• International Journal of Automotive Technology
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• 제8권3호
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• pp.375-382
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• 2007

The multi-driver off-road vehicle drive-line consists of many components, with close connections among them. In order to design and analyze the drive-line efficiently, a modular methodology should be taken. The aim of a modular approach to the modeling of complex systems is to support behavior analysis and simulation in an iterative and thus complex engineering process, by using encapsulated submodels of components and of their interfaces. Multi-driver off-road vehicles are comparatively complicated. The driving-line is an important core part to the vehicle, it has a significant contribution to the performance. Multi-driver off-road vehicles have complex driving-lines, so performance is heavily dependent on the driving-line. A typical off-road vehicle's driving-line system consists of a torque converter, transmission, transfer case and driving-axles, which transfers the power generated by the engine and distributes it effectively to the driving wheels according to the road condition. According to its main function, this paper proposes a modularized approach for design and evaluation of the vehicle's driving-line. It can be used to effectively estimate the performance of the driving-line during the concept design stage. Through an appropriate analysis and assessment method, an optimal design can be reached. This method has been applied to practical vehicle design, it can improve the design efficiency and is convenient to assess and validate the performance of a vehicle, especially of multi-driver off-road vehicles.

• 재활치료과학
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• 제9권1호
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• pp.45-55
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• 2020

목적 : 본 연구의 목적은 국내에 거주하는 뇌졸중 환자를 대상으로 시지각 능력이 운전수행에 미치는 영향을 알아보고 운전수행능력 향상을 위한 시지각 훈련의 중요성을 제시하고자 하였다. 연구 방법 : 2014년 10월부터 11월까지 서울시 소재 병원에 입원중인 뇌졸중 환자 19명을 대상으로 MVPT(Motor-free Visual Perception Test), TMT A&B(Trail Making Test A & B), UFOV(Useful Field Of View test)를 사용하여 시지각능력 검사를 실시하였으며, 가상현실 운전시뮬레이터를 이용하여 운전수행능력을 검사하였다. 결과 : 뇌졸중 환자의 운전수행은 다양한 시지각 능력 평가도구와 관련성이 있었으며, UFOV 하위검사 2, TMT B, MVPT에서 가장 높은 상관관계가 나타났다. 또한, 시지각 능력 평가결과는 운전시뮬레이터 평가결과(합격/불합격)를 민감도 100.0%, 특이도 80.0%, 정확도 89.5%로 판별할 수 있었다. 결론 : 뇌졸중 환자의 운전수행에 있어 시지각 능력이 운전수행능력과 매우 높은 관련성이 있는 것으로 나타났다. 본 연구를 통해 운전 재활 분야에서 시지각 능력과 관련된 운전재활 및 운전수행능력 평가를 시행하는데 유용하게 사용될 것으로 기대한다.

• 대한의용생체공학회:의공학회지
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• 제38권1호
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• pp.32-42
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• 2017

The aim of this study was to evaluate driving performance of Healthy and disabled groups (with or without driver's license) to control steering wheel by using steering assistive devices in the driving simulator. The persons with partial loss of use of all four limbs have problems in operation of the motor vehicle because of functional loss to operate steering wheel. Therefore, if steering assistive devices for grasping the steering wheel are used to control the vehicle on the road in persons with disabilities, the disabled persons can improve mobility in their community life by driving a motor vehicle safely. Ten healthy subjects (with or w/o driver's license) and ten subjects with physical disabilities (with or w/o driver's license) were involved in this study to evaluate driving performance to operate steering wheel by using four types of steering assistive devices (Single-pin, V-grip, Palm-grip, Tri-pin) in driving simulator. STISim Drive 3 software was used to test the steering performance in four scenarios: straight road at low and high speed of vehicle (40 km/h and 80 km/h), curved road at low and high speed of vehicle (40 km/h and 80 km/h). This study used two-way ANOVA in order to compare the effects of two factors (type of steering assistive device and subject group) in the three dependent variables of driving performance (the lateral position of vehicle, standard deviation of lateral position representing the variation of the left and right movement of the vehicle and the number of line crossing). The mean values of the three dependent variables (lateral position, standard deviation of lateral position, the number of line crossing) of steering performance were statistically significantly smaller for the healthy or disabled groups with driver's license than the other groups without driver's license on the curved road at high speed of vehicle compared to low speed of vehicle.

• 대한통합의학회지
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• 제8권2호
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• pp.89-95
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• 2020

Purpose : This study aims to evaluate the correlation of cognitive function, activities of daily living (ADL), and driving performance in stroke hemiplegic patients residing in Korea. Methods : Subjects of the study were 18 stroke hemiplegic patients admitted to hospitals situated in Seoul. A clock drawing test (CDT), a modified Barthel index (MBI), and a virtual reality driving simulator (Eca faros-driving simulator) were used to examine their cognitive function, their ADL ability, and their driving skills, respectively. Results : Driving skills of stroke hemiplegic patients were shown to be associated with the CDT evaluation tool (r=-.777) (p<.001), but they were found to have any correlation with MBI (r=-.022) (p>.05). Additionally, an individual's CDT showed that the driving simulator evaluation result (pass/fail) could be discriminated with a sensitivity of 100.0 %, a specificity of 40.0 %, and an accuracy of 66.7 %. The result confirmed that the CDT is a useful evaluation tool for screening driving ability in people with stroke. But the MBI did not show any significant results (sensitivity of 62.5 %, specificity of 40.0 %, and predicted the results of the simulator with 50.0 % of accuracy) (p>.05). Conclusion : This study shows that cognitive function influences the driving performance in people with stroke. Driving skills of stroke hemiplegic patients are seen to be highly related to CDT. In the field of driving rehabilitation, these findings could be useful for evaluating driving skills relating to CDT. Furthermore, the study results will set a guideline for domestic occupational therapists to use the evaluation tool for assessing driving abilities in people with stroke.

• 조명전기설비학회논문지
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• 제22권11호
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• pp.9-14
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• 2008

This paper presents the performance analysis of 10[Gb/s] optical duobinary transmitters with the non-ideal Mach-Zehnder modulator which does not have exactly 50/50 splitting/combining ratios by computer simulations. For driving voltage ratios(=driving voltage/switching voltage) with smaller than 100[%], the transmission performance has been greatly affected by extension of LPF bandwidths. Nevertheless, the performance has been degraded when the driving voltage ratio is 100[%]. The smaller driving voltage ratios has, the more sensitivity improves by extension of LPF bandwidths under the asymmetry condition. But the driving voltage ratio with 80[%] has better bit error rate(BER) than those with 50[%] and 25[%].

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.614-617
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• 1995

The unbalance heavy-load elevation driving systems are composed of rotating link-mechanism and hydraulic cylinder which actuates elevation and compensates the static unbalance moment of supporting mechanism. Control and compensation of gun driving is very difficult because these mechanism imply highly nonlinearities due to hydraulic fluid characteristics and mechanical rotation of link-mechanism. In this study, through the analysis of manufactured link-mechanism, the optimal link-mechanism design of the elevating system is suggested. Also to estimate the control performance of the unbalance heavy-load elevation servo-control driving system, modeling and simulation of the system are carried out. To prove the reliability of performance estimation program,simulation results are compared with the experimental results. Both results are similar, therefore this program will be helpful to study the control performance improvement of the system.

• ETRI Journal
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• 제45권1호
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• pp.75-92
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• 2023

Level 3 autonomous vehicles require conditional autonomous driving in which autonomous and manual driving are alternately performed; whether the driver can resume manual driving within a limited time should be examined. This study investigates whether the demographics and subjective driving tendencies of drivers affect the take-over performance. We measured and analyzed the reengagement and stabilization time after a take-over request from the autonomous driving system to manual driving using a vehicle simulator that supports the driver's take-over mechanism. We discovered that the driver's reengagement and stabilization time correlated with the speeding and wild driving tendency as well as driving workload questionnaires. To verify the efficiency of subjective questionnaire information, we tested whether the driver with slow or fast reengagement and stabilization time can be detected based on machine learning techniques and obtained results. We expect to apply these results to training programs for autonomous vehicles' users and personalized human-vehicle interfaces for future autonomous vehicles.

• 한국자동차공학회논문집
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• 제7권6호
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• pp.222-230
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• 1999

A fixed type driving simulator is constructed with a car body, beam projector, operation software , driving scenario, and audio equipments. With the simulator, the cognitive effects of fatigue due to two hour continuous driving of a straight road is investigated . The effects of alcohol on driving performance is also studied. The braking operation and lane keeping performance due to fatigue and alcohol are investigated. Changes of vehicle motion due to these effects are verified by computer simulation.

• 동력기계공학회지
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• 제6권2호
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• pp.73-81
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• 2002

In this study, electronically controlled automatic transmission adopted on a subcompact model in the market was modelled, and the driving performances of the transmission were simulated with the models. Kinetic and dynamic models of working components are established. The driving simulation program is developed with those models, and the various driving conditions are analyzed. With the results, the dynamic behaviour of the engine and the automatic transmission is easily understood. Especially, the transient performances of torque converter and clutches are deeply analyzed. Skipping the vehicle road test by using this analyzing tool, we can expect the cost down and the reduction of the development period of automatic transmission.

• 한국자동차공학회논문집
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• 제10권1호
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• pp.234-243
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• 2002

When a vehicle is operated over sort terrain, torque(or soil thrust) applied to driving wheel brings about shear displacement far soil due to compression and shear failure of soil under tire. This shear displacement give rise to slip and a additional sinkage due to slip. This additional sinkage is usually referred to as slip-sinkage. The slip-sinkage is affected by soil conditions and inflation pressure of tire. This slip-sinkage influence tractive performance on driving wheel . We conducted the experimental study far investigating the effect of slip on sinkage and tractive performance of driving wheel, such as motion resistance, thrust and drawbar pull. The experiment was carried out over three different soil conditions(soft, hard and very hard soil) far a tire with three levels of inflation pressure(120kPa, 240kPa and 360kPa). The results of this study show qualitatively slipsinkage characteristics and slip-tractive performance relationships of driving wheel with soil conditions and inflation pressure of tire.