The Design Of Non-contact Laser Surface Roughness Instrument

Road roughness is the main factor causing the vehicle vibration. It has a direct impact on the vehicle’s drivetrain natural, ride comfort, peace and reliability. Besides, surface roughness is an important basis for the study of soil wind erosion, soil water content, soil and tire coupling. It’s of great significance to study the road roughness, no matter what the pavement condition is. Since 90’s of last century, advanced flatness detecting instrument has been widely used in highway construction, and has overcome the shortcomings of the previous equipment. When designing of non-contact laser ground roughness measuring instrument, the thesis will be based on the development of highway pavement roughness instrument, combine with its own measuring features, develop automation measuring instruments through utilization of laser ranging technology to reach the purpose of measuring, and provide measurement data for further study and analysis.This paper first analyzes the measuring principle of the instrument, and the overall design scheme of the test surface roughness instrument according to the test requirements. Ground roughness tester is an automated test instrument, which is relied on the movement experiment platform, centered on laser sensor and signal acquisition on the basis of LabVIEW, and based on virtual communication control based on PC and SCM. Secondly, the instrument experimental bench are analyzed. According to the design scheme, the frame requirements are proposed, including, weight, volume, transportation, installation, adjustment, error, and selection and selection; transmission scheme will be designed, and overall model will be conducted so as to ensure the feasibility of the scheme.As to the motion platform control box part, motor, driver and controller will be selected according to the motion requirements, so as to complete the components’wiring in the control box and realize the motion plan.Furthermore, the thesis will make an interpretation on the design of signal acquisition based on LabVIEW and virtual control. According to the design requirements, the thesis will write acquisition interface VI and program, and complete signal acquisition of real-time display and storage. The core of the design of the control interface of the virtual instrument based on Lab VIEW is the communication between PC and scm. And in this part the thesis will design the PC machine communication interface of the software LabVIEw and program, communication hardware circuit, and write MCU communication program. According to the designed control interface, the function and using method of each part will be introduced in detail.After the processing and completing of the testing instrument, debugging of the measurement experiment of the prototype will be conducted to test accuracy, in order to provide follow-up guarantee for mature measurement and test precision of the measurement instrument.