Jiusheng Bao

Aiming at the high risk and low efficiency of traditional artificial inspection methods in the complex industrial scene, this study focuses on the inspection robot and conducts research on path planning through simulation and experiment. Firstly, according to the unstructured characteristics of complex industrial scenes, in order to reduce the loop error, the Lazy Decision algorithm is introduced to improve loop detection of Cartographer algorithm. Secondly, at the level of global path planning, a feasible path objective model under multiple constraints is constructed, and the genetic algorithm is reasonably improved through adaptive adjustment of crossover and mutation probabilities, design of composite selection strategy and node deletion operator, to enhance the efficiency and smoothness of global path planning. Then, at the level of local path planning, in order to improve the safety of robot driving, path point and trajectory pose point constraints are introduced into the TEB algorithm, and an obstacle evaluation sub-function is constructed to optimize its obstacle avoidance performance, achieving the collaborative fusion of global and local path planning. Finally, the simulation and experiment of path planning are carried out. The results show that the optimized Cartographer algorithm has higher mapping accuracy, and the relative errors in the simulation and experimental scenes are reduced by 34.25% and 45.09% respectively, which effectively alleviates the problem of map ghosting. The path length, number of inflection points, and planning time of the improved genetic algorithm are reduced by up to 16.32%, 59.10%, and 42.10%, respectively. The local path planned by the improved TEB algorithm can also follow the global path well and the safety distance from the turning point is increased by 41.37%. The fusion algorithm reduces path length and driving time by 31.91% and 23.76% respectively, balancing the safety and efficiency of path planning for the inspection robot.

Trackless rubber tired vehicles (TRTV) is one of the main transportation equipment in coal mine underground auxiliary transportation systems. However, the use of explosion-proof diesel engines as power sources under harsh working conditions underground has caused intake and exhaust obstruction, leading to serious exhaust pollution problems. In response to this issue, taking WCJ5E (H) TRTV as the research object, a multi-component exhaust purification device for mining explosion-proof diesel engines was designed by comparing and analyzing exhaust purification technology routes, simulating the explosion-proof water cooling effect and exhaust purification effect of exhaust purification devices. The device consists of “exhaust gas recirculation (EGR)+diesel oxidation catalyst (DOC)+catalytic diesel particulate filter (CDPF)+explosion-proof temperature control device (EPTC).” On this basis, explosion-proof water-cooled performance tests and NRSC emission characterization tests were carried out based on the completed exhaust purification unit, and the results showed that: Under the action of the explosion-proof temperature control device, the temperature of the shell of the exhaust purification device and the temperature of the exhaust port are lower than 30°C, which could meet the requirements of explosion-proof in coal mines. After installing the exhaust purification device, the purification effect of exhaust pollutants is significant. The contents of CO, HC, NO _x , and PM are less than 0.244, 0.12, 2.526, and 0.025 g/kW h, respectively, which can meet the Non-road national IV exhaust emission standards ahead of schedule and promote the green development of explosion-proof diesel power assisted transportation vehicles in coal mines.

The core risks of unmanned truck formations in narrow curved sections of open-pit mines mainly include lateral trajectory deviation risk and longitudinal following coordination risk, which can lead to inaccurate heading angle and improper following control. Therefore, a multi-vehicle formation collaborative control method based on LQR and DMPC is proposed. The research objective is to design a collaborative control strategy that is suitable for narrow curved sections of open-pit mines, achieving precise lateral trajectory tracking and safe longitudinal following. Firstly, a multi-vehicle collaborative control scheme is designed by analyzing the transportation conditions. Secondly, the lateral dynamics model and the preview error model are established. Besides, the lateral controller based on feedforward LQR is designed. Then, based on the longitudinal dynamic characteristics of the vehicle, the multi-vehicle formation longitudinal controller based on DMPC is designed. Next, the multi-vehicle formation collaborative controller is established. Finally, the Simulink/TruckSim joint simulation model is constructed, and the unmanned experimental vehicle and open-pit mining experimental platform are designed for conducting simulations and experiments. The simulation results show that collaborative control reduces the lateral error of the following vehicle by 37.20% and the heading angle error by 36.40% when driving downhill with no load. Furthermore, collaborative control reduces the lateral error of the following vehicle by 21.95% and the heading angle error by 39.54% when fully loaded uphill. At the same time, the longitudinal following vehicle maintains a speed error of no more than 0.35 km/h and a spacing error of less than 0.30 m compared to the leading vehicle. The experimental results show that the designed formation controller controls the lateral error of the following vehicle within ±0.035 m and the heading angle error does not exceed 0.15 rad, verifying the effectiveness and adaptability of the studied formation control method.

In response to the current issues of insufficient sensitivity and large output signal errors in low-frequency vibration sensing technology, a triboelectric acceleration sensor was proposed, and its design and output characteristics were studied. The structure of the triboelectric acceleration sensor was designed, the power generation characteristics and its calculation model under different key parameters were analyzed, the sensing characteristics and its calculation model under different key parameters were studied, an optimization method for key parameters of the triboelectric acceleration sensor was proposed, and a triboelectric acceleration sensor was developed and performance testing and application experiments were conducted. The results show that the triboelectric acceleration sensor exhibits excellent dynamic response characteristics within the range of 40 Hz and 32 m/s2, with a inherent frequency of about 75 Hz and a sensitivity of 0.75 V/(m·s-2). Compared with commercial piezoelectric acceleration sensor, it has good low-frequency vibration response characteristics and long-term stability, with most of its output signals having a signal-to-noise ratio of around 35dB; Make it more suitable for completing low-frequency vibration monitoring tasks such as vehicle vibration. The research results provide a theoretical basis and technical support for enriching the design and sensing theory of triboelectric sensors, and expanding their low-frequency vibration sensing application fields.

Critical non-silting velocity, a key parameter in slurry pipeline transport systems, significantly influences operational conditions and economic viability. A lower critical non-silting velocity is advantageous for reducing energy consumption, minimizing pipeline wear, and enhancing system stability. To achieve this objective, this study proposes a method to improve the particle suspension state within slurry pipelines through the addition of a swirler. The research comprehensively investigated variations in the critical non-silting velocity under diverse conveying conditions, comparing scenarios both with and without the swirler. The results demonstrate that the swirler induces a circumferential flow within the pipeline. This flow exerts a drag force on particles, promoting their transition from a settled state to a non-silting flow regime, thereby reducing the critical non-silting velocity. For slurries characterized by low concentration, small particle size, and low density, the circumferential kinetic energy required to alter their flow state is smaller; consequently, the reduction in critical non-silting velocity is more pronounced. The calculation model of critical non-silting velocity considering the swirl characteristics was established. Compared to experimental values, the model yields an average error of 9.10% and a maximum error of 14.08%.

The trackless rubber tired vehicle (TRTV) is a kind of auxiliary transportation vehicle used for underground mining environment. It is pretty difficult to achieve stable braking performance for a hybrid TRTV with a single braking method and control strategy. Firstly, the structure of electromechanical and hydraulic coupling brake system was designed by taking the hybrid TRTV as research object. Then, the control circuit of its hydraulic brake system was determined, and the control strategy was designed according to the braking regulations of the Economic Commission for Europe (ECE). Next, a simulation comparison test was conducted, in which the battery initial SOC values was 0.7 and 0.85 respectively. And the brake system established in this paper was compared with the one in the ADVISOR under the working condition of CYC-WCQ1. Finally, the feasibility of the coupling brake system designed in this paper was verified by bench testing. The error difference between the simulation test and the bench test results was within the allowable range. The fuel consumption of the bench test is 12.38% and 13.33% higher than that of the simulation test, the HC emissions are 11.48% and 13.55% higher, the CO emissions are 10.24% and 10.75% higher, and the NOx emissions are 9.01% and 9.74% higher respectively. It is believed that this research may be valuable for both the development of reliable brake system for hybrid TRTVs used in mining industry.

Aiming at the practical problems such as complex technology and large cost investment existing in the traditional environmental perception method in obtaining the operating status of underground unmanned vehicles, an innovative perception method of key operating status for underground unmanned vehicle based on dynamic wind field in roadway is proposed, which is verified by simulation and experiment. Firstly, the typical roadway airflow structure is analyzed based on the restricted jet theory, and the wind field disturbance element model of roadway-vehicle system is constructed based on the roadway piston wind effect. Secondly, the distribution characteristics of roadway airflow are analyzed through fluid simulation software. Then, the axial and radial wind field structure of the roadway containing the unmanned vehicle is simulated and analyzed, and the internal relationship between the dynamic wind field and the key operating status of unmanned vehicle is revealed. Finally, the experimental scene of circular wind tunnel is built, and the perception of the safe and abnormal operating status for the unmanned vehicle is effectively realized based on the dynamic wind field information. The experiment results verify the rationality and feasibility of perception method of key operating status for underground unmanned vehicle based on dynamic wind field in roadway, which can make up for the limitations of the existing roadway environment perception technology, and help to improve the operating safety of underground unmanned vehicles.

Flow resistance is a critical determinant of the efficiency and economics of a slurry pipeline. This study aims to reduce pipeline resistance by integrating a swirler to enhance particle suspension. The variation laws of slurry conveying resistance with and without a swirler under various conveying conditions were investigated. Whether a swirler is present or not, the conveying resistance increases with an increase in the conveying velocity (1~6 m/s), volume concentration (10~50%), particle diameter (0.1~5 mm), particle density (1100~1500 kg/m³), and pipe inclination (0~90°). It decreases with an increase in the pipe diameter (50~200 mm). A moderate swirling intensity reduces the resistance in high-velocity large-particle slurry transport. Considering the swirling flow characteristics in the conveying pipeline, resistance loss calculation models accounting for these characteristics were established for different flow states of the slurry in the pipeline. Taking into account the swirling characteristics in the conveying pipeline, a calculation model for resistance loss of the slurry in different flow states within the pipeline was established. The average error between this model and the experimental results was 9.04%.