Dongnam Kim

The Virtual Environment for Force-Feedback Experiment of Excavator Using a Novel Designed Haptic Device

ABSTRACT: This paper describes an approach force-feedback of excavator which is considered for tele-operation using a novel designed haptic device in virtual environment. This study has two main themes, the newly designed haptic device and force-feedback algorithm in virtual environment for excavator. The device can be controlled by human arm joint. Using the device, motion of boom, arm and bucket is controlled by operator’s elbow, wrist and metacarpophalangeal(MCP) joint. The motion of a novel haptic device is very similar to excavator. So, it is very intuitive and operator can control the device easily, even if they use it for the first time. It is a marked contrast between commercial haptics and this device. And then, 3D virtual environment is modeled for the force-feedback experiment using OpenGL program and 3D graphical simulations are extensively performed. The haptic offer force-feedback to operator exerted on each link of excavator during the performing various operation with DC motors. In this case, the force, which is forced by DC motor for feedback, is different as purpose of excavator and type of working. In order to increase the efficiency of operation and the protection of equipment, it is necessary to detect the reaction forces.

Design of Haptic Device for Excavator with Pressure Transmitter

The number of dismantling sites for buildings has been rapidly increased and these processes are very dangerous. So many research papers have been published addressing the development of a remote controller for the dismantling equipments. In this paper, a novel concept of applying haptic control is proposed for the remote control of excavator-like dismantling equipment. As a haptic device system, this controller is designed to improve the operability of the excavator. This paper also includes all the dynamic analysis of excavator to design the haptic device. Then, the hydraulic system of excavator which uses the proportional valve and pressure transmitter is also studied briefly. And parameter estimation of excavator is carried out with least square method. Last simulation result which is about the parameter estimation will be shown. And operator can control the real excavator intuitively with this new model of haptic device.

Remote control of excavator with designed haptic device

The number of dismantling sites for buildings has been rapidly increased and these processes are very dangerous. So many research papers have been published addressing the development of a remote controller for the dismantling equipments. In this paper, a novel concept of applying tele-operated haptic device is proposed for the remote control of an excavator-like dismantling equipment. As a haptic device, this controller is designed to improve the operability of the excavator. This paper also includes all the necessary kinematic analysis to design the haptic device. In order to explore the feasibility of the device, modeling of the haptic device is used to demonstrate its convenience. Then, the hydraulic system of excavator which uses the proportional valve system is also studied. Lastly, motion control simulations to the real excavator working at construction site are conducted. As a result, before manufacturing the real haptic device, 3D graphical model of haptic device is proposed to confirm the feasibility of the developed haptic device. And operator can control the real excavator intuitively with this new model of haptic device.

Development of the Gripping Control Algorithm for Wire-Suspended Object in Steel Construction

Robot system used in building construction sites can efficiently reduce construction time and increase safety by replacing human in dangerous operations. This paper describes the development of a robotic manipulator control algorithm which provides stable and efficient gripping of a pendulum-like object. The pendulum object mimics the construction materials hanging from tower crane, such as steel beam and column. The robot should be able to handle the heavy objects in order to be used in the building construction sites. This control algorithm requires dynamic modeling of the hanging object. To simplify the analysis, the dynamic modeling was limited to the 2 dimensional pendulum movements in x-y plane. In order to achieve the stable and efficient gripping, a shock isolator is designed using a pre-acting control.

Motion Control of Excavator with Tele-Operated System

The number of dismantling sites for buildings has been rapidly increased and these processes are very dangerous. So many research papers have been published addressing the development of a remote controller for the dismantling equipments. In this paper, a novel concept of applying tele-operated device is proposed for the remote control of excavator-like dismantling equipment. As a tele-operated system, this controller is designed to improve the operability of the excavator. This paper also includes all the necessary kinematic analysis to design the tele-operated system. In order to explore the feasibility of the device, modeling of the tele-operated system is used to demonstrate its convenience. Then, the hydraulic system of excavator which uses the proportional valve system is also studied. And basic motion control simulations to the real excavator working at construction site are conducted with designed tele-operated system. And operator can control the real excavator intuitively with this new model of tele-operated system.

Omni-Directional Robot for Pavement Sign Painting Operations

The current pavement sign marking operations are manually carried out, which are labor-intensive. This method requires blocking traffic for a long period of time resulting serious traffic jam. Also, the workers are exposed to possible injury and even death by passing traffic. This paper deals with the development of a robotic system for automating the pavement sign painting operations. The robotic system consists of gantry frame equipped with omni-directional wheels and paint spray system. The workspace of the gantry robot is extended to one-lane width with the omni-directional wheels that are attached to the corners of the gantry frame. This research also includes the development of font data structures that contain the shape information of pavement signs. The end-effector path is automatically generated with this font data through the procedures of scaling up/down and partitioning the corresponding signs depending on the workspace size. The robotic sign painting equipment and related control algorithms are built and tested with real painting experiments of various signs, which shows satisfactory results.

A study on gain scheduling of intelligent excavator

One of the most important factors in Intelligent Excavator is to locate the bucket quickly and accurately to the right position. To locate the bucket accurately, the Arm and the hydraulic cylinder of the boom should be exactly controlled. But as voltage and the force that should be controlled can be different by the positioning of the excavator, exact controlling is a difficult task. For more accurate control of position of bucket tip, we are going to apply gain scheduling algorithm. In this paper, we looked on how much the excavator could be controlled with gain scheduling algorithm.

Design of a haptic device for dismantling processes using excavator

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 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, its workspace is analyzed and the workspace mapping from the haptic 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 haptic device to the joint variable information of the backhoe is included in this paper. 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.