Provided is an optical fiber measurement method and device of blade tip clearance. A multipoint orientation reflecting compensation type optical fiber is adopted to carry out distance measurement; laser emitted by a laser device in a working wavelength range is transmitted to the surface of an object to be measured through a fiber probe, is reflected back to the fiber probe after being reflected through the surface of the object to be measured, and then enters multiple channels of receiving optical fibers respectively; filtering is carried out on laser entering the receiving optical fibers through optical filters, energy of laser entering the multiple channels of receiving optical fibers in the working wavelength range after the laser is reflected by the surface of the object to be measured is obtained respectively, the energy of the laser is converted into weak current signals through photoelectric detection, the weak current signals are amplified into current or voltage signals for being collected through a signal amplification filtering circuit, comparison processing is carried out by collecting the multiplexed output current signals or voltage signals, and the distance between the optical fiber probe and the object to be measured is obtained. The invention further discloses a measurement device for achieving the method.

Optical fiber measurement method and device of blade tip clearance

The invention discloses a tip clearance measurement method based on all-fiber tip timing. The method comprises the following steps: converting measurement on length measurement in a triangle method into measurement on a tip timing signal; adopting two fiber bundle type timing sensors, and enabling emission fibers in the timing sensors to emit two beams of auto-collimation emergent light with different wavelengths; enabling receiving fibers in the timing sensors to receive moment signals when leaves approach and leave a measurement region; monitoring the rotating speed of a rotor in real time by a rotating speed synchronization sensor; performing high-speed signal acquisition and circuit module processing on all the sensor signals, and reversely calculating a distance between the end face of each sensor and each leaf tip by an upper computer through a math model. According to the tip clearance measurement method, a clearance value is ingeniously converted into a tip timing signal relevant to the clearance value, so that a measurement system is irrelative to most environmental factors such as the leaf and electromagnetic interference, and the interference resistance and the clearance measurement precision of the system are improved.

Tip clearance measurement method based on all-fiber tip timing

The invention discloses a system and a method for three-dimensional characterization of blade tip gaps and dynamic detection of optical fibers of an aero-engine. The system comprises a laser light source, a pulsed light source control circuit, a light splitter, a blade tip gap sensing probe, a pre-processing circuit, a single chip and an upper computer; the blade tip gap sensing probe comprises a reference optical fiber, an axial angle-measuring optical fiber and a circumferential angle-measuring optical fiber. The system is capable of dynamically and accurately obtaining the three-dimensional characterization of blade tip gaps of the aero-engine and is high in anti-interference capability.

System and method for three-dimensional characterization of blade tip gaps and dynamic detection of optical fibers of aero-engine

An optical fiber device for turbine blade surface temperature distribution measuring comprises an optical fiber probe, a lens set is arranged in the optical fiber probe, the lens set and the optical fiber probe are connected to four optical fiber bundles, a double-color temperature measuring system for measuring the temperature of the surface of a turbine blade is formed by the first optical fiber bundle and the second optical fiber bundle, and a reflection type displacement measuring system for measuring position information of the turbine blade is formed by the third optical fiber bundle and the fourth optical fiber bundle. The optical fiber bundles respectively correspond to one optical filter. The light paths of the first optical fiber bundle, the second optical fiber bundle and the third optical fiber are respectively provided with one photovoltaic conversion part, and the light path of the fourth optical fiber is provided with an illuminating source. The double-color temperature measuring system and the reflection type displacement measuring system are connected with a data collecting instrument which is connected with a remote monitoring system through the network. The optical fiber device can measure the temperature of the surface of the turbine blade rotating at a high speed, the temperature changing characters can be monitored online in real time, and the serious failures such as probable blade ablation in an operating combustion gas turbine are prevented in advance.

Optical fiber device and measuring method for turbine blade surface temperature distribution measuring

The invention relates to a fully-automatic cantilever type image measuring device and method, belongs to the field of measuring equipment The measuring device comprises a pedestal, and a pedestal, an operating console, a computer assembly, an image assembly, an illumination assembly and a grating scale data collection assembly are arranged on the pedestal The measuring method comprises the following steps that 1) a CCD camera, a varifocal lens and a probe are mounted from top to bottom and then on a linear guide rail in the direction Z and sleeved in a hood; 2) a workpiece is placed on a glass plate, and the illumination assembly is started; 3) movement modules in the axes X, Y and Z are started; and 4) the computer assembly analysis grating data and images to obtain a measurement result

Fully-automatic cantilever type image measuring device and method

The utility model relates to an optical fiber sensor and in particular relates to an optical fiber sensor for measuring tip clearance of rotating blades. The optical fiber sensor comprises a probe (3) and is characterized in that the probe (3) consists of single emitting optical fiber (1) and three groups of receiving optical fiber beams (2) which are tightly arranged in a three-ring mode; the single emitting optical fiber (1) is positioned at the central position; and the three groups of receiving optical fiber beams (2) are closely arranged by taking the single emitting optical fiber (1) as a center. The optical fiber sensor adopts a three-ring type optical fiber arrangement mode so as to reduce the size of the probe (3), enlarge the linear measurement range and improves the sensitivity. The optical fiber sensor is provided with three groups of receiving optical fiber beams, can acquire three groups of light intensity signals, can reduce or even eliminate the influence of the change of the tip surface reflectivity and the change of the included angle between the tip surface and the end surface of the sensor on the measurement result by performing ratio processing on the acquired three groups of light intensity signals.

Optical fiber sensor for measuring tip clearance of rotating blades

The utility model discloses a sensor automatic centering system in small-hole measurement. The system contains a pedestal, on which a supporting seat is arranged. A workbench which can slide along X and Y directions of a three-dimensional coordinate is disposed on the supporting seat. A capacitance probe is mounted at the central position of the workbench. Two symmetrical supporting rods are respectively fixed in X and Y directions of the workbench. One of the symmetrical supporting rods is provided with a laser transmitter, and the other one of the symmetrical supporting rods is provided with a laser receiver. A lead screw III driven by a Z-direction stepper motor is arranged in the Z direction of the three-dimensional coordinate at one side of the workbench. A sliding table is connected to a nut of the lead screw III. The sliding table is connected to a polished rod used for supporting a workpiece. The capacitance probe is used for measuring the aperture of the workpiece, and the capacitance probe is connected with a signal processing device. The system provided by the utility model has advantages of high measurement accuracy and rapid response.

Sensor automatic centering system in small-hole measurement

The invention discloses an automatic centering system of a sensor in hole measuring. The automatic centering system comprises a base. A support is arranged on the base. A workbench which can slide back and forth in the X direction and the Y direction of three-dimensional coordinates is arranged on the support. A capacitance probe is arranged at the center position of the workbench. Two symmetrical supporting rods are fixed in the X direction and the Y direction of the workbench respectively. A laser sending device is arranged on one supporting rod, and a laser receiving device is arranged on the other supporting rod. A lead screw III which is driven by a Z-direction stepping motor is arranged in the Z direction of the three-dimensional coordinates on one side of the workbench. A sliding table is connected to a nut of the lead screw III. The sliding table is connected with a polish rod used for supporting a workpiece. The capacitance probe is used for measuring the diameter of a hole in the workpiece, and the capacitance probe is connected with a signal processing device. The system has high measuring accuracy and is quick in response.

Liu Minjing

Papers

Optical fiber sensor for measuring tip clearance of rotating blades

Sensor automatic centering system in small-hole measurement

Automatic centering system of sensor in hole measuring