An Adaptive Grasping Force Tracking Strategy for Nonlinear and Time-Varying Object Behaviors

Fuente: arXiv
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Autores principales: Cheng, Ziyang, Tian, Xiangyu, Sui, Ruomin, Li, Tiemin, Jiang, Yao
Formato: Preprint
Publicado: 2024
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author Cheng, Ziyang
Tian, Xiangyu
Sui, Ruomin
Li, Tiemin
Jiang, Yao
author_facet Cheng, Ziyang
Tian, Xiangyu
Sui, Ruomin
Li, Tiemin
Jiang, Yao
contents Accurate grasp force control is one of the key skills for ensuring successful and damage-free robotic grasping of objects. Although existing methods have conducted in-depth research on slip detection and grasping force planning, they often overlook the issue of adaptive tracking of the actual force to the target force when handling objects with different material properties. The optimal parameters of a force tracking controller are significantly influenced by the object's stiffness, and many adaptive force tracking algorithms rely on stiffness estimation. However, real-world objects often exhibit viscous, plastic, or other more complex nonlinear time-varying behaviors, and existing studies provide insufficient support for these materials in terms of stiffness definition and estimation. To address this, this paper introduces the concept of generalized stiffness, extending the definition of stiffness to nonlinear time-varying grasp system models, and proposes an online generalized stiffness estimator based on Long Short-Term Memory (LSTM) networks. Based on generalized stiffness, this paper proposes an adaptive parameter adjustment strategy using a PI controller as an example, enabling dynamic force tracking for objects with varying characteristics. Experimental results demonstrate that the proposed method achieves high precision and short probing time, while showing better adaptability to non-ideal objects compared to existing methods. The method effectively solves the problem of grasp force tracking in unknown, nonlinear, and time-varying grasp systems, demonstrating the generalization capability of our neural network and enhancing the robotic grasping ability in unstructured environments.
format Preprint
id arxiv_https___arxiv_org_abs_2412_02335
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle An Adaptive Grasping Force Tracking Strategy for Nonlinear and Time-Varying Object Behaviors
Cheng, Ziyang
Tian, Xiangyu
Sui, Ruomin
Li, Tiemin
Jiang, Yao
Robotics
Machine Learning
Systems and Control
Accurate grasp force control is one of the key skills for ensuring successful and damage-free robotic grasping of objects. Although existing methods have conducted in-depth research on slip detection and grasping force planning, they often overlook the issue of adaptive tracking of the actual force to the target force when handling objects with different material properties. The optimal parameters of a force tracking controller are significantly influenced by the object's stiffness, and many adaptive force tracking algorithms rely on stiffness estimation. However, real-world objects often exhibit viscous, plastic, or other more complex nonlinear time-varying behaviors, and existing studies provide insufficient support for these materials in terms of stiffness definition and estimation. To address this, this paper introduces the concept of generalized stiffness, extending the definition of stiffness to nonlinear time-varying grasp system models, and proposes an online generalized stiffness estimator based on Long Short-Term Memory (LSTM) networks. Based on generalized stiffness, this paper proposes an adaptive parameter adjustment strategy using a PI controller as an example, enabling dynamic force tracking for objects with varying characteristics. Experimental results demonstrate that the proposed method achieves high precision and short probing time, while showing better adaptability to non-ideal objects compared to existing methods. The method effectively solves the problem of grasp force tracking in unknown, nonlinear, and time-varying grasp systems, demonstrating the generalization capability of our neural network and enhancing the robotic grasping ability in unstructured environments.
title An Adaptive Grasping Force Tracking Strategy for Nonlinear and Time-Varying Object Behaviors
topic Robotics
Machine Learning
Systems and Control
url https://arxiv.org/abs/2412.02335