Pub Date : 2025-10-01DOI: 10.1016/j.mechatronics.2025.103408
Alexander Demishkevich , Bao Thy Thai , Krzysztof Skonieczny
Lunar exploration activities around the world are driving development of low mass skid-steer rovers, for which rigid wheels with grousers are common. Wheels with slanted grousers (i.e. that span from the inner to the outer edge of the wheel surface at an angle, rather than directly across) are compared favorably in this work against V-offset shaped grousers in skid-steer point turn performance, without any reduction in slope climbing performance. Single wheel tests are conducted in GRC-1 lunar simulant with the wheels oriented along a representative slip angle corresponding to skid-steer point turning. Slanted grousers achieve positive tangent turning force, , a metric introduced to identify conditions when a wheel can sustain skid-steer point turning. The slanted grouser achieves a positive at slip ratios below 0.4 compared to as much as 0.6 for V-offset, while also only experiencing approximately half as much sinkage. On the other hand, there is little to no difference in performance in straight line driving, relevant for nominal driving and slope climbing. Full rover tests with 4 appropriately configured slanted grouser wheels validate point turn and slope climbing performance with an average skid-steer point turn slip ratio of approximately 0.35 and 0.8 for slope climbing.
{"title":"Advantages of slanted grousers for skid-steer planetary rovers with rigid wheels","authors":"Alexander Demishkevich , Bao Thy Thai , Krzysztof Skonieczny","doi":"10.1016/j.mechatronics.2025.103408","DOIUrl":"10.1016/j.mechatronics.2025.103408","url":null,"abstract":"<div><div>Lunar exploration activities around the world are driving development of low mass skid-steer rovers, for which rigid wheels with grousers are common. Wheels with slanted grousers (i.e. that span from the inner to the outer edge of the wheel surface at an angle, rather than directly across) are compared favorably in this work against V-offset shaped grousers in skid-steer point turn performance, without any reduction in slope climbing performance. Single wheel tests are conducted in GRC-1 lunar simulant with the wheels oriented along a representative slip angle corresponding to skid-steer point turning. Slanted grousers achieve positive tangent turning force, <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span>, a metric introduced to identify conditions when a wheel can sustain skid-steer point turning. The slanted grouser achieves a positive <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span> at slip ratios below 0.4 compared to as much as 0.6 for V-offset, while also only experiencing approximately half as much sinkage. On the other hand, there is little to no difference in performance in straight line driving, relevant for nominal driving and slope climbing. Full rover tests with 4 appropriately configured slanted grouser wheels validate point turn and slope climbing performance with an average skid-steer point turn slip ratio of approximately 0.35 and 0.8 for slope climbing.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"112 ","pages":"Article 103408"},"PeriodicalIF":3.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-26DOI: 10.1016/j.mechatronics.2025.103409
Pin-Chu Shih , Yun-Chi Chiang , Jun-Jie Hu , Kuan-Ting Lin , Li-Chen Fu
High-quality 3D reconstruction is essential for applications such as autonomous driving, Augmented Reality (AR)/Virtual Reality (VR), and smart cities. Traditional methods using handheld sensors often result in incomplete and misaligned models. While autonomous exploration can improve these results, it often sacrifices quality for speed. This paper proposes a novel system for high-quality 3D reconstruction of large-scale indoor environments, leveraging a mobile robot equipped with a solid-state LiDAR mounted on a 2-degree-of-freedom (2-DOF) gimbal. The gimbal provides flexible scanning capabilities to overcome field-of-view (FoV) limitations of solid-state LiDARs. To address high-frequency, real-time quality evaluation during exploration, we introduce a new concept called guard-points, which guides the robot toward areas with insufficient point cloud density. These guard-points, alongside conventional frontier-based viewpoints, enable our planner to dynamically balance exploration and reconstruction quality. This system not only controls the mobile robot to visit unknown places and areas with insufficient reconstruction quality but also facilitates high-frequency, real-time exploration path planning. This paper concludes with various simulations and real-world experiments to validate the effectiveness of our system.
{"title":"Autonomous exploration of mobile robot equipped with LiDAR for high-quality reconstruction in large-scale indoor environments","authors":"Pin-Chu Shih , Yun-Chi Chiang , Jun-Jie Hu , Kuan-Ting Lin , Li-Chen Fu","doi":"10.1016/j.mechatronics.2025.103409","DOIUrl":"10.1016/j.mechatronics.2025.103409","url":null,"abstract":"<div><div>High-quality 3D reconstruction is essential for applications such as autonomous driving, Augmented Reality (AR)/Virtual Reality (VR), and smart cities. Traditional methods using handheld sensors often result in incomplete and misaligned models. While autonomous exploration can improve these results, it often sacrifices quality for speed. This paper proposes a novel system for high-quality 3D reconstruction of large-scale indoor environments, leveraging a mobile robot equipped with a solid-state LiDAR mounted on a 2-degree-of-freedom (2-DOF) gimbal. The gimbal provides flexible scanning capabilities to overcome field-of-view (FoV) limitations of solid-state LiDARs. To address high-frequency, real-time quality evaluation during exploration, we introduce a new concept called guard-points, which guides the robot toward areas with insufficient point cloud density. These guard-points, alongside conventional frontier-based viewpoints, enable our planner to dynamically balance exploration and reconstruction quality. This system not only controls the mobile robot to visit unknown places and areas with insufficient reconstruction quality but also facilitates high-frequency, real-time exploration path planning. This paper concludes with various simulations and real-world experiments to validate the effectiveness of our system.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"112 ","pages":"Article 103409"},"PeriodicalIF":3.1,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-17DOI: 10.1016/j.mechatronics.2025.103417
Xiulu Liu, Zirui Song, Liqiang Xu
To address insufficient clamping force and instability in traditional soft grippers, this study presents a bio-inspired soft gripper with SMA-based variable stiffness. Inspired by human hand musculature and bone structure, the design combines a silicone-based soft finger with a variable-stiffness module. This integration enables adjustable stiffness while retaining softness, significantly enhancing clamping performance. Experimental results show the variable-stiffness gripper achieves a maximum single-finger fingertip force of 1.7 N, representing a 112.5% improvement over the traditional soft gripper. Maximum fingertip and wrap-around clamping weights reach 259.33 g and 524.97 g, corresponding to 126.96% and 97.7% increases, respectively. The gripper demonstrates robust adaptability in household scenarios, effectively handling objects ranging from fragile foods to everyday tools.
{"title":"Bio-inspired soft gripper with SMA-based variable stiffness","authors":"Xiulu Liu, Zirui Song, Liqiang Xu","doi":"10.1016/j.mechatronics.2025.103417","DOIUrl":"10.1016/j.mechatronics.2025.103417","url":null,"abstract":"<div><div>To address insufficient clamping force and instability in traditional soft grippers, this study presents a bio-inspired soft gripper with SMA-based variable stiffness. Inspired by human hand musculature and bone structure, the design combines a silicone-based soft finger with a variable-stiffness module. This integration enables adjustable stiffness while retaining softness, significantly enhancing clamping performance. Experimental results show the variable-stiffness gripper achieves a maximum single-finger fingertip force of 1.7 N, representing a 112.5% improvement over the traditional soft gripper. Maximum fingertip and wrap-around clamping weights reach 259.33 g and 524.97 g, corresponding to 126.96% and 97.7% increases, respectively. The gripper demonstrates robust adaptability in household scenarios, effectively handling objects ranging from fragile foods to everyday tools.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"112 ","pages":"Article 103417"},"PeriodicalIF":3.1,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents the characterization and validation of a multichamber air spring, a pneumatic suspension system comprising a primary chamber linked to multiple auxiliary air reservoirs through electronically controlled valves. Multichamber air springs represent complex electromechanical systems, where valve control and chamber states significantly influence the suspension’s equivalent stiffness. The primary objective of this study is to introduce a novel control-oriented mathematical model for the air spring that more accurately captures the intricate dynamical behaviours than traditional models. By incorporating the dynamics of air mass flow through the valves, the proposed model captures the elastic force during both the opening and closing of the valves, while also accounting for damping phenomena induced by internal friction. Experimental validation is conducted using a suspension test bench, demonstrating that the simulated forces match the measured values across various tests, including realistic driving scenarios characterized by high-frequency stiffness modulation on off-road terrains. This study illustrates how approaching the dynamics from a control-oriented perspective paves the way for enhanced vehicle dynamics control.
{"title":"Control-oriented modelling and experimental validation of a controllable multichamber air spring suspension","authors":"Sabrina Milani, Gabriele Marini, Giulio Panzani, Matteo Corno, Sergio M. Savaresi","doi":"10.1016/j.mechatronics.2025.103406","DOIUrl":"10.1016/j.mechatronics.2025.103406","url":null,"abstract":"<div><div>This paper presents the characterization and validation of a multichamber air spring, a pneumatic suspension system comprising a primary chamber linked to multiple auxiliary air reservoirs through electronically controlled valves. Multichamber air springs represent complex electromechanical systems, where valve control and chamber states significantly influence the suspension’s equivalent stiffness. The primary objective of this study is to introduce a novel control-oriented mathematical model for the air spring that more accurately captures the intricate dynamical behaviours than traditional models. By incorporating the dynamics of air mass flow through the valves, the proposed model captures the elastic force during both the opening and closing of the valves, while also accounting for damping phenomena induced by internal friction. Experimental validation is conducted using a suspension test bench, demonstrating that the simulated forces match the measured values across various tests, including realistic driving scenarios characterized by high-frequency stiffness modulation on off-road terrains. This study illustrates how approaching the dynamics from a control-oriented perspective paves the way for enhanced vehicle dynamics control.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"112 ","pages":"Article 103406"},"PeriodicalIF":3.1,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-09DOI: 10.1016/j.mechatronics.2025.103410
Muhammad Shalihan , Zhiqiang Cao , Billy Pik Lik Lau , Ran Liu , Chau Yuen , U-Xuan Tan
Accurate relative localization of multiple robots is crucial for efficient collaboration and teaming, where a prior map of the environment is often unavailable. In this context, proximal robot detection plays an important role in improving relative localization accuracy by providing essential spatial awareness. While LiDAR is a common choice for detecting nearby robots, it struggles to distinguish them from surrounding obstacles, especially in cluttered environments. To address this challenge, we introduce MR-FLOUR, which stands for Multiple-robot Relative localization based on the Fusion of LiDAR detection outcomes, Odometry, and UWB Ranging. The main innovation of our approach is the use of different sensors for proximal robot detection and the introduction of our LiDAR detection constraint for optimization. First, we propose an efficient method to integrate UWB ranging with LiDAR data for proximal robot detection. We cluster the LiDAR point cloud and apply circle-fitting on the clusters based on the expected radius of the robot to reject clusters that do not conform to the expected shape of the robot. Then match the UWB ranging with cluster distances to determine nearby robot positions. Next, we estimate the identified robot’s orientation from successive detections, with outliers filtered using short-term odometry data. Finally, through Pose Graph Optimization (PGO), we fuse odometry and UWB ranging constraints with our proposed LiDAR detection constraint, which not only accounts for the position and orientation estimations of the nearby robots but also incorporates the relative pose estimation between them. Our method improves the localization accuracy of traditional UWB localization by incorporating LiDAR detection constraints when in Line-Of-Sight (LOS). In Non-Line-Of-Sight (NLOS) conditions or when no nearby robot detections are available, it relies on UWB and odometry for localization. We validated the approach with three robots in three indoor environments, achieving up to 33.3% improvement in translation and 45.5% in rotation over traditional UWB localization.
{"title":"MR-FLOUR: Multi-robot Relative localization based on the Fusion of LiDAR, Odometry, and UWB Ranging","authors":"Muhammad Shalihan , Zhiqiang Cao , Billy Pik Lik Lau , Ran Liu , Chau Yuen , U-Xuan Tan","doi":"10.1016/j.mechatronics.2025.103410","DOIUrl":"10.1016/j.mechatronics.2025.103410","url":null,"abstract":"<div><div>Accurate relative localization of multiple robots is crucial for efficient collaboration and teaming, where a prior map of the environment is often unavailable. In this context, proximal robot detection plays an important role in improving relative localization accuracy by providing essential spatial awareness. While LiDAR is a common choice for detecting nearby robots, it struggles to distinguish them from surrounding obstacles, especially in cluttered environments. To address this challenge, we introduce MR-FLOUR, which stands for <u>M</u>ultiple-robot <u>R</u>elative localization based on the <u>F</u>usion of <u>L</u>iDAR detection outcomes, <u>O</u>dometry, and <u>U</u>WB <u>R</u>anging. The main innovation of our approach is the use of different sensors for proximal robot detection and the introduction of our LiDAR detection constraint for optimization. First, we propose an efficient method to integrate UWB ranging with LiDAR data for proximal robot detection. We cluster the LiDAR point cloud and apply circle-fitting on the clusters based on the expected radius of the robot to reject clusters that do not conform to the expected shape of the robot. Then match the UWB ranging with cluster distances to determine nearby robot positions. Next, we estimate the identified robot’s orientation from successive detections, with outliers filtered using short-term odometry data. Finally, through Pose Graph Optimization (PGO), we fuse odometry and UWB ranging constraints with our proposed LiDAR detection constraint, which not only accounts for the position and orientation estimations of the nearby robots but also incorporates the relative pose estimation between them. Our method improves the localization accuracy of traditional UWB localization by incorporating LiDAR detection constraints when in Line-Of-Sight (LOS). In Non-Line-Of-Sight (NLOS) conditions or when no nearby robot detections are available, it relies on UWB and odometry for localization. We validated the approach with three robots in three indoor environments, achieving up to 33.3% improvement in translation and 45.5% in rotation over traditional UWB localization.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"112 ","pages":"Article 103410"},"PeriodicalIF":3.1,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-03DOI: 10.1016/j.mechatronics.2025.103407
Hugo A. Moreno , Luis A. Moreno , L.M. Valentín-Coronado , Gerardo Flores
The adaptability of legged robots to uneven terrain and their minimal ground impact have driven significant research advancements, establishing them as ideal solutions for complex and delicate environments. Tactile sensing and environmental perception are critical for enhancing robot performance, as they are essential for maintaining dynamic balance and achieving precise control. This paper presents a novel soft contact and force sensor designed for quadrupedal robot legs’ pads (end effectors). The innovative soft sensitive paw, made from flexible conductive membranes, simultaneously measures force and contact point position, enabling environmentally aware decision-making and supporting proprioceptive awareness. Experimental tests demonstrate its soft, spherical design provides excellent adaptability and grip on various terrains. Its sensing surface covers 83.3% of the sphere’s area, with a measurement error of only 0.14%. This capability allows the sensitive paw to detect ground contact as well as lateral and upper leg interactions, offering a robust and versatile tool for navigation and operation in complex environments. To validate its performance, the sensor was tested using custom-built test benches and subsequently mounted on the Lupoh quadruped robot, which was developed in our laboratory for further evaluation.
{"title":"Soft paw sensor for tactile and force sensing in legged robots","authors":"Hugo A. Moreno , Luis A. Moreno , L.M. Valentín-Coronado , Gerardo Flores","doi":"10.1016/j.mechatronics.2025.103407","DOIUrl":"10.1016/j.mechatronics.2025.103407","url":null,"abstract":"<div><div>The adaptability of legged robots to uneven terrain and their minimal ground impact have driven significant research advancements, establishing them as ideal solutions for complex and delicate environments. Tactile sensing and environmental perception are critical for enhancing robot performance, as they are essential for maintaining dynamic balance and achieving precise control. This paper presents a novel soft contact and force sensor designed for quadrupedal robot legs’ pads (end effectors). The innovative soft sensitive paw, made from flexible conductive membranes, simultaneously measures force and contact point position, enabling environmentally aware decision-making and supporting proprioceptive awareness. Experimental tests demonstrate its soft, spherical design provides excellent adaptability and grip on various terrains. Its sensing surface covers 83.3% of the sphere’s area, with a measurement error of only 0.14%. This capability allows the sensitive paw to detect ground contact as well as lateral and upper leg interactions, offering a robust and versatile tool for navigation and operation in complex environments. To validate its performance, the sensor was tested using custom-built test benches and subsequently mounted on the Lupoh quadruped robot, which was developed in our laboratory for further evaluation.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"111 ","pages":"Article 103407"},"PeriodicalIF":3.1,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-16DOI: 10.1016/j.mechatronics.2025.103397
Lie Guo , Jiaqing Zhao , Longxin Guan , Jiahao Wang , Pingshu Ge , Linli Xu
Multi-axle distributed drive vehicles, characterized by over-actuation, internal dynamics, and nonlinear external disturbances, frequently encounter coordination challenges in lateral path tracking, yaw stability intervention, and longitudinal speed control. These issues can significantly degrade overall control performance, particularly under complex driving conditions. To address them, this paper proposes a coordinated control framework integrating path tracking, yaw stability intervention, longitudinal drive control, and optimal torque distribution. First, a robust path tracking controller based on a linear parameter-varying (LPV) dynamic model is designed and a longitudinal speed controller using a linear sliding mode approach are designed. Subsequently, a direct yaw-moment control (DYC) strategy based on nonsingular terminal sliding mode control (NTSMC) with nonlinear dynamic triggering is introduced to mitigate performance degradation induced by excessive interventions. Finally, an optimal torque distribution method based on the Karush–Kuhn–Tucker (KKT) conditions is developed to ensure the feasibility of the solutions. The effectiveness and superiority of the proposed coordination framework are validated through hardware-in-the-loop (HiL) experiments.
{"title":"Coordination control of multi-axle distributed drive vehicle with dynamically-triggered DYC intervention and KKT-based torque optimization distribution","authors":"Lie Guo , Jiaqing Zhao , Longxin Guan , Jiahao Wang , Pingshu Ge , Linli Xu","doi":"10.1016/j.mechatronics.2025.103397","DOIUrl":"10.1016/j.mechatronics.2025.103397","url":null,"abstract":"<div><div>Multi-axle distributed drive vehicles, characterized by over-actuation, internal dynamics, and nonlinear external disturbances, frequently encounter coordination challenges in lateral path tracking, yaw stability intervention, and longitudinal speed control. These issues can significantly degrade overall control performance, particularly under complex driving conditions. To address them, this paper proposes a coordinated control framework integrating path tracking, yaw stability intervention, longitudinal drive control, and optimal torque distribution. First, a robust path tracking controller based on a linear parameter-varying (LPV) dynamic model is designed and a longitudinal speed controller using a linear sliding mode approach are designed. Subsequently, a direct yaw-moment control (DYC) strategy based on nonsingular terminal sliding mode control (NTSMC) with nonlinear dynamic triggering is introduced to mitigate performance degradation induced by excessive interventions. Finally, an optimal torque distribution method based on the Karush–Kuhn–Tucker (KKT) conditions is developed to ensure the feasibility of the solutions. The effectiveness and superiority of the proposed coordination framework are validated through hardware-in-the-loop (HiL) experiments.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"111 ","pages":"Article 103397"},"PeriodicalIF":3.1,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-16DOI: 10.1016/j.mechatronics.2025.103395
Ryan G. Coe, Giorgio Bacelli, Daniel Gaebele, Alicia Keow, Dominic Forbush
As with other oscillatory power conversion systems, the design of wave energy converters can be understood as an impedance matching problem. By representing the wave energy converter as a multi-port network, two separate but related impedance matching conditions can be established. Satisfying these conditions maximizes power transfer to the load. In practice, these impedance matching conditions may be used to influence the design of the system (including the hull, power take-off, controller, mooring, etc.). To this end, this paper considers some example applications of wave energy converter design with the help of the impedance matching framework.
{"title":"Co-design of a wave energy converter through bi-conjugate impedance matching","authors":"Ryan G. Coe, Giorgio Bacelli, Daniel Gaebele, Alicia Keow, Dominic Forbush","doi":"10.1016/j.mechatronics.2025.103395","DOIUrl":"10.1016/j.mechatronics.2025.103395","url":null,"abstract":"<div><div>As with other oscillatory power conversion systems, the design of wave energy converters can be understood as an impedance matching problem. By representing the wave energy converter as a multi-port network, two separate but related impedance matching conditions can be established. Satisfying these conditions maximizes power transfer to the load. In practice, these impedance matching conditions may be used to influence the design of the system (including the hull, power take-off, controller, mooring, etc.). To this end, this paper considers some example applications of wave energy converter design with the help of the impedance matching framework.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"111 ","pages":"Article 103395"},"PeriodicalIF":3.1,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-13DOI: 10.1016/j.mechatronics.2025.103394
Max van Meer , Tim van Meijel , Emile van Halsema , Edwin Verschueren , Gert Witvoet , Tom Oomen
Piezo-stepper actuators enable accurate positioning through the sequential contraction and expansion of piezoelectric elements, generating a walking motion. The aim of this paper is to reduce velocity ripples caused by parasitic effects, due to hysteresis in the piezoelectric material and mechanical misalignments, through suitable feedforward control. The presented approach involves the integration of a rate-dependent hysteresis model with a position-dependent feedforward learning scheme to compensate for these effects. Experimental results show that this approach leads to a significant reduction in the velocity ripples, even when the target velocity is changed. These results enable the use of piezo-stepper actuators in applications requiring high positioning accuracy and stiffness over a long stroke, without requiring expensive position sensors for high-gain feedback.
{"title":"Compensating hysteresis and mechanical misalignment in piezo-stepper actuators","authors":"Max van Meer , Tim van Meijel , Emile van Halsema , Edwin Verschueren , Gert Witvoet , Tom Oomen","doi":"10.1016/j.mechatronics.2025.103394","DOIUrl":"10.1016/j.mechatronics.2025.103394","url":null,"abstract":"<div><div>Piezo-stepper actuators enable accurate positioning through the sequential contraction and expansion of piezoelectric elements, generating a walking motion. The aim of this paper is to reduce velocity ripples caused by parasitic effects, due to hysteresis in the piezoelectric material and mechanical misalignments, through suitable feedforward control. The presented approach involves the integration of a rate-dependent hysteresis model with a position-dependent feedforward learning scheme to compensate for these effects. Experimental results show that this approach leads to a significant reduction in the velocity ripples, even when the target velocity is changed. These results enable the use of piezo-stepper actuators in applications requiring high positioning accuracy and stiffness over a long stroke, without requiring expensive position sensors for high-gain feedback.</div></div>","PeriodicalId":49842,"journal":{"name":"Mechatronics","volume":"111 ","pages":"Article 103394"},"PeriodicalIF":3.1,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-11DOI: 10.1016/j.mechatronics.2025.103396
Jiaoyang Lu , Xianta Jiang , Ting Zou
Precise measurement of the interaction force between the robot and its environment benefits the decision-making processes in various robotic applications. Compared with sensor-based methods, sensorless approaches are commonly preferred due to their versatility and cost-effectiveness. This paper introduces a learning-based method that leverages the state-of-the-art transformer to accurately estimate the interaction force. In contrast to other estimation methods relying on accurate robot dynamic parameters, state information or image features, a notable innovation of our work is the utilization of the limited set of features. The elaborate feature set only includes the joint angle, velocity, and driven torque, with the omission of joint acceleration—a basic robot state typically employed in other research. This configuration expands the feasibility of the presented approach to low-cost robots which are solely equipped with encoders in each joint, and to scenarios where the collection of clear and unobstructed visual features are challenging. Another distinctive feature of our work is that both soft and stiff objects during interaction are considered. Results from the experiment demonstrate that, in comparison to previous image-based methods, our framework achieves an equivalent or even superior level of accuracy across a broader spectrum of environments. Additionally, due to the elimination of joint acceleration from the feature set, the proposed framework sacrifices a small degree of accuracy compared with some non-image-based methods to broaden its applicability.
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