Power Train Research Articles

Is strength and power training targeting hip and knee muscles superior to strength training in individuals with patellofemoral pain? Proof of concept study

The purpose was to determine whether the benefits of a muscle strength and power training program are superior to those achieved with muscle strength training alone in people with patellofemoral pain (PFP). Thirty-seven individuals with PFP (25.86 ± 7.62 years) were randomly assigned to a strength and power training group (n = 18) or strength training group (n = 19). Primary outcomes were pain intensity and physical functioning. Secondary outcomes were kinesiophobia, quality of life, maximal isometric torque and rate of torque development of the hip and knee and self-perception of recovery. Primary outcomes were measured at baseline, after six weeks, after 12 weeks and at three, six- and 12-months follow-ups. Secondary outcomes were measured at baseline and after 12 weeks. The significance level was 0.05. After interventions, no significant differences were found between groups for primary or secondary outcomes. No difference between groups were found for pain or physical functioning at the other assessment times. Results of this study indicated that addition of power exercises to strength training for hip and knee muscles did not result in superior benefits compared to strength training alone.

From Ground Up: Increasing Pitching Velocity through Lower-Limb Training

Pitching velocity is a crucial factor in effective baseball pitching performance. Upper-body-focused training is prevalent in baseball training to increase pitching velocity. However, significant pitchers, including youth league baseball players, suffer from upper body injuries due to the heavy training load of the throwing arm. This article emphasizes lower-body training to increase baseball pitching velocity. Three step-by-step recommended activities, with accompanying research support, include power training in the lower limbs, exploring and maintaining optimized stride length, and timing and mechanics of pitching sequences. The suggested lower body focused training will be beneficial in increasing pitching velocity and reducing the risk of injuries in the throwing arm. These recommendations are crucial for young baseball players, youth baseball coaches, strength coaches, and parents who aim to improve pitching performance while addressing concerns about overtraining and injury prevention.

Impact of rigorous muscle strength and power training on mobility among individuals with hip fractures: A randomized controlled trial

Patient’s mobility is not restored to pre-fracture levels until two years following a fractured hip. A persistent weakness in the muscles on the fractured leg may contribute to mobility limitations. A randomized controlled trial was conducted on individuals with hip fractures aged 60-85 to examine the effect of strength and power training twice a week on mobility. A random assignment was made between a 46-person intervention group and a 40 person control group. Over a period of twelve weeks, strength training was conducted twice per week under supervision. All measurements were conducted by a blinded measurer. We assessed mobility by timing the time it takes to climb stairs, get up from a chair, and walk. To analyze the data, we used intention-to-treat analysis. A study of efficacy was conducted for subjects who adhered to training more than 50% of the time (n = 40). 4 of the controls did not show a statistically significant improvement in mobility (p <0.001). Training had no significant effect on walking time or TUG. During the efficacy analysis, the average chair rise time for the exercise group improved by 5.4% (p < 0.005). The results of intense muscle strength and power training were observed in self-reported improvements in mobility. Participants with higher training compliance had an improved chair rise rate.

Physical Training Methods to Improve the Physical Condition Components of Elite Taekwondo Athletes in The Kyorugi Category: A Systematic Review

Objectives. The study aimed to provide a systematic review of physical training methods to improve the physical condition components of elite taekwondo athletes in the kyorugi category. Materials and methods. An extensive literature assessment of earlier research was carried out. The objective was to examine articles published between 2020 and 2024 that describe strategies for improving the physical condition component of taekwondo athletes. The electronic search was conducted using Google Scholar, PubMed, Web of Science, and Scopus. The articles that addressed methods for enhancing physical condition through exercise were compiled. Results. Sixty publications used training approaches to enhance the physical condition component of elite taekwondo athletes in the kyorugi category. Based on the physical state that is assessed and improved, items are categorized. Among the physical training methods that can be applied in the Taekwondo category of kyorugi are plyometric training, circuit training methods, speed, agility, and quickness (SAQ) training; strength training, endurance training, flexibility training, reaction training, power training, coordination training, balance training, resistance training, and functional training. Conclusions. After thorough analysis, several training techniques have been shown to be effective in enhancing the physical attributes of elite taekwondo athletes in the kyorugi category. These attributes include flexibility, response, strength, power, coordination, agility, speed, balance, and VO₂max.

Design and tests of a marine current turbine in low flow velocity

Marine current energy is recognized a promising energy source due to its inherent stability and high predictability. In the past decade, several milestones have been achieved in marine current turbine (MCT) research such as MeyGen and O2. However, compared with high-velocity currents, low velocity currents are more commonly distributed worldwide, which presents new challenges. The demand for low starting velocity and high efficiency necessitates some novel structure in the design of blade, power transmission, etc. To address these issues, taking a 50W MCT as research object, this paper firstly presents the MCT design of a new fan-shaped rotor configuration, a compact non-contact magnetic coupling, a low inertial power train and hollow-cup DC generator for easier starting. Furthermore, to realize the maximum power point tracking (MPPT) and sustainable power supply, the electrical system and its control strategy were designed. The hydrodynamic performance of the fan-shaped rotor was simulated and analyzed using CFD, and a simulation model of the electrical and control systems was constructed and tested to verify the performance. Finally, the tank and sea tests were respectively conducted to validate the performance of proposed MCT. The results indicate that the proposed MCT is capable of starting at velocities around 0.2 m/s and achieving a power coefficient (Cp) exceeding 0.4, making it well-suited for providing a continuous and stable power supply in areas with low flow velocities.

The Impact Of Yoga And Power Training On Muscle Structure In Persons With Parkinson's Disease

The Impact Of Yoga And Power Training On Muscle Structure In Persons With Parkinson's Disease

Identifying Clinically Meaningful Muscle Power Enhancements and Their Functional Correlates in Hospitalized Older Patients.

This study aimed to determine the threshold of muscle power and strength enhancements that lead to functional gains after exercise intervention in an acute care unit. A total of 302 older patients (intervention: 169, control: 133) from 2 randomized clinical trials were included (mean age: 86.7 years). We measured maximal strength (1RM) and muscle power via a velocity transducer during leg press exercise at 30% and 60% of 1RM. A multicomponent exercise program, including power training, balance, and gait exercises performed over 3 to 6 consecutive days, served as the intervention. We used an anchor-based method to correlate muscle function increases with the Short Physical Performance Battery (SPPB) and gait velocity (GVT) to define clinically meaningful improvements. In the intervention group, marked differences were found in maximal power at 30% of 1RM between SPPB responders and nonresponders (relative 83.5% vs 34.8%; absolute 33.0 vs 12.8 W; p < .05) and at 60% of 1RM (relative 61.1% vs 22.4%; p < .05). GVT responders demonstrated significantly greater improvements in both relative and absolute maximal power than nonresponders at both 30% and 60% of 1RM (p < .05), as well as greater absolute 1RM gains (21.2 vs 15.2kg, p < .05). Clinically meaningful improvements for muscle power based on SPPB and GVT ranged from 30.2% to 48.7%, whereas for 1RM, it was 8.2% based on GVT. Muscle power gains were most notable in patients with improvements in the SPPB and GVT, highlighting the critical role of muscle power in functional recovery in these patients.

POWER training improves officer autonomic health, mindfulness and social connection

POWER training improves officer autonomic health, mindfulness and social connection

Dynamic modeling, clutch parameter adaptation, and control of automatic transmission for tracked vehicles

In this study, a novel TCU control structure and algorithms including also dynamic model of the transmission will perform the gear shifting of automatic transmissions used in tracked military vehicles are designed. In case of inherent wear of the clutches, the clutch parameters are estimated by means of an adaptation algorithm that uses only the information from the transmission input and output speed sensors. These estimated clutch parameters are used in clutch torque calculation is utilized by control algorithms. For the clutch speed control in the inertia phase, a PID control structure with a negative feedforward term that cancels the nonlinearities of the system is proposed. The feedforward term utilizes the estimated wear clutch coefficients in the calculation of friction coefficients. The parameters of the PID controller are optimized by a genetic algorithm. The designed all structure are firstly tested on a MATLAB/Simulink power train simulation model, and then tested using a unique transmission on a transmission dynamometer test bench to examine its suitability for real transmission scenarios. The performances of proposed PID control and a backstepping nonlinear controller that we constructed for the tracked vehicles are compared with and without clutch wear. Maximum tracking error is decreased by 98% with proposed adaptive PID control structure with nonlinear feedforward term compare to backstepping controller. In the case of clutch wear, the back-stepping control exists in the literature has been found to result in oscillation. By updating the estimated friction coefficient from adaptation algorithm, in the backstepping controller, it is concluded that these oscillations can be eliminated. Additionally, on-off solenoid valves, are widely used, are known to cause torque interruptions and jerks during gear shifting. It has been observed the control structure presented in this study reduced the jerks by one quarter.

The Importance of Physical Fitness Parameters in Rhythmic Gymnastics: A Scoping Review.

This scoping review presents an overview of physical fitness parameters in rhythmic gymnastics as well as the association of fitness with gymnasts' performance, competitive level, and age. PubMed, Scopus, and Sport Discus databases were searched. Of the 586 records retrieved, 41 studies met the inclusion criteria (n = 1915 participants). The included studies examined flexibility, aerobic capacity, muscle power, muscle endurance, muscle strength, sprint speed, agility, balance, and coordination. Performance was associated with flexibility, aerobic capacity, lower-limb muscle power, agility, muscular endurance, balance, and coordination from a young age. Flexibility, aerobic capacity, and muscle power were, in general, higher in high-level gymnasts than in low-level gymnasts or controls. Older rhythmic gymnasts demonstrated higher scores than the younger ones in flexibility, aerobic capacity, balance, and sport-specific coordination but not in muscle endurance, while some studies reported a decline in muscle power with age. Supplementary physical fitness training improved all physical abilities irrespective of the gymnasts' level. Rhythmic gymnastics training alone improved muscle power, agility, speed, muscular endurance, and balance to a lesser extent than targeted fitness training. Muscular strength, speed, and agility are largely under-researched in rhythmic gymnastics. Emphasis should be given to targeted strength and power training due to the high mechanical loads placed on skeletally immature athletes.

Modelling of Vehicle Longitudinal Dynamics for Speed Control

Longitudinal dynamics control is one of the essential tasks for an autonomous vehicle, where it deals with speed regulation to ensure smooth and safe operations. To design a good controller, a simple yet reliable mathematical model is needed so that it can be used as a plant and to tune the controller. Although there are many types of mathematical models available in the literature, finding the right one for control application is essential. The model cannot be too complex and can be too simple. Thus, the main objective of this work is to derive a simple yet reliable vehicle longitudinal model so that it can be used as a simulation plant in MATLAB Simulink to test or tune various types of control algorithm's performance. The model consists of three main parts which are the vehicle body dynamics, simplified power train dynamic, and braking dynamic. To validate the reliability of the model, standard urban drive cycles will be used as a reference speed and a hierarchical PID control structure with inverse plant model is used to control the pedal inputs replacing the driver in simulation environment. Results show that the controller managed to track the drive cycle with an acceptable pedal pressing response which is between 40% throttle press and 20% brake press that in line with the normal operation of a vehicle. Although only simulation result is presented, the model can be used as a good starting point for further development and testing of different types of control algorithms for future work.

Effects of a 6-month dual-task, power-based exercise program on cognitive function, neurological and inflammatory markers in older adults: secondary analysis of a cluster randomised controlled trial.

Functional power-based exercise training can improve physical performance in older adults and cognitive training can improve measures of cognition, but their combined effects on cognition and related risk factors (neurological and inflammatory markers) remains uncertain. This 6-month cluster randomised controlled trial evaluated the effectiveness of dual-task functional power training (DT-FPT) on cognition and circulating neurological and inflammatory markers in older adults at increased falls risk, and whether intervention responses varied by apolipoprotein-E (ApoE) and brain derived neurotrophic factor (BDNF) polymorphisms. Three hundred residents aged ≥ 65 years at increased falls risk residing in 22 independent-living retirement communities, were randomised by village, to DT-FPT (n = 156, 11 villages) involving a multi-component power-based training program performed simultaneously with cognitive and/or motor tasks (45-60 min, 2/week), or a usual care control (CON) group (n = 144, 11 villages). Cognition (computerized CogState battery), inflammatory cytokines, BDNF, insulin-like growth factor-1, vascular endothelial growth factor, amyloid β (1-40) and (1-42) were assessed at baseline and 6-months. Overall, 233 (78%) participants completed the intervention and adherence averaged 50.1%. DT-FPT led to a net 0.18-0.20 SD benefit versus CON in psychomotor ability/attention and reaction time/attention (both P < 0.05). There were no significant intervention effects on circulating markers, except for a net 10.5% benefit in amyloid β (1-40) in DT-FPT versus CON (P < 0.05). Responses were not influenced by APOE or BDNF genotype. In conclusion, DT-FPT in older adults at increased falls risk can provide some cognitive benefits, but these were not related to corresponding changes in inflammatory or neurological markers or influenced by genotype. Australian New Zealand Clinical Trials Registry (ACTRN12613001161718). http://www.anzctr.org.au/ This project was funded by a grant from the National Health and Medical Research Council (NHMRC) Project (APP1046267).

How to choose mobile energy storage or fixed energy storage in high proportion renewable energy scenarios: Evidence in China

With the large-scale integration of renewable energy and changes in load characteristics, the power system is facing challenges of volatility and instability. Therefore, enhancing the safe and stable operation capability of the power system is an urgent problem that needs to be solved. Mobile energy storage can improve system flexibility, stability, and regional connectivity, and has the potential to serve as a supplement or even substitute for fixed energy storage in the future. However, there are few studies that comprehensively evaluate the operational performance and economy of fixed and mobile energy storage systems. To comprehensively evaluate the economic benefits of large-scale mobile energy storage systems, this paper constructs an overall horizontal cost model for energy storage systems that considers the power system and train transportation system. This model not only introduces the traditional concept of lifecycle cost of energy storage systems, but also considers the costs of traditional transmission lines and battery transportation. Secondly, to achieve simulation of large-scale mobile energy storage system planning and operation, this paper establishes a multi-region power planning and operation simulation (MPO) model and a battery transportation and logistics (BTL) model to accurately reflect the operation mode of fixed energy storage and mobile energy storage in the power system. Finally, taking the actual power grids and railway networks in Northeast and North China as case studies, this article provides an in-depth analysis of the technical, economic, and environmental performance of large fixed and mobile energy storage systems, and conducts a detailed comparison. The research results indicate that under high grid connection ratios (using 75% and 66% as examples), the overall cost of mobile energy storage systems continues to decrease to 1.42 CNY/kWh and 0.98 CNY/kWh. Compared to fixed energy storage at 5.45 CNY/kWh and 4.79 CNY/kWh, it has an absolute economic advantage and shows significant carbon reduction capabilities, reaching 241,800 to 1,394,600 tons. This discovery fully confirms the enormous potential and application value of mobile energy storage in high proportion renewable energy scenarios, providing strong technical support and economic analysis basis for the sustainable development of the power system.

Harmonic resonance evaluation and suppression of railway power conditioner-network-train coupling system

The coupling of railway power conditioner (RPC), network, and train will change the impedance characteristics of the existing traction power supply systems, which will lead to the unclear law of high-frequency harmonic resonance. This paper aims to study the resonance mechanism of the RPC-network train coupling system, and then solve the resonance problem of the existing traction power supply system from the perspective of reshaping the high-frequency impedance of the system. Firstly, the RPC-network-train coupling system’s dynamic node admittance matrix is established. After that, a comprehensive resonance evaluation method is proposed to obtain the resonance impact factors (RIFs) of multiple virtual impedances in the control strategy and the filtering parameters, which can realize the comparison and selection of five existing impedance reshaping strategies. To ensure the safe and stable operation of the RPC-network-train coupling system, a multi-objective sorting optimization strategy (MOSOS) considering resonance suppression, harmonics filtering, filter cost, and control system stability is proposed for the RPC based on the RIFs. Finally, the effectiveness of the proposed method is verified by the simulation result in MATLAB/Simulink and the experiment result in the StarSim hardware-in-the-loop (HIL) platform respectively.

Active Diagnostic Experimentation on Wind Turbine Blades with Vibration Measurements and Analysis

Abstract This paper deals with the key operational problems of wind turbosets, especially offshore, where vibrations are generated by rotor blades, as a consequence of erosive wear or icing. The primary causes of the imbalance of wind turbine rotors have been characterised, the observable symptoms of which include various forms of vibrations, transmitted from the turbine wheel to the bearing nodes of the power train components. Their identification was the result of an active diagnostic experiment, which actually entered the aerodynamic-mass imbalance of a turbine rotor into a wind power train, built as a small scale model. The recording of the observed monitoring parameters (vibration, aerodynamic, mechanical and electrical) made it possible to determine a set of symptoms (syndrome) of the deteriorated (entered) dynamic state of the entire wind turboset. This provides the basis for positive verification of the assumed concept and methodology of diagnostic testing, the constructed laboratory station and the measuring equipment used. For this reason, testing continued, taking into account the known and recognisable faults that most often occur during the operation of offshore wind turbosets. Transferring the results of this type of model research to full-size, real objects makes it possible to detect secondary (fatigue) damage to the elements transmitting torque from the wind turbine rotor to the generator early, especially the thrust bearings or gear wheel teeth.

Edge–cloud collaborative estimation lithium-ion battery SOH based on MEWOA-VMD and Transformer

The State of Health (SOH) of lithium-ion batteries significantly impacts the performance, safety, and reliability of the battery, making it a crucial component of the battery management system. Addressing the issues of inadequate accuracy and lack of robustness in current SOH estimation methods, this study introduces a novel methodology for estimating SOH in lithium-ion batteries. It leverages the multi-population evolution whale optimization algorithm optimized variational mode decomposition (MEWOA-VMD) in conjunction with Transformer architecture. This framework enhances the efficiency and accuracy of SOH estimation by leveraging the computational capabilities of edge devices for real-time data processing, as well as the robust data processing power and model training advantages offered by cloud computing. Specifically, MEWOA is utilized to optimize VMD parameters, enabling MEWOA-VMD to fully decompose the capacity signal of lithium-ion batteries. This results in a component showing a global attenuation trend and a set of fluctuating components that represent capacity regeneration, thereby minimizing the impact of capacity regeneration on SOH estimation. Subsequently, all components are collectively input into the Transformer, marking the first application of this method for input. To enhance convergence speed and training efficiency, the layer normalization (LN) layer within the neural network architecture is proactively advanced. Finally, various artificial neural networks are compared and validated on three publicly available datasets. Furthermore, Gaussian noise is introduced into the original data to validate robustness. To confirm the practical applicability of the proposed method, real-world vehicle data is used for SOH estimation. The results indicate that the proposed method achieves a maximum MSE of no more than 0.009% across three publicly available datasets, showcasing improved accuracy and stability in SOH estimation. The practical applicability is further validated using real-world vehicle data, proving the proposed method’s potential for application in edge cloud-based battery management systems.

Effects of an 8-Week In-Season Explosive Power Training Program on Neuromuscular Performance and Lower-Limb Asymmetries in Young Male Soccer Players.

Vasileiou, SS, Asimakidis, ND, Dalamitros, AA, and Manou, V. Effects of an 8-week in-season explosive power training program on neuromuscular performance and lower limb asymmetries in young male soccer players. J Strength Cond Res XX(X): 000-000, 2024-This study analyzed the effects of incorporating 8 weeks of twice-weekly explosive power training on neuromuscular performance and lower-limb asymmetries applied to soccer. Thirty-five young male soccer players were randomly assigned to either the experimental group (EXP: n = 18; mean age: 13.7 ± 0.8 years; height: 166.9 ± 8.4 cm; body mass: 58.5 ± 12.8 kg) or the control group (CON: n = 17; mean age: 13.7 ± 0.9 years; height: 168.8 ± 9.1 cm; body mass: 58.0 ± 11.4 kg). Before (TP1) and after the training period (TP2) neuromuscular performance (countermovement jump [CMJ], 10 and 20 m sprint times [T10 and T20], change of direction ability [COD]) and lower-limb asymmetries (single-leg CMJ [SLCMJ]) were evaluated. The asymmetry index (AI) for COD and CMJ tests was also calculated. Significant differences (from TP1 to TP2) were revealed for all the tested parameters in the EXP group (1.50-4.9%, p < 0.00 to 0.12, effect size [ES] = -0.44 to 0.27). For the CON group, T10, T20 505 for nondominant limb and SLCMJ performances for both limbs were significantly improved (0.85 to 1.5%, p < 0.00 to 0.21, ES = -0.36 to 0.37). Finally, the AI remained relatively unchanged for both tests and groups (1.28-3.33%, p = 0.162-0.521). These results indicate that adding twice-weekly explosive power training for 8 weeks can improve neuromuscular performance and reduce lower-limb asymmetries to a greater degree than soccer training alone in young male soccer players.

The effect of plyometric training (hurddle jumps), body weight training (lunges) and speed on increasing leg muscle explosive power of futsal players: a factorial experimental design

Futsal games have high intensity and dynamics that require good skills and physical conditions, one of which is leg muscle explosiveness. By doing plyometric training (hurddle jump), body-weight training (lunges), and paying attention to explosive power factors including speed as a group determinant is believed to affect the explosive power of the player's leg muscles. However, despite recognizing the importance of both training methods in improving leg muscle explosive power, there is still a lack of a thorough understanding of their combined effect on players' leg muscle explosive power during futsal play. This study aims to analyze the differences in the effect of the intervention groups of plyometric training methods and body weight training by considering the level of running speed on explosive power results. Training groups include plyometric training groups and body weight training groups, while speed is categorized as high or low. Using an experimental approach with a 2 x 2 factorial design, this study randomly selected 20 players aged 17.1 ± 0.768 years. Training was conducted in three sessions per week for approximately six weeks. Training focused on fast/explosive movements. Speed data was collected using the 30m acceleration test and the leg muscle explosiveness standing broad jump test. The data were then statistically analyzed using a two-way ANOVA at the 0.05 level of significance. The results showed that both training methods can benefit individuals with high speed (P&lt;0.05). However, leg muscle explosive power training with plyometric exercise was more effective on individuals with high speed (P&lt;0.05). As for those with low speed, plyometric exercise can provide better results (P&lt;0.05). These findings provide valuable insights for futsal coaches and instructors in designing customized training programs to improve leg muscle explosiveness. Keywords: Plyometric, Body Weight, Speed, Power

Electro-optic Q-switched Yb:YAG thin disk laser with widely continuously tunable pulse width at a stable output of over 80 W

We report an electro-optic Q-switched Yb:YAG thin disk laser with widely continuously tunable pulse width ranging from 16.4 to 432.2 ns. The tunability was achieved through a simple and convenient method by rotating both the Pockels cell and the quarter-wave plate at either identical or slightly different angles. Based on the 72-pass pump module and 224.4 W laser diode pumping source, a pulsed output of over 80 W was attained at a repetition rate of 100 kHz. The output power and output pulse train remained stable in the whole tuning range. The corresponding output power was 82.7 W and 84.4 W for the minimum and maximum pulse width, respectively. A model which was exceedingly more accurate than previous models describing the tunability of the pulse width were proposed and the simulation results of this model exhibited strong agreement with the experimental measurements.

Exploring the potential of a novel passenger transport model to study the decarbonization of the transport sector

To explore sustainability strategies in the transport sector in a holistic way, a model dedicated to passenger transportation has been created as a part of the multiregional WILIAM model (Within Limits Integrated Assessment Model). Based on system dynamics, our model increases the diversity of existing passenger transport models within Integrated Assessments Models by offering a detailed representation of the dynamics of the transition for different technologies and transport modes combining technological and behavioural changes. It calculates the energy demand, direct emissions and additional material requirements of the transport sector and can be linked to other submodules of WILIAM to study different feedback loops. Here we report the validation of the offline model and illustrate its usefulness and practical applicability. First, a Baseline transport scenario for Spain was developed and parametrized. This scenario describes the plausible evolution of the Spanish passenger transport system in the absence of ambitious environmental policies but nevertheless achieves a reduction of total direct CO2 emissions from passenger transport from 66 Mt CO2/year in 2022 to 60 Mt CO2/year in 2035, after which emissions remain constant until 2050. Subsequently, following the Avoid-Shift-Improve approach, various behavioural change measures and technological improvements were introduced. The comparison of the different modelled measures reveals that the most effective tested strategy to reduce direct emissions is the transition to battery electric power trains for cars, buses, and motorcycles, however at the cost of the highest material requirements. Further work will be dedicated to the study of the implications of the link of this submodule with the rest of WILIAM.