With the continuous development of society, the demand for high precision and high responsiveness of some automation equipment is increasing rapidly.
At present, the automation control technology is constantly improving, and some precise high-speed positioning control is guaranteed and widely used. Paper bag machine is a kind of equipment which forms multi-layer paper by uncoiling and gluing, and then carries out dynamic fixed-length shearing. It requires the production line to cut the paper bag dynamically according to the change of paper feeding speed at will, also known as “flying shear”. When shearing, the cutting speed should be kept in step with the paper speed or slightly faster than the paper feeding speed. Therefore, the shearing control of paper bag machine is a highly demanding problem of motion control. This paper mainly studies and designs the cutting control system of the paper bag machine. Based on the analysis of the production process and control requirements of the paper bag machine, the servo tracking cutting system of the paper bag machine is designed according to the type of “motion controller servo system touch screen”.
The system solves the problem that different bag lengths must be rotated. At the same time, the color mark tracking function is added to realize the automatic compensation of deviation.
Color label sensor: Keynes color sensor is selected, the maximum response time is 0.2us. The distance of the connecting axis is divided into three stages to be applied to the motion of the basic axis. These parts are acceleration part, constant speed part and acceleration part. Link acceleration and acceleration are set by link_acceleration and link_deceleration parameters. The constant speed connection distance is derived from the total connection distance and these two parameters. The three stages can be divided into independent MOVELINK instructions or superimposed together. The ADDAX instruction adds the target position of the superimposed axis to the trajectory of the moving axis.
ADDAX allows for two-axis superimposed motion.
Connecting two or more axes, ADDAX can also be used. The adjustment part is superimposed on the constant speed part according to the sinusoidal curve.
The rotary cutting function is realized by three curves, that is, thermostatic element each set bag length, the cutting knife rotates one circle and cuts once. Note: VR (startsynpos): start synchronization angle; VR (fsydistance): cutting tool circumference; VR (endsynpos): end synchronization angle; VR (cut length): bag length. When the cutter is cut off, the current length is zero and counted from the beginning. When the color mark is detected, the current value is compared with the theoretical value to generate a deviation. The deviation is compensated by adding Addax in the compensation section to the cutting axis. The assembly must be carried out in strict accordance with the instructions, schematic diagrams and technical specifications. To reduce interference and interference, 95% shielding wire is used for motor wire and shielding layer is firmly grounded.
Multi-core shielded twisted pair is used for encoder wire and driver is properly grounded. In this control, the analog output is used as the constant servo speed, and the driver frequency division feedback is used as the closed-loop control. Therefore, before debugging and controlling, the driver and motor are tuned and optimized dynamically, and the dynamic response of the servo system is raised as high as possible until no oscillation occurs; then the P gain of the motion control is adjusted until the following error of the axis is as small as possible and the system does not oscillate. After working continuously for a period of time, the maximum error between the actual cut bag length and the set bag length is less than 1 mm. Different bag lengths are easy to switch, just set the bag lengths from the screen.
When the color mark compensation is needed, the automatic compensation can be realized only by selecting the color mark tracking, which is very convenient and achieves the desired effect. The control system has high position control accuracy and good speed following characteristics, meets the high performance requirements of paper bag machine, flexible, high-speed, accurate and other main features, thus improving people’s work efficiency and quality, and has reference significance for the development of other high-performance shearing equipment.