Stadiometer Measurements of Driver'S Spinal Response to Steering Force and Vibration

2000 ◽  
Vol 44 (30) ◽  
pp. 5-485-5-488
Author(s):  
Christine M. Haslegrave ◽  
Myles A. Mellor

The effects on spinal loading of two aspects of the driving task - force exertion while steering and exposure to 4 Hz 1ms−2 peak vertical seat vibration - were investigated with a group of six male subjects seated in a driving simulator. In addition, the effect of the combination of the two aspects was tested. Spinal shrinkage was measured with a precision seated stadiometer over a 40 minute period. Analysis of variance showed that both steering actions and vibration had a significant effect on spinal loading (p<0.05 and p<0.025 respectively), even though the steering torque (5Nm) was moderate. The response was significantly greater in all three experimental conditions than in static sitting (in the same posture). There appeared to be a tendency for the mean spinal shrinkage to increase from 6.0 mm when steering to 7.1mm under vibration and 8.7mm when steering and vibration were combined, but the only difference which was statistical significant was that between the combined condition and steering alone (t test, p<0.01).

Author(s):  
Zhuofan Liu ◽  
Wei Yuan ◽  
Yong Ma

The distribution of drivers’ visual attention prior to diverting focus from the driving task is critical for safety. The object of this study is to investigate drivers’ attention strategy before they occlude their vision for different durations under different driving scenarios. A total of 3 (scenarios) × 3 (durations) within-subjects design was applied. Twenty-three participants completed three durations of occlusion (0, 1, and 2 s) test drive in a motion-based driving simulator under three scenarios (urban, rural, motorway). Drivers’ occlusion behaviour, driving behaviour, and visual behaviour in 6 s before occlusion was analyzed and compared. The results showed that drivers tended to slow down and increased their attention on driving task to keep safety in occlusion 2 s condition. The distribution of attention differed among different driving scenarios and occlusion durations. More attention was directed to Forward position and Speedometer in occlusion conditions, and a strong shift in attention from Forward position to Road users and Speedometer was found in occlusion 2 s condition. Road users was glanced more frequently in urban road with a higher percentage of attention transitions from Forward position to Road users. While gaze switching to Speedometer with a higher intensity was found on motorway. It suggests that drivers could adapt their visual attention to driving demand and anticipate the development of upcoming situations by sampling enough driving-related information before eyes-off-road. Moreover, the adaptation and anticipation are in accordance with driving situation and expected eyes-off-road duration. Better knowledge about attentional strategies before attention away from road contributes to more efficient and safe interaction with additional tasks.


Author(s):  
R. Wade Allen ◽  
Zareh Parseghian ◽  
Anthony C. Stein

There is a large body of research that documents the impairing effect of alcohol on driving behavior and performance. Some of the most significant alcohol influence seems to occur in divided attention situations when the driver must simultaneously attend to several aspects of the driving task. This paper describes a driving simulator study of the effect of a low alcohol dose, .055 BAC (blood alcohol concentration %/wt), on divided attention performance. The simulation was mechanized on a PC and presented visual and auditory feedback in a truck cab surround. Subjects were required to control speed and steering on a rural two lane road while attending to a peripheral secondary task. The subject population was composed of 33 heavy equipment operators who were tested during both placebo and drinking sessions. Multivariate Analysis of Variance showed a significant and practical alcohol effect on a range of variables in the divided attention driving task.


Author(s):  
Patrick Siebert ◽  
Mustapha Mouloua ◽  
Kendra Burns ◽  
Jennifer Marino ◽  
Lora Scagliola ◽  
...  

This study used both cellular phones and analogue radio to measure driver distraction and workload in a low fidelity driving simulator. Thirty-four participants performed a simulated driving task while using either a cell phone or a radio in conjunction with a secondary task assessing their spare attentional capacity. The results showed that more lane deviations were made during the cell phone and radio tuning use than both of the pre-allocation and Post-allocation phases. The secondary task errors were also higher during both the cell phone and radio tuning allocation phase than the pre-allocation and post-allocation phases. These findings indicate the greater workload load levels associated with the use of telemetric devices. These findings have major implications for driver safety and telemetric systems design.


2001 ◽  
Author(s):  
Masao Nagai ◽  
Hidehisa Yoshida ◽  
Kiyotaka Shitamitsu ◽  
Hiroshi Mouri

Abstract Although the vast majority of lane-tracking control methods rely on the steering wheel angle as the control input, a few studies have treated methods using the steering torque as the input. When operating vehicles especially at high speed, drivers typically do not grip the steering wheel tightly to prevent the angle of the steering wheel from veering off course. This study proposes a new steering assist system for a driver not with the steering angle but the steering torque as the input and clarifies the characteristics and relative advantages of the two approaches. Then using a newly developed driving simulator, characteristics of human drivers and the lane-tracking system based on the steering torque control are investigated.


2005 ◽  
Vol 58 (1-2) ◽  
pp. 27-31
Author(s):  
Stanimir Stojiljkovic ◽  
Sanja Mazic ◽  
Dejan Nesic ◽  
Sasko Velkovski ◽  
Dusan Mitrovic

Introduction The purpose of this research was to compare changes in running velocity at ventilatory threshold with the veliocity at VO2max, before and after the eight-week exercise program. Material and methods 32 male subjects (age: 22.3? 2.5 years, height: 179.8? 7.6 cm, body mass: 76.8? 9.0 kg) performed a progressive test for ventilatory threshold (VT) measurement and VO2max on treadmill. After 8 weeks of endurance training (3 times per week, 30 to 70 min, in different zones in respect to the ventilatory threshold) the performed the same test. Results Running velocity at ventilatory threshold increased significantly (p=0.000I), between initial and final measurements (10.88?2.09, 12.94? 1.90 km/h, respectively): as well as at VO2max H4.63?1.86, 16.44?1.59 km/h, respectively). At the initial test, velocity at ventilatory threshold was 74.11% of VO2max. At the final test, velocity at ventilatory threshold was 78.43% of VO2max. Running velocity at ventilatory threshold has significantly increased at final test (p=0.001). Discussion Running velocity at ventilatory threshold has significantly increased after eight weeks of endurance training (p -0.001), when expressed in absolute values and percentage of velocity at vo2max. Conclusion Comparison between the initial and final test demonstrated a significant increase of observed variables, under experimental conditions: at final test running velocity has increased at ventilatory threshold, in respect to absolute values and expressed as percentage at VO2max. .


PEDIATRICS ◽  
1972 ◽  
Vol 49 (5) ◽  
pp. 702-708 ◽  
Author(s):  
C. Keith Conners

A number of myths have grown up regarding the behavioral effects and use of stimulant medications with children. The first is that there is a type of child uniquely responsive to stimulant compounds, namely, the hyperkinetic child. The second is that the hyperkinetic child is any child who is sufficiently overactive to be considered a menace by adults. The third is that the stimulant medications act primarily to reduce motor activity in a paradoxical "sedative" fashion; and finally, that the drugs do not influence cognitive and perceptual functioning in these children. I believe that these myths are due partly to the historical accident of the manner in which they were first studied, partly to the imprecision in diagnosis and terminology of classification of patients, and partly to the paucity of systematic data on sufficiently large samples under sufficiently varied experimental conditions. I would like to present the results of studies which bear on these issues, and try to draw some general conclusions regarding the present state of knowledge with regard to the use of the various psychostimulants. In this paper I will deal with dextroamphetamine, methylphenidate, and magnesium pemoline. I. METHYLPHENIDATE AND DEXTROAMPHETAMINE The children for this study were referred from schools, pediatricians, and social agencies for either academic or behavioral difficulties, or both. The subjects retained for the drug study comprised about ⅔ of the original referral sample. They were selected to fit the description of the child with "minimal brain dysfunction" as defined by the National Institute of Neurological Diseases and Stroke (NINDS) Task Force I report.


2021 ◽  
Author(s):  
Vishnu Radhakrishnan ◽  
Natasha Merat ◽  
Tyron Louw ◽  
Rafael Goncalves ◽  
Wei Lyu ◽  
...  

This driving simulator study, conducted as a part of Horizon2020-funded L3Pilot project, investigated how different car-following situations affected driver workload, within the context of vehicle automation. Electrocardiogram (ECG) and electrodermal activity (EDA)-based physiological metrics were used as objective indicators of workload, along with self-reported workload ratings. A total of 32 drivers were divided into two equal groups, based on whether they engaged in a non-driving related task (NDRT) during automation or monitored the drive. Drivers in both groups were exposed to two counterbalanced experimental drives, lasting ~18 minutes each, of Short (0.5 s) and Long (1.5 s) Time Headway conditions during automated car-following (ACF), which was followed by a takeover that happened with or without a lead vehicle. We observed that the workload on the driver due to the NDRT was significantly higher than both monitoring the drive during ACF and manual car-following (MCF). Furthermore, the results indicated that shorter THWs and the presence of a lead vehicle can significantly increase driver workload during takeover scenarios, potentially affecting the safety of the vehicle. This warrants further research into understanding safe time headway thresholds to be maintained by automated vehicles, without placing additional mental or attentional demands on the driver. To conclude, our results indicated that ECG and EDA signals are sensitive to variations in workload, and hence, warrants further investigation on the value of combining these two signals to assess driver workload in real-time, to help the system respond appropriately to the limitations of the driver and predict their performance in driving task if and when they have to resume manual control of the vehicle.


Author(s):  
Walter W. Wierwille ◽  
James C. Gutmann

In a previously reported experiment involving a moving base driving simulator with computer-generated display, secondary task measures of workload showed significant increases as a function of large changes in vehicle dynamics and disturbance levels. Because the secondary task measures appeared less sensitive than desired, driving performance measures recorded during the same experiment were later analyzed. Particular emphasis in examining the driving performance data was placed on (1) determining the degree of intrusion of the secondary task on the driving task as a function of the independent variables, and (2) on comparing the sensitivity of the primary and secondary task measures. The results showed the secondary task does intrude significantly upon the driving task performance at low workload levels, but that it does not significantly intrude at high workload levels. Also, when the four primary task measures were analyzed for sensitivity to the independent variables, new information was obtained indicating greater sensitivity than is obtained with the single secondary task measure. Steering ratio, for example, is found to affect performance at high disturbance levels—a result not obtained in examining the secondary task by itself. The merits of primary and secondary task performance analysis are discussed, and suggestions are made for future work.


Author(s):  
Liang-Kuang Chen ◽  
A. Galip Ulsoy

Human-in-the-loop driving simulator experiments are conducted to evaluate a proposed robust steering assist controller designed based upon driver uncertainty modeling. A nominal controller that is designed without consideration of driver model uncertainty is also tested for comparison. Two types of experiments are proposed. A long driving task with nominal configurations and a short driving task with initially large lateral position error. The data is analyzed using both time domain and frequency domain metrics. In the time domain, the standard deviation of lateral position error and percentage of road departure are used. In the frequency domain, the stability margins and crossover frequency are used. The driving simulator results indicate that statistically the designed robust controller shows improvements in the short driving experiments. The improvements in the long driving experiments are less evident due to driver adaptation. The non-robust nominal controller suffers from high gain and should be avoided. The benefits of considering driver model uncertainty in the design of vehicle steering assist controllers is, therefore, justified.


Author(s):  
Ganesh Pai Mangalore ◽  
Yalda Ebadi ◽  
Siby Samuel ◽  
Michael A. Knodler ◽  
Donald L. Fisher

The objective of the current study is to evaluate the use of virtual reality (VR) headsets to measure driving performance. This is desirable because they are several orders of magnitude less expensive than simulators and, if validated, could greatly extend the powers of simulation. Out of several possible measures of performance that could be considered for evaluating VR headsets, the current study specifically examines drivers’ latent hazard anticipation behavior both because it has been linked to crashes and because it has been shown to be significantly poorer in young drivers compared with their experienced counterparts in traditional driving simulators and in open road studies. In a between-subject design, 48 participants were equally and randomly assigned to one of four experimental conditions—two young driver cohorts (18–21 years) and two middle-aged driver cohorts (30–55 years) navigating either a fixed-based driving simulator or a VR headset-based simulator. All participants navigated six unique scenarios while their eyes were continually tracked. The proportion of latent hazards anticipated by participants which constituted the primary dependent measure, was found to be greater for middle-aged drivers than young drivers across both platforms. The difference in the magnitude of performance between the young and middle-aged drivers was similar across the two platforms. The study provides some justification for the use of VR headsets as a way of understanding drivers’ hazard anticipation behavior.


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