Control method of control system for automatic unwinding of carbon fiber placement machine

Abstract

The invention discloses a control method of a control system for automatic unwinding of a carbon fiber placement machine, and the system comprises an ultrasonic sensor for measuring the winding diameter of an unwinding raw material, an unwinding shaft for installing a carbon fiber raw material winding drum, a servo all-in-one machine directly connected with the unwinding shaft, and a film winding shaft for winding a covering film in the raw material winding drum, the floating roller is used for balancing the elastic force of the spring and the tension of a yarn path, the spring is connected to the floating roller, and the displacement sensor is connected to the spring. Spring elasticity is obtained through a displacement sensor, and then current yarn path tension is obtained; according to the set expected tension and the current yarn path tension, the force needing to be output by a servo all-in-one machine directly connected with the unwinding shaft is obtained through a PID algorithm; the diameter of the unwound material is measured through the ultrasonic sensor, and the torque needing to be output by the servo all-in-one machine is calculated. According to the invention, high stability and quick response performance of automatic unwinding during high-speed fiber placement of the carbon fiber placement machine equipment are realized, and various faults in the unwinding process are automatically judged.

Description

Technical Field

[0001] The present application relates to the field of carbon fiber laying machines, and in particular to a control method for a control system for automatic unwinding of a carbon fiber laying machine. Background Art

[0002] At present, carbon fiber materials are more and more widely used in low-altitude flight, aviation and aerospace fields. Carbon fiber laying machines can automatically lay out and shape narrow strips of carbon fiber prepreg.

[0003] 1. The unwinding control of carbon fiber laying machines at home and abroad mostly adopts brake method or motor speed control method.

[0004] 1) When using brakes, due to the high unwinding speed of the fiber laying machine and the great influence of metal powder on the characteristics of carbon fiber, pneumatic brakes are currently mostly used. The braking torque output is achieved by controlling the input air pressure, that is, the output of the unwinding torque. Since there is a nonlinear relationship between air pressure and braking torque, and the air pressure is not easy to control stably, the control accuracy and stability of the brake torque output are not high.

[0005] 2) When unwinding is achieved by controlling the speed of the servo motor, since the laying speed of the wire laying machine is usually relatively fast, the yarn path speed changes greatly at the moment the equipment starts and stops. The speed response of the unwinding motor is not fast enough, and the yarn is easily broken or the unwinding shaft is damaged when the equipment starts. When the equipment stops, too much yarn is fed out, causing the yarn path to fall off and the yarn needs to be re-threaded.

[0006] Second, the wire laying machine usually has multiple yarn paths for independent laying, and multiple servo motors and servo drives are arranged on the laying head at the end of the wire laying machine, which makes the wire laying head larger in size and is not conducive to laying products in a small space.

[0007] 3. Since the laying speed of the carbon fiber laying machine is usually above 300mm / s, the carbon fiber material has a certain viscosity, and the carbon fiber yarn roll has knotting phenomenon, it is easy for working failures to occur on the yarn path during the operation of the carbon fiber laying machine. At present, the failures of the carbon fiber laying machine on the yarn path are usually judged manually, which can easily lead to material loss and equipment damage during the automatic laying process. Summary of the invention

[0008] In view of the above-mentioned deficiencies in the prior art, the present application proposes a control method for a control system of an automatic unwinding machine for a carbon fiber laying machine, which directly adjusts the output torque of the servo all-in-one machine according to the current value and set value of the yarn path tension, thereby improving the accuracy and response speed of the unwinding tension control.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows: A control system for automatic unwinding of a carbon fiber laying machine, the control system comprising: A coil diameter sensor, the coil diameter sensor and the unwinding shaft are mounted on the same side of the mounting plate, the carbon fiber raw material is wound on the unwinding shaft, and the coil diameter sensor is used to detect the coil diameter of the carbon fiber raw material; A floating roller, the bottom end of which is mounted in a U-shaped groove of a mounting plate, with the roller body on the same side as the unwinding shaft, and the yarn path of the carbon fiber raw material wraps around the floating roller; a spring is provided at the connection between the floating roller and the mounting plate; A displacement sensor is installed beside the spring, a movable collar of the displacement sensor is connected to the end of the spring, and the displacement sensor is used to measure the stretched length of the spring; A servo integrated machine, wherein the output end of the servo integrated machine is directly connected to the unwinding shaft, and the servo integrated machine is used to control the unwinding torque. The PLC calculates the output torque of the unwinding shaft, that is, the output torque of the servo integrated machine, and sends it to the servo integrated machine.

[0010] Furthermore, the bottom end of the floating roller is installed in a U-shaped groove in the mounting plate, and the floating roller floats under the action of the yarn path tension and the spring elastic force.

[0011] Furthermore, the position of the floating roller and the speed of the unwinding shaft are used to realize self-diagnosis of faults during the unwinding control process.

[0012] Based on the above control system for automatic unwinding of a carbon fiber laying machine, the present application also provides a control method thereof, and the control method comprises the following steps: The distance between the roll diameter sensor and the unwinding shaft center is measured as L. According to the real-time measurement value a of the roll diameter sensor, the real-time roll diameter value d of the carbon fiber raw material is obtained as (La)*2; The spring coefficient is set to k, and the spring is in a free state when the floating roller is in the initial position. According to the displacement sensor measurement value b, the current tension value of the yarn path is obtained as f=b*k / 2; The preset value of the yarn path tension is set to X, and the PLC calculates the unwinding shaft output force F through the PID control algorithm according to the tension setting value X and the current tension value f of the yarn path.

[0013] Furthermore, the torque output by the unwinding shaft is M=F*d / 2.

[0014] Beneficial effects of the present invention: The current yarn path tension value is calculated by the coefficient of the spring installed on the yarn path floating roller and the spring displacement measurement value; the PLC obtains the unwinding shaft output force through PID operation based on the tension setting value and the current yarn path tension measurement value; the current winding diameter of the unwinding shaft is measured by the ultrasonic sensor; the PLC calculates the output torque of the unwinding shaft servo integrated machine based on the unwinding shaft output force and the current winding diameter of the unwinding shaft; the PLC controls the unwinding shaft servo integrated machine to work in torque mode, and sends the output torque value to the servo integrated machine in real time.

[0015] The unwinding shaft adopts a special servo all-in-one machine, that is, the servo motor and servo driver are combined into one. The servo driver is simplified into a circuit board and integrated with the servo motor.

[0016] The reel diameter measured by the ultrasonic sensor can be used to determine whether the material is not installed and the material is about to run out. The servo speed of the unwinding shaft can be used to determine whether there is a yarn blockage or yarn cutting failure in the yarn path. The measurement value of the displacement sensor connected to the floating roller can be used to determine whether there is a yarn knotting or yarn breakage during the laying process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the electrical architecture of the automatic unwinding control system in the embodiment of the present application; Figure 2 This is a schematic diagram of the mechanical composition of the control system for automatic unwinding of a carbon fiber laying machine used in this application; Figure 3 This is a schematic diagram of the mechanical composition of the control system for automatic unwinding of a carbon fiber laying machine used in this application; Figures 4 to 8 4 is a diagram of a yarn path fault diagnosis strategy in an embodiment. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0019] Embodiment 1:

[0020] This embodiment is a control system for automatic unwinding of a carbon fiber laying machine, and the control system includes: A coil diameter sensor, the coil diameter sensor and the unwinding shaft are mounted on the same side of the mounting plate, the carbon fiber raw material is wound on the unwinding shaft, and the coil diameter sensor is used to detect the coil diameter of the carbon fiber raw material; A floating roller, the bottom end of which is mounted in a U-shaped groove of a mounting plate, with the roller body on the same side as the unwinding shaft, and the yarn path of the carbon fiber raw material wraps around the floating roller; a spring is provided at the connection between the floating roller and the mounting plate; A displacement sensor is installed beside the spring, a movable collar of the displacement sensor is connected to the end of the spring, and the displacement sensor is used to measure the stretched length of the spring; A servo integrated machine, wherein the output end of the servo integrated machine is directly connected to the unwinding shaft, and the servo integrated machine is used to control the unwinding torque. The PLC calculates the output torque of the unwinding shaft, that is, the output torque of the servo integrated machine, and sends it to the servo integrated machine.

[0021] Furthermore, the bottom end of the floating roller is installed in a U-shaped groove in the mounting plate, and the floating roller floats under the action of the yarn path tension and the spring elastic force.

[0022] Furthermore, the position of the floating roller and the speed of the unwinding shaft are used to realize self-diagnosis of faults during the unwinding control process.

[0023] like Figures 1 to 3 As shown, the system provided in this embodiment includes an ultrasonic sensor 1, a floating roller 2, a mounting plate 3, an unwinding shaft 4, a film-rewinding shaft 5, a servo integrated machine 6, a spring 7, and a displacement sensor 8.

[0024] The ultrasonic sensor 1 is fixedly mounted on the mounting plate 3, and its measuring direction is aligned with the center of the unwinding shaft 4 to realize the measurement of the diameter of the carbon fiber roll; the bottom end of the floating roller is adjustable, and can reciprocate in the U-shaped groove of the mounting plate 3 under the action of external force; the unwinding shaft 4 is mounted on the mounting plate 3, and can rotate under the drive of the servo integrated machine, and the unwinding shaft is used to install the carbon fiber roll material; the film collecting shaft 5 is mounted on the mounting plate 3, and is used to collect the film of the carbon fiber roll, and it can rotate under the pull of the film; the servo integrated machine is fixedly mounted on the mounting plate 3, and its output end is directly connected to the unwinding shaft 4 to realize the torque control of the unwinding shaft; one end of the spring 7 is fixedly mounted on the mounting plate 3, and the other end is connected to the floating roller 2, and the movable end of the spring can be extended and retracted with the floating roller; the displacement sensor is fixedly mounted on the mounting plate 3, and its movable ring is connected to the spring. As the spring moves, the ring of the displacement sensor follows the movement to realize the measurement of the extension and retraction length of the spring.

[0025] Reference Figures 1 to 3 As shown, the roll diameter sensor 1 in this embodiment uses an ultrasonic sensor with a measurement accuracy of 0.1 mm. The roll diameter sensor is aligned with the unwinding shaft 3 in the measurement direction. After the carbon fiber raw material is installed on the unwinding shaft, the PLC calculates the roll diameter of the carbon fiber raw material according to the measurement value of the roll diameter sensor.

[0026] The floating roller 2 is used to balance the movement of the yarn path. A spring 7 is connected between the floating roller 2 and the mounting plate 3. The floating roller 2 floats under the action of the yarn path tension and the spring elastic force. The displacement sensor 8 is used to measure the stretching length of the spring 7. The PLC calculates the current tension value of the yarn path based on the measurement value of the displacement sensor.

[0027] According to the yarn path tension setting value and the yarn path tension measurement value, the PLC controller obtains the force that the unwinding shaft should output through PID calculation.

[0028] The output shaft of the servo integrated machine is directly connected to the unwinding shaft. Through the unwinding shaft diameter obtained above and the force that the unwinding shaft should output, the PLC calculates the torque that the servo integrated machine should output and sends the value to the servo integrated machine.

[0029] Embodiment 2:

[0030] Based on the above control system for automatic unwinding of a carbon fiber laying machine, the present application also provides a control method thereof, and the control method comprises the following steps: The distance between the roll diameter sensor and the unwinding shaft center is measured as L. According to the real-time measurement value a of the roll diameter sensor, the real-time roll diameter value d of the carbon fiber raw material is obtained as (La)*2; The spring coefficient is set to k, and the spring is in a free state when the floating roller is in the initial position. According to the displacement sensor measurement value b, the current tension value of the yarn path is obtained as f=b*k / 2; The preset value of the yarn path tension is set to X, and the PLC calculates the unwinding shaft output force F through the PID control algorithm according to the tension setting value X and the current tension value f of the yarn path.

[0031] Furthermore, the torque output by the unwinding shaft is M=F*d / 2.

[0032] 1. Measure the distance from the fixed ultrasonic sensor to the axis of the unwinding shaft as L. According to the real-time measurement of a by the ultrasonic sensor, the real-time value of the unwinding shaft diameter d=(La)*2 is obtained; 2. The selected spring coefficient is k. When the floating roller is in the initial position, the spring is in a free state. As the yarn path wraps around the floating roller, the current tension value of the yarn path is obtained according to the real-time measurement value b of the displacement sensor, f=d*k / 2; 3. The yarn path tension setting value is X. The PLC calculates the force F that the unwinding shaft should output based on the tension setting value X and the current value f through the PID control algorithm; 4. Considering that the output shaft of the servo integrated machine is directly connected to the unwinding shaft, the torque M=F*d / 2 that the servo integrated machine should output is obtained; 5. PLC sends the calculated torque value M to the servo integrated machine in real time, thereby realizing automatic unwinding control; 6. According to the fault diagnosis strategy, write a response program in the PLC controller. When the corresponding conditions are met, the PLC automatically determines the yarn path fault and realizes fault self-diagnosis.

[0033] Embodiment 3:

[0034] like Figure 4 As shown, the control scheme provided by this application also passes Figure 4 The strategy realizes the diagnosis of two faults: yarn path material shortage and yarn path material exhaustion. The process uses the detection result of the coil diameter sensor on the coil diameter of the carbon fiber raw material. When the coil diameter d>=a of the carbon fiber raw material, the equipment lays the yarn normally.

[0035] When the coil diameter d of the carbon fiber raw material is less than a, it enters the warning program for the carbon fiber wire material. When the coil diameter b of the carbon fiber raw material is less than d and less than a, the coil diameter sensor sends the coil diameter of the carbon fiber raw material to the PLC. The PLC alarms "The material is about to run out", the PLC controls the fiber placement machine to stop, and controls the safety clamping, and controls the tension system to stop.

[0036] Furthermore, when the coil diameter d of the carbon fiber raw material is less than b, the coil diameter sensor sends the coil diameter of the carbon fiber raw material to the PLC through the servo integrated machine. The PLC alarms "There is no material", and controls the fiber placement machine not to start working.

[0037] Example 4:

[0038] As Figure 5 shown, the control scheme provided by this application also realizes the diagnosis of yarn jamming faults through Figure 5 a strategy; this process detects the rotational speed of the servo integrated machine. After the yarn feeding step is completed, the rotational speed of the motor in the servo integrated machine is immediately detected. If the rotational speed is not less than the set value r1, normal fiber placement is carried out; If the motor rotational speed < r1, the PLC alarms "Yarn path is jammed", the equipment stops automatic fiber placement, and manual cleaning of the jammed yarn is carried out.

[0039] Example 5:

[0040] As Figure 6 shown, the control scheme provided by this application also realizes the diagnosis of yarn knotting faults through Figure 6 a strategy; this process monitors the measured value of the displacement sensor. During the fiber placement process of the fiber placement machine, the position information of the floating roller is obtained in real time. If the measured value of the displacement sensor =< the set value s1, continue normal fiber placement; If the measured value of the displacement sensor > the set value s1, the PLC alarms "Yarn path is knotted", the equipment stops automatic fiber placement, the tension system stops, and manual sorting of the yarn path and re-threading of the yarn are carried out.

[0041] Example: 6:

[0042] As Figure 7 shown, the control scheme provided by this application also realizes the diagnosis of yarn breakage faults through Figure 7 a strategy; this process monitors the measured value of the displacement sensor. During the fiber placement process of the fiber placement machine, the position information of the floating roller is obtained in real time. If the measured value of the yarn path displacement sensor >= the set value s2, continue normal fiber placement; If the measured value of the yarn path displacement sensor < the set value s2, the PLC alarms "Yarn path is broken", the equipment stops automatic fiber placement, the tension system stops, and manual sorting and re-threading are carried out.

[0043] Example 7:

[0044] As Figure 7 As shown, the control scheme provided by this application also passes Figure 8 The strategy realizes the fault diagnosis of yarn cutting failure. The process detects the rotation speed of the servo integrated machine. After the yarn cutting is completed, the rotation speed of the servo integrated machine is immediately detected. If the rotation speed is not greater than the set value r2, the yarn laying continues normally. If the motor speed > r2, the PLC alarm "yarn cutting failure" will be sounded, the equipment will stop automatic yarn laying, and the cause will be manually checked.

[0045] The present invention has many specific application paths. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A control method for a control system of an automatic unwinding of a carbon fiber laying machine, characterized in that: The control method comprises the following steps: The distance between the roll diameter sensor and the unwinding shaft center is measured as L. According to the real-time measurement value a of the roll diameter sensor, the real-time roll diameter value d of the carbon fiber raw material is obtained as (La)*2; The spring coefficient is set to k, and the spring is in a free state when the floating roller is in the initial position. According to the displacement sensor measurement value b, the current tension value of the yarn path is obtained as f=b*k / 2; The preset value of the yarn path tension is set to X, and the PLC calculates the unwinding shaft output force F through the PID control algorithm according to the tension setting value X and the current tension value f of the yarn path.

2. The control method of a control system for an automatic unwinding of a carbon fiber laying machine according to claim 1, characterized in that: The torque output by the unwinding shaft is M=F*d / 2.

3. The control method of a control system for an automatic unwinding of a carbon fiber laying machine according to claim 2, characterized in that: The control system comprises: A coil diameter sensor, the coil diameter sensor and the unwinding shaft are mounted on the same side of the mounting plate, the carbon fiber raw material is wound on the unwinding shaft, and the coil diameter sensor is used to detect the coil diameter of the carbon fiber raw material; A floating roller, the bottom end of which is mounted in a U-shaped groove of a mounting plate, with the roller body on the same side as the unwinding shaft, and the yarn path of the carbon fiber raw material wraps around the floating roller; a spring is provided at the connection between the floating roller and the mounting plate; A displacement sensor is installed beside the spring, a movable collar of the displacement sensor is connected to the end of the spring, and the displacement sensor is used to measure the stretched length of the spring; A servo integrated machine, wherein the output end of the servo integrated machine is directly connected to the unwinding shaft, and the servo integrated machine is used to control the unwinding torque. The PLC calculates the output torque of the unwinding shaft, that is, the output torque of the servo integrated machine, and sends it to the servo integrated machine.

4. The control method of a control system for an automatic unwinding of a carbon fiber laying machine according to claim 2, characterized in that: The bottom end of the floating roller is installed in a U-shaped groove in the installation plate, and the floating roller floats under the action of the yarn path tension and the spring elastic force.

5. The control method of a control system for an automatic unwinding of a carbon fiber laying machine according to claim 2, characterized in that: The position of the floating roller and the speed of the unwinding shaft are used to realize self-diagnosis of faults during the unwinding control process.

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