UAV Control in Close Proximities - Ceiling Effect on Battery Lifetime

With the recent developments in the unmanned aerial vehicles (UAV), it is expected them to interact and collaborate with their surrounding objects, other robots and people in order to wisely plan and execute particular tasks. Although these interaction operations are inherently challenging as compared to free-flight missions, they might bring diverse advantages. One of them is their basic aerodynamic interaction during the flight in close proximities which can result in a reduction of the controller effort. In this study, by collecting real-time data, we have observed that the current drawn by the battery can be decreased while flying very close to the surroundings with the help of the ceiling effect. For the first time, this phenomenon is analyzed in terms of battery lifetime degradation by using a simple full equivalent cycle counting method. Results show that cycling related effect on battery degradation can be reduced by a 15.77% if the UAV can utilize ceiling effect.Comment: ICoIAS 201

Laser Graphics in Augmented Reality Applications for Real- World Robot Deployment

Lasers are powerful light source. With their thin shafts of bright light and colours, laser beams can provide a dazzling display matching that of outdoor fireworks. With computer assistance, animated laser graphics can generate eye-catching images against a dark sky. Due to technology constraints, laser images are outlines without any interior fill or detail. On a more functional note, lasers assist in the alignment of components, during installation

EFFECT OF FATIGUE ON RUNNING KINETIC ASYMMETRY IN NONCONTINUOUS & CONTINUOUS CONSTANT SPEED PROTOCOL

Kinetic asymmetries in running gait are well studied but their interaction with muscular fatigue, perceived exertion and/or metabolic stress, need further attention to understand and report limb laterality with fatigue progression during a non-continuous & a continuous constant speed protocols. For study, 13 young male runner's data for kinetic asymmetry (KA), stride rate (SR), blood lactate (BLa), muscular fatigue (RPEM) and overall body feel (RPEo) were collected. Kendall's tau-b reported a non-significant correlation between KA, SR and RPEM and a significant correlation between BLa, RPEo and RPEM whereas Tuckey post hoc test revealed non-significant effect of RPEM on KA and SR in both tests. Findings suggest that, observed KA with fatigue progression may be subject to inter-individual coordinated motor control based on overall running physiological state of body as there has no direct correlation been found with BLa, RPEM and RPEo in this study

Robust Homography Estimation Based on Nonlinear Least Squares Optimization

The homography between image pairs is normally estimated by minimizing a suitable cost function given 2D keypoint correspondences. The correspondences are typically established using descriptor distance of keypoints. However, the correspondences are often incorrect due to ambiguous descriptors which can introduce errors into following homography computing step. There have been numerous attempts to filter out these erroneous correspondences, but it is unlikely to always achieve perfect matching. To deal with this problem, we propose a nonlinear least squares optimization approach to compute homography such that false matches have no or little effect on computed homography. Unlike normal homography computation algorithms, our method formulates not only the keypoints’ geometric relationship but also their descriptor similarity into cost function. Moreover, the cost function is parametrized in such a way that incorrect correspondences can be simultaneously identified while the homography is computed. Experiments show that the proposed approach can perform well even with the presence of a large number of outliers

Accurate IMU Preintegration Using Switched Linear Systems For Autonomous Systems

Employing an inertial measurement unit (IMU) as an additional sensor can dramatically improve both reliability and accuracy of visual/Lidar odometry (VO/LO). Different IMU integration models are introduced using different assumptions on the linear acceleration from the IMU. In this paper, a novel IMU integration model is proposed by using switched linear systems. The proposed approach assumes that both the linear acceleration and the angular velocity in the body frame are constant between two consecutive IMU measurements. This is more realistic in real world situation compared to existing approaches which assume that linear acceleration is constant in the world frame while angular velocity is constant in the body frame between two successive IMU measurements. Experimental results show that the proposed approach outperforms the state-of-the-art IMU integration model. The proposed model is thus important for localization of high speed autonomous vehicles in GPS denied environments.Comment: 19 pages, 2 Figures, Accepted for publication by the IEEE Intelligent Transportation Systems Conference (ITSC 2019). Additionally, Supplementary Derivations on the Pape

OBJECT PERCEPTION IN UNDERWATER ENVIRONMENTS: A SURVEY ON SENSORS AND SENSING METHODOLOGIES

Underwater robots play a critical role in the marine industry. Object perception is the foundation for the automatic operations of submerged vehicles in dynamic aquatic environments. However, underwater perception encounters multiple environmental challenges, including rapid light attenuation, light refraction, or backscattering effect. These problems reduce the sensing devices’ signal-to-noise ratio (SNR), making underwater perception a complicated research topic. This paper describes the state-of-the-art sensing technologies and object perception techniques for underwater robots in different environmental conditions. Due to the current sensing modalities’ various constraints and characteristics, we divide the perception ranges into close-range, medium-range, and long-range. We survey and describe recent advances for each perception range and suggest some potential future research directions worthy of investigating in this field