![]() For assessing simulation results, the proper indicator of vibration level must be selected, which is also discussed in the paper. The FEM parameters are tuned based on modal tests of the actual workpiece. The simulations utilize the model of the workpiece with adjustable supports in the convention of a Finite Element Model (FEM) and a dynamic model of the milling process. To reduce the vibration level during milling, it is necessary to appropriately set the support stiffness coefficients, which are obtained from numerous milling process simulations. This affects the modal parameters of the whole system, i.e., object and its supports, which is essential from the point of view of the relative tool–workpiece vibrations. For this purpose, it is proposed that the standard supports of the workpiece be replaced with adjustable stiffness supports. This paper concerns the problem of vibration reduction during milling. Since the proposed scheme is model-free and much simpler to implement than other previous adaptive gain updating schemes found in the literature, and efficacy of the scheme is demonstrated experimentally, it has great potential for industrial use. With the adaptive gain tuning scheme, higher gain increments with shorter updating times are observed to result in the process being stabilized quicker. For slot milling of steel, active damping of unstable vibrations is shown to stabilize the process and improve productivity by up to ~ 300%. #AIRMOUNT HDD SUSPENSION MOUNT SYSTEM UPDATE#Since the amount of force to be applied is governed by the actuator type and by the level of instability detected, efficacy of proposed adaptive gain tuning scheme is tested for its dependence on the time required to update the gain and for its dependence on the levels of gain increments. The actuator then applies a suitable compensatory force on the flexure to damp the vibrations. If/when instabilities are detected, an active damper that is mounted on a flexure is supplied an appropriate control signal based on a velocity feedback control law. Vibrations during the cutting process are monitored using an accelerometer. To apply only as much force as is necessary to stabilize the process, a novel adaptive and model-free gain tuning method is proposed in which gains are adapted to the level of unstable vibrations detected during machining. This paper discusses the use of active vibration control to suppress chatter in a milling process. It must hence be avoided and/or suppressed. All controllers and automatic tuning methodologies led to notable increase in chatter-free material removal rates, reduced vibration amplitudes, and improved surface roughness.Ĭhatter can damage parts. The performance was evaluated by conducting extensive cutting tests under industrial operating conditions. The proposed method was tested on both a 5-axis milling machine and a vertical lathe, together with an automatically tuned direct velocity feedback controller and an adaptive controller. This paper presents a new automatic tuning approach for a robust model-based controller, which uses particle swarm optimization to find the best-performing control parameters. In order to reduce the commissioning effort, previous publications have introduced methodologies to automatically tune various control strategies for active damping. The use of active vibration control systems can damp the structural mode shapes and, in turn, significantly increase the chatter-free depth of cut. Chatter is the main limiting factor affecting the material removal rates of machine tools and is caused by the machine's most flexible structural mode shapes. ![]()
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