Research On NonContact Height Difference Measurement Machine

This paper designed a noncontact height difference machine according toproblem of CCD lens fixing precision measurement, which was raised by the 8358graduate school. This paper discussed all of the problems about the measurementmeachine in detail, such as designing the measurement principle, implementing thetechnic channel, analysing the feasibility, mechanical design, control system designand software design.This paper designed an absolutely new method to measure the depth of roundhole based on the real problem, which is to measure the fixed depth of CCD lens inbottom of a round hole. This method could be used to measure the depth differencebetween the planes. The method takes the capacitance micrometer as its core, usesmulti-sensors to mesure together, gets the result through fusing the multi-sensor's data.We successed in measuring the workpiece noncontactly and precisely by using thecapacitance micrometer's high precision and noncontact measurement advantage,protecting the workpiece effectively. Because we use several sensors, they aresensitive to the environment, then drift in the same direction, and as a result restrainthe data drift using one sensor. In this method, the stability can be enhanced, themeasuring precision is well advanced. Research work is described as follows in detailin this paper:1. Go deep into the height difference measurement method, considering theworkpiece's fact case, this paper designs a method to measure the height difference.The feasibility of the method is discussed.2. On the basis of the method, a completely adaptive measuring system isdesigned, the design of the system includes mechanism design, controlling systemdesign and the software design.3. Using 5 capacitance micrometers to design an adapative measuring head,which can accommodate its pose to measure according to the workpiece's put state.4. The capacitance and the measurement's demarcate and error correct methodsare expatiated in detail, the factors to bring the system's measuring error are analysedand concluded.The machine was well designed and factured completely, its measurementrepetition and measurement linearity were both identified by the National Institute ofMetrology. So far the machine is running steadily after it was handed to the user. Themachine's success settled the 8358 graduate school's CCD lens fixing measurementproblem.