Jongheon Kim

Micro aerial vehicle type wall-climbing robot mechanism

Nowadays, as the building structures are getting taller and taller, the importance of maintenance or inspection of these structures is being increased. However, it has some problems due to the lack of professional manpower and there is a risk in maintaining those areas that are hard to reach, besides the high maintenance cost. The unmanned wall-climbing robots for the areas hard to reach have been researched to solve the problems. The infrastructure-based wall-climbing robots have high payload and safety but the robots need the infrastructure that should be installed on the target structure. The infrastructure is not preferred by the architects since it can be harmful to the exterior of the structure. For this reason, wall-climbing robots that do not need any infrastructure are being researched. Nevertheless, most of the non-infrastructure-based wall-climbing robots are in the laboratory level since the payload, safety and maneuverability are not satisfactory. To overcome these problems, a flight-possible wall-climbing robot mechanism is proposed in this paper. The robot is based on the quadrotor system that is a well-known aerial vehicle using four rotors. It uses thrust forces induced by the four rotors not only to fly but also to stick on the wall. The flight capability makes its maneuverability and safety greatly enhanced. The feasibility of the mechanism is shown through simulations and experiments with a prototype.

Micro-aerial vehicle type wall-climbing robot mechanism for structural health monitoring

Currently, the maintenance or inspection of large structures is labor-intensive, so it has a problem of the large cost due to the staffing professionals and the risk for hard to reach areas. To solve the problem, the needs of wall-climbing robot are emerged. Infra-based wall-climbing robots to maintain an outer wall of building have high payload and safety. However, the infrastructure for the robot must be equipped on the target structure and the infrastructure isn’t preferred by the architects since it can injure the exterior of the structure. These are the reasons of why the infra-based wall-climbing robot is avoided. In case of the non-infra-based wall-climbing robot, it is researched to overcome the aforementioned problems. However, most of the technologies are in the laboratory level since the payload, safety and maneuverability are not satisfactory. For this reason, aerial vehicle type wall-climbing robot is researched. It is a flying possible wallclimbing robot based on a quadrotor. It is a famous aerial vehicle robot using four rotors to make a thrust for flying. This wall-climbing robot can stick to a vertical wall using the thrust. After sticking to the wall, it can move with four wheels installed on the robot. As a result, it has high maneuverability and safety since it can restore the position to the wall even if it is detached from the wall by unexpected disturbance while climbing the wall. The feasibility of the main concept was verified through simulations and experiments using a prototype.

Design and analysis of a new hybrid rotary steerable system for directional drilling

Recently, shale gas has become an important energy source. Directional drilling is an imperative technology when it comes to excavating shale gas because it exists in underground in horizontally spaced areas. A rotary steerable system (RSS) enables the effective directional drilling. In general, there are two types of RSS, the point-the-bit and the push-the-bit. In this paper, a new hybrid type RSS is proposed. The hybrid type RSS has advantages of both the point-the-bit and the push-the-bit. We expect that the proposed RSS can increase the build-rate. The effectiveness of the proposed mechanism is discussed by predicting the side force.

A vision-based detection algorithm for moving jellyfish in underwater environment

This paper proposes a novel vision-based jellyfish detection algorithm in underwater environment. Since jellyfish, especially Aurelia aurita, is translucent and amorphous when projected to the 2-dimensional image, its boundary is indistinct and detecting jellyfish is very challenging. To detect moving jellyfish, two types of features that present the translucent appearance and swimming motion of jellyfish, respectively, are proposed. The proposed algorithm tracks and recognizes swimming jellyfish. The feasibility test of the proposed algorithm shows that it can detect jellyfish in underwater environment.

Embedded Drilling System Using Rotary-Percussion Drilling

The drilling technology is widely used in various fields. This technology has been developed explosively by large companies. However, most of the conventional drilling systems require large equipment such as rig and mud systems. This makes it difficult for drilling in polar or space environments where large equipment is hard to enter or carry. To solve this problem, we propose an embedded drilling system which does not requires the rig, mud system, and pipes. In this paper, the concept of embedded drilling system will be proposed and we introduce a locomotion and rotary-percussion drilling mechanism of this system. Two simulations were performed to show efficiency of the proposed system compared toss the conventional rotary drilling system.

Development of a Novel Hybrid-Type Rotary Steerable System for Directional Drilling

Unlike conventional resources, unconventional resources, such as shale gas and coal bed methane, are situated horizontally under geological formations. To exploit these resources, directional drilling and hydraulic fracturing technologies are required. In directional drilling, the dog leg severity (DLS), which indicates how much the angle changes while drilling 100 ft, is a major issue with respect to the cost and time of drilling. In this paper, we briefly review different types of directional drilling methods and propose a new hybrid-type rotary steerable system (RSS). DLS calculations based on three-point geometry for these systems are suggested. This hybrid RSS combining two conventional types of RSSs: point-the-bit and push-the-bit systems, achieves better steerability. The hybrid mechanism is implemented using hybrid pads with hydraulic cylinders and a spherical joint. The advantages of the proposed system are demonstrated by performing small-scale prototype and cement block drilling tests.

Reaction torque minimization method for keeping drilling direction of the hybrid rotary steerable system

The directional drilling system is one of the key technologies for developing unconventional resources such as shale gas and coal bed methane (CBM). There are several types of the directional drilling system such as the whipstock, bent-sub, and the rotary steerable system (RSS). Among these systems, the RSS is most advanced system. In this paper, the hybrid type RSS is developed and its experiment results of drilling cement blocks will be introduced. The experiment had a problem due to the reaction torque of the drilling system. A method of minimizing the effect of the reaction torque is proposed to solve this problem.

Development of a jellyfish reconnaissance and removal robot system using unmanned aerial and surface vehicles

Summary form only given. In this paper, a novel robot system for a jellyfish reconnaissance and removal using unmanned aerial vehicle (UAV) and unmanned surface vehicle (USV) is introduced. In recent years, overpopulated jellyfish are threatening ocean ecosystem as well as damaging to ocean-related industries such as fishery, seaside power plants, and casualties. The damage is estimated about 300M USD per year in South Korea. To resolve this problem, a jellyfish removal net towed by trawl boats and a few of devices to prevent the influx of jellyfish have been developed. However, most of these devices have the limited usage due to environmental constraints. To solve this problem using a robotic system, the jellyfish removal robot system, named JEROS (Jellyfish Elimination RObotic Swarm), has been proposed [1]. The JEROS consists of a USV and a jellyfish remover device. The USV can perform a jellyfish removal task using an autonomous navigation system. The jellyfish remover device is originally designed to shred jellyfish. It is additionally designed using a conveyor device to remove venomous jellyfish without shredding. JEROS is extended to a swarm robot system to enhance the performance of jellyfish removal [2]. The swarm robot system performs the jellyfish removal task while maintaining a formation. The UAV-type jellyfish reconnaissance system is proposed. The UAV flies over the sea along a coverage path to search a swarm of jellyfish. A camera mounted on the UAV takes images of the sea surface and a jellyfish recognition algorithm based on a deep learning finds distribution of jellyfish using the taken images. The jellyfish removal task is performed by JEROS in combination with the reconnaissance system. The reconnaissance system recognizes the distribution of jellyfish and transmits the position of the distribution to the JEROS system. The JEROS system generates a path from a starting position to the received region and follows the path. On arriving, the JEROS system remove jellyfish using the jellyfish remover device while following a coverage path.