Laser Navigation System Research Articles

Разработка обобщенного алгоритма расчета энергетических характеристик электронно-оптических компонентов лазерной навигационной системы, функционирующей в условиях космического вакуума

The article highlights the components of a laser navigation system and analyzes them. A mathematical model of an optical navigation system formed by a radiation source, a transmission medium (space vacuum) and a receiver are constructed. A technique for estimating the energy characteristics of the photosensitive matrix of the orbiter's receiver has been developed. Based on the constructed technique, an algorithm was developed for calculating the energy characteristics of the electron-optical components of the lunar beacon according to the given energy characteristics of the light-sensitive matrix and the optical system of the orbiter. Examples of practical calculations for lunar day and lunar night are given. The correctness of the results obtained in the examples of calculations was checked. The algorithm developed during the study can be used to select electro-optical components while solving the problem of creating a navigation system based on laser beacons. Object of research: laser navigation system. Subject of research: a generalized algorithm for calculating the energy characteristics of the electro-optical components of laser navigation system operating in space vacuum. Main results: a generalized algorithm for calculating the energy characteristics of the electron-optical components of laser navigation system and a mathematical model of a navigation system formed by a radiation source, a transmission medium (cosmic vacuum) and a receiver included in it.

Combined Treatment of Post-Thrombotic Macular Edema with Navigation Laser Coagulation and Intravitreal Administration of Angiogenesis Inhibitors

At present about 16.4 million people in the world suffer from retinal venous occlusions (RVO). The pathophysiology of RVO includes changes in the vascular wall, blood flow, blood clotting. The key role in the pathogenesis of this group of diseases is played by ischemia and retinal hypoxia, leading to neovascularization. Macular edema (ME) is the most common complication of retinal vein occlusions. Optical coherence tomography-angiography (OCTA) is considered as an informative and highly sensitive method for diagnosing macular edema (ME) and ischemic zones in RVO. Intravitreal administration of glucocorticosteroids and/or angiogenesis inhibitors is the priority treatment method for macular edema in RVO. The combination of antiangiogenic therapy and laser treatment is promising. The navigation treatment technology is implemented under the conditions of the Navilas 577 system. The Navilas 577 laser navigation system is a laser coagulator with a tracking system and a fundus camera. The possibility of planning the operation, superimposing the results of OCTA on a fundus image makes the treatment faster, more accurate, and minimizes damage to healthy tissues.Purpose: to evaluate the results of target topographically oriented threshold laser coagulation in the treatment of post-thrombotic ME using theNavilas 577 laser navigation system following intravitreal administration of angiogenesis inhibitors.Materials and methods. There was performed a prospective study of the results of navigation laser treatment on the Navilas 577 device after intravitreal injections of angiogenesis inhibitors in 14 patients (14 eyes), aged 51 to 83 years, with macular edema up to 390 μm due to the branch central retinal vein occlusion. Laser treatment was performed within 2 weeks to 1 month following the last injection of angiogenesis inhibitors. The zones of ischemia in the macula were determined according to OCT-A data, imported into the Navilas 577 navigation system and superimposed on a color fundus image. Then the treatment was planned — the position of the future coagulates was marked.Results. In 3 months, there was a decrease in the height of edema from 366.5 (323;390) to 280 (270;300) μm, an increase in light sensitivity in the central retinal zone from 17 to 21.2 dB and an increase in visual acuity from 0.4 (0.3;0.5) to 0.5 (0.45;0.6).Conclusion. The combination of navigation retinal laser coagulation and angiogenesis inhibitors in the treatment of low post-thrombotic edema (less than 390 μm) gives good results; therefore, it can be justified and advisable in real clinical practice.

Stochastic simulation of a signal on a photodetector matrix of a laser navigation system

Abstract Algorithms for stochastic simulation of the signal arriving at the photodetector matrix of the aircraft navigation system are constructed. During the operation of the aircraft landing navigation system, the laser beam of the navigation system coincides in its direction with the glide path determining safe landing. Two photodetector units placed on board of the aircraft determine the glide path position in the coordinate system of the aircraft, which allows one to adjust the position of the touch point on the runway in poor visibility conditions. In this case, the estimation of the power and angular distributions of radiation recorded by the receiver of the navigation system is a relevant problem. In addition, it is interesting to study the effect of scattering of various multiplicities on the recorded signal. The algorithms developed here are based on direct statistical modelling (estimation over collisions) and local estimates of the Monte Carlo method. The calculations show that the proposed methods allow us to evaluate the efficiency of the laser navigation system in various conditions.

An automated guided logistics robot for pallet transportation

PurposeThis study aims to present an automated guided logistics robot mainly designed for pallet transportation. Logistics robot is compactly designed. It could pick up the pallet precisely and transport the pallet up to 1,000 kg automatically in the warehouse. It could move freely in all directions without turning the chassis. It could work without any additional infrastructure based on laser navigation system proposed in this work.Design/methodology/approachLogistics robot should be able to move underneath and lift up the pallet accurately. Logistics robot mainly consists of two sub-robots, like two forks of the forklift. Each sub-robot has front and rear driving units. A new compact driving unit is compactly designed as a key component to ensure access to the narrow free entry of the pallet. Besides synchronous motions in all directions, the two sub-robots should also perform synchronous lifting up and laying down the pallet. Logistics robot uses a front laser to detect obstacles and locate itself using on-board navigation system. A rear laser is used to recognize and guide the sub-robots to pick up the pallet precisely within ± 5mm/1o in x-/yaw direction. Path planning algorithm under different constraints is proposed for logistics robot to obey the traffic rules of pallet logistics.FindingsCompared with the traditional forklift vehicles, logistics robot has the advantages of more compact structure and higher expandability. It can realize the omnidirectional movement flexibly without turning the chassis and take zero-radius turn by controlling compact driving units synchronously. Logistics robot can move collision-free into any pallet that has not been precisely placed. It can plan the paths for returning to charge station and charge automatically. So it can work uninterruptedly for 7 × 24 h. Path planning algorithm proposed can avoid traffic congestion and improve the passability of the narrow roads to improve logistics efficiencies. Logistics robot is quite suitable for the standardized logistics factory with small working space.Originality/valueThis is a new innovation for pallet transportation vehicle to improve logistics automation.

Bilateral lung nodules resection by image-guided video-assisted thoracoscopic surgery: a case series

BackgroundWe demonstrated the safety and feasibility of image-guided video-assisted thoracoscopic surgery (iVATS) of bilateral lung lesions in a hybrid operating room.MethodsThis study was a retrospective analysis of a case series. A total of 7 patients with 15 small lung nodules underwent bilateral iVATS between July 2018 and May 2019. All procedures were completed within a single anesthesia procedure and performed in a hybrid operating room that had a cone-beam computed tomography (CT) apparatus equipped with a laser navigation system. The lesion characteristics, operation methods, and peri-operative clinical outcomes were summarized.ResultsA total of 7 patients with 15 resected lung nodules were analyzed. The most common pathological result of our bilateral iVATS was metastasis. The median length of hospital stay was 5 days (range from 3 to 10 days). The median right chest tube duration was 2 days (range from 1 to 8 days), and the median left chest tube duration was 3 days (range from 2 to 5 days). Only one patient had a complication during his hospitalization period. There was no surgery-related mortality observed.ConclusionsFor bilateral pulmonary nodules, the iVATS procedure seems to be a feasible and cost-effective approach.

Research on Model of Laser Navigation System and Obstacle Avoidance for Orchard Unmanned Vehicle

To explore the application of laser scanner in the navigation and obstacle avoidance on orchard unmanned vehicle, based on the SICK laser scanner, we established the global coordinate system model, the local coordinate system model and the laser polar coordinate system model and took a person as obstacle detection target and tested the perception results of SICK under different standing postures. The results showed that if the person stand 45° with the scanner, the scanner detection range is 3-6m. The errors between the laser scanner measured width and the actual width of each calibration target were within 5%. In the measuring range of 3 m, the reflectivity had no obvious influence on the measurement accuracy of laser scanner. Compared with the actual value, the average error of waist circumference data obtained by laser scanner at different standing postures was only 5.03%. The results could provide theoretical and data support for the formulation of laser navigation strategy and the development of laser navigation system.

Первый опыт коррекции роговичного астигматизма у пациентов с артифакией с применением фемтосекундного лазера и навигационной системы VERION

Первый опыт коррекции роговичного астигматизма у пациентов с артифакией с применением фемтосекундного лазера и навигационной системы VERION

Application of laser navigation system in percutaneous transthoracic needle biopsy based on a SPECT/CT platform

Objective To evaluate the value of a novel laser navigation system (LNS) designed for a SPECT/CT platform in improving efficiency of molecular imaging-guided percutaneous transthoracic needle biopsy (PTNB). Methods From January 2017 to October 2017, a total of 25 patients (17 males, 8 females, age (58.9±10.8) years) with thoracic lesions suspicious for malignancy underwent 99Tcm-methoxyisobutylisonitrile (MIBI) SPECT/CT-guided PTNB, and the hyperactivity areas were chosen as the sampling areas. Thirteen patients underwent traditional free hand puncture (control group), and 12 patients had LNS-assisted puncture (LNS group). The operation time, CT-guided times, average effective radiation dose of the two methods were compared. Two-sample t test was used to analyze the data. Results Comparing to control group, LNS-assisted PTNB puncture significantly reduced operation time ((7.6±2.2) vs (24.2±9.8) min; t=5.693, P<0.001), CT-guided times (1.9±0.9 vs 4.0±1.5; t=4.108, P<0.001) and average effective radiation dose ((7.7±0.9) vs (10.5±2.1) mSv; t=4.306, P<0.01). Conclusion The novel LNS is helpful in improving efficiency of molecular imaging-guided PTNB based on a SPECT/CT platform. Key words: Lung neoplasms; Biopsy, needle; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Lasers; Technetium Tc 99m sestamibi

Intraoperative computed tomography-guided pulmonary tumour localization: a thoracic surgeon’s learning curve

With the increasing availability of hybrid operating rooms, single-stage tumour localization and removal under intraoperative computed tomography (CT) guidance is gaining popularity. The objective of this study was to describe the learning curve for this procedure. Over a 15-month period, a single team of thoracic surgeons without experience in intraoperative CT-guided lung tumour localization performed a total of 91 procedures in 89 patients. All these procedures were conducted in a hybrid operating room equipped with cone-beam CT and a laser navigation system. The learning curve was analysed using the cumulative sum method (target success rate 90%), whereas the moving average was used as an indicator of localization time. The mean lung tumour size on preoperative CT images was 7.81 mm, whereas their mean distance from the pleural surface was 10.16 mm. The localization time (mean 21.19 min) was inversely associated with the surgeon's experience (Pearson's r = -0.6601; P < 0.001). The moving average analysis revealed that localization time stabilized after 32 procedures. There were 6 failures; of these, 2 occurred during lesion localization (as a result of needle puncture-related pneumothorax) and 4 during surgery (caused either by wire dislodgement or dye spillage). The cumulative sum analysis revealed that proficiency was achieved after 38 procedures. The mean localization time and success rates before and after procedure 38 were 32.13 min vs 13.34 min (P < 0.001) and 86.8% vs 98.1% (P = 0.078), respectively. The procedural time and success rates of intraoperative CT-guided lung tumour localization were optimized after 38 consecutive procedures.

A single-center experience of 100 image-guided video-assisted thoracoscopic surgery procedures.

The advent of image-guided video-assisted thoracoscopic surgery (iVATS) has allowed the simultaneous localization and removal of small lung nodules. The aim of this study is to detail, in a retrospective review, one institution's experience using iVATS in this clinical setting, with a special attention to efficacy, safety, and procedural details. This study was a retrospective analysis of prospectively collected data. Between October 2016 and January 2018, a total of 95 patients with 100 small lung nodules underwent iVATS. All procedures were performed in a hybrid operating room (HOR) in which a cone-beam computed tomography (CT) apparatus and a laser navigation system were present. The mean size of the 100 lung nodules was 7.94 mm, with their mean depth from the visceral pleura being 10 mm. A total of 98 nodules were successfully localized; of them, 94 were resected through a marker-guided procedure. There were four resection failures [wire dislodgement (n=2) or dye spillage (n=2)]). A significant inverse association was found between localization time (mean: 21.19 min) and the surgeon's experience (Pearson's r=-0.632; P<0.001). The mean length of hospital stay was 4.87 days and there were no perioperative deaths. In the current context of an increase in early diagnosis of lung cancer by screening programs, iVATS performed in a HOR offers a safe and efficient option for simultaneous localization and removal of small pulmonary nodules.

Assessment of radiation exposure in balloon kyphoplasty using a new navigation system

Study design: Randomized controlled trials of conventional and laser-navigated technology techniques for balloon kyphoplasty were carried out.Objective: To evaluate the effectiveness of a new laser navigation system in reducing the radiation dose in balloon kyphoplasty procedures.Material and methods: Sixty-seven randomized controlled trials involving a total of 75 lumbar vertebrae were treated. Thirty-four vertebrae were treated by regular fluoroscopic imaging alone, and the other 41 vertebrae were treated using the new laser navigation system. For each procedure the fluoroscopy dosage was documented using a Hitachi-Aloka Medical external dosimeter. The operation time was recorded.Results: The amount of radiation exposure in the control group was 870.59 ± 134.27 μSv. A significant reduction of the fluoroscopy usage in the navigated group was detected (503.5 ± 70.0 μSv (p < .0001)). In the control group, the average procedure time was 51.47 ± 8.30 minutes. The average procedure time in the navigated group was significantly reduced (39.26 ± 5.87 minutes (p < .0001)).Conclusion: The laser positioning and navigation system is an effective solution for reducing radiation exposure in balloon kyphoplasty. The increased technical effort may lead to a significant decrease of procedure time.The clinical trial No.: ChiCTR-INR-17013051.

Development of a tomato harvesting robot used in greenhouse

A tomato harvesting robot was developed in this study, which consisted of a four-wheel independent steering system, a 5-DOF harvesting system, a navigation system, and a binocular stereo vision system. The four-wheel independent steering system was capable of providing a low-speed steering control of the robot based on Ackerman steering geometry. The proportional-integral-derivative (PID) algorithm was used in the laser navigation control system. The Otsu algorithm and the elliptic template method were used for the automatic recognition of ripe tomatoes, and obstacle avoidance strategies were proposed based on the C-space method. The maximum average absolute error between the set angle and the actual angle was about 0.14°, and the maximum standard deviation was about 0.04°. The laser navigation system was able to rapidly and accurately track the path, with the deviation being less than 8 cm. The load bearing capacity of the mechanical arm was about 1.5 kg. The success rate of the binocular vision system in the recognition of ripe tomatoes was 99.3%. When the distance was less than 600 mm, the positioning error was less than 10 mm. The time needed for recognition of ripe tomatoes and pitching was about 15 s per tomato, with a success rate of about 86%. This study provides some insights into the development and application of tomato harvesting robot used in the greenhouse. Keywords: tomato harvesting robot, four-wheel independent steering, automatic navigation, binocular stereo vision system, obstacle avoidance, greenhouse DOI: 10.25165/j.ijabe.20171004.3204 Citation: Wang L L, Zhao B, Fan J W, Hu X A, Wei S, Li Y S, et al. Development of a tomato harvesting robot used in greenhouse. Int J Agric & Biol Eng, 2017; 10(4): 140–149.

Моделирование мехатронно управляемой динамической платформы c лазерной системой наведения для задач ориентирования и встреч космических аппаратов

Моделирование мехатронно управляемой динамической платформы c лазерной системой наведения для задач ориентирования и встреч космических аппаратов

Trajectory tracking and fault detection algorithm for automatic guided vehicle based on multiple positioning modules

This paper presents an implementation and experimental validation of trajectory tracking and fault detection algorithm for sensors and actuators of Automatic Guided Vehicle (AGV) system based on multiple positioning modules. Firstly, the system description and the mathematical modeling of the differential drive AGV system are described. Secondly, a trajectory tracking controller based on the backstepping method is proposed to track the given trajectory. Thirdly, a fault detection algorithm based on the multiple positioning modules is proposed. The AGV uses encoders, laser scanner, and laser navigation system to obtain the position information. To understand the characteristics of each positioning module, their modeling are explained. The fault detection method uses two or more positioning systems and compares them using Extended Kalman Filter (EKF) to detect an unexpected deviation effected by fault. The pairwise differences between the estimated positions obtained from the sensors are called as residue. When the faults occur, the residue value is greater than the threshold value. Fault isolation is obtained by examining the biggest residue. Finally, to demonstrate the capability of the proposed algorithm, it is applied to the differential drive AGV system. The simulation and experimental results show that the proposed algorithm successfully detects the faults when the faults occur.

Radiation dose and quickness of needle CT-interventions using a laser navigation system (LNS) compared with conventional method

PurposeThe aim of this study was to analyse the radiation dose and quickness of needle interventions using a Laser Navigation System (LNS-group) compared with conventional method (control-group). Materials and methodsIn this prospective, randomized, comparative study 58 patients (19 females, 39 males; mean age, 62.9 years) were punctured either with LNS (n=29) or with conventional method with a skin mark of the puncture site (n=29). In the LNS method the puncture site was marked with laser without additional CT. Thoracic and abdominal intervention was performed in 30 and 28 patients, respectively. Radiation dose and time of the procedures were analysed. Statistical significance was calculated according to the Mann–Whitney-U-test. ResultsMean target access path in the patients of the LNS group was 6.0cm (range, 3.0–10.1cm) and in the control group 6.0cm (range, 1.0–10.3cm). Time duration of complete intervention in the LNS group was 20:25min (range, 07:00–34:00min) and in the control group 28:00min (range, 13:00–51:00min). The dose-length-product (DLP) of intervention scan of the LNS group was 42.3mGycm (range, 10–125mGycm), and of the control group 59.7mGycm (range, 25–176.42mGycm). ConclusionUsing the LNS for CT-guided interventions results in faster intervention time with a lower dose.

Design of a Laser Navigation System for Substation Inspection Robot Based on Map Matching

Aimed at the deficiency of the magnetic guide and RFID parking system used by substation inspection robot now, a laser navigation system is designed, and the system structure, the method of map building and positioning are all introduced. The system performance is tested in a 500kV substation, and the result show that the repetitive precision of navigation system is precise enough to help the robot fulfill inspection tasks.

Positioning accuracy improvement of laser navigation using UKF and FIS

This paper presents positioning improvement of a laser navigation system (LNS) using the unscented Kalman filter (UKF) and fuzzy inference system (FIS) for an automatic guided vehicle (AGV). The existing AGVs mainly used a magnetic system or an inductive system as a guidance system. However, those systems have high initial facility cost and are difficult to maintain according to changes of environment, and it can drive only the designated path by sensors which are installed on. The laser guidance system is developed to solve these problems, but it also has limitations which are slow response time and low accuracy. Therefore, we propose a sensor fusion method for the AGV. The sensors used in this paper are encoders, a gyro and the LNS, and they are fused by the UKF and FIS. To analyze the performance of the proposed system, we designed a fork-type AGV for ourselves and performed the experiment that was repeated 10 times under the same working conditions. In experimental results, we verified that the proposed method could improve positioning accuracy of the LNS effectively. In addition, it was appropriate to apply a real AGV system for autonomous driving.

Оценка предельной дальности видимости маяков и пространственных ориентиров лазерной курсоглиссадной системы в различных метеоусловиях

Оценка предельной дальности видимости маяков и пространственных ориентиров лазерной курсоглиссадной системы в различных метеоусловиях

자기-자이로 유도 장치를 위한 MEMS형 자이로의 민감도 최적화

This paper presents a sensitivity optimization of a MEMS (microelectromechanical systems) gyroscope for a magnet-gyro system. The magnet-gyro system, which is a guidance system for a AGV (automatic or automated guided vehicle), uses a magnet positioning system and a yaw gyroscope. The magnet positioning system measures magnetism of a cylindrical magnet embedded on the floor, and AGV is guided by the motion direction angle calculated with the measured magnetism. If the magnet positioning system does not measure the magnetism, the AGV is guided by using angular velocity measured with the gyroscope. The gyroscope used for the magnet-gyro system is usually MEMS type. Because the MEMS gyroscope is made from the process technology in semiconductor device fabrication, it has small size, low-power and low price. However, the MEMS gyroscope has drift phenomenon caused by noise and calculation error. Precision ADC (analog to digital converter) and accurate sensitivity are needed to minimize the drift phenomenon. Therefore, this paper proposes the method of the sensitivity optimization of the MEMS gyroscope using DEAS (dynamic encoding algorithm for searches). For experiment, we used the AGV mounted with a laser navigation system which is able to measure accurate position of the AGV and compared result by the sensitivity value calculated by the proposed method with result by the sensitivity in specification of the MEMS gyroscope. In experimental results, we verified that the sensitivity value through the proposed method can calculate more accurate motion direction angle of the AGV.

The Indoor Automatic Guided Vehicle with an IR Positioning and Low-Cost Inertial Navigation System

In this study an indoor automatic guided vehicle (AGV) which is not a line-following type is constructed. Low-cost inertial navigation system (INS) and indoor positioning system (IPS) are proposed to replace the high-cost laser navigation system. These AGVs are guided by their own INS almost all the time of running in our system. The IPS constructed by infrareds is used to calibrate the accumulative errors of the inertial system after a specific time interval. Testing results show deviation is about 5% after long time and long distance of movement. This research proves the stability of this system which allows AGVs to work in warehouses by low-cost INS and IPS.