• 한국자동차공학회논문집
• /
• 제24권6호
• /
• pp.635-641
• /
• 2016

Regenerative braking performance of an electrically powered vehicle is closely related to driving distance per battery charge. An electric vehicle uses appropriate amounts of mechanical braking force and electromagnetic regenerative braking force to recover energy and increase driving efficiency. In particular, when it drives on a downhill road, energy recovery rate is maximized through regenerative braking during coasting based on the mass inertia of the vehicle. Since an electric two-wheeled vehicle covered in this paper is lighter than an electric four-wheeled vehicle, the improvement of its driving distance per battery charge through regenerative braking is different from an electric four-wheeled vehicle. This study compared the driving characteristics of an electric two-wheeled vehicle based on regenerative braking. Two driving test modes were simulated with a chassis dynamometer system. By analyzing the measurement of a chassis dynamometer, the driving characteristics of a two-wheel electric vehicle, such as driving efficiency, were analyzed. In addition, test results were reviewed to draw the limitations of conventional test methods for regenerative braking performance of an electric two-wheel vehicle.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2004년도 학술대회지
• /
• pp.117-122
• /
• 2004

In order to improve the fuel economy by design change of automatic transmission, various technologies such as increased shift stages, slip control of lock-up clutch and compact and low-weight design have been developed. And also many OEMs have developed their own ATFs as a part of these automatic transmissions. In this study. to investigate the effects of ATF characteristics on fuel economy, we got the worldwide OEM ATFs and made some reference fluids. And physical properties, frictional characteristics and fuel economy using dynamometer test for these fluids were evaluated. From the investigation, it was found that viscosities of ATFs are correlated with fuel economy in dynamometer test and reducing the viscosities made it possible to obtain fuel economy.

• 동력기계공학회지
• /
• 제15권6호
• /
• pp.16-21
• /
• 2011

Over the past years, many research works have been carried out to investigate the factors which govern the performance of diesel engine. The air pollutant emission from the diesel engine is still a significant environmental concern in many countries. In the present study, new system of smoke filtration of diesel engine is proposed. This new system is using vacuum equipment and filter for capture smoke. To verification new system experiments are performed at diesel vehicle and engine dynamometer. As a result it is founded that smoke is decreased of 67% at vehicle test and decrease of 45.2% at full load condition of engine dynamometer test.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.675-679
• /
• 2007

The control method of programmable dynamometer for overall test of machine is to load reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of moter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for moter torque of programmable dynamometer. Therefore, this kind of system could not perform dynamic and nonlinear load. In this paper, the control method using the load torque observer without a measure for torque transducer is proposed. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction moter. Therefore, the torque controller is not affected by a load torque disturbance.

• Tribology and Lubricants
• /
• 제21권3호
• /
• pp.142-148
• /
• 2005

In order to improve the fuel economy by design change of automatic transmission, various technologies such as increased shift stages, slip control of lock-up clutch and compact and low-weight design have been developed. And also many OEMs have developed their own ATFs as a part of these automatic transmissions. In this study, to investigate the effects of ATF characteristics on fuel economy, we got the worldwide OEM ATFs and made some reference fluids. And physical properties, frictional characteristics and fuel economy using dynamometer test for these fluids were evaluated. From the investigation, it was found that viscosities of ATFs are correlated with fuel economy in dynamometer test and reducing the viscosities made it possible to obtain fuel economy.

• Composites Research
• /
• 제16권4호
• /
• pp.22-28
• /
• 2003

본 연구는 자동차용 알루미늄 합금 디스크에 적용하기 위만 마찰재 제조에 관만 내용을 제시한 것이다. 최적 마찰재 조성을 확보하기 위하여 섬유, 결합재, 충진재, 마찰 성능 조정재 등으로 분류할 수 있는 각 원재료를 채택, 배합 설기에 의한 마찰재 시편을 제작하였으며 그 특성을 실제 차량 1/5 크기의 브레이크 다이나모미터를 이용하여 평가하였다. 마찰성능을 JASO C406 Pl에 준하여 실험만 결과 마찰계수가 0.35∼0.38. fade율이 18%였으며, 내 마모성은 JASO C427에 준하여 온도별 마모시험을 실시하였는데 시험 종료후 마찰재의 마로량이 1.6mm, 디스크 마모량이 0.08mm 수준인 우수한 배합 조성을 획득할 수 있었다. 시험 전$.$후의 마찰재와 알루미늄 합금 디스크의 표면상태는 주사전자현미경을 이용하여 관찰하였다.

• Journal of Biosystems Engineering
• /
• 제14권1호
• /
• pp.1-7
• /
• 1989

This study was carried out to develop a system and methodology to simulate the engine load variation occuring during agricultural field operations for a laboratory engine test. The system consisted of an electric dynamometer, an Apple II microcomputer, and a data acquisition and control system. Several pieces of instruments were utilized to measure various engine performance data. Both engine torque and engine speed were fully controlled by a computer program. The dynamic characteristics of the system were analyzed through a series of tests and the limitations on the load simulation test were presented. The results of the study are summarized as follows: 1. Engine speed and toque were controlled by a computer program. The use of a stepping motor and reduction gears enabled engine speed be controlled within 1 rpm. 2. The natural frequency of the dynamometer-engine system was found to be around 5 Hz, at which the load simulation would be impossible because of resonance. 3. For the harmonic inputs with the frequencies above the natural frequency, the signal attenuated too much and therefore the load simulation was impossible. 4. The step response of the system showed an overshoot of 24.5 percent and the settling time for 5 percent criterion was around 3 seconds. 5. When actual field test data are utilized for load simulation, a low-pass filter should be included to attenuate the frequency components around and above the natural frequency.

• Physical Therapy Rehabilitation Science
• /
• 제12권3호
• /
• pp.222-228
• /
• 2023

Objective: Training-related injuries and attrition put an additional burden on police and military institutions. Preventing and minimizing musculoskeletal injuries is the primary concern of the Abu Dhabi Police. Therefore, this study aimed to evaluate the correlation between functional movement screen, lower-limb strength, Y-balance test, grip strength and vertical jump and the incidence of musculoskeletal injuries among Abu Dhabi police recruits. Design: Observational analytical study. Methods: An observational study was conducted on 400 male police recruits of Abu Dhabi Police Academy. Physical performance was assessed before the 16-weeks basic police training. Spearman's correlation evaluated the correlation between the performance parameters and the outcome measures and logistic regression predicted the risk factors associated with musculoskeletal injuries. Results: 149 (34.4%) participants reported at least one injury during the basic police training. Comparison between injured and non-injured participants showed significant difference in mean right Y-balance, back-leg-chest dynamometer, and vertical jump (p=0.02, p=0.02, and p=0.04, respectively). Spearman's correlation showed a significant negative correlation between risk of injury and back-leg-chest dynamometer and right Y balance (ρ= -0.11, p=0.03). Logistic regression showed that back-leg-chest dynamometer and right Y balance were significant predictors of injury (p =.036 and p=0.037; Odds ratio=0.96; 95% CI (0.92, 0.99) and Odds ratio=0.99; 95% CI (0.98,0.99). Conclusions: Our findings suggest functional movement screen and grip strength may not independently predict injury rates, balance and lower-limb strength needs to be considered in injury prevention strategies to reduce musculoskeletal injuries.

• The Journal of Korean Physical Therapy
• /
• 제19권1호
• /
• pp.1-9
• /
• 2007

Purpose: Stenosing tenosynovitis is a stenosing condition of the sheath of the abductor pollicis longus and extensor pollicis brevis tendons at the radial styloid process. The purpose of this study was to investigate the effects of kinesio taping on the pain and grip power in patients with de Quervain's disease. Method: 20 female with de Quervain's disease was recruited. This procedure was performed with or without taping procedure. Pain levels were assessed using a visual analogue scale, and spherical and pinch grip powers were assessed using a dynamometer. Results: 1. Resting pain, Finkelstein test pain, and Tenderness using VAS scale was showed significantly reduced after taping application(p<0.01). 2. Spherical grip power using dynamometer was showed significantly increased after taping application(p<0.01). 3. Pinch grip power using dynamometer was showed significantly increased after taping application(p<0.01). Conclusion: So we thought that kinesio taping therapy had effects on the pain release and grip power increasing to the small or local muscle groups and joints.

• 산업기술연구
• /
• 제26권B호
• /
• pp.21-28
• /
• 2006

A diesel truck of 1 ton is re-powered by a gasoline engine and the fuelling system of gasoline engine modified to gasoline/CNG bi fuel system. The engine characteristics such as fuel economy and power are evaluated by driving rest, sloping test and dynamometer. The driving test prove the driving cost is saved by 55% and the maximum speed is raised by 13%, which is mainly due to the higher calorific value of CNG. The sloping test is done on the road of which slope is 15%. The truck shows the mean velocity of 88km/h, which means that a re-powered truck is working fine. The BHP are measured by dynamometer. The power and torque produced by a re-powered truck are reduced by 13% and 14% respectively from the power of gasoline engine. The BHP reduction is one of main problems which one has to solve in near future.