Experiment on a dual-arm underwater robot using resolved acceleration control method

The space station manipulator does lots of tasks with contact force/torque on orbit. To ensure the safety of the space station and the manipulator, the contact force/torque of manipulator must be controlled. Based on analyzing typical tasks’ working flows and force control requirements, such as ORU (orbit replacement unit) changeout and dual arm collaborative payload transport, an impedance control method based on wrist 6 axis force/torque feedback is designed. For engineering implementation of the impedance control algorithm, the discretization method and impedance control parameters selection principle are also studied. To verify the compliance control algorithm, a ground experiment platform adopting industrial manipulators is developed. In order to eliminate the influence of gravity, a real-time gravity compensation algorithm is proposed. Then, the correctness of real-time gravity compensation and force compliance control algorithm is verified on the experiment platform. Finally, the ORU replacement and dual arm collaborative payload transport experiments are done. Experimental results show that the force compliance control method proposed in this paper can control the contact force and torque at the end of the manipulator when executing typical tasks.

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A Multi-Priority Control of Asymmetric Coordination for Redundant Dual-Arm Robot

International Journal of Humanoid Robotics ◽

10.1142/s0219843619500087 ◽

2019 ◽

Vol 16 (02) ◽

pp. 1950008

Author(s):

Fuhai Zhang ◽

Jiadi Qu ◽

He Liu ◽

Yili Fu

Keyword(s):

Secondary Task ◽

Control Method ◽

Null Space ◽

Main Task ◽

External Impact ◽

Dual Arm Robot ◽

End Effectors ◽

Dual Arm ◽

Arm Coordination ◽

Asymmetric Coordination

The paper develops a multi-priority control method of asymmetric coordination for a redundant dual-arm robot. A novel dual-arm coordination impedance is introduced to the multi-priority control, and then the performance of the object tracking and the redundant joints is improved by the regulation of the relative Cartesian errors between two arms. The control of asymmetric coordination is divided into the main task and the secondary task. The control of the main task can regulate the two end-effectors’ errors and the relative errors by building the model of spatial parallel spring and damping (SPSDM), which establishes the dual-arm coordination impedance relation in Cartesian space. The control of the secondary task optimizes the performance of the redundant joint impedance and joint limit avoidance in null space. Finally, a typical asymmetric coordination experiment of peg-in-hole is carried out to verify the validity and feasibility of the proposed method. The results indicate that the proposed dual-arm coordination impedance can regulate the relative tracking errors between two objects directly, and in the context of the external impact force applied to the two end-effectors, the peg-in-hole dual-arm task can be achieved successfully.

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Impact motion control of a flexible dual-arm space robot for capturing a spinning object

International Journal of Advanced Robotic Systems ◽

10.1177/1729881419857534 ◽

2019 ◽

Vol 16 (3) ◽

pp. 172988141985753

Author(s):

Xiali Li ◽

Licheng Wu

Keyword(s):

Motion Control ◽

Control Method ◽

Initial Conditions ◽

Autonomous Vehicle ◽

Stable State ◽

Momentum Conservation ◽

Space Robot ◽

Dynamics Response ◽

The Impact ◽

Dual Arm

As an autonomous vehicle that moves on the space orbit, a space robot needs to be carefully treated on the motion planning and control method. In this article, the optimal impact and postimpact motion control of a flexible dual-arm space robot capturing a spinning object are considered. Firstly, the dynamic model of the robot systems is built by using Lagrangian formulation. The flexible links are modeled as Euler–Bernoulli beams of two bending modes. Through simulating the system’s postimpact dynamics response, the initial conditions are obtained from the impact model. Next, the initial velocities of base and joint are adjusted to minimize the velocity of the base after the capture according to generalized momentum conservation. After the capture, a proportional–derivative controller is designed to keep the robot system’s stabilization. The simulation results show that joint angles of base and manipulators reach stable state quickly, and motions of the space robots also induce vibrating motions of the flexible manipulators.

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Supervisory Control Method for Manipulator Mounted on Underwater Robot

Mekhatronika Avtomatizatsiya Upravlenie ◽

10.17587/mau.19.95-99 ◽

2018 ◽

Vol 19 (2) ◽

pp. 95-99

Author(s):

V. F. Filaretov ◽

◽

A. Yu. Konoplin ◽

N. Yu. Konoplin ◽

◽

...

Keyword(s):

Supervisory Control ◽

Control Method ◽

Underwater Robot

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Depth Control of Underwater Robot with Metal Bellows Mechanism for Buoyancy Control Device Utilizing Phase Transition

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2013.p0795 ◽

2013 ◽

Vol 25 (5) ◽

pp. 795-803

Author(s):

Koji Shibuya ◽

◽

Yukihiro Kishimoto ◽

Sho Yoshii

Keyword(s):

Phase Transition ◽

Control Method ◽

Control Device ◽

Underwater Robot ◽

Maximum Output ◽

Depth Control ◽

Metal Bellows ◽

Control Devices ◽

Target Depth ◽

Buoyancy Control

The ultimate goal of this study is to develop a buoyancy control device that utilizes volume change due to phase transition of material between solid and liquid states. This paper describes the depth control method for an underwater robot fitted with the metal bellows buoyancy control devices that we have developed in this study. Four metal bellows buoyancy control devices are installed on an underwater robot. We first measured underwater robot buoyancy change and found that it agreed roughly with theoretical values. We then checked whether the robot could change buoyancy successively so that the robot rises or sinks as commanded. We then conducted a series of experiments on robot depth control in which if the robot depth is more than a certain distance different from the target depth, control devices are either heated or cooled at maximum output. If such a difference is within the threshold, proportional control is applied to develop output in proportion to the distance to the target depth. Experimental results showed that the underwater robot followed varied target depth with a steady-state deviation of a few cmor so, except in some cases of failure.

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Compliant Control for the Redundant Dual-Arm Live-Working Robot

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.459.177 ◽

2013 ◽

Vol 459 ◽

pp. 177-182

Author(s):

Huan Bing Gao ◽

Shou Yin Lu ◽

Guo Hui Tian

Keyword(s):

Dynamic Model ◽

Force Control ◽

Stiffness Matrix ◽

Control Method ◽

Total System ◽

Kinematic Structure ◽

Compliant Control ◽

Dual Arm

Two arms are attached on the live-working robot for cooperating jobs and some task requiring larger stiffness such as pushing and butting when replacing cross arm or insulator. The different kinematic structure of this two arms brings many difficulties to get the dynamic model of the total system. This paper proposes a force control method to solve this problem. Two arms are considered as one arm firstly, then the general stiffness matrix is obtained. And based on the compliant relationship between the dual arms and the environment, the force control method for the exact force control is presented. The scheme is experimentally tested on the live-working robot, and the effectiveness and rapidity is validated .

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