3-(Pyridin-4-ylmeth­oxy)phenol

In the title compound, C12H11NO2, the phenolic ring is inclined at an angle of 32.70 (1)° with respect to the pyridine ring. In the crystal, inter­molecular O—H⋯N hydrogen bonds link the mol­ecules into C(11) chains along [001]

catena-Poly[[[aqua­(pyridine-4-carboxyl­ato-κN)silver(I)]-μ-hexa­methyl­ene­tetra­amine-κ2 N:N′] dihydrate]

In the title compound, {[Ag(C6H4NO2)(C6H12N4)(H2O)]·2H2O}n, the AgI atom shows a distorted triangular pyramidal geometry,, formed by two N atoms from two hexa­methyl­ene­tetra­amine (hmt) ligands and one N atom from a pyridine-4-carboxyl­ate (4-pdc) ligand and one water mol­ecule. The hmt ligands bridge the Ag atoms, forming a chain along [001]. The carboxyl­ate group of the 4-pdc ligand is uncoordinated. O—H⋯O hydrogen bonds between the water mol­ecules and carboxyl­ate groups stabilize the structure

Bis[6-(1H-benzimidazol-2-yl-κN 3)pyridine-2-carboxyl­ato-κ2 N,O]cobalt(II) dihydrate

In the title compound, [Co(C13H8N3O2)2]·2H2O, the CoII atom has a distorted octa­hedral environment defined by four N atoms and two O atoms from two 6-(1H-benzimidazol-2-yl)pyridine-2-carboxyl­ate ligands. In the crystal, the complex mol­ecules and uncoordinated water mol­ecules are linked via N—H⋯O and O—H⋯O hydrogen bonds, forming a two-dimensional supra­molecular structure parallel to (010). π–π inter­actions are present between the imidazole, pyridine and benzene rings [centroid–centroid distances = 3.528 (2), 3.592 (2), 3.680 (2) and 3.732 (3) Å]

Poly[diaqua­bis­[μ-1-hy­droxy-2-(imidazol-3-ium-1-yl)ethane-1,1-diyldiphospho­nato]tricopper(II)]

In the title coordination polymer, [Cu3(C5H7N2O7P2)2(H2O)2]n, one CuII atom is five-coordinated by five O atoms from three 1-hy­droxy-2-(imidazol-3-ium-1-yl)ethane-1,1-diyldiphospho­nate (L) ligands in a distorted square-pyramidal geometry. The other CuII atom, lying on an inversion center, is six-coordinated in a distorted octa­hedral geometry by four O atoms from two L ligands and two O atoms from two water mol­ecules. The five-coordinated CuII atoms are linked by phospho­nate O atoms of the L ligands, forming a polymeric chain. These chains are further linked by the six-coordinated Cu atoms into a layer parallel to (01). N—H⋯O and O—H⋯O hydrogen bonds connect the layers into a three-dimensional supra­molecular structure

Self-Healing Control Framework Against Actuator Fault of Single-Rotor Unmanned Helicopters

Unmanned helicopters (UHs) develop quickly because of their ability to hover and low speed flight. Facing different work conditions, UHs require the ability to safely operate under both external environment constraints, such as obstacles, and their own dynamic limits, especially after faults occurrence. To guarantee the postfault UH system safety and maximum ability, a self‐healing control (SHC) framework is presented in this chapter which is composed of fault detection and diagnosis (FDD), fault‐tolerant control (FTC), trajectory (re‐)planning, and evaluation strategy. More specifically, actuator faults and saturation constraints are considered at the same time. Because of the existence of actuator constraints, usable actuator efficiency would be reduced after actuator fault occurrence. Thus, the performance of the postfault UH system should be evaluated to judge whether the original trajectory and reference is reachable, and the SHC would plan a new trajectory to guarantee the safety of the postfault system under environment constraints. At last, the effectiveness of proposed SHC framework is illustrated by numerical simulations