Disturbance attenuation in discrete-time Kuramoto models: n/a

This thesis reports the results of research into the stability of the all-to-all coupled discrete time Kuramoto model under constant, matched input disturbances. The discrete time Kuramoto model can be used as a dynamic, decentralized multi-agent orientation coordination system: once initialized, the agents will communicate their orientations to...

Gaussian process repetitive control: Beyond periodic internal models through kernels

Repetitive control enables the exact compensation of periodic disturbances if the internal model is appropriately selected. The aim of this paper is to develop a novel synthesis technique for repetitive control (RC) based on a new more general internal model. By employing a Gaussian process internal model, asymptotic rejection is obtained for...

Distributed Adaptive Consensus Disturbance Rejection: a Directed-spanning-tree Perspective

In this paper, we revisit the problem of consensus disturbance rejection for multiagent systems over a digraph, but from a different perspective, i.e., the perspective of a directed spanning tree (DST). When the minimum nonzero real part of the Laplacian eigenvalues is available, we reproduce the sufficient lower bound for a static...

Dual-axis tilting rotor quad-plane design, simulation, flight and performance comparison with a conventional quad-plane design

In the last few decades, the UAV research has been focusing on hybrid vehicles with Vertical Takeoff and Landing (VTOL) capabilities. Opposed to copters, hybrid vehicles are highly influenced by wind disturbances. This paper presents a novel quad-plane design that uses four dual-axis tilting rotors to enhance the wind rejection capability of...

Active Disturbance Rejection Control for Uncertain Nonlinear Systems With Sporadic Measurements

This paper deals with the problem of active disturbance rejection control (ADRC) design for a class of uncertain nonlinear systems with sporadic measurements. A novel extended state observer (ESO) is designed in a cascade form consisting of a continuous time estimator, a continuous observation error predictor, and a reset compensator. The...

Assistive Shopping Trolley Controller Design for the Elderly

We are living in an aging society, which is putting an increasingly heavy strain on our healthcare system. As people age many become less mobile, leading to loneliness and a deteriorating health. Subsequently elderly often end up in nursing homes; an experience which is unpleasant as well as expensive. Assisting the elderly with robotic devices...

Feedforward control for wave disturbance rejection on floating offshore wind turbines

Classical feedback control for floating offshore wind turbines has limited capabilities to reduce wave disturbances. Feedforward control uses disturbance measurement, to construct an additional control law such that the disturbance is attenuated. The main objective of this work is to prove the concept of wave-FF control to attenuate wave...

Decoupling Control of Multiactive Bridge Converters Using Linear Active Disturbance Rejection

Multiactive bridge (MAB) converter is a promising solution for integrating multiple renewable sources, storage, and loads for various applications. However, the MAB converter is challenging to control due to the inherent coupling between the port power flows. To that end, this article presents a decoupling control strategy based on linear...

Controllability of solar-sail orbits in the Earth-Moon system

The propellantless nature of solar-sail propulsion allows researchers to design completely new sets of orbits unreachable or not-maintainable by means of conventional propulsion. The advantage of this somewhat new type of low-thrust propulsion system becomes more evident for long-duration missions where chemical or electrical rocket engines...

Reset control for vibration disturbance rejection

The high tech industry which requires fast stable motion with nanometer precision continues to mainly use PID which is limited by fundamental linear control limitations. Floor vibrations as disturbance significantly affect performance and their rejection is particularly affected by these limitations. Reset control has provided a promising...

Quadrotor fault-tolerant incremental nonsingular terminal sliding mode control

This paper proposes incremental nonsingular terminal sliding mode control for a class of multi-input and multi-output nonlinear systems considering model uncertainties, external disturbances, and sudden actuator faults. This method is free from singularity because it does not involve any negative fractional power. The convergence time in both...

Path Following Control Design for Passenger Comfort Under Disturbances

In recent years, enormous progress has been made in the field of automated driving. As a consequence, automated driving technologies are becoming increasingly popular. Research on comfort for autonomous vehicles, however, is still limited and unexplored. Some researchers address the comfort issue in path planning by velocity profiles, which...

Reset Control for Vibration Isolation

Floor vibrations are a common problem in high tech engineering where good tracking, precision and bandwidth have utmost importance. They are mainly present at low frequencies, and they need to be suppressed. PID control is the go-to controller in the industry because of its ease of design, simple implementation and good performance. However, PID...

Cascaded incremental nonlinear dynamic inversion for MAV disturbance rejection

This paper presents the cascaded integration of Incremental Nonlinear Dynamic Inversion (INDI) for attitude control and INDI for position control of micro air vehicles. Significant improvements over a traditional Proportional Integral Derivative (PID) controller are demonstrated in an experiment where the quadrotor flies in and out of a 10 m...

Optimal leg compliance for rejecting disturbances in bipedal running

The optimal leg compliance to reject disturbances in bipedal running was determined. An optimization study was performed, in which the potential energy in the leg of a model with a flat foot was optimized. The optimal disturbance rejection behavior improves w.r.t. foot length up to a factor 3 w.r.t. zero foot length.

Swing-Leg Retraction for Limit Cycle Walkers Improves Disturbance Rejection

Limit cycle walkers are bipeds that exhibit a stable cyclic gaitwithout requiring local controllability at all times during gait. A well-known example of limit cycle walking is McGeer’s “passive dynamic walking,” but the concept expands to actuated bipeds as involved in this study. One of the stabilizing effects in limit cycle walkers is the...