Caihua Xiong, Donggui Han and Youlun Xiong
The purpose of this paper is to design an integrated localization system for mobile robots in underground environments for exploring and rescuing tasks after incidents and…
Abstract
Purpose
The purpose of this paper is to design an integrated localization system for mobile robots in underground environments for exploring and rescuing tasks after incidents and detection of hazard gas in tunnels before ingress.
Design/methodology/approach
An integrated localization system mainly based on a strap‐down inertial measurement unit and a digital compass is designed for exploring and rescuing task in coal mines and tunnels. After a system model was founded, a filtering algorithm combining a wavelet‐based pre‐filter with unscented Kalman filters was developed for reckoning tracks of robots and localizing it.
Findings
Based on this research, an integrated localization system for robots in underground environments can be developed to explore some regions and rescue people. Although errors of localization exist, performance of the integrated system should be improved if some sensors and landmarks or maps of tunnels are introduced.
Originality/value
What is proposed in this paper is an integrated localization system used in underground environments. In this research, property of environments has been taken into account as an important disturbance when filtering thresholds were set.
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Caihua Xiong, Xianzhi Jiang, Ronglei Sun, XiaoLin Huang and Youlun Xiong
The purpose of this paper is to present the control methods of the exoskeleton robotic arm for stroke rehabilitation.
Abstract
Purpose
The purpose of this paper is to present the control methods of the exoskeleton robotic arm for stroke rehabilitation.
Design/methodology/approach
The robotic arm is driven by the pneumatic muscle actuators. The control system provides independent control for the robot. The joint axes of the robotic arm are arranged to mimic the natural upper limb workspace.
Findings
Findings are the classification of training modes and control methods of rehabilitation training, and the characters of both the instant spasm and the sustaining one.
Research limitations/implications
This paper is a preliminary step in the control system and the kinematical characteristics should be analyzed to achieve high precision of movement.
Originality/value
Based on a hierarchical structure, the control system allows the execution of sequence of switching control methods: position, force, force/position and impedance. Patient‐active‐robot‐passive and patient‐passive‐robot‐active (PPRA) training modes are also presented in this paper. In PPRA mode, the robotic arm can provide pre‐specified resistances on the patient's arm. Both instant and sustaining spasms are taken into account for safety.
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Xianzhi Jiang, Caihua Xiong, Ronglei Sun, Xiaolin Huang and Youlun Xiong
The purpose of this paper is to present the static and dynamic characteristics of the rehabilitation joint.
Abstract
Purpose
The purpose of this paper is to present the static and dynamic characteristics of the rehabilitation joint.
Design/methodology/approach
The rehabilitation joint is driven by pneumatic muscle actuators (PMAs). Rehabilitation robot is normally composed of several rehabilitation joints. The static and dynamic characteristics of the rehabilitation joint are important for control of the rehabilitation robot. Analysis and modeling of the rehabilitation joint is based on experiments.
Findings
The static model of the PMA is obtained by the method of curve fitting and achieved better precision compared to the existing representative models. A second‐order model fits the dynamic characteristic of the rehabilitation joint better than a first order one.
Research limitations/implications
The rehabilitation joint and the patient's joint combine to make an independent system, and the unstable factors of the patient's joint make it difficult in precisely modeling the rehabilitation joint.
Originality/value
The characteristics of the rehabilitation joint are all based on the data that were recorded in a series of with experiments, the same with modeling of the rehabilitation joint.
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Rong‐Lei Sun, Youlun Xiong, Runsheng Du and Han Ding
Multiple assembly sequences can increase the flexibility of assembly systems and consequently lead to better performance. The relationship between multiple assembly sequences and…
Abstract
Multiple assembly sequences can increase the flexibility of assembly systems and consequently lead to better performance. The relationship between multiple assembly sequences and their impact on the performance of assembly systems are studied. Based on the concept of operation flexibility, this paper presents a flexibility measure to evaluate each operation sequence. A flexibility‐based criterion is proposed to prioritize each operation, which is then used to guide the assembly scheduling. A simulation study demonstrates that when using the criterion, higher system flexibility is achieved and consequently better performance of the assembly systems is obtained.
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The purpose of this paper is to clarify the relationship between automated assembly and mass production environments such as the manufacture of cars, airplanes and white goods and…
Abstract
Purpose
The purpose of this paper is to clarify the relationship between automated assembly and mass production environments such as the manufacture of cars, airplanes and white goods and methods of modelling and simulation. Even in this environment high‐level automated assembly is restricted to the original equipment manufacturers where production volumes are high and flexibility and the ability to quickly reconfigure systems are not major drivers. It proposes modelling of the fixing/assembly process and outlining why and how new methods are important throughout the manufacturing process. The paper aims to expand the domain of co operation of different research institutes, universities and companies.
Design/methodology/approach
The paper focuses on typically, fixture design, which involves the identification of clamp, locator, and support points, and the selection of corresponding fixture elements for their respective functions. In addition, the automation of fixture design activities in manufacturing is an important research area, which aims to achieve the integration of design and manufacturing. The most commonly used methods are pointed out.
Findings
The paper summarizes the main modelling and simulation methods applied to new fixing and assembly processes.
Research limitations/implications
Because of the chosen research approach, the paper is more general.
Practical implications
The paper includes implications for the development of a powerful new fixing method applied in the automotive and aerospace industry, which is important for stability and easy change in a rough manufacturing environment.
Originality/value
This paper fulfils an identified need to study how new fixing methods can improve motorcar and aerospace manufacturing.
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Rong‐Lei Sun, Han Ding, Youlun Xiong and Runsheng Du
Dispatching rule‐based scheduling is a kind of dynamic scheduling commonly used in real world applications. Because of the lack of scheduling objective, it cannot optimize the…
Abstract
Dispatching rule‐based scheduling is a kind of dynamic scheduling commonly used in real world applications. Because of the lack of scheduling objective, it cannot optimize the specific performances at which shop managers aim in the current production period. To overcome the limitations of the dispatching rule‐based scheduling, an iterative learning scheduling scheme is proposed in this paper. A scheduling objective function, which reflects the performance criteria in which the shop managers are most interested, is established and used to guide the optimization of the crucial performances. According to the value of the scheduling objective obtained from the last simulation period, the parameters are adjusted so as to decrease the objective during the next simulation period. Experimental results show that the iterative learning scheduling overcomes the limitations of the dispatching rule‐based scheduling and achieves higher performances.
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Pinkuan Liu, Yulin Wang and Jun Wu
The purpose of this paper is to discuss the design and fabrication of magnetic couplings to use for vacuum robots. The permanent magnetic coupling (PMC) is appropriate for torque…
Abstract
Purpose
The purpose of this paper is to discuss the design and fabrication of magnetic couplings to use for vacuum robots. The permanent magnetic coupling (PMC) is appropriate for torque transmission in ultrahigh vacuum and highly clean environments. However, conventional structures of PMC are always unsuitable to use for vacuum robots.
Design/methodology/approach
Two types of design scheme for radial magnetic couplings are introduced and compared. The major characteristic of the novel design scheme is that the inner part uses a nonmagnetic mantle to enclose the magnets and yoke, and the outer part uses two end closures to position magnets. The locating groove on the end closure may be manufactured as T‐shape or dovetail shape.
Findings
The 3D finite element analysis simulation results and experimental studies have demonstrated that the proposed Design B had a lower contamination rate and a higher transmission efficiency than the Design A.
Research limitations/implications
The limitation of the research to date is that issues of control, path‐planning, and communication have not yet been addressed.
Practical implications
The proposed PMC is successfully applied in vacuum robots which uses combined direct drive techniques and magnetic transmit techniques.
Originality/value
These results suggest that the proposed PMC is suitable for using in vacuum robots.
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Hong Yue, Kai Li, Haiwen Zhao and Yi Zhang
The purpose of this paper is to introduce structured light image processing technology into pipeline welding automation projects, and develop a vision‐based pipeline girth‐welding…
Abstract
Purpose
The purpose of this paper is to introduce structured light image processing technology into pipeline welding automation projects, and develop a vision‐based pipeline girth‐welding robot. The welding torch can accurately track the weld and complete the omni‐orientation welding automatically.
Design/methodology/approach
Weld image processing adopts the base theory including Laplacian of Gaussian filter, neighbourhood mean filter, largest variance threshold segmentation and morphologic, etc. obtains good effect of weld recognition.
Findings
The paper uses a vision sensor to achieve the weld character's recognition and extraction, directly control the robot tracking weld to complete automation welding. Compared with the existing pipeline welding devices, it does not need the lay orbit or plot tracking mark, which can shorten the assistant time to improve the productivity.
Practical implications
The research findings can satisfy the need of whole‐directional automation welding for large diameter transportation pipe's circular abutting weld. It fits for the automation welding for the long‐distance transportation pipe of petroleum, natural gas, and water.
Originality/value
Aiming at the character recognition and extract of V‐type weld, the method combining the neighbourhood mean filter algorithm with the largest variance threshold segmentation is proposed to obtain the quick weld image processing speed.
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Jie Zhao, Gangfeng Liu, Jihong Yan and Xizhe Zang
The purpose of this paper is to present a new scout robot that tries to combine the hopping movement and the wheeling movement to greatly enlarge the scope of robot's activities.
Abstract
Purpose
The purpose of this paper is to present a new scout robot that tries to combine the hopping movement and the wheeling movement to greatly enlarge the scope of robot's activities.
Design/methodology/approach
A five‐shank hopping mechanism was employed to build the wheeling‐hopping combination scout robot. The non‐linear character of the five‐shank hopping mechanism was analyzed and then used in the proposed non‐linear spring‐mass model for the robot.
Findings
The rules of robot's movement were deduced, influencing factors of the jumping height were analyzed and the countermeasure was adopted. Simulations and an experiment of the robot's movement showed that the robot has strong locomotivity and survival ability.
Originality/value
A five‐shank hopping mechanism is proposed, analyzed and combined with wheeling movement to enhance the locomotivity and survival ability of scout robot.