Method and system for real-time monitoring and controlling height of deposit by using image photographing and image processing technology in laser cladding and laser-aided direct metal manufacturing process

A method for monitoring and controlling the height of a cladding layer in laser cladding and laser-aided direct metal manufacturing, comprising the steps of

• photographing a molten pool formed by the laser cladding as images each having a certain area;
• determining a pixel representing a height of the molten pool using the image of the molten pool obtained through the photographing to calculate an actual position and height of the molten pool in real time by using an actual physical height of a certain pixel and a variation value of the actual height per pixel corrected by using a standard specimen for which the height of a cladding layer is known;
• and
• controlling a process parameter affecting the height of the cladding layer in real time to control the height of the cladding layer to reach a target height value by increasing a thickness of the cladding layer if the actual height of the molten pool is less than the target height value and by decreasing the thickness of the cladding layer whenever the actual height of the molten pool is greater than the target height value to form a cladding layer having a shape and a thickness corresponding to 2D sectional information derived from, stored sectional shaping information;
• and
• thereby correcting overshooting of the actual height at all heights above the target height.