• Journal of Drive and Control
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• v.20 no.4
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• pp.27-34
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• 2023

Weeding in orchards is closely associated with productivity and quality. The customary weeding process is both labor-intensive and time-consuming. To solve the problems, there is need for automation of agricultural robots and machines in the agricultural field. On the other hand, orchards have complicated working areas due to narrow spaces between trees and amorphous terrain. Therefore, it is necessary to develop customized robot technology for unmanned weeding work within the department. This study developed a path generation and path control method for unmanned weeding according to the orchard environment. For this, the width of the weeding span, the number of operations, and the width of the weeding robot were used as input parameters for the orchard environment parameters. To generate a weeding path, a weeding robot was operated remotely to obtain GNSS-based location data along the superheated center line, and a driving performance test was performed based on the generated path. From the results of orchard field tests, the RMSE in weeding period sections was measured at 0.029 m, with a maximum error of 0.15 m. In the steering period within row and steering to the next row sections, the RMSE was 0.124 m, and 0.047 m, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.446-452
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• 2016

Recently, heat resistant super alloys (which are wear-resistant, corrosion-resistant, and heat-resistant), have been used as the basic structural material in offshore and petrochemical plants. On the other hand, making valves from very expensive, high heat-resistant alloys increases the production cost and decreases its market competitiveness. To solve these problems, the technique of overlaying only those that flow on the fluid has been used as an effective method. Nevertheless, because the former technique of overlaying the ball is performed manually, it takes too much time and perfect welding is difficult to perform. To solve this problem, this study developed a robot automation system that can make uniformly overlay welding of the ball for ball-valves. The system consists of a 6-axis welding robot with a welding torch and additional 2 axes for the rotation of positioner, the controller, and a robot path OLP (Off-Line Programming). The CAD drawing data was entered in the Off-line program to obtain the robot teaching point and drive source. Overlay welding paths were implemented using Matlab. Through an automated overlaying system that implemented the OLP, the productivity rose 2.58 times, as the amount of time required for work decreased from 88 hours to 41 hours.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.10
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• pp.833-838
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• 2016

This paper presents a performance evaluation of various feature-initialization algorithms for forward-viewing mono-camera based simultaneous localization and mapping (SLAM), specifically in indoor environments. For mono-camera based SLAM, the position of feature points cannot be known from a single view; therefore, it should be estimated from a feature initialization method using multiple viewpoint measurements. The accuracy of the feature initialization method directly affects the accuracy of the SLAM system. In this study, four different feature initialization algorithms are evaluated in simulations, including linear triangulation; depth parameterized, linear triangulation; weighted nearest point triangulation; and particle filter based depth estimation algorithms. In the simulation, the virtual feature positions are estimated when the virtual robot, containing a virtual forward-viewing mono-camera, moves forward. The results show that the linear triangulation method provides the best results in terms of feature-position estimation accuracy and computational speed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.153-158
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• 2000

This paper addresses an intelligent robot control system using an off-line programming to teach a precise assembly task of electronic components in a flexible way. The investigated task consists of three job: heat caulking test, soldering on a circuit board, and checking of soldering defects on the back cover of a camera. This study investigates the remodelling of the most complicated cell in terms of the accuracy and fault rate among the twelve cells in a camera back-cover assembly line. We have attempted to enhance back-cover assembly line. We have attempted to enhance soldering quality, to add task flexibility, to reduce failure rate, and to increase product reliability. This study modifies the cell structure, and improves the soldering condition. The developed all system implements the real-time control of assembly with vision data, and realized an easier task teaching on off-line programming.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.274-274
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• 2000

In the future, the convenient speech command system will become an widely-using interface in automation systems. But the previous research in speech recognition didn't give satisfactory recognition results for the practical realization in the noise environment. The purpose of this research is the development of a practical system, which reliably recognizes the speech command of the registered users, by complementing an existing research which used the image information with the speech signal. For the lip-reading feature extraction from a image, we used the DWT(Discrete Wavelet Transform), which reduces the size and gives useful characteristics of the original image. And to enhance the robustness to the environmental changes of speakers, we acquired the speech signal by stereo method. We designed an economic stand-alone system, which adopted a Bt829 and an AD1819B with a TMS320C31 DSP based add-on board.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.229-237
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• 2024

The logistics industry is converging with digital technology and growing into various logistics automation systems. However, inspection and loading/unloading, which are mainly performed in logistics work, depend on human resources, and the workforce is shrinking due to the decline in the productive population due to the low birth rate and aging. Although much research is being conducted on the development of automated logistics systems to solve these problems, there is a lack of research and development on load stacking stability, which has the potential to cause significant accidents. In this study, loading boxes with various sizes and positions of the center of gravity were set up, and a method for stacking that with high stability is presented. The size of the loading box is measured using a depth camera. The loading box's weight and center of gravity are measured and estimated by a developed device with four loadcells. The measurement error is measured through various repeated experiments and is corrected using the least squares method. The robot arm performs load stacking by determining the target position so that the centers of gravity of the loading boxes with unbalanced masses with a random sequence are transported in alignment. All processes were automated, and the results were verified by experimentally confirming load stacking stability.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.2
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• pp.128-134
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• 2019

In shipbuilding, accurate fabrication of curved hull plates is one of the most important steps, since the shape of ship hull, which is very critical in the overall performance of a ship, is a collection of such plates. The curved hull plates forming process requires a significant amount of time by skilled workers in shipbuilding. In general, the workers cause thermal distortion in the plate and forming initial shape using gas heat source. So shipbuilding companies need skilled workers who have long experience. To solve the problem, a lot of researchers tried to develop automation system for curved hull plates. In this paper, we propose automatic heating system with gantry robot, high frequency induction heater to replace the gas heat source and automatic measurement system. We apply the system to forming concave type plate that is actually used in ship manufacturing. In addition, a system was developed to automatically generate heating information, such as the heating location and the heating speed, for actual heating process. Then the system was applied to the actual heating material. It is shown that the proposed triangle heating pattern makes desired concave shape successfully. The induction heating system showed that it can be used for automation system of curved hull plates forming process replacing gas heat source.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.649-652
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• 2005

The camera cellular phone has a large portion of cellular phone market in recent year. The variety of a customer demand makes a fast model change and the spatial resolution is changed from VGA to multi-mega pixel. The 1.3 mega pixel (MP) camera cellular phone was first released into the Korean market in October 2003. The major cellular phone companies released a 2MP camera cellular phone that supports zoom function and a 2MP camera cellular phone is settled down with the Korea cellular phone market. It makes a keen competition in price and demands automation for phone camera module. There is an increasing requirement for the automatic assembly to correspond to a fast model change. The hard automation techniques that rely on dedicated manufacturing system are too inflexible to meet this requirement. Therefore in this study, this system is designed with the flexibility concept in order to cope with phone camera module change. The system has a same platform that has X-Y-Z motion or X-Z motion with ${\mu}m$order accuracy. It has a special gripper according to the type of a component to be put together. If the camera model changes, the gripper may be updated to fit for the camera module. The controller of this system acquires the data sets that have the information about the assembly part by the tray. This information is obtained ahead of an inspection step. The controller excludes an inferior part to be assembled by using this information to diminish the inferior goods. The assembly jig used in this system has a function of self adjustment that reduces the tact time and also diminish the inferior goods. Finally, the intelligent assembly system for phone camera module will be designed to get a flexibility to meet model change and a high productivity with a high reliability.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.2
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• pp.165-173
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• 2012

Nationally, flatfish vaccination has been performed manually, and is a laborious and time-consuming procedure with low accuracy. The handling requirement also makes it prone to contamination. With a view to eliminating these drawbacks, we designed an automatic vaccine system in which the injection is delivered by a Cartesian coordinate robot guided by a vision system. The automatic vaccine injection system is driven by an injection site location algorithm that uses a template-matching technique. The proposed algorithm was designed to derive the time and possible angles of injection by comparing a search area with a template. The algorithm is able to vaccinate various sizes of flatfish, even when they are loaded at different angles. We validated the performance of the proposed algorithm by analyzing the injection error under randomly generated loading angles. The proposed algorithm allowed an injection rate of 2000 per hour on average. Vaccination of flatfish with a body length of up to 500mm was possible, even when the orientation of the fish was random. The injection errors in various sizes of flatfish were very small, ranging from 0 to 0.6mm.

• International Journal of Control, Automation, and Systems
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• v.4 no.4
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• pp.405-413
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• 2006

A novel approach based on genetic algorithms (GA) is developed to find a global minimum-jerk trajectory of a space robotic manipulator in joint space. The jerk, the third derivative of position of desired joint trajectory, adversely affects the efficiency of the control algorithms and stabilization of whole space robot system and therefore should be minimized. On the other hand, the importance of minimizing the jerk is to reduce the vibrations of manipulator. In this formulation, a global genetic-approach determines the trajectory by minimizing the maximum jerk in joint space. The planning procedure is performed with respect to all constraints, such as joint angle constraints, joint velocity constraints, joint angular acceleration and torque constraints, and so on. We use an genetic algorithm to search the optimal joint inter-knot parameters in order to realize the minimum jerk. These joint inter-knot parameters mainly include joint angle and joint angular velocities. The simulation result shows that GA-based minimum-jerk trajectory planning method has satisfactory performance and real significance in engineering.