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A semi-flush air data sensing probe is formed as an elongated bubble housing directly supported on an aircraft surface having a generally longitudinally extending rounded outer edge surface with a rounded contoured leading end. The housing has top and bottom wall surfaces extending from the supporti

A semi-flush air data sensing probe is formed as an elongated bubble housing directly supported on an aircraft surface having a generally longitudinally extending rounded outer edge surface with a rounded contoured leading end. The housing has top and bottom wall surfaces extending from the supporting surface to the rounded outer surface. The trailing end of the housing is smaller than the leading end and is contoured to provide for smooth airflow past the housing. A central longitudinally extending plane that bisects the housing and which is perpendicular to the supporting surface, forms a reference. A forwardly facing port is at the leading end and centered on the central plane, and a pair of angle of attack sensing ports are on the leading end and are symmetrically located on opposite sides of the longitudinally extending plane. A static pressure sensing port also is provided on the housing at a position along the rounded outer edge surface and spaced downstream from the leading end.

대표청구항 ▼

A semi-flush air data sensing probe is formed as an elongated bubble housing directly supported on an aircraft surface having a generally longitudinally extending rounded outer edge surface with a rounded contoured leading end. The housing has top and bottom wall surfaces extending from the supporti

A semi-flush air data sensing probe is formed as an elongated bubble housing directly supported on an aircraft surface having a generally longitudinally extending rounded outer edge surface with a rounded contoured leading end. The housing has top and bottom wall surfaces extending from the supporting surface to the rounded outer surface. The trailing end of the housing is smaller than the leading end and is contoured to provide for smooth airflow past the housing. A central longitudinally extending plane that bisects the housing and which is perpendicular to the supporting surface, forms a reference. A forwardly facing port is at the leading end and centered on the central plane, and a pair of angle of attack sensing ports are on the leading end and are symmetrically located on opposite sides of the longitudinally extending plane. A static pressure sensing port also is provided on the housing at a position along the rounded outer edge surface and spaced downstream from the leading end. otated; a buffer rod provided in a path through which the knitting yarn is to be fed from between said main roller and said driven roller to the yarn feeding port of the weft knitting machine, said buffer rod having a tip portion that is capable of being rocked and displaced around a base portion of said buffer rod, and said buffer rod being adapted to pull the knitting yarn from the path when the tip portion of said buffer rod is rocked and displaced toward one of two sides; a spring for urging said buffer rod to one of the two sides so as to pull the knitting yarn, when in the path, from the path by a predetermined length under a predetermined yarn tension; a sensor for detecting a rocking and displacement state of said buffer rod, based on an origin of the tip portion of said buffer rod, when the knitting yarn is to be pulled from the path by the predetermined length, and for sending a signal indicative of a result of the detection of the rocking and displacement state of said buffer rod; and a controller for proportion, integration and differentiation (PID) control of said servo motor based on the signal sent by said sensor, wherein said controller (i) is to supply, before knitting in the direction of the width of the fabric is started, an amount of the knitting yarn that is greater than that supplied when the tip portion of said buffer rod is positioned at a point corresponding to the origin, (ii) is to perform the PID control to include a differential component within a remainder side range from which the tip portion of said buffer rod is to be returned to the point corresponding to the origin when knitting is started and demand for the knitting yarn is rapidly increased, and (iii) is to perform the PID control so as not to include the differential component even if the tip portion of said buffer rod is on a remainder side or on an insufficient side after the tip portion of said buffer rod once passes through the point corresponding to the origin and is then transferred to within an insufficient side range in which a length of the knitting yarn to be led out from the path is smaller than that to be led out when the tip portion of said buffer rod is at the point corresponding to origin. 2. The yarn feeding apparatus of claim 1, wherein said controller is to perform the PID control based on a change in position of the yarn feeding port with respect to the fabric and a change in amount of the knitting yarn which is calculated from the knitting data such that the rocking and displacement state of said buffer rod is set within a predetermined range. 3. The yarn feeding apparatus of claim 1, wherein said controller to perform, with only the differential component, the PID control so as to include the differential component within a remainder side range, and is to perform, with a proportion component and an integral component, the PID control to include no differential component. 4. The yarn feeding apparatus of claim 1, wherein said controller (i) is to set a gain into a high gain state having an excellent follow-up property while the tip portion of said buffer rod passes from a remainder side range through the point corresponding to the origin and reaches a position at which an amplitude is maximum within and an insufficient side range and then returns toward the point corresponding to the origin to within a predetermined range, and (ii) is to switch the gain into a low gain state having excellent stability while the tip portion of said buffer rod passes through the predetermined range and returns to the point corresponding to the origin. 5. The yarn feeding apparatus of claim 4, wherein said controller is to perform, in the high gain state, the PID control to include no differential component by setting, to be the insufficient side range, a range from which the tip portion of said buffer rod is first moved to the point corresponding to the origin from a position where a large amount of the knitting yarn is