Research On Design And Experiments Of Control System Based On Noncircular Turning

In order to adapt to the special function requirements in specific circumstances，somecylindrical parts needed to design to noncircular cross section，which produced special lawof motion. In the noncircular machining with soft profiling, considering the periodiccharacteristics of the given reference instructions and the external disturbance signal, thefeeding systems was controlled to make high-speed reciprocating movement and producenoncircular profile. This method of turning had advantages of good flexibility and highprocessing accuracy. It could be switched to different mode in processing different kinds ofnoncircular cross section by modifying soft profiling parameters. However, when thenon-roundness of noncircular cross section parts was big, the cutting angle and cutting speedchanged greatly, which followed periodic law. Therefore, it greatly reduced the service lifeof cutting tools and the processing quality of parts.The article designed a new type of turning tool rest and it could adjust the angle ofcutting tool and spindle speed in real time to ensure that the cutting angle and the cuttingspeed was constant in the process of turning processing. Different from traditional softprofiling noncircular machining, the new tool rest had two degree of freedom droved by twoactuators, whose motion synthesis produced design track. It compensated the cutting anglechanges caused by the changes of contour section on rotating work pieces by drivingswinging actuators to adjust tool angle. This angle was just the pressure angle at the cuttingposition.In order to realize high speed digital noncircular machining, a complete set ofnoncircular machining platform was set up, equipped with high-speed PMAC motioncontroller and the control algorithm of the control system was simulated. According to theworking principle and structure characteristics of the new tool rest, it practiced motionmodeling to the quick feeding mechanism, made dynamic performance test experiments,completed noncircular section processing practically. Experimental results verified thefeasibility of the scheme designed and the reliability of the control strategy.