Rolling Motion Research Articles

Design and dynamics analysis of three-degree-of-freedom kinematic mechanism for helicopter attitude simulation

In the context of emergency rescue helicopter flight training, where suspended motion mechanisms are crucial, this study presents the design of a suspended three-degree-of-freedom motion mechanism aimed at replicating yaw, roll, and pitch motions within the simulation cabin. The kinematic relationship between the moving platform in drive space, joint space and platform attitude is analyzed, and the Lagrangian method is used to establish the dynamic equations and solve the driving moment of the mechanism; The active branch is set to position mode to provide accurate position output, and the passive branch is set to force control mode to improve the force distribution problem of the branch and improve the overall motion coordination of the mechanism. Position control and force control complement each other to achieve force-position hybrid control, improve the stability of the motion system, optimize the dynamic performance, and provide a new idea for the design of this type of spatial redundant drive mechanism.

Electricity Driven Behavior and Self-Cleaning Property of Droplets on Superhydrophobic Anti-pollution Flashover Coating.

The potential of superhydrophobic coatings for anti-pollution flashover should be further explored, focusing on droplet electrical behavior on surfaces. In this study, the electrically driven behavior of droplets on a horizontal superhydrophobic surface was experimentally examined. The characteristics of this behavior were compared and analyzed relative to RTV (room temperature vulcanized silicone rubber). The findings indicate that droplets exhibit a propensity to undergo a rolling motion in the direction of the electric field on superhydrophobic surfaces. The electric field strength at the critical motion state of droplets on the superhydrophobic surface is observed to decrease with an increase in the water contact angle (WCA) of the surface. Moreover, it exhibits a distinct volume effect whereby the electric field strength initially decreases and then increases as the droplet's volume increases. The distribution of the electric field around droplets on a superhydrophobic surface was simulated, and volume effect analysis was conducted on the electric propulsion of the droplet. Electric propulsion of water droplets can remove pollutants along their path, enhancing anti-pollution capabilities on superhydrophobic surfaces in power systems.

The effects of a 6 week rolling and dynamic movement training intervention on tissue hardness, pain pressure threshold, knee range of motion and muscular strength

ABSTRACT Foam Roller (FR) intervention is popular in sports and rehabilitation settings. Recently, we showed that conventional FR (FR_rolling) as well as compression of the target muscle (knee extensors) during joint movement using FR (FR_KM) have similar acute changes. The present study aimed to expand on these findings and compare the effects of a 6-week FR_rolling and FR_KM intervention on the passive and active properties of knee extensors. The participants were 36 healthy male university students (21.9 ± 1.1 years) who were randomly assigned to either controls, FR_rolling, or FR_KM. An intervention per session of 180-sec was performed 3-time/week for 6 weeks in both FR_rolling and FR_KM groups. Measurements were tissue hardness, pain pressure threshold (PPT) of knee extensors, knee flexion ROM, maximal voluntary isometric and concentric contraction before and after the intervention. PPT and knee flexion ROM were significantly increased in the FR_rolling and FR_KM groups, with no significant differences between the two groups. No significant changes were observed in tissue hardness, and muscle strength in all groups. Long-term interventions with FR_rolling and FR_KM could effectively increase knee flexion ROM and PPT similarly. Therefore, if difficulties from trunk stabilization or rolling during the FR-rolling occur, a simpler approach could be sustained through the FR_KM.

Safety and efficacy of ultrasonic bone scalpel compared with a high-speed drill in spinal surgery: our experience in sixty cases.

In this study, we aimed to evaluate the effectiveness and safety of UBS (Ultrasonic Bone Scalpel) and HSD (High-speed drill) for performing anterior or posterior decompressions in patients with pathologies in cervical and lumbar regions. Between October 2022 and June 2024, 60 patients underwent surgery in which a UBS (Sonopet UST-2001; Stryker Neuro Spine ENT, MI, USA) and High-speed Midas Rex MR8 (Medtronic, Fort Worth, TX, USA) drill was used. Informed consent was obtained from all patients. The study included 27 men and 33 women with a mean age of 59,5 ± 14.6 years (range: 28-85). The following patient data were recorded: preoperative and postoperative JOA scores, intraoperative blood loss, and operative time for decompression in lumbar and cervical region. In UBS group, the mean intraoperative blood loss was 166.0 ± 64.3ml. The mean preoperative and postoperative JOA scores were 4.5 ± 1.0 and 8.6 ± 1.8 and the mean postoperative follow-up duration was 6.1 ± 4.4 months in UBS group. The mean intraoperative blood loss was 221.2 ± 93.4ml in HSD group. The mean preoperative and postoperative JOA scores were 5.2 ± 1.1 and 8.2 ± 1.2 in HSD group. In the HSD group, the blood loss (BL) value was significantly higher (p < 0.05) compared to the UBS group. The preoperative/postoperative JOA score improvement in the UBS group was significantly higher (p < 0.05) than in the HSD group. The UBS can be safely used in spinal surgery. It reduces intraoperative blood loss and provide better clinical improvement. Authors would like to emphasize that the UBS resects the bone with oscillatory movements rather than rolling motions and this mechanism of action is important in reducing the risk of dura mater injury.

Intelligent prediction algorithm of ship roll and pitch motion based on SSA- optimized BiLSTM network

Intelligent prediction algorithm of ship roll and pitch motion based on SSA- optimized BiLSTM network

Investigating the dynamic behavior of marine gear transmission system considering ship rolling motion

Investigating the dynamic behavior of marine gear transmission system considering ship rolling motion

Automatic compensation of the mill roll eccentricity in terms of limited speed of hydraulic compression devices

Automatic compensation of the mill roll eccentricity in terms of limited speed of hydraulic compression devices Print EmailUser Rating: / 0 PoorBest Category: Content №1 2025 Last Updated on 25 February 2025 Published on 30 November -0001 Hits: 11 Twitter SocButtons v1.4 Authors: O.Boyko, orcid.org/0000-0002-9714-2843, Dnipro University of Technology, Dnipro, Ukraine, e-mail: boiko.o.o@nmu.one V.Kuvaiev, orcid.org/0000-0001-6329-071X, Dnipro University of Technology, Dnipro, Ukraine, e-mail: kuvaiev.v.m@nmu.one O.Potap*, orcid.org/0000-0001-8643-0228, Ukrainian State University of Science and Technology, Dnipro, Ukraine, e-mail: oepotap@gmail.com M.Potap, orcid.org/0009-0000-1116-6020, Ukrainian State University of Science and Technology, Dnipro, Ukraine, e-mail: mikepotap7.5.99@gmail.com M.Rybalchenko, orcid.org/0000-0001-5162-5201, Ukrainian State University of Science and Technology, Dnipro, Ukraine, e-mail: m.o.rybalchenko@ust.edu.ua * Corresponding author e-mail: oepotap@gmail.com повний текст / full article Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu. 2025, (1): 082 - 089 https://doi.org/10.33271/nvngu/2025-1/082 Abstract: Purpose. To reduce deviation of vertical dimension (thickness) of rolled products from the specified value by enhancing the accuracy and shortening the setup time of an eccentricity compensation subsystem of mill rolls based on substantiation of an eccentricity compensation method. This method is based on an active search algorithm to determine the actual eccentricity parameters in real time, taking into account the actual response time of hydraulic compression devices (HCD) and investigating its effectiveness through simulation computer modelling. Methodology. The research was based on the analytical determination of the frequency characteristics of the AGC system in sheet metal rolling, considering the actual response time of HCD of a rolling mill as well as a comprehensive model of a rolling process in a quarto mill with rolling movement and an automatic thickness control system (ATCS) that compensates for eccentricity. The study was conducted by comparing the results of computer simulation modelling of the improved ATCS, whose algorithm took into account the HCD response time, with the performance indicators of the previous system, which did not consider this factor. Findings. It has been established that under the AGC thickness control conditions, the measured amplitude of a variable component of thickness does not match the amplitude of eccentricity due to the finite response time of HCD. The frequency characteristics of the AGC system have been determined analytically, taking into account the actual response time of HPD in a rolling mill. An improved procedure for determining the actual eccentricity amplitude in real time has been substantiated, which involves a temporary reduction in the HCD speed within the initial rolling section. A structure for an automated control system has been proposed for practical implementation of this procedure. It has been demonstrated that the proposed solutions allow for a threefold reduction in thickness variations caused by eccentricity compared to the corresponding performance indicators of the known eccentricity compensation systems with the AGC thickness control. Originality. The influence of the HCD response time on the accuracy of AGC thickness control systems for rolled products has been established. An approximate linear relationship has been identified between the ratio of the amplitude of thickness fluctuations caused by eccentricity and the amplitude of roll gap fluctuations relative to the roll speed and HCD response time under the AGC algorithm thickness control conditions. The improved procedure for determining the actual eccentricity amplitude in real time has been substantiated. Practical value. The effectiveness is substantiated of implementing an improved active search algorithm for determining the eccentricity parameters of mill rolls under the limited HCD response conditions in real time. This approach allows for a threefold reduction in the sheet thickness variability caused by roll eccentricity compared to the performance indicators of the known AGC thickness control systems, thereby ensuring the production of high-precision rolled products in Ukrainian sheet rolling mills.

Hybrid A*-Guided Model Predictive Path Integral Control for Robust Navigation in Rough Terrains

Navigating rough terrains requires a robust path planning algorithm that accounts for the physical properties of the environment to maintain stability and ensure safety. This article proposes the Hybrid A*-guided Model Predictive Path Integral (MPPI) algorithm augmented with traversability estimation to address the challenges of path planning on uneven terrains. The traversability estimation process quantifies surface characteristics, such as slope and roughness to identify traversable regions. Using this information, the Hybrid A* algorithm computes paths that minimize surface irregularities and prioritize regions with lower gradients, thereby enhancing stability and reducing dynamic disturbances. These computed paths are then used to define the mean control input for the MPPI algorithm, which performs localized optimization while adhering to the terrain-aware trajectory. By integrating terrain-aware guidance through the Hybrid A* algorithm with the MPPI, the proposed methodology automates the selection of the appropriate mean control input and enhances control performance by explicitly incorporating terrain properties into the planning process. Experimental results demonstrate the ability of the algorithm to navigate complex terrains with reduced roll and pitch motions, contributing to improved stability and performance.

Constrained Nonlinear MPC with Rudder-Roll Stabilization for Integrated Path Following and Collision Avoidance in Underactuated Surface Vessels

This study develops a constrained nonlinear model predictive control (NMPC) framework, integrating rudder roll stabilization to address coupled path-following and collision avoidance challenges for underactuated surface vessels (USVs). The compact state-space model integrates both navigational states and roll dynamics through augmentation, facilitating real-time optimization of the trade-off between safety margins for roll movements and path-following accuracy. Given that excessive roll movement during obstacle avoidance in the USV path following can readily lead to USV capsizing, the NMPC approach is employed to explicitly address multiple constraints, including obstacle avoidance constraint, roll movement safety, and control input rudder angle constraints, thereby achieving precise path following for the rudder-roll reduction control system. Different from traditional methods that adhere to a pre-planned obstacle avoidance path, the proposed NMPC approach formulates obstacle avoidance as a nonlinear inequality constraint, significantly enhancing the maneuverability of the USV during obstacle avoidance. To validate the effectiveness of the proposed algorithm, the stability and optimality of the rudder-roll reduction control system are analyzed. The advantages of the proposed algorithm are ultimately demonstrated through both theoretical analysis and simulation results.

A novel constrained ring rolling process of deep-groove rings by coordinate controlling the roller motion

A novel constrained ring rolling process of deep-groove rings by coordinate controlling the roller motion

LCRBot: Load‐Carrying Rolling Robot Based on Truncated Hexahedral Tensegrity

ABSTRACTThe tensegrity robot consists of rigid compression bars and elastic tension cables, offering several advantages over traditional load‐carrying robots, including impact resistance, lightweight design, unique movement patterns, and modularity. However, research on tensegrity robots capable of carrying loads and rolling is very limited. This paper proposes a load‐carrying and rolling tensegrity robot (LCRBot) based on truncated hexahedral tensegrity structure, which offers ample load‐carrying space and the ability to perform rolling. LCRBot can achieve active deformation by elongating and shortening its internal bars. The gait control strategies of LCRBot under different numbers of actuators and rolling directions, as well as variations in different environments are investigated. The MATLAB‐based dynamic model of LCRBot is proposed and its simulation results of basic gait are consistent with the experiment. The proposed LCRBot showcases its potential for carrying sensors, power sources, and other equipment during rolling motions, making it highly valuable for research.

Hydrodynamics of a tridimensional rotational flow sieve tray with gas–liquid concurrent downflow under roll motion

Hydrodynamics of a tridimensional rotational flow sieve tray with gas–liquid concurrent downflow under roll motion

An Estimation Method for the Overthrowing Moment of Vehicles on the Car Deck of the Ro-Ro Ferry

Ensuring passenger safety and comfort is crucial for maintaining trust in sea transportation, especially as ship accidents remain a concern. One critical area for improvement is the vehicle fastening systems on Roll-On-/Roll-Off (Ro-Ro) ferries, which must account for fastening techniques and vehicle positioning to prevent shifting or overturning during adverse conditions. This study calculates the shear and overturning moments acting on vehicles when a ferry experiences rolling motion due to beam waves, using numerical simulations to evaluate the impact of vehicle placement. Wave heights were adjusted to reflect operational area conditions, and vertical and lateral accelerations were derived based on vehicle dimensions, type, and enter of gravity. A case study of a Ro-Ro ferry operating on the Bira-Pamatata route revealed that Bus 2, located at the rear centreline, exhibited the highest rolling moment of 14,370 N·m, while Ayla 21, positioned at the front centreline, had the lowest moment of 1,141 N m. These results demonstrate that vehicle mass, dimension, and vertical and horizontal center of gravity significantly influence rolling and share moments.

The resistance of Traditional Phinisi Boats: an examination the effect of bilge keel length using computational fluid dynamics (CFD)

Abstract In the contemporary marine tourism industry, the necessity to convey a larger number of passengers has required that conventional vessels be both user-friendly and secure. On the other hand, traditional shipbuilders have seldom contemplated the integration of bilge keels as a compliance measure for the ship’s stability system. In this paper, the potential for an increase in resistance that may arise from the incorporation of a bilge keel into traditional Phinisi boats is discussed. A computational fluid dynamics (CFD) methodology is implemented to analyse the resistance values. This investigation endeavours to ascertain whether variations in bilge keel length in 5-degree bilge keel slope angles are influenced by varying forward velocities. By incorporating bilge keels into the Phinisi boat, the BK05-L5 model demonstrated a substantial improvement in rolling motion reduction, with a reduction of up to 76%. Moreover, the ship’s resistance increased by only an insignificant 9.5% in comparison to the model without a bilge keel. This configuration appears in the nearly even keel condition produced by the 0.25 m reduction in draft and the reduced pitch value at high speed. This study encourages the implementation of bilge keel geometry and position that has no significant effect on ship resistance to improve the operational safety and performance efficiency of traditional Phinisi boats.

Global Phase Portrait of a Rolling Motion of Ships Equation

This paper studies the global dynamics of the rolling motion of ships in random beam seas model described by the equation x¨+(2μ+δx2)x˙+ω2x-1a2x3=0,where 0<μ≪1, 0<δ<1, ω=1 and 0<a<3. We fully explain its dynamics in the Poincaré compactification of R2.

Coupling Actions Between Ship Roll Motion and Internal Sloshing with Water and LNG Inside

Coupling Actions Between Ship Roll Motion and Internal Sloshing with Water and LNG Inside

The Time-Domain Design Stress Method for Fatigue Analysis of the Reactor Pressure Vessel in Floating Nuclear Power Plants

Nuclear power technology has rapidly advanced with the growing global demand for clean energy. As one of the core components of nuclear power plants (NPPs), the design and lifespan evaluation of reactor pressure vessels (RPVs) are critically important. However, while fatigue analysis methods for RPVs in land-based NPPs are relatively well established, the application of these methods to floating nuclear power plants (FNPPs) faces great challenges. Existing analysis methods are difficult to directly apply, and no widely accepted fatigue analysis approach currently exists for this context due to the complex working conditions in marine environments. A time-domain design stress (TDDS) method is developed in this study for the fatigue analysis of RPVs in FNPPs. This method systematically analyzes the impacts of wave loads, internal pressure, and thermal effects on the fatigue life of RPVs by simplifying the wave environment into a time-domain model of roll and pitch motions and adopting the regular wave superposition techniques. This method further adjusts the initial phases of regular waves considering the uncertainty of various load combinations, and superimposes the stress components caused by regular waves with different initial phases, thermal loads, and pressure loads. Subsequently, stress history curves are analyzed using the rainflow counting method, and combined with the damage accumulation theory, the upper and lower limits of fatigue damage are obtained. The results demonstrate that compared to traditional methods in time-domain analysis, the proposed TDDS method provides greater accuracy in evaluating the fatigue life of RPVs in FNPPs, with the average error in fatigue damage values being only 0.033%. Furthermore, the TDDS method reduces analysis time by approximately 70%, which significantly improves computational performance. These findings underscore the reliability and effectiveness of this method in practical applications.

Investigation into the Motion Characteristics and Impact Loads of Buoy Water Entry Under the Influence of Combined Waves and Currents

As a crucial component in marine monitoring, meteorological observation, and navigation systems, studying the motion characteristics and impact loads of buoy water entry is vital for their long-term stability and reliability. When deployed, buoys undergo a complex motion process, including the impact of entering the water and a stable floating stage. During the water entry impact phase, the motion characteristics and impact loads involve interactions between the buoy and the water, the trajectory of motion, and dynamic water pressure, among other factors. In this paper, the VOF model is used to calculate the buoy’s water entry motion characteristics, and then the STAR-CCM+&amp;ABAQUS bidirectional fluid–structure interaction (FSI) method is used to calculate the water entry impact load of the buoy under different water surface conditions and different initial throwing conditions, considering the influence of the flow field on the structure and the influence of the structure deformation on the flow field. The study finds that under the influence of wave and current impacts, changes in wave height significantly affect the buoy’s heave motions. Under different parametric conditions, due to the specific direction of wave and current impacts, the buoy’s pitch amplitude is relatively more intense compared to its roll amplitude, yet both pitch and roll motions exhibit periodic patterns. The buoy’s pitch motion is sensitive to changes in the entry angle; even small changes in this angle result in significant differences in pitch motion. Additionally, the entry angle significantly impacts the peak vertical overload on the buoy. Instantaneous stress increases sharply at the moment of water entry, particularly at the joints between the crossplate and the upper and lower panels, and where the mast connects to the upper panel, creating peak stress concentrations. In these concentrated stress areas, as the entry speed and angle increase, the maximum equivalent stress peak at the monitoring points rises significantly.

Design of Rolling Motion for Snake-Like Robots Using Center-of-Gravity Shift

Abstract The snake-like robot can travel over environments that are difficult for wheeled mobility mechanisms. However, undulating locomotion requires high power consumption. We propose an efficient method that integrates the center-of-gravity (COG) shifting for the navigation of the robot to address the aforementioned problem. The proposed method allows the use of rolling motion with high traveling efficiency on level ground and undulating locomotion in water as well as other uneven surfaces. In this paper, we present a design method using the multi-objective genetic algorithm in terms of the traveling velocity of the robot, load, and energy consumption of the servomotor. The results of the motion design show that the COG shift motion mode was obtained as the optimal solution. It was observed that the COG shift motion with the designed parameters can achieve high traveling efficiency compared to that with conventional undulating locomotion by experiment.

Palaeoenvironmental implications and genesis of lacustrine Lower Triassic giant ooids

The sedimentary environment and mechanisms of formation of giant ooids (> 2 mm) are not well understood. Here, we use petrographical, mineralogical and geochemical data of giant ooids from the Lower Triassic Buntsandstein Formation of central Germany to develop a coherent formation model. Structural preservation of calcite crystallites in ooid cortices in combination with comparatively low strontium concentrations (< 545 μg/g) and the absence of dolomite in the cortex suggest a primary low-Mg calcite composition. Shale-normalised rare earth elements plus yttrium (REE + Y) patterns lack a pronounced heavy REE over light REE enrichment and show a positive cerium anomaly (Ce/Ce*SN = 1.9–3.9). Together with a missing yttrium anomaly and low Y/Ho ratios (< 40), these data are largely consistent with ooid formation in a lacustrine environment. Positive cerium and lanthanum anomalies further point to formation and deposition in an alkaline to hypersaline playa-lake environment. Based on our findings, a five-stage formation model is proposed. We suggest nucleus formation by microbial spheres, followed by calcite crystal nucleation on biofilm templates at the sediment–water interface, and crystal/cortex growth inside the sediment pile. The spherical ooid form is achieved by wave-induced physical rolling motion after exhumation. Ooid growth ceases when the ooid reaches a critical size (here 4 mm), depending on local hydrodynamic properties. Inhomogeneous crystal growth and the inclusion of exogenous particles lead to structural and geochemical anomalies in the ooid cortex. Results presented here have far-reaching implications for the application of REE and other trace elements as environmental proxies in ancient carbonates.