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Annals of occupational hygiene
HUMAN
RESPONSE
TO VIBRATION
619
ride criteria, such as IS0 spectra and absorbed power. An example involving an agricultural tractor is presented to illustrate the approach. Topics: Ride (in General); Mathematical Simulation (Vehicle Response). H. S. Bedi 1977 Royal Military College ofScience, Applied Mechanics Branch, Department of Mechanical Engineering, Shrivenham, Report No. 5MVTil. Evaluation of tracking controls for use in a vibration environment. (87 pages, 31 figures, 13 tables, 22 references) Author’s Abstract. Many of the tasks required of the crew of an armoured fighting vehicle (AFV) involve tracking in one form or another. The efficiency with which this can be performed is influenced by the nature of the tracking control and the response of the human operator to the vibration he experiences as a result of vehicle motion. A wide variety of tracking controls operated by different limbs of the body is found in the vehicle. As a number of different sensory and motor processes are known to contribute to the performance of a tracking task, each of which may be affected by vibration in different ways, it is likely that the controls will perform differently under vehicle motion. This project is concerned with the study of the performance of a typical range of tracking controls under simulated AFV ride conditions. The project involves the selection and manufacture of ten tracking controls, six of which are typical of those found in AFVs and four not so common, but with potential for use in future AFVs. Ten male volunteers, all with military background, were subjected to a series of specially designed zero order, continuous, compensatory tracking tasks under vertical random vibration in the laboratory. Their performance was measured in terms of the integrated absolute tracking errors under both control (static) and vibration conditions and standard statistical techniques used to analyse the results. While the force-cum-displacement controls investigated, viz. the thumb controls and miniature joysticks, are seen to generally perform well under control conditions. most of the larger force-cum-displacement controls investigated, viz. the steering wheel, steering levers, and the gun elevation and traverse controllers, are found to perform better under vibration. Degradation of performance under vibration is also found to be generally lower in the larger controls with the exception of the foot pedal. While the steering wheel appears to be least sensitive to vibration, the foot pedal, on the other hand is the most sensitive. The performance of the only isotonic control considered, the rotary knob, though fairly sensitive to vibration, is found to perform better than most of the force-cum-displacement controls under control and vibration conditions independently. Topics: Pecformance Effects (Psychomotor). T. I Hempstock and D. E. O’Connor 1978 Annals qf Occupational Hygiene 21. 57 67. Assessment of hand transmitted vibration. (11 pages, 8 figures, 2 tables, 12 references) Authors’ Abstract. A discussion of the difficulties associated with the measurement of hand transmitted vibration is given and methods of overcoming some of these difficulties are discussed. Recommended exposure limits for the prevention of Vibration induced White Finger (VWF) are reviewed. Some spectra associated with work processes known to cause VWF are presented and are compared with the proposed exposure limits. Some comments on the validity of these exposure limits are made in the light of their relationship with the spectra. Topics: Vibration Syndrome; Vibration Measurements (Hand-held Tools) ; Criteria and Limits. T. Matoba, H. Kusumoto, Y. Mizuki, H. Kuwahara, K. Inanga and M. Takamatsu 1977 Tohoku Journal qf Experimental Medicine 123, 5745. Clinical features and laboratory findings of vibration disease: a review of 300 cases. (9 pages, 5 figures, 2 tables, 16 references)
RESPONSE
TO VIBRATION
619
ride criteria, such as IS0 spectra and absorbed power. An example involving an agricultural tractor is presented to illustrate the approach. Topics: Ride (in General); Mathematical Simulation (Vehicle Response). H. S. Bedi 1977 Royal Military College ofScience, Applied Mechanics Branch, Department of Mechanical Engineering, Shrivenham, Report No. 5MVTil. Evaluation of tracking controls for use in a vibration environment. (87 pages, 31 figures, 13 tables, 22 references) Author’s Abstract. Many of the tasks required of the crew of an armoured fighting vehicle (AFV) involve tracking in one form or another. The efficiency with which this can be performed is influenced by the nature of the tracking control and the response of the human operator to the vibration he experiences as a result of vehicle motion. A wide variety of tracking controls operated by different limbs of the body is found in the vehicle. As a number of different sensory and motor processes are known to contribute to the performance of a tracking task, each of which may be affected by vibration in different ways, it is likely that the controls will perform differently under vehicle motion. This project is concerned with the study of the performance of a typical range of tracking controls under simulated AFV ride conditions. The project involves the selection and manufacture of ten tracking controls, six of which are typical of those found in AFVs and four not so common, but with potential for use in future AFVs. Ten male volunteers, all with military background, were subjected to a series of specially designed zero order, continuous, compensatory tracking tasks under vertical random vibration in the laboratory. Their performance was measured in terms of the integrated absolute tracking errors under both control (static) and vibration conditions and standard statistical techniques used to analyse the results. While the force-cum-displacement controls investigated, viz. the thumb controls and miniature joysticks, are seen to generally perform well under control conditions. most of the larger force-cum-displacement controls investigated, viz. the steering wheel, steering levers, and the gun elevation and traverse controllers, are found to perform better under vibration. Degradation of performance under vibration is also found to be generally lower in the larger controls with the exception of the foot pedal. While the steering wheel appears to be least sensitive to vibration, the foot pedal, on the other hand is the most sensitive. The performance of the only isotonic control considered, the rotary knob, though fairly sensitive to vibration, is found to perform better than most of the force-cum-displacement controls under control and vibration conditions independently. Topics: Pecformance Effects (Psychomotor). T. I Hempstock and D. E. O’Connor 1978 Annals qf Occupational Hygiene 21. 57 67. Assessment of hand transmitted vibration. (11 pages, 8 figures, 2 tables, 12 references) Authors’ Abstract. A discussion of the difficulties associated with the measurement of hand transmitted vibration is given and methods of overcoming some of these difficulties are discussed. Recommended exposure limits for the prevention of Vibration induced White Finger (VWF) are reviewed. Some spectra associated with work processes known to cause VWF are presented and are compared with the proposed exposure limits. Some comments on the validity of these exposure limits are made in the light of their relationship with the spectra. Topics: Vibration Syndrome; Vibration Measurements (Hand-held Tools) ; Criteria and Limits. T. Matoba, H. Kusumoto, Y. Mizuki, H. Kuwahara, K. Inanga and M. Takamatsu 1977 Tohoku Journal qf Experimental Medicine 123, 5745. Clinical features and laboratory findings of vibration disease: a review of 300 cases. (9 pages, 5 figures, 2 tables, 16 references)