The most widely applied feedback controller is PID. This controller gains its popularity because of the ease of design through loop shaping, since PID can be analyzed in the frequency domain. However, PID is limited by linearity. Reset control is a nonlinear addition to PID control. Through linearization techniques it can be designed by analyzing the frequency domain. Through numerous numerical, analytical and practical experiments it has been shown that reset control can outperformPID. However, when practically implementing reset control, especially in motion stages, one aspect can cause severe performance degradation. Research is underrepresented in this field. Quantization can be described as discretization in the amplitude. This thesis aims to reduce the quantization induced performance degradation. Two methods are proposed: reset band and time regularization. Numerical analysis and practical experiments have been performed in order to analyze the performance degradation and proposed methods. Through the numerical analysis in matlab simulink of a mass system the performance degradation has clearly been addressed. Based on the new understanding tuning rules have been provided for both proposed methods. A preliminary sensitivity analysis shows the robustness of both methods. Both proposed methods show enhanced performance. In numerical analysis it was shown that the reset band solution and time regularization can achieve an improvement of up to 10 dB. It was shown through experiments on a high level motion stage that several dB improvement is feasible. For the reset band at a specifically detrimental frequency the error was reduced from 200 nm to 70 nm. The reset band shows an improvement of several dB. In one setup, the performance enhancement spanned a wide frequency range. Overall it is concluded that for quantization induced performance degradation both proposed methods clearly show improvement. Two novel applications of existing methods have shown an increase in performance. New tuning guidelines have been provided.

The PID controller is one of the most used controllers in the industry. However, fundamental limitations due to linearity restrict its performances when higher bandwidth, stability, and precision are required simultaneously in today’s high-tech industry. Reset control is a promising nonlinear control strategy which can overcome these limitations. But it also brings new problems.
High order harmonics are introduced into the system because of non-linearity which lead to unwanted dynamics and deterioration of performances. So it is necessary to reduce them as much as possible. It is found that the sequence of different parts of a reset controller has effects on the magnitude of high order harmonics. Through high order sinusoidal input describing functions (HOSIDOFs) tool, the optimal sequence of the open loop in which the magnitude of high order harmonics is minimum is achieved for a general reset controller. The superiority of the suggested sequence in the closed-loop system is validated through both simulation and experiments at a Lorentz-actuated precision positioning stage.

The application of actively controlled micrometer precision positioning stages in products that are accessible to start-ups, individual consumers or third world countries is currently limited by their price and size. To solve this problem, the use of low-cost and compact components in stages is investigated. Earlier research done in the MSD group already showed that relatively low-cost sensor concepts and mechanical designs can be applied to significantly reduce the price of stages, while still achieving sub-micrometer precision. In this research, the applicability of the Arduino Due micro-controller (€40) and amplifiers based on Pulse Width Modulation (PWM, €6) in precision stages is investigated. The use of
cheap components doesn’t come without its drawbacks. To name a few examples, the Analog-to-Digital Converter (ADC) in the Arduino doesn’t have the resolution of higher quality components, PWM adds frequency content to the output of the amplifier and the Arduino processor isn’t as fast. In this research project, an extensive theoretical analysis is done to reveal how the components affect the overall performance of the stage, which can then be used to optimize system parameters to circumvent the performance losses that are inevitable with cheap components. This way much of the overall system performance can
be maintained. The theory is experimentally validated and the Arduino and PWM based amplifiers are successfully implemented into a working prototype with a precision of 1.5μm.

To push the performance of the next generation Ultimaker 3D printers further, a new positioning system is required to improve the printing speed, print accuracy and print repeatability. The expectation is that a linear motor positioning system will perform significantly better than a conventional belt driven system. For this reason, the aim of this MSc thesis is to demonstrate the feasibility of a low-cost linear motor positioning system for use in a 3D printer.
A single axis experimental set-up is realized to evaluate the performance of the positioning system using different linear motors, sensors, guides and controllers. Using a single sided ironless linear motor, Hall effect encoder, linear ball bearing and an open-source controller, a positioning system is realized that can reach a speed of 3.7 m/s, an accuracy of 14 µm and a repeatability of 3 µm. A 2DOF system using these components can be realized with an overall cost of € 854.

A new concept was developed to improve current airpot designs for vibration isolation solutions. The concept is based on an additional piston, or add-on, with certain characteristics, that is to be incorporated into an existing airpot-design. The effect of this add-on will passively improve the vibration isolation performance of the airpot. This research into this add-on concept consists of the modelling of this concept , the design of a demonstrator and a comparison between modelled and measurements.

PID is the most commonly used technique in industrial motion control. It consists of three components - lead, lag and low pass filter (LPF). PID, being a linear control method is inherently bounded by waterbed effect due to which there exists a trade-off between precision, tracking, and stability. Reset control is a nonlinear technique which shows promise in overcoming certain limitations. Despite the promise shown, the use of reset elements other than integrator within the framework of PID for improved performance has not been well investigated. This thesis work focuses on implementing reset in lead part and in LPF in order to reduce the severity of the waterbed effect in PID. Three controllers have been developed that provide improvements in bandwidth, precision, and tracking. The controllers were implemented in a Lorentz-actuated nanometer precision stage and the performance has been validated in both time and frequency domain.