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Improvement of the steering feel of an electric power steering system by torque map modification 总被引:1,自引:0,他引:1
Man Hyung Lee Seung Ki Ha Ju Yong Choi Kang Sup Yoon 《Journal of Mechanical Science and Technology》2005,19(3):792-801
This paper discusses a de motor equipped electric power steering (EPS) system and demonstrates its advantages over a typical
hydraulic power steering (HPS) system The tire-road interaction torque at the steering tires is calculated using the 2 d o
f bicycle model, in other words by using a single-track model, which was verified with the J-turn test of a real vehicle Because
the detail parameters of a steering system are not easily acquired, a simple system is modeled here In previous EPS systems,
the assisting torque for the measured driving torque is developed as a boost curve similar to that of the HPS system To improve
steering stiffness and return-ability of the steering system, a third-order polynomial as a torque map is introduced and modified
within the preferred driving torques researched by Bertollini Using the torque map modification sufficiently improves the
EPS system 相似文献
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Kyoungcheol?Oh Donghyeon?Kim Talchol?Kim Chulsoo?Kim Hyunsoo?KimEmail author 《Journal of Mechanical Science and Technology》2004,18(1):30-36
In this paper, operation algorithms for a parallel HEV equipped with a relatively small motor are investigated. For the HEV,
the power assist and the equivalent fuel algorithms are proposed. In the power assist algorithm, an electric motor is used
to assist the engine which provides the primary power source. In the equivalent fuel algorithm, the electric energy stored
in the battery is considered to be an equivalent fuel, and an equivalent brake specific fuel consumption for the electric
energy is proposed. From the equivalent fuel algorithm, distribution of the engine power and the motor power is determined
to minimize the fuel consumption for a given battery state of charge (SOC) and a required vehicle power. It is found from
the simulation results that the fuel economy and the final battery SOC depend on the motor discharge energy and it is the
best way to charge the battery only by the regenerative braking, not by the engine to improve the overall fuel efficiency
of the HEV with the relatively small motor. 相似文献
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针对小推力深空探测器采用多次行星借力的飞行控制策略优化问题,文章提出了一种将推进段作为整体与滑行段进行打靶拼接的方法,最大限度地减少了优化设计时的待优化参数个数.首先,文章给出了小推力飞行轨道的间接优化设计模型和基于B平面理论的行星借力模型.随后,建立了给定开关机时序条件下的小推力借力飞行控制策略优化模型;最后,采用遗传算法和序列二次规划算法循环对该模型进行优化求解,并以地球–金星–地球–木星小推力飞行轨道控制策略优化设计为例进行仿真分析,仿真结果验证了优化模型的正确性和有效性,表明本文的研究方法可对小推力多次行星借力飞行的控制策略进行优化设计. 相似文献
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骆行 《中国制造业信息化》2004,33(10):114-116
分析了基于差动轮系机构的汽车电动助力转向系统工作原理及其对汽车中心操纵性能的影响,首先对差动轮系转向机构进行了静力学和运动学分析,然后建立了简化的动力学仿真模型。仿真的结果表明,基于差动轮系机构的电动助力转向系统能提高汽车中心操纵性能。 相似文献
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This paper describes the design concept of the human assistant robot I-PENTAR (Inverted PENdulum Type Assistant Robot) aiming
at the coexistence of safety and work capability and its mobile control strategy. I-PENTAR is a humanoid type robot which
consists of a body with a waist joint, arms designed for safety, and a wheeled inverted pendulum mobile platform. Although
the arms are designed low-power and lightweight for safety, it is able to perform tasks that require high power by utilizing
its self-weight, which is the feature of a wheeled inverted pendulum mobile platform. I-PENTAR is modeled as a three dimensional
robot; with controls of inclination angle, horizontal position, and steering angle to achieve high mobile capability. The
motion equation is derived considering the non-holonomic constraint of the two-wheeled mobile robot, and a state feedback
control method is applied for basic mobile controls wherein the control gain is calculated by the LQR method. Through several
experiments of balancing, linear running, and steering, it was confirmed that the robot could realize stable mobile motion
in a real environment by the proposed controller. 相似文献
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利用自己合成的3-氯-2-羟丙基三甲基氯化铵(简称CTA)阳离子淀粉,对其在造纸上的应用过程进行了较为详细的研究,取得了成功.合成的CTA阳离子淀粉做为造纸助剂应用到造纸上,成纸断裂长提高了0.171km,耐折度提高了6次,成纸灰份提高0.29%,单程留着率提高3.09%,其质量优于目前企业生产中使用的同类型阳离子淀粉,具有较大的推广使用价值. 相似文献
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《Ergonomics》2012,55(12):1597-1618
Although often suggested as a control measure to alleviate musculoskeletal stresses, the use of mechanical assistance devices (i.e. manipulators) in load transfers has not been extensively studied. Without data describing the biomechanical effects of such devices, justification for decisions regarding implementation of such tools is difficult. An experimental study of two types of mechanical manipulators (articulated arm and overhead hoist) was conducted to determine whether biomechanical stresses, and hence injury risk, would be alleviated. Short distance transfers of loads with moderate mass were performed both manually and with manipulator assistance under a variety of task conditions. Using analysis and output from new dynamic torso models, strength demands at the shoulders and low back, lumbar spine forces, and lumbar muscle antagonism were determined. Strength requirements decreased significantly at both the shoulders and low back when using either manipulator in comparison with similar transfers performed manually. Peak spine compression and anteriorposterior (a-p) shear forces were reduced by about 40% on average, and these reductions were shown to be primarily caused by decreases in hand forces and resultant spinal moments. Two metrics of muscular antagonism were defined, and analysis showed that torso muscle antagonism was largest overall when using the hoist. The results overall suggest that hoist-assisted transfers, although better in reducing spine compression forces, may impose relatively higher demands on coordination and/or stability at extreme heights or with torso twisting motions. The relatively higher strength requirements and spine compression associated with the articulated arm may be a result of the high inertia of the system. Potential benefits of practice and training are discussed, and conclusions regarding implementation of mechanical manipulators are given. 相似文献
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Demands for micro-machining on glass have been increasing in various industries due to the unique properties of glass, such as transparency or biocompatibility. However, micro-channel fabrication on glass with high precision has been challenging due to its brittle characteristics. This research presents the CO2 laser-assisted micro-milling process and investigates the machining characteristics experimentally. Micro-channels without cracks were fabricated using micro-end mill and CO2 laser irradiation as an assisting heat source. Compared to the process without laser heating in the same matching conditions, the average surface roughness was reduced by 96%, and cutting force was reduced by 28% and 66% for the feed and thrust direction, respectively. Continuous and sheared chips were observed with laser heating, indicating the process is in ductile-regime machining. Through the investigation of machining parameters, it was found that micro-channels with low average surface roughness can be achieved at the proper laser power when the workpiece is heated up to the strain point at tool position, at low feed rate, and at high axial depth of cut, as long as the tool withstands the cutting forces. Consequently, it can be concluded that it is possible to increase the material removal rate in micro-milling of borosilicate glass with high quality by using the CO2 laser, which was found to be an effective and suitable heating method. 相似文献