Noise robustness improvement of reset control systems using measurement line filtering

Inherent limitations of linear control, including PID, are Bode's phase-gain relationship and the waterbed-effect. Literature showed that reset control can overcome these limitations. The 'Constant in Gain, Lead in Phase' (CgLp) reset element was developed, which can be used in combination with a conventional PID approach. The benefit is that...

Magnetisation state and position control of a hybrid tunable magnet actuator

This report presents two different methods for controlling the remnant magnetisation state of a permanent magnet within a Hybrid Tunable Magnet Actuator. Addressing, individually, the desire for optimum energy efficiency and control accuracy. The purpose of this actuator is to track a quasi-static position reference without continuous thermal...

Design of a Nonlinear Stiffness Unit Cell Aided Magnetic Gravity Compensator

A novel nonlinear stiffness unit cell aided magnetic gravity compensator is proposed for the purpose of isolating low-frequency vibrations. A negative stiffness magnet setup is combined with a compliant unit cell with tailored nonlinear force-displacement characteristics. This combination offers a large range of motion featuring low stiffness, a...

Input and state estimation for compliant motion stages: Estimating modal contribution for guidance flexures

To improve Active Vibration control methods like Independent Modal Space Control (IMSC), an estimate of the modal contribution of vibrational eigenmodes of compliant structures is required. In this work, three Recursive Bayesian input and state estimation algorithms previously introduced in civil engineering are evaluated for use on on high-tech...

Hybrid vibration control with concurrent active piezoelectric and passive viscoelastic damping

The use of passive viscoelastic damping and active piezoelectric damping in a hybrid side-by-side configuration is explored in this paper. The goal is to combine the strengths of both individual methods to achieve better damping performance when targeting a single eigenmode or multiple resonances. It is found that a hybrid configuration where a...

Vibration suppression of a state-of-the-art wafer gripper

Vibration suppression of flexible end-effectors has become one of the great challenges within the semiconductor industry to achieve the precision required to produce chips. These end-effectors tend to be prone to vibrations due to their lightweight design and low thickness, whilst they still should have high accuracy and precision. This...

Overcoming inherent performance limitations in industrial motion stages with reset control: A general approach to the design and implementation of reset controllers validated on an ASMPT AB383 wire bonder

Linear time-invariant controllers are undoubtedly the most popular type of regulators used in industrial applications, with the overwhelming majority of companies employing them. The reason is mainly given by their simple design methods. In particular, frequency domain predictive performance analysis and stability methods allow the use of...

Mechanical design for out-of-plane mode attenuation in flexure mechanisms

The most problematic eigenmode in machines involving flexure mechanisms is represented by flexural modes. However, it can be noticed that also out-of-plane modes, that occur in the space outside the nominal plane of movement of the mechanism, can be very important, especially in machines with several and coupled degrees of freedom, like 3D...

Tunable Magnet Actuators: Hysteresis Modelling for Efficient and Accurate Magnetization State Tuning

In this thesis, the accuracy and efficiency of Magnetization State (MS) tuning in Tunable Magnet Actuators (TMAs) is investigated. TMAs are developed to improve thermal stability in quasi-static precision actuation applications. First, the operating principles of TMAs and limitations in previous work are discussed respectively. It is found that...

Robotic Metamaterial with Odd Elasticity: Design and testing of a Metamaterial with novel actuation and control method

Going beyond naturally occurring materials, Metamaterials exploit a design at the microscale resulting in macroscopic behaviour, to achieve different or even new properties that can have a wide range of applications. By incorporating sensors, actuators and control, Robotic Metamaterials can achieve even more extremely different behaviour such as...

Improving the noise robustness of reset controllers with an observer

The performance of linear control is limited by the waterbed effect, while the performance demands of industry are continuously increasing. Using non-linear control in the future is therefore unavoidable. Being non-linear, reset control is able to achieve better performance than linear control. However, the lack of robustness to measurement...

Hybrid Tunable Magnet Actuator: Design of a linearized force-flux tunable magnet actuator

To achieve high motion accuracy and repeatability for a variable reluctance tunable magnet actuator that uses linear controllers, this article proposes a novel actuator design that has a linearized force-flux relation. Prior designed variable reluctance tunable magnet actuators use a C-shaped actuator that has a quadratic relation between the...

Time-division multiplexing is used as a method to reduce the number of amplifiers needed in active vibration control systems that use piezoelectric actuators

The high-tech industry is constantly searching for methods to make more efficient, more accurate, and faster machines. One of the methods to improve the performance of these machines is active vibration control(AVC) which can help to achieve faster transient responses. One of the ways to achieve this is better controllability which means more...

Smart Material Actuated Inkjet Printed Robotic Fish

Several underwater activities like exploration, surveillance, measuring key characteristics like water current or temperature, and mapping seabed risk human lives as the underwater conditions are hostile. Developing underwater vehicles provides a solution to minimize risking human lives. The underwater robots developed based on conventional...

Novel Designs to Improve Support Stiffness during Large Strokes in Compliant Mechanism

The precision, speed, and stroke of mechatronic machines need continuous improvement. Compliant mechanisms are widely used in the precision machines, but they do not have larger strokes due to their limited deformation. In the present time, various applications also require high speed and more problems appear due to the dynamics of the compliant...

Smart magnetic fluids: Controllable distributedfluidic actuation

This thesis is centred around the problem that heart failures become more common when other dis-eases could be treated better. Although surgery could fix the immediate effects of heart failures, therecovery after the surgery is hindered by the heart not being able to pump enough blood. There aresolutions available but they are not implemented...

A Predictive Energy Management Strategy for Plug-in Hybrid Electric Vehicles utilizing Route Preview

A Plug-in Hybrid Electric Vehicle (PHEV) can achieve a considerably higher overall fuel economy than conventional vehicles. The fuel economy of PHEVs however, strongly depends on the supervisory control strategy of the hybrid powertrain. Compared to conventional, non-predictive, supervisory control systems, predictive control methods can further...

Piezo-Stepper actuator, Self-Sensing, Impedance Control

Piezo-Stepper actuators also called as piezowalk actuators find widespread application in precision mechatronic systems. This is primarily because of their high accuracy, long range of motion and compact volume. One such application is in the optical column manipulator of a lithography system. During operation, whenever a motion is desired...