Height online monitoring device and closed-loop control method for laser cladding additive forming

Abstract

The invention discloses a height online monitoring device and closed-loop control method for laser cladding additive forming. The online monitoring device comprises a cladding forming unit and a monitoring control unit. The cladding forming unit comprises a laser device, a cladding head and a matrix. The monitoring control unit comprises an image taking unit, a connecting frame, an image processing unit, a control unit and an execution mechanism unit. In the closed-loop control method, the image taking unit is fixed to laser cladding equipment to move along with a cladding nozzle, images including the cladding nozzle and a molten bath in the cladding additive forming process are acquired in real time, and the image processing unit is utilized for carrying out pixel processing on the images; the outlines of the cladding nozzle and the molten bath in the cladding additive forming process are extracted, and the forming thickness of a single cladding layer is obtained; and the forming height of the formed cladding layer is obtained through layer-by-layer thickness accumulation, the lifting height of a cladding spray head of the next layer is corrected in real time in a self-healing interval, process parameters are optimized in good times, and forming height closed-loop control is achieved.

Description

technical field [0001] The invention belongs to the field of advanced manufacturing technology and precision measurement and control technology, and relates to laser cladding and laser additive manufacturing, in particular to an online monitoring device for laser cladding additive forming height and a closed-loop control method. Background technique [0002] Laser cladding additive forming technology, its geometric feature is three-dimensional assembly and accumulation, and its physical feature is a rapid melting process of local area extension. After layering the CAD model of the entity, under the rapid scanning irradiation of the laser spot, the material follows the path specified by the program to form small molten pools point by point, and the small molten pools are rapidly melted and solidified successively. A single pass is cured one by one to form the final part. [0003] The lifting height of the cladding nozzle is the key factor to achieve high-quality laser claddi...

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Problems solved by technology

[0007] In order to solve the problems of inappropriate lifting height of cladding nozzles and inconsistent cladding heights in the above-mentioned laser cladding and additive forming process, the present invention adopts online monitoring and regulation means to realize the control of the lifting height and forming height of laser cladding additive forming cladding nozzles, A laser cladding additive forming height online monitoring device and closed-loop control method are proposed. During the forming process of each cladding layer, the working distance is monitored in real time. After the single cladding layer is formed, the single cladding layer is extracted. Forming thickness, the forming height of the formed cladding layer is obtained by accumulating the layer-by-layer thickness, and the lifting height of the next layer of cladding nozzle is corrected in real time within the self-healing interval, and the process parameters are optimized in a timely manner to realize the closed-loop control of the forming height

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