P.P. Ciufo, C.D. Cook and F. Naghdy
While robots have proved to be ideal for the manipulation of single articles accurately in three dimensions, they are not as cost‐effective in industry for tasks which require…
Abstract
While robots have proved to be ideal for the manipulation of single articles accurately in three dimensions, they are not as cost‐effective in industry for tasks which require simultaneous manipulations of several parts. In addition, changes in part geometry often necessitate the redesign of the gripping device, modification to the sensors and re‐examination of the grasping strategies to be used. These tasks are time consuming and add to the inefficiency of the approach.
Peng Wang, Luyu Liu, Fanghao Nan and RenQuan Dong
Assisted training using upper limb rehabilitation robots is beneficial for flaccid paralysis patients in recovering their functional abilities. In the assisted training mode, the…
Abstract
Purpose
Assisted training using upper limb rehabilitation robots is beneficial for flaccid paralysis patients in recovering their functional abilities. In the assisted training mode, the patient’s motor ability is limited by factors such as limb muscle tension, and it is prone for the rehabilitation robot to deviate from the prescribed training trajectory. A sliding mode control method based on a fixed time observer is proposed to address the problem of delayed trajectory tracking response of upper limb rehabilitation robots caused by external disturbances such as patient limbs.
Design/methodology/approach
First, aiming at the problem of estimating and compensating for external disturbances in the upper limb rehabilitation robot system, a fixed time observer was designed based on the robot’s dynamic model. Second, the composite sliding mode reaching law combining the smooth function and the power-exponential function is proposed to shorten the convergence time of system states in the startup phase, thereby reducing chattering in the control process and realizing the real-time tracking of the training trajectory by the control system.
Findings
The proposed method provides a solution for the trajectory tracking speed of upper limb rehabilitation robot controllers. In the circular trajectory tracking control, compared to the sliding-mode control method combined with the variable-exponential composite reaching law based on the fixed-time observer, the method in this paper reduces the time for the system state to reach the sliding surface by 0.89 s and improves the response speed by 0.66%.
Originality/value
The composite sliding mode approach law based on smooth function and power exponent function can reduce the time it takes for the system state to reach and remain on the sliding surface and improve the trajectory tracking speed of upper limb rehabilitation robots. This controller improves the accuracy of trajectory control and ensures the robustness of auxiliary rehabilitation training.
Details
Keywords
Ya'nan Lou, Pengkun Quan, Haoyu Lin, Zhuo Liang, Dongbo Wei and Shichun Di
This purpose of this paper is to design a peg-in-hole controller for a cable-driven serial robot with compliant wrist (CDSR-CW) using cable tensions and joint positions. The peg…
Abstract
Purpose
This purpose of this paper is to design a peg-in-hole controller for a cable-driven serial robot with compliant wrist (CDSR-CW) using cable tensions and joint positions. The peg is connected to the robot link through a CW. It is required that the controller does not rely on any external sensors such as 6-axis wrist force/torque (F/T) sensor, and only the compliance matrix’s estimated value of the CW is known.
Design/methodology/approach
First, the peg-in-hole assembly system based on a CDSR-CW is analyzed. Second, a characterization algorithm using micro cable tensions and joint positions to express the elastic F/T at the CW is established. Next, under the premise of only knowing the compliance matrix’s estimate, a peg-in-hole controller based on force/position hybrid control is proposed.
Findings
The experiment results show that the plug contact F/T can be tracked well. This verifies the validity and correctness of the characterization algorithm and peg-in-hole controller for CDSR-CWs in this paper.
Originality/value
First, to the authors’ knowledge, there is no relevant work about the peg-in-hole assembly task using a CDSR-CW. Besides, the proposed characterization algorithm for the elastic F/T makes the peg-in-hole controller get rid of the dependence on the F/T sensor, which expands the application scenarios of the peg-in-hole controller. Finally, the controller does not require an accurate compliance matrix, which also increases its applicability.
Details
Keywords
JENNIFER MACDOUGALL, J. MICHAEL BRITTAIN and ROBERT GANN
This paper provides an overview of the range and development of health informatics, with examples from the literature world wide covering the types of information involved, the…
Abstract
This paper provides an overview of the range and development of health informatics, with examples from the literature world wide covering the types of information involved, the areas of application, the impact of evidence based medicine and other professional issues, integrated information systems, and the needs of the public, patients and their carers. While medical informatics certainly comprises a major part of health informatics it is not the main focus of this paper. Medical informatics is the older term and involves the use of information technology and computing specifically for medical science research, and the diagnosis and treatment of disease involving, for example, X‐rays, imaging, resonance, and magnetic scanning techniques. Rather, the scope of this review is the literature relating to the wider concept of the management of information through the interdisciplinary application of information science and technology for the benefit of patients, scientists, managers, staff, and carers involved in the whole range of healthcare activity.
Edvardas Sadauskas and Bronius Baksys
The paper aims to theoretically and experimentally investigate vibratory peg-bush alignment using elastic vibrations of the peg, when the peg is axially excited by a pressed…
Abstract
Purpose
The paper aims to theoretically and experimentally investigate vibratory peg-bush alignment using elastic vibrations of the peg, when the peg is axially excited by a pressed piezoelectric vibrator on the upper end.
Design/methodology/approach
Experimental research of part alignment using elastic vibrations was performed and dependencies of alignment duration on excitation signal parameters and initial pressing force were defined for rectangular and circular cross-section parts. Mathematical model of two-mass dynamic systems with elastic contact model representing alignment process was created. Dependencies of system parameters on the alignment duration were obtained by numerically solving systems differential equations.
Findings
Theoretical and experimental investigation approved the usage of elastic vibrations for alignment of chamferless circular and rectangular cross-section parts. This novel method of part alignment compensates axial misalignment between mating parts by directional displacement of movably based bush.
Research limitations/implications
Impact and non-impact interaction between bush and peg is possible; however, only non-impact regime was investigated. Static and dynamic coefficients of friction between the parts are equivalent and do not depend on relative velocity of parts.
Practical implications
The results are useful in designing reliable and effective assembly equipment with vibratory assistance alignment for peg-bush operations, which do not require auxiliary sensors and feedback systems. Use of a piezoelectric resonator for peg excitation makes this system easily adaptable to the existing automated assembly equipment.
Originality/value
The proposed method is a new approach to vibratory alignment. The data obtained during investigation expand the insight of the physical processes that drive bush to the axial alignment direction.
Details
Keywords
Kamal Sharma, Varsha Shirwalkar and Prabir K. Pal
This paper aims to provide a solution to the first phase of a force-controlled circular Peg-In-Hole assembly using an industrial robot. The paper suggests motion planning of the…
Abstract
Purpose
This paper aims to provide a solution to the first phase of a force-controlled circular Peg-In-Hole assembly using an industrial robot. The paper suggests motion planning of the robot’s end-effector so as to perform Peg-In-Hole search with minimum a priori information of the working environment.
Design/methodology/approach
The paper models Peg-In-Hole search problem as a problem of finding the minima in depth profile for a particular assembly. Thereafter, various optimization techniques are used to guide the robot to locate minima and complete the hole search. This approach is inspired by a human’s approach of searching a hole by moving peg in various directions so as to search a point of maximum insertion which is same as the minima in depth profile.
Findings
The usage of optimization techniques for hole search allows the robot to work with minimum a priori information of the working environment. Also, the iterative nature of the techniques adapts to any disturbance during assembly.
Practical implications
The techniques discussed here are quite useful if a force-controlled assembly needs to be performed in a highly unknown environment and also when the assembly setup can get disturbed in between.
Originality/value
The concept is original and provides a non-conventional use of optimization techniques, not for optimization of some process directly but for an industrial robot’s motion planning.
Details
Keywords
Matthew Field, Zengxi Pan, David Stirling and Fazel Naghdy
The purpose of this paper is to provide a review of various motion capture technologies and discuss the methods for handling the captured data in applications related to robotics.
Abstract
Purpose
The purpose of this paper is to provide a review of various motion capture technologies and discuss the methods for handling the captured data in applications related to robotics.
Design/methodology/approach
The approach taken in the paper is to compare the features and limitations of motion trackers in common use. After introducing the technology, a summary is given of robotic‐related work undertaken with the sensors and the strengths of different approaches in handling the data are discussed. Each comparison is presented in a table. Results from the author's experimentation with an inertial motion capture system are discussed based on clustering and segmentation techniques.
Findings
The trend in methodology is towards stochastic machine learning techniques such as hidden Markov model or Gaussian mixture model, their extensions in hierarchical forms and non‐linear dimension reduction. The resulting empirical models tend to handle uncertainty well and are suitable for incrementally updating models. The challenges in human‐robot interaction today include expanding upon generalising motions to understand motion planning and decisions and build ultimately context aware systems.
Originality/value
Reviews including descriptions of motion trackers and recent methodologies used in analyzing the data they capture are not very common. Some exist, as has been pointed out in the paper, but this review concentrates more on applications in the robotics field. There is value in regularly surveying the research areas considered in this paper due to the rapid progress in sensors and especially data modeling.
Details
Keywords
Sophie McKenzie, Jo Coldwell-Neilson and Stuart Palmer
The purpose of this paper is to understand the career development and employability needs of undergraduate information technology (IT) students at an Australian University, and…
Abstract
Purpose
The purpose of this paper is to understand the career development and employability needs of undergraduate information technology (IT) students at an Australian University, and their relation to students’ career interest. While many factors and stakeholders contribute to student career development, this study focused specifically on the student experience. Social cognitive career theory (SCCT) is used as an approach to understand the students’ needs of career development and employability.
Design/methodology/approach
An online survey was completed by 126 IT students to record information about students’ career development and employability background and needs.
Findings
The results demonstrate that SCCT helps understand the factors that impact on IT students’ career development, with their outcome expectations and self-efficacy informed by prior studies in IT and their need for access to “IT professionals” to contribute towards their career interest. In addition, IT students rely on academic achievement and experiential learning, rather than career resources, to guide their career development and employability.
Research limitations/implications
The data collected in this study are limited to one discipline (IT) at one university, which necessarily limits the generalisability of the specific results.
Practical implications
Career development is a complex, life-stage-dependant and discipline-specific process that varies for every decision maker. This research makes an important contribution in presenting the IT student experience and demonstrates how an appropriate career development model can help understand students’ needs. This outcome will help educators better support IT students to build the career interest.
Originality/value
This study explored the often-overlooked student experience of career development, providing valuable insight into IT students’ needs.
Details
Keywords
Homayoun Najjaran and Andrew A. Goldenberg
Describes a dual‐arm mobile manipulator that can autonomously scan natural terrain using a typical handheld landmine detector in a manner similar to a human operator.
Abstract
Purpose
Describes a dual‐arm mobile manipulator that can autonomously scan natural terrain using a typical handheld landmine detector in a manner similar to a human operator.
Design/methodology/approach
Presents a terrain‐scanning robot that consists of two articulated arms mounted on an off‐road remotely operated vehicle. One arm carries a laser and four ultrasonic rangefinders to build a terrain map. The map is used in real time to generate an obstacle‐free path for the second arm that manipulates the landmine detector autonomously. The arms are mounted on the vehicle that is controlled by an operator from a safe distance. Motion planning and control of the robot is carried out using an embedded computer that is linked to a host computer to transmit the detector data and operator commands.
Findings
Finds that the terrain‐scanning robot can effectively manipulate a relatively large landmine detector on rugged terrain with undulations and obstacles.
Research limitations/implications
Proposes real‐time motion planning that may be equally applicable to other mobile manipulators.
Practical implications
Provides a technology that together with state‐of‐the‐art landmine sensors will offer a safe solution for detecting hidden landmines and clearing them from the postwar countries.
Originality/value
Introduces the concept of a dual‐arm mobile terrain scanning robot for landmine detection in off‐road missions and civilian areas where truck‐mounted detectors are inefficient.
Details
Keywords
Maryam Safari and Lee David Parker
This paper aims to provide a historical case study of strategic changes in accounting at an Australian university’s business school department during 1972-1992 when it was…
Abstract
Purpose
This paper aims to provide a historical case study of strategic changes in accounting at an Australian university’s business school department during 1972-1992 when it was repositioning itself in the early stages of major changes in the Australian and international tertiary accounting education environment. The study is conducted within the context of the university history within which the department operated as well as major government policy and global education shifts shaping university structures and focus.
Design/methodology/approach
This study offers a historical analysis of early stage changes in university focus at the business school’s accounting department, developed through departmental and university reports and oral history interviews. A narrative analytical methodology is adopted to portray a history of an academic accounting department in transition.
Findings
This case study illuminates the impacts of and responses to the beginning of marketisation and globalisation of higher education, and the commercialisation of universities and explains the strategic implementation processes in one university’s business school departmental during a period of significant formative change in the Australian accounting education landscape.
Originality/value
This study deepens our understanding of environmental, structural, educational and research changes at the operational departmental level of academic institutions, paying particular attention to the organisational culture and human capital dimensions.