Control of redundant robots using learned models: An operational space control approach

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.

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Learning Forward Models for the Operational Space Control of Redundant Robots

Studies in Computational Intelligence - From Motor Learning to Interaction Learning in Robots ◽

10.1007/978-3-642-05181-4_8 ◽

2010 ◽

pp. 169-192 ◽

Cited By ~ 11

Author(s):

Camille Salaün ◽

Vincent Padois ◽

Olivier Sigaud

Keyword(s):

Forward Models ◽

Redundant Robots ◽

Operational Space ◽

Learning Forward

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An Extended Jacobian-Based Formulation for Operational Space Control of Kinematically Redundant Robot Manipulators With Multiple Subtask Objectives: An Adaptive Control Approach

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4042464 ◽

2019 ◽

Vol 141 (5) ◽

Cited By ~ 1

Author(s):

Kamil Cetin ◽

Enver Tatlicioglu ◽

Erkan Zergeroglu

Keyword(s):

Stability Analysis ◽

Tracking Control ◽

Robot Manipulators ◽

Robot Dynamics ◽

Simulation Studies ◽

Matrix Formulation ◽

Redundant Robot ◽

Control Approach ◽

Operational Space ◽

The Stability

In this study, an extended Jacobian matrix formulation is proposed for the operational space tracking control of kinematically redundant robot manipulators with multiple subtask objectives. Furthermore, to compensate the structured uncertainties related to the robot dynamics, an adaptive operational space controller is designed, and then, the corresponding stability analysis is presented for kinematically redundant robot manipulators. Specifically, the proposed method is concerned with not only the stability of operational space objective but also the stability of multiple subtask objectives. The combined stability analysis of the operational space objective and the subtask objectives are obtained via Lyapunov based arguments. Experimental and simulation studies are presented to illustrate the performance of the proposed method.

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Simplified Motion Control of a Vehicle manipulator for the Coordinated Mobile Manipulation

Defence Science Journal ◽

10.14429/dsj.70.14119 ◽

2020 ◽

Vol 70 (1) ◽

pp. 72-81 ◽

Cited By ~ 1

Author(s):

Swati Mishra ◽

Santhakumar Mohan ◽

Santosh Kumar Vishvakarma

Keyword(s):

Motion Control ◽

Experimental Testing ◽

Kinematic Control ◽

Control Approach ◽

Operational Space ◽

Control Scheme ◽

Manipulator Arm ◽

The Given ◽

Pseudo Inverse ◽

Kinematic Motion

This paper considers a resolved kinematic motion control approach for controlling a spatial serial manipulator arm that is mounted on a vehicle base. The end-effector’s motion of the manipulator is controlled by a novel kinematic control scheme, and the performance is compared with the well-known operational-space control scheme. The proposed control scheme aims to track the given operational-space (end-effector) motion trajectory with the help of resolved configuration-space motion without using the Jacobian matrix inverse or pseudo inverse. The experimental testing results show that the suggested control scheme is as close to the conventional operational-space kinematic control scheme.

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ControlIt! — A Software Framework for Whole-Body Operational Space Control

International Journal of Humanoid Robotics ◽

10.1142/s0219843615500401 ◽

2016 ◽

Vol 13 (01) ◽

pp. 1550040 ◽

Cited By ~ 9

Author(s):

Chien-Liang Fok ◽

Gwendolyn Johnson ◽

John D. Yamokoski ◽

Aloysius Mok ◽

Luis Sentis

Keyword(s):

Upper Body ◽

Whole Body ◽

Software Framework ◽

Physical Constraints ◽

Lower Priority ◽

Redundant Robots ◽

Operational Space ◽

Floating Base ◽

Position Task ◽

Product Disassembly

Whole Body Operational Space Control (WBOSC) enables floating-base highly redundant robots to achieve unified motion/force control of one or more operational space objectives while adhering to physical constraints. It is a pioneering algorithm in the field of human-centered Whole-Body Control (WBC). Although there are extensive studies on the algorithms and theory behind WBOSC, limited studies exist on the software architecture and APIs that enable WBOSC to perform and be integrated into a larger system. In this paper, we address this by presenting ControlIt!, a new open-source software framework for WBOSC. Unlike previous implementations, ControlIt! is multi-threaded to increase maximum servo frequencies using standard PC hardware. A new parameter binding mechanism enables tight integration between ControlIt! and external processes via an extensible set of transport protocols. To support a new robot, only two plugins and a URDF model is needed — the rest of ControlIt! remains unchanged. New WBC primitives can be added by writing Task or Constraint plugins. ControlIt!’s capabilities are demonstrated on Dreamer, a 16-DOF torque controlled humanoid upper body robot containing both series elastic and co-actuated joints, and using it to perform a product disassembly task. Using this testbed, we show that ControlIt! can achieve average servo latencies of about 0.5[Formula: see text]ms when configured with two Cartesian position tasks, two orientation tasks, and a lower priority posture task. This is 10 times faster than the 5[Formula: see text]ms that was achieved using UTA-WBC, the prototype implementation of WBOSC that is both application and platform-specific. Variations in the product’s position is handled by updating the goal of the Cartesian position task. ControlIt!’s source code is released under LGPL and we hope it will be adopted and maintained by the WBC community for the long term as a platform for WBC development and integration.

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Comparison of null-space and minimal null-space control algorithms

Robotica ◽

10.1017/s0263574707003402 ◽

2007 ◽

Vol 25 (5) ◽

pp. 511-520 ◽

Cited By ~ 15

Author(s):

Bojan Nemec ◽

Leon Žlajpah ◽

Damir Omrčen

Keyword(s):

Degrees Of Freedom ◽

Null Space ◽

Space Velocity ◽

Control Algorithms ◽

Robot Arm ◽

Velocity Control ◽

Redundant Robots ◽

Operational Space ◽

Space Projection ◽

The Stability

SUMMARYThis paper deals with the stability of null-space velocity control algorithms in extended operational space for redundant robots. We compare the performance of the control algorithm based on the minimal null-space projection and generalized-inverse-based projection into the Jacobian null-space. We show how the null-space projection affects the performance of the null-space tracking algorithm. The results are verified with the simulation and real implementation on a redundant mobile robot composed of 3 degrees of freedom (DOFs) mobile platform and 7-DOF robot arm.

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Shape Sensing of Hyper-Redundant Robots Using an AHRS IMU Sensor Network

Sensors ◽

10.3390/s22010373 ◽

2022 ◽

Vol 22 (1) ◽

pp. 373

Author(s):

Ciprian Lapusan ◽

Olimpiu Hancu ◽

Ciprian Rad

Keyword(s):

Sensor Network ◽

Kinematic Model ◽

Sensory System ◽

Feedback System ◽

Computational Time ◽

Redundant Robots ◽

Testing Method ◽

Operational Space ◽

Novel Approach ◽

Shape Sensing

The paper proposes a novel approach for shape sensing of hyper-redundant robots based on an AHRS IMU sensor network embedded into the structure of the robot. The proposed approach uses the data from the sensor network to directly calculate the kinematic parameters of the robot in modules operational space reducing thus the computational time and facilitating implementation of advanced real-time feedback system for shape sensing. In the paper the method is applied for shape sensing and pose estimation of an articulated joint-based hyper-redundant robot with identical 2-DoF modules serially connected. Using a testing method based on HIL techniques the authors validate the computed kinematic model and the computed shape of the robot prototype. A second testing method is used to validate the end effector pose using an external sensory system. The experimental results obtained demonstrate the feasibility of using this type of sensor network and the effectiveness of the proposed shape sensing approach for hyper-redundant robots.

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Trilateral teleoperation control of kinematically redundant robotic manipulators

The International Journal of Robotics Research ◽

10.1177/0278364911401053 ◽

2011 ◽

Vol 30 (13) ◽

pp. 1643-1664 ◽

Cited By ~ 28

Author(s):

Pawel Malysz ◽

Shahin Sirouspour

Keyword(s):

Joint Space ◽

Redundancy Resolution ◽

High Priority Task ◽

Control Approach ◽

Task Control ◽

Lower Priority ◽

Redundant Robots ◽

Priority Task ◽

Closed Chain ◽

Lower Priority Task

Teleoperation control of kinematically redundant robots requires a strategy for resolving their redundancy. A trilateral two-master/one-slave control approach is proposed for delay-free applications in which the first master controls a primary task control frame, e.g. the slave end-effector frame; meanwhile, another master device can manipulate a secondary task frame attached to the slave robot, e.g. to avoid collision with obstacles in the task environment. Any remaining degrees of motion are resolved autonomously. Teleoperation control is achieved in three steps employing joint-space Lyapunov-based adaptive motion/force controllers, a velocity-level redundancy resolution method, and task-space coordinating reference commands. Priority can be given to either the primary or secondary control frame so that the high-priority task can be transparently carried out without interference from the other task. Whenever applicable, the lower-priority task control frame would be restricted to the natural constraints imposed by prioritization or otherwise, decoupling between the tasks is achieved with the use of an arbitrarily weighted pseudo-inverse. Experiments with a planar teleoperation system consisting of two master devices controlling a closed-chain four degree-of-motion redundant slave robot show the feasibility of the approach.

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