Modeling And Compensating For System Errors Of Crankshaft Measuring Machine

Due to the engine crankshaft has an important influence on the car’sperformance, the crankshaft manufacturing has become a key step inautomotive industry. Groove is an important part in the crankshaft structure,it makes sure the stress on shaft neck won’t focus, and ensuring the fatiguedamage will not occur when crankshafts are using. So measuring the keysize of crankshaft with high precision is an important way to guaranteemanufacturing precision and efficiency of crankshaft.With improvement of the crankshaft machining accuracy, therequirement of measuring accuracy is higher, precision and errorcompensation on the Crankshaft Image System can further improve theaccuracy of measurement, and has a very vital significance. Based on thedeveloped Crankshaft Image System, this paper analyzes the precision anderror of the system, then conduct analysis, optimization and process.The acquisition technology for high quality image has been researched,through the improvement of the system hardware, the optimizing of core algorithm and2-d calibration method, the measuring accuracy of theCrankshaft Image System has been improved.The space error modeling method based on the multi-body system hasbeen researched, the space error of the crankshaft image system has beencomprehensive analysed, then establish and optimize the space error modelof Crankshaft Image System.The methods based on the Laser Tracker for measuring space errorquickly and accurately has been researched, including the measurement ofCrankshaft Image System geometric error and analysis of the influence toCrankshaft Image System; the measurement of3-axis space motion errorand analysis of the measurement result, then calculate the space error value.The error modeling and error measurement method for CrankshaftImage System based on laser tracking has been validated by experiment,with the Laser tracker, the space error of Crankshaft Image System can beenmeasured fastly and accurately. First, the geometric error of crankshaftimage system has been measured and analysed, then the3-d space motionerror has been measured and the value of the error source has beencalculated, at last the system integrated error compensation has beenverified, and the measurement accuracy has been improved.