Real-time visual measurement device and method for deflection of dynamic and static load test of lifting appliance

Abstract

The invention discloses a real-time visual measurement device and method for the deflection of a dynamic and static load test of a lifting appliance. The device comprises visual measurement cameras I / II, an image acquisition controller, telescopic suspension rods I / II, an image processing computer, a visual measurement camera hanging device, a top connecting disc, a loading device, a measurement target assembly and a test piece assembly. The visual measurement cameras I / II and the image acquisition controller are mounted on the visual measurement camera hanging device; the visual measurement camera hanging device is connected with the two ends of the top connecting disc through the telescopic hanging rods I / II. The loading device and the test piece assembly are respectively arranged aboveand below the top connecting disc; the measurement target assembly is installed on the test piece assembly. According to the invention, real-time, rapid and high-precision measurement of the deflection of the lifting beam in the dynamic and static load test of the lifting appliance can be realized; the device is suitable for deflection measurement under dynamic working conditions, and the measurement precision is improved.

Description

technical field [0001] The invention belongs to the technical field of dynamic and static load tests of a spreader, and in particular relates to a real-time visual measurement device and method for the deflection of a spreader in a dynamic and static load test. Background technique [0002] The spreader refers to the appliance used to connect the crane to the suspended product and meet the lifting requirements of the product. The structure of the spreader is mainly composed of the main body of the spreader, rings, straps, lugs and so on. The main body of most of the spreaders is a rigid beam body. Displacement occurs when a beam is bent under force, and the displacement caused by bending deformation is called deflection. According to the national military standard QJ2472.1-1993 "General Technical Conditions of Spreaders for Beam Spreaders", all spreaders need to carry out dynamic and static load tests during the development process. Dynamic and static load tests are test i...

AI Technical Summary

Problems solved by technology

The steel ruler method uses a steel ruler to measure and convert the deflection of the spreader in proportion. This method has poor measurement accuracy and cannot measure dynamic deflection, which poses a safety hazard to the measuring personnel.

The hand-held laser range finder method uses a hand-held laser range finder to measure the absolute height of the lifting point and center point of the main structure of the spreader before and after loading, and can calculate the corresponding deflection. The high method has poor measurement accuracy and cannot measure dynamic deflection

The strain calculation method uses the deflection equation in material mechanics to calculate by measuring the surface strain of the beam body. This measurement method is an indirect measurement method, and the measurement accuracy cannot be measured.

The magnet hanging ruler method is to extend the deformation of the hanging point to the steel ruler through the tooling, and the reading is calculated by erecting the level gauge on the lifting car. This method is more complicated to operate and cannot measure the dynamic deflection.

The tube-sheet photogrammetry method adopts single-camera close-range photogrammetry, sticks the target on the beam body, fixes the calibration rod, and obtains the deformation amount by solving the photos. Due to the poor pertinence of this method, the preparation time in the test process is long and the measurement speed is slow. , slow data collection, complex calculation of deflection results, low overall work efficiency, and difficult dynamic measurement

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