Papers by Hidekazu Nishimura
Transactions of the Japan Society of Mechanical Engineers. C, 2012
This paper presents control system design for occupant lower extremity protection in the event of... more This paper presents control system design for occupant lower extremity protection in the event of a frontal car crash. A semi-active knee bolster is used to protect occupant lower extremities. The semi-active knee bolster varies the damping coefficient of the knee bolster. The control system design of the semi-active knee bolster is based on a design method of an active knee bolster. LQI (Linear Quadratic Integration) control with an initial value compensation input is applied. We obtain an optimal reference signal of the contact force between the knees and the instrument panel by considering characteristics of the semi-active actuator and the closed loop control system. The control system of the semi-active knee bolster follows the reference signal of the contact force. The protective control system with the semi-active knee bolster is effective for reducing the femur load, verified by carrying out simulations and experiments.
Nihon kikai gakkai ronbunshu, 2016
Thermal design of electronic products has become increasingly complicated with leakage current ch... more Thermal design of electronic products has become increasingly complicated with leakage current characteristics and their variation of semiconductors. This paper proposes an application of a thermal system model to a production system of electronic products. The thermal system model is developed for architecture design to determine design parameters of modules. The model is described with Systems Modeling Language (SysML) considering interactions among parameters of mechanical structure and electrical components that include semiconductors with temperature-dependent leakage current characteristics. In the system model, constraints of heat generation and heat transfer are described using equations and relation between equations and parameters are clarified in parametric diagram. The system model that is developed at the early stage of product design is used at the beginning of integration, such as receiving inspection. To prevent quality degradation by variation in component characteristics, semiconductor components such as processing units are screened with thermal simulation result before their implementation on Printed Wiring Board (PWB). The simulation result is being referred to temperatures that cause low-temperature burn injury. As a case study, a system model of portable product is developed and demonstrates thermal simulation to determine limitation in large variation in leakage current characteristics to satisfy product thermal quality. To improve yield ratio of the semiconductor components after screening, system models are developed for various products in which same processing units are installed. The system model can be applied for each product changing the design parameters and simulate to determine allowable range of component characteristics keeping the product quality. Implementing a component that causes more leakage effect into a product that has more allowable range, degradation of product quality can be avoid without losing the component yield ratio.
Transactions of the Japan Society of Mechanical Engineers. C, 2005
System design management and Synthesiology: Methodology to tackle the issues of modern society and to utilize the research results in the society
Synthesiology, 2019
Causes and countermeasures for various kinds of hydraulic system failures in construction machine... more Causes and countermeasures for various kinds of hydraulic system failures in construction machinery generated by biodegradable hydraulic oil (bio-oil) are discussed. Previous component analytical methods can prevent all kinds of failures except hydraulic system malfunction, which requires a holistic approach for analysis. Using the Systems Modeling Language (SysML), the cause of malfunctions can be understood, and the most effective countermeasure can be obtained. Integration of a component analysis method and a holistic analysis method for system development is proposed.
Transactions of the Society of Instrument and Control Engineers, 1996
The Proceedings of the Transportation and Logistics Conference, 2010
The Proceedings of the Symposium on the Motion and Vibration Control, 2011
The Proceedings of the Symposium on the Motion and Vibration Control, 2011
In this paper， we study the design ofan Anti − lock Brake System(ABS)using a dynamical model ofar... more In this paper， we study the design ofan Anti − lock Brake System(ABS)using a dynamical model ofarider ・ motorcycle system ， which considered the rider ， s dynarnic characteristics and vehicle ， s suspensions ． A Magic Formula tire model is us6d to describe the relationship between 血e slip rate and 廿】 e friction coe 価 cient ， We verify 廿 he effect of 廿ie designed ABS by using nonlinear simulations of front braking at the straight running on the Iow fhction coe 価 cient road su 血 ce ． In addition ， by adjusting the centU)l range of the slip rate as the design parameter of ABS ， the relationship betwcen the motorcycle ' s pitching and the braking dis 伽 ce is qua 皿 titatively analyzed ， The influence efsuspensions for the braking perfbrmance ofABS is also investigated ， κ 砂 〃 ' ords ： 肋 ' f一 め 0丸 Brlake Syste 〃1， 伽 励 0 の IlynamiCS， Rider−〃 btorcycle System ， lnfluence qズ Suspension ， Braking
The Proceedings of Mechanical Engineering Congress, Japan, 2012
Asimple dynamic model is usefUt to understand the essential dynamics of the occupant in car crash... more Asimple dynamic model is usefUt to understand the essential dynamics of the occupant in car crash and wm be ef 驚ctive to determine the properties of protection devices ． In this paper ， a reduced − order dynamic model is introduced based on human 行nite e ［ ement model having agc − specific characteristics such as bone stifヤ hess and tQlerance of the body． The reduced − order dynamic model consists oftwo masses and one rigid body ． The two masses correspond to the thorax and the lower body ， and the rigid body corresponds to thc upper body． The mass rcpresenting the thorax was connected
The Proceedings of Design & Systems Conference, 2015
The Proceedings of Design & Systems Conference, 2011
We have developed an immersive car driv 血g sim ロlatOr combining an immersive display K − Cave鋤 d ... more We have developed an immersive car driv 血g sim ロlatOr combining an immersive display K − Cave鋤 d a c 肛 c kpit sys ち 巳m 舳 as 舳 g for 一 feedback feature ． ersive c 町 齟 ng simula ω r enables a
The Proceedings of the Dynamics & Design Conference, 2012
Transactions of the JSME (in Japanese), 2015
Car navigation systems have recently become a popular assist system for automobiles. On the other... more Car navigation systems have recently become a popular assist system for automobiles. On the other hand, lack of dedicated motorcycle navigation system is still an issue. This is because currently provided navigation system utilizable for motorcycle has difficulties for riders to obtain information while driving. Recent research propose of using the headup display technology is considered to solve this issue. Although, topics about the amount of information to provide using the head-up display has not yet been discussed. Since providing too much information distracts driving behaviors, amount of information control is required to prevent inattentive driving behaviors. To evaluate the preferable amount of information, we conducted an experiment using the immersive motorcycle simulator integrated with a head-up display. The experiment measured motorcycle riders' viewpoint movements using the eye-mark recorder to observe the duration spent against the information provided using the head-up display. Through the experiment, we presented different length of Japanese syllabary characters (Hiragana) on the head-up display to 10 subjects. Experiments results indicate presenting 5 Japanese syllabary characters is the preferable amount of information to the motorcycle rider while driving. Applying information theories, we conclude that the preferable information transmission rate is approximately 16 bits per seconds.
The Proceedings of the Dynamics & Design Conference, 2012
Asimple dynamic model will be effective to determine the properties of protection devices because... more Asimple dynamic model will be effective to determine the properties of protection devices because it is useful to understand the essential dynamics of the occupant in car crash ． This paper describes an optimal restraint method in frontal c 肛 c 瓰 sh by using a 舳 ced − order dynamic皿 odel based on a human occupant finite element model hav 血 g age − speci 且c characteristics such as bone stiffness and tolerance of the body ， The restraint force is detemlined so as to minimize the maxlmum thoracic deflection ， which is one of the representing injury criteria in frontal car crash ， while the maximum thorax and pelvis displacements are restrai皿ed ． Simulation results clarify d】at the optimal restraint force is effective for reducing the maximum thoracic deflec 直on ．
The Proceedings of the Symposium on the Motion and Vibration Control, 2014
This paper presents design of a vehicle stability control system for a micro electric vehicle wit... more This paper presents design of a vehicle stability control system for a micro electric vehicle with four in-wheel motors by drivingforaking torque control eonsidering both vehicle handling and stability and energy consumption efficiency of in-wheel motors, To obtain a vehicle dynamical model for design of the vehicle stability control system, the subspace system identification method is applied using the inputioutput sigrials obtained from simulations of the fu11 vehicle rnodel, The fu11 vehicle model constructed by a simulation software based on the Modelica modeling language have been provided by the benckmark problem No,3 of the Society of Automotive Engineers of Japan and the Society of Instrument and Corrtrol Engineers. Afier analyzing frequency responses for the identified vehicle model, an H-infinity controller is designed to meet the requirement in terms ofvehicle handling and stability and energy consumption efficiency of in-wheel motors. By carrying out simulations under the crossing side wind test and the double lane change test for the vehicle model, it is demonstrated that the proposed control system satisfies the performance requirements,
The Proceedings of the Symposium on the Motion and Vibration Control, 2005
The Proceedings of the Symposium on the Motion and Vibration Control, 2009
Th 量 s paper presents i 【 ljury proteetion control of the occupant ' s 且 ower extremities in yehi... more Th 量 s paper presents i 【 ljury proteetion control of the occupant ' s 且 ower extremities in yehicle eollision with an active seat belt and an activc knee bolster ． The seat belt force for his or her pelvis is controlled by the active seat belt 、 The contact force between his or her knees and the instruJnent panel is controlled by the active knee bolster ． The centrol problem is formulatcd as an optimization problem and the control inputs are calculated to mi 舳 ize the rnaximum loadofhis orher femurs under the constraint ofthc maximum seat belt ferce． Numcrical simulations show that cooperative control of the active seat belt and thc active knee bolster reduces the maximum load of the femurs and the maximum seat belt force at the sarne time．
The Proceedings of Design & Systems Conference, 2014
In this papeら we discuss about the amount of navigatioll infbrmation to provide to the driver usi... more In this papeら we discuss about the amount of navigatioll infbrmation to provide to the driver using the head− up display car navigation fbr motorcycle ． From our previous research ， we oonfirmed presenting symbolic infbmlation like 狙 ows can navigate fbr a speci丘c crossroad ． It is clear dlat only provid 血 g one arrow of inforrnation is not enough to actUally navigate the motorcycle driver ． To provide enough geographical information ， usages of letters are necessary ． Although ， we need to consider not to provide too much information ， since we do not wisk the (iriver taking too much time looking at the provided information rather tha l looking at 丗 e road or 丗 e trafiic environment ． To confirm 丗 e proper information amount ， we conduCted a motorcycle simulator experiment in 血 e immersive CAVE environment using 丗 e head − up display ． T 肚e s 呵 ect was provided in 恥 ation in Japanese H かα go η α while (iriving the motorcycle simulator in a vir帆 Lal test course ． We used an eye mark recorder to measure the subject ， s viewpohlt to caloulate the duration spent fbr the presented inforrnation ． From the experiment ， we conclude that the preferable amo
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Papers by Hidekazu Nishimura