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Article
Publication date: 1 April 2002

N.F. Edmondson and A.H. Redford

One of the first steps in designing a flexible assembly system is the selection of an appropriate manipulator. There are a number of different manipulator configurations…

Abstract

One of the first steps in designing a flexible assembly system is the selection of an appropriate manipulator. There are a number of different manipulator configurations which can be chosen depending on a variety of factors such as the assembly workspace layout, product size, weight, and component insertion direction.A number of methodologies have been written to help the selection of a manipulator for process cells. However, little work exists to aid the machine designer in the selection of an appropriate manipulator for flexible assembly. This paper examines the factors which affect this process.

Details

Industrial Robot: An International Journal, vol. 29 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 19 October 2015

GuoHua Gao, Yue Liu, Hao Wang, MingYang Song and Han Ren

The purpose of this paper is to present a new method to establish a kinematic model for a continuum manipulator, whose end can be controlled to move in a three-dimensional…

Abstract

Purpose

The purpose of this paper is to present a new method to establish a kinematic model for a continuum manipulator, whose end can be controlled to move in a three-dimensional workspace. A continuum manipulator has significant advantages over traditional, rigid manipulators in many applications because of its ability to conform to the environment. Moreover, because of its excellent flexibility, light weight, low energy consumption, low production cost, it has a number of potential applications in areas of earthquake relief, agricultural harvesting, medical facilities and space exploration.

Design/methodology/approach

This paper uses basic theory of material mechanics to deduct motion equations of the manipulator. Unlike other published papers, the manipulator is not based on segments tactics, but regarded as an integrated flexible system, which simplifies its kinematics modelling and motion controlling. The workspace of the manipulator is analysed by theoretical deducing and simulation modelling. For verification of the presented theory, simulation based on ADAMS software was implemented, while a prototype of the manipulator was developed. Both the software simulation and prototype experiment show that the theoretical analysis in this paper is reasonable. The manipulator can move accurately along the desired trajectories.

Findings

This paper developed a novel and fully continuous manipulator driven by steel wires. A kinematic model of the manipulator was established. The physical manipulator developed for verifying the kinematic model can effectively track the prescribed trajectory. The presented kinematic model agrees with not only the simulation but also with the experiment.

Research limitations/implications

The manipulator presented in this paper is constructed by steel wires. It possesses the advantages of structural continuity, high flexibility and low production cost. It can be extensively used in many fields, such as search and rescue robotic systems. The limitation of this research is that the dynamic model of the manipulator is not yet clear, which is one of the directions for future research.

Practical implications

The manipulator breaks through the limitation of the joint-type or flexible-link-type manipulator, which can also be extensively used in many fields such as search and rescue robotic systems.

Social implications

The manipulator developed in this paper, currently, is a prototype under the project of “Automatic Picking Manipulator Research”. It possesses a good market value.

Originality/value

The value of this research is that the manipulator breaks through the limitation of the joint-type or flexible-link-type manipulator and establishes the kinematic model for a fully continuous manipulator by a simple strategy. This is the first study that uses such a strategy for establishing the motion equations of a monolithic continuum manipulator.

Details

Industrial Robot: An International Journal, vol. 42 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 27 June 2022

Toan Van Nguyen, Jin-Hyeon Jeong and Jaewon Jo

Because mobile manipulators are unable to climb stairs, the elevator operation is a crucial capacity to help those kinds of robot systems work in modern multifloor…

Abstract

Purpose

Because mobile manipulators are unable to climb stairs, the elevator operation is a crucial capacity to help those kinds of robot systems work in modern multifloor buildings. Here, the elevator button manipulation is considered as an efficient approach to fulfill that requirement. Previously, some studies presented elevator button recognition algorithms while some others designed schemes for the button manipulation work. However, the mobile robot, the manipulator and the camera in their robot systems are asynchronous. Besides, the time-consuming calibration for the camera is inevitable, especially in changeable environments. This paper aims to present an alternative method for the elevator button manipulation to overcome mentioned shortcomings.

Design/methodology/approach

In this paper, the elevator button manipulation is conducted by using the visual-based self-driving mobile manipulator in which the autonomous mobile robot, the manipulator and the camera cooperate more efficiently. Namely, the mobile robot does not need to be located exactly in front of the elevator panel as the manipulator has the ability to adjust the initial frame of the camera based on the system kinematic synchronization. In addition, the proposed method does not require the real world coordinates of elevator buttons, but uniquely using their pixel positions. By doing this, not only is the projection from two-dimensional pixel coordinates to three-dimensional (3D) real world coordinates unnecessary, but also the calibration of the camera is not required.

Findings

The proposed method is experimentally verified by using a visual-based self-driving mobile manipulator. This robotic system is the integration of an autonomous mobile robot, a manipulator and a camera mounted on the end-effector of the manipulator.

Research limitations/implications

Because the surface of the elevator button panel is usually mirror-like, the elevator button detection is easily affected by the glare and the brightness of the environmental light condition.

Practical implications

This robot system can be used for the goods delivery or the patrol in modern multifloor buildings.

Originality/value

This paper includes three new features: simultaneously detecting and manipulating elevator buttons without the projection from pixel coordinates to 3D real world coordinates, a kinematic synchronization to help the robot system eliminate accumulated errors and a safe human-like elevator button manipulation.

Details

Industrial Robot: the international journal of robotics research and application, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 7 February 2022

Tao Song, Bo Pan, Guojun Niu and Yili Fu

This study aims to represent a novel closed-form solutions method based on the product of the exponential model to solve the inverse kinematics of a robotic manipulator

46

Abstract

Purpose

This study aims to represent a novel closed-form solutions method based on the product of the exponential model to solve the inverse kinematics of a robotic manipulator. In addition, this method is applied to master–slave control of the minimally invasive surgical (MIS) robot.

Design/methodology/approach

For MIS robotic inverse kinematics, the closed-form solutions based on the product of the exponential model of manipulators are divided into the RRR and RRT subproblems. Geometric and algebraic constraints are used as preconditions to solve two subproblems. In addition, several important coordinate systems are established on the surgical robot and master–slave mapping strategies are illustrated in detail. Finally, the MIS robot can realize master–slave control by combining closed-form solutions and master–slave mapping strategy.

Findings

The simulation of the instrument manipulator based on the RRR and RRT subproblems is executed to verify the correctness of the proposed closed-form solutions. The fact that the accuracy of the closed-form solutions is better than that of the compensation method is validated by the contrastive linear trajectory experiment, and the average and the maximum tracking errors are 0.1388 mm and 0.3047 mm, respectively. In the animal experiment, the average and maximum tracking error of the left instrument manipulator are 0.2192 mm and 0.4987 mm, whereas the average and maximum tracking error of the right instrument manipulator are 0.1885 mm and 0.6933 mm. The successful completion of the animal experiment comprehensively demonstrated the feasibility and reliability of the master–slave control strategy based on the novel closed-form solutions.

Originality/value

The proposed closed-form solutions are error-free in theory. The master–slave control strategy is not affected by calculation error when the closed-form solutions are used in the surgical robot. And the accuracy and reliability of the master–slave control strategy are greatly improved.

Details

Industrial Robot: the international journal of robotics research and application, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 14 December 2021

Vítor Tinoco, Manuel F. Silva, Filipe N. Santos, António Valente, Luís F. Rocha, Sandro A. Magalhães and Luis C. Santos

The motivation for robotics research in the agricultural field has sparked in consequence of the increasing world population and decreasing agricultural labor…

Abstract

Purpose

The motivation for robotics research in the agricultural field has sparked in consequence of the increasing world population and decreasing agricultural labor availability. This paper aims to analyze the state of the art of pruning and harvesting manipulators used in agriculture.

Design/methodology/approach

A research was performed on papers that corresponded to specific keywords. Ten papers were selected based on a set of attributes that made them adequate for review.

Findings

The pruning manipulators were used in two different scenarios: grapevines and apple trees. These manipulators showed that a light-controlled environment could reduce visual errors and that prismatic joints on the manipulator are advantageous to obtain a higher reach. The harvesting manipulators were used for three types of fruits: strawberries, tomatoes and apples. These manipulators revealed that different kinematic configurations are required for different kinds of end-effectors, as some of these tools only require movement in the horizontal axis and others are required to reach the target with a broad range of orientations.

Originality/value

This work serves to reduce the gap in the literature regarding agricultural manipulators and will support new developments of novel solutions related to agricultural robotic grasping and manipulation.

Details

Industrial Robot: the international journal of robotics research and application, vol. 49 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 27 July 2021

Omer Faruk Argin and Zeki Yagiz Bayraktaroglu

This paper aims to present a novel modular design framework for the haptic teleoperation of single-master/multiple-slave (SM/MS) systems with cooperating manipulators.

Abstract

Purpose

This paper aims to present a novel modular design framework for the haptic teleoperation of single-master/multiple-slave (SM/MS) systems with cooperating manipulators.

Design/methodology/approach

The user commands the remote-leader robot and the slave remote robot follows the leader in a leader–follower formation. The remote-slave is purely force-controlled. A virtual model of the remote environment is introduced between the local and remote environments through simulation software. Locally generated motion inputs are transmitted to the remote environment through the virtual model. A haptic coupling is designed in the virtual environment and the haptic feedback is transmitted to the user along with the forces measured in the remote environment. The controllers proposed in this work are experimentally evaluated with experienced and inexperienced users.

Findings

The proposed haptic interaction model contributes to the total force feedback and smoothens the high-frequency signals occurring at the physical interaction in the remote environment. Experimental results show that the implemented controllers including the proposed haptic interaction improve the teleoperation performances in terms of trajectory tracking. Furthermore, pure force control of the remote-slave is shown to enhance the robustness of the teleoperation against external disturbances. Satisfactory teleoperation performances are observed with both experienced and inexperienced users.

Originality/value

The proposed SM/MS teleoperation system involves a multi-purpose virtual simulator and a purely force-controlled remote-slave manipulator in a modular cooperative configuration. The uniquely defined structure of the proposed haptic coupling is used in modeling the interaction between the local and remote manipulators on the one hand, and between cooperating remote manipulators on the other.

Details

Industrial Robot: the international journal of robotics research and application, vol. 49 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 6 October 2021

Alok Ranjan Sahoo and Pavan Chakraborty

The purpose of this paper is to develop a tendon actuated variable stiffness double spring based continuously tapered multi-section flexible robot and study its capability…

Abstract

Purpose

The purpose of this paper is to develop a tendon actuated variable stiffness double spring based continuously tapered multi-section flexible robot and study its capability to achieve the desired bending and compression for inspection in cluttered environments.

Design/methodology/approach

Spring-based continuum manipulators get compressed while actuated for bending. This property can be used for the advantage in cluttered environments if one is able to control both bending and compression. Here, this paper uses a mechanics based model to achieve the desired bending and compression. Moreover, this study tries to incorporate the tapered design to help in independent actuation of the distal sections with minimal effects on proximal sections. This study is also trying to incorporate the double spring based design to minimize the number of spacers in the robot body.

Findings

The model was able to produce desired curvature at the tip section with less than 4.62% error. The positioning error of the manipulator is nearly 3.5% which is at par with the state-of-the-art manipulators for search and rescue operations. It was also found that the use of double spring can effectively reduce the number of spacers required. It can be helpful in smooth robot to outer world interaction without any kink. From the experiments, it has been found that the error of the kinematic model decreases as one moves from high radius of curvature to low radius of curvature. Error is maximum when the radius of curvature is infinity.

Practical implications

The proposed manipulator can be used for search operations in cluttered environments such as collapsed buildings and maintenance of heavy machineries in industries.

Originality/value

The novelty of this paper lies in the design and the proposed kinematics for a spring-based continuously tapered multi-section manipulator.

Details

Industrial Robot: the international journal of robotics research and application, vol. 49 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 6 January 2021

Ruolong Qi, Yuangui Tang and Ke Zhang

For some special manipulators such as the ones work at the space station, nuclear or some other unmanned environments, the overload, collision, vibration, temperature…

Abstract

Purpose

For some special manipulators such as the ones work at the space station, nuclear or some other unmanned environments, the overload, collision, vibration, temperature change or release of the internal stress would affect the structural parameters. And thus the operation precision might constantly decrease in long-term use. In these unmanned environments, the unattended manipulators should calibrate itself when they execute high precision operations or proceed self-maintenances. The purpose of this paper is to propose an automatic visual assistant on-line calibration (AVOC) method based on multi-markers.

Design/methodology/approach

A camera fixed on the end of the manipulator is used to measure one to three identification points, which forms an unstable multi-sensor eye-in-hand system. A Gaussian motion method which combines the linear quadratic regulator control and extended Kalman filter together is proposed to make the manipulator track the planned trajectories when its inaccurate structural parameters form uncertain motion errors. And a Monte-Carlo method is proposed to form a high precision and stable signal acquisition when the visual system has measurement errors and intermittent signal feedback. An automatic sampling process is adopted to select the optimal measurement points basing on their variances.

Findings

Data analysis and experiment results prove the efficiency and feasibility of the method proposed in this paper. With this method, the positioning accuracy is largely promoted from about 2 mm to 0.04–0.05 mm.

Originality/value

Experiments were carried out successfully on a manipulator in a life sciences glove box that will work at the Chinese space station. It is a low cost and efficient manipulator calibration method. The whole autonomic calibration process takes less than 10 min and requires no human intervention. In addition, this method not only can be used in the calibration of other unmanned articulated manipulator that works in deep ocean, nuclear industry or space but also be useful for the maintenance work in modern factories owing a lot of industrial robots.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 17 June 2021

Zeguo Yang, Mantian Li, Fusheng Zha, Xin Wang, Pengfei Wang and Wei Guo

This paper aims to introduce an imitation learning framework for a wheeled mobile manipulator based on dynamical movement primitives (DMPs). A novel mobile manipulator

Abstract

Purpose

This paper aims to introduce an imitation learning framework for a wheeled mobile manipulator based on dynamical movement primitives (DMPs). A novel mobile manipulator with the capability to learn from demonstration is introduced. Then, this study explains the whole process for a wheeled mobile manipulator to learn a demonstrated task and generalize to new situations. Two visual tracking controllers are designed for recording human demonstrations and monitoring robot operations. The study clarifies how human demonstrations can be learned and generalized to new situations by a wheel mobile manipulator.

Design/methodology/approach

The kinematic model of a mobile manipulator is analyzed. An RGB-D camera is applied to record the demonstration trajectories and observe robot operations. To avoid human demonstration behaviors going out of sight of the camera, a visual tracking controller is designed based on the kinematic model of the mobile manipulator. The demonstration trajectories are then represented by DMPs and learned by the mobile manipulator with corresponding models. Another tracking controller is designed based on the kinematic model of the mobile manipulator to monitor and modify the robot operations.

Findings

To verify the effectiveness of the imitation learning framework, several daily tasks are demonstrated and learned by the mobile manipulator. The results indicate that the presented approach shows good performance for a wheeled mobile manipulator to learn tasks through human demonstrations. The only thing a robot-user needs to do is to provide demonstrations, which highly facilitates the application of mobile manipulators.

Originality/value

The research fulfills the need for a wheeled mobile manipulator to learn tasks via demonstrations instead of manual planning. Similar approaches can be applied to mobile manipulators with different architecture.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 5 October 2020

Yinglong Chen, Wenshuo Li and Yongjun Gong

The purpose of this paper is to estimate the deformation of soft manipulators caused by obstacles accurately and the contact force and workspace can be also predicted.

Abstract

Purpose

The purpose of this paper is to estimate the deformation of soft manipulators caused by obstacles accurately and the contact force and workspace can be also predicted.

Design/methodology/approach

The continuum deformation of the backbone of the soft manipulator under contact is regarded as two constant curvature arcs and the curvatures are different according to the fluid pressure and obstacle location based on piecewise constant curvature framework. Then, this study introduces introduce the moment balance and energy conservation equation to describe the static relationship between driving moment, elastic moment and contact moment. Finally, simulation and experiments are carried out to verify the accuracy of the proposed model.

Findings

For rigid manipulators, environmental contact except for the manipulated object was usually considered as a “collision” which should be avoided. For soft manipulators, an environment is an important tool for achieving manipulation goals and it might even be considered to be a part of the soft manipulator’s end-effector in some specified situations.

Research limitations/implications

There are also some limitations to the presented study. Although this paper has made progress in the static modeling under environmental contact, some practical factors still limit the further application of the model, such as the detection accuracy of the environment location and the deformation of the contact surface.

Originality/value

Based on the proposed kinematic model, the bending deformation with environmental contact is discussed in simulations and has been experimentally verified. The comparison results show the correctness and accuracy of the presented SCC model, which can be applied to predict the slender deformation under environmental contact without knowing the contact force.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

1 – 10 of over 2000