CN-122016124-A - Electric screw driver operation quality on-line monitoring control system

Abstract

The invention relates to the technical field of torque control and discloses an online monitoring control system for the operation quality of an electric screwdriver, which comprises an electric screwdriver body, a multiparameter monitoring module, a data processing module, a prediction compensation module and an execution control module, wherein the electric screwdriver body is provided with a brushless direct current motor and a brake reducer, the multiparameter monitoring module is used for online collecting signals in the operation process of the electric screwdriver body, the data processing module is provided with a built-in pre-trained dynamic and static torque coupling model and used for receiving collected data of the multiparameter monitoring module and calculating offset and offset rate of dynamic torque and static torque, the prediction compensation module is used for generating torque compensation amount based on the calculation result of the dynamic and static torque coupling model, and the execution control module is used for carrying out real-time compensation on the output torque of the brushless direct current motor through a rotating speed and current double closed loop control strategy. The invention can improve the offset of dynamic moment and static moment in the prior art, realize the active preventive control of the static moment and improve the torque control precision of screw tightening assembly.

Inventors

• WANG FEI

Assignees

• 河北雄安诺亿通智能科技有限公司

Dates

Publication Date

20260512

Application Date

20260304

Claims (6)

1. 1. An electric screwdriver operation quality on-line monitoring control system, which is characterized by comprising: The electric screwdriver body is provided with a brushless direct current motor and a braking speed reducer and is used for executing screw tightening or disassembling operation; The multi-parameter monitoring module is used for collecting dynamic moment, motor current, motor temperature and material type signals of a connected piece in the operation process of the electric screwdriver body on line; The data processing module is internally provided with a pre-trained dynamic and static moment coupling model and is used for receiving the acquired data of the multi-parameter monitoring module and calculating the offset and the offset rate of the dynamic moment and the static moment; The prediction compensation module is used for predicting the static torque value of the screw after being screwed down in real time through a lightweight prediction algorithm based on the calculation result of the dynamic static torque coupling model to generate a torque compensation quantity; The execution control module is electrically connected with the brushless direct current motor and the braking speed reducer by adopting a rotating speed and current double closed-loop control strategy, and the output torque of the brushless direct current motor is compensated in real time by the rotating speed and current double closed-loop control strategy.
2. 2. The on-line monitoring and controlling system for the operation quality of the electric screwdriver according to claim 1, wherein the multi-parameter monitoring module 2 comprises: the sensor unit comprises a torque sensor, a current sensor, a temperature-sensitive resistor and a visual sensor, wherein the torque sensor is used for collecting dynamic torque signals in the operation process of the electric screw driver body, the current sensor is used for collecting real-time current signals in the operation process of the brushless direct current motor, the temperature-sensitive resistor is used for collecting real-time temperature signals in the operation process of the brushless direct current motor, and the visual sensor is used for collecting material type signals of a connected piece; The signal conditioning unit is used for filtering, amplifying and shaping the acquired dynamic moment signals, real-time current signals and real-time temperature signals to enable the processed signal amplitude to be matched with the input signal range of the data processing module, and the signal conditioning unit is electrically connected with the signal input end of the data processing module.
3. 3. The system according to claim 2, wherein the visual sensor determines a material type signal of the connected piece by collecting an appearance image feature of the connected piece, and maps the material type signal to a material hardness coefficient of the connected piece.
4. 4. The on-line monitoring and controlling system for the working quality of the electric screw driver according to claim 1, wherein the dynamic and static moment coupling model pre-trained in the data processing module 3 is obtained by: Collecting historical operation data, wherein the historical operation data comprise dynamic moment data, static moment actual measurement data, motor current change curves and operation temperature change data of screws with different specifications, different material types of connected pieces, different hardness coefficients of the connected pieces and electric screwdrivers in different operation temperature intervals; Preprocessing historical operation data, namely cleaning and normalizing the collected historical operation data, removing abnormal data, and dividing the processed data into a training set and a verification set; Training model parameters, namely training model parameters by using a training set through a supervised learning algorithm by taking a dynamic moment change rate, a motor current fluctuation value, an operation temperature gradient and a material hardness coefficient of the connected piece as input characteristics and static moment measured data as output labels, and establishing a mapping relation between the input characteristics and the static moment; optimizing the verification model, namely performing iterative optimization on the trained model by using the verification set until the error of the static torque predicted value of the verification set and the static torque measured data of the model is within a preset error range, and finishing pre-training; and the dynamic and static moment coupling model receives the acquired data of the multi-parameter monitoring module through the mapping relation, and calculates the offset of the current dynamic moment relative to the final static moment and the offset rate in unit time.
5. 5. The on-line monitoring control system for the operation quality of the electric screwdriver according to claim 1, wherein the lightweight prediction algorithm of the prediction compensation module 4 is an improved long-short-term memory network, and the model structure is simplified by cutting the number of hidden layers of the network and optimizing the type of an activation function, so that the embedded control environment of the electric screwdriver body is adapted; the lightweight prediction algorithm predicts the static torque value after screw tightening in real time based on the offset and the offset rate of the dynamic torque and the static torque output by the data processing module and combined with the torque attenuation characteristic of the connected piece material type and the connected piece material hardness coefficient.
6. 6. The on-line monitoring control system of the operation quality of the electric screwdriver according to claim 1, wherein the execution control module comprises: The overrun monitoring unit is used for receiving the moment compensation quantity instruction generated by the prediction compensation module, comparing the moment compensation quantity with a preset maximum compensation quantity adjusting range and judging whether to trigger cooperative braking; The rotating speed and current double closed-loop control unit comprises a rotating speed outer ring and a current inner ring, wherein the rotating speed outer ring is used for collecting the real-time rotating speed of the brushless direct current motor, and correcting the adjustment parameters of the current inner ring based on the difference value between the rotating speed and the target rotating speed; When the overrun monitoring unit judges that the moment compensation amount is within a preset range, the rotating speed and current double closed loop control unit only outputs a pulse width modulation duty ratio instruction, and adjusts the output moment of the brushless direct current motor; when the overrun monitoring unit judges that the moment compensation quantity exceeds the preset range, the execution control module synchronously sends a cooperative braking signal to the braking speed reducer, and drives the braking speed reducer to adjust braking force while limiting the upper limit of armature current of the brushless direct current motor.

Description

Electric screw driver operation quality on-line monitoring control system Technical Field The invention relates to the technical field of torque control, in particular to an on-line monitoring and controlling system for the operation quality of an electric screwdriver. Background The electric screw driver is used as a core tool for industrial assembly, the torque control precision of the electric screw driver directly determines the assembly quality, the structural stability and the service life of a product, and along with the improvement of the manufacturing industry to the precision, the automation and the intellectualization, the torque control of the electric screw driver is developed from pure standard stopping to higher-order demands. At present, the torque control technology of the electric screwdriver is mainly divided into two types, namely mechanical torque control and electric control torque control, wherein the mechanical torque control realizes automatic slip after reaching the torque standard through a mechanical clutch, has a simple structure but low precision and is easy to cause torque deviation due to mechanical abrasion, the electric control torque control is a current mainstream technology, signals such as current, rotating speed and dynamic torque of the electric screwdriver are collected through a sensor and are compared with a preset torque value after being processed by a main control module, the motor is controlled to stop rotating when the real-time torque reaches the standard, and part of the technologies can also realize online uploading and simple early warning of torque data, so that the control precision and the intelligent level are greatly improved compared with the mechanical technology. The existing electric control type torque control technology still has the following technical problems that the high-order requirement of precise assembly is difficult to meet: (1) Only the dynamic moment detection in the operation process is concerned, the offset problem between the dynamic moment and the static moment in the stable state after the screw is screwed is ignored, the dynamic moment reaches the standard in part of scenes, but the static moment exceeds the qualified range due to factors such as material characteristics, temperature change and the like, and the hidden trouble of assembly quality is caused; (2) In the prior art, most of torque adjustment is controlled passively when reaching standards, dynamic compensation strategies aiming at different stages of screw tightening are not available, and excessive loosening, excessive tightening or mechanical impact are easily caused by improper compensation time and amplitude; (3) The technology of double closed-loop control is adopted in part, only the rotation speed and current regulation of the motor are concerned, the cooperative matching of the control module and the braking speed reducer is not realized, and the problems of rotation speed fluctuation, moment response lag and the like are easy to occur in the torque compensation process. Disclosure of Invention The invention aims to solve the problems that in the prior art, offset between dynamic torque and static torque in a stable state after screwing is ignored, dynamic compensation strategies aiming at different stages of screwing are not adopted, and rotation speed fluctuation and torque response lag are easy to occur in a torque compensation process, and provides an on-line monitoring and controlling system for the operation quality of an electric screwdriver. In order to achieve the purpose, the invention adopts the following technical scheme that the on-line monitoring and controlling system for the operation quality of the electric screw driver comprises: The electric screwdriver body is provided with a brushless direct current motor and a braking speed reducer and is used for executing screw tightening or disassembling operation; The multi-parameter monitoring module is used for collecting dynamic moment, motor current, motor temperature and material type signals of a connected piece in the operation process of the electric screwdriver body on line; The data processing module is internally provided with a pre-trained dynamic and static moment coupling model and is used for receiving the acquired data of the multi-parameter monitoring module and calculating the offset and the offset rate of the dynamic moment and the static moment; The prediction compensation module is used for predicting the static torque value of the screw after being screwed down in real time through a lightweight prediction algorithm based on the calculation result of the dynamic static torque coupling model to generate a torque compensation quantity; The execution control module is electrically connected with the brushless direct current motor and the braking speed reducer by adopting a rotating speed and current double closed-loop control strategy, and the output torque of the brushless direc