An Integrated Model of Static and Dynamic Measurement for Seat Discomfort

Daruis, Dian Darina Indah,Deros, Baba Md,Nor, Mohd Jailani Mohd,Hosseini, Mohammad Korean Institute of Industrial Engineers 2011 Industrial Engineeering & Management Systems Vol.10 No.3

A driver interacts directly with the car seat at all times. There are ergonomic characteristics that have to be followed to produce comfortable seats. However, most of previous researches focused on either static or dynamic condition only. In addition, research on car seat development is critically lacking although Malaysia herself manufactures its own car. Hence, this paper integrates objective measurements and subjective evaluation to predict seat discomfort. The objective measurements consider both static and dynamic conditions. Steven's psychophysics power law has been used in which after expansion; ${\psi}\;=\;a+b{\varphi}_s^{\alpha}+c{\varphi}_v^{\beta}$ where ${\psi}$ is discomfort sensation, ${\varphi}_s^{\alpha}$ is static modality with exponent ${\alpha}$ and ${\varphi}_v^{\beta}$ is dynamic modality with exponent ${\beta}$. The subjects in this study were local and the cars used were Malaysian made compact car. Static objective measurement was the seat pressure distribution measurement. The experiment was carried out on the driver's seat in a real car with the engine turned off. Meanwhile, the dynamic objective measurement was carried out in a moving car on real roads. During pressure distribution and vibration transmissibility experiments, subjects were requested to evaluate their discomfort levels using vehicle seat discomfort survey questionnaire together with body map diagram. From subjective evaluations, seat pressure and vibration dose values exponent for static modality ${\alpha}$ = 1.51 and exponent for dynamic modality ${\beta}$ = 1.24 were produced. The curves produced from the $E_{q.s}$ showed better $R_{-sq}$ values (99%) when both static and dynamic modalities were considered together as compared to Eq. with single modality only (static or dynamic only R-Sq = 95%). In conclusion, car seat discomfort prediction gives better result when seat development considered both static and dynamic modalities; and using ergonomic approach.

REDESIGNING VEHICLE INTERIOR: A CASE STUDY ON THE DRIVER SEAT ON YOUNG ADULTS ANTHROPOMETRY DATA

Daruis, D.D.I,Khamis, K.,Mohamad, D.,Dzulkarnain, I.A. 대한인간공학회 2020 대한인간공학회 학술대회논문집 Vol.2020 No.10

An Integrated Model of Static and Dynamic Measurement for Seat Discomfort

Dian Darina Indah Daruis,Baba Md Deros,Mohd Jailani Mohd Nor,Mohammad Hosseini 대한산업공학회 2011 Industrial Engineeering & Management Systems Vol.10 No.3

A driver interacts directly with the car seat at all times. There are ergonomic characteristics that have to be followed to produce comfortable seats. However, most of previous researches focused on either static or dynamic condition only. In addition, research on car seat development is critically lacking although Malaysia herself manufactures its own car. Hence, this paper integrates objective measurements and subjective evaluation to predict seat discomfort. The objective measurements consider both static and dynamic conditions. Steven"s psychophysics power law has been used in which after expansion; ψ = a+bφs<SUP>α</SUP>+cφv<SUP>β</SUP> where ψ is discomfort sensation, φs<SUP>α</SUP> is static modality with exponent α and φv<SUP>β</SUP> is dynamic modality with exponent β. The subjects in this study were local and the cars used were Malaysian made compact car. Static objective measurement was the seat pressure distribution measurement. The experiment was carried out on the driver"s seat in a real car with the engine turned off. Meanwhile, the dynamic objective measurement was carried out in a moving car on real roads. During pressure distribution and vibration transmissibility experiments, subjects were requested to evaluate their discomfort levels using vehicle seat discomfort survey questionnaire together with body map diagram. From subjective evaluations, seat pressure and vibration dose values exponent for static modality α=1.51 and exponent for dynamic modality β=1.24 were produced. The curves produced from the Eq.s showed better R-sq values (99%) when both static and dynamic modalities were considered together as compared to Eq. with single modality only (static or dynamic only R-Sq = 95%). In conclusion, car seat discomfort prediction gives better result when seat development considered both static and dynamic modalities; and using ergonomic approach.

Evaluation of Car Seat Using Reliable and Valid Vehicle Seat Discomfort Survey

Deros, Baba Md.,Daruis, Dian Darina Indah,Nor, Mohd Jailani Mohd Korean Institute of Industrial Engineers 2009 Industrial Engineeering & Management Systems Vol.8 No.2

Subjective evaluation has always been regarded as a branch of social science research. Hence, in scientific and especially engineering points of view, its development is always taken for granted despite the importance of its effects on the design and development decisions. In the past, at least two automotive seat survey questionnaires have been developed with high statistical validity and reliability. Nonetheless, both were not local while subjective perception very much depends on demographic background factors. It is felt that since vehicle seat comfort is an important aspect in a seat design, a local sense should be put into the survey that is used as the subjective tool. The proposed vehicle seat discomfort survey questionnaire was developed in dual languages; English and Malay. Malay language is the national language of Malaysia, where the survey was tested. Beside inputs from literatures, key informant interviews helped in establishing the appropriate terms used as survey items. Three experimental runs on two different seats by 22 paid subjects showed that the developed questionnaire is reliable and valid. Furthermore, criterion validity analysis on the survey and previously developed survey showed significant correlation at 0.01 significance level.

Evaluation of Car Seat Using Reliable and Valid Vehicle Seat Discomfort Survey

Baba Md. Deros,Dian Darina Indah Daruis,Mohd Jailani Mohd Nor 대한산업공학회 2009 Industrial Engineeering & Management Systems Vol.8 No.2

Subjective evaluation has always been regarded as a branch of social science research. Hence, in scientific and especially engineering points of view, its development is always taken for granted despite the importance of its effects on the design and development decisions. In the past, at least two automotive seat survey questionnaires have been developed with high statistical validity and reliability. Nonetheless, both were not local while subjective perception very much depends on demographic background factors. It is felt that since vehicle seat comfort is an important aspect in a seat design, a local sense should be put into the survey that is used as the subjective tool. The proposed vehicle seat discomfort survey questionnaire was developed in dual languages; English and Malay. Malay language is the national language of Malaysia, where the survey was tested. Beside inputs from literatures, key informant interviews helped in establishing the appropriate terms used as survey items. Three experimental runs on two different seats by 22 paid subjects showed that the developed questionnaire is reliable and valid. Furthermore, criterion validity analysis on the survey and previously developed survey showed significant correlation at 0.01 significance level.

Adaptive robust control for fully electric pitch system of tank with dynamic friction compensation

Darui Lin,Xiuye Wang,Guolai Yang,Shusen Yuan,Qinqin Sun 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10

This article addresses a problem of dynamic friction compensation for fully electric pitch system of tank based on modified LuGre model. Aiming to design a controller to realize friction modeling and compensating of fully electric pitch system of tank in large range of motion speeds. First, a nonlinear mathematical model including modified friction model and time-varying disturbance is established for fully electric pitch system of tank. Second, a disturbance compensation robust feedback term is designed to compensate the time-varying disturbance to reduce the impact of the disturbance on the control performance by adaptive estimation of the upper bound of the unmodeled disturbance. Third, the uncertainty parameters and friction state of the system are estimated and the adaptive control law combined with friction compensation is designed to reduce the sensitivity of the system to parameter uncertainty and nonlinear friction. Fourth, the global stability of the system is proved by Lyapunov stability theory. Finally, a virtual prototype model of tank moving based on friction disturbance and road excitation is established. The co-simulation results show that the proposed method can accurately estimate and compensate model parameters, nonlinear friction states and disturbances, and has the advantages of high control precision, good stability and strong robustness.

Research on the Realistic Manifestation of Cyber Terrorismand Its Governance Path

Zhou Darui,Qing Cao 아시아사회과학학회 2022 Jornal of Asia Social Science Vol.6 No.1

At present, the field of network information has become a new battlefield of global anti-terrorism. Cyber terrorism has the characteristics of low cost, covert behavior and wide radiation of criminal consequences, which makes the antiterrorism work more difficult. Counter-terrorism work is faced with pain points such as lack of implementation of overall national security concept, anomie of legal system regulation, poor information sharing mechanism, disorder of international cooperation against terrorism and so on. Functional departments should practice the overall national security concept, improve the anti-terrorism system, promote anti-terrorism intelligence sharing, strengthen international anti-terrorism cooperation, and take multiple measures to eradicate the network soil where terrorism breeds, so as to achieve effective governance of network anti-terrorism.