In recent years, with the reduction of demographic dividend, machine replacement of labor has become a trend. SCARA robots are widely used in electronic product industry, pharmaceutical industry and food industry because of their small size, high accuracy, relatively flexible movement, and much cheaper than ordinary vertical multi-joint robots. In this paper, a mature solution based on SCARA robot is proposed through the study of automatic sausage feeder.
At present, in food packaging, the front-end packaging is easy to be automated because the products are relatively regular, and the back-end products are irregular, which is basically manually completed. Due to the difficulty in controlling the hygiene of manual packaging and the difficulty in increasing the output, it has seriously affected the efficiency of the entire line, and urgently needs automated equipment to make up for it.
The SCARA robot has 3 rotating joints, whose axes are parallel to each other, and are positioned and oriented in the plane. The other joint is the moving joint, which is used to complete the movement of the end piece perpendicular to the plane. The position of the wrist reference point is determined by the angular displacements Φ1 and Φ2 of the two rotating joints and the displacement z of the moving joint, that is, p = f (Φ1, Φ2, z). The structure of this type of robot is light and fast, and its maximum movement speed can reach 10m / s, which is several times faster than that of general articulated robots. It is most suitable for plane positioning and vertical assembly operations. For example, quickly move a small object from one conveyor to another and arrange them. The two-rod structure connected in series, similar to a human arm, can be extended into a limited space for operation and then retracted, which is suitable for moving and picking up objects.
Take the automatic feeding of sausages as an example. At present, the sausages sold on the market are filled by a sausage filling machine and then sent to a steam oven for steaming. Then the sausages are manually cut off from the middle partition and placed in a turnover box. The sausages are manually placed in the grooves of the film under the stretch film machine. Due to the irregularity of sausages, it is difficult to achieve automatic feeding with conventional equipment. The traditional way of feeding sausages is mainly manual. A basket of sausages is placed directly above the stretch film machine, and then the sausages are manually placed on the lower film of the stretch film machine. This feeding method is relatively inefficient, labor-intensive, and difficult to control. Since the existing stretch film machine has always used manual feeding, the loading position is very small. If a parallel robot is used, only one parallel robot can be installed. The feeding efficiency of one parallel robot is still low and cannot meet the output demand. Due to the relatively small size of the SCARA robot, a reasonable layout method can be used to arrange two units, so that it can meet the production requirements in a limited space.
In order to solve the problem that each irregular package of sausages packed with aluminum ham clips can be accurately grasped by the robot, the robot must be equipped with "eyes", that is, equipped with a vision system, and the SCARA robot cooperates with the vision system. The eyes closed are completely equivalent to human functions, so that the problem of sausage irregularities can be solved.
In packaging machinery, especially the rear food packaging, the production of some products is still subject to seasonal restrictions, such as ice cream and moon cakes, which are produced only at specific times each year. Manual packaging is used, which brings troubles in production management. Automated equipment replaces labor. Based on cost and return considerations, some companies are still hesitant to adopt robots. The low cost of SCARA robots can completely solve this problem. The collaborative work of multiple robots on the same production line and the integration of peripheral systems can create streamlined and efficient robot workstations, present greater flexibility and gradually realize intelligent production, achieve efficient automation, increase production flexibility, and increase production capacity.