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Article
Publication date: 8 June 2021

Mohamed Raessa, Weiwei Wan and Kensuke Harada

This paper aims to present a hierarchical motion planner for planning the manipulation motion to repose long and heavy objects considering external support surfaces.

Abstract

Purpose

This paper aims to present a hierarchical motion planner for planning the manipulation motion to repose long and heavy objects considering external support surfaces.

Design/methodology/approach

The planner includes a task-level layer and a motion-level layer. This paper formulates the manipulation planning problem at the task level by considering grasp poses as nodes and object poses for edges. This paper considers regrasping and constrained in-hand slip (drooping) during building graphs and find mixed regrasping and drooping sequences by searching the graph. The generated sequences autonomously divide the object weight between the arm and the support surface and avoid configuration obstacles. Cartesian planning is used at the robot motion level to generate motions between adjacent critical grasp poses of the sequence found by the task-level layer.

Findings

Various experiments are carried out to examine the performance of the proposed planner. The results show improved capability of robot arms to manipulate long and heavy objects using the proposed planner.

Originality/value

The authors’ contribution is that they initially develop a graph-based planning system that reasons both in-hand and regrasp manipulation motion considering external supports. On one hand, the planner integrates regrasping and drooping to realize in-hand manipulation with external support. On the other hand, it switches states by releasing and regrasping objects when the object is in stably placed. The search graphs' nodes could be retrieved from remote cloud servers that provide a large amount of pre-annotated data to implement cyber intelligence.

Details

Assembly Automation, vol. 41 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 2 October 2019

B.M. Sayed, Mohamed Fanni, Mohamed S. Raessa and Abdelfatah Mohamed

This paper aims to design and control of a novel compact transportation system called the “wearable vehicle”. The wearable vehicle allows for traversing all types of terrains…

Abstract

Purpose

This paper aims to design and control of a novel compact transportation system called the “wearable vehicle”. The wearable vehicle allows for traversing all types of terrains while transporting one's luggage in a comfortable and efficient manner.

Design/methodology/approach

The proposed design consists of a lower limb exoskeleton carrying two motorized wheels and two free wheels installed alongside its feet. This paper presents a detailed description of the system with its preliminary design and finite element analysis. Moreover, the system has been optimally designed to decrease wearable vehicle’s total weight, consequently leading to a reduction in motor size. Finally, two controllers have been designed to achieve stable operation of the wearable vehicle while walking. A PD controller with gravity compensation has been designed to ensure that the wearable vehicle tracks human motion, while a PID controller has been designed to ensure that the zero moment point is close to the center of the system’s support polygon.

Findings

Experimental tests were carried out to check the wearable vehicle concept. The obtained results prove the feasibility of the proposed wearable vehicle from the design, dynamics and control viewpoints.

Practical implications

This proposed wearable vehicle’s purpose is for traveling faster with less effort than normal walking. When a human comes across a flat open ground, the wearable vehicle can be used as a vehicle. However, when a human enters crowded traffic, an unstructured area or other obstacles like stairs, the vehicle can be switched into walking mode.

Originality/value

The wearable vehicle has seven DOFs exoskeletons, two motorized wheels, two free wheels and a foldable seat. It is used as a vehicle via its motorized and free wheels to travel fast with minimal effort. In addition, the human can switch easily into walking mode, if there is unstructured terrain to be traversed. Furthermore, an illustration of system's mechanisms and main feature parameters are presented to become acquainted with the ultimate benefits of the new system.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 21 April 2020

Noha Elberry and Khaled Hussainey

The authors examine the impact of corporate investment efficiency on corporate voluntary disclosure for a sample of UK non-financial companies.

1209

Abstract

Purpose

The authors examine the impact of corporate investment efficiency on corporate voluntary disclosure for a sample of UK non-financial companies.

Design/methodology/approach

The authors use a sample of FTSE All-Share firms for the period of 2007–2014. Disclosure scores are collected from Corporate Financial Information Environment (CFIE). They follow Biddle et al. (2009) and Chen et al. (2011) in measuring corporate investment efficiency.

Findings

The authors find that high level of performance-related disclosure is associated with high level of corporate investment efficiency, while high level of good news information is associated with low level of corporate investment efficiency. They also find evidence on a bidirectional relation between disclosure and corporate investment efficiency.

Research limitations/implications

The authors’ findings would be of importance to stakeholders and corporations. Stakeholders' investment decisions could be facilitated by understanding the disclosures provided by their firms and how these firms' performance is presented. Corporations become aware of the language which must be used to signal their performance.

Practical implications

Corporations become aware of the language which must be used in their disclosures. As firms may reflect their efficient investments but not in the form of good news in order to avoid revealing their competitive advantage to competitors.

Originality/value

This paper adds to disclosure studies by introducing a new variable, corporate investment efficiency, as a determinant of corporate disclosure practice.

Details

Journal of Applied Accounting Research, vol. 21 no. 2
Type: Research Article
ISSN: 0967-5426

Keywords

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