CN-121993557-A - Automatic belt tensioning system and method based on vibration frequency analysis

CN121993557ACN 121993557 ACN121993557 ACN 121993557ACN-121993557-A

Abstract

The application relates to the technical field of mechanical transmission control, in particular to an automatic belt tensioning system and method based on vibration frequency analysis, wherein the system comprises an excitation device, a transmission device and a transmission device, wherein the excitation device is used for applying transient mechanical excitation to a belt to excite the belt to vibrate freely; the belt tension control device comprises a non-contact sensor, a control unit, an excitation device, a frequency spectrum analysis device and an execution mechanism, wherein the non-contact sensor is used for collecting vibration signals generated by free vibration, the control unit is connected with the excitation device and the non-contact sensor and is configured to control the excitation device to act, the collected vibration signals are subjected to frequency spectrum analysis to extract vibration fundamental frequency of a belt, a real-time tension value of the belt is calculated according to the vibration fundamental frequency and pre-stored belt parameters, the real-time tension value is compared with a target tension value, and when deviation exceeds a preset dead zone threshold value, a control signal is generated based on a control algorithm, and the execution mechanism is connected with the control unit and is used for adjusting the center distance between two wheels for driving the belt according to the control signal to adjust the belt tension. The stable power output of the transmission system of the press is ensured.

Inventors

SONG HONGNING
WANG ZHIHUI
QU CHANGBING
XIE YONG
WANG KUNKUN

Assignees

济南二机床集团有限公司

Dates

Publication Date: 20260508
Application Date: 20251226

Claims (10)

1. An automatic belt tensioning system based on vibration frequency analysis, comprising: excitation means for applying a transient mechanical excitation to the belt to excite its free vibration; the non-contact sensor is used for collecting vibration signals generated by free vibration; a control unit connected to the excitation device and the non-contact sensor and configured to; controlling the actuation of the actuation means; The method comprises the steps of collecting vibration signals, carrying out frequency spectrum analysis on the collected vibration signals to extract vibration fundamental frequency of a belt, calculating real-time tension value of the belt according to the vibration fundamental frequency and pre-stored belt parameters, comparing the real-time tension value with a target tension value, and generating control signals based on a control algorithm when deviation exceeds a preset dead zone threshold value; And the actuating mechanism is connected with the control unit and is used for adjusting the center distance between two wheels of the driving belt according to the control signal so as to adjust the tension of the belt.
2. The automatic belt tensioning system based on vibration frequency analysis according to claim 1, wherein the excitation means comprises a pneumatic hammer, an air supply unit, and a pressure regulation unit; An air source supply unit for supplying compressed air; the pressure regulating unit comprises a pressure regulating valve and a high-speed electromagnetic valve; The high-speed electromagnetic valve is used for setting and stabilizing the working pressure which is transmitted to the pneumatic hammer, and is controlled by the control unit and used for controlling the on-off of compressed air to trigger the pneumatic hammer to act; The hammer head of the pneumatic hammer is aligned with the loose edge of the belt, and the knocking direction of the hammer head is perpendicular to the plane of the belt.
3. The automatic belt tensioning system based on vibration frequency analysis of claim 1, wherein the control unit is configured to extract the vibration fundamental frequency by: windowing pretreatment is carried out on the vibration signal; FFT is carried out on the preprocessed signals to obtain frequency spectrums, and the frequency spectrums are converted into amplitude spectrums or power spectrum density; and identifying local maximum points in a preset effective frequency range, and selecting peak frequency with the maximum amplitude and a signal-to-noise ratio higher than a threshold value as a fundamental frequency candidate value.
4. The automatic belt tensioning system based on vibration frequency analysis according to claim 1, wherein the actuator comprises a servo motor, a ball screw pair and a linear guide rail pair, an output shaft of the servo motor is connected with a screw of the ball screw pair through an elastic coupling, a nut of the ball screw pair is fixedly connected with a sliding plate, and the sliding plate is used for installing one of a driving motor or a flywheel and is supported and guided through the linear guide rail pair.
5. The automatic belt tensioning system based on vibration frequency analysis of claim 4, wherein the actuator varies the center-to-center distance by: the control unit controls the servo motor to rotate according to a set direction and an angle; The torque of the servo motor is transmitted through the elastic coupling to drive the screw rod of the ball screw pair to rotate; The rotation of the lead screw drives the nut meshed with the lead screw to generate linear motion; the nut drives the sliding plate fixedly connected with the nut to linearly move along the linear guide rail pair; The movement of the sliding plate drives a driving motor or a flywheel arranged on the sliding plate to move, so that the center distance between the driving motor and the flywheel is changed.
6. The automatic belt tensioning system based on vibration frequency analysis according to claim 1, wherein the control algorithm is a PID control algorithm, and the control unit is configured to perform the operation of the PID control algorithm only when the absolute value of the deviation exceeds the preset dead zone threshold.
7. The automatic belt tensioning system based on vibration frequency analysis according to claim 1, wherein the control unit pre-stores a belt line density And effective vibration length And is configured to according to the formula Calculating the real-time tension value, wherein Is the fundamental frequency of the vibration.
8. An automatic belt tensioning method based on vibration frequency analysis is characterized by comprising the following steps: Applying transient mechanical excitation to the belt by an excitation device to excite the belt to generate free vibration; Collecting vibration signals generated by the free vibration through a non-contact sensor; Performing frequency spectrum analysis on the vibration signal, extracting the vibration fundamental frequency of the belt, and calculating a real-time tension value of the belt according to the vibration fundamental frequency and pre-stored belt parameters; And comparing the real-time tension value with a target tension value, generating a control instruction based on a control algorithm when the deviation exceeds a preset dead zone threshold value, and driving an executing mechanism to change the tension of the belt by adjusting the center distance between two wheels driving the belt.
9. The automatic belt tensioning method based on vibration frequency analysis according to claim 8, wherein the step of performing a spectral analysis on the vibration signal, extracting a vibration fundamental frequency of the belt, and calculating a real-time tension value of the belt according to the vibration fundamental frequency and a pre-stored belt parameter comprises: windowing and removing trend items from the vibration signals; performing a fast fourier transform on the preprocessed signal to obtain a frequency spectrum; In the frequency spectrum, identifying fundamental frequency candidate values in a preset effective frequency range, and confirming the final vibration fundamental frequency by verifying whether harmonic components exist at integer frequency multiplication positions of the fundamental frequency candidate values; Using the formula Calculating a real-time tension value; Wherein, the In order to achieve a linear density of the belt, In order for the length of the vibration to be effective, Is the fundamental frequency of vibration.
10. The automatic belt tensioning method based on vibration frequency analysis according to claim 8, wherein in the step of driving the actuator to change the belt tension by adjusting the center distance between two wheels driving the belt, a servo motor is controlled to drive the ball screw pair to convert the rotational motion into the linear motion, thereby pushing the sliding plate carrying the motor or the flywheel to move along the linear guide rail to change the center distance.

Description

Automatic belt tensioning system and method based on vibration frequency analysis Technical Field The application relates to the technical field of mechanical transmission control, in particular to an automatic belt tensioning system and method based on vibration frequency analysis. Background The quick and efficient numerical control full-automatic stamping line is widely applied to the fields of automobile manufacturing and the like, a stamping machine is used as core equipment of a production line, and a transmission system of the stamping machine needs to have high reliability and stability. The transmission belt is used as a key component for transmitting power, and the accurate control of the tension of the transmission belt directly influences the operation efficiency and the service life of equipment. At present, two technical routes are mainly adopted for controlling belt tension between a motor and a flywheel of a press in the industry. One is to rely on manual periodic inspection and manual adjustment. The mode has obvious hysteresis, real-time response cannot be realized, the adjustment precision is influenced by experience of operators, and high requirements of modern automatic production lines on tension stability are difficult to meet. Another is to employ an automatic tensioning system based on tension sensors. Although the system realizes automatic adjustment, the tension sensor generally adopts a contact type measurement principle, and under severe working conditions such as high vibration, multiple dust and the like accompanied by the operation of a press, the abrasion, the drifting and even the damage are easy to occur, so that the measurement reliability is reduced, the maintenance cost is increased, and the long-term stability is difficult to ensure. Thus, prior art solutions still present challenges in achieving long-term stable, economical and reliable, and precise automatic control of press belt tension. Disclosure of Invention In order to solve the problems, the invention provides an automatic belt tensioning system and method based on vibration frequency analysis, which solve the problems of poor reliability and short service life of the traditional contact type tension sensor under the working condition. In a first aspect, the present invention provides an automatic belt tensioning system based on vibration frequency analysis, comprising: excitation means for applying a transient mechanical excitation to the belt to excite its free vibration; the non-contact sensor is used for collecting vibration signals generated by free vibration; a control unit connected to the excitation device and the non-contact sensor and configured to; controlling the actuation of the actuation means; The method comprises the steps of collecting vibration signals, carrying out frequency spectrum analysis on the collected vibration signals to extract vibration fundamental frequency of a belt, calculating real-time tension value of the belt according to the vibration fundamental frequency and pre-stored belt parameters, comparing the real-time tension value with a target tension value, and generating control signals based on a control algorithm when deviation exceeds a preset dead zone threshold value; And the actuating mechanism is connected with the control unit and is used for adjusting the center distance between two wheels of the driving belt according to the control signal so as to adjust the tension of the belt. As a further limitation of the technical scheme of the invention, the excitation device comprises a pneumatic hammer, an air source supply unit and a pressure regulation unit; An air source supply unit for supplying compressed air; the pressure regulating unit comprises a pressure regulating valve and a high-speed electromagnetic valve; The high-speed electromagnetic valve is used for setting and stabilizing the working pressure which is transmitted to the pneumatic hammer, and is controlled by the control unit and used for controlling the on-off of compressed air to trigger the pneumatic hammer to act; The hammer head of the pneumatic hammer is aligned with the loose edge of the belt, and the knocking direction of the hammer head is perpendicular to the plane of the belt. The air source supply unit is matched with the pressure regulating unit, so that the working pressure of the pneumatic hammer can be accurately set and stabilized, the consistency of knocking force each time is ensured, the influence of excitation intensity fluctuation on the effectiveness of vibration signals is avoided, and the repeatability and accuracy of tension measurement are improved. The high-speed electromagnetic valve has high response speed, can be accurately controlled by the control unit, realizes quick on-off of compressed air, enables the pneumatic hammer to generate transient and short knocking actions, efficiently excites the belt to vibrate freely, and can not cause continuous damage to the belt. The hig