Research On Active Vibration Control Of Thin-walled Workpiece In Milling Based On Voice Coil Motor

Thin-walled workpieces are the most widely used flexible elements in the industries ofaerospace, shipping, energy resources, automobile and so on. Workpiece machining vibrationgreatly worsens the efficiency and accuracy of milling processes. In order to suppress thevibration of thin-walled workpieces in milling, an active vibration control platform based onvoice coil motors is established.Thin-walled aluminum alloy plate is studied in the project. The laser displacementsensors get the vibration signals of controlled points in milling processes and sent them to thePXI-7852R FPGA card, which is a part of NI PXI control platform. After PID control inFPGA module, the PXI-7852R card outputs control voltage signals to amplifiers and drivers,which can drive the voice coil motors to move and form a closed-loop control so as to changethe damping and stiffness of the whole system and suppress the vibration of thin-walled plate.The real-time control of FPGA based on PID is realized by LabVIEW programming anddownloading the compiled LabVIEW programs to PXI-7852R card. In order to simulate thethin-walled plate vibration induced by milling cutter in early research, one voice coil motor isset as the vibration exciter and another as vibration absorber. The exciter outputs a sinevibration signal, which is provided by PXI-6733high-speed analog output card. In thissimulation experiment, the vibration amplitude can reduce65%-70%when the excited rate isnear the natural frequency, so that the feasibility of using voice coil motors to actively controlthe vibration of thin-walled plate and the effectiveness of closed-loop active control system isverified.The vibration properties of thin-walled plate in milling, which can be known by ANSYSmodal analysis and modal test, is considered when choosing the milling parameters. We carryout the milling experiment by choosing proper milling parameters. The laser displacement sensors placed under the plate and in X、Y directions of cutter detect the vibration signals andsent them to PXI-4472analog acquisition card so that we can view the vibration signalsonline and save them to files. The research afterward will focus on controlling the platedeformation in milling, optimal control algorithms and active control technique of spindle.