End Of Arm Research Articles

Research Status of Robot Grab Detection Based on Vision

With the progress of science and technology and the continuous improvement of living standards, robots are more and more widely used in life and production, and robot grasping technology is also constantly improving. In practical application, accurate grasp detection of target objects is an important part of robot grasping task. In this paper, the parallel two-fingered gripper is used as the end of the robot arm's grasping, and the research status of grasping detection, which is the key part in the grasping process of the robot arm based on vision, is summarized. The 2D planar grasping and 6-DOF spatial grasping are compared and analyzed in detail. At the same time, it also summarizes the commonly used evaluation indexes of capturing data sets and capturing detection, and points out the challenges faced by vision-based robot capturing and the future direction of solving these challenges.

Molecular and cytogenetic dissection of stripe rust resistance gene Yr83 from rye 6R and generation of resistant germplasm in wheat breeding.

Rye 6R-derived stripe rust resistance gene Yr83 in wheat background was physically mapped to fraction length (FL) 0.87-1.00 on the long arm by non-denaturing-fluorescence in situ hybridization (ND-FISH), Oligo-FISH painting and 6R-specific PCR markers.Stripe rust resistance gene Yr83 derived from chromosome 6R of rye (Secale cereale) “Merced” has displayed high resistance to both Australian and Chinese wheat stripe rust isolates. With the aim to physically map Yr83 to a more precise region, new wheat- 6R deletion and translocation lines were produced from derived progenies of the 6R(6D) substitution line. The non-denaturing fluorescence in situ hybridization (ND-FISH) patterns of 6R were established to precisely characterize the variations of 6R in different wheat backgrounds. Comparative ND-FISH analysis localized the breakpoints of 6RL chromosomes relative to Oligo-pSc200 and Oligo-pSc119.2 rich sites in deletion lines. Molecular marker and resistance analyses confirmed that Yr83 is physically located at the fraction length (FL) 0.87-1.00 of 6RL and covers the corresponding region of 806-881 Mb in the reference genome of Lo7. Oligo-FISH painting demonstrated that the region carrying Yr83 is syntenic to the distal end of long arm of homoeologous group 7 of the Triticeae genome. The developed wheat-6R lines carrying the Yr83 gene will be useful for breeding for rust resistance.

Modeling and Dynamics Analysis on Pseudo-Rigid-Body for the Swing Vibrator of the Caudal-Fin-Like Valve-Less Pump

A bio-inspired swing vibrator applied in fluid driving has the characteristics of a large deformation and rigid-lexible structure. Currently, there is a shortage of influential theories and methods to analyze its vibration. This research established a dynamic model for studying the bionic rigid-flexible swing vibrator based on pseudo-rigid-body theory. The weak coupling relationship between vibration arm DOF and flexible caudal-fin DOF was proposed by comparing the diagonal elements with the characteristic matrix's anti-diagonal elements. Analysis results showed that the presence of a flexible caudal-fin had minimal impact on the vibration modes of the vibration arm. The flexible caudal-fin vibration could be treated as a dynamic response that uses the vibration arm's end as a foundation. Experimental studies were conducted, and a laser Doppler vibrometer was used to measure the vibrator's vibration modes. The experimental results indicated that whether the vibrator works in water or in air, the presence of a flexible caudal-fin had little impact on the resonance frequency of the vibration arm. Finally, experimental results were discussed based on theoretical analysis and conclusions. This paper provides an academic tool for modeling, optimization, and a working mechanism analysis on the rigid-flexible swing vibrator.

Simulation of a robot arm that can supplant the dynamic activities of human arm

The research was tenaciously conducted to model and simulate a robot arm using MATLAB Simulink software. The research activities included modification of a robot arm that mimics the controlling performance of a real human arm in MATLAB and the controlling effects of each joint as per the angle of rotation of the robot arm. The controlling moment (forces) of the robot arm was mathematically modeled. Euler-Lagrange equation of motion was applied to determine vector of control moments (forces). During the simulation process, the first to achieve was to model equations of motion in MATLAB symbolically and then (further) to generate function blocks directly in Simulink followed by use of Sims cape toolbox to model the robot arm similar to 3D modeling. The robot arm end effecter followed certain reference trajectory as computed torque chosen in feed forward plus PD (Proportional Derivative) controller in feedback division. Effective control of the robot arm was ensured by connecting the robot arm to a personal computer (PC) using a microcontroller. The complete control process was accomplished through two divisions of CUBLOC microcontroller program (to write code of interference between PC and the robot arm) and MATLAB Program (containing serial communication code and the graphical user interface). The stages employed in the activities of the complete system functions consist of kinematics, trajectory planning and a controller. The output was tested and it showed that the simulated robot arm performed the dynamic activities, particularly the control, of a real human arm in the software environment.

Practical Blood Flow Restricted Bench Press On Forearm Blood Flow And Vasodilatory Capacity

Traditional whole-body resistance exercise is known to improve forearm blood flow (FBF) and vasodilatory capacity (VC). However, the effects of upper-body resistance exercise with and without practical blood flow restriction (pBFR) on FBF and VC are unclear. PURPOSE: To evaluate the effects of bench press with and without pBFR on FBF and VC in resistance-trained men. METHODS: Fourteen resistance-trained men (23 ± 3 years old) participated in the study. FBF, forearm vascular conductance (FVC), peak blood flow (BFpeak) and area under the curve (AUC) were assessed using venous occlusion plethysmography at rest and after low-load bench press with pBFR (LL-pBFR), traditional high-load bench press without pBFR (HL), and control (CON). The LL-pBFR utilized of 4 sets of 30, 15, 15, and 15 repetitions at 30% 1-repetition maximum (1RM) with 30 seconds rest between sets, and two knee wraps were wrapped at the proximal end of both arms to achieve pBFR. The HL consisted of 4 sets of 8 repetitions at 70% 1RM with 60 seconds rest between sets. The CON consisted of supine rest for 10 minutes. A repeated measures ANOVA was used to evaluate the conditions (LL-pBFR, HL, CON) across time (rest, recovery) on FBF and VC. RESULTS: There were time-by-condition interactions (p < 0.001) for FBF, FVC, and AUC such that FBF (LL-pBFR: rest: 3.1 ± 1.6 ml/100 ml/min; recovery: 7.2 ± 4.5 ml/100 ml/min; HL: rest: 3.7 ± 1.8 ml/100 ml/min, recovery: 6.1 ± 2.3 ml/100 ml/min; and CON: rest: 3.7 ± 1.6 ml/100 ml/min; recovery: 2.8 ± 2.1 ml/100 ml/min), FVC (LL-pBFR: rest: 0.041 ± 0.020 ml/min/100 ml/mmHg; recovery: 0.095 ± 0.060 ml/min/100 ml/mmHg; HL: rest: 0.048 ± 0.021 ml/min/100 ml/mmHg, recovery: 0.077 ± 0.028 ml/min/100 ml/mmHg; and CON: rest: 0.048 ± 0.022 ml/min/100 ml/mmHg; recovery: 0.035 ± 0.029 ml/min/100 ml/mmHg), and AUC (LL-pBFR: rest: 76.3 ± 31.5 ml/100 ml/min; recovery: 124.9 ± 44.1 ml/100 ml/min ; HL: rest: 83.8 ± 28.8 ml/100 ml/min, recovery: 132.7 ± 54.1 ml/100 ml/min; and CON: rest: 81.5 ± 39.2 ml/100 ml/min, recovery: 74.8 ± 45.5 ml/100 ml/min) were significantly elevated after LL-pBFR and HL compared to rest and CON with no difference between LL-pBFR and HL. However, there was no change for BFpeak. CONCLUSION: These data suggest that LL-pBFR and HL significantly increase forearm blood flow and vasodilatory capacity in a similar fashion.

A Pilot Study Comparing Algorithmic Adaptive Conventional Stimulation with High-Dose Stimulation in Chronic Pain Patients

Spinal cord stimulation is an effective method of treatment for chronic pain. We previously showed that programming using accelerometry was advantageous for paresthesia-based stimulation. However, programming can be labor intensive. Here we focus on standardized programming for both accelerometer-based paresthesia-induced programming (termed "shuffle") and high-dose (HD) subthreshold programming with stimulation delivered over the T9-10 interspace. In this prospective cross-over study, patients received 4 weeks of shuffle programming and 4 weeks of HD programming in a randomized order. In both intervals, contacts overlying T9-10 were programmed. Pain scales with measurements of activity and sleep were collected at the end of each study arm and compared with preoperative baseline scores. Twelve patients were enrolled, with 10 patients completing this study. Compared with baseline, during the HD study period, significant improvements were seen in worst pain of week (P= 0.03) and current pain (P= 0.04) as rated on Numeric Rating Scale scores and walking on the Activity Test (P= 0.012). No difference was seen from baseline compared with shuffle stimulation or in shuffle stimulation compared with HD stimulation. In this pilot study, we demonstrated that HD stimulation at T9-10 is superior to algorithmic programming of paresthesia-based stimulation. These results compared with our previous work with shuffle suggest that paresthesia-based stimulation may necessitate stimulation of additional contact locations and additional programming to optimize. This algorithmic programming of paresthesia-based stimulation continues to warrant exploration.

A novel topology to improve commutation failure immunity of HVDC based semi-controlled lc oscillator submodule

With the continuous increase of the commutation capacity of the DC project, the commutation failure has more severe impact on the transmission of active and reactive power, which seriously threatens the safe and stable operation of the power grid. A novel topology is proposed to improve the commutation failure immunity of LCC-HVDC (Line-Commutated-Converter High Voltage Direct Current). With semi-controlled LC oscillator sub-modules paralleled at both ends of the valve arm, the topology can not only increase the commutation voltage, but also can make the valve arm thyristor current zero-crossing early to turn off, thereby speeding up the commutation. Firstly, the topology and operating principle of sub-module are introduced. Additionally, the inductance and capacitance parameters in the sub-module are designed. Finally, the simulation results show that LCC-HVDC with semi-controlled LC oscillator sub-modules can be immune to commutation failure to a great extent. Compared with the solution of connecting the H-bridge sub-modules in series in the valve arm, the topology is more capable of resisting commutation failure under the unit converter capital cost.

First record of Acromitus flagellatus (Maas, 1903) (Cnidaria: Scyphozoa) swarm from the world’s largest deltaic ecosystem, the Sundarbans, India

The present study describes the first record of Acromitus flagellatus (Maas, 1903) swarm from the east coast of India, Bay of Bengal. Specimens of A. flagellatus were collected from the estuarine waters of Saptamukhi river channel, of the Sundarbans deltaic region during February 2021. The exumbrella was 160 ± 40 mm in diameter, with oral arms measuring 115 ± 45 mm and possessing a single long flagellum at the distal end of each oral arm. A. flagellatus swarm had an abundance of 5200 ± 440 ind. m−3. Sea surface temperature and salinity in the study area were 25.3 ±0.7°C and 24.5 ± 0.5 ‰ respectively. Common phytoplankton species encountered were Biddulphia sinensis, Planktoniella blanda and P. sol; while microzooplankton comprised mostly of larval forms of invertebrate metazoans. Mesozooplankton species during A. flagellatus swarm were dominated by Centropages orsinii, Bestiolina similis, Subeucalanus subcrassus, Clytia simplex, Pleurobrachia globosa, Zonosagitta pulchra and Hyperia macrocephala. Our study points to the non-specific, opportunistic feeding pattern of A. flagellatus across different trophic levels, from phytoplankton to fish and will extend the distribution of A. flagellatus up to the Sundarbans delta of the Bay of Bengal.

Neogene history of fluvial to shallow marine successions in the Kendari Basin, SE Sulawesi, Indonesia

AbstractCollision between Australia and SE Asia began in Sulawesi, the world's eleventh‐largest island, in the Early Miocene and subsequently Neogene sediments were deposited largely in coastal to shelf environments throughout the island. These sediments have been assigned to the Celebes Molasse, previously considered as a single post‐orogenic unit deposited unconformably on pre‐Neogene sedimentary, metamorphic and ophiolitic rocks. The most complete and extensive sequences of Neogene sediments are in the Kendari Basin, situated at the southern end of the SE Arm of Sulawesi, where an outcrop‐based sedimentological study was undertaken to interpret depositional environments, palaeogeography and stratigraphy. The oldest Neogene sediments are shallow marine carbonates and deltaic siliciclastics of the Bungku Formation. They are unconformably overlain by the Upper Miocene Pandua Formation which consists of sediments deposited in a variety of environments including braided river channels, fluvio‐tidal channels, tidal flats, mouth bar complex and shoreface deposits. A Mio‐Pliocene subaerial unconformity separates the marginal marine serpentinite‐rich sediments of the Pandua Formation from the overlying fluviatile quartz‐rich Langkowala Formation. The sediments of the lower part of the Langkowala Formation include conglomeratic channel fill, while the sediments of the upper part are transgressive deposits decreasing in maximum grain‐size, marked by a reduction in channel/overbank ratio and increasing tidal influence. The transgressive Pliocene Eemoiko Formation is characterised by transgressive lags or onlap shell beds and deposits of a landwards‐backstepping carbonate platform. The improved understanding of the Kendari Basin will aid the interpretation of the sedimentation history of frontier basins surrounding SE Sulawesi, many of which have not yet been drilled.

Comprehensive genetic analysis in first or second trimester pregnancy loss using chromosomal microarray with single nucleotide polymorphism probes

To explore possible genetic causes associated with early pregnancy loss using chromosomal microarray analysis (CMA) with single nucleotide polymorphism (SNP) probes. A retrospective review was performed by the CMA of samples from 961 patients who spontaneously aborted in our hospital before the 20th week of pregnancy. (1) The total chromosome abnormality rate in miscarriage samples was 54.44% (515/946), including single chromosome abnormality (39.53%), two chromosome abnormality (2.22%), multi-chromosome abnormality (0.42%), triploidy or hypertriploidy (4.86%), copy number variants (CNVs) in 41 cases (4.33%), regions of homozygosity (ROH, 0.74%), mosaic (2.22%) and chimera (0.11%). (2) CNV analysis of 41 cases showed that 85.36% were pathogenic and likely pathogenic, 12.20% were classified as clinical significance unknown and 2.44% were interpreted as likely benign; (3) Among the cases of ROH, 2 cases shown whole-genome homozygosity and 1 case had completely homozygous at chromosome 21. The homozygous regions in 2 cases were located at the end of the short arm of chromosome 16, suggesting the mechanism of ROH in such cases could be the result of isodisomy. Chromosome abnormality is an important genetic factor causing pregnancy loss. The application of CMA with SNP probes can indeed improve the detection rate of chromosome abnormalities and evaluate the risk of reproductive fertility in patients with pregnancy loss.

Molecular Cytogenetics Reveals Mosaicism in Human Umbilical Vein Endothelial Cells

Primary human umbilical vein endothelial cells (HUVECs) are consistently the most reliable in vitro model system for studying the inner lining of blood and lymphatic vessels or the endothelium. Primary human cells originate from freshly isolated tissues without genetic manipulation and generally show a modal number of 46 chromosomes with no structural alterations, at least during early passages. We investigated the cytogenetic integrity of HUVECs with conventional (G-banding) and molecular cytogenetic methods (spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH)). Our G-band data shows two X-chromosomes, confirming these HUVECs originate from a female donor. Notably, some cells consistently exhibit an unfamiliar banding pattern on one X chromosome toward the distal end of the long arm (Xq). Our FISH analysis confirms that approximately 50% of these HUVECs have a deletion of the Xq terminal region. SKY analysis indicates that the deleted region is apparently not integrated into any other chromosome. Finally, we demonstrated the presence of a similar Xq deletion in the daughter cell line, EA.hy926, which was generated by fusing HUVECs with A549 (a thioguanine-resistant clone of adenocarcinomic human alveolar basal epithelial cells). These findings will advance comprehension of HUVECs biology and will augment future endothelial studies.

Design and Workspace Analysis of Drilling Arm of Mining Anchor Drilling Robot

Bolt support is the main way of underground roadway support in coal mines in China. At present, there are some problems in domestic coal mines, such as low efficiency and poor safety. In view of the above problems, a structural scheme of omni-directional multi angle automatic roof bolter is designed. Firstly, based on the D-H method, the kinematics model of the drill arm structure of the anchor drilling robot to the roof and side of the working environment is established, and the space analysis of the four drill arms is carried out; At the same time, due to the design of the drill arm of the anchor drilling robot, the left and right drill arms of the equipment extend, rotate and work at the same time. Combined with the MATLAB kinematics model, the experiment is carried out to simulate the spatial position of the end of the drill arm of the anchor drilling robot. At the same time, the research results show that the robot can quickly replace the anchor drilling arm and ensure the quality of all-round anchor drilling, and the robot can meet the requirements of all-round support.

Safe physical human-robot interaction: A quasi whole-body sensing method based on novel laser-ranging sensor ring pairs

Non-contact detection is a competitive method for ensuring safety in close human-robot interaction (HRI). However, existing sensor configuration methods have difficulty satisfying the requirements for covering a wide range of sensing zones with fewer spots and a low-cost, low-complexity processing system. In this study, we developed a novel laser-ranging sensor configuration comprising sensors mounted on ring pairs, thereby implementing quasi whole-body sensing and cooperative location with fewer sensors. Each sensor ring pair was composed of double sensor rings mounted at opposite ends of robot arms. Based on the cone detection zone of each laser-ranging sensor, an optimisation of the configuration parameters showed that the maximum sensing volume coverage could be obtained when the laser-ranging sensors on each sensor ring were mounted in a tilted and biased form at certain angles. According to detection data and robot arm kinematics, a cooperative location model was also established to estimate the intervention position. Furthermore, we presented a self-occlusion geometric detection method for the robot, so as to identify cases in which the robot body entered the detection zone of the sensor ring pairs. To validate the efficacy of the proposed methods, experiments on quasi whole-body sensing, cooperative location, and self-occlusion detection were conducted with a UR10 robot. The experimental results show that the proposed sensor ring pair and detection method can effectively detect an approaching human and effectively estimate the intervention position and self-occlusion, allowing for efficient and safe cooperative performance with humans.

Human joints estimation system of rescue robot with occlusion

The human body is often in a partially visible state during rescue at the disaster site. At the same time, when the human body is grasped, the camera located on the actuator at the end of the robotic arm cannot fully bring the human body into the field of view. The existing human pose estimation algorithms do not perform well in this situation, and a joint detection method that can estimate the complete human pose through partial human body information and can perform data refresh in real time is required. We use the occlusion part classification module to extract the weight vector, re-weight it and the joint features extracted from AlphaPose, and add human body geometric constraints when generating 3D human body joints to obtain more accurate 3D human body joint positions. Finally, the robot is successfully used to complete the human grasping experiment, which verifies the effectiveness of the algorithm.

Robust Robotic 3-D Drawing Using Closed-Loop Planning and Online Picked Pens

This article develops a flexible and robust robotic system for autonomously drawing on 3-D surfaces. The system takes 2-D drawing strokes and a 3-D target surface (mesh or point clouds) as input. It maps the 2-D strokes onto the 3-D surface and generates a robot motion to draw the mapped strokes using visual recognition, grasp pose reasoning, and motion planning. The system is flexible compared to conventional robotic drawing systems as we do not fix drawing tools to the end of a robot arm. Instead, a robot recognizes and picks up pens online and holds the pens to draw 3-D strokes. Meanwhile, the system has high robustness thanks to the following crafts: First, a high-quality mapping method is developed to minimize deformation in the strokes. Second, visual detection is used to reestimate the drawing tool&#x2019;s pose before executing each drawing motion. Third, force control is employed to compensate for noisy visual detection and calibration and ensure a firm touch between the pen tip and the surface. Fourth, error detection and recovery are implemented to deal with slippage and other anomalies. The planning and executions are performed in a closed-loop manner until the strokes are successfully drawn. We evaluate the system and analyze the necessity of the various crafts using different real-world tasks. The results show that the proposed system is flexible and robust to generate robotic motion that picks up the pens and successfully draws 3-D strokes on given surfaces.

Intentional Blocking Based Photoelectric Soft Pressure Sensor with High Sensitivity and Stability.

Soft pressure sensors have recently attracted considerable attention because of their applications in human-machine interface, soft robotics, and prosthetics. However, there remain some challenges in achieving satisfactory performance (e.g., high sensitivity, wide sensing range, high stability) for soft pressure sensors. This article reports an intentional blocking based photoelectric pressure sensor. Two different blocking methods are investigated: the single-row-pyramid blocking and the double-row-pyramid blocking. The sensor has a simple structure, which is made of a light-emitting diode, photosensitive element, and silicone sensor shell. Experiments demonstrate that the sensor has a high sensitivity (the maximum sensitivity is 48.07 kPa-1, and the minimum measurement pressure is 0.8 Pa), large pressure-sensing range (the sensing range is up to 120 kPa), superior stability (a drift about 0.4% over 12,130 repetitive cycles at 0-80 kPa), low drift (< ±0.2% in different 3-day testing), negligible hysteresis, and high signal-to-noise ratio (over 55 dB). By mounting the pressure sensor at the end of a robotic arm, the robot can detect subtle collisions (such as touching a balloon through a pinpoint). In addition, this article fabricates a tactile glove based on the proposed pressure sensor and shows the application of this glove for music playing and object weighing. This study provides a new structure for photoelectric sensors to increase sensitivity and also provides a more convenient way to fabricate photoelectric pressure sensors.

Design of Pick and Place Robot

The popular concept of a robot is of a machine that looks and works like a human being. The industry is moving from current state of automation to Robotization, to increase productivity and to deliver uniform quality. The industrial robots of today may not look the least bit like a human being although all the research is directed to provide more and more anthropomorphic and humanlike features and super-human capabilities in these. One type of robot commonly used in industry is a robotic manipulator or simply a robotic arm. It is an open or closed kinematic chain of rigid links interconnected by movable joints. In some configurations, links can be considered to correspond to human anatomy as waist, upper arm and forearm with joint at shoulder and elbow. At end of arm a wrist joint connects an end effect which may be a tool and its fixture or a gripper or any other device to work.

Low-Dimensional-Approximate Model Based Improved Fuzzy Non-Singular Terminal Sliding Mode Control for Rigid-Flexible Manipulators

The dynamic characteristics of rigid-flexible manipulators involve complex rigid-flexible coupling phenomena, which essentially comprise a nonlinear distributed parameter system with infinite degrees of freedom. Consequently, it results in challenges to the manipulator’s precise positioning. This study combined a state feedback module and a fuzzy non-singular terminal sliding mode to suppress vibration and deformation. Using the improved fuzzy strategy and non-singular terminal sliding mode control, an adaptive dynamic supplementary control law is proposed. The results based on MATLAB simulation and a built hardware experiment show that this method is effective and superior. While realizing the accurate positioning of the end of the manipulator, the vibration of the end of the flexible arm is significantly suppressed. This method has a high tracking performance, which enables accurate positioning of the manipulator terminal and provides strong robustness under the action of bounded external interference.

Activity Subspaces in Medial Prefrontal Cortex Distinguish States of the World.

Medial prefrontal cortex (mPfC) activity represents information about the state of the world, including present behavior, such as decisions, and the immediate past, such as short-term memory. Unknown is whether information about different states of the world are represented in the same mPfC neural population and, if so, how they are kept distinct. To address this, we analyze here mPfC population activity of male rats learning rules in a Y-maze, with self-initiated choice trials to an arm end followed by a self-paced return during the intertrial interval (ITI). We find that trial and ITI population activity from the same population fall into different low-dimensional subspaces. These subspaces encode different states of the world: multiple features of the task can be decoded from both trial and ITI activity, but the decoding axes for the same feature are roughly orthogonal between the two task phases, and the decodings are predominantly of features of the present during the trial but features of the preceding trial during the ITI. These subspace distinctions are carried forward into sleep, where population activity is preferentially reactivated in post-training sleep but differently for activity from the trial and ITI subspaces. Our results suggest that the problem of interference when representing different states of the world is solved in mPfC by population activity occupying different subspaces for the world states, which can be independently decoded by downstream targets and independently addressed by upstream inputs.SIGNIFICANCE STATEMENT Activity in the medial prefrontal cortex plays a role in representing the current and past states of the world. We show that during a maze task, the activity of a single population in medial prefrontal cortex represents at least two different states of the world. These representations were sequential and sufficiently distinct that a downstream population could separately read out either state from that activity. Moreover, the activity representing different states is differently reactivated in sleep. Different world states can thus be represented in the same medial prefrontal cortex population but in such a way that prevents potentially catastrophic interference between them.

Karyotypic analysis and isolation of four DNA markers of the scleractinian coral Favitespentagona (Esper, 1795) (Scleractinia, Anthozoa, Cnidaria).

We performed conventional and molecular cytogenetic studies on the Favitespentagona Esper, 1795, a scleractinian coral mostly found along the west coast of Japan. Karyotype analysis of F.pentagona by G-banding revealed a karyogram containing a homogenously staining region (HSR) on chromosome 10 in more than 50% of the examined metaphase spreads. This HSR consisted of sequences from 18S ribosomal RNA (rRNA) genes, as demonstrated by fluorescence in situ hybridization (FISH) and DNA sequencing. We highlighted the development of four chromosomal FISH markers from repetitive genes such as U2 small nuclear RNA linked to 5S rRNA sequence (U2 snRNA-5S), 18S rRNA, histone H3, and uncharacterized gene FP-9X. The chromosomal locations of the U2 snRNA-5S and 18S RNA were on the terminal end of long arm of chromosomes 2 and 10, respectively, while the histone H3 and the uncharacterized gene were located near the centromeres of chromosomes 1 and 9, respectively. These FISH markers will improve the karyotyping of F.pentagona from mitotic preparations which helps in widening our understanding of coral genetic structure and chromosome organization. In addition, these improvements in karyotyping will provide the basis in constructing of chromosome-level genome assembly for F.pentagona.