• Journal of the Korean Society for Precision Engineering
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• v.29 no.1
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• pp.72-78
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• 2012

In this research an equilibrium point of a Wheeled Inverted Pendulum (WIP) running on an inclined road is derived and validated by some experiments. Generally, The WIP has stable and unstable equilibrium point. Only unstable equilibrium point is interested in the research. To keep the WIP on the unstable equilibrium point, the WIP is consistently controlled. A controller for the WIP needs a reference state for the equilibrium point. The reference state can be obtained by studying an equilibrium point of the WIP. This research is deriving dynamic equations of the WIP running on the inclined road and equilibrium of it based on statics. Several experiments are carried out to show the validation of the equilibrium point.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.245-250
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• 2003

Digital Elevation Model(DEM) is basic spatial information used in various GIS areas such as spatial analysis, 3D modeling, etc. In particular, DEM of road inclined plane is need for the plan, design, construction and maintenance of social infrastructures such as roads and bridges in construction technology, one of GIS application. However, generating DEM of road inclined plane with high accuracy is very difficult. Therefore, the purpose of this study is to propose how to generate road DEM with high accuracy through extracting road inclined plane automatically using Laser scanning data.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.617-623
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• 2010

In this research an LMI based mixed $H_2/H_{\infty}$ controller for a Wheeled Inverted Pendulum is designed and a numerical simulation of that is carried out. The Wheeled Inverted Pendulum is a kind of an inverted pendulum that has two equivalent points. To keep that the naturally unstable equivalent point, a controller should control the wheels persistently. Dynamic equations of the Wheeled Inverted Pendulum are derived with considering inclined road that is one of the representative road conditions. A Linear Matrix Inequality method is used to construct a controller that is able to stabilize the Wheeled Inverted Pendulum with considering the inclined road condition aggressively. Various numerical simulations show that the LMI based controller is doing well on not only flat road but also inclined road condition.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.69-74
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• 2012

In this research equations of motion of a Wheeled Inverted Pendulum (WIP) which is running on the inclined road and changing its center of gravity. Difference between a conventional cart inverted pendulum and the WIP is also considered. The WIP has small planar size so that it has been used as a mobile platform for several applications which require slender frame in order to travel on the narrow road. The WIP has almost the same unstable properties as conventional inverted pendulums have. There needs an aggressive control scheme for the WIP not to fall down. In order to design a high performance control scheme, equations of motion of the WIP, which is running under various environment and operating conditions, should be derived and considering its properties is necessary.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.3
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• pp.283-289
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• 2011

In this research a controller based on velocity estimator for a Wheeled Inverted Pendulum (WIP) is designed and various numerical simulation studies are carried out. The WIP has stable and unstable equivalent points. To Keep the unstable equilibrium point, a controller should control carefully the wheels persistently. There are angle, angular velocity, displacement, and velocity of the WIP for controller inputs. The velocity is obtained by differentiating the encoder signals from the motor and is subject to the resolution of the encoder. An improved velocity detection method is proposed based on low resolution encoder and velocity estimator. Various numerical simulations are carried out for showing the validation of the velocity estimator in case of the inclined road condition.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.14-19
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• 2012

On-line and real-time information of the longitudinal velocity is the essential factor for the Advanced Vehicle Control Systems such as ABS(Anti-lock Brake System), TCS(Traction Control System), ESC (Electronic Stability Control) etc. However, the longitudinal velocity cannot be easily measured or calculated during braking maneuvering. A new algorithm is presented for the estimation of the longitudinal velocity with the measurements of the vehicle longitudinal/lateral acceleration, steering angle and yaw rate. The algorithm is designed utilizing the Extended Kalman Filter based on the 3 degree of freedom vehicle model. In order to compensate for the biased sensor signal on the inclined road, the inclined angle is also estimated. The performance of the proposed estimation algorithm is evaluated in field tests.

• Geomechanics and Engineering
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• v.8 no.6
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• pp.801-810
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• 2015

The ultimate pullout capacity under inclined dynamic loading is an important measure of the destruction degree of vertical screw piles (anchors) under dynamic actions. Based on the static and dynamic tests on two kinds of model screw piles, the ultimate bearing capacity was researched considering different distance-width ratio of blade (D/W) and preloading ratio. The results compared well with other experimental data available in the literature. This research reveals that D/W might determine the failure model of the piles (anchors), for example D/W = 3.14 or 5; a critical dynamic-static loading ratio (DSLR) existed in the experiments. The critical DSLR was reached under the conditions of 40%~60% preloading (D/W = 3.14) or 20%~40% preloading (D/W = 5), respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.725-726
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• 2010

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.719-726
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• 2009

One of the alternative runoff management measures is on-site runoff mitigation, such as rainwater retention tank and infiltration facilities especially the latter that is possible to manage simultaneously runoff quality and quantity as a perspective of water-cycle. This study was conducted to develop a particle separator, inclined-pipe settling system, that could improve particle removal efficiency of road runoff as a pre-treatment device of stormwater infiltration. Solid particles larger than $100{\mu}m$ are separated by simple sedimentation; however, the significant amount of pollutants with a diameter less than $100{\mu}m$ remain in suspension. Without any treatment in that case of the runoff into infiltrate, groundwater would be deteriorated and also infiltration rate would be decreased by clogging. Therefore, we suggest optimal design parameters (inclined angle, pipe length, and surface loading rate) of inclined-pipe settling system which can be designed to effectively remove particles diameter smaller then $70{\mu}m$. Thus, the results showed TSS removal efficiency more than 80% with a particle diameter between $20{\mu}m$ and $70{\mu}m$, 100% above particle diameter $70{\mu}m$ for the inflow rate $0.018 m^3/m^2{\cdot}hr$ with pipe inclined at angle $15^{\circ}$.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.82-91
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• 2011

In this paper, a planar model for mechanics of a vehicle/pedestrian collision incorporating road gradient is derived to evaluate the pre-collision speed of vehicle. It takes into account a few physical variables and parameters of popular wrap and forward projection collisions, which include horizontal distance traveled between primary and secondary impacts with the vehicle, launch angle, center-of-gravity height at launch, distance from launch to rest, pedestrian-ground drag factor, the pre-collision vehicle speed and road gradient. The model including road gradient is derived analytically for reconstruction of pedestrian collision accidents, and evaluates the vehicle speed from the pedestrian throw distance. The model coefficients have physical interpretations and are determined through direct calculation. This work shows that the road gradient has a significant effect on the evaluation of the vehicle speed and must be considered in accident cases with inclined road. In additions, foreign/domestic empirical cases and multibody dynamic simulation results are used to construct a least-squares fitted model that has the same structure of the analytical one that provides an estimate of the vehicle speed based on the pedestrian throw distance and the band within which the vehicle speed would be expected to be in 95% of cases.