• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1190-1194
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• 2007

Since the dismantling processes of building are very dangerous, there have been many studies to develop a remote operating devices using joystick. In this paper, in order to improve the operability of the dismantling actuator that is usually an excavator, a novel concept of tele-operated haptic device is proposed. Operators who use this haptic device with additional environmental sensing devices can work safely away from the dangerous sites. First, based on the concept design of the haptic device, the workspace mapping from the haptic device to the excavator is explored. Second, the kinematics which deals with the conversion from the 3 dimensional position information of the haptic device to the joint variable information of the backhoe is included. Lastly, 3D graphical simulation of both haptic device and the backhoe will be shown. This new design of the haptic device can be easily manufactured and gives the workers very convenient and transparent remote control capability.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.4
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• pp.346-352
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• 2010

This paper presents an intuitive interface scheme for controlling a hydraulic backhoe, which is a piece of excavating equipment consisting of a digging bucket on the end of a two-part articulated arm, and typically mounted and rotated on the back of a tractor or front loader. The passive levers/joysticks for actuator operations of a hydraulic backhoe are replaced into electric joysticks with a robotic controller, which will generate the end-effecter command trajectories of the backhoe through joystick rate control in cylindrical coordinate. The developed backhoe with the hydraulic control system showed the maxim position error of 3 cm with intuitive coordinate operations, which would be helpful for conveniently performing various excavating tasks with natural and effective ways.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.95-102
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• 2008

Since the processes of dismantling are very dangerous, there have been many studies to develop remote operating devices using joystick. In this paper, in order to improve the operability of the dismantling equipment that is usually an excavator, a novel concept of tole-operated device is proposed. Operators who use this device with additional environmental sensing devices can work safely away from the dangerous sites. First, based on the concept design of the remote controller, its workspace is analyzed and the workspace mapping from the device to the excavator is explored. Second, after 7 steps of the excavating processes are defined, the kinematics which deals with the conversion from the 3 dimensional position information of the device to the joint variable information of the backhoe is included in this paper. Lastly, 3D graphical simulation of both remote controller and the backhoe will be shown. This new design of the remote control device tan be easily manufactured and gives the workers very convenient and transparent remote control capability.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.78-83
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• 2007

The paper focuses on the establishment of optimized bucket path planning and trajectory control designated for force-reflecting backhoe reacting to excavation environment, such as potential obstacles and ground characteristics. The developed path planning method can be used for precise bucket control, and more importantly for obstacle avoidance which is directly related to safety issues. The platform of this research was based on conventional papers regarding the kinematic model of excavator. Jacobian matrix was constructed to find optimal joint angles and rotation angles of bucket from position and orientation data of excavator. By applying Newton-Raphson method optimal joint angles and bucket orientation were derived simultaneously in the way of minimizing positional errors of excavator. The model presented in this paper was intended to function as a cornerstone to build complete and advanced path planning of excavator by implementing soil mechanics and further study of excavator dynamics together.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.495-496
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.29 no.12
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• pp.1304-1312
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• 2012

According to the successful development of hybrid vehicle, hybridization of construction equipments like excavator, wheel loader, and backhoe etc., is gaining increasing attention. However, hybridization of excavator and commercial vehicle is very different. Therefore a specialized energy management control algorithm for excavator should be developed. In this paper, hybridization of excavators is investigated and a new energy management control algorithm is proposed. Four control parameters, i.e., lower baseline, upper baseline, idling generation speed, and idling generation torque, are newly introduced and a new operating principle using those four control parameters is proposed. The use of Genetic Algorithm for the optimization of the four control parameters from the view point of minimization of fuel consumption for standard excavating operation is suggested. In order to verify the proposed algorithm, dedicated simulation program of hybrid excavator was developed. The proposed algorithm is applied to a specific hydraulic excavator and 20.7% improvement of fuel consumption is achieved.

• Journal of the Korea Institute of Building Construction
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• v.8 no.4
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• pp.71-77
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• 2008

Earthwork is very equipment-intensive task and researches related to automated excavation have been conducted. There is an issue to secure the safety for an automated excavating system. Therefore, this paper focuses on how to improve safety for semi- or fully-automated backhoe excavation. The primary objective of this research is to develop the core technology for automated object detection in excavation work. In order to satisfy the research objective, a diverse sensing technologies are investigated and analysed in terms of functions, durability, and reliability. The authors developed detecting algorithm for the objects using laser sensor and verified its performance by several tests. The results of this study would be the basis for developing the automated object detection system.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.179-187
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• 2020

This paper investigates the construction equipment accidents by time. Construction sites are unique with many different hazardous conditions which cause accidents. According to the Occupational Safety and Health Administration (OSHA), accidents related to construction equipment are one of the most leading causes of fatal injuries in the construction industry. While there have been many studies investigating the equipment-related accidents, few research studies provided in-depth analyses about the time that accidents frequently occurred. By using the OSHA accidents data collected between 1997 and 2012, this paper analyzed the accidents data by time, equipment type including excavator, backhoe, dozer, and crane, accident cause, and injury class. The analyses revealed that the time window with most accidents was between 13:00 and 13:59. In terms of the injury class, the time windows with the highest numbers of equipment accidents were between 13:00 and 13:59 and between 11:00 and 11:59 for fatality and hospitalization, respectively. For the accident causes, equipment operator's error was the highest number of accident causes. It is expected that findings from the analyses can be used to more strategically develop management plans and guidelines to prevent accidents related to construction equipment to practitioners.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.364-367
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• 2008

Earthwork is very equipment-intensive task and researches related to automated excavation have been conducted. There is an issue to secure the safety for an automated excavating system. Therefore, this paper focuses on how to improve safety for semi- or fully-automated backhoe excavation. The primary objective of this research is to develop object detection algorithm for automated safety system in excavation work. In order to satisfy the research objective, a diverse sensing technologies are investigated and analysed in terms of functions, durability, and reliability and verified its performance by several tests. The authors developed the objects detecting algorithm for user interface program using laser sensor. The results of this study would be the basis for developing the automated object detection system.