimova ◽  
...  
Keyword(s):  
Real Time ◽  
Low Cost ◽  
Temperature Sensors ◽  
Sensor Technology ◽  
Detection Accuracy ◽  
Combined Sewer Overflow ◽  
Monitoring Equipment ◽  
Flow Monitoring ◽  
Combined Sewer ◽  
Sewer Overflow

<p>The H2020 innovation project digital-water.city (DWC) aims at boosting the integrated management of water systems in five major European cities – Berlin, Copenhagen, Milan, Paris and Sofia – by leveraging the potential of data and digital technologies. The goal is to quantify the benefits of a panel of 15 innovative digital solutions and achieve their long-term uptake and successful integration in the existing digital systems and governance processes. One of these promising technologies is a new generation of sensors for measuring combined sewer overflow occurrence, developed by ICRA and IoTsens.</p><p>Recent EU regulations have correctly identified CSOs as an important source of contamination and promote appropriate monitoring of all CSO structures in order to control and avoid the detrimental effects on receiving waters. Traditionally there has been a lack of reliable data on the occurrence of CSOs, with the main limitations being: i) the high number of CSO structures per municipality or catchment and ii) the high cost of the flow-monitoring equipment available on the market to measure CSO events. These two factors and the technical constraints of accessing and installing monitoring equipment in some CSO structures have delayed the implementation of extensive monitoring of CSOs. As a result, utilities lack information about the behaviour of the network and potential impacts on the local water bodies.</p><p>The new sensor technology developed by ICRA and IoTsens provides a simple yet robust method for CSO detection based on the deployment of a network of innovative low-cost temperature sensors. The technology reduces CAPEX and OPEX for CSO monitoring, compared to classical flow or water level measurements, and allows utilities to monitor their network extensively. The sensors are installed at the overflows crest and measure air temperature during dry-weather conditions and water temperature when the overflow crest is submerged in case of a CSO event. A CSO event and its duration can be detected by a shift in observed temperature, thanks to the temperature difference between the air and the water phase. Artificial intelligence algorithms further help to convert the continuous measurements into binary information on CSO occurrence. The sensors can quantify the CSO occurrence and duration and remotely provide real-time overflow information through LoRaWAN/2G communication protocols.</p><p>The solution is being deployed since October 2020 in the cities of Sofia, Bulgaria, and Berlin, Germany, with 10 offline sensors installed in each city to improve knowledge on CSO emissions. Further 36 (Sofia) and 9 (Berlin) online sensors will follow this winter. Besides its main goal of improving knowledge on CSO emissions, data in Sofia will also be used to identify suspected dry-weather overflows due to blockages. In Berlin, data will be used to improve the accuracy of an existing hydrodynamic sewer model for resilience analysis, flood forecasting and efficient investment in stormwater management measures. First results show a good detection accuracy of CSO events with the offline version of the technology. As measurements are ongoing and further sensors will be added, an enhanced set of results will be presented at the conference.</p><p>Visit us: https://www.digital-water.city/ </p><p>Follow us: Twitter (@digitalwater_eu); LinkedIn (digital-water.city)</p>

scholarly journals Hierarchically patterned self-powered sensors for multifunctional tactile sensing

2020 ◽  
Vol 6 (34) ◽  
pp. eabb9083 ◽  
Author(s):  
Yang Wang ◽  
Heting Wu ◽  
Lin Xu ◽  
Hainan Zhang ◽  
Ya Yang ◽  
...  
Keyword(s):  
Low Cost ◽  
Fast Response ◽  
Temperature Sensors ◽  
Physical Contact ◽  
Tactile Sensing ◽  
Material Identification ◽  
Flexible Sensors ◽  
Temperature Stimulus ◽  
Self Powered ◽  
Multifunctional Sensor

Flexible sensors are highly desirable for tactile sensing and wearable devices. Previous researches of smart elements have focused on flexible pressure or temperature sensors. However, realizing material identification remains a challenge. Here, we report a multifunctional sensor composed of hydrophobic films and graphene/polydimethylsiloxane sponges. By engineering and optimizing sponges, the fabricated sensor exhibits a high-pressure sensitivity of >15.22 per kilopascal, a fast response time of <74 millisecond, and a high stability over >3000 cycles. In the case of temperature stimulus, the sensor exhibits a temperature-sensing resolution of 1 kelvin via the thermoelectric effect. The sensor can generate output voltage signals after physical contact with different flat materials based on contact-induced electrification. The corresponding signals can be, in turn, used to infer material properties. This multifunctional sensor is excellent in its low cost and material identification, which provides a design concept for meeting the challenges in functional electronics.

A Low-Cost MPC-Based Algorithm for Battery Power Limit Estimation

2020 ◽  
Author(s):  
Marcelo A. Xavier ◽  
Aloisio Kawakita de Souza ◽  
Gregory L. Plett ◽  
M. Scott Trimboli
Keyword(s):  
Low Cost ◽  
Battery Power ◽  
Power Limit

Low-Cost Receiver and Network Real-Time Kinematic Positioning for use in Connected and Autonomous Vehicles

2019 ◽  
Vol 72 (04) ◽  
pp. 917-930
Author(s):  
Fang-Shii Ning ◽  
Xiaolin Meng ◽  
Yi-Ting Wang
Keyword(s):  
Real Time ◽  
Autonomous Vehicles ◽  
High Performance ◽  
Low Cost ◽  
Satellite System ◽  
High Accuracy ◽  
Future Trend ◽  
Intelligent Transport System ◽  
Positioning System ◽  
Gnss Receiver

Connected and Autonomous Vehicles (CAVs) have been researched extensively for solving traffic issues and for realising the concept of an intelligent transport system. A well-developed positioning system is critical for CAVs to achieve these aims. The system should provide high accuracy, mobility, continuity, flexibility and scalability. However, high-performance equipment is too expensive for the commercial use of CAVs; therefore, the use of a low-cost Global Navigation Satellite System (GNSS) receiver to achieve real-time, high-accuracy and ubiquitous positioning performance will be a future trend. This research used RTKLIB software to develop a low-cost GNSS receiver positioning system and assessed the developed positioning system according to the requirements of CAV applications. Kinematic tests were conducted to evaluate the positioning performance of the low-cost receiver in a CAV driving environment based on the accuracy requirements of CAVs. The results showed that the low-cost receiver satisfied the “Where in Lane” accuracy level (0·5 m) and achieved a similar positioning performance in rural, interurban, urban and motorway areas.

Characterizing Lane Changes via Digitized Infrastructure and Low-Cost GPS

2019 ◽  
Vol 2673 (8) ◽  
pp. 298-309 ◽  
Author(s):  
Ishtiak Ahmed ◽  
Alan Karr ◽  
Nagui M. Rouphail ◽  
Gyounghoon Chun ◽  
Shams Tanvir
Keyword(s):  
Autonomous Vehicles ◽  
Lateral Displacement ◽  
Low Cost ◽  
Detection Algorithm ◽  
Lane Change ◽  
Trajectory Data ◽  
Lane Changing ◽  
Lane Changes ◽  
Detection Systems ◽  
Level Information

With the expected increase in the availability of trajectory-level information from connected and autonomous vehicles, issues of lane changing behavior that were difficult to assess with traditional freeway detection systems can now begin to be addressed. This study presents the development and application of a lane change detection algorithm that uses trajectory data from a low-cost GPS-equipped fleet, supplemented with digitized lane markings. The proposed algorithm minimizes the effect of GPS errors by constraining the temporal duration and lateral displacement of a lane change detected using preliminary lane positioning. The algorithm was applied to 637 naturalistic trajectories traversing a long weaving segment and validated through a series of controlled lane change experiments. Analysis of naturalistic trajectory data revealed that ramp-to-freeway trips had the highest number of discretionary lane changes in excess of 1 lane change/vehicle. Overall, excessive lane change rates were highest between the two middle freeway lanes at 0.86 lane changes/vehicle. These results indicate that extreme lane changing behavior may significantly contribute to the peak-hour congestion at the site. The average lateral speed during lane change was 2.7 fps, consistent with the literature, with several freeway–freeway and ramp–ramp trajectories showing speeds up to 7.7 fps. All ramp-to-freeway vehicles executed their first mandatory lane change within 62.5% of the total weaving length, although other weaving lane changes were spread over the entire segment. These findings can be useful for implementing strategies to lessen abrupt and excessive lane changes through better lane pre-positioning.

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