Cooperative Relative Positioning of Mobile Users by Fusing IMU Inertial and UWB Ranging Information

Relative positioning between multiple mobile users is essential for many applications, such as search and rescue in disaster areas or human social interaction. Inertial-measurement unit (IMU) is promising to determine the change of position over short periods of time, but it is very sensitive to error accumulation over long term run. By equipping the mobile users with ranging unit, e.g. ultra-wideband (UWB), it is possible to achieve accurate relative positioning by trilateration-based approaches. As compared to vision or laser-based sensors, the UWB does not need to be with in line-of-sight and provides accurate distance estimation. However, UWB does not provide any bearing information and the communication range is limited, thus UWB alone cannot determine the user location without any ambiguity. In this paper, we propose an approach to combine IMU inertial and UWB ranging measurement for relative positioning between multiple mobile users without the knowledge of the infrastructure. We incorporate the UWB and the IMU measurement into a probabilistic-based framework, which allows to cooperatively position a group of mobile users and recover from positioning failures. We have conducted extensive experiments to demonstrate the benefits of incorporating IMU inertial and UWB ranging measurements.Comment: accepted by ICRA 201

Gait Analysis Using Floor Markers and Inertial Sensors

In this paper, a gait analysis system which estimates step length and foot angles is proposed. A measurement unit, which consists of a camera and inertial sensors, is installed on a shoe. When the foot touches the floor, markers are recognized by the camera to obtain the current position and attitude. A simple planar marker with 4,096 different codes is used. These markers printed on paper are placed on the floor. When the foot is moving off the floor, the position and attitude are estimated using an inertial navigation algorithm. For accurate estimation, a smoother is proposed, where vision information and inertial sensor data are combined. Through experiments, it is shown that the proposed system can both track foot motion and estimate step length

REAL-TIME FACE DETECTION AND HUMAN TRACKING SYSTEM ON FPGA CYCLONE-V

Face detection in image sequence (real-time video stream) has been an active research area in the computer vision field in recent years due to its potential applications such as surveillance cameras, human computer interfaces, smart rooms, intelligent robots and biomedical image analysis. Face detection is a process that determines whether an image has a face or not. In this paper, an embedded system for detecting and tracking human faces in real-time video stream implemented on FPGA DE10-NANO is proposed. The system can be divided into two parts: data streaming, data processing. Experimental results show that the system is capable of accurately detecting faces of up to 5 different people at a distance of up to 1.5 meters from the camera, coexisting in the same frame in resolution of 320x240 pixels with a detection speed of only several hundred milliseconds prove the feasibility of the system. A comparison with similar existing projects will be discussed for evaluation and conclusion as well

Cooperative positioning for emergency responders using self IMU and peer-to-peer radios measurements

Positioning between multiple users without any given infrastructure is essential for many applications, such as emergency response in disaster areas. Traditional approaches based on inertial-measurement units (IMU) are able to measure position changes without any reference, but the accuracy deteriorates due to error accumulation for long terms. Particularly, it is challenging to deal with irregular walking patterns of users. This paper proposes to combine IMU and radio measurements (i.e., peer-to-peer Wifi received signal strength and peer-to-peer UWB ranging) for the positioning of a group of mobile users in emergency response, where no fixed anchors and no infrastructure are available. We incorporate the IMU and radio measurements into the particle filtering, which has the capability to cooperatively position a group of mobile users and recover from any potential tracking failures. By fusing the long-range Wifi RSS and short-range UWB ranging measurements, we can take the advantages of both sensors and achieve an accurate and robust positioning system. We have conducted experiments to validate the proposed approach both in a simulation and a real world experiment. Our experimental results show that the combination of Wifi and UWB measurements provides a positioning accuracy of 2.6 m, which is an improvement of 26% and 10% as compared with Wifi (3.5 m) and UWB (2.9 m) alone.This work is funded by the National Natural Science Foundation of China (No. 61601381 and 61750110529) and the Sichuan Science and Technology Program (No. 2019YFH0161 and 2019JDTD0019)

Effects of various solvent concentration, liquid-solid ratio, temperatures and time values on the extraction yield of anthocyanin from Vietnam Hibiscus sabdariffa L. (Roselle)

Nowadays, the trends in human health and fossil fuel dependent markets present opportunities for agricultural crops as renewable sources in several substitutes of synthetic components in clothing, fuels, and food. This research focused on anthocyanins along with protocatechuic acid and quercetin, which have been recognized as bioactive compounds in Hibiscus sabdariffa L. aqueous extracts. Laboratory extraction study was conducted on various solvent concentration, liquid-solid ratio, temperatures and time values on the extraction yield of anthocyanin from Vietnam Hibiscus sabdariffa L. (Roselle). On theother hand, total anthocyanins wereinvestigated in Hibiscus sabdariffa L. extract as μg/mL cyanidin-3-glucoside (cyd-3-glu). Extraction temperature of 60°C using solvent concentration 50%, extraction time of 30 min at liquid-solid ratio of 8:1 showed the highest anthocyanin recovery at 180,821 mg/L. Overall, Vietnam Hibiscus sabdariffa L. (Roselle) are responsive to anthocyanin extraction, making it an appropriate substrate for the development of industrial colorants and dyes

Effects of Dietary Inclusion of Canthaxanthin- and α-Tocopherol-Loaded Liposomes on Growth and Muscle Pigmentation of Rainbow Trout (Oncorhynchus mykiss)

Dietary inclusion of canthaxanthin, a common carotenoid pigment, has been long practiced in aquaculture to give the favorable flesh color in farmed salmonids. However, carotenoids are associated with limited solubility and poor physicochemical stability, and their dose in fish feed is widely regulated. In this study, we included canthaxanthin- and α-tocopherol-loaded liposomes into fish diets and evaluated the effects of supplemented fish feed on fish growth, color, nutrition, and canthaxanthin deposition in fillets of cultured rainbow trout (Oncorhynchus mykiss). The liposomes were fabricated using lecithin as phospholipids with the initial concentrations (IC = mcanthaxanthin/mlipids, % wt/wt) of canthaxanthin at 0.1%, 0.5%, and 1.0%. Particle size characterization showed that liposome mean sizes were 109.70 ± 6.36, 105.10 ± 8.41, and 109.20 ± 5.66 nm (mean ± SD; n = 3), respectively, corresponding with liposomes synthesized at canthaxanthin IC = 0.1%, IC = 0.5%, and IC = 1%. The polydispersity index (PDI) of all samples remained lower than 0.2. There were no significant differences in the mean size and PDI between blank lecithin liposome and canthaxanthin- and α-tocopherol-loaded liposomes. The encapsulation efficiency of canthaxanthin- and α-tocopherol-loaded liposomes decreased when increasing the concentration of canthaxanthin in lecithin liposomes, with EE% values of IC = 0.1%, IC = 0.5%, and IC = 1% being 85.3 ± 2.1, 72.9 ± 1.8, and 55.3 ± 2.6, respectively. For fish growth, at the end of the experiment, final weight was significantly higher in fish fed with diet supplemented with 1 g/kg canthaxanthin- and α-tocopherol-loaded liposomes (IC = 0.5%) in comparison to other experimental control groups. The difference in color of the salmon muscle was most apparent after two months of feeding. However, after three months, there was no noticeable change in the color score of the fish muscle, indicating saturation of color of the fish muscle. The above results suggest the potential of canthaxanthin- and a-tocopherol-loaded liposomes as the red pigment in fish aquaculture