scholarly journals Design and Implementation of Admittance Control for a Dual-Arm Robot under Space Limitation

2019 ◽  
Vol 256 ◽  
pp. 02010
Author(s):  
Jinxing Yang ◽  
Yinhui Xie ◽  
Mingqi Feng ◽  
Jun Li

Aimed at the situation lack of suitable industrial robots with speed requirement and space limitation, a novel simple structured and high speed dual-arm robot is designed. The robot control system has been achieved by using high speed controller, real-time bus EtherCAT and integrating the sensor system via Ethernet interface. Kinematic and dynamic analysis are the basis of its kinematic control and trajectory planning. This paper presents a force-free control method for direct teaching of the robot and adopts a Cartesian admittance control algorithm to realize human-machine interaction. The admittance control is conducted by utilizing six-dimensional force/torque sensor fixed to the end-effector of manipulator. To evaluate the performance of the proposed controller and control algorithm, a point-to-point teaching task is conducted.

2016 ◽  
Vol 13 (6) ◽  
pp. 172988141666678
Author(s):  
Hongxing Wang ◽  
Ruifeng Li ◽  
Yunfeng Gao ◽  
Chuqing Cao ◽  
Lianzheng Ge

A whole resolved motion rate control algorithm designed for mobile dual-arm redundant robots is presented in this article. Based on this algorithm, the end-effector movements of the dual arms of the mobile dual-arm redundant robot can be decomposed into the movements of the two driving wheels of the differential driving platform and the movements of the dual-arm each joint of this robot harmoniously. The influence of the redundancies of the single- and dual-arm robots on the operation based on the fixed- and differential-driving platforms, which are then based on the whole resolved motion rate control algorithm, is studied after building their motion models. Some comparisons are made to show the advantages of this algorithm on the entire modeling of the complicated robotic system and the influences of the redundancy. First, the comparison of the simulation results between the fixed single-arm robot and the mobile single-arm robot is presented. Second, a comparison of the simulation results between the mobile single-arm robot and the mobile dual-arm robots is shown. Compared with the mobile single-arm robot and the fixed dual-arm robot based on this algorithm, the mobile dual-arm robot has more redundancy and can simultaneously track and operate different objects. Moreover, the mobile dual-arm redundant robot has better smoothness, more flexibility, larger operational space, and more harmonious cooperation between the two arms and the differential driving platform during the entire mobile operational process.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Bingshan Hu ◽  
Huanlong Chen ◽  
Liangliang Han ◽  
Hongliu Yu

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.


2019 ◽  
Vol 16 (02) ◽  
pp. 1950008
Author(s):  
Fuhai Zhang ◽  
Jiadi Qu ◽  
He Liu ◽  
Yili Fu

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.


2010 ◽  
Vol 426-427 ◽  
pp. 572-576
Author(s):  
Can Zhao ◽  
Y.Y. Guo ◽  
Guang Bin Bu

There are two key problems in the manufacture process of impeller with HSM(High Speed Machining). One is the collision between tool and blade, the other is gnawed-cutting arisen by non-uniform change of the cutter axis. The control algorithm of collision-free cutter-axis was described and applied in this paper. The cutter-axis vector was optimized by quaternary linear interpolation method to make normal vector of blade changing continuous, so. These methods were synthetically used in the manufacture experiment. And the qualified impeller was produced. It indicated that the tool vector control method was feasible.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Hubert Gattringer ◽  
Roland Riepl ◽  
Matthias Neubauer

Today’s standard robotic systems often do not meet the industry’s demands for accurate high-speed robotic applications. Any machine, be it an existing or a new one, should be pushed to its limits to provide “optimal” efficiency. However, due to the high complexity of modern applications, a one-step overall optimization is not possible. Therefore, this contribution introduces a step-by-step sequence of multiple nonlinear optimizations. Included are optimal configurations for geometric calibration, best-exciting trajectories for parameter identification, model-based control, and time/energy optimal trajectory planning for continuous path and point-to-point trajectories. Each of these optimizations contributes to the improvement of the overall system. Existing optimization techniques are adapted and extended for use with a standard industrial robot scenario and combined with a comprehensive toolkit with discussions on the interplay between the separate components. Most importantly, all procedures are evaluated in practical experiments on a standard robot with industrial control hardware and the recorded measurements are presented, a step often missing in publications in this area.


2019 ◽  
Vol 16 (4) ◽  
pp. 172988141985742 ◽  
Author(s):  
Bao Xi ◽  
Shuo Wang ◽  
Xuemei Ye ◽  
Yinghao Cai ◽  
Tao Lu ◽  
...  

In teleoperation, the operator is often required to command the motion of the remote robot and monitor its behavior. However, such an interaction demands a heavy workload from a human operator when facing with complex tasks and dynamic environments. In this article, we propose a shared control method to assist the operator in the manipulation tasks to reduce the workload and improve the efficiency. We adopt a task-parameterized hidden semi-Markov model to learn a manipulation skill from several human demonstrations. We utilize the learned model to predict the manipulation target given the current observed robotic motion trajectory and subsequently estimate the desired robotic motion given the current input of the operator. The estimated robotic motion is then utilized to correct the input of the operator to provide manipulation assistance. In addition, a set of virtual reality devices are used to capture the operator’s motion and display the vision feedback from the remote site. We evaluate our approach through two manipulation tasks with a dual-arm robot. The experimental results show the effectiveness of the proposed method.


2015 ◽  
Vol 12 (3) ◽  
pp. 361-371 ◽  
Author(s):  
Meiling Wang ◽  
Minzhou Luo ◽  
Tao Li ◽  
Marco Ceccarelli

2010 ◽  
Vol 97-101 ◽  
pp. 2407-2411 ◽  
Author(s):  
Li Bing Zhang ◽  
You Peng You ◽  
Jun He ◽  
Jun Liu

To enhance the velocity profile’s smoothness and machining efficiency of continuous short line segments, a velocity smooth control algorithm was presented based on the transition of cubic parametric spline curves. The transitional mathematical model was constructed, and an improved S-shaped jerk-limited acceleration/deceleration algorithm with look-ahead was adopted for smoother velocity profiles. The simulation and experiment results showed that machining efficiency was greatly improved, and smoother velocity profile was achieved, which approved the feasibility and validity of the proposed method.


2012 ◽  
Vol 468-471 ◽  
pp. 1224-1230 ◽  
Author(s):  
Guo Dong Chen

A dynamic hybrid position/force control method is developed for the coordination of two manipulators of a dual-arm robot to cope with the case of dual-arm tightly cooperate a common rigid object in the presence of environmental constraint. Begin with the definition of a group of generalized motion and force vectors used for task description, and by synthesizing the object dynamics and manipulator dynamics, an object-oriented dynamic equation of the dual-arm rigid coordination system is first derived, where relationships between object motion, internal stress force, and environmental contact force are explicitly presented. Furthermore, this equation and that of single arm dynamics in Cartesian still remain the same form. Based on this definition and description, the dynamic hybrid position/force control scheme for dual-arm symmetric coordination is then designed, and the decomposition and parallel realization of the control algorithm is also discussed. Several experiments have been done on two coordinated PUMA562 robot manipulators, which show that the proposed method works effectively, where the object motion and internal/external force can be simultaneously controlled during cooperation.


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