Research On The Measurement Method Of Straightness Of Automobile Longitudinal Beam

The frame is a frame-shaped structural member that is bridged between the front and rear axles of the car,which is the installation base for each assembly and parts of the car.As a key component of the frame,the longitudinal beam directly affects the carrying capacity of the car.In actual production,the longitudinal beams often have problems such as wrinkles,arches,and warpage after processing and forming,resulting in straightness that does not meet the standards,which affects the assembly and bearing capacity of auto parts.In order to make the straightness of the stringer meet the requirements of the index,the straightness must be tested after its formation.At present,most factories use manual wire inspection method,which has low efficiency and low accuracy.Based on the current situation mentioned above,this subject takes automobile longitudinal beams as the research object,and designs and develops a set of straightness detection system for automobile floor longitudinal beams.This article first describes the current research status of straightness detection as well as the straightness detection methods and evaluation methods.Aiming at the problems of complicated time-consuming and low accuracy in the current manual wire drawing method,a fixed sampling method is proposed to realize the straightness measurement of the longitudinal beam.In this method,multiple displacement sensors are used to measure the longitudinal beam,and the straightness of the piece to be measured can be obtained by collecting,analyzing,and fitting the sampled data.According to the above methods,the detection system architectures of two data transmission methods,wired and wireless,are respectively established.The wired transmission architecture uses the sampling communication module and the data aggregation module as system hardware.The sampling data is aggregated through the CAN bus,and the C# software is used to develop the upper computer software to achieve communication and data processing with the lower computer.The wireless transmission architecture uses the sampling communication module and WIFI module as the system hardware,and realizes the sampling data aggregation through socket communication,and uses the back-end framework SSM and the front-end framework Bootstrap to develop the back-end server and front-end to achieve network communication,data processing,and man-machine interactive and other functions.Finally,the system is tested,and the accuracy of the system is calibrated in conjunction with a three-coordinate measuring instrument,and then the repeatability and reproducibility of the system are evaluated by the method of measurement system analysis.Experimental results show that the single measurement time of the system is about 3s,the accuracy reaches 0.1mm/m,and the repeatability and reproducibility are also ideal.Compared with the manual wire drawing method,the detection efficiency and measurement accuracy of the fixed sampling method have been significantly improved,which is of great significance to the auto companies to improve their competitiveness and sustainable development.