Tension active-disturbance-rejection fast-response control device and method for automatic joint robot

Abstract

The invention discloses an automatic joint robot tension active-disturbance-rejection fast response control device and method, and the device is characterized in that the device comprises a robot, a tension sensing device, a variable tension device and an electric control device, and the electric control device operates an algorithm based on active-disturbance-rejection control. Sensing of weak tension is established through a spring and lever model, and yarn breakage in the spun yarn splicing process can be effectively prevented. The two-section spun yarn tension control device can meet the tension requirements of different stages of spun yarn splicing, and the splicing success rate is increased. The force control performance is improved by adopting an active disturbance rejection control algorithm, and the stability of force tracking is improved by designing instruction filtering and an adaptive gain algorithm. The tension control stability in the automatic jointing process can be effectively improved, and the jointing success rate is increased.

Description

Technical Field

[0001] The invention relates to a tension self-disturbance rejection fast response control device and method for an automatic jointing robot, belonging to the technical field of automatic yarn jointing devices. Background Art

[0002] Spinning is an important pillar industry for people's livelihood in my country. Ring spinning is the mainstream process of spinning production. The total installed capacity of ring spinning accounts for more than 75% of the total number of spinning equipment. The high-end spun yarn produced by it is an important basic material related to the national economy and people's livelihood, national defense construction and major scientific projects. However, yarn breakage in the ring spinning process will cause the entire spinning process to be interrupted, and skilled workers are required to manually complete the joint. Realizing the automatic jointing of broken yarn in ring spinning is one of the important goals that the textile industry has always pursued. Driven by the demand for automatic jointing robots in the spinning industry and the development of technology, relatively mature automatic jointing technologies and devices have been developed both at home and abroad.

[0003] Since the success rate of finding the end of a broken yarn tube is low, the existing joint method mainly uses auxiliary yarn starting, such as the "A Ring Spinning Machine Automatic Joint Method" designed by the Chinese patent with the publication number CN112111817A, the "Ring Spinning Machine Broken End Automatic Intelligent Joint Method and Device" designed by the Chinese patent with the publication number CN105019077A, and the "A Ring Spinning Machine Automatic Joint Device and Method" designed by the Chinese patent with the publication number CN113174668A. All of them use spare yarn to wind on the broken yarn tube, and then pull the spare yarn through the wire ring, the balloon ring, the yarn guide hook and feed it into the front roller through the yarn drawing device. In the existing automatic jointing process, the control of the yarn tension is an important indicator parameter for the success rate of the joint.

[0004] In the automatic piecing process, the yarn tension mainly comes from two aspects: one is the traction force of the robot on the yarn, and the other is the tension generated by the winding and unwinding of the auxiliary yarn bobbin. Since the movement of the robot during the piecing process is fixed and cannot be changed, the control of the yarn tension mainly depends on the control of the winding and unwinding of the auxiliary yarn bobbin. By controlling the winding and unwinding speed of the auxiliary yarn bobbin, effective yarn tension control can be achieved, thereby ensuring that the yarn tension during the piecing process is within an appropriate range. Due to the interference of internal uncertainties and external factors such as the characteristics of the yarn, environmental factors, and the motion characteristics of the robot, the yarn tension will be disturbed. Exceeding the strong force of the yarn will cause the yarn to break and the piecing to fail. At the same time, in order to improve the efficiency of the piecing, the yarn tension control system needs to be able to respond quickly. Summary of the invention

[0005] The purpose of the invention is to quickly adjust the yarn tension to prevent the yarn from breaking during the automatic yarn jointing process, and effectively improve the jointing success rate and speed.

[0006] In order to achieve the above-mentioned purpose, one aspect of the technical solution of the present invention provides a tension self-anti-disturbance fast response control device for an automatic joint robot, characterized in that it includes a tension rod, the tension rod is arranged on an angle sensor, and the tension rod can swing around a hinge point, and the deflection of the tension rod is obtained in real time by the angle sensor, and the angle sensor uploads the obtained deflection angle to a controller; one end of the tension spring 1 and the tension spring 2 are connected and fixed to the tension rod, the other end of the tension spring 1 is fixed, and the other end of the tension spring 2 is connected to the output end of the pen-shaped cylinder 1; the output end of the pen-shaped cylinder 2 is provided with a yarn guide hook, After the yarn is freely driven by the servo motor to rotate the yarn tube, it passes through the yarn guide hook and then through the end of the tension rod. The tension rod applies tension to the yarn passing thereon through tension spring 1 and tension spring 2. Pen-shaped cylinder 1 drives tension spring 1 to amplify the overall tension and provide tension for yarn traction. Pen-shaped cylinder 2 drives the yarn guide hook to change the yarn path to achieve zero tension control. The controller runs a control algorithm with tension self-anti-disturbance fast response. The control algorithm controls the servo motor to wind up and unwind the spare yarn based on the obtained deflection angle to achieve tension control, so that the tension on the yarn is kept near the desired tension.

[0007] Another aspect of the technical solution of the present invention is to disclose a tension self-disturbance rejection fast response control method for an automatic joint robot, using the above-mentioned tension self-disturbance rejection fast response control device for an automatic joint robot, characterized in that the method comprises the following steps:

[0008] S1. Establish the controlled object model of the spinning tension control system, as shown in the following formula:

[0009]

[0010] Where y is the tension value, f is the total disturbance, u is the actual speed of the motor, and b0 is the gain of the control input;

[0011] S2. The controlled object model of the spinning tension control system is organized into the form of a third-order differential equation, and a third-order extended state observer is designed to observe the disturbance of the system. The third-order extended state observer is shown in the following formula:

[0012]

[0013]

[0014] Where z1, z2, z3, z4 are the observed values ​​of states x1, x2, x3, x4, ω0 is the bandwidth of the observer, and n is the order of the controlled object;

[0015] S3. Design a linear control rate for the lumped disturbance observed by the extended state observer to achieve tension control, where the control rate of the system is expressed as:

[0016]

[0017]

[0018] In the formula, w c is the bandwidth of the controller, a i is the gain of feedback;

[0019] S4. To address the tension overshoot caused by fast response, a command filter is designed. To address the sensor noise amplification problem caused by high-order ESO, an adaptive ESO gain is designed to obtain the final tension self-disturbance rejection fast response control rate.

[0020] Preferably, in step S4, the adaptive ESO gain tension self-disturbance rejection fast response control is expressed as follows:

[0021]

[0022]

[0023] e=gain×abs(r(t)-y(t)),

[0024]

[0025] ω y =[0-c r ]z+u,

[0026]

[0027] Where gain is the variable gain, c r is the filter bandwidth, upper is the upper bandwidth limit, lower is the lower bandwidth limit, z is the system state, ω x is the controller bandwidth with upper and lower limits, ω y is the bandwidth of the controller after filtering.

[0028] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0029] (1) The present invention adopts self-disturbance rejection control to realize the tension stabilization tracking control of the automatic spinning joint, so that the yarn tension is kept near the desired tension during the jointing process of the robot. The present invention can effectively prevent the yarn from breaking during the automatic spinning jointing process.

[0030] (2) The present invention provides a two-stage tension and zero tension solution, which is achieved by two pen-shaped cylinders. Before the automatic joint begins, the tension is controlled by a single spring, and a single spring provides a small tension to achieve smooth wire feeding of the joint robot and leave the yarn end. The second stage of tension is achieved by pulling the tension spring by the pen-shaped cylinder. The tension at this time satisfies the normal yarn traction of the joint robot, ensuring that the yarn is not tangled or broken.

[0031] (3) The second pen-shaped cylinder pulls the yarn guide hook to the center of the yarn tube, thereby changing the yarn path and making the tension control completely ineffective. At this time, the requirements of high-speed spinning of spare yarn airflow winding can be met.

[0032] The present invention provides an automatic joint robot tension control solution based on anti-disturbance control, which realizes stable tracking of tension through an anti-disturbance control algorithm, completes different tension controls required in the joint process through a pen-shaped cylinder and a tension spring, and improves the joint success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A control algorithm block diagram for the implementation of the present invention;

[0034] Figure 2 The mechanical structure diagram of the present invention is implemented. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0036] One aspect of the embodiment of the present invention is to provide a tension control device for an automatic joint robot based on self-disturbance rejection control, including a tension rod 101, a tension spring 102, a pen-shaped cylinder 103, a tension spring 104, an angle sensor 105, a pen-shaped cylinder 106, a bobbin 107, a servo motor 108, a yarn 109, and a controller. After the yarn 109 is drawn out from the bobbin 107, it passes through the tension rod 101 via a yarn guide hook, and the tension rod 101 is fixed on the angle sensor 105. The tension rod 101 applies tension to the yarn 109 passing thereon through the tension springs 102 and 104. In the embodiment of the present invention, two-stage tension and zero tension control are completed by the pen-shaped cylinders 103 and 106, wherein the pen-shaped cylinder 103 drives the tension springs 102 and 104 to amplify the overall tension and provide tension for yarn traction. The pen-shaped cylinder 106 drives the yarn guide hook to change the yarn path to achieve zero tension control to meet the tension requirements of the high-speed spinning of the spare yarn airflow. During the entire process of automatic jointing of ring spinning yarn, the deflection of the tension rod 101 is obtained in real time by the angle sensor 105 as the tension of the yarn 109, and uploaded to the controller. The controller runs a control algorithm with tension self-anti-disturbance fast response. The control algorithm controls the motor to reel in and out the spare yarn to achieve tension control, so that the tension on the yarn is kept near the desired tension.

[0037] In the implementation of the present invention, the angle sensor 105 uses a 0-5V analog angle encoder, and the controller uses an STM32F407 processor to achieve real-time processing and feedback of data.

[0038] Another aspect of an embodiment of the present invention is to provide an automatic joint tension control method based on self-disturbance rejection control. First, by analyzing the automatic joint tension control system and deducing the mathematical model of the yarn tension control system, a controlled object model of the yarn tension control system is established. Secondly, in order to improve the anti-interference ability of the system, a third-order extended state observer (ESO) is designed to observe system disturbances. Then, a command filter is designed to address the tension overshoot caused by fast response. Finally, in order to address the sensor noise amplification problem caused by high-order ESO, an adaptive ESO gain is designed to obtain the final tension self-disturbance rejection fast response control rate, which is finally applied to the controller to adjust the yarn tension in real time.

[0039] After receiving the desired tension, the controller obtains the actual angle of the tension rod 101 and the speed required by the tension motor through the mechanical model. The controller sends the speed to the motor drive so that the motor moves to the specified position and completes the position control of the tension rod 101, thereby indirectly controlling the yarn tension during the joint process to remain near the desired tension value, and preventing the failure of the joint caused by the breakage of the yarn during the joint process. In this process, the controller adjusts the dynamic and steady-state tension tracking performance of the tension control model when the environment changes by introducing the tension self-disturbance rejection fast response control algorithm. In an embodiment of the present invention, the controller runs an algorithm based on self-disturbance rejection control and a servo motor control algorithm based on PID control. After the controller receives the angle signal, the self-disturbance rejection control algorithm obtains the kinematic parameters of the servo motor 108, and sends the parameters to the servo motor control algorithm, so that the servo motor 108 reaches the specified speed and the tension rod 101 reaches the specified angle, thereby indirectly controlling the yarn tension during the joint process to remain near the desired tension value.

[0040] An automatic joint robot tension control method based on active disturbance rejection control disclosed in an embodiment of the present invention specifically comprises the following steps:

[0041] S1. Establish the controlled object model of the spinning tension control system.

[0042] In step S1, the yarn tension is T, the length of the tension rod is R0, the angle of the tension rod is q, the length of the spring 102 fixed rod is R3, the distance of the spring fixed rod from the far point is R2, the angle of the spring fixed rod is q0, the spring elastic coefficient is k, and the original length of the spring is L0. According to the lever principle and Hooke's law, the expression of tension can be obtained as follows:

[0043]

[0044] Wherein, θ is the deflection angle of the tension rod 101, and θ0 is the deflection angle of the fixing rod of the tension spring 102 relative to the center of the angle sensor 105.

[0045] The dynamic equation for tension control is:

[0046]

[0047] Wherein, the angles of the tension rod are θ1 and θ2 corresponding to the initial zero tension state and the belt tension state, the position of the wire loop 110 is (x1, y1), (x2, y2), and the speed of the motor 108 is v motor The speed of the external force pulling the yarn 109 is v env , v = v notor -v env .

[0048] Through parameter identification, a simplified second-order model of the motor can be obtained, as described in the following formula:

[0049]

[0050] Where s represents the system state.

[0051] The third-order model of the controlled object can be obtained from equations (2) and (3):

[0052]

[0053] Where y is the input (tension value), f is regarded as the total disturbance (including internal disturbance and external disturbance, the external disturbance is the speed of the yarn changed by the yarn traction effect), u is the actual speed of the motor, and b0 is the gain of the control input.

[0054] S2. The controlled object model of the spinning tension control system is organized into the form of a third-order differential equation, and a third-order extended state observer is designed to observe the disturbance of the system.

[0055] In step S2, in order to improve the anti-interference ability of the spinning tension system, a third-order extended state observer is designed, as shown in the following formula:

[0056]

[0057]

[0058] Where z1, z2, z3, z4 are the observed values ​​of states x1, x2, x3, x4, ω0 is the observer bandwidth, and n is the order of the controlled object.

[0059] S3. Design a linear error feedback control rate to achieve tension control based on the disturbance observed by the S2 extended state observer.

[0060] In step S3, define ω c is the controller bandwidth, ω0 is the observer bandwidth, according to the bandwidth tuning theory, ω0=3ω c , the control rate of the system is expressed as:

[0061]

[0062]

[0063] In the formula, w c is the bandwidth of the controller, a i is the feedback gain.

[0064] S4. To address the tension overshoot caused by fast response, a command filter is designed. To address the sensor noise amplification problem caused by high-order ESO, an adaptive ESO gain is designed to obtain the final tension self-disturbance rejection fast response control rate.

[0065] In step S4, gain is defined as a variable gain, c r is the filter bandwidth, upper is the upper bandwidth limit, and lower is the lower bandwidth limit. The adaptive ESO gain tension self-disturbance rejection fast response control involved is expressed as follows:

[0066]

[0067]

[0068] e=gain×abs(r(t)-y(t)),

[0069]

[0070] ω y =[0-c r ]z+u,

[0071]

[0072] In the formula, z is the system state, ω x is the controller bandwidth with upper and lower limits, ω y is the bandwidth of the controller after filtering.

Claims

1. A tension self-disturbance rejection fast response control device for an automatic joint robot, characterized in that: The utility model comprises a tension rod, which is arranged on an angle sensor and can swing around a hinge point, and the deflection of the tension rod is obtained in real time through the angle sensor, and the angle sensor uploads the obtained deflection angle to a controller; one end of a tension spring 1 and a tension spring 2 are connected and fixed to the tension rod, the other end of the tension spring 1 is fixed, and the other end of the tension spring 2 is connected to the output end of a pen-shaped cylinder 1; a yarn guide hook is arranged at the output end of the pen-shaped cylinder 2, and the yarn is freely driven by a servo motor to rotate the yarn tube, and then passes through the yarn guide hook and the end of the tension rod, and the tension rod applies tension to the yarn passing thereon through the tension spring 1 and the tension spring 2; the pen-shaped cylinder 1 drives the tension spring 1 to realize the amplification of the overall tension and provide tension for the yarn traction, and the pen-shaped cylinder 2 drives the yarn guide hook to change the yarn path to realize zero tension control; the controller runs a control algorithm with tension self-anti-disturbance fast response, and the control algorithm controls the servo motor to wind up and unwind the spare yarn based on the obtained deflection angle to realize tension control, so that the tension on the yarn is kept near the desired tension.

2. A tension self-disturbance rejection fast response control method for an automatic joint robot, using the tension self-disturbance rejection fast response control device for an automatic joint robot according to claim 1, characterized in that: The method comprises the following steps: S1. Establish the controlled object model of the spinning tension control system, as shown in the following formula: Where y is the tension value, f is the total disturbance, u is the actual speed of the motor, and b0 is the gain of the control input; S2. The controlled object model of the spinning tension control system is organized into the form of a third-order differential equation, and a third-order extended state observer is designed to observe the disturbance of the system. The third-order extended state observer is shown as follows: Where z1, z2, z3, z4 are the observed values ​​of states x1, x2, x3, x4, ω0 is the bandwidth of the observer, and n is the order of the controlled object; S3. Design a linear control rate for the system after disturbance compensation to achieve tension control, where the control rate of the system is expressed as: In the formula, w c is the bandwidth of the controller, a i is the feedback gain; S4. To address the tension overshoot caused by fast response, a command filter is designed. To address the sensor noise amplification problem caused by high-order ESO, an adaptive ESO gain is designed to obtain the final tension self-anti-disturbance fast response control rate.

3. The method for controlling the tension of an automatic joint robot with a fast response according to claim 2, characterized in that: In step S4, the adaptive ESO gain tension anti-disturbance fast response control is expressed as follows: e=gain×abs(r(t)-y(t)), ω y =[0-c r ]z+u, Where gain is the variable gain, c r is the filter bandwidth, upper is the upper bandwidth limit, lower is the lower bandwidth limit, z is the system state, ω x is the controller bandwidth with upper and lower limits, ω y is the bandwidth of the controller after filtering.

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