manipulator
Fast Functionally Redundant Inverse Kinematics for Robotic Toolpath Optimisation in Manufacturing Tasks
Razjigaev, Andrew, Lohr, Hans, Vargas-Uscategui, Alejandro, King, Peter, Bandyopadhyay, Tirthankar
Abstract--Industrial automation with six-axis robotic arms is critical for many manufacturing tasks, including welding and additive manufacturing applications; however, many of these operations are functionally redundant due to the symmetrical tool axis, which effectively makes the operation a five-axis task. Exploiting this redundancy is crucial for achieving the desired workspace and dexterity required for the feasibility and optimisation of toolpath planning. Inverse kinematics algorithms can solve this in a fast, reactive framework, but these techniques are underutilised over the more computationally expensive offline planning methods. We propose a novel algorithm to solve functionally redundant inverse kinematics for robotic manipulation utilising a task space decomposition approach, the damped least-squares method and Halley's method to achieve fast and robust solutions with reduced joint motion. We evaluate our methodology in the case of toolpath optimisation in a cold spray coating application on a non-planar surface. The functionally redundant inverse kinematics algorithm can quickly solve motion plans that minimise joint motion, expanding the feasible operating space of the complex toolpath.
- Europe > Switzerland > Zürich > Zürich (0.14)
- Oceania > Australia (0.04)
- North America > United States (0.04)
- Europe > Germany (0.04)
Development of a Compliant Gripper for Safe Robot-Assisted Trouser Dressing-Undressing
Unde, Jayant, Inden, Takumi, Wakayama, Yuki, Colan, Jacinto, Zhu, Yaonan, Aoyama, Tadayoshi, Hasegawa, Yasuhisa
In recent years, many countries, including Japan, have rapidly aging populations, making the preservation of seniors' quality of life a significant concern. For elderly people with impaired physical abilities, support for toileting is one of the most important issues. This paper details the design, development, experimental assessment, and potential application of the gripper system, with a focus on the unique requirements and obstacles involved in aiding elderly or hemiplegic individuals in dressing and undressing trousers. The gripper we propose seeks to find the right balance between compliance and grasping forces, ensuring precise manipulation while maintaining a safe and compliant interaction with the users. The gripper's integration into a custom--built robotic manipulator system provides a comprehensive solution for assisting hemiplegic individuals in their dressing and undressing tasks. Experimental evaluations and comparisons with existing studies demonstrate the gripper's ability to successfully assist in both dressing and dressing of trousers in confined spaces with a high success rate. This research contributes to the advancement of assistive robotics, empowering elderly, and physically impaired individuals to maintain their independence and improve their quality of life.
- Asia > Japan > Honshū > Kansai > Wakayama Prefecture > Wakayama (0.41)
- Asia > Japan > Honshū > Chūbu > Aichi Prefecture > Nagoya (0.05)
- South America > Uruguay > Montevideo > Montevideo (0.04)
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Data-Driven Dynamic Parameter Learning of manipulator robots
Elseiagy, Mohammed, Alemayoh, Tsige Tadesse, Bezerra, Ranulfo, Kojima, Shotaro, Ohno, Kazunori
Bridging the sim-to-real gap remains a fundamental challenge in robotics, as accurate dynamic parameter estimation is essential for reliable model-based control, realistic simulation, and safe deployment of manipulators. Traditional analytical approaches often fall short when faced with complex robot structures and interactions. Data-driven methods offer a promising alternative, yet conventional neural networks such as recurrent models struggle to capture long-range dependencies critical for accurate estimation. In this study, we propose a Transformer-based approach for dynamic parameter estimation, supported by an automated pipeline that generates diverse robot models and enriched trajectory data using Jacobian-derived features. The dataset consists of 8,192 robots with varied inertial and frictional properties. Leveraging attention mechanisms, our model effectively captures both temporal and spatial dependencies. Experimental results highlight the influence of sequence length, sampling rate, and architecture, with the best configuration (sequence length 64, 64 Hz, four layers, 32 heads) achieving a validation R2 of 0.8633. Mass and inertia are estimated with near-perfect accuracy, Coulomb friction with moderate-to-high accuracy, while viscous friction and distal link center-of-mass remain more challenging. These results demonstrate that combining Transformers with automated dataset generation and kinematic enrichment enables scalable, accurate dynamic parameter estimation, contributing to improved sim-to-real transfer in robotic systems
- Asia > Japan > Honshū > Tōhoku > Miyagi Prefecture > Sendai (0.04)
- Africa > Middle East > Egypt > Alexandria Governorate > Alexandria (0.04)
UMI-on-Air: Embodiment-Aware Guidance for Embodiment-Agnostic Visuomotor Policies
Gupta, Harsh, Guo, Xiaofeng, Ha, Huy, Pan, Chuer, Cao, Muqing, Lee, Dongjae, Scherer, Sebastian, Song, Shuran, Shi, Guanya
We introduce UMI-on-Air, a framework for embodiment-aware deployment of embodiment-agnostic manipulation policies. Our approach leverages diverse, unconstrained human demonstrations collected with a handheld gripper (UMI) to train generalizable visuomotor policies. A central challenge in transferring these policies to constrained robotic embodiments-such as aerial manipulators-is the mismatch in control and robot dynamics, which often leads to out-of-distribution behaviors and poor execution. To address this, we propose Embodiment-Aware Diffusion Policy (EADP), which couples a high-level UMI policy with a low-level embodiment-specific controller at inference time. By integrating gradient feedback from the controller's tracking cost into the diffusion sampling process, our method steers trajectory generation towards dynamically feasible modes tailored to the deployment embodiment. This enables plug-and-play, embodiment-aware trajectory adaptation at test time. We validate our approach on multiple long-horizon and high-precision aerial manipulation tasks, showing improved success rates, efficiency, and robustness under disturbances compared to unguided diffusion baselines. Finally, we demonstrate deployment in previously unseen environments, using UMI demonstrations collected in the wild, highlighting a practical pathway for scaling generalizable manipulation skills across diverse-and even highly constrained-embodiments. All code, data, and checkpoints will be publicly released after acceptance. Result videos can be found at umi-on-air.github.io.
Disturbance Compensation for Safe Kinematic Control of Robotic Systems with Closed Architecture
Zhang, Fan, Chen, Jinfeng, Ahanda, Joseph J. B. Mvogo, Richter, Hanz, Lv, Ge, Hu, Bin, Lin, Qin
XX 1 Disturbance Compensation for Safe Kinematic Control of Robotic Systems with Closed Architecture Fan Zhang 1,2, Jinfeng Chen 1, Joseph J. B. Mvogo Ahanda 3, Hanz Richter 4, Ge Lv 5, Bin Hu 1,2, Qin Lin 1,2 Abstract--In commercial robotic systems, it is common to encounter a closed inner-loop (low-level) torque controller that is not user-modifiable. However, the outer-loop controller, which sends kinematic commands such as position or velocity for the inner-loop controller to track, is typically exposed to users. In this work, we focus on the development of an easily integrated add-on at the outer-loop layer by combining disturbance rejection control and robust control barrier function for high-performance tracking and safe control of the whole dynamic system of an industrial manipulator . This is particularly beneficial when 1) the inner-loop controller is imperfect, unmodifiable, and uncertain; and 2) the dynamic model exhibits significant uncertainty. Stability analysis, formal safety guarantee proof, simulations, and hardware experiments with a PUMA robotic manipulator are presented. Our solution demonstrates superior performance in terms of simplicity of implementation, robustness, tracking precision, and safety compared to the state of the art. I. INTRODUCTION Robotic systems often employ hierarchical software design, stacking perception, decision-making, planning, and low-level control. Such modularity is particularly beneficial for troubleshooting and improving the reliability of robotic systems. For example, in the control block, a combination of a kinematic controller (outer-loop controller) and a dynamic controller (inner-loop controller) is commonly seen in various robots. However, because tuning the inner-loop controller requires expert knowledge, this component is typically not exposed to users due to product safety considerations, a practice referred to as closed architecture in the literature [1]-[4]. In other words, users are only allowed to design the kinematic controller, sending position or velocity for the inner-loop controller to track. Additionally, mechanical parts 1 The authors are with the Department of Engineering Technology, University of Houston, USA. Corresponding author: Qin Lin, qlin21@central.uh.edu 2 Fan Zhang is also with the Department of Electrical and Computer Engineering, University of Houston, USA 3 Joseph Jean Baptiste Mvogo Ahanda is with the Department of Biomedical Engineering, The University of Ebolowa, Cameroon 4 Hanz Richter is with the Department of Mechanical Engineering, Cleveland State University, USA 5 Ge Lv is with the Department of Mechanical Engineering, Clemson University, USA. This material is based upon work supported by the National Science Foundation under Grant Nos.
- North America > United States > Texas > Harris County > Houston (0.24)
- Africa > Cameroon > South Region > Ebolowa (0.24)
Model-Less Feedback Control of Space-based Continuum Manipulators using Backbone Tension Optimization
Rajneesh, Shrreya, Pavle, Nikita, Sahoo, Rakesh Kumar, Sinha, Manoranjan
Continuum manipulators offer intrinsic dexterity and safe geometric compliance for navigation within confined and obstacle-rich environments. However, their infinite-dimensional backbone deformation, unmodeled internal friction, and configuration-dependent stiffness fundamentally limit the reliability of model-based kinematic formulations, resulting in inaccurate Jacobian predictions, artificial singularities, and unstable actuation behavior. Motivated by these limitations, this work presents a complete model-less control framework that bypasses kinematic modeling by using an empirically initialized Jacobian refined online through differential convex updates. Tip motion is generated via a real-time quadratic program that computes actuator increments while enforcing tendon slack avoidance and geometric limits. A backbone-tension optimization term is introduced in this paper to regulate axial loading and suppress co-activation compression. The framework is validated across circular, pentagonal, and square trajectories, demonstrating smooth convergence, stable tension evolution, and sub-millimeter steady-state accuracy without any model calibration or parameter identification. These results establish the proposed controller as a scalable alternative to model-dependent continuum manipulation in a constrained environment.
- Asia > India > West Bengal > Kharagpur (0.05)
- North America > United States (0.04)
FALCON: Actively Decoupled Visuomotor Policies for Loco-Manipulation with Foundation-Model-Based Coordination
He, Chengyang, Sun, Ge, Bai, Yue, Lu, Junkai, Zhao, Jiadong, Sartoretti, Guillaume
F ALCON actively decouples locomotion and manipulation through two modular diffusion policies, coordinated by a vision-language foundation model. The VLM encodes global scene context, proprioceptive states, and goal instructions into a shared latent embedding that conditions both subsystems. Abstract--We present FoundAtion-model-guided decoupled LoCO-maNipulation visuomotor policies (F ALCON), a framework for loco-manipulation that combines modular diffusion policies with a vision-language foundation model as the coordinator . Our approach explicitly decouples locomotion and manipulation into two specialized visuomotor policies, allowing each subsystem to rely on its own observations. This mitigates the performance degradation that arise when a single policy is forced to fuse heterogeneous, potentially mismatched observations from locomotion and manipulation. Our key innovation lies in restoring coordination between these two independent policies through a vision-language foundation model, which encodes global observations and language instructions into a shared latent embedding conditioning both diffusion policies. On top of this backbone, we introduce a phase-progress head that uses textual descriptions of task stages to infer discrete phase and continuous progress estimates without manual phase labels. T o further structure the latent space, we incorporate a coordination-aware contrastive loss that explicitly encodes cross-subsystem compatibility between arm and base actions. Results show that it surpasses centralized and decentralized baselines while exhibiting improved robustness and generalization to out-of-distribution scenarios. ECENT progress in robot learning and foundation models has rekindled the longstanding vision of general-purpose robots that can move through unstructured environments and manipulate diverse objects with minimal task-specific engineering. Large Behavior Models (LBMs) extend the diffusion policy paradigm to multi-task dexterous manipulation [1], training a single policy across broad datasets of real and simulated trajectories. Robotics' Memo platform [8], demonstrate impressive whole-body behaviors that combine locomotion, manipulation, and language grounding in increasingly realistic environments. These developments suggest a future where robot generalist models consume raw sensor streams and language instructions and directly output actions to interact with the physical world. However, loco-manipulation, jointly controlling a mobile base and one or more arms, remains especially challenging on legged platforms [9]-[11], where the same body must simultaneously maintain stability and accomplish precise manipulation under different sensor streams and poses. In this work, we focus on a specific yet representative setting in which an arm-mounted quadruped robot performs long-horizon loco-manipulation tasks using only RGB observations, proprioceptive states, and sparse language instructions.
- Information Technology > Artificial Intelligence > Robots > Locomotion (0.66)
- Information Technology > Artificial Intelligence > Robots > Manipulation (0.48)
- Information Technology > Artificial Intelligence > Natural Language > Large Language Model (0.46)
- Information Technology > Artificial Intelligence > Robots > Robot Planning & Action (0.46)
Multimodal Control of Manipulators: Coupling Kinematics and Vision for Self-Driving Laboratory Operations
Sulaiman, Shifa, H, Amarnath, Bogh, Simon, Marturi, Naresh
Motion planning schemes are used for planning motions of a manipulator from an initial pose to a final pose during a task execution. A motion planning scheme generally comprises of a trajectory planning method and an inverse kinematic solver to determine trajectories and joints solutions respectively. In this paper, 3 motion planning schemes developed based on Jacobian methods are implemented to traverse a redundant manipulator with a coupled finger gripper through given trajectories. RRT* algorithm is used for planning trajectories and screw theory based forward kinematic equations are solved for determining joint solutions of the manipulator and gripper. Inverse solutions are computed separately using 3 Jacobian based methods such as Jacobian Transpose (JT), Pseudo Inverse (PI), and Damped Least Square (DLS) methods. Space Jacobian and manipulability measurements of the manipulator and gripper are obtained using screw theory formulations. Smoothness and RMSE error of generated trajectories and velocity continuity, acceleration profile, jerk, and snap values of joint motions are analysed for determining an efficient motion planning method for a given task. Advantages and disadvantages of the proposed motion planning schemes mentioned above are analysed using simulation studies to determine a suitable inverse solution technique for the tasks.
- Europe > United Kingdom > England > West Midlands > Birmingham (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- Europe > Denmark > North Jutland > Aalborg (0.04)
- Asia > India (0.04)
Reinforcement Learning for Robotic Safe Control with Force Sensing
Lin, Nan, Zhang, Linrui, Chen, Yuxuan, Chen, Zhenrui, Zhu, Yujun, Chen, Ruoxi, Wu, Peichen, Chen, Xiaoping
-- For the task with complicated manipulation in unstructured environments, traditional hand-coded methods are ineffective, while reinforcement learning can provide more general and useful policy. Although the reinforcement learning is able to obtain impressive results, its stability and reliability is hard to guarantee, which would cause the potential safety threats. Besides, the transfer from simulation to real-world also will lead in unpredictable situations. T o enhance the safety and reliability of robots, we introduce the force and haptic perception into reinforcement learning. We demonstrate that the force-based reinforcement learning method can be more adaptive to environment, especially in sim-to-real transfer . Experimental results show in object pushing task, our strategy is safer and more efficient in both simulation and real world, thus it holds prospects for a wide variety of robotic applications.
Think Fast: Real-Time Kinodynamic Belief-Space Planning for Projectile Interception
Olin, Gabriel, Chen, Lu, Gandotra, Nayesha, Likhachev, Maxim, Choset, Howie
Intercepting fast moving objects, by its very nature, is challenging because of its tight time constraints. This problem becomes further complicated in the presence of sensor noise because noisy sensors provide, at best, incomplete information, which results in a distribution over target states to be intercepted. Since time is of the essence, to hit the target, the planner must begin directing the interceptor, in this case a robot arm, while still receiving information. We introduce an tree-like structure, which is grown using kinodynamic motion primitives in state-time space. This tree-like structure encodes reachability to multiple goals from a single origin, while enabling real-time value updates as the target belief evolves and seamless transitions between goals. We evaluate our framework on an interception task on a 6 DOF industrial arm (ABB IRB-1600) with an onboard stereo camera (ZED 2i). A robust Innovation-based Adaptive Estimation Adaptive Kalman Filter (RIAE-AKF) is used to track the target and perform belief updates.
- North America > United States (0.04)
- Europe > Portugal > Madeira > Funchal (0.04)
- Asia > Taiwan > Taiwan Province > Taipei (0.04)
- Asia > China > Hong Kong (0.04)