Changes In Torque Research Articles

Efficacy of planned moderate to severe torque changes in maxillary central incisors with the Invisalign appliance: A retrospective investigation

This study aimed to investigate whether there was a difference between the planned and achieved lingual root torque of the maxillary central incisors in patients treated with an initial series of Invisalign (Align Technology, Santa Clara, Calif) aligners in which>10° change in the inclination of these teeth was prescribed via the ClinCheck facility. The pretreatment, planned, and the digital models after wear of the initial series of aligners regarding adult patients who satisfied selection criteria and were treated using the Invisalign appliance were measured using the Geomagic Control X software (version 2017.0.3; 3D systems, Rock Hill, SC). A sample of 63 patients with 126 maxillary central incisors satisfied the inclusion criteria. The mean accuracy of the planned torque change of the maxillary central incisors that was achieved was 41.9%. A clinically significant shortfall (≥5°) was detected in 78.6% of the incisors, with the majority showing an underexpression between 10°-15°. Linear regression analyses indicated that weekly or biweekly wear protocols or the presence or absence of power ridges did not influence the accuracy of planned torque expression (P>0.05). The changes in torque expression with an initial series of Invisalign aligners were less than half of what was planned in patients in which at least a 10° change in lingual root torque of these teeth was prescribed. The presence of power ridges and the aligner change protocol did not appear to significantly affect the accuracy of maxillary central incisor torque expression.

Guide vane angle and reactor coolant pump performance during idling

In order to study the influence of different guide vane angle variation on performance characteristics of reactor coolant pump (RCP) during idling process, the external characteristics of RCP model with five different guide vane angles at idling process state were analyzed. Radial force characteristics and blade load characteristics of RCP were analyzed. The results show that the head and torque changes of pump with different guide vane angles in different idle period are consistent. The head of DY1model (Guide vane angle increases sharply first and then decreases gently, which convexity is large) is the highest and torque is small. The head drop rate of DY5 model (Guide vane decreases first and then increases, and the concavity is large) is the highest and torque is the largest. With the idling, the radial force of impeller and guide vane decreases gradually. The radial force of DY5 model impeller is small and the fluctuation range is weak. The radial force of DY4 model (Guide vane shows concavity change with gentle increase) impeller before idling is the largest. In the nonlinear transition of idle period, the total radial force of DY4 model is 235 N when idling for 32 s, which is nearly 30 times lower than that before idling, and the radial force decreases the most. In different idling periods, the radial force amplitude of guide vane of DY5 model is the largest, and the radial force decrease amplitude of guide vane of DY4 model is the largest in the whole idling period. The impeller blade load of DY4 and DY5 model pumps with concavity guide vane angle change law is significantly higher than that of other model pumps after the relative position of streamline is 0.6. When the relative position of the guide vane along the streamline direction is less than 0.5, the load fluctuation of the guide vane of each model pump is large. When the relative position is greater than 0.5, the blade load fluctuation is relatively small.

Reliability of Quadriceps Twitch Muscle Properties and Explosive Voluntary Contractions at Different Knee Joint Angles

ABSTRACT Background Measures that assess muscle strength and its development, either voluntarily or involuntarily, are important in the clinical and research context. The main aim of this study was to verify the interday reliability and the minimum detectable change (MDC) of the knee extensors muscles torque using evoked contractions and explosive voluntary contractions (EVC), across six different joint angles. Methods 20 participants, 16 men and 4 women (26.5 ± 6.6 years; 174.5 ± 11.1 cm; 73.7 ± 11.3 kg), participated in this study. Evoked twitch contractions and voluntary explosive contractions of the knee extensors were performed in 2 days (test-retest) at 20, 40, 70, 90, 105 and 115 degrees. Results The most reliable twitch parameters were peak torque (PT), contraction time (CT), half relaxation-time (½ time), total impulse and peak rate of torque development (RTDPeak), with coefficient of variation (CV) ranging from ~ 8% at 20° to 5% at 115° angle. It was verified that CT and ½ time become more reliable as the knee angle changed from 20 to 115 degrees, from shorter to longer muscle lengths (7.3 to 2.7% and 8.8% to 4.0%, respectively). The more reliable parameters for voluntary contraction were PT, RTD250 ms, RTDPeak and impulse250 ms (CV from around ~ 8% at 20°/115° and 5% at 70°/90°). For voluntary contractions, all measures performed at 70° angle were more reliable compared to the other angles. Conclusion It was concluded that for the knee extensor muscles, evoked twitch contractions presented greater reliability across knee angles, with lower CV values when compared to the voluntary measures for the same time windows. Specifically, for the evoked twitch contractions, angles from 70 to 115 degree proved to be highly reliable. On the other hand, for the voluntary contractions, the central angles (70 and 90 degree) were the most reliable.

Optimal position collaborative control of dual permanent magnet synchronous motor system

In order to improve the control accuracy and synchronous performance of the multi-motor control system, this paper proposes an optimal position collaborative control strategy for dual permanent magnet synchronous motor system. Firstly, based on the mathematical model of permanent magnet synchronous motor, an incremental predictive model is established to suppress constant and slow time-varying disturbances caused by changes in rotational inertia and load torque. Afterwards, the predicted compensation amount after multi-step prediction is obtained by minimizing the cost function which contains the synchronous error and tracking error simultaneously, and compensated to the given current loop in advance without changing the original dual motor system structure. Then the controllability and observability of the system are analyzed, and it can be proved that the system is asymptotically stable based on the optimal control theory. Secondly, considering the constraints such as maximum voltage and current limits, the optimal solution under the constraints is output to obtain the reference currents i q1 and i q2. Finally, it is demonstrated through the experiments that the proposed control strategy can achieve advance prediction compensation control of synchronous error, and the dynamic response speed is improved, while ensuring its steady-state performance remains unchanged.

Dexterous manipulation: differential sensitivity of manipulation and grasp forces to task requirements.

How humans coordinate digit forces to perform dexterous manipulation is not well understood. This gap is due to the use of tasks devoid of dexterity requirements and/or the use of analytical techniques that cannot isolate the roles that digit forces play in preventing object slip and controlling object position and orientation (pose). In our recent work, we used a dexterous manipulation task and decomposed digit forces into FG, the internal force that prevents object slip, and FM, the force responsible for object pose control. Unlike FG, FM was modulated from object lift onset to hold, suggesting their different sensitivity to sensory feedback acquired during object lift. However, the extent to which FG and FM can be controlled independently remains to be determined. Importantly, how FG and FM change as a function of object property is mathematically indeterminate and therefore requires active modulation. To address this gap, we systematically changed either object mass or external torque. The FM normal component responsible for object orientation control was modulated to changes in object torque but not mass. In contrast, FG was distinctly modulated to changes in object mass and torque. These findings point to a differential sensitivity of FG and FM to task requirements and provide novel insights into the neural control of dexterous manipulation. Importantly, our results indicate that the proposed digit force decomposition has the potential to capture important differences in how sensory inputs are processed and integrated to simultaneously ensure grasp stability and dexterous object pose control.NEW & NOTEWORTHY Successful dexterous object manipulation requires simultaneous prevention of object slip and object pose control. How these two task goals are attained can be investigated by decomposing digit forces into grasp and manipulation forces, respectively. We found that these forces were characterized by differential sensitivity to changes in object properties (mass and torque). This finding suggests the involvement of distinct sensorimotor mechanisms that, combined, simultaneously ensure grasp stability and dexterous control of object pose.

A high-speed gear reshaping method for electric vehicles combining the effects of input torque and speed variation.

In this study, we introduce an optimization method for high-speed gear trimming in electric vehicles, focusing on variations in input torque and speed. This approach is designed to aid in vibration suppression in electric vehicle gears. We initially use Tooth Contact Analysis (TCA) and Loaded Tooth Contact Analysis (LTCA) to investigate meshing point localization, considering changes in gear tooth surface and deformations due to load. Based on impact mechanics theory, we then derive a formula for the maximum impact force. A 12-degree-of-freedom bending-torsion-axis coupled dynamic model for the helical gear drive in the gearbox's input stage is developed using the centralized mass method, allowing for an extensive examination of high-speed gear vibration characteristics. Through a genetic algorithm, we optimize the tooth profile and tooth flank parabolic modification coefficients, resulting in optimal vibration-suppressing tooth surfaces. Experimental results under various input torques and speeds demonstrate that the overall vibration amplitude is stable and lower than that of conventional gear shaping methods. Specifically, the root mean square of vibration acceleration along the meshing line under different conditions is 58.02 m/s2 and 20.33 m/s2, respectively. The vibration acceleration in the direction of the meshing line is 20.33 m/s2 and 20.02 m/s2 under varying torques and speeds, with 20.33 m/s2 being the lowest. Furthermore, the average magnitude of the meshing impact force is significantly reduced to 5015.2. This high-speed gear reshaping method not only enhances gear dynamics and reliability by considering changes in input torque and speed but also effectively reduces vibration in electric vehicle gear systems. The study provides valuable insights and methodologies for the design and optimization of electric vehicle gears, focusing on comprehensive improvement in dynamic performance.

Hamstrings Hypertrophy Is Specific to the Training Exercise: Nordic Hamstring versus Lengthened State Eccentric Training.

The hamstring muscles play a crucial role in sprint running but are also highly susceptible to strain injuries, particularly within the biceps femoris long head (BFlh). This study compared the adaptations in muscle size and strength of the knee flexors, as well as BFlh muscle and aponeurosis size, after two eccentrically focused knee flexion training regimes: Nordic hamstring training (NHT) vs lengthened state eccentric training (LSET, isoinertial weight stack resistance in an accentuated hip-flexed position) vs habitual activity (no training controls: CON). Forty-two healthy young males completed 34 sessions of NHT or LSET over 12 wk or served as CON ( n = 14/group). Magnetic resonance imaging-measured muscle volume of seven individual knee flexors and BFlh aponeurosis area, and maximum knee flexion torque during eccentric, concentric, and isometric contractions were assessed pre- and post-training. LSET induced greater increases in hamstrings (+18% vs +11%) and BFlh (+19% vs +5%) muscle volumes and BFlh aponeurosis area (+9% vs +3%) than NHT (all P ≤ 0.001), with no changes after CON. There were distinctly different patterns of hypertrophy between the two training regimes, largely due to the functional role of the muscles; LSET was more effective for increasing the size of knee flexors that also extend the hip (2.2-fold vs NHT), whereas NHT increased the size of knee flexors that do not extend the hip (1.9-fold vs LSET; both P ≤ 0.001). Changes in maximum eccentric torque differed only between LSET and CON (+17% vs +4%; P = 0.009), with NHT (+11%) inbetween. These results suggest that LSET is superior to NHT in inducing overall hamstrings and BFlh hypertrophy, potentially contributing to better sprint performance improvements and protection against hamstring strain injuries than NHT.

Eccentric Muscle Strengthening Using Maximal Contractions Is Deleterious in Knee Osteoarthritis: A Randomized Clinical Trial.

Objectives: To show the superiority of eccentric versus concentric strengthening in terms of improving quadriceps strength in knee osteoarthritis (OA), a randomized controlled study was conducted to perform 12 sessions of either eccentric or concentric isokinetic muscle strengthening over 6 weeks. Methods: We recruited males and females, aged between 40 and 70 years, with predominantly unilateral femorotibial OA. Exclusion criteria were having a prosthesis, inflammatory arthritis or flare-up of OA, symptomatic patellofemoral OA, cardiovascular or pulmonary disease that could be a contraindication to the study treatment, and any pathology that could cause muscle weakness. The primary endpoint was the between-group difference in change in maximum concentric isokinetic knee extension peak torque (PT) at 60°/s on the OA side at 6 weeks. Secondary endpoints were between-group difference in change in concentric hamstring PT at 60°/s; eccentric quadriceps and hamstring PT at 30°/s; 10 m and 200 m walking speeds; pain and functional status (WOMAC score) at 6 weeks and 6 months. Results: The sample consisted of 11 females and 27 males, with a mean age of 57.7 ± 7.52 years and a body mass index (BMI) of 25.95 ± 3.93 kg/m2. Quadriceps strength increased more at 6 weeks in the concentric than the eccentric group with no statistical difference. There was a rate of 25% major adverse events in the eccentric group. Conclusions: Eccentric training resulted in a smaller improvement in quadriceps strength than concentric training and was associated with a high risk of muscle injury, particularly to the hamstring muscles.

DC motor speed control using boost converter DC-DC chopper type based on the PID controller

Abstract The boost converter with PID-based control is designed to be able to control the speed of the DC motor. In particular, the boost converter based on the PID able to produce output from the control process that is more intelligent, efficient and effective in maintaining the stability of the DC motor rotation. From the results, It can shows the difference and effect of output when using only boost converter and when implemented with PID control. The motor control is carried out with different torque conditions. The expected result is controlling the motor speed by the boost converter based on the PID and its performance at the time of starting as well as to changes in the reference speed of rotation and load according to the set point. From the experiment, it was found that the boost converter can increase the voltage according to changes in load torque and PID control can eliminate overshoot on the system and can reach the reference speed quickly, it only takes 1 second. Based on the data analysis that has been conducted, it can be concluded that the boost converter with PID controller functions quite well to regulate the DC motor speed to remain at the reference speed.

An Adaptive Discrete Integral Terminal Sliding Mode Control Method for a Two-Joint Manipulator

In response to the trajectory tracking control problem of manipulators under measurement disturbances, a novel multi-input multi-output discrete integral terminal sliding mode control scheme is proposed. Initially, this scheme establishes a dynamic model of a two-joint manipulator based on the Lagrangian dynamics analysis method. Subsequently, a discrete integral terminal sliding mode control law based on the dynamic model of the two joints is designed, incorporating delayed estimation of unknown disturbances and discretization errors in the manipulator system. To enhance the trajectory tracking accuracy of the control scheme and suppress the impact of sliding mode chattering on the manipulator system, an adaptive switching term is introduced into the discrete integral terminal sliding mode control law. The paper derives an adaptive discrete integral terminal sliding mode control scheme and provides stability proof for the proposed approach. Simulation experiments are conducted to compare the proposed adaptive discrete integral terminal sliding mode control scheme with classical discrete sliding mode control schemes and discrete integral terminal sliding mode control schemes. The simulation results demonstrate that the designed adaptive discrete integral terminal sliding mode control scheme maintains trajectory tracking errors within 0.004 radians for each joint of the manipulator, with minimal changes in control torque for each joint. The absolute integral of the control torque variations is calculated at 5.85×103, which is lower than other control schemes, thereby validating the effectiveness and superiority of the proposed approach.

Surface‐Level Muscle Deformation as a Correlate for Joint Torque

AbstractWearable technology excels in estimating kinematic and physiological data, but estimating biological torques remains an open challenge. Deformation of the skin above contracting muscles—surface‐level muscle deformation—has emerged as a promising signal for joint torque estimation. However, a lack of ground‐truth measures of surface‐level muscle deformation has complicated the evaluation of wearable sensors designed to measure surface‐level muscle deformation. A non‐contact methodology is proposed for ground‐truth measurement of surface‐level muscle deformation using a 2D laser profilometer. It shows how three metrics of surface‐level muscle deformation—peak radial displacement: r = 0.94 ± 0.05, surface curvature: r = 0.78 ± 0.10, surface strain: r = 0.83 ± 0.12—correlate strongly to changes in volitional elbow torque, further exploring the impact of measurement location or joint angle on these relationships. A nonlinear, lead‐lag relationship between surface‐level muscle deformation and torque is also found. The findings suggest that surface‐level muscle deformation is a promising signal for non‐invasive, real‐time estimates of torque. By standardizing measurement, the methodology can help inform the design of future wearable sensors.

Speed Control of Electric Car Using Field Oriented Controlled Switched Reluctance Motor

Nowadays, global warming caused by carbon emission threatens the lives of human beings and living organisms. The problem of reducing carbon dioxide (CO2) has become urgent. Therefore, in the vehicle world, electric vehicles (EV) are being used instead in order for reducing the fuel consumption. The using of electric motor plays a significant role in the performance of electric cars. In most recent research, the application of switched reluctance motor (SRM) can be seen to improve the performance of electric cars. Thus, this research focuses on the testing the performance of SRM. Among the many benefits of SRM, torque ripple is a drawback. For reducing the torque ripple, the closed-loop vector control is applied to motor control. In this research, field oriented control (FOC) to SRM is used for NEVERA TECH EV car. The scenarios for Speed acceleration, deceleration, and torque change are considered for the performance analysis using MATLAB/Simulink.

Dynamic Characterization of Grease-Lubricated Ball Screws

According to the lubrication characteristics of grease and lubrication mechanism, concerning the Hamrock-Dowson minimum film thickness formula, this paper analyses the trend and size of oil film thickness change of grease-lubricated ball screw sub under different aviation working conditions to identify the lubrication status. ABAQUS software is used to carry out dynamic simulation and the friction coefficient is selected according to the lubrication state and Stribeck curve to define the contact conditions to obtain the friction torque change curve and the fluctuation curve of axial velocity of the nut under different aerospace working conditions. Finally, a test bench is set up to test and calculate the friction torque of grease-lubricated ball screws to analyze the influence of different aviation working conditions on the dynamic characteristics of grease-lubricated ball screws and to investigate the reasons for the change of dynamic characteristics.

Headgear therapy in children with Class II malocclusion and the role of compliance on treatment outcome: A nine-month randomized controlled trial.

To evaluate three-dimensional movements of maxillary teeth during headgear treatment in Class II growing children, using digital analytical tools, and to determine the effects of compliance on these movements. A 9-month parallel-group randomized controlled trial was carried out on 40 children with Class II malocclusion, aged 8-12 years, half assigned to receive a cervical headgear and half to a no-treatment group, using block randomization. Subjects in the treatment group were instructed to wear the headgear for 12 hours daily and monitored using an electronic module. After 9 months, the following dental outcomes were measured: first maxillary molar distalisation, rotation, tip and torque, arch depth, and interpremolar and intermolar distances. Caregivers and participants were not blinded to group assignments, but those assessing outcomes were. Linear regression models were used to detect differences between groups and correlation coefficients to find correlations between compliance and dental outcomes. All 40 included patients were analysed. A significant difference in molar distalisation was observed between the treatment (1.2 mm) and control groups (-0.2 mm). Arch depth change was also increased to a larger extent in the treatment groups (1.3 mm vs 0.1 mm), as was the interpremolar distance (1.9 mm vs 0.4 mm). In contrast, no significant differences in molar rotation or torque change were observed. With regard to compliance, average compliance was 55%. A significant correlation was found between molar distalisation and compliance in the treatment group. Headgear therapy has significant effects on molar distalisation, arch depth, and arch width. Compliance has a significant positive effect on molar distalisation.

Research on the sealing performance of micro-nano composite magnetic powder to liquid media with different viscosities

This paper mainly focuses on the research on micro-nano composite magnetic powder (MNC-MP) sealing liquid medium. Micro-nano composite magnetic powder and temperature-resistant magnetic powder (TR-MP) were prepared, and their magnetization curves were measured. The influence of temperature on the saturation magnetization of the TR-MP was analyzed. The results show that after heat treatment at 100 °C for 10 min, the specific saturation magnetization remains unchanged at 102.55A·m2/kg. The pressure resistance performance of the MNC-MP sealing liquids of different viscosities and the pressure change of the TR-MP sealing silicone oil were studied in the static sealing test. The results show that the higher the viscosity of the MNC-MP sealing liquid, the better the sealing performance, and pressure remains stable at 120 kPa when sealing dimethyl silicone oil. The dynamic sealing test analyzed the relationship between the pressure and rotation speed of the MNC-MP sealing silicone oil. We concluded that when MNC-MP seals dimethyl silicone oil, the effective time of the seal decreases with the increase of rotational speed, and the leakage rate after failure increases as the rotational speed increases. The changes in temperature and torque of MNC-MP and TR-MP sealing silicone oil with time at different rotational speeds were compared. Compared with MNC-MP, the temperature of the TR-MP seal can be reduced by 23.74 %, and the friction torque can be reduced by 17.58 %.

An Intelligent Thermal Compensation System Using Edge Computing for Machine Tools.

This paper focuses on the use of smart manufacturing in lathe-cutting tool machines, which can experience thermal deformation during long-term processing, leading to displacement errors in the cutting head and damage to the final product. This study uses time-series thermal compensation to develop a predictive system for thermal displacement in machine tools, which is applicable in the industry using edge computing technology. Two experiments were carried out to optimize the temperature prediction models and predict the displacement of five axes at the temperature points. First, an examination is conducted to determine possible variances in time-series data. This analysis is based on the data obtained for the changes in time, speed, torque, and temperature at various locations of the machine tool. Using the viable machine-learning models determined, the study then examines various cutting settings, temperature points, and machine speeds to forecast the future five-axis displacement. Second, to verify the precision of the models created in the initial phase, other time-series models are examined and trained in the subsequent phase, and their effectiveness is compared to the models acquired in the first phase. This work also included training seven models of WNN, LSTNet, TPA-LSTM, XGBoost, BiLSTM, CNN, and GA-LSTM. The study found that the GA-LSTM model outperforms the other three best models of the LSTM, GRU, and XGBoost models with an average precision greater than 90%. Based on the analysis of training time and model precision, the study concluded that a system using LSTM, GRU, and XGBoost should be designed and applied for thermal compensation using edge devices such as the Raspberry Pi.

Robust engine slipping start control of hybrid electric vehicles with uncertainty in clutch slipping torque and change in driver demand torque

The engine slipping start (ESS) benefits parallel hybrid electric vehicles from stable ignition and emission reduction. However, inappropriate coordination between the traction motor torque and clutch slipping torque during the ESS will lead to poor smoothness of the vehicle and failed start of the engine. Uncertainty in clutch slipping torque and change in driver demand torque bring tough challenges with sluggish convergence and intensive vehicle jerk in practice. To deal with this problem, a novel two-layer model reference adaptive controller (MRAC) which contains two parallel reference models is proposed to improve robustness and convergence rate simultaneously. On one hand, uncertainties of clutch slipping torque are divided into a low-frequency part and a high-frequency part, and adaptive laws based on the output feedback are designed contrapuntally to enhance robustness. On the other hand, two parallel reference models are designed to accelerate the tracking error convergence rate without changing the reference profiles, which is generated according to the driver demand torque in real time. To test the robustness and convergence rate, the proposed two-layer MRAC is compared with the classical MRAC and proportional–integral controller under the driving scenario with uncertain clutch slipping torque and abrupt change in driver demand torque. The sensitivity with different adaptive gains and low-frequency and high-frequency uncertainties in clutch slipping torque are examined. Finally, hardware-in-the-loop experiments are performed to verify the effectiveness of the proposed two-layer MRAC.

Modeling and analysis of center-steering characteristics of variable-configuration wheel-track unmanned ground vehicle based on dynamic resistance

The variable-configuration wheel-track unmanned ground vehicle (VCWT-UGV) has both fast-moving speed on structured roads and strong passing ability on even roads. Steering dynamics analysis is the theoretical basis to ensure that the UGV can still maintain high maneuverability in complex environments. Based on the elastic-plastic deformation characteristics of the soil on the soft road, considering the dynamic changes in resistance and resistance torque caused by soil accumulation on the wheel side during the center-steering process of UGV. Firstly, MBD-EDM co-simulation is conducted to qualitatively analyze the characteristics of soil accumulation on the wheel side during the steering process. Then, based on the terramechanics characteristics of the locomotion mechanism, the kinematic characteristics of the UGV during center-steering are analyzed, and the mathematical model of soil accumulation on the wheel side is established. Furthermore, the dynamic model of the vehicle center-steering with lateral resistance changes is established, and the accuracy of the model is validated through tests. Based on a validated theoretical model, the changes in resistance, resistance torque, and power during the steering process are analyzed. Based on the analysis results, by adjusting the wheel deflection angle, the driving configuration and the motion modes of VCWT-UGV, the steering power efficiency of VCWT-UGV can reach 71.67%. The research results provide a valuable reference for the lateral dynamic modeling of general UGVs on unstructured roads.

Investigation of the Effect of Physical Ability on the Fall Mitigation Motion Using the Combination of Experiment and Simulation

The simulation of fall plays a critical role in estimating injuries caused by fall. However, implementing human fall mitigation motions on a simulator proves challenging due to the complexity and variability of fall movement. Our simulator estimates fall motion by extrapolating the motion observed in fall experiments. By incorporating actual fall motion data for the upper limbs, we enhanced the realism of the fall simulation. The application of forward dynamics control to the lower limbs allowed for the adjustment of mitigation motions, taking into account individual physical capabilities. In this study, fall simulations were conducted under the constraints of maximum joint torque and maximum torque change rate, emulating the physical capabilities of both the elderly and young adults. Our results successfully demonstrated the mitigation motion facilitated by the stance leg reduced the descent velocity of the center of mass by 0.75 m/s for elderly individuals and by 1.25 m/s for young adults, compared to a zero torque condition. This indicates that our study introduced a novel method for quantifying the impact of the lower limbs’ physical capabilities on fall velocity. Such a method represents a significant advancement in understanding how mitigation motions can influence fall injury simulations.

Final state control-based active compensation for backlash in vibration suppression of automobile powertrain

This paper proposes an effective backlash compensation method based on the final state control (FSC) for active vibration control of an automobile powertrain. Transient vibration of the powertrain caused by sudden changes in the engine torque significantly degrades the driving performance and driver comfort. In addition, the nonlinear characteristics owing to the backlash increase the adverse effects of these oscillations. To suppress the transient vibration of the powertrain, a controller is designed based on the mixed H2/H∞ control theory. Subsequently, to adjust for the vibration amplification owing to the backlash, we propose the application of a shock-reducing controller based on the FSC. Linearly decreasing the inertia weight in particle swarm optimisation (LDWPSO) was applied to the design of this controller and parameters were optimised. Finally, simulations were conducted using the control method; the controller could prevent the occurrence of shocks owing to the gear collisions and achieved smooth an acceleration.