• Title, Summary, Keyword: Steer

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IMPROVEMENT OF DRIFT RUNNING PERFORMANCE BY STEERING SYSTEM WHICH ADDS DIFFERENTIATION STEER ASSISTANCE

  • NOZAKI H.
    • International Journal of Automotive Technology
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    • v.6 no.6
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    • pp.615-623
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    • 2005
  • In this research, an effective technique was examined to improve the drift running performance. Concretely, the driver model by which the counter steer was done was assumed to the model by which the vehicle body slip angle (and the vehicle body slip angle velocity) was feed back. Next, the effectiveness of the system which added the assist steer angle corresponding to the steering wheel angle velocity to a front wheel steer angle was clarified as a drift running performance improvement technique of the vehicle. As a result, because the phase advances when the differentiation steer assistance is added, it has been understood to be able to cover the delay of the counter steer when the drift running. Therefore, it has been understood that the drift control does considerably easily. Moreover, it has been understood that the differentiation steer assistance acts effectively at the drift cornering by which the drift angle is maintained in cornering and the severe lane change with a drift at a situation. That is, it was understood to be able to settle to the drift angle of the aim quickly at the time of the drift cornering because the delay of the control steer angle of the counter steer was improved. Moreover, it was understood for the transient overshoot of the vehicle tracks to be able to decrease, and to return to the state of stability quickly at the severe lane change.

Effect of Zeranol Injection on Dry Matter and Nutrient Intake Requirements at Growth Stages of Holsein Steer (Zeranol 투여가 홀스타인 거세우의 성장 단계별 건물 및 양분 섭취량에 미치는 영향)

  • 김현섭;권응기;윤상기;신종서;홍병주
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.17 no.4
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    • pp.399-406
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    • 1997
  • This research was carried out to investigate the effect of zeranol injection on dry matter(DM) and nutrient intake requirement by growth stage of early castrated bull with 3 treatments(bul1, steer, steer+zeranol) with 28 Holstein bull at National Livestock Research Institute. The main results were as follows: DM intake at growing and fatting stage was the highest in steer groups, that the highest in bull groups at finishing stage and overall mean DM intake was 5% lower at steer+zeranol groups compared to bull and steer, respectively. Net energy intake at finishing stage was the highest as 35.49 Mcal at bull groups, while overall mean net energy intake was 101 - 109% of NRC requirement without significant difference. Concentrate intake to body weight was 1.68- 1.82, 1.91 -2.08 and 1.81 -2.05% at growing, fatting and finishing stage, respectively. Overall mean concentrate intake to body weight at steer groups was 1.94%, which is 1.8 and 1.81% higher compared to bull and steer+zeranol groups, respectively. Feed conversion ratio(DM) during overall period was the worst at steer groups as 9.321g, and also net energy conversion ratio was similar to DM conversion ratio.

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Optimization of front Bump Steer for Improving Vehicle Handling Performances (차량의 조종 안정성 향상을 위한 전륜 범프 스터어 최적화)

  • 서권희;이윤기;박래석;박상서;윤희석
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.2
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    • pp.80-88
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    • 2000
  • This paper presents a method to optimize the bump steer characteristics (the change of toe angle with vertical wheel travel) with respect to hard points in the double wishbone front suspension of the four-wheel-drive vehicle using the design of experiment, multibody dynamics simulation, and optimum design program. Front and rear suspensions are modeled as the interconnection of rigid bodies by kinematic joints and force elements using DADS. The design variables with respect to the kinematic characteristics are obtained through the experimental design sensitivity analysis. An object function is defined as the area of absolute differences between the desired and experimental toe angle. By the design of experiment and regression analysis, the regression model function of bump steer characteristics is extracted. The design variables that make the toe angle optimized are selected using the optimum design program DOT. The lane change simulations and tests of the full vehicle models are implemented to evaluate the improvement of vehicle handling performances by the optimization of front bump steer characteristics. The results of the lane change simulations show that the vehicle with optimized bump steer has the weaker understeer tendency than the vehicle with initial bump steer.

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Change of Concentration of Hormones and Metabolic Materials in Serum by Age in Hanwoo (한우 혈청에서 호르몬 및 대사물질 농도들의 연령에 따른 변화에 관한 연구)

  • 전기준;김종복;최재관;이창우;황정미;김형철;양부근;박춘근;나기준
    • Journal of Embryo Transfer
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    • v.18 no.3
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    • pp.215-225
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    • 2003
  • This study was carried out to investigate the change of blood compositions by age in Hanwoo, and a total of 866 of Hanwoo, which consisted with 638 of steer and 228 of bulls, were used to measure serum concentrations. A multiple regression equation was estimated with collection age and blood composition as independent and dependent variables, respectively. Complicated regression equations for blood compositions in steer and bulls were IGF-I(cubic), calcium (linear), and IP(linear). Linear and cubic equations were fitted to testosterone in steer and creatinine in bulls, respectively. A cubic equation in steer and linear equation in bulls were fitted to HDLC. Equations of quadratic in steer and cubic in bulls were fitted to concentration of triglyceride, globulin, and A/G ratio. BUN was fitted by equations of cubic in steer and quadratic in bulls. TP and albumin were fitted by equations of quadratic in steer and linear in bulls. A cubic regression equation did not explain the change of cortisol by age in steer and bulls. A cubic regression equation did explain the change of glucose by age in steer, but not in bulls. Higher R-square values (R-SQUARE>0.1) were estimated to IGF-1, albumin, creatinine, Inorganic phosphorous(IP) and HDLC in steer, and testosterone, IGF-I, TP, albumin, glucose, creatinine, IP, and HDLC in bulls for the fitted regression equations of blood compositions. Therefore, IGF-I, albumin, creatinine, IP, and HDLC were regarded as comparatively large variation by age in steer and bulls.

Control of smart actuators for networked steer-by-wire system (네트워크 기반 Steer-by-wire 시스템을 위한 지능형 엑츄에이터 제어)

  • Lee, Dong-Ik
    • Journal of Sensor Science and Technology
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    • v.15 no.6
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    • pp.425-432
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    • 2006
  • This paper presents a control algorithm for smart actuators that can be used in a 'steer-by-wire' system for next-generation intelligent automobiles. 'Steer-by-wire' is a network-based mechatronic steering system in which mechanical linkages and hydraulics are replaced by electric motors and a digital communication network. The algorithm is designed not only to achieve the capabilities of following the desired steering angles while minimizing the discrepancy between two steering wheels, but also to tolerate an actuator with faults. The proposed algorithm is based on a simple proportional control so that it can be implemented in real-time with a low-cost embedded microcontroller. The effectiveness of the control algorithm is examined using a hardware-in-the-loop simulator consisting of two DC motors and a CAN bus network.

A Robust Method of Fault Diagnosis for Steer-by-Wire System's Sensor (Steer-by-Wire 시스템의 감지기에 대한 강인한 이상진단기법)

  • Moon S.W.;Ji Y.K.;Huh K.S.;Cho D.I.;Park J.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1463-1467
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    • 2005
  • This paper proposes an analytical redundancy technique for fault diagnostics of the sensor in steer-by-wire system. We use incorporating vehicle dynamics modeling into the design of a diagnostic system for steer-by-wire system. The use of a model of vehicle dynamics improves the speed and accuracy of the diagnoses. The proposed fault diagnostics algorithm is based on parity-space methods to generate residuals. To reduce the effects of modeling uncertainty and dynamic transients, the residuals are subject to filtering. We construct diagnostic system consisting residual threshold for detection and isolator with using the directional residual vector.

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A Study on Integrated Control of AFS and ARS Using Fuzzy Logic Control Method (Fuzzy Logic 제어를 이용한 AFS와 ARS의 통합제어에 관한 연구)

  • Song, Jeonghoon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.1
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    • pp.65-70
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    • 2014
  • An Integrated Dynamics Control system with four wheel Steering (IDCS) is proposed and analysed in this study. It integrates and controls steer angle of front and rear wheel simultaneously to enhance lateral stability and steerability. An active front steer (AFS) system and an active rear steer (ARS) system are also developed to compare their performances. The systems are evaluated during brake maneuver and several road conditions are used to test the performances. The results showed that IDCS vehicle follows the reference yaw rate and reduces side slip angle very well. AFS and ARS vehicles track the reference yaw rate but they can not reduce side slip angle. On split-${\mu}$ road, IDCS controller forces the vehicle to go straight ahead but AFS and ARS vehicles show lateral deviation from centerline.

STEER Inverted File Structure for Dynamic Document Insertion/Deletion (문서의 동적 삽입 삭제를 위한 STEER 역파일 구조)

  • 김남일;박영찬;주종철
    • Proceedings of the Korean Information Science Society Conference
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    • pp.174-176
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    • 1998
  • 역파일 구조(inverted file structure)는 검색 속도가 빠르기 때문에 정보검색 시스템의 색인정보 하부 저장구조로 널리 이용되지만 문서의 동적 삭제는 어려운 형태이다. 본 논문에서는 기존역파일 구조에 문서마다 색인어의 포스팅 레코드를 기록한 목록을 유지함으로써 문서의 동적 삭제가 용이하고, 위치정보를 포스팅 레코드에서 분리하여 위치 검색이 효율적인 역파일 구조를 설계한다. 설계된 역파일 구조는 STEER(Structured Entity Element Retrieval) 정보검색 시스템에서 구현되었다.

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