Study review of the electrical power generation: Wave energy converting device system from the swell

This paper presents the design of an innovative wave energy converter, namely, Electrical Power Generation - WEC Device System from the Swell, abbreviated as WECFS. This WEC device has been registered for a patent in the Spanish Office of the Patents and Brands (OEPM) with the registration number of the innovative utility model-Patent Model: 202131440(5). The study reported in this paper endeavours to demonstrate the technical feasibility, functional mechanical-kinematic behaviour, and the performance of the proof-of-concept WEC device system, in order to determine their energy extraction capacities and functionalities. The overall energy extracted with eight electrical generators A/C is 0.185 MWatts calculated analytically. The levelized cost of energy is a very important metric in determining whether to move forward with the project, where the cost of energy target has been as cheap as $0.07kWh; this value of LCOE could be improved with optimisations on the practical design parameters. This preliminary study investigates the factors influencing standardized and industrialized for the new WEC device system and can be used to guide the optimization of this type of device technology.

A distributed simulation study to investigate pedestrians’ head-turning behaviour when crossing in response to automated and human-driven vehicles displaying different braking patterns

This distributed simulator study investigated pedestrians’ head-turning behaviour during a series of road crossings in a CAVE-based pedestrian simulator. Pedestrians were required to cross the road in front of an approaching vehicle, the kinematic behaviour of which was either programmed by the simulation to depict an automated vehicle (AV) or controlled by a human driver (HD), via a connected (hidden) desktop driving simulator. A within-participant experimental design was used with twenty-five pairs of participants (a pedestrian and a driver). For each trial, pedestrians had to decide whether to cross in front of the HD/AV, which was instructed (or programmed) to yield (or not) to the pedestrian. For the AV trials, two braking patterns were included: a hard-braking AV (AVHB, deceleration rate = 3.2 m/s2, stopping distance = 12 m from pedestrian) and soft-braking (AVSB, deceleration rate = 2.5 m/s2, stopping distance = 4 m from pedestrian). Pedestrians’ head-turning frequency and the change in head-turning angle, were calculated for each condition, both before a crossing was initiated, and during the actual road crossing. Results showed a significant increase in head-turning behaviour in the last 2 seconds before a crossing initiation in the yielding trials, in line with a ‘last-second check’ reported in observations of real-world crossings (Hassan, Geruschat, & Turano, 2005). The vehicle’s braking behaviour and stopping distance were the most important factors affecting pedestrians’ head-turning patterns during the crossing, with the least head-turning behaviour seen in the AVSB condition, compared with AVHB and HDB trials. This suggests that a closer stopping distance for the AV was associated with less confusion for the pedestrian, although this condition was also associated with the longest crossing initiation time. In contrast, the highest number of head-turnings were seen for the human-driven vehicle, which, on average, yielded about 40 m away from the participants, enabling a much faster crossing initiation. Overall, the shortest crossing initiation time (~ 1 sec) and highest head-turning behaviour were seen in the non-braking conditions, where participants crossed as quickly as the circumstances allowed. These results provide new insights about the use of VR simulators for understanding pedestrians’ crossing behaviour in response to different vehicle kinematics. They also extend our knowledge of pedestrian cues for the development of suitable sensors in future automated vehicles, which should help with providing a more seamless interaction between AVs and other road users in mixed traffic settings.

Description of the algorithms to test the horizontal jump in a computerized testing system of gross motor skills

Gross motor skills assessment is important for children, youth and adults and can be beneficial in the study and diagnosis of different health conditions. Classical tools are administered mainly by operators. A computerized system using sensors to assess the gross motor skills would enhance these tools, providing consistency of measurements, reduced human error and automated data collection. As part of a computerized system to measure gross motor skills using the KinectTM , we present the details of development of the algorithms to test the horizontal jump (HJ) skill. These algorithms were developed by translating the performance criteria into equations of the coordinates of anatomical landmarks describing an expected kinematic behaviour of relevant body parts. Testing of the algorithms showed that they were successful in correctly evaluating the performance criteria.

Joint Kinematics and Sealing Capacity Assessment of Ductile Iron Pipes under Abrupt Transverse Ground Movements

Joint kinematic behaviour, i.e., joint rotation and axial translation, can partially help pipelines to accommodate abrupt ground movements, and cause leaking if joint service limit is exceeded, even without any structural failure. Kinematic behaviour of bell-spigot jointed ductile iron (DI) pipes and its influence on joint sealing capacity under abrupt transverse ground movements are investigated in this study. Firstly, a beam-on-spring finite element analysis on joint kinematics of DI pipes is conducted, in which different fault-pipe crossing positions are implemented. Based on simulated results, a modified joint kinematic solution incorporating pipe deflection and joint shear force under different fault-pipe crossing positions is proposed. Then, a Monte Carlo simulation (MCS)-based reliability assessment procedure for joint sealing capacity is developed. Sensitivity analysis is subsequently conducted to investigate the effects of uncertainties associated with initial axial translation, soil properties, and crossing positions on the joint sealing capacity, and the effects of different deterministic solutions are compared. The proposed method allows engineers to effectively evaluate how the joint sealing capacity of DI pipes changes with consideration of uncertainties when abrupt transverse ground movements are encountered.

Design of Robotic Motion Platform utilising Continuous Contact Skating

The continuous contact-based skating technique utilises the sideways movement of the two skates while changing the orientation of the two skates simultaneously. The skates remain in contact with the surface. A mathematical model mimicking a continuous skating technique is developed to analyse the kinematic behaviour of the platform. Kinematic and dynamic equations of motion are derived for the impending non-holonomic constraints. Heuristic-based motion primitives are defined to steer the robotic platform. For the lateral movement of the platform, a creeping based motion primitive is proposed. A prototype of the robotic platform is developed with three actuated degrees of freedom – orientation of two skates and distance between them. A multibody model of the platform is also developed in MATLAB. Analytical expressions are verified to be useful using the simulation and experimental results. The robotic platform follows the desired motion profiles. However, the initial deviation has been observed in both the simulations and experiments due to the slipping of the roller skate at the contact point with the surface. The platform can be effectively used in a structured environment autonomously.

An Estimator for the Kinematic Behaviour of a Mobile Robot Subject to Large Lateral Slip

In this paper, the effects of wheel slip compensation in trajectory planning for mobile tractor-trailer robot applications are investigated. Firstly, a kinematic model of the proposed robot architecture is marked out, then an experimental campaign is done to identify if it is possible to kinematically compensate trajectories that otherwise would be subject to large lateral slip. Due to the close connection to the experimental data, the results shown are valid only for Epi.q, the prototype that is the main object of this manuscript. Nonetheless, the base concept can be usefully applied to any mobile robot subject to large lateral slip.

A Planar Parallel Device for Neurorehabilitation

The patient population needing physical rehabilitation in the upper extremity is constantly increasing. Robotic devices have the potential to address this problem, however most of the rehabilitation robots are technically advanced and mainly designed for clinical use. This paper presents the development of an affordable device for upper-limb neurorehabilitation designed for home use. The device is based on a 2-DOF five-bar parallel kinematic mechanism. The prototype has been designed so that it can be bound on one side of a table with a clamp. A kinematic optimization was performed on the length of the links of the manipulator in order to provide the optimum kinematic behaviour within the desired workspace. The mechanical structure was developed, and a 3D-printed prototype was assembled. The prototype embeds two single-point load cells to measure the force exchanged with the patient. Rehabilitation-specific control algorithms are described and tested. Finally, an experimental procedure is performed in order to validate the accuracy of the position measurements. The assessment confirms an acceptable level of performance with respect to the requirements of the application under analysis.

Volume optimization of end-clamped arches

Even if arch arised as structural system more than two thousand years ago, this structural typology is still not widely diffused and is mainly adopted when large spans have to be covered. The structural efficiency of arches primarily depends on optimal material exploitation, i.e. minimization of internal stress eccentricity that reduces structural material volume and weight. An efficient structure, under these terms, implies simple and light scaffolding, so contributing in minimizing construction costs. Although very abundant knowledge and literature on arches, there is still scope for design optimization. This study is framed within this context and deals with the structural analysis of end-clamped plane circular arches under uniformly distributed vertical load and self weight. In the first step, the analytical solution of arch static and kinematic behaviour is derived by the force method. In the second step, the arch shape is optimized, by assuming the arch volume, and thus the weight, as objective function. Finally minima of the objective function (i.e. optimal geometric shape parameters) are computed and charted in order to be used for practical purposes.