Nested Optimization of Oil-Circulating Hydro-Pneumatic Energy Storage System for Hybrid Mining Trucks

In order to recover and utilize the potential energy of mining trucks efficiently, this paper proposes a nested optimization method of a novel energy storage system. By analyzing the multi-objective optimization problem of the oil-circulating hydro-pneumatic energy storage system, a nested optimization method based on the advanced adaptive Metamodel-based global optimization algorithm is carried out. Research shows that this method only requires a short time to solve the complex nonlinear hybrid optimization problem and achieves better results. The optimized energy storage system has higher system efficiency, energy density, and volume utilization rate, thus obtaining a smaller system volume and weight. Verified by the bench experiment of its powertrain, the hydro-pneumatic hybrid mining truck with the optimized energy storage system significantly reduces its fuel consumption and CO₂ emission. Thus, it lays the foundation for the practical application of hydro-pneumatic hybrid mining trucks.

DESIGN AND EXPERIMENTAL STUDY OF THE COMB-TYPE HARVESTING TEST BENCH FOR CERASUS HUMILIS

A comb-type harvesting test bench was designed to address low fruit collection rate and theoretical analysis and simulation analysis of the harvesting process were carried out in this work. Single factor simulation experiment and bench experiment were carried out, and fruit collection rate was used as the evaluation index. The motor speed, bending angle of comb teeth and radial diameter of comb teeth arrangement were selected as the experimental factors. Results showed that the collection rate decreased with the increase of motor speed; and increased with the increase of the bending angle of comb teeth or the radial diameter of comb teeth arrangement. The orthogonal experiment of three-factor and three-level quadratic rotation centre combination was performed. The results showed that motor speed had the largest effect on collection rate, followed by radial diameter of comb teeth arrangement and bending angle of comb teeth. The optimal parameter combination was predicted by the response surface model as follows: motor speed of 25 r/min, bending angle of comb teeth of 120°, radial diameter of comb teeth arrangement of 868.45 mm and correspondingly the collection rate reached 91.51%. Based on actual harvesting efficiency and the machining problems of the test bench, the bench experiment was performed with the motor speed of 25 r/min, the bending angle of comb teeth of 120°, the radial diameter of comb teeth arrangement of 900 mm, and the collection rate was 93.82%. The relative error with the predicted optimal result was 2.48%, achieving the purpose of improving the collection rate.

A New GNSS Interference Detection Method Based on Rearranged Wavelet–Hough Transform

Since radio frequency interference (RFI) seriously degrades the performance of a global navigation satellite system (GNSS) receiver, interference detection becomes very important for GNSS receivers. In this paper, a novel rearranged wavelet–Hough transform (RWHT) method is proposed in GNSS interference detection, which is obtained by the combination of rearranged wavelet transform and Hough transform (HT). The proposed RWHT method is tested for detecting sweep interference and continuous wave (CW) interference, the major types of GNSS interfering signals generated by a GNSS jammer in a controlled test bench experiment. The performance of the proposed RWHT method is compared with the conventional techniques such as Wigner–Ville distribution (WVD) and Wigner–Hough transform (WHT). The analysis results show that the proposed RWHT method reduces the influence of cross-item problem and improves the energy aggregation property in GNSS interference detection. When compared with the WHT approach, this proposed RWHT method presents about 90.3% and 30.8% performance improvement in the initial frequency and chirp rate estimation of the GNSS sweep interfering signal, respectively. These results can be further considered to be the proof of the validity and effectiveness of the developed GNSS interference detection method using RWHT.

Research of Data Processing Algorithms from Fiber Optic Sensors

The article considers the phenomenon of splitting the spectrum of the reflected signal from fiber-optic sensors (FOS) based on fiber Bragg gratings (FBG), due to which errors in calculating the strain values in diagnostic systems of the stress-strain state occur. The physical principles of splitting and their influence on the diagnostic system as a whole are considered. Various algorithms are proposed to solve the splitting problem, followed by their comparison. The optimal algorithm for processing the digitized optical spectra of signals from FOS was estimated using a mathematical model using real strain indicators from a bench experiment. FOS deformation data were obtained during an experiment on a bench for bending metal levers and were compared with strain gauges.

Distribution of Polycyclic Aromatic Hydrocarbons in Sunken Oils in the Presence of Chemical Dispersant and Sediment

The formation of sunken oils is mainly dominated by the interaction between spilled oils and sediments. Due to their patchiness and invisibility, cleaning operations become difficult. As a result, sunken oils may cause long-term and significant damage to marine benthonic organisms. In the present study, a bench experiment was designed and conducted to investigate the quantitative distribution of polycyclic aromatic hydrocarbons (PAHs) in sunken oils in the presence of chemical dispersant and sediment. The oil sinking efficiency (OSE) of 16 priority total PAHs in the sediment phase was analyzed with different dosages of dispersant. The results showed that the synergistic effect of chemical dispersant and sediment promoted the formation of sunken oils, and the content of PAHs partitioned in the sunken oils increased with the increase of dispersant-to-oil ratios (DORs). Furthermore, with the addition of chemical dispersant, due to the solubility and hydrophobicity of individual PAHs, the high molecular weight (HMW) PAHs with 4–6 rings tended to partition to sediment compared with low molecular weight (LMW) PAHs with 2–3 rings. The synergistic effect of chemical dispersant and sediment could enhance the OSE of HMW PAHs in sunken oils, which might subsequently cause certain risks for marine benthonic organisms.

Investigation of the technology of mutual navigation and orientation of small space vehicles flying in formation

The paper presents the problem of ensuring support of the flight of a group of small spacecraft (microsatellites) taking into account the small mutual distances between them. The purpose of using the orbital constellation specified is to create a radio communication system to control remote objects like unmanned aerial vehicles and ground robots located in hard-to-reach areas of the Earth from the Central ground station. To reduce the cost of microsatellite design, it was decided to rigidly fix the receiving and transmitting antennas on their housings and use the spatial orientation of the entire apparatus for antenna guidance. This seriously complicated the tasks of navigation and orientation of microsatellites in a formation and required the development of a new method for determining the orientation of a single microsatellite. The essence of the method is to process the image obtained by means of a video camera mounted on a nearby microsatellite. We used methods of computer vision. The results of mathematical modeling simulation, as well as the results of full-scale bench experiment confirming the efficiency of the proposed method are presented.