Coordinated Control of Flexible Cables With Human-Like Dual Manipulators

2021 ◽  
Vol 143 (8) ◽  
Author(s):  
Naijing Lv ◽  
Jianhua Liu ◽  
Yunyi Jia

Abstract Due to the flexibility and high degrees-of-freedom of flexible cables, their dynamic modeling and precise control are challenging. In this paper, the dynamic modeling and control of flexible cables with human-like dual manipulators are studied to deploy them on a plane and form the desired shapes automatically. First, we establish a dynamic model of flexible cables based on a discrete elastic rod model. This model can simulate their stretching, bending, and twisting deformations. Then, we consider the collisions, contacts, and frictions between the flexible cables and the plane, add kinematic constraints to the model, and finally obtain an implementable dynamic solution of the model. Next, we propose dynamic control schemes including parallel dual-arm control and coordinated dual-arm control to deploy the flexible cables on a plane and form the desired shapes for dual-arm controls. Finally, experimental and simulation studies are carried out to illustrate the effectiveness of the dynamic model and the validity of the control schemes. The results show that the model can successfully demonstrate the deformations of flexible cables, and the proposed control schemes can successfully manipulate flexible cables in different tasks.

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 155093-155102
Author(s):  
Xin Jing ◽  
Haibo Gao ◽  
Zhengsheng Chen ◽  
Yaobing Wang

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3608 ◽  
Author(s):  
Qianqian Wu ◽  
Ning Cui ◽  
Sifang Zhao ◽  
Hongbo Zhang ◽  
Bilong Liu

The environment in space provides favorable conditions for space missions. However, low frequency vibration poses a great challenge to high sensitivity equipment, resulting in performance degradation of sensitive systems. Due to the ever-increasing requirements to protect sensitive payloads, there is a pressing need for micro-vibration suppression. This paper deals with the modeling and control of a maglev vibration isolation system. A high-precision nonlinear dynamic model with six degrees of freedom was derived, which contains the mathematical model of Lorentz actuators and umbilical cables. Regarding the system performance, a double closed-loop control strategy was proposed, and a sliding mode control algorithm was adopted to improve the vibration isolation performance. A simulation program of the system was developed in a MATLAB environment. A vibration isolation performance in the frequency range of 0.01–100 Hz and a tracking performance below 0.01 Hz were obtained. In order to verify the nonlinear dynamic model and the isolation performance, a principle prototype of the maglev isolation system equipped with accelerometers and position sensors was developed for the experiments. By comparing the simulation results and the experiment results, the nonlinear dynamic model of the maglev vibration isolation system was verified and the control strategy of the system was proved to be highly effective.


2021 ◽  
pp. 1-23
Author(s):  
Stefan Atay ◽  
Matthew Bryant ◽  
Gregory D. Buckner

Abstract This paper presents the dynamic modeling and control of a bi-modal, multirotor vehicle that is capable of omnidirectional terrestrial rolling and multirotor flight. It focuses on the theoretical development of a terrestrial dynamic model and control systems, with experimental validation. The vehicle under consideration may roll along the ground to conserve power and extend endurance but may also fly to provide high mobility and maneuverability when necessary. The vehicle employs a three-axis gimbal system that decouples the rotor orientation from the vehicle's terrestrial rolling motion. A dynamic model of the vehicle's terrestrial motion is derived from first principles. The dynamic model becomes the basis for a nonlinear trajectory tracking control system suited to the architecture of the vehicle. The vehicle is over-actuated while rolling, and the additional degrees of actuation can be used to accomplish auxiliary objectives, such as power optimization and gimbal lock avoidance. Experiments with a hardware vehicle demonstrate the efficacy of the trajectory tracking control system.


Author(s):  
Anthony Garcia ◽  
William Singhose ◽  
Aldo Ferri

When cranes lift payloads off the ground, the payload may slide sideways or swing unexpectedly. This motion occurs when the payload is not directly beneath the overhead suspension point of the hoist cable. Given that cable suspension points can be hundreds of feet above the payload, it is difficult for crane operators to know if the hoist cable is vertical before lifting the payload off the ground. If an off-center lift creates substantial horizontal motion, then it can create significant hazards for the operators, the payload, and the surrounding environment. This paper develops a three-dimensional dynamic model that predicts motions of off-centered lifts.


Author(s):  
Scott G. Olsen ◽  
Gary M. Bone

The low-level modeling and control of mobile robots that interact forcibly with their environment, such as robotic excavation machinery, is a challenging problem that has not been adequately addressed in prior research. This paper investigates the low-level modeling of robotic bulldozing. The proposed model characterizes the three primary degrees-of-freedom (DOF) of the bulldozer, the blade position, the material accumulation on the blade, and the material distribution in the environment. It includes discrete operation modes contained within a hybrid dynamic model framework. The dynamics of the individual modes are represented by a set of linear and nonlinear differential equations. An instrumented scaled-down bulldozer and environment are developed to emulate the full scale operation. Model parameter estimation and validation are completed using experimental data from this system. The model is refined based on a global sensitivity analysis. The refined model is suitable for simulation and design of robotic bulldozing control strategies.


Author(s):  
Houman Dallali ◽  
Evandro Ficanha ◽  
Mohammad Rastgaar Aagaah

The first step to study and develop a two Degrees of Freedom (DOF) prosthesis is to derive a dynamic model for simulation and control design. In this paper, the ankle-foot prosthesis has controllable Dorsi-Plantarflexion (DP) and Inversion-Eversion (IE) DOF. We derive a compliant dynamic model for a recently developed ankle-foot prosthesis followed by identification of the actuators, transmission, and prosthetic foot parameters. The resulting model is then verified experimentally and in simulation. Dynamic decoupling of the actuators to the ankle’s DP and IE DOF is also investigated using Bode plots. The code used for simulating the prosthesis is provided on GitHub for the community.


2021 ◽  
Vol 11 (22) ◽  
pp. 10988
Author(s):  
Jun Cheng ◽  
Shusheng Bi ◽  
Chang Yuan ◽  
Lin Chen ◽  
Yueri Cai ◽  
...  

At present, the absolute positioning accuracy and control accuracy of industrial serial robots need to be improved to meet the accuracy requirements of precision manufacturing and precise control. An accurate dynamic model is an important theoretical basis for solving this problem, and precise dynamic parameters are the prerequisite for precise control. The research of dynamics and parameter identification can greatly promote the application of robots in the field of precision manufacturing and automation. In this paper, we study the dynamical modeling and dynamic parameter identification of an industrial robot system with six rotational DOF (6R robot system) and propose a new method for identifying dynamic parameters. Our aim is to provide an accurate mathematical description of the dynamics of the 6R robot and to accurately identify its dynamic parameters. First, we establish an unconstrained dynamic model for the 6R robot system and rewrite it to obtain the dynamic parameter identification model. Second, we establish the constraint equations of the 6R robot system. Finally, we establish the dynamic model of the constrained 6R robot system. Through the ADAMS simulation experiment, we verify the correctness and accuracy of the dynamic model. The experiments prove that the result of parameter identification has extremely high accuracy and the dynamic model can accurately describe the 6R robot system mathematically. The dynamic modeling method proposed in this paper can be used as the theoretical basis for the study of 6R robot system dynamics and the study of dynamics-based control theory.


Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 112
Author(s):  
Yiqing Li ◽  
Yan Cao ◽  
Feng Jia

Dynamic modeling and control of the soft pneumatic actuators are challenging research. In this paper, a neural network based dynamic control method used for a soft pneumatic actuator with symmetrical chambers is proposed. The neural network is introduced to create the dynamic model for predicting the state of the actuator. In this dynamic model, the effect of the uninflated rubber block on bending deformation is considered. Both pressures of the actuator are used for predicting the state of the actuator during the bending motion. The controller is designed based on this dynamic model for trajectory tracking control. Three types of trajectory tracking control experiments are performed to validate the proposed method. The results show that the proposed control method can control the motion of the actuator and track the trajectory effectively.


Author(s):  
Naoufel Azouz ◽  
Mahmoud Khamlia ◽  
Fida Benabdallah ◽  
Fatma Guesmi

This paper presents the design and the dynamic modeling of a Smart Crane called CHAYASC, designed to equip wide-body airship, which has to carry out loading and unloading operations from a certain altitude. The main function of this crane is to lift, stabilize, maneuver and position large loads by having precise control of the position and orientation of these loads according to the six degrees of freedom. The CHAYASC is based in particular on a Cable Driven Parallel Manipulator and will have a dual mission: 1) deposit and arrange the containers in the hold of the airship, 2) lift and stabilize the containers suspended during a sudden movement of the airship under the effect of a gust of wind.


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