LeGO-LOAM-SC: An Improved Simultaneous Localization and Mapping Method Fusing LeGO-LOAM and Scan Context for Underground Coalmine

Simultaneous localization and mapping (SLAM) is one of the key technologies for coal mine underground operation vehicles to build complex environment maps and positioning and to realize unmanned and autonomous operation. Many domestic and foreign scholars have studied many SLAM algorithms, but the mapping accuracy and real-time performance still need to be further improved. This paper presents a SLAM algorithm integrating scan context and Light weight and Ground-Optimized LiDAR Odometry and Mapping (LeGO-LOAM), LeGO-LOAM-SC. The algorithm uses the global descriptor extracted by scan context for loop detection, adds pose constraints to Georgia Tech Smoothing and Mapping (GTSAM) by Iterative Closest Points (ICP) for graph optimization, and constructs point cloud map and an output estimated pose of the mobile vehicle. The test with KITTI dataset 00 sequence data and the actual test in 2-storey underground parking lots are carried out. The results show that the proposed improved algorithm makes up for the drift of the point cloud map, has a higher mapping accuracy, a better real-time performance, a lower resource occupancy, a higher coincidence between trajectory estimation and real trajectory, smoother loop, and 6% reduction in CPU occupancy, the mean square errors of absolute trajectory error (ATE) and relative pose error (RPE) are reduced by 55.7% and 50.3% respectively; the translation and rotation accuracy are improved by about 5%, and the time consumption is reduced by 2~4%. Accurate map construction and low drift pose estimation can be performed.

Field Measurements for Traffic Noise Reduction in Highway Tunnels Using Closed-Cell Aluminum Foam Board

In order to explore the sound absorption and noise reduction performance of closed-cell aluminum foam in the tunnel, the field test of the sound absorption performance of aluminum foam board was carried out based on the installation of aluminum foam board in the whole line of Haoshanyu Tunnel on Qinglan Expressway. Combined with the existing loudspeaker test and typical tunnel measurements, a new field test method for the noise reduction performance of closed-cell aluminum foam board was proposed for two different working conditions including fixed-point pure tone sound source condition and mobile vehicle sound source condition. The testing results of the new methods were analyzed, and it showed that the closed-cell aluminum foam has good sound absorption property at the frequency spectra between 250 Hz and 1000 Hz, and the farther away from the sound source, the better the sound absorption effect. In the research on the noise reduction effect of actual vehicle, it was found that the insertion loss of the closed-cell foam aluminum board is about 4 dB(A), which indicated that the closed-cell aluminum foam can play a certain noise reduction effect in the tunnel.

THE QUALITY OF BEE QUEENS OBTAINED BY DIFFERENT METHODS

Honeybees can only live and work in a bee colony. There is normally only one queen bee in a standard bee colony. It is the family's only fully matured female and the mother of young queen, drone, and worker bees. When a bee colony loses its queen bee and is unable to reproduce a new one, it eventually dies. Timely change of queen bees every 2 years, as well as increasing and maintaining the strength of bee colonies are the main zootechnical measures to maintain optimal life of bees and get the maximum amount of products from them. The presence of the queen bee in the bee family of honey bees fully influences their flight activity in collecting bee pollen. In its absence, the harvesting of pollen and its processing, as well as the extraction of wax and the construction of honeycombs, the cultivation of brood, and the collection of nectar are significantly slowed down and then completely stopped. With the advent of the uterus, all the functions of the family as a whole biological system are restored. Therefore, the quality of queens is a determining factor in the viability and productivity of the bee colony. The aim of the study was to compare the quality of reproductive function of queen bees of Apis mellifera sossimai and Apis mellifera carpatica breeds in different ways of obtaining them, and the impact on productivity of the bee colony. To carry out experimental work in the apiary, three control groups and two experimental groups were formed, with nine bee colonies in each group. In the first group, the queen bees were artificially breeded from the nursery, in the second group - fistulous queens bees, and in the third - the swarm queen bees. The apiary is situated on a 50-50 meter plot of land. Hives are used to keep bee colonies. Bees are kept in the apiary of the Ukrainian field breed. A pollinating honey area is available at the apiary. A winter house, a mobile vehicle, and a suitable chamber for honey pumping are all available at the apiary. Mustard is sown around the apiary every year. According to the study, big full-fledged queen bees are born in a healthy, physiologically complete bee colony. When the strength of a bee colony was increased, the queen bees were born 30 mg lighter. The number of fallopian tubes of queen bees raised with a biological integrity breach is 185,1 ± 7,3, while the number of fallopian tubes of queen bees raised with biological integrity is 207,6 ± 7,4. If the bees bring nectar and pollen during the breeding process, the queen bees are born huge, but without the forage а little and with poor executive abilities. It makes no difference how strong the foraging is; even 200 – 300 g of nectar and pollen per day has a positive impact on the quality of queen bees produced. Fistula uteruses had higher egg production compared to swarms in the same conditions of colony development.

Indoor Positioning Method Based on Infrared Vision and UWB Fusion

Ultra-wideband (UWB) has broad application prospects in the field of indoor localization. In order to make up for the shortcomings of ultra-wideband that is easily affected by the environment, a positioning method based on the fusion of infrared vision and ultra-wideband is proposed. Infrared vision assists locating by identifying artificial landmarks attached to the ceiling. UWB uses an adaptive weight positioning algorithm to improve the positioning accuracy of the edge of the UWB positioning coverage area. Extended Kalman filter (EKF) is used to fuse the real-time location information of the two. Finally, the intelligent mobile vehicle-mounted platform is used to collect infrared images and UWB ranging information in the indoor environment to verify the fusion method. Experimental results show that the fusion positioning method is better than any positioning method, has the advantages of low cost, real-time performance, and robustness, and can achieve centimeter-level positioning accuracy.

Design and Construction of Smart Vehicle Security System Using GPS and Spy Cam

Aims: Vehicle security is critical in today's world because car thefts are on the rise. robbery, and impersonation are among the crimes committed against automobiles. As a result, keeping track of and safeguarding vehicles has grown to be a significant problem in modern life. Study Design: The system combines GPS (Global Positioning Service), GSM (Global System for Mobile Communications), and Spy Cam technologies interfaced with an Arduino UNO to track the location of a car in real time. Methodology: Short Message Service (SMS) messages are sent to the user or Vehicle authority mobile phone together with images of the current vehicle operator when SMS with the word "Track" is composed and sent to the SIM number inserted into the GSM module. BLYNK Android application serves as database for storing and retrieving cloud information when requested. Results: The vehicle current location and the image of the current user will be displayed on Google Maps application of the sender. This technology enhances mobile vehicle security and avoid loss and impersonation. An SMS security warning is also sent to the owner when there is a lot of movement in front of the camera. Conclusion: This system helps in detection and reporting of vehicle theft in real time. It can be employed in individual cars since it is affordable; also vehicle safety authorities can employ this technology to help them secure vehicles better.

Fuzzy Controller for Simplified Model of Mobile Vehicle Steering Booster

The article is aimed on the possibility of fuzzy control of an experimental device that represents the simplified model of automobile steering booster. The main part of model consists of a graphical unit illustrating the control of speed and supporting torque. Based on the structure of fuzzy controller, various counts and configurations of fuzzy sets were defined, whereby the relevant results were achieved by their application on controlled system.

Dynamics-Based Piecewise Constant Control of Omni-Vehicle

In this paper, we consider the dynamics of a mobile vehicle moving under control on a perfectly rough horizontal plane. The vehicle consists of a horizontal platform and three omni-wheels that can rotate independently. An omni-wheel has freely rotating rollers on its rim [1]. We use its simplest model: an omni-wheel on a perfectly rough plane is modelled as a rigid disk with a constraint that its contact point velocity directed perpendicular to the disk's plane. The vehicle is controlled by three direct current motors in wheels' axes. Two terms model torques generated by motors: the rst one is proportional to the voltage, the second one is proportional to the value of the angular velocity of a wheel (counter-electromotive force). We study constant voltage dynamics and boundary-value problems for arbitrary initial and nal mass center coordinates, course angles and their derivatives using a piecewise constant control with one switching point. This problem is reduced to a system of algebraic equations for some specific (symmetric) vehicle model. We numerically model the system and analyze the possibility of optimization. For another vehicle configuration, we get the solution as numerical parametric continuation starting from the solution for the symmetric vehicle.