Adaptive Fault-Tolerant Formation Control for Quadrotors with Actuator Faults

In this paper, we investigate the fault-tolerant formation control of a group of quadrotor aircrafts with a leader. Continuous fault-tolerant formation control protocol is constructed by using adaptive updating mechanism and boundary layer theory to compensate actuator fault. Results show that the desired formation pattern and trajectory under actuator fault can be achieved using the proposed fault-tolerant formation control. A simulation is conducted to illustrate the effectiveness of the method

COMPUTER SIMULATION OF THE PESTICIDE DEPOSITION DISTRIBUTION IN HORIZONTAL DIRECTION SPRAY

Abstract: The objective of this study is taken to realize pesticide precision spray of fruit trees and the other crops and reduce the deposition losses outside the canopy when the real time sensing technology was used in the pesticide target spray. In this paper the Pesticide solution deposition distribution experiments were conducted with two different volume median diameter (VMD) hollow cone nozzles fixed in horizontal direction, to investigate the influence of spray pressure and spray ground speed on the spray deposition region. The probability distribution model of the pesticide deposition was constructed based on the experiments, and the pesticide spray distribution range was simulated by using Matlab statistic toolbox. The simulation result showed that the spray pressure and the ground speed had the great influence on the maximum spray distance. With the increase of the spray speed, the spray deposition distribution range decreases gradually, when the nozzle 200 is under the speed above 1.20km/h and nozzle 300 is under the speed above 2.22km/h, the deposition range was reduced greatly. So the computer simulations make a reference for the choice of the spray control parameters

Study on the Technologies of Loss Reduction in Wheat Mechanization Harvesting: A Review

Wheat harvesting is one of the most important links in the whole wheat production process. In China, the wheat planting areas are wide, and the patterns are diversified. In addition, the problem of harvest losses caused by the numerous brands and low performance of domestic combine harvesters has always existed. Any losses during harvesting will result in less income for the farmers. Therefore, according to the actual situation of mechanized wheat harvesting and the losses occurring within different parts of the harvester, it is of great significance to select the appropriate loss reduction methods to effectively reduce wheat harvest losses. In accordance with the problems of loss during mechanized harvesting, this research first points out the main losses in the operation of a wheat combine harvester, then introduces sensor monitoring technology for grain harvesting loss and intelligent control technology for the combine harvester and analyzes their application to loss reduction in mechanized wheat harvesting. Finally, we put forward conclusions and suggestions on this loss reduction technology for wheat mechanization harvesting in order to provide a reference for reducing the losses and promoting the sustainable development of modern agriculture

Alkali Recovery of Bauxite Residue by Calcification

Bauxite residue (red mud) generated during alumina production is a highly alkaline solid waste. The red mud is mainly stored on land, but it can cause harm to the surrounding environment and human health. The transformation of red mud into soil is a feasible method for the large-scale disposal of red mud, but alkali removal is the key process that controls the transformation of red mud into soil. In this study, the calcification dealkalization of red mud with a small particle size was carried out below 100 °C. The results show that the sodium in red mud is predominately distributed in small particles, mainly because the lattice alkali and alkali present between the crystals are exposed to the surface of red mud particles by ball milling. The dealkalization process was controlled by the internal diffusion of the shrinking-core model (SCM), and the apparent activation energy was 23.55 kJ/mol. The dealkalization rate and the Na2O content of dealkalized red mud reached 92.44% and 0.61%, respectively. The dealkalization rate increased with increasing reaction time, reactant concentration, and leaching temperature, and this result was consistent with the results of the kinetic study. In addition, calcification enhances the flocculation of particles, so the filtration performance of red mud improved

Design and Testing of the Peanut Pod Cleaning Device

Due to the design of peanut harvesters and cleaners, peanut pods are often mixed with soil, gravel, peanut straw, and other impurities. To solve this problem, this study focused on designing a peanut pod cleaning device by integrating a negative pressure centrifugal fan, a hydrometric cleaning sieve, and a reversible long-mesh cleaning sieve. The relative motion of the peanut pod on the sieve was discussed, its stress analyzed, the design parameters of the sieve and fan determined, and the operation of the device was monitored by using sensors, which accurately recorded and adjusted the working parameters. Finally, the key parameters were tested, and the results showed that the design requirements were met at a vibration frequency of 5.5 Hz, a hydrometric cleaning sieve inclination of 15°, a reciprocating long mesh cleaning sieve inclination of 5°, and a fan speed of 1500 rev/min; the mean loss is 2.26%, and the mean impurity is 3.18%. The findings can be used to provide technical support and reference for the development of peanut pod cleaning devices