Thaneswer Patel

Towards virtual ergonomics: aviation and aerospace

Purpose – The purpose of this paper is to highlight state-of-the-art digital human modeling applications in aviation and aerospace industry, generate research interest and promote application of digital human modeling technology among audience of diverse background including researchers, students, trainees, etc. in academia and industry; designers; engineers; and ergonomists associated with aviation and aerospace sectors. Design/methodology/approach – Comprehensive literature search was performed and, subsequently, all publications identified were studied thoroughly at least by abstracts. Available information has been segregated under different headings and depicted systematically for easy understanding by readers. Findings – Virtual human modeling technology has been used in assessing reach and accessibility in aircraft cockpits, creating accurate posture libraries, performing vision analysis for pilots, determining design modifications to accommodate female users, predicting probable pilot behavior in ...

Software for performance prediction and matching of tractor-implement system

The matching of tractor-implement system is very difficult task in India because variety of tractor models ranging from 10 to 45kW is prevalent here. To overcome the problem of matching tractor-implement system, a decision support system (DSS) was developed in Visual Basic 6.0 programming language for 2-wheel drive (2WD) tractors. The DSS provides intuitive user interfaces by linking databases such as tractor parameters, tire and implement specifications, soil and operating conditions to support the decision for selection of tractor-implement system. DSS was validated for three different implements (2×30cm moldboard plow; 9-23cm field cultivator and 7-7 offset disc harrow (1.6m)). DSS which calculates draft, drawbar power, slip, tractive efficiency, coefficient of rolling resistance, coefficient of net traction, PTO power required, power utilization efficiency, specific fuel consumption based etc. on input data, can be used effectively in matching of tractor-implement system of various makes and models commercially available in India.

Impact of ergonomic intervention in manual orange harvester among the workers of hilly region in India

BACKGROUND Manual orange harvesting is very laborious, time consuming and unsafe operation whereas neither mechanical harvesting nor mechanized hand harvesting is possible in north-east India due to its hilly terrains. The awkward postures and repetitive nature of work in orange harvesting, demands a comfortable and appropriate hand harvester for hilly region. OBJECTIVE The purpose of this study was to develop a manual orange harvester for hilly regions considering the ergonomic parameters, and compare the performance with the existing models of the manual harvester. PARTICIPANTS In this study twenty healthy experienced orchard workers (10 male and 10 female) participated who did not have any previous functional musculoskeletal disorders. METHODS We developed a manual orange harvester by eliminating the problems associated with the existing harvesters. The developed model along with existing models was evaluated extensively in the field. During evaluations, heart rate of the subjects was measured and oxygen consumption was predicted to calculate the energy expenditure rate (EER) from the established relationship in the laboratory before the field experiments. Further, performance parameters of orange harvester i.e. plucking rate (PR), damaged quantity (DQ), plucking energy requirement (PER) and discomfort rating were also observed. RESULTS The PR was 425, 300 and 287 pieces per hour for the developed model (DM), first existing model (EM1) and second existing model (EM2), respectively. The DM showed lower PER (2.14 kJ/piece) followed by EM2 (2.95 kJ/piece) and EM1 (4.02 kJ/piece) which is considered as overall performance as it includes energy per unit of plucking. Further, the body part discomfort score revealed that DM was more comfortable in use followed by EM2 and EM1. CONCLUSIONS The performance of the DM was found better in terms of plucking rate, energy requirement and body part discomfort than the other existing models. Shoulders and neck are the most affected body parts where all subjects felt severe discomfort.

Redesign of Work-Accessories Towards Minimizing Awkward Posture and Reduction of Work Cycle Elements in an Indian Shop-Floor Workstation

Indian plastic processing industry comprises of Micro, Small and Medium Enterprises (MSMEs). Manual labor and locally designed workplace fixtures are observed in shop-floor workstations. Aim of present research was to identify incidence of musculoskeletal ailments and awkward working postures among workers in the granulator workstation and propose design modifications from physical ergonomics perspective. Combination of research techniques comprising of questionnaire study, postural assessment tools, statistical analysis, digital human modeling and method study were utilized to accomplish the stated objective. Significant occurrence of body part discomfort was observed. Workstation accessories designs were not in accordance with recommended guidelines. Workstation design and work methods were found incompatible with worker’s anthropometry and thus led to the prevalence of awkward working postures. Redesign of workstation accessories and subsequent modification of work methods, enabled improvement of working postures and reduction of work elements. Research methodology demonstrated in present study may be adopted by engineers/managers/supervisors in MSMEs towards implementing context specific human centric production systems.

Computer Simulation for Haulage Performance of Power Tiller

The presence of a large number of marginal and small land holdings in India has rendered the power tiller to be the most suitable farm equipment for field operations, in view of its compact size, profitability and versatility, but the transport work which is also required to carry the farm produce is yet to be proved. Keeping these in mind, user friendly software was developed for predicting the haulage performance of power tiller to meet requirements in educational and research organizations. The developed software requires input parameters such as power tiller, trolley and operating conditions. The developed software was validated by conducting experiments with a 6.7 kW power tiller using a suitable trolley on tarmacadam road at various payloads and road slopes. The draft, slip, fuel consumption and speed were measured and other haulage performance parameters were calculated based on measured values to validate the developed software. The results simulated by software indicate lower draft and slip in the range of 1-23 and 2-9% with respect to the experimental data, however, higher transport productivity was in the range of 3-12%.

Virtual Ergonomics Evaluation of a Design Concept of Manual Powered Portable Paddy Thresher Suitable for Hilly Region Agriculture

In the north-eastern states of India, paddy threshing is mostly carried out by traditional methods (such as bullock treading; beating by hand; crushing by foot, etc.) which require an enormous physical effort. These discomfited situations expose workers to many risk factors from ergonomics viewpoint. Therefore, it has been perceived that there is a necessity for systematic design and development towards low cost, manually operated, portable thresher considering the contextual need and topo-geographical conditions. The present research demonstrates the development of a concept CAD model of a portable pedal operated paddy thresher and evaluates the model through virtual ergonomic assessment. For virtual ergonomic evaluation of the CAD model of the thresher, customized digital manikins (5th, 50th and 95th percentile models of both male and female) were created in DELMIA software. These manikins represent anthropometric dimensions of the Assamese agricultural worker population. Postural comfort evaluation in virtual environment revealed that the proposed model was found to be acceptable. Following virtual ergonomic evaluation, it is expected that the development of real physical prototype would certainly be cost effective, user-friendly and efficient for small and marginal farmers in the rural area.

Statistical Interpretation of Collected Anthropometric Data of Agricultural Workers From Northeast India and Comparison With National and International Databases

OCCUPATIONAL APPLICATIONS Integrated applications of ergonomics and human factors are crucial for designers of agricultural tools and equipment, to improve performance and to enhance safety and productivity. Tools and equipment that do not fit properly with a users physical characteristics can cause discomfort and fatigue, and may result in low productivity and a higher incidence of accidents/injuries. For workers in the northeastern region of India, it is often not possible to manufacture or adapt user-compatible tools and equipment due to the limited availability of anthropometric and biomechanical data. The anthropometric database developed here is intended to address this lack of information and to assist in the development of anthropometrically compatible tools and equipment for the Assamese population (residents of “Assam,” a state from the northeast region of India). Statistical analyses (principal component and regression analysis) are also reported to help in identifying key anthropometric characteristics to be measured to derive other pertinent anthropometric variables. TECHNICAL ABSTRACT Background: Well-being, efficiency, and productivity of workers can depend substantially on the tools and equipment that they use. To enhance these, along with comfort and safety, tools and equipment should be compatible with the anthropometric characteristics of the intended user. Although anthropometric data are essential for effective equipment design, there is often little published anthropometric data for a given target population, and this is specifically the case for male Assamese agricultural workers. Purpose: To develop an anthropometric database (n = 130) of male agricultural workers within the “Kamrup” district of Assam. Collected data were compared with national and international databases to justify the need to develop local and regional databases. Method: Following a pilot study involving 20 participants, to evaluate the reliability of the anthropometric measurements, the main field study was conducted on 130 male agricultural workers (age range: 17 to 62 years) for a set of 26 body dimensions (along with age and body mass). Results: Mean (standard deviation) of age, stature, and body mass were 37.3 (11.7) years, 1,627.5 (45.9) mm and 55.2 (7.0) kg, respectively. Following principal component analysis of 25 anthropometric variables, six variables were representative of six principal components/factors. Linear regression analysis was used to predict some pertinent body dimensions. Some significant differences were found when comparing the current anthropometric data with databases from other zones of India (Northern, Southern, Eastern, Western, Central, and Northeast) and with male anthropometric data of other countries. Conclusions: Differences in anthropometric data within and between countries indicate that simple adoption of agricultural tools and equipment from specific regions might lead to occupational health hazards in the target population.

Context-specific design interventions in blending workstation: an ergonomics perspective

Work comprising of manual labor is a distinctive shop floor feature of Indian micro-, small- and medium-scale enterprises in manufacturing sectors. Investigations from an ergonomics perspective have not been performed in Indian plastic processing industries till date. Present paper aims to evaluate physical workload, psychosocial work environment, and subjective workload associated with blending workstations of small- and medium-scale plastic processing industries, in order to propose context-specific design interventions. An innovative combination of techniques featuring direct observation, questionnaire study, postural assessment, work study, virtual human modeling, and simulation were utilized toward achieving the stated aim. Prevalence of awkward work postures, symptoms of musculoskeletal ailments, and perception of high physical demand; urged for design interventions in these workstations. Following evaluation of existing working circumstances; concept model of modified blending workstation along with work accessories were assessed ergonomically in a virtual environment for making it human centric.