This paper proposes a hybrid control that combines an adaptive neural network (NN)-based input shaping control (ISC) with an intelligent fuzzy logic control (FLC) for control of a tower crane. The design has an advantage as the adaptive shaper can handle the payload sway control under parameter uncertainly while the FLC provides accurate trolley and jib positioning. The most challenging operation of the crane, involving simultaneous trolley displacement, jib rotation, and payload hoisting, is investigated using a laboratory tower crane with nominal cylindrical and distributed rectangular payloads. The performance of the NN is compared with gain-scheduling lookup tables (LT) while the FLC is compared with PID. Experimental results show that the proposed NNZVD+FLC provides the highest performance with satisfactory position tracking and maintains the residual sway within ±3°. The work demonstrates that the adaptive ISC can be successfully combined with intelligent feedback controllers for effective automation of crane systems.

Publisher Correction: Robust input shaping for residual vibration suppression in overhead crane systems with suspended beams

Abstract This work demonstrates vibration suppression of a single-link flexible manipulator (SLFM) and a two-link flexible manipulator (TLFM) using input shaping. In this, inputs include pulse width modulation (PWM) duty cycle and desired angular position. The shaping of these parameters is done based on the damping ratio of the system. Vibrations due to flexibility in flexible manipulators are suppressed for better end-effector accuracy. Extra damping for the first link is achieved using a belt, and a nonrotating second link is connected to the first link to get modified single flexible link. The modified system requires fewer iterations for vibration suppression. Results are compared with a nonlinear dynamics model developed using the assumed mode method (AMM) and decoupled natural orthogonal complement (DeNOC) matrices. A simple proportional–derivative (PD) controller manages the angular position in simulations. The process of input shaping is explained in detail, showing angular position and tip deflection variations with PWM duty cycle and time. The effect of input shaping on vibration suppression is shown for a two-link flexible manipulator, i.e., when both the links are rotated.

Abstract Enhancing the energy efficiency in controlling an overhead crane during repeated rest-to-rest movements can result in significant energy savings. Moreover, it influences both maintenance expenditures and safety. This study focuses on optimizing a smooth wave command shaping profile to reduce energy usage and enhance the motion efficiency of an overhead crane. A smooth single-mode command shaper is modified to reduce the energy required during the trolley maneuver. The nonlinear equation of motion for a simple crane is derived, linearized, and then solved to determine the optimal controller performance. An extra constant is added to a smooth waveform command shaper and then optimized to enhance the required energy. Furthermore, the selectable maneuvering time feature of the smooth command shaper is utilized to further enhance the maneuver’s efficiency. The results obtained are compared with several well-known input/command shapers. The optimized command shaper profile can eliminate all residual vibrations induced and reduce energy consumption by 30% compared to the most effective unoptimized input shaper and 45% compared to the classical smooth command shaper. The performance of all shapers is numerically and experimentally validated on an experimental overhead crane.

A novel data-driven input shaping method using residual impulse vector via unscented Kalman filter

Purpose This study investigates how emotional intelligence (EI) and leadership styles influence employee performance in a Greek municipal administration. It examines three outcomes extra effort, perceived leader effectiveness and satisfaction – while situating EI as a form of non-cognitive human capital in resource-constrained settings. The analysis highlights the interplay between leadership behaviors and emotional competencies in shaping public employee engagement and organizational performance. By focusing on the Municipality of Lefkada, the study contributes to debates on human capital and organizational behavior in bureaucratically rigid, fiscally constrained contexts typical of Southern European local governments. Design/methodology/approach A structured employee survey (n = 43) was conducted using the Wong and Law Emotional Intelligence Scale (WLEIS) and Multifactor Leadership Questionnaire (MLQ-5X). To address multicollinearity, principal component analysis (PCA) reduced leadership dimensions into two orthogonal components. Regression models then assessed the effects of leadership, EI and demographics on performance outcomes. Active leadership behaviors – transformational and transactional – were positively associated with satisfaction, effectiveness and extra effort, while passive leadership was negatively related. Emotion regulation (ROE) emerged as the most influential EI factor. Models displayed high explanatory power (R2 > 0.80), underscoring leadership’s central role. Findings Overall EI levels were high, though appraisal of others’ emotions (OEA) lagged behind other competencies. Transformational leadership was strongly and positively related to employee extra effort, satisfaction and perceived effectiveness. Transactional leadership, although prevalent, was associated with weaker performance effects and even negative links to effort and effectiveness, suggesting inefficiencies in municipal management. Passive leadership consistently harmed outcomes. Among EI traits, only emotion regulation predicted higher satisfaction and discretionary effort. While EI correlated with leadership styles, regression results suggest institutional and contextual factors may overshadow individual competencies in shaping leadership behaviors in Greek local governments. Research limitations/implications The study’s small sample size (n = 43), single-case design and reliance on self-reported data limit external validity and causal inference. Although PCA mitigates multicollinearity, other diagnostic issues (e.g. heteroskedasticity and nonlinear effects) could not be fully tested. Future research should include multiple municipalities, larger samples and longitudinal or experimental designs to capture causal pathways. Despite these limitations, the findings highlight the value of integrating EI and leadership into public administration theory, suggesting that refining methodological approaches can yield more robust insights into the role of non-cognitive human capital in shaping organizational performance. Practical implications Leadership development and EI training offer practical avenues for improving public sector performance, particularly in municipalities with scarce resources and bureaucratic rigidity. Emotion regulation emerged as a trainable skill linked to employee motivation and satisfaction. Encouraging transformational and active transactional leadership while curbing passive managerial practices may improve service delivery and foster more engaged public workforces. These results support embedding non-cognitive skills into HRM systems, recruitment and leadership evaluations. Municipal administrations can thus enhance organizational resilience and citizen-oriented service delivery by integrating emotional competencies alongside traditional performance management tools. Originality/value This study bridges emotional intelligence and leadership theory within a human capital framework, advancing understanding of non-cognitive skills in public service productivity. It provides empirical evidence from a rarely examined context – a Greek island municipality – thereby enriching scholarship on Southern European local governments. Methodologically, the use of PCA-enhanced regression addresses leadership style collinearity, offering an innovative approach to small-sample public administration research. Conceptually, it frames EI as an organizational input shaping discretionary effort, satisfaction and leader effectiveness. The findings inform both academics and practitioners seeking to strengthen public sector performance through behavioral competencies.

Abstract Modern spacecrafts are often equipped with large axisymmetric flexible appendages. The coupling effect between the vibration of flexible appendages and the motion of the spacecraft’s main platform has a significant impact on the dynamics and control of the spacecraft. The displacement of flexible appendages of spacecraft, including solar panels, antennas, and space manipulators, are mainly characterized by bending deformation. The theory of Euler-Bernoulli beam is the accurate and effective modelling method, which could describe dynamic behaviours of the flexible appendages. The governing equations of the rigid-flexible coupled dynamic equations of the spacecraft were obtained by using the Lagrange’s equations in terms of general quasi-coordinates. The control strategy of the rigid-flexible coupled spacecraft system was designed to realize the attitude control of the rigid platform and suppress the residual vibration of the flexible appendages. The input shaping technique was used to suppress the displacement response of vibration in flexible appendages. Effective algorithms were designed to simulate spacecraft dynamics and control, and the accuracy of the model and control law were verified through numerical simulation. PD controller based on the input shaping technique could significantly reduce the residual vibration of the flexible appendages, which has reference significance for the overall design and controller design of the complex spacecraft system.

Efficient input shaping control for flexible structures with unscented Kalman filter

Scheduled input shaping based attitude agile control for flexible spacecraft with vibration suppression

Vibration control of flexible dynamic systems using smooth robust input shapers: theory and application

This study explores the implementation of input shaping techniques in the control of an overhead crane operating on a curved track. Input shaping is applied to mitigate oscillations during hoisting and non-hoisting maneuvers, crucial for preventing load sway and ensuring precise load handling. The crane system’s adaptability to different track profiles and its sensitivity to track parameters are thoroughly analyzed through a parametric study. Iterative learning method is employed to refine the input shaping commands over successive operations, aiming to optimize the crane’s response under varying conditions and load dynamics. Motor power analysis is conducted to evaluate the energy efficiency of the crane under different operational scenarios. The track sensitivity analysis investigates how variations in track geometry influence the effectiveness of input shaping techniques. This work highlights the benefits of integrating input shaping with iterative learning to achieve optimal performance, while also considering power aspects and system adaptability to changes.

Robust input shaping for residual vibration suppression in overhead crane systems with suspended beams

Residual vibration suppression of cooperative robot based on optimization surrogate model and input shaper control

Underactuated robotic systems are appealing for industrial use due to their reduced actuator number, which lowers energy consumption and system complexity. Underactuated systems are, however, often affected by residual vibrations. This paper addresses the challenge of generating energy-optimal trajectories while imposing theoretical null residual (and yet practical low) vibration in underactuated systems. The trajectory planning problem is cast as a constrained optimal control problem (OCP) for a two-degree-of-freedom revolute–revolute planar manipulator. The proposed method produces energy-efficient motion while limiting residual vibrations under motor torque limitations. Experiments compare the proposed trajectories to input shaping techniques (ZV, ZVD, NZV, NZVD). Results show energy savings that range from 12% to 69% with comparable and negligible residual oscillations.

This paper presents a nonlinear input shaping control scheme based on mullti-objective optimization, where both the residual vibration and the maneuvering time are minimized. Besides, to enhance the robustness of the proposed scheme, one proposes three robust methods, which are the square method, the differentiation method, and the extra insensitive method. To validate the proposed methods, a nonlinear system is used to demonstrate their control performances, where both the numerical simulations and experimental results are shown. The results show that the robustness of the proposed methods is much improved to compare with non-robust methods.

Advanced input shaping techniques for enhanced performance of bi-cable systems in simultaneous hoisting and transporting

ABSTRACTThis paper introduces a novel robust design approach aimed at reducing the sensitivity of a target metric to parameter uncertainties. Using Shapley effects from game theory as a global sensitivity proxy, we analyze a clamped‐free Euler‐Bernoulli beam with two uncertain mass positions. The first case study reduces sensitivity of the second mode frequency to mass location uncertainty and is validated experimentally on a gantry‐suspended beam. In the second case, a robust controller minimizes the Shapley effect of residual energy on mass location uncertainty. Our approach significantly reduces average residual energy compared to traditional Zero Vibration Derivative Input Shapers, as confirmed by experiments.

Mobile concrete pumping equipment is the key machinery for automation in construction. It pumps concrete through a pipeline on the large-scale flexible hydraulic manipulator, which simultaneously suffers from serious vibrations caused by the periodic external excitation forces from concrete pumping. To address this problem, a no-command input shaping technique (NIST) based on the independent modal space method (IMSM) is presented. To accurately calculate open-loop control inputs, the flexible manipulator system is transformed into modal space using the IMSM, which can derive a second-order system suitable for NIST design. A modal filter based on a flexible manipulator model is designed to estimate the coordinates. To overcome the nonlinearity of hydraulic systems, control inputs of the hydraulic actuator are applied to the flexible manipulator via a model-based force controller. The experiment is carried out on a 13-meter mobile concrete pumping equipment and the high performance of the proposed control strategy is verified.

Suppression of residual vibrations in position control of flexible systems is a challenging problem, especially in the presence of high nonlinearities or diverse operating points. Input shaping, a technique for designing shaped commands to minimize system residual vibration during point-to-point movements, is crucial. Traditional input shapers like zero-vibration and zero-vibration-and-derivative shapers, designed based on the superposition principle, perform well for linear systems but have limitations in highly nonlinear systems. This paper revisits nonlinear input shapers, including three-impulse and robust shapers, providing a comprehensive energy-based analysis. Additionally, a novel fast three-impulse shaper is proposed to improve the time-delay of traditional input shapers. The amplitudes and time locations of all designed shapers are proven in the same closed-form solution for the undamped case, suitable for analyzing sensitivity to variations in plant parameters. Demonstrations on a two-mass flexible system with nonlinear spring and damper show that the proposed fast-three shaper outperforms the two-impulse shaper in robustness, with similar performance in rise time. However, robust shapers, while slower, exhibit superior robustness as increasing impulse numbers decrease residual total energy. The effect of nonlinear damping force is demonstrated in simulations, providing suggestions for designing robust shapers for damped flexible systems.

ABSTRACTIn rest‐to‐rest maneuvers, input shapers like the double step (DS), zero vibration (ZV), and zero vibration derivative (ZVD) are widely utilized to eliminate residual vibrations in single‐mode systems. These shapers can be used to eliminate residual oscillations in multimode systems, given that the higher frequencies are odd multiples of the system's fundamental frequency. However, the natural frequencies depend on the physical properties of the system, and such ratios cannot be guaranteed. In this study, an analytical frequency modulation technique is proposed to eliminate the residual oscillations of a double pendulum using a modified single‐mode shaper. The proposed technique is based on altering the natural frequencies of the system, forcing the odd multiple ratio. This involves modifying a single‐mode double‐step (SMDS) input shaper by adding scaled state variables, first and second angles, to the original shaper. This addition allows the user to choose the first natural frequency and force the second natural frequency to be an odd multiple of the chosen frequency. To apply the proposed technique, the double pendulum nonlinear equations of motion are derived, linearized, and then solved analytically using modal analysis. The scaling parameters used to modify the natural frequencies are then solved analytically. To prove the concept, several numerical simulations with randomly selected parameters are presented and then experimentally tested on a scaled overhead crane. The numerical and experimental results demonstrate the effectiveness of the proposed technique.