Research On Base Levelness Measurement And Auto-leveling Method

During the construction course of the hulls,the flatness and levelness of the hall bases are the key factors that affect the construction quality.The plane of the base may divide into the horizontal plane and the inclined plane,so the flatness of the inclined plane also needs to be measured.Requests to the maching accuracy of the hall base are generally high.The flatness and levelness need to be processed precisely using the special machine.So the hall bases need to be carried on high precision measurement before and after machine tool machining.In the project that cooperates with Bohai ship heavy industry company,use laser scaning method to measure flatness.This system is mainly designed for realizing levelness measurement of the laser scanning plane,and the automatic adjusting the levelness of the base for flatness measurement.While the available measuring instrument can not meet the actual requirement,so in this paper according to the client's needs,a levelness measurement and automatic leveling system are designed.This paper proposes the whole design scheme,according to the scene environment, adopt a dividing form in this system convenient to operation.That is,levelness measurement subsystem and automatic leveling subsystem run singlely.For the levelness measurement subsystem,transform inclination to analog voltage signal with a high accuracy two-dimensional tilt sensor.Design a circuit for the data acquisition and processing taking PIC16F877 as the control center,mainly includes a 24-bit A/D transformation module,temperature compensation module and communication module, to complete the data acquisition.The sensing scope of the high precision tilt sensor is not large,the precision is the highest nearby the measuring centerpoint within the full range.There the automatic leveling subsystem is designed that can automaticly adjust the state of the planeness measuring platform.This subsystem use PIC16F877 as the control core,mainly includes coumunication module,keystroke module,display module and step motor control module.Finally,according to system requirement,corresponding software is designed to complete the ruction of each subsystem.Preliminiary lab experiments indicate that,the levelness measurement subsystem has realized data sampling,and the automatic leveling subsystem can adjust the state of the planeness measuring platform.All of this meet the customer demand basically.