GENERALIZED CRITERIA FOR LOADING CAPACITY OF INDUSTRIAL ROBOTS

The analysis of the correspondence of the set of functional indicators of industrial robots to the criteria of criteria similarity conditions is carried out. Using the methods of the theory of dimensions, criteria for the similarity of the functional properties of carrying capacity, speed-action and dynamism of industrial robots in terms of rotational and translational degrees of mobility have been determined. The necessary set of criteria has been created and a concept has been proposed for determining the generalized criterion complexes of the load capacity for modules, aggregates and the entire structure of the robot as a whole using the method of defragmentation and averaging the corresponding criteria by degrees of mobility. The proposed performance criterion makes it possible to compare the performance of a group of robots in terms of three kinematic indicators: speed, acceleration and the range of permissible displacements. For robots of light load capacity, the technical evolution of the considered criterion complexes is presented. It is noticed that with an increase in the reach of the robot, the criterion of load-carrying capacity for all robots decreases. The developed criteria make it possible to assess the speed action and loading capacity of a robot of any design and can be used to determine the technical level of robots and identify reserves for increasing it. Key words: degrees of mobility; manipulation system; homogeneous functions; dynamic parameters

ВИКОРИСТАННЯ ОПТОВОЛОКНА ЯК СКЛАДОВОЇ ЗАГАЛЬНОГО ЗОВНІШНЬОГО ОСВІТЛЕННЯДЛЯ СТВОРЕННЯ МАКСИМАЛЬНОГО РІВНЯ ЕНЕРГОЕФЕКТИВНОСТІ

Purpose. To develop a new lighting system for children's sports complexes. The introduction of the developed technology will improve the state of illumination of outdoor sports grounds without creating light pollution and increasing additional energy-efficient costs.Methodology. The combined technique of the technology of using two types of light sources, namely: low-power LED floodlights and optical fiber with a single light source, allows you to create an energy-efficient field illumination system. The proposed solution can be used for full illumination of street children's complexes. The selection of the parameters of the lighting system was carried out on the example of a real sports and children's complex.Findings. The performed measurements of the real parameters of the existing sports ground and taking into account its geometry allowed us to calculate the light parameters of light sources, select the appropriate materials and create a complete lighting model. A new lighting technology for sports and children's complexes has been developed, the level of lighting of sports facilities has been improved without creating light pollution.Originality. For the first time, a combined technology of illumination of sports and children's playgrounds was proposed using optical fiber and LED floodlights. The introduction of the developed technology will improve the state of illumination of such structures without creating an unnecessary light load on residents who are near the site. Moreover, such lighting will not lead to an increase in additional energy costs.Practical value. Today, most outdoor sports and entertainment venues are devoid of any lighting. The proposed complex solution can be used in any existing field lighting system. It is the most efficient and electrically safe because the optical fiber does not conduct electricity, but light. The light source itself can be located remotely and protected from vandals.

Power Transformer Voiceprint Operation State Monitoring Considering Sample Unbalance

The voiceprint characteristics of transformers are closely related to the operating conditions, but there is currently a lack of effective research on the voiceprint characteristics of transformers during operation. First of all, this article collects three operating conditions of load, light load, and no load on the basis of the transformer voiceprint signal acquisition platform. Secondly, in view of the characteristics of the transformer’s voiceprint, the 50Hz frequency multiplier component amplitude is extracted to form a feature vector, which solves the problem of low utilization rate of common feature extraction information. Finally, in view of the problem of transformer voiceprint failure and sample imbalance caused by fewer abnormal samples, a pattern recognition based on the RUSBoost algorithm is proposed. The algorithm has good recognition accuracy and applicability for transformer voiceprint samples with imbalance problems. The research results provide effective support for the monitoring and identification of the mechanical condition of transformers with sample unbalanced voiceprints, and the analysis of the operating conditions can effectively eliminate the errors that may be caused by their own different operating conditions.

Association Control Based Load Balancing in Wireless Cellular Networks Using Preamble Sequences

<p>The efficient allocation and use of radio resources is crucial for achieving the maximum possible throughput and capacity in wireless networks. The conventional strongest signal-based user association in cellular networks generally considers only the strength of the signal while selecting a BS, and ignores the level of congestion or load at it. As a consequence, some BSs tend to suffer from heavy load, while their adjacent BSs may carry only light load. This load imbalance severely hampers the network from fully utilizing the network capacity and providing fair services to users. In this thesis, we investigate the applicability of the preamble code sequence, which is mainly used for cell identification, as an implicit information indicator for load balancing in cellular networks. By exploiting the high auto-correlation and low cross-correlation property among preamble sequences, we propose distributed load balancing schemes that implicitly obtain information about the load status of BSs, for intelligent association control. This enables the new users to be attached to BSs with relatively low load in the long term, alleviating the problem of non-uniform user distribution and load imbalance across the network. Extensive simulations are performed with various user densities considering throughput fair and resource fair, as the resource allocation policies in each cell. It is observed that significant improvement in minimum throughput and fair user distribution is achieved by employing our proposed schemes, and preamble sequences can be effectively used as a leverage for better cell-site selection from the viewpoint of fairness provisioning. The load of the entire system is also observed to be balanced, which consequently enhances the capacity of the network, as evidenced by the simulation results.</p>

Association Control Based Load Balancing in Wireless Cellular Networks Using Preamble Sequences

<p>The efficient allocation and use of radio resources is crucial for achieving the maximum possible throughput and capacity in wireless networks. The conventional strongest signal-based user association in cellular networks generally considers only the strength of the signal while selecting a BS, and ignores the level of congestion or load at it. As a consequence, some BSs tend to suffer from heavy load, while their adjacent BSs may carry only light load. This load imbalance severely hampers the network from fully utilizing the network capacity and providing fair services to users. In this thesis, we investigate the applicability of the preamble code sequence, which is mainly used for cell identification, as an implicit information indicator for load balancing in cellular networks. By exploiting the high auto-correlation and low cross-correlation property among preamble sequences, we propose distributed load balancing schemes that implicitly obtain information about the load status of BSs, for intelligent association control. This enables the new users to be attached to BSs with relatively low load in the long term, alleviating the problem of non-uniform user distribution and load imbalance across the network. Extensive simulations are performed with various user densities considering throughput fair and resource fair, as the resource allocation policies in each cell. It is observed that significant improvement in minimum throughput and fair user distribution is achieved by employing our proposed schemes, and preamble sequences can be effectively used as a leverage for better cell-site selection from the viewpoint of fairness provisioning. The load of the entire system is also observed to be balanced, which consequently enhances the capacity of the network, as evidenced by the simulation results.</p>

Optimized hip-knee-ankle exoskeleton assistance reduces the metabolic cost of walking with worn loads

Background Load carriage is common in a wide range of professions, but prolonged load carriage is associated with increased fatigue and overuse injuries. Exoskeletons could improve the quality of life of these professionals by reducing metabolic cost to combat fatigue and reducing muscle activity to prevent injuries. Current exoskeletons have reduced the metabolic cost of loaded walking by up to 22% relative to walking in the device with no assistance when assisting one or two joints. Greater metabolic reductions may be possible with optimized assistance of the entire leg. Methods We used human-in the-loop optimization to optimize hip-knee-ankle exoskeleton assistance with no additional load, a light load (15% of body weight), and a heavy load (30% of body weight) for three participants. All loads were applied through a weight vest with an attached waist belt. We measured metabolic cost, exoskeleton assistance, kinematics, and muscle activity. We performed Friedman’s tests to analyze trends across worn loads and paired t-tests to determine whether changes from the unassisted conditions to the assisted conditions were significant. Results Exoskeleton assistance reduced the metabolic cost of walking relative to walking in the device without assistance for all tested conditions. Exoskeleton assistance reduced the metabolic cost of walking by 48% with no load (p = 0.05), 41% with the light load (p = 0.01), and 43% with the heavy load (p = 0.04). The smaller metabolic reduction with the light load may be due to insufficient participant training or lack of optimizer convergence. The total applied positive power was similar for all tested conditions, and the positive knee power decreased slightly as load increased. Optimized torque timing parameters were consistent across participants and load conditions while optimized magnitude parameters varied. Conclusions Whole-leg exoskeleton assistance can reduce the metabolic cost of walking while carrying a range of loads. The consistent optimized timing parameters across participants and conditions suggest that metabolic cost reductions are sensitive to torque timing. The variable torque magnitude parameters could imply that torque magnitude should be customized to the individual, or that there is a range of useful torque magnitudes. Future work should test whether applying the load to the exoskeleton rather than the person’s torso results in larger benefits.