阅读说明：本技术 汽车车身铆接质量自动在线检测系统及检测方法 (Automatic online detection system and detection method for riveting quality of automobile body ) 是由 刘凉 邹恒毅 赵新华 陶建涛 戴腾达 宋会 史晨阳 冯建峰 蒲程 于 2021-05-26 设计创作，主要内容包括：本发明公开了一种汽车车身铆接质量自动在线检测系统及检测方法,检测方法为：S1、探测传感器获得各探测点位的反馈信号,即铆接板的铆接点状态信号；S2、基于EMD算法的希尔伯特-黄变换的方法处理铆接点状态信号并建立铆接点信息特征模型；S3、将铆接点信息特征模型输入至已完成训练的铆接故障神经网络识别模型中,得到汽车车身铆接故障类型；检测系统包括机器人模块、数据采集模块、同步控制模块、数据处理与特征提取模块和铆接检测模块：该检测系统及检测方法通过对铆接点处的缺陷信息进行特征提取与分析,来完成故障的自动识别,提高了车身铆接质量的检测效率和准确率,可用于大批量铆接车身的重复检验。(The invention discloses an automatic on-line detection system and a detection method for automobile body riveting quality, wherein the detection method comprises the following steps: s1, the detection sensor obtains feedback signals of all detection point positions, namely riveting point state signals of the riveting plate; s2, processing the riveting point state signal and establishing a riveting point information characteristic model by using a Hilbert-Huang transform method based on an EMD algorithm; s3, inputting the riveting point information characteristic model into the trained riveting fault neural network recognition model to obtain the automobile body riveting fault type; the detection system comprises a robot module, a data acquisition module, a synchronous control module, a data processing and feature extraction module and a riveting detection module: according to the detection system and the detection method, the automatic identification of the fault is completed by performing characteristic extraction and analysis on the defect information at the riveting point, the detection efficiency and the accuracy of the riveting quality of the automobile body are improved, and the detection system and the detection method can be used for repeated inspection of large-batch riveting automobile bodies.)

1. An automatic online detection method for automobile body riveting quality is characterized by comprising the following steps:

s1, the detection sensor continuously transmits voltage signals or current signals to the riveting plate along a detection path including all riveting points on the riveting plate at a constant interval distance in a mode that a detection plane of a probe of the detection sensor is always parallel to a tangent plane of the curved surface central point of the riveting plate corresponding to each detection point, so as to obtain feedback voltage signals or feedback current signals of each detection point, namely riveting point state signals of the riveting plate;

s2, processing the riveting point state signal collected in the step S1 to obtain a riveting point information characteristic model; the specific implementation steps are as follows:

1) performing EMD on the rivet joint state signal subjected to the filtering processing in the step S201 by adopting an EMD algorithm-based Hilbert-Huang transformation method to obtain Intrinsic Mode Functions (IMF) components of different scales, and performing Hilbert-Huang transformation on the Intrinsic Mode Functions (IMF) components of the scales to obtain a spectrogram corresponding to each sampling point and comprising Y voltage curves;

2) extracting an effective spectrogram at each rivet riveting point from the spectrogram obtained in the step S202 as riveting characteristic information of a single rivet, and taking the number of sampling points corresponding to each voltage curve on the effective spectrogram and the voltage amplitude corresponding to the sampling points, namely the curve sequence number-the number of sampling points-the voltage amplitude as riveting characteristic information; further, each rivet joint point correspondingly obtains a plurality of riveting characteristic information with different dimensions;

3) respectively extracting riveting characteristic information of M dimensions from a plurality of riveting characteristic information of different dimensions of each rivet riveting point to form an information characteristic model of the riveting point;

and S3, inputting the riveting point information characteristic model obtained in the step S2 into the trained riveting fault neural network recognition model to obtain the automobile body riveting fault type.

2. The automatic online detection method for automobile body riveting quality according to claim 1, characterized in that in step S2, filtering processing is further required to be performed on the riveting point state signal before step 1); the filtering processing method is a median average filtering method.

3. The automatic online detection method for the riveting quality of the automobile body according to claim 1, wherein in step S2, the value range of Y is 6-15.

4. The automatic online detection method for the riveting quality of the automobile body according to claim 1, wherein in step S2, the value range of M is 11-40.

5. The automatic online detection method for automobile body riveting quality according to claim 1, characterized in that the riveting failure neural network recognition model performs construction of a BP neural network structure according to the following two formulas:

wherein N represents the number of hidden layers, and N is 2-5; n is the number of hidden layer neurons, and the number n of each hidden layer neuron is 8 to 30; i is the number of input neurons, and the number of the input neurons is consistent with the dimension value of the riveting characteristic information; j is the number of neurons in the output layer, the number of neurons is X +1, and the number of neurons comprises X fault riveting states and a normal riveting state; k is the number of standard samples, and a is an integer of 0-10.

6. The automatic online detection method for automobile body riveting quality according to claim 5, wherein in step S3, the training method for the riveting fault neural network recognition model comprises the following steps: sequentially arranging riveting characteristic information of M dimensions according to a sequence, inputting the riveting characteristic information into corresponding neurons in a neural network, transmitting the processed riveting characteristic information to an output layer by using neurons of an input layer and neurons of a hidden layer, comparing the processed riveting characteristic information with an expected output value after the output layer obtains a recognition result, adjusting the weight and threshold of each neuron according to the gradient change value of the neural network through an error back propagation algorithm to train the neural network until the actual output value and the expected value of the neural network meet the error setting requirement, and finishing the training; in the training process, setting the initial population size to be 100, selecting 1000 maximum iteration times of a neural network, wherein the learning rate is 0.01-0.5, and the allowable error precision is 0.1%; the output calculation of the input layer of the neural network adopts a linear function, and the output calculation of other layers adopts a sigmoid activation function; the fitness function of the genetic algorithm adopts:

7. a detection system for realizing the automatic online detection method for the riveting quality of the automobile body as claimed in claim 1, which is characterized by comprising the following steps:

the robot module consists of a multi-degree-of-freedom robot mechanical arm and a motion control system with multiple motion tracks arranged inside; the motion control system is connected with each driving motor in the multi-degree-of-freedom robot mechanical arm, so that the tail end of the multi-degree-of-freedom mechanical arm moves according to a riveting point detection path planned by the motion control system; a tool clamp is arranged at the tail end of the multi-degree-of-freedom mechanical arm;

the data acquisition module consists of a detection sensor and a data acquisition device; specifically, the detection sensor is clamped by a tool clamp and moves to each riveting point on the vehicle body along with the tool clamp to acquire the state of the riveting point; the data acquisition device is connected with the detection sensor and used for receiving the riveting point state signal detected by the detection sensor;

one end of the synchronous control module is connected with the motion control system of the robot module, and the other end of the synchronous control module is connected with the detection sensor of the data acquisition module, and the synchronous control module is used for triggering the motion control system to drive the multi-freedom mechanical arm to move according to the riveting point detection path corresponding to the detected object and synchronously triggering the data acquisition module to acquire riveting state information;

the data processing and characteristic extracting module is connected with the data acquisition module and used for receiving riveting point state signals sent by the data acquisition module, sequentially performing signal filtering processing, frequency spectrogram conversion of each riveting point and multi-dimensional riveting characteristic information acquisition, and constructing to obtain a characteristic model of each riveting point information;

the riveting detection module is connected with the data processing and feature extraction module, and the information feature model of each riveting point is input into the riveting failure neural network recognition model to complete the failure state detection and recognition of each riveting point of the automobile body.

Technical Field

The invention relates to the technical field of new energy automobiles, in particular to an automatic online detection system and a detection method for automobile body riveting quality.

Background

According to survey, for a new energy automobile, the driving distance can be increased by 10% when the weight of the automobile is reduced by 100kg, the battery energy can be saved by 15% to 20%, the braking distance is reduced by 5%, and the service life of a tire is prolonged by 7%. The automobile is lightened, so that the safety of the automobile is greatly improved, and the requirements of energy conservation, environmental protection and pollution reduction in the current society are met, so that the light weight of the automobile becomes an important direction for the development of new energy automobiles.

An important approach to the weight reduction of automobiles is to use lightweight materials. And the aluminum alloy in the light material becomes the first material for the development and selection of the new energy automobile in light weight because of the characteristics of low density, high strength, good conductivity and the like. The all-aluminum body technology also becomes an important technology for the lightweight development of automobiles. However, the aluminum alloy has the characteristics of high heat conductivity, easy surface oxidation and the like, and the traditional resistance spot welding is very difficult to connect the all-aluminum or steel-aluminum hybrid vehicle body.

The riveting process, as a quick mechanical fastening connection, can be used to join two or more layers of homogeneous or heterogeneous sheets. Meanwhile, the riveting process has the advantages of simple process, high strength of a riveting object, low cost, easiness in fault detection and troubleshooting and the like, and is widely applied to connection between composite materials. The existing detection of the riveting quality of the new-energy all-aluminum vehicle body adopts a manual detection mode, so that the efficiency is low, the detection environment is limited, and meanwhile, the detection misjudgment rate is high due to the interference of human factors.

Disclosure of Invention

The invention aims to provide an automatic on-line detection system and a detection method for automobile body riveting quality, which solve the problem of high misjudgment rate of automobile riveting faults caused by human factors and the like.

Therefore, the technical scheme of the invention is as follows:

an automatic online detection method for automobile body riveting quality comprises the following steps:

s1, the detection sensor continuously transmits voltage signals or current signals to the riveting plate along a detection path including all riveting points on the riveting plate at a constant interval distance in a mode that a detection plane of a probe of the detection sensor is always parallel to a tangent plane of the curved surface central point of the riveting plate corresponding to each detection point, so as to obtain feedback voltage signals or feedback current signals of each detection point, namely riveting point state signals of the riveting plate;

the method comprises the steps that based on the fact that when rivet states of rivet joints are different (rivets are complete, rivets have gaps or rivets are partially missing), feedback voltage signals or feedback current signals obtained by transmitting voltage signals or current signals to the rivets in a feedback mode are different, and therefore the feedback voltage signals or the feedback current signals can effectively reflect the internal riveting states of the current rivets;

s2, processing the riveting point state signal collected in the step S1 to obtain a riveting point information characteristic model; the specific implementation steps are as follows:

1) performing EMD on the rivet joint state signal subjected to the filtering processing in the step S201 by adopting an EMD algorithm-based Hilbert-Huang transformation method to obtain intrinsic mode function IMF components of different scales, and performing Hilbert-Huang transformation on the intrinsic mode function IMF components of the scales to obtain a spectrogram, corresponding to each sampling point and comprising Y voltage curves;

2) extracting an effective spectrogram at each rivet riveting point from the spectrogram obtained in the step S202 as riveting characteristic information of a single rivet, and taking the number of sampling points corresponding to each voltage curve on the effective spectrogram and the voltage amplitude corresponding to the sampling points, namely 'curve serial number-sampling points-voltage amplitude', as riveting characteristic information; further, each rivet joint point correspondingly obtains a plurality of riveting characteristic information with different dimensions;

3) respectively extracting riveting characteristic information of M dimensions from each rivet riveting point to form an information characteristic model of the riveting point;

and S3, inputting the riveting point information characteristic model obtained in the step S2 into the trained riveting fault neural network recognition model to obtain the automobile body riveting fault type.

Further, in step S2, filtering the riveting point state signal is required before step 1); the filtering processing method is a median average filtering method.

The step is based on the existence of noise in the information acquisition process, the noise sources are inherent noises such as mechanical noise, shot noise and the like of the whole acquisition system, and the noises generally obey Gaussian distribution and belong to Gaussian noise; second, the noise such as pulse brought by active excitation signal; therefore, when filtering and denoising the acquired signals, a median average filtering method combining a linear algorithm and a nonlinear algorithm with good filtering effects on two types of noise is adopted;

further, in step S2, Y has a value range of 6 to 15.

Further, in step S2, the value range of M is 11 to 40.

Further, the riveting fault neural network identification model constructs a BP neural network structure according to the following two formulas:

wherein N represents the number of hidden layers, and N is 2-5; n is the number of neurons in the hidden layer, and the number n of neurons in each hidden layer is 8-30; i is the number of input neurons, and the number of the input neurons is consistent with the dimension value of the riveting characteristic information; j is the number of neurons in the output layer, the number of neurons is X +1, and the number of neurons comprises X fault riveting states and a normal riveting state; k is the number of standard samples, and a is an integer of 0-10.

Further, in step S3, the training method for the riveting fault neural network recognition model is:

sequentially arranging riveting characteristic information of M dimensions according to a sequence, inputting the riveting characteristic information into corresponding neurons in a neural network, transmitting the processed riveting characteristic information to an output layer by using neurons of an input layer and neurons of a hidden layer, comparing the processed riveting characteristic information with an expected output value after the output layer obtains a recognition result, adjusting the weight and threshold of each neuron according to the gradient change value of the neural network through an error back propagation algorithm to train the neural network until the actual output value and the expected value of the neural network meet the error setting requirement, and finishing the training;

in the training process, setting the initial population size to be 100, selecting 1000 maximum iteration times of a neural network, wherein the learning rate is 0.01-0.5, and the allowable error precision is 0.1%;

the output calculation of the input layer of the neural network adopts a linear function, and the output calculation of other layers adopts a sigmoid type activation function;

the fitness function of the genetic algorithm adopts:

a detection system for realizing the automatic online detection method for the riveting quality of the automobile body comprises the following steps:

the robot module consists of a multi-degree-of-freedom robot mechanical arm and a motion control system with multiple motion tracks arranged inside; the motion control system is connected with each driving motor in the multi-freedom-degree robot mechanical arm, so that the tail end of the multi-freedom-degree mechanical arm moves according to a riveting point detection path planned by the motion control system; a tool clamp is arranged at the tail end of the multi-degree-of-freedom mechanical arm;

the data acquisition module consists of a detection sensor and a data acquisition device; specifically, the detection sensor is clamped by a tool clamp and moves to each riveting point on the vehicle body along with the tool clamp to acquire the state of the riveting point; the data acquisition device is connected with the detection sensor and used for receiving the riveting point state signal detected by the detection sensor;

one end of the synchronous control module is connected with the motion control system of the robot module, and the other end of the synchronous control module is connected with the detection sensor of the data acquisition module, and the synchronous control module is used for triggering the motion control system to drive the multi-freedom mechanical arm to move according to the riveting point detection path corresponding to the detected object and synchronously triggering the data acquisition module to acquire riveting state information;

the data processing and characteristic extracting module is connected with the data acquisition module and used for receiving riveting point state signals sent by the data acquisition module, sequentially performing signal filtering processing, frequency spectrogram conversion of each riveting point and multi-dimensional riveting characteristic information acquisition, and constructing to obtain a characteristic model of each riveting point information;

the riveting detection module is connected with the data processing and feature extraction module, and the information feature model of each riveting point is input into the riveting failure neural network recognition model to complete the failure state detection and recognition of each riveting point of the automobile body.

Compared with the prior art, the automatic online detection system and the detection method for the riveting quality of the automobile body can effectively solve the problems of low manual detection efficiency and high detection misjudgment rate caused by human factors. The automatic identification of the fault is completed by carrying out feature extraction and analysis on the defect information at the riveting point, the detection efficiency and the accuracy of the riveting quality of the automobile body are improved, and the method can be used for repeated inspection of large-batch riveting automobile bodies.

Drawings

FIG. 1 is a flow chart of the automatic on-line detection method for riveting quality of an automobile body according to the present invention;

FIG. 2 is a schematic diagram of the detection mode of the detection sensor in the automatic online detection method for the riveting quality of the automobile body according to the invention;

fig. 3 is a wave spectrum diagram of the riveting plate, which is obtained from the feedback voltage signal or the feedback current signal of each detection point location and takes the point number as the abscissa and the voltage amplitude as the ordinate in the embodiment of the present invention;

FIG. 4(a) is a graph of the spectrum corresponding to the riveting point of the first rivet in an embodiment of the present invention;

FIG. 4(b) is a graph of the spectrum corresponding to the riveting point of a second rivet in an embodiment of the present invention;

FIG. 4(c) is a graph showing a spectrum of a third rivet at a riveting point of a third rivet in an embodiment of the present invention;

FIG. 4(d) is a graph showing a spectrum of a riveting point of a fourth rivet in accordance with an embodiment of the present invention;

FIG. 5(a) is a schematic illustration of a rivet configured in an embodiment of the present invention with a missing end failure condition;

FIG. 5(b) is a schematic illustration of a rivet configured in an embodiment of the present invention with an in-line notch fault condition;

FIG. 5(c) is a schematic illustration of a rivet configured in an embodiment of the present invention with a cruciform notch fault condition;

FIG. 5(d) is a schematic view of a rivet configured in accordance with an embodiment of the present invention with a missing shank fault condition of 1/2 and above;

FIG. 6 is a schematic structural diagram of an automatic on-line detection system for riveting quality of an automobile body according to the present invention.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, which are not intended to limit the invention in any way.

Example 1

The automatic online detection method for the riveting quality of the automobile body is adopted to detect the riveting quality of one automobile body of a certain automobile; the automobile body plate is a plate with a curved surface formed by riveting three layers of stacked 8mm metal plates, and the total number of the plate is five.

As shown in fig. 1, the detection method comprises the following steps:

s1, acquiring riveting point state signals of the riveting plate by using the detection sensor;

specifically, as shown in fig. 2, the detection sensor continuously transmits a voltage signal to the riveting plate along a detection path including all riveting points on the riveting plate at a constant interval in a manner that a detection plane of a probe of the detection sensor is always parallel to a tangent plane of each detection point corresponding to a center point of the curved surface of the riveting plate, so as to obtain a feedback voltage signal of each detection point, that is, a riveting point state signal of the riveting plate.

Wherein, the detection plane of the detection sensor probe and the tangent plane of each detection point position corresponding to the curved surface central point of the riveting plate should satisfy the following interval distance: and the feedback voltage signal or the feedback current signal of each detection point reaches the subsequent data processing requirement.

Fig. 3 shows a wave spectrum diagram of the riveting plate, which is obtained by using the number of points as the abscissa and the voltage amplitude as the ordinate, with the feedback voltage signal or the feedback current signal of each detection point.

S2, processing the riveting point state signal collected in the step S1 to obtain a riveting point information characteristic model;

specifically, the specific implementation steps of step S2 are:

s201, filtering the riveting point state signal in a median average filtering method to remove inherent noise and pulse noise;

s202, EMD decomposition is carried out on the riveting point state signal after filtering processing in the step S201 by adopting a Hilbert-Huang transformation method based on an EMD algorithm to obtain intrinsic mode functions IMF components of different scales, and then Hilbert-Huang transformation is carried out on the intrinsic mode functions IMF components of all scales to obtain a spectrogram, corresponding to each sampling point, and containing 6 voltage curves;

s203, extracting effective spectrograms at riveting points of each rivet from the spectrograms obtained in the step S202 to serve as riveting characteristic information of a single rivet, and taking the sampling point number corresponding to each voltage curve on the effective spectrograms and the voltage amplitude value corresponding to the sampling point number, namely the curve serial number, the sampling point number and the voltage amplitude value as riveting characteristic information; further, each rivet joint point correspondingly obtains a plurality of riveting characteristic information with different dimensions;

FIG. 4(a) shows a spectrogram corresponding to a riveting point of a first rivet; FIG. 4(b) shows a spectrum diagram corresponding to the riveting point of the second rivet; FIG. 4(c) shows a spectrum diagram corresponding to the riveting point of the third rivet; fig. 4(d) shows a spectrum diagram corresponding to the riveting point of the fourth rivet.

S204, respectively extracting riveting characteristic information of M dimensions from each rivet riveting point to form an information characteristic model of the riveting point;

in this embodiment, the extracting of the riveting characteristic information of 11 dimensions for each rivet-riveting point includes: 6 peak heights for the 6 characteristic curves, and 5 deviation values generated between the peak heights. It should be noted that the selection of the riveting characteristic information amount is not fixed, and may be adjusted according to the requirement of the size degree of the identified fault defect, for example, if the requirement of the identification rate of the fine fault is high, the dimension amount of the riveting characteristic information should be increased.

And S3, inputting the riveting point information characteristic model obtained in the step S2 into the trained riveting fault neural network recognition model to obtain the automobile body riveting fault type.

Specifically, the riveting failure neural network recognition model adopts a feedforward neural network based on a genetic algorithm, a structural model of a multilayer neural network is set, the number of neurons in a hidden layer is optimized, a riveting point information characteristic model is used as input information, and riveting failure results of different types are used as output information, so that the recognition of failure characteristics is completed.

The riveting fault neural network identification model carries out the construction of a BP neural network structure according to the following two formulas:

wherein, N represents the number of hidden layers, and N is 2; n is the number of hidden layer neurons, the number n of the first hidden layer neurons is 14, and the number n of the second hidden layer neurons is 10; i is the number of input neurons, and the number thereof is M (i.e., the riveting characteristic information of M dimensions extracted in step S2); j is the number of output layer nerve cells, the number of which is 4, and the output layer nerve cells comprise three fault riveting states and a normal riveting state; k is the number of standard samples, and a is an integer of 0-10;

specifically, in this embodiment, the three faulty riveting states specifically include: the rivet shown in fig. 5(a) has an end missing fault, the rivet shown in fig. 5(b) or 5(c) has a straight notch fault or a cross notch fault, and the rivet shown in fig. 5(d) has a shank axial breakage fault; correspondingly, the normal riveting state, i.e., the rivet, does not have the above-described three failures.

The training method of the riveting fault neural network recognition model comprises the following steps:

optimizing the initial weight and the threshold of the riveting fault neural network model by adopting a genetic algorithm; specifically, according to three riveting fault types and one normal type set in the embodiment, 200 groups of detection samples which are consistent with the set type and have uniformly distributed types are selected as training samples and input into a neural network for training; each group of detection samples comprises M-dimensional riveting characteristic information corresponding to rivets, and the number and the arrangement sequence of the M-dimensional riveting characteristics are respectively in one-to-one correspondence with the number I and the arrangement sequence of the input neurons constructed by the model;

in the training process, setting the initial population scale to be 100, selecting 1000 maximum iteration times of a neural network, wherein the learning rate is 0.01-0.5, and the allowable error precision is 0.1%;

setting the fitness function of the genetic algorithm as follows:

the fitness function value is the reciprocal of the sum of squares of errors, and the optimal value of the parameter of the riveting fault neural network identification model is searched by using an improved self-adaptive gradient descent method; and setting the optimized initial weight and threshold values as corresponding parameters of the riveting fault neural network recognition model, selecting a linear function and a sigmoid activation function to calculate the output of each layer of the neural network, and performing learning training of the neural network according to the detection information.

In the specific training process, riveting characteristic information of M dimensions is sequentially arranged according to the sequence and is input into corresponding neurons in the neural network, processed riveting characteristic information is transmitted to an output layer by neurons of an input layer and neurons of a hidden layer, the output layer obtains a recognition result and then compares the recognition result with an expected output value, then the weight and threshold values of the neurons are adjusted through an error back propagation algorithm according to the gradient change value of the neural network to train the neural network until the actual output value and the expected value of the neural network meet the error setting requirement, and training is completed. And then verifying the detection result by using 100 groups of riveting test samples, wherein the detection success rate is 100%.

In this embodiment, in step S3, the riveting state of four riveting points corresponding to the four-amplitude spectrum obtained in step S2 is determined. Specifically, the riveting state output result of the first rivet-riveting point corresponding to fig. 4(a) is normal, the riveting state output result of the second rivet-riveting point corresponding to fig. 4(b) is that the end of the rivet is missing, the riveting state output result of the third rivet-riveting point corresponding to fig. 4(c) is that the rivet is axially broken, and the riveting state output result of the fourth rivet-riveting point corresponding to fig. 4(d) is that the rivet has a straight-line or cross-shaped notch fault.

Example 2

As shown in fig. 6, the automatic online detection system for automobile body riveting quality comprises a robot module, a data acquisition module, a synchronous control module, a data processing and feature extraction module and a riveting detection module; wherein the content of the first and second substances,

the robot module comprises a multi-degree-of-freedom robot mechanical arm and a motion control system with multiple motion tracks arranged inside; the motion control system is connected with each driving motor in the multi-degree-of-freedom robot mechanical arm, so that the tail end of the multi-degree-of-freedom mechanical arm moves according to a riveting point detection path planned by the motion control system; a tool clamp is arranged at the tail end of the multi-degree-of-freedom mechanical arm and used for clamping the detection sensor;

in the specific implementation process, a motion control system of the robot module selects a proper motion track to detect each riveting point on the vehicle body according to the specification of the vehicle body to be detected and the detection task requirement corresponding to the riveting process, so that the tail end of the multi-degree-of-freedom mechanical arm is sequentially detected at a proper detection distance to obtain a voltage feedback signal or a current feedback signal of each riveting point;

the data acquisition module comprises a detection sensor and a data acquisition device; in particular, the amount of the solvent to be used,

the detection sensor is clamped by the tool clamp and moves to each riveting point on the vehicle body along with the tool clamp to acquire the state of the riveting point; the working principle is as follows: when the riveting point of the vehicle body has the defect forms of fracture, crack and the like or the riveting form is changed, the voltage feedback signal or the current feedback signal received by the detection sensor is changed, and the changes are used as the technical basis for identifying the normal riveting state and the fault riveting state;

the data acquisition device is connected with the detection sensor and is used for receiving riveting point state signals detected by the detection sensor, namely voltage feedback signals or current feedback signals;

one end of the synchronous control module is connected with the motion control system of the robot module, and the other end of the synchronous control module is connected with the detection sensor of the data acquisition module, and the synchronous control module is used for triggering the motion control system to drive the multi-freedom mechanical arm to move according to the riveting point detection path corresponding to the detected object and synchronously triggering the data acquisition module to acquire riveting state information; specifically, the synchronous control module synchronously triggers the motion control system and the data acquisition module based on the I/O pulse signal;

the data processing and characteristic extracting module is connected with the data acquisition module and used for receiving riveting point state signals sent by the data acquisition module, sequentially performing signal filtering processing, frequency spectrogram conversion of each riveting point and multi-dimensional riveting characteristic information acquisition, and constructing to obtain a characteristic model of each riveting point information;

the riveting detection module is connected with the data processing and feature extraction module, and the information feature model of each riveting point is input into the riveting failure neural network recognition model to complete the failure state detection and recognition of each riveting point of the automobile body.

The embodiments of the invention disclosed above are intended to be merely illustrative of the invention. The embodiments of the invention are not described in detail, nor are they intended to limit the invention to the specific embodiments described. Any person skilled in the art should be able to cover all modifications and alterations within the scope of the present invention.