Advanced control techniques for motion control problem

Common methods used for solving low-frequency mechanical resonance in industrial servo systems are often inadequate. Linear and non-linear algorithms to cure low frequency mechanical resonance are proposed. A novel controller based on the multi-resolution decomposition property of wavelets, called the Multiresolution Wavelet Controller is developed. The controller is similar to a Proportional-Integral-Derivative controller in principle and application. The output from a motion control system represents the cumulative effect of uncertainties such as measurement noise, frictional variation and external torque disturbances, which manifest at different scales. The wavelet is used to decompose the error signal into signals at different scales. These signals are then used to compensate for the uncertainties in the plant. This controller is further applied to other industrial applications to validate the control scheme. A scheme to generate low noise differential signal using wavelets is also developed. Wavelet transforms are investigated for their ability to solve industrial control issues such as noise, disturbance, and improving loop bandwidth.