Impact of auditory and visual distractors upon learning a manual assembly task in older workers

Using Maynard's description, an assembly task may be divided into various task elements like reach, select, grasp, move, position, and assemble (Ghosh and Helander, 1985). Activities such as “reach” and “move” are governed by biomechanics of body motions including human factors principles such as Fitt's law. This research investigated the effect of the structure of the assembly and the type of assembly instructions on performance. Two different product structures were used — a vertical assembly, built bottom-up, and a hierarchical assembly, consisting of several subassemblies. Two different instruction strategies were used: 1. top-down sequential instructions 2. No Instructions. The research showed that vertical products were easier for manual assembly, when provided with instructions. For all three dependant measures, there was no interaction effect between the two factors, namely product structure and instructions. Average time for completion was significant for both factors i.e. product structures ( F(1, 20) = 4.417, p < 0.0485) and instructions ( F(1, 20) = 5.886, p < 0.0248). However, time for learning was significant only for product structure factor ( F(1, 20) = 5.239, p < 0.033). Also, trials to learn was significant only for product structure factor ( F(1, 20) = 4.449, p < 0.047).

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Influence of Complexity and Noise on Mental Workload During a Manual Assembly Task

Communications in Computer and Information Science - Human Mental Workload: Models and Applications ◽

10.1007/978-3-030-62302-9_10 ◽

2020 ◽

pp. 147-174

Author(s):

Dominic Bläsing ◽

Manfred Bornewasser

Keyword(s):

Mental Workload ◽

Manual Assembly ◽

Assembly Task

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Biomechanical Evaluation of Passive Back-Support Exoskeletons in a Precision Manual Assembly Task: “Expected” Effects on Trunk Muscle Activity, Perceived Exertion, and Task Performance

Human Factors The Journal of the Human Factors and Ergonomics Society ◽

10.1177/0018720819890966 ◽

2020 ◽

Vol 62 (3) ◽

pp. 441-457 ◽

Cited By ~ 5

Author(s):

Saman Madinei ◽

Mohammad Mehdi Alemi ◽

Sunwook Kim ◽

Divya Srinivasan ◽

Maury A. Nussbaum

Keyword(s):

Task Performance ◽

Muscle Activity ◽

Perceived Exertion ◽

Trunk Muscle ◽

Low Back ◽

Manual Assembly ◽

Physical Demands ◽

Assembly Task ◽

Assembly Tasks ◽

And Task

Objective To assess the efficacy of two different passive back-support exoskeleton (BSE) designs, in terms of trunk muscle activity, perceived low-back exertion, and task performance. Background BSEs have the potential to be an effective intervention for reducing low-back physical demands, yet little is known about the impacts of different designs in work scenarios requiring varying degrees of symmetric and asymmetric trunk bending during manual assembly tasks. Method Eighteen participants (gender balanced) completed lab-based simulations of a precision manual assembly task using a “grooved pegboard.” This was done in 26 different conditions (20 unsupported; 6 supported, via a chair), which differed in vertical height, horizontal distance, and orientation. Results Using both BSEs reduced metrics of trunk muscle activity in many task conditions (≤47% reductions when using BackX™ and ≤24% reductions when using Laevo™). Such reductions, though, were more pronounced in the conditions closer to the mid-sagittal plane and differed between the two BSEs tested. Minimal effects on task completion times or ratings of perceived exertion were found for both BSEs. Conclusion Our findings suggest that using passive BSEs can be beneficial for quasi-static manual assembly tasks, yet their beneficial effects can be task specific and specific to BSE design approaches. Further work is needed, though, to better characterize this task specificity and to assess the generalizability of different BSE design approaches in terms of physical demands, perceived exertion, and task performance. Application These results can help guide the choice and application of passive BSE designs for diverse work scenarios involving nonneutral trunk postures.

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Evaluation of an Augmented Reality Instruction for a Complex Assembly Task

i-com ◽

10.1515/icom-2021-0005 ◽

2021 ◽

Vol 20 (1) ◽

pp. 63-72

Author(s):

Johannes Funk ◽

Ludger Schmidt

Keyword(s):

Augmented Reality ◽

Knowledge Transfer ◽

Manual Assembly ◽

Complex Assembly ◽

Assembly Task ◽

Rail Vehicles ◽

Instruction Type ◽

Low Costs ◽

Nasa Tlx ◽

Assembly Tasks

Abstract This study compares the use of a marker-based AR instruction with a paper instruction commonly used in manual assembly. Hypotheses were tested as to whether the instruction type affects assembly time, number of errors, usability, and employee strain. Instead of student participants and artificial assembly tasks (e. g. Lego assemblies), the study was conducted with 16 trainees in a real workplace for the assembly of emergency door release handles in rail vehicles. Five assembly runs were performed. Assembly times and assembly errors were determined from recorded videos. Usability (SUS) and strain (NASA-TLX) were recorded with questionnaires. After a slower assembly at the beginning, the AR group assembled significantly faster in the fifth run. The comparable number of errors, usability and strain make marker-based AR applications interesting for knowledge transfer in manual assembly, especially due to the easy entrance and low costs.

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