Integrated Control Protocol Research Articles

Nonlinear optimal control with disturbance rejection for asteroid landing

This paper presents an optimal solution to asteroid soft landing problem, on the base of θ−D control technique and disturbance rejection mechanism. The control objective is to drive a probe to reach the surface of an asteroid with a desirable line-of-sight angle and zero velocity, eliminating the influence of external disturbance. Firstly, elementary θ−D technique is applied in the absence of disturbance to tackle the nonlinear optimal control problem. Secondly, the disturbance is estimated in the fast-estimation framework with explicitly bounded estimation error. Afterwards, an integrated control protocol is presented in a feed-forward structure by the aid of an additional variable-structure term to ensure stability under time-varying disturbance. Simulation results of the proposed approach compared with the results of elementary θ−D method and robust θ−D method are presented at the end of this paper, demonstrating the effectiveness of the proposed control protocol.

INTEGRATED CONTROL PROTOCOL (ICP) OF INK DISEASE OF CHESTNUT IN CENTRAL ITALY: PRINCIPLES AND FUTURE PERSPECTIVES

Ink disease of chestnut (Castanea sativa Mill.) caused by Phytophthora cambivora (Buisman Petri) represents one of the major threats of the cultivation in central Italy. Ink disease management largely relies on pathogen epidemiology. An Integrated Control Protocol (ICP), including management of superficial water flows, copper sulphate and metalaxyl applications, and potassium phosphite (trunk injections of potassium phosphite), has been applied in three areas in central Italy varying for location, extension, agricultural management and geomorphology. The monitoring of Phytophthora population during the protocol steps applications has been useful to identify the best combination and timing of the measures applied. One year application of ICP in larger areas resulted in a reduction of Phytophthora inoculum. Next two years perspectives will focus on the improvement of the ICP by strictly monitoring inoculum dynamic in treated and control areas.

INTEGRATED CONTROL PROTOCOL TO MITIGATE AND ERADICATE INK DISEASE IN CHESTNUT ORCHARDS

Ink disease caused by Phytophthora spp. represents a serious emergence in chestnut groves in Italy. On the basis of acquired knowledges, an integrated control protocol has been elaborated and applied in affected orchards in Central Italy. It implies, the use of potassium phosphite as inhibitor of Phytophthora spp. and inducer of acquired resistance in chestnut; the use of classical copper compounds or systemic fungicides to stop the inoculum spread; the hydrology restoration and watersheld management to avoid inoculum spread via flowing water; public awareness through appropriate behaviour in entering and exit infected areas. Evaluation of efficacy of the integrated protocol has been carried out by monitoring inoculum consistency and patterns of disease spread.