Neuro-fuzzy system based proportional derivative gain optimized attitude control of CubeSat under LEO perturbations.

Prompt attitude stabilization is more challenging in Nano CubeSat due to its minimal capacity, weight, energy, and volume-constrained architecture. Fixed gain non-adaptive classical proportional integral derivative control methodology is ineffective to provide optimal attitude stability in low earth orbit under significant environmental disturbances. Therefore, an artificial neural network with fuzzy inference design is developed in a simulation environment to control the angular velocity and quaternions of a CubeSat by autonomous gain tuning of the proportional-derivative controller according to space perturbations. It elucidates the dynamics and kinematics of the CubeSat attitude model with reaction wheels and low earth orbit disruptions, i.e., gravity gradient torque, atmospheric torque, solar radiation torque, and residual magnetic torque. The effectiveness of the proposed ANFIS-PD control scheme shows that the CubeSat retained the three-axis attitude controllability based on initial quaternions, the moment of inertia, Euler angle error, attitude angular rate, angular velocity rate as compared to PID, ANN, and RNN methodologies. Outcomes from the simulation indicated that the proposed controller scheme achieved minimum root mean square errors that lead towards rapid stability in roll, pitch, and yaw axis respectively within 20 s of simulation time.

Infected Ixodes ricinus ticks are attracted by electromagnetic radiation of 900 MHz.

The electromagnetic field (EMF) is known to influence functions of the nervous, cardiovascular and reproductive systems of many animals, including ticks. The aim of this study was to test the behavior of ticks in the presence of radio-frequency EMF. For testing, 160 adult male and 140 adult female unfed Ixodes ricinus ticks were used. Individuals were exposed to 900 MHz EMF in the Radiation-Shielded Tube (RST). Ticks were attracted to the irradiated area. This effect was significantly stronger for ticks infected with Rickettsia spp., suggesting that pathogens can alter the ticks' response to environmental stimuli. These results lead to the question of whether man-made EMF may have an impact on I. ricinus activity and, as such, be a contributing factor to the ongoing changes in the distribution of the tick and its pathogens currently observed in Europe and elsewhere.