Snake Robot with Driving Assistant Mechanism

Snake robots are composed of multiple links and joints and have a high degree of freedom. They can perform various motions and can overcome various terrains. Snake robots need additional driving algorithms and sensors that acquire terrain data in order to overcome rough terrains such as grasslands and slopes. In this study, we propose a driving assistant mechanism (DAM), which assists locomotion without additional driving algorithms and sensors. In this paper, we confirmed that the DAM prevents a roll down on a slope and increases the locomotion speed through dynamic simulation and experiments. It was possible to overcome grasslands and a 27 degrees slope without using additional driving controllers. In conclusion, we expect that a snake robot can conduct a wide range of missions well, such as exploring disaster sites and rough terrain, by using the proposed mechanism. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. T.1

뱀 로봇의 다양한 주행 모션과 동역학적 분석에 대한 연구

NⅠ. Introduction Ⅱ. Development of the snake robot 2.1 Manufacturing the robot 2.2 Development of the gait types 2.3 Driving assistant mechanism Ⅲ. Dynamic analysis 3.1 Newton-Euler method 3.2 Dynamic analysis of driving assistant mechanism Ⅳ. ConclusionMasterdCollectio

Study on the Snake Robot’s Rolling Motion and Driving Velocity

본 논문에서는 뱀을 모사한 로봇을 만들고 제자리에서 굴러가는 rolling motion을 개발하였다. 원활한 rolling motion을 수행하기 위해서 slip ring과 원형프레임이 이용되었으며, slip ring은 선이 꼬이지 않게 해주는 역할을 수행하고, 원형프레임은 모터가 바퀴처럼 굴러갈 수 있게 해주는 역할을 수행한다. Rolling motion을 수행하면 뱀 로봇의 형상은 활 모양을 이루게 되는데, 이때 gait parameter를 조정함으로써 활 모양이 변형된다. Gait parameter 중 amplitude, 즉 모터의 회전각도 범위를 조절함으로써 활의 휨 정도가 달라진다. 본 논문에서는 이와 같이 활모양의 몸의 형태와 모터의 회전각을 이용한 새로운 뱀로봇의 보행방식을 제안하고, 이에 대한 연구를 수행하였다. In this paper, we made a robot that mimics a snake and developed a rolling motion. A slip ring and a circular frame are used to perform a smooth rolling motion. The slip ring prevents the wires from being twisted, and the circular frame allows the motor to roll like a wheel. When rolling motion is performed, the shape of the snake robot becomes a bow shape. At this time, the bow shape is deformed by adjusting the gait parameter. Among the gait parameters, the degree of bending of the bow is changed by adjusting the amplitude, that is, the range of rotation angle of the motor. Comparing driving speeds according to these geometric shapes is the main content of this study. © 2022 The Korean Society of Mechanical Engineers.FALS

Hot Embossing Process Technology Forming Arbitrary Patterns in Real Time

With the development of mobile sensors and biosensors, an ultrafine process technology that can generate ultrafine patterns and has mass production capability has garnered attention recently. Unlike the existing hot embossing techniques, the impact print-type hot embossing process can generate a microscale pattern that has arbitrary pattern width and depth on a polymer film in real time using a single impact header. For this reason, this process can be applied to various industrial fields that require ultrafine patterns. However, it cannot create intricate patterns due to the limitations of the two-axis stage control system. Furthermore, its application to a mass production that requires pattern repetition is limited because of the single header system. In this paper, a three-axis impact print-type hot embossing system using a multiheader and two algorithms, the impacting coordinate-based data extraction algorithm and independent driving algorithm, to overcome the limitations of previous systems is proposed. Thanks to the multiheader and control algorithm, this process can generate repetitive patterns in real time, and it can adjust the pattern resolution by controlling the pattern extraction interval. The proposed method is thus expected to be widely applicable to industrial fields that require microscale user-defined patterns such as mobile sensors and biosensors. © 2020 Wiley-VCH GmbH1

Snake Robot with Driving Assistant Mechanism

Snake robots are composed of multiple links and joints and have a high degree of freedom. They can perform various motions and can overcome various terrains. Snake robots need additional driving algorithms and sensors that acquire terrain data in order to overcome rough terrains such as grasslands and slopes. In this study, we propose a driving assistant mechanism (DAM), which assists locomotion without additional driving algorithms and sensors. In this paper, we confirmed that the DAM prevents a roll down on a slope and increases the locomotion speed through dynamic simulation and experiments. It was possible to overcome grasslands and a 27 degrees slope without using additional driving controllers. In conclusion, we expect that a snake robot can conduct a wide range of missions well, such as exploring disaster sites and rough terrain, by using the proposed mechanism

Study of a Dot-patterning Process on Flexible Materials using Impact Print-Type Hot Embossing Technology

Here we present our study on an impact print-type hot embossing process which can create dot patterns with various designs, widths, and depths in real time on polymer film. In addition, we implemented a control system for the on-off motion and position of the impact header to engrave different dot patterns. We performed dot patterning on various polymer films, such as polyester (PET) film, polymethyl methacrylate (PMMA) film, and polyvinyl chloride (PVC) film. The dot patterns were measured using a confocal microscope, and we confirmed that the impact print-type hot embossing process produces fewer errors during the dot patterning process. As a result, the impact print-type hot embossing process is found to be suitable for engraving dot patterns on different types of polymer films. In addition, unlike the conventional hot embossing process, this process does not use an embossing stamp. Therefore, the process is simple and can create dot patterns in real time, presenting unique advantages for mass production and small-quantity batch production. © 2020 Journal of Visualized Experiments.1

Review of the Latest Research on Snake Robots Focusing on the Structure, Motion and Control Method

Unlike other types of robots, the snake robot performs unique motions and can move on various terrains such as gravel, stairs, and pipes. Therefore, snake robots are used as exploration robots, rescue robots, and disaster robots. However, the snake robot requires to choose actuators, sensors, and controllers appropriately for overcoming the real environment by using various types of gait. In this paper, we summarized research trends of snake robots for understanding the state of the art technologies of snake robots. We focused on the various development of the snake robots based on previous snake robots' literature. To look more closely at these research trends, we introduced trends of motion, actuators, sensors, kinematic structure design, control method and application that are related with the snake robots. Snake robots can conduct several motions such as sine wave, side winding, rolling, and so on. These motions are generated by servo motors, DC motors, pneumatic actuators, and smart materials like SMA, IPMC, etc. Also, snake robots require certain data from sensors and proper kinematic structure design to achieve their purposes of operation. Sensors such as camera, force sensor, distance sensor, and kinematic structure design such as passive wheel and motorized wheel can be applied in snake robot for implementing the function or increasing the driving performance. Based on these physical components, the control method is important for operating the snake robot. Navigating algorithms and overcoming terrains with restrictions on movement have been studied with a various control methods. © 2022, ICROS, KIEE and Springer.FALS

Study of a Line‐Patterning Process Using Impact Print‐Type Hot Embossing Technology

An impact print-type hot embossing process is a method for creating arbitrary patterns on polymer film in real-time. This process can form 20–100 μm dot patterns and line patterns using an impact head and a high-precision moving stage on a polymer film such as polyester (PET) film, polymethyl methacrylate (PMMA) film, polyvinyl chloride (PVC) film without the need for the embossing stamps used for conventional hot embossing processes. This technology can also create line patterns with varying widths and depths by adjusting the positions of the impact header. Moreover, the proposed process can be used to fabricate electrical channels of various widths and depths to install ultrafine electronic devices. Because the proposed method can create ultrafine patterns in real-time, using it can reduce the cost and time required for pattern modifications and process replacements. In addition, from the result of the bending test after applying the conductive ink to the line pattern, it is known that this process is suitable for making the flexible electrical channel. The advantages of this line-patterning method will contribute significantly to the current field of hot embossing to create ultrafine patterns by enabling small-quantity production of various types of products while also facilitating mass production. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim1

Spray-Dried Amorphous Solid Dispersions of Atorvastatin Calcium for Improved Supersaturation and Oral Bioavailability

Over the past few decades, the amorphous solid dispersions (ASDs) technique has emerged as a promising strategy to enhance the in vitro/in vivo characteristic of hydrophobic drugs. The low aqueous solubility and poor bioavailability of atorvastatin calcium (ATO), a lipid-lowering drug, present challenges for effective drug delivery. The objective of this work was to improve the aqueous solubility, in vitro dissolution, and oral absorption of ATO with amorphous solid dispersion technique prepared by spray-drying method. The optimized ternary formulation comprising of ATO; hydroxypropyl methylcellulose (HPMC), as a hydrophilic polymer; and sodium lauryl sulfate (SLS), as a surfactant, at a weight ratio of 1/1/0.1, showed significant improvement in aqueous solubility by ~18-fold compared to that of the free drug, and a cumulative release of 94.09% compared to a release of 59.32% of the free drug. Further, physicochemical studies via scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffraction revealed a change from the crystalline state of the free drug to its amorphous state in the ASD. Pharmacokinetic analysis in rats demonstrated 1.68- and 2.39-fold increments in AUC and Cmax, respectively, in the ASD over the free drug. Altogether, hydrophilic carrier-based ASDs prepared by the spray-drying technique represent a promising strategy to improve the biopharmaceutical performance of poorly soluble drugs

Preparation of Pyridylamido Hafnium Complexes for Coordinative Chain Transfer Polymerization

The pyridylamido hafnium complex (I) discovered at Dow is a flagship catalyst among postmetallocenes, which are used in the polyolefin industry for PO-chain growth from a chain transfer agent, dialkylzinc. In the present work, with the aim to block a possible deactivation process in prototype compound I, the corresponding derivatives were prepared. A series of pyridylamido Hf complexes were prepared by replacing the 2,6-diisopropylphenylamido part in I with various 2,6-R2C6H3N-moieties (R = cycloheptyl, cyclohexyl, cyclopentyl, 3-pentyl, ethyl, or Ph) or by replacing 2-iPrC6H4C(H)- in I with the simple PhC(H)-moiety. The isopropyl substituent in the 2-iPrC6H4C(H)-moiety influences not only the geometry of the structures (revealed by X-ray crystallography), but also catalytic performance. In the complexes bearing the 2-iPrC6H4C(H)-moiety, the chelation framework forms a plane; however, this framework is distorted in the complexes containing the PhC(H)-moiety. The ability to incorporate α-olefin decreased upon replacing 2-iPrC6H4C(H)-with the PhC(H)-moiety. The complexes carrying the 2,6-di(cycloheptyl)phenylamido or 2,6-di(cyclohexyl)phenylamido moiety (replacing the 2,6-diisopropylphenylamido part in I) showed somewhat higher activity with greater longevity than did prototype catalyst I