Deviation Of Position Research Articles

Evaluation of a prototype array for daily quality assurance in spot scanning proton therapy.

Quality assurance (QA) on a daily basis is an essential task in radiotherapy. In pencil beam scanning proton therapy (PBS), there is a lack of available practical QA devices for routine daily QA in comparison to conventional radiotherapy. The aim was to characterize and evaluate a prototype for the task of daily QA routine for PBS with parameters recommended by the AAPM TG 224, that is, the dose output constancy, the spot position and the distal range verification. Furthermore, a time efficient calibration method for fast and reliable daily QA routine was established for theprototype. First, a calibration routine was designed and evaluated, which characterizes the array response and allows for a conversion of the measured signal to clinically needed QA parameters. Finally, a time and resource efficient daily QA routine was developed andtested. The prototype array can distinguish spot position deviations with sub-millimeter accuracy, as well as changes in the spot size in terms of FWHM with a 2 sensitivity. The range and thus the energy can be evaluated at different depths also with sub-millimeter precision. After some training, the setup of the prototype device took roughly two minutes and the total beamtime was about one minuteon cyclotron site and five minutesfor synchrotrons. A prototype for daily QA in spot scanning proton therapy was evaluated, which features a fast and easy setup and allows for measuring relevant beam parameters, typically within less than a minute of beam time. All QA parameters as recommended by the AAPM TG 224 report can be analyzed with sufficientaccuracy.

Method for robot kinematic parameters identification based on position and orientation data obtained with laser tracker.

How to quickly and accurately identify the kinematic parameter errors is an important prerequisite for robot accuracy compensation. The laser tracker is used to measure and identify the kinematic parameters of the robot. The influence of laser tracker layout in robot pose measurement is analyzed, and the evaluation function of laser tracker layout is constructed to determine the optimal layout position. Then, the mapping relationship between the position and orientation deviation of the robot end and the deviation of each kinematic parameter is established, and the kinematic parameter identification model integrating the position and orientation information is constructed. The identification model is compared to the identification model based on position information to clarify the intrinsic reason of high accuracy. Next, aiming at the problem that the genetic algorithm is easy to prematurely converge to the local optimal solution, a hybrid genetic algorithm is constructed by introducing the simplex method to determine the optimal calibration pose set of the robot. On this basis, the results of robot kinematics parameter identification based on position measurement data, pose measurement data, and optimal calibration pose set are compared and analyzed through experiments, which verifies the effectiveness of the robot kinematics parameter identification model based on pose measurement data and optimization strategy.

A feedforward kinematic error controller with an angular positioning deviations model for backlash compensation of industrial robots

The accuracy of industrial robots, typically on the order of several millimeters, has inhibited their adoption in advanced aerospace manufacturing applications, such as robotic machining. For this reason, extensive investigations have been conducted to develop solutions to improve their accuracy. These solutions can be categorized into offline and online compensation strategies, both of which have advantages and limitations. Offline compensation has been shown to improve the accuracy of industrial robots by two to three orders of magnitude; however, the sensitivity of these solutions to environmental changes and external disturbances can degrade their performance. In contrast, online compensation, which utilizes real-time measurement and compensation, is robust to these changes; however, the performance of these solutions is limited by the causality of time, preventing them from compensating fast changing errors such as backlash. In this work, a novel kinematic modeling strategy, which models the robot’s angular positioning deviations to predict when backlash will occur, is integrated into a novel online kinematic error compensation framework to leverage the advantages of both solutions. By integrating the proposed kinematic model into the online compensation framework, backlash errors can be predicted and preemptively compensated to improve performance. The performance of the combined system was evaluated using ball bar measurements, where it was shown to improve the circularity of the ball bar motion by 25 %.

Thermal insulation enhanced by the dopant-induced phonon softening discovered in thermoelectric Heusler compounds

Suppression of phonon transports is a key requirement to achieve high thermoelectric performance, which has been often realized by doping an element to enhance the phonon scattering. However, detailed origins behind the dopant-induced low lattice thermal conductivity (κph) have not yet been comprehensively understood. Here, we demonstrate a κph reduction mechanism induced by the phonon softening in the element-doped Fe2VAl thermoelectric Heusler compounds. Inelastic X-ray scattering experiments revealed that overall optical phonons are softened with increasing Ti-doping concentration in marked contrast to the Ta-doped Fe2VAl. By means of photoelectron spectroscopy, we found that the observed phonon softening is originating from the rigid-band shift of the electronic density of states and the consequent deviation of the pseudo-gap position from the Fermi level, which causes the energetic instability of the electronic system. This instability is accompanied by the reduction of the filled bonding states, giving rise to the phonon softening. This mechanism of κph reduction caused by the close correlation between electronic and phononic systems will shed new light on achieving low-κph and thereby developing unconventional high-performance thermoelectric materials.

Evaluation of a radiological grading system for the early detection of total knee arthroplasties at risk for revision surgery

IntroductionX-rays are regularly performed after primary total knee arthroplasty (TKA). While soft tissue management and ligament tension cannot be evaluated, important information, such as inadequate component positioning and loose cement location, as well as subsequent loosening, can be detected. The aim of this study was to correlate radiological findings, referring to the radiological grading system (previously published by the same study group, henceforth abbreviated as “RGS”), with long-term outcomes and implant survival.Materials and methodsA total of 266 patients who underwent titanium-coated TKA were included. In addition to implant survival, visual analogue scale score, Tegner activity score, knee society score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index, and short form-12 score as well as range of motion were evaluated. Clinical examination as well as anterior-posterior, lateral, full-length weight bearing, and patellar view radiographs were performed pre- and postoperatively, at the 3-, 6-, and 12-month postoperative follow-ups and at the final follow-up. The radiological grading system was evaluated and correlated with long-term outcome and survivorship.ResultsThe revision-free survival rate was 88.4% at a median follow-up of 9.8 years (IQR: 9.3–10.3 years; range: 0.1–11.8 years). Revision surgery was required in 31 TKAs (11.7%). The multivariate Cox regression model showed a significant association between an RGS score ≥ 3 deviation points (DP) and an increased risk for revision (hazard ratio: 2.092; 95% CI: 1.020–4.290; p = 0.044). Moreover, the KSS for pain was significantly worse in patients with a RGS score ≥ 3 DP (median, 85 [74–92] vs. 90 [80–94]; p = 0.007).ConclusionsThis is the first study indicating that deviation in component positioning, having an inadequate long leg axis, the presence of free cement or residual bony structures on postoperative X-rays significantly correlate with TKA outcome and implant survival. Therefore RGS can be of high predicable value for the survivorship of the prosthesis.Level of evidenceLevel IV – retrospective cohort study.

Visually induced involuntary arm, head, and torso movements

We explored in 75 s long trials the effects of visually induced self-rotation and displacement (SR&D) on the horizontally extended right arm of standing subjects (N = 12). A “tool condition” was included in which subjects held a long rod. The extent of arm movement was contingent on whether the arm was extended out Freely or Pointing at a briefly proprioceptively specified target position. The results were nearly identical when subjects held the rod. Subjects in the Free conditions showed significant unintentional arm deviations, averaging 55° in the direction opposite the induced illusory self-motion. Deviations in the Pointing conditions were on average a fifth of those in the Free condition. Deviations of head and torso positions also occurred in all conditions. Total arm and head deviations were the sum of deviations of the arm and head with respect to the torso and deviations of the torso with respect to space. Pointing subjects were able to detect and correct for arm and head deviations with respect to the torso but not for the arm and head deviations with respect to space due to deviations of the torso. In all conditions, arm, head, and torso deviations began before subjects experienced SR&D. We relate our findings to being an extension of the manual following response (MFR) mechanism to influence passive arm control and arm target maintenance as well. Visual-vestibular convergence at vestibular nuclei cells and multiple cortical movement related areas can explain our results, MFR results, and classical Pass Pointing. We distinguish two Phases in the induction of SR&D. In Phase 1, the visual stimulation period prior to SR&D onset, the arm, head, and torso deviations are first apparent, circa < 1 s after stimulus begins. They are augmented at the onset of Phase 2 that starts when SR&D is first sensed. In Phase 2, reaching movements first show curved paths that are compensatory for the Coriolis forces that would be generated on the reaching arm were subjects actually physically rotating. These movement deviations are in the opposite direction to the MFR and the arm, head, and torso deviations reported here. Our results have implications for vehicle control in environments that can induce illusory self motion and displacement.

Usability of Pseudo-Haptic Feedback for Manual Precise Manipulation of Objects in Augmented Reality

Manual precise manipulation of objects is a critical skill in daily life, and Augmented Reality (AR) is increasingly used to support such tasks. In this study, we propose a system utilizing pseudo-haptic feedback to support precise manipulation for six degrees of freedom (6DOF). Two types of AR instruction interfaces were developed: Visual Deviation Instruction Interface (VDI) and Pseudo-Haptic Instruction Interface (PHI). A user study with 18 participants compared the two instruction interfaces in terms of performance and user experience. The objective measures of performance (task completion time, deviation), and the subjective measures (system usability scale, NASA Task Load Index) were collected. Results show that both instruction interfaces effectively support manual precise manipulation, achieving position deviations under 2 mm and orientation deviations under 1°. PHI outperformed VDI in speed, mental effort, physical demand, performance, perceived workload, custom user experience elements and reduction deviations of manual precise manipulation. Finally, we discuss research limitations and future directions.

Self-calibratable absolute modular rotary encoder: a theoretical feasibility study

Abstract This paper introduces a self-calibratable absolute modular rotary encoder based on the Equal Division Average (EDA) method, designed to significantly enhance measurement accuracy and simplify installation. The proposed design integrates multiple optical sensors into the encoder stator Printed Circuit Board (PCB), enabling precise absolute position measurement through the averaging of sensors data. This multi-sensor approach compensates for alignment and installation inaccuracies, which are common issues in conventional modular encoders. To validate the design and predict encoder behaviour prior to manufacturing, a theoretical modelling of virtual optical sensors is performed. Based on experimentally collected cross-calibration data from a real optical encoder, this modelling framework enables to estimate the efficiency of self-calibration algorithm with sufficient accuracy and optimize the design and performance of the encoder. The obtained results confirm that the proposed measurement system significantly reduces error margin, improving the reliability and precision of position feedback. The initial position deviation of several hundreds of arcseconds might be reduced and kept below 8 arcseconds by using two or more additional optical sensors, even with the 0.5 mm misalignment of the encoder stator.

An on-machine measurement and calibration method for incident laser error in dual-swing laser heads

The dual-swing laser head is essential for five-axis laser machining, yet its precision is greatly affected by the incident laser beam. Any positional or angular deviation in the laser can cause the focus spot position of the head to change continuously during rotation, thereby severely compromise the manufacturing performance of the head. However, the current calibration methods for the incident beam of dual-swing laser heads have issues with low accuracy and insufficient engineering applicability. This paper proposes an on-machine measurement and calibration method for incident laser error in dual-swing laser heads. An error model for the incident beam with a dual-swing laser head was established, from which the law of spot position changes caused by incident beam errors during the head's rotation was derived. Subsequently, following this law, a precision calibration method for the laser head's incident beam error was proposed, based on the theory of optical image height. Afterwards, an on-machine error measurement system was established on the dual-swing laser head, and the calibration method was verified through experiments. The results show that the use of this calibration method can improve the accuracy of the incident beam for dual-swing laser head to 0.071 mm, which is approximately 3–4 times better than traditional calibration methods, thereby significantly enhancing the manufacturing precision of the laser head.

Film hole layout optimization for multi-row film cooling plate in continuous parameter space under non-uniform inlet temperature distribution

Film cooling is an advanced external cooling technology for protecting gas turbine blades from excessive temperatures. To counteract non-uniform heat loads caused by hot streak and swirl effects at the combustion chamber outlet, fine design of film hole positions is necessary. However, the complexity due to the numerous film holes and their positional parameters presents challenges in the independent optimization of film hole positions in a continuous parameter space. This study proposed an optimization method grounded in the divide and conquer approach to address optimization for film hole layout. The film hole layout was decomposed into multiple single rows and optimized systematically by iteratively refining the single-row film hole layout along the streamwise direction using the expectation maximization algorithm. Optimized layouts for five different inlet temperature distributions were obtained using the proposed method and adiabatic wall temperature distributions were compared and analyzed for optimized and staggered layouts. Additionally, the cooling performance of the optimized layout was evaluated against the staggered layout under conjugate heat transfer conditions and the robustness of the optimized layout under various blowing ratios and peak temperature positions was tested. The results demonstrated that the proposed method can optimize the positions of 52 film holes within 0.3h, and it was generalized to various inlet temperature distributions. By enhancing lateral interactions among downstream film jets, the lifting effect of kidney vortex in the optimized layout was weakened, bringing the film jets closer to the wall and significantly increasing coolant coverage during streamwise development. Comparative analysis reveals the superior cooling performance of the optimized layout at the blowing ratio of 1.0, evidenced by a 15.1% reduction in total input heat transfer rate and a 12.3% enhancement in overall cooling efficiency relative to the staggered layout. Under conditions with blowing ratios ranging from 0.5 to 1.5 and peak temperature position deviations, the average wall temperature of the optimized layout consistently remained lower than the staggered layout, indicating the robustness of the optimized layout to variations in blowing ratio and hot streak position.

Enhancing dynamic stability of HTS maglev systems with preloading method

High temperature superconducting (HTS) bulks have strong flux pinning capabilities and are widely used in various fields. Their self-stabilizing characteristics also provide new ideas for ultra-high-speed rail transit. For HTS maglev systems, operational stability, curve negotiation and safety when subjected to external forces are very important. Due to the hysteresis effect of superconducting bulks, they do not always return to their initial positions after deviating from the levitated position in an alternative external magnetic field. In some cases, the levitation system can be destroyed. Studies have shown that preloading can enhance quasi-static levitation performance. Therefore, this paper conducts a detailed analysis of the quasi-static levitation and guidance forces of HTS bulks above a Halbach permanent magnet guideway (PMG) under conditions with and without preloading. Additionally, the dynamic responses of the HTS bulks under lateral or vertical pulsed excitations are studied, with a particular focus on the final equilibrium position offset after disturbance. The results indicate that preloading can suppress the attenuation of the levitation force, enhance the guidance performance, and raise stiffness in both lateral and vertical directions. It also effectively suppresses position deviation from disturbance and increases the maximum excitation force threshold for system instability. This study provides practical insights for HTS maglev applications.

Position Servo Control of Electromotive Valve Driven by Centralized Winding LATM Using a Kalman Filter Based Load Observer

The exhaust gas recirculation (EGR) valve plays an important role in improving engine fuel economy and reducing emissions. In order to improve the positioning accuracy and robustness of the EGR valve under uncertain dynamics and external disturbances, this paper proposes a positioning servo system design for an electromotive (EM) EGR valve based on the Kalman filter. Taking a novel valve driven by a central winding limited angle torque motor (LATM) as the object, we have fully considered the influence of the motor rotor position and load current, as well as the magnetic field saturation and cogging effect, improved the existing LTAM model, and derived accurate torque expression. The parameter uncertainty of the above internal model and the external stochastic disturbance were unified as “total disturbance”, and a Kalman filter-based observer was designed for disturbance estimations and real-time feed-forward compensation. Furthermore, using non-contact magnetic angle measurements to obtain accurate valve position information, a position control model with real-time response and high accuracy was established. Numerous simulated and experimental data show that in the presence of ± 25% plant model parameter fluctuations and random shock-type disturbances, the servo system scheme proposed in this paper achieves a maximum position deviation of 0.3 mm, a repeatability of positioning accuracy after disturbances of 0.01 mm, and a disturbance recovery time of not more than 250 ms. In addition, the above performance is insensitive to the duration of the disturbance, which demonstrates the strong robustness, high accuracy, and excellent dynamic response capability of the proposed design.

Improve the Performance of SAR Ship Detectors by Small Object Detection Strategies

Although advanced deep learning techniques have significantly improved SAR ship detection, accurately detecting small ships remains challenging due to their limited size and the few appearance and geometric clues available. In order to solve this problem, we propose several small object detection strategies. The backbone network uses space-to-depth convolution to replace stride and pooling. It reduces information loss during down-sampling. The neck integrates multiple layers of features globally and injects global and local information into different levels. It avoids the inherent information loss of traditional feature pyramid networks and strengthens the information fusion ability without significantly increasing latency. The proposed intersection-of-union considers the center distance and scale of small ships specifically. It reduces the sensitivity of intersection-of-union to positional deviations of small ships, which is helpful for training toward small ships. During training, the smaller the localization loss of small ships, the greater their localization loss gains are. By this, the supervision of small ships is strengthened in the loss function, which can make the losses more biased toward small ships. A series of experiments are conducted on two commonly used datasets, SSDD and SAR-Ship-Dataset. The experimental results show that the proposed method can detect small ships successfully and thus improve the overall performance of detectors.

Calibration of rotary axis angular positioning deviations in a six-axis robotic manipulator by using the R-Test

Prediction accuracy of the kinematic model plays a pivotal role in offline numerical compensation for three-dimensional (3D) positioning error of a six-axis robotic manipulator. In addition to the Denavit-Hartenberg (D-H) error that was typically discussed in the analogous research, this paper proposes a novel scheme to identify the bidirectional angular positioning deviations of all the rotary axes without using the commercial laser tracker. This proposed scheme employs the R-Test, which is significantly more cost-efficient than a laser tracker employed in many past works. Compared to the conventional D-H model, significantly improved prediction performance of the proposed model was experimentally investigated on three rectangular paths covering the entire workspace. Experimental results indicate that the proposed scheme reduces the residual error from 505.2 to 215.2 mm, compared to 118.8 mm with a laser tracker, while maintaining a significantly lower cost that is 1/100 of a commercial laser tracker. Uncertainty analysis also clarify that when only the D-H error parameters are identified, as in many conventional works, the angular positioning deviations can be a major uncertainty contributor to the identification of the D-H errors. The proposed scheme does not require the R-Test locations to be calibrated, and its influence on the uncertainty in the identified errors is assessed.

Development of a Novel Retinal Surgery Robot Based on Spatial Variable Remote Center-of-Motion Mechanism

Abstract This article reports the design, modeling, and experiments of a novel retinal surgery robot based on spatial variable remote center-of-motion (RCM) mechanism. The general design criteria for parallel mechanisms are proposed, and the planar five-bar mechanisms are evaluated and selected. The planar-spatial evolution process, including the parallel connection of the planar mechanism and the equivalent substitution of joints, is adopted to develop a spatial variable RCM mechanism and then the robot. The mobility and singularity of the robot are analyzed, and the forward/inverse kinematics and workspace are modeled. Dimension optimization is conducted based on a comprehensive performance indicator that characterizes the motion range of linear actuators and the global dexterity performance index of robot. The prototyped robot is fabricated and assembled, and the kinematic calibration is performed. The position error of end-effector is within 34 μm, and both the position error and deviation of the RCM point are within 23 μm. The robot is demonstrated to reach the desired position and execute the RCM motion with high precision simultaneously.

Locomotion trajectory optimization for quadruped robots with kinematic parameter calibration and compensation

It is significant to improve the locomotion trajectory accuracy of a quadruped robot for more applications. A compensation approach with kinematic parameter calibration is proposed to enhance the trajectory accuracy. The motion equation of the foot ends in coordinated gait is given. The related kinematic error model is deduced. The model for identifying the joint parameter errors is implemented via the trajectory error in the Z-direction. The trunk trajectory accuracy enhancement is facilitated by compensating the joint parameter error with joint angles as tuning variables. The performance of the methodology is validated in the simulation system by predetermining ten random sets of joint variable errors. The results indicate that both the trajectory and the attitude accuracy of the calibrated robot can be significantly improved. In practical experiments, it is shown that an error reduction rate of 80% in positional deviation and 58% in attitude error can be achieved.

Effect of human–machine interface infotainment systems and automated vehicles on driver distraction

AbstractDriver distraction is intricately linked to human behavior and cognitive ergonomics, as it explores how human engagement with various stimuli influences attention and decision‐making processes while driving. The main purpose of this study is to comprehensively explore whether using Human–Machine Interface infotainment systems in automated vehicles can affect driver distraction. To this end, driver distraction was measured by driving performance features (speed, lane position, and reaction time), behavioral features (fixation time and pupil dilation), physiological features (changes in oxyhemoglobin), and subjective assessment (NASA‐TLX workload). Twenty‐one participants equipped with an eye tracker and functional near‐infrared spectroscopy drove a driving simulator in the current investigation. The results revealed that interacting with the infotainment systems significantly affects the drivers' average speed (F2,40 = 13.60, p &lt; .0001), reaction time (F2,40 = 4.74, p = .0142), fixation time (F2,40 = 88.61, p &lt; .0001), pupil dilation (F2,28 = 3.63, p = .0356), and workload (F2,40 = 14.40, p &lt; .0001). Moreover, driving mode significantly affects drivers' speed deviation (F2,40 = 6.12, p = .0048), standard deviation of lane position (F2,40 = 10.57, p = .0002), fixation time (F2,40 = 36.71, p &lt; .0001), and workload (F2,40 = 28.08, p &lt; .0001). Drawing from the findings of this article and emphasizing human‐centric design principles, researchers and engineers can craft automotive technologies that are intuitive, effective, and safer. This is vital for mitigating driver distraction and guaranteeing the beneficial influence of automated vehicles on both road safety and the overall driving experience.

Precipitation and temperature timings underlying bioclimatic variables rearrange under climate change globally.

Modeling how climate change may affect the potential distribution of species and communities typically utilizes bioclimatic variables. Distribution predictions rely on the values of the bioclimatic variable (e.g., precipitation of the wettest quarter). However, the ecological meaning of most of these variables depends strongly on the within-year position of a specific climate period (SCP), for example, the wettest quarter of the year, which is often overlooked. Our aim was to determine how the within-year position of the SCPs would shift (SCP shift) in reaction to climate change in a global context. We calculated the deviations of the future within-year position of the SCPs relative to the reference period. We used four future time periods, four scenarios, and four CMIP6 global climate models (GCMs) to provide an ensemble of expectations regarding SCP shifts and locate the spatial hotspots of the shifts. Also, the size and frequency of the SCP shifts were subjected to linear models to evaluate the importance of the impact modeler's decision on time period, scenario, and GCM. We found ample examples of SCP shifts exceeding 2 months, with 6-month shifts being predicted as well. Many areas in the tropics are expected to experience both temperature and precipitation-related shifts, but precipitation-related shifts are abundantly predicted for the temperate and arctic zones as well. The combined shifts at the Equator reinforce the likelihood of the emergence of no-analogue climates there. The shifts become more pronounced as time and scenario progress, while GCMs could not be ranked in a clear order in this respect. For most SCPs, the modeler's decision on the GCM was the least important, while the choice of time period was typically more important than the choice of scenario. Future predictive distribution models should account for SCP shifts and incorporate the phenomenon in the modeling efforts.

Robotic Valve Turning with a Wheeled Mobile Manipulator via Hybrid Passive/Active Compliance.

This paper addresses the problems of valve-turning operation in rescue environments where a wheeled mobile manipulator (WMM) is employed, including the possible occurrence of large internal forces. Rather than attempting to obtain the exact position of the valve, this paper presents a solution to two main problems in robotic valve-turning operations: the radial position deviation between the rotation axes of the tool and the valve handle, which may cause large radial forces, and the possible axial displacement of the valve handle as the valve turns, which may lead to large axial forces. For the former problem, we designed a compliant end-effector with a tolerance of approximately 3.5° (angle) and 9.7 mm (position), and provided a hybrid passive/active compliance method. For the latter problem, a passivity-based force tracking algorithm was employed. Combining the custom-built compliant end-effector and the passivity-based control method can significantly reduce both the radial and the axial forces. Additionally, for valves with different installation types and WMMs with different configurations, we analyzed the minimum required number of actuators for valve turning. Simulation and experimental results are presented to show the effectiveness of the proposed approach.

Automatic unberthing for underactuated unmanned surface vehicle: Model-based planning and control approaches in constricted harbors

Due to limitations in maneuverability, Unmanned Surface Vehicle (USV) often struggles to achieve automatic unberthing through a single cohesive operation in constricted harbors. To address this problem, this paper proposed a novel Two-Layer Trajectory Planning Method (TL-TPM) and two Model Predictive Control (MPC) methods. Throughout the trajectory planning process, the TL-TPM considers the USV dynamic constraints along with the cumulative risk in viable areas. It incorporates the residual velocity and yaw angle deviation from the backward phase to derive the USV’s retreating trajectory and optimizes sailing time in the forward phase for a smooth forward trajectory, forming a complete automatic unberthing trajectory. The Efficiency-Priority MPC (EP-MPC) and Accuracy-Priority MPC (AP-MPC) are designed for trajectory tracking, considering tracking positional deviations, yaw angle deviations and surge force variations. The proposed EP-MPC demonstrates high computational efficiency and robustness, while AP-MPC shows superior control accuracy under various environmental disturbances. Extensive simulations validate the effectiveness of these methods in achieving automatic unberthing under wind and current impacts.