Response of human body to tractor vibrations and its minimisation by provision of relaxation suspensions to both wheels and seat at the plane of centre of gravity

Patil, Mothiram K.; Palanichamy, M. S.; Ghista, D. N.

doi:10.1007/bf02443126

Cited by 4 publications

(2 citation statements)

References 6 publications

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“…This category includes multiple-DOF linear models of a seated vehicle driver [35–37], shipboard sitting subject to underwater shock [38], seated pregnant women for examination of the vibration effect on the woman and fetus under both horizontal and vertical vibrations [39, 40], and seated wheelchair users [41]. Using the electrical analogy method for solution, it was found that horizontal vibrations affect body segments more than do vertical vibrations [40].…”

Section: Concept Of Mechanical Impedancementioning

confidence: 99%

“…Another example for a natural task is found in the design of torque-controlled manipulator (with torque disturbances) to identify the dynamics of the wrist joint, both under natural and neurologically impaired conditions, while the subject actively controls the joint angle [33]. Other activities were used for evaluating the joint impedance of the lower limbs: (a) simulation of single-leg standing using an open-loop model [4], (b) swaying motion in bi-pedal standing, used to feed a three-dimensional five-segment model with four joints by means of which an iterative estimation of the kinematics and dynamics of the system was conducted, opening the possibility of the estimation of the mechanical impedances in the joints of the lower extremity, power transfer through the joints, and the production of muscle forces [26], (c) hopping motions using a four-link lumped model [19], (d) jumping and running motion to establish the input force for one-dimensional multi-DOF impedances [9, 15, 35, 37, 81, 96], and (e) seated postures in oscillatory environments [35–43, 97]. Upper limb models were utilized for the simulation of various tasks, such as grasping during semi-oscillatory walking motion [14].…”

Section: Derivation Of Equations For Dynamic Modelmentioning

confidence: 99%

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Mechanical Impedance and Its Relations to Motor Control, Limb Dynamics, and Motion Biomechanics

Mizrahi

2015

J. Med. Biol. Eng.

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The concept of mechanical impedance represents the interactive relationship between deformation kinematics and the resulting dynamics in human joints or limbs. A major component of impedance, stiffness, is defined as the ratio between the force change to the displacement change and is strongly related to muscle activation. The set of impedance components, including effective mass, inertia, damping, and stiffness, is important in determining the performance of the many tasks assigned to the limbs and in counteracting undesired effects of applied loads and disturbances. Specifically for the upper limb, impedance enables controlling manual tasks and reaching motions. In the lower limb, impedance is responsible for the transmission and attenuation of impact forces in tasks of repulsive loadings. This review presents an updated account of the works on mechanical impedance and its relations with motor control, limb dynamics, and motion biomechanics. Basic questions related to the linearity and nonlinearity of impedance and to the factors that affect mechanical impedance are treated with relevance to upper and lower limb functions, joint performance, trunk stability, and seating under dynamic conditions. Methods for the derivation of mechanical impedance, both those for within the system and material–structural approaches, are reviewed. For system approaches, special attention is given to methods aimed at revealing the correct and sufficient degree of nonlinearity of impedance. This is particularly relevant in the design of spring-based artificial legs and robotic arms. Finally, due to the intricate relation between impedance and muscle activity, methods for the explicit expression of impedance of contractile tissue are reviewed.

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Section: Concept Of Mechanical Impedancementioning

confidence: 99%

Section: Derivation Of Equations For Dynamic Modelmentioning

confidence: 99%

Mechanical Impedance and Its Relations to Motor Control, Limb Dynamics, and Motion Biomechanics

Mizrahi

2015

J. Med. Biol. Eng.

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Single and joint actions of noise and sinusoidal whole body vibration on TTS2 values and low frequency upright posture sway in men

Manninen¹,

Ekblom²

1984

Int Arch Occup Environ Heath

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In the present study the changes in the TTS2 values and body upright posture sway were examined after exposure of subjects (n = 10) to stable broadband (white) noise (90 dB) alone, to sinusoidal vibration alone [directed vertically at the whole body (Z axis)], and to simultaneous exposure combinations of noise and vibrations of the same type. The frequency of the vibration was 5 Hz, but its acceleration was either 2.12 or 2.44 m/s2. There were six exposure combinations, and subsequently 60 tests were carried out in an exposure chamber. One test consisted of a control period of 30 min, of three consecutive exposure periods of 16 min each and of a recovery period of 15 min. After the three exposure combinations which included noise, half of the subjects were exposed to vibration during the recovery period. Apart from indicating an increase in the temporary hearing threshold, the results showed that simultaneous exposure to noise and vibration increases the instability of the body upright posture. The TTS2 values at the 4 and 6 kHz frequencies increased considerably more rapidly when the subjects were exposed simultaneously to noise and vibration than when exposed to noise alone. Without exception, the TTS2 values increased most during the first exposure period. It was noteworthy that exposure to vibration during the recovery period accelerated the recursion of the TTS2 values, especially in cases where the subjects had been exposed to noise alone. The variance of the body sway amplitudes and the standard deviation increased within the frequency range 0.063-2.000 Hz owing to noise alone and simultaneous noise and vibration. In the directions X and Y, within the frequency ranges 0.063-0.100 Hz and 0.100-0.600 Hz, the means of the maximum amplitudes of body sway increased especially in connection with those tests in which the subjects had been simultaneously exposed to noise and vibration.

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Vibration attenuation performance of suspension seats for off-road forestry vehicles

Boileau

Rakheja

1990

International Journal of Industrial Ergonomics

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Response of human body to tractor vibrations and its minimisation by provision of relaxation suspensions to both wheels and seat at the plane of centre of gravity

Cited by 4 publications

References 6 publications

Mechanical Impedance and Its Relations to Motor Control, Limb Dynamics, and Motion Biomechanics

Mechanical Impedance and Its Relations to Motor Control, Limb Dynamics, and Motion Biomechanics

Single and joint actions of noise and sinusoidal whole body vibration on TTS2 values and low frequency upright posture sway in men

Vibration attenuation performance of suspension seats for off-road forestry vehicles

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