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Mechanical Engineering

Dynamics and Control of Lightweight Industrial Mobile Robot Manipulators for Smart Manufacturing under Industry 4.0

Zhengxue Zhou
Zhengxue Zhou

This project intends to research the dynamics and control of lightweight industrial mobile robot manipulators under Industry 4.0. Because of light weight, the component flexibility of the robot needs to be taken into account in the dynamics and control. It is also more important to analyse its dynamic problem by considering the influence of the dynamic interactions based on a more precise mathematical model. So, a new control scheme based on the model will be developed to make the mobile robot manipulator more efficient so they work safely alongside human co-workers for smart manufacturing under Industry 4.0. The control scheme can be optimised by considering dynamic compensation.

Finally, to validate and optimise the proposed kinematic and dynamic model and control scheme, extensive experiments will be conducted on a lightweight mobile robot manipulator.

ABOUT THE PROJECT


Project title:
Dynamics and control of lightweight industrial mobile robot manipulators for smart manufacturing under Industry 4.0

PhD student: Zhengxue Zhou

Contact: zhouzx@eng.au.dk

Project period: Sep 2019 to Aug 2022

Main supervisor: Assoc. Prof. Xuping Zhang

Co-supervisors: Prof. Thomas Skjødeberg Toftegaard

Research section: Mechanical Engineering


Fundamental socio-techno-economic modelling of the energy system transformation and the derivation of long-term sustainable strategies for Denmark in a European context

Leon Joachim Schwenk-Nebbe
Leon Joachim Schwenk-Nebbe

The Danish government has announced plans to make the country fossil-fuel free by 2050. Likewise, the European neighbours have ambitious targets. This transformation is one of the biggest challenges of our society. Techno-economical modelling and optimisation approaches are able to deliver first guidance principles for such pathways, but more than this needs to be taken into account. The dynamics of investor decision making, the formation and design of new market rules, the influence of social acceptance and the impact of climate change are going to strongly influence the development of a future highly efficient energy technology portfolio. More fundamental knowledge of these interactions is required to supply policy and commercial decision makers with a quantitative description of how to implement the transformation of the energy system in the best possible, most cost-efficient and robust manner.

We will use our competencies in the modelling of networked renewable energy systems: the description of the Danish energy system will include the internal coupling between the energy sectors electricity, heating and transportation, and the external coupling to the energy systems of the neighbouring countries.

Optimal techno-economic systems will be derived, for instance by invoking an increase of the CO2 emission constraint, subsidising specific technologies, etc. The scenarios are transformed to pathways by modelling them as emerging from the current energy system. The transition dynamics of the individual nodes are analysed and compared. With the energy systems becoming more distributed - decentralised renewable capacity replaces centralised conventional generation capacity - the generation capacity does not only become more spatially distributed but also opens up the possibility for an increased number of smaller actors in the market. We will seek the right incentives and regulations which are necessary to guide a large amount of decentral investments to overall follow an optimal transformation of the energy system.

ABOUT THE PROJECT


Project title:
Fundamental socio-techno-economic modelling of the energy system transformation and the derivation of long-term sustainable strategies for Denmark in a European context

PhD student: Leon Joachim Schwenk-Nebbe

Contact: leonsn@eng.au.dk

Project period: March 2019 to Feb 2022

Main supervisor: Prof. Martin Greiner

Co-supervisors: Assoc. Prof. Gorm Bruun Andresen and Marianne Zandersen

Research section: Mechanical Engineering


Physics-based Modelling and Simulation of Arable Soil-Tool Interaction

AGROINTELLI is a Danish-based international development company with the goal of transforming research into products to the agricultural industry. The company relies on research-based development of products in the fields of robotics, machine vision and in-field navigation.

In agricultural engineering and research, tests and field trials are often limited to specific seasons. To accommodate this, modelling and simulation-based approaches are gaining ground in the industry.      

By means of this project, AGROINTELLI wishes to increase the focus on the sub-surface soil displacements of a tillage process. The scope of this research is methods for modelling and simulating arable soil-tool interaction. Hereby we can test, evaluate and optimise a soil-engaging tool in a virtual setting before entering the field.

ABOUT THE PROJECT


Project title: 
Physics-based modelling and simulation of arable soil-tool interaction

PhD student: Frederik Foldager

Contact: ffo@eng.au.dk

Project period: April 2018 to March 2021

Main supervisor: Prof. (Docent) Ole Balling

Research section: Mechanical Engineering


Modal Dynamics and Design Analysis of Multi‐Rotor Wind Turbines

Oliver Tierdad Filsoof

Project description:
The dynamics of wind turbines with multiple rotors connected on a single structure is more complex than that of conventional wind turbines with a single-rotor. In the design of multi-rotor turbines, it is therefore important to have appropriate estimates of the system and modal frequencies. Various modal analysis methods are available for single-rotor wind turbines, but there are no report and guidance on the modal property analysis of multi‐rotor wind turbines. This PhD will thus be the first state‐of‐the‐art on modal analysis of multi‐rotor wind turbines.

Research Questions
The basic research questions of this PhD project are:

  • What are the modal dynamics for multi-rotor wind turbines with different number of rotors?
  • What is the optimal design for multi-rotor wind turbines based on resonance response and stability?

Objective
The overall objective of this project is to develop a methodology for modal analysis of multi-rotor wind turbines by leveraging the technologies in multibody dynamics, structural dynamics and aerodynamics of wind turbines.

ABOUT THE PROJECT


Project title:
Modal dynamics and design analysis of multi‐rotor wind turbines

PhD student: Oliver Tierdad Filsoof

Contact: otf@eng.au.dk

Project period: Jan 2018 to Jan 2021

Main supervisor: Assoc. Prof. Xuping Zhang

Co-supervisor: Morten Hartvig Hansen

Research section: Mechanical Engineering


Joint Dynamics and Adaptive Feedforward Control of Lightweight Industrial Robots

Emil Madsen

Universal Robots is a world leader in collaborative robots which they develop, manufacture and sell. These robots can work safely alongside human co-workers in collaborative ways because they respect some safety standards, unlike traditional industrial robots that need to be fenced off away from humans.

Universal Robots seeks to further enhance the speed, precision, and safety of their robots. Mechanical wear, temperature changes, etc. do however introduce uncertainties and disturbances to the governing mathematical models.

This project aims to improve the robot performance by; 1) developing an accurate mathematical description of the joint flexibility and friction, and 2) designing a new controller architecture enabling the robot to monitor and evaluate its performance and use this information to adapt to changes. The findings from this project should be implemented as a software update on existing and future robots, making this approach extremely valuable.

ABOUT THE PROJECT


Project title:
Joint dynamics and adaptive feedforward control of lightweight industrial robots

PhD student: Emil Madsen

Contact: ema@eng.au.dk

Project period: July 2017 to June 2020

Main supervisor: Assoc. Prof. Xuping Zhang

Research section: Mechanical Engineering


Modelling of sector coupling in emerging large-scale renewable energy networks

Kun Zhu

The overall aim is to develop and use a two-dimensional interconnectivity modelling approach to design robust and cost-effective investment strategies towards a sustainable energy system. The overall aim is to better understand the next feasible investments to move towards a low-carbon sustainable energy future.

There are three main objectives to achieve in this PhD project. The first objective is to establish the energy system simulation environment for future analyses. The second is to establish empirical scenarios for the year 2050 in which different technologies will be tested. The last objective is to generate robust investment strategies for the Danish energy transition.

ABOUT THE PROJECT


Project title:
Modelling of sector coupling in emerging large-scale renewable energy networks

PhD student: Kun Zhu

Contact: kunzhu@eng.au.dk

Project period: May 2017 to April 2020

Main supervisor: Prof. Martin Greiner

Co-supervisor: Assistant Prof. Gorm Andresen

Research section: Mechanical Engineering


Impact of climate change on highly renewable large-scale energy systems

Smail Kozarcanin

Denmark is currently on the verge of a transition to a fundamentally different energy system where the share of renewable weather-driven power generation exceeds that of conventional sources. Many rich and developing countries around the world share similar ambitions as renewable energy is the key for solving the global issues of climate change and energy. To achieve a possible solution, a high share of renewable energy sources needs to be taken into consideration and a highly renewable energy system that is robust against climate change needs to be designed.

Typically, existing studies rely on historical weather and energy data from publicly available sources to investigate properties of renewable energy systems - many decades into the future. In this project, newly available climate change projection data from the EURO-CORDEX project will be combined with the existing reanalysis data in the Global Renewable Energy Atlas (REatlas) to produce realistic high-resolution time series of wind and solar power production for all European countries. These will then be used in the weather-driven modelling approach, pioneered at Aarhus University, to analyse the impact of climate change on current and future renewable energy systems. The first study will take offset in the master thesis by Smail Kozarcanin.

ABOUT THE PROJECT


Project title:
Impact of climate change on highly renewable large-scale energy systems

PhD student: Smail Kozarcanin

Contact: sko@eng.au.dk

Project period: Nov 2016 to Oct 2019

Main supervisor: Prof. Martin Greiner

Co-supervisor: Assistant Prof. Gorm Andresen

Research section: Mechanical Engineering


Techno-economical and market design of a highly renewable large-scale Chinese electricity system

Renewable energy, especially wind power, has been developing rapidly in China due to a series of incentive policies. Now it is the world’s largest producer of wind and solar energy, but the sector has long been criticised for problems connecting to the grid or having its output used fully.

The reason behind this is a combination of system failures, low demand and technical bottlenecks. Older issues are systemic – planning for generation and transmission are not coordinated; the grid fails to keep up with the rising capacity of renewable power, etc. Moreover, wind power is intermittent and to ensure a robust power system, it needs to be complemented with other sources of electricity to sustain a stable supply. 

To achieve this, we will investigate the ability of the existing Chinese energy system to integrate fluctuating wind power and explore how the power system can prepare itself for integrating more fluctuating renewable energy in the future.

ABOUT THE PROJECT


Project title:
Techno-economical and market design of a highly renewable large-scale Chinese electricity system

PhD student: Hailiang Liu

Contact: hll@eng.au.dk

Project period: Sept 2016 to Aug 2019

Main supervisor: Prof. Martin Greiner

Co-supervisor: Assistant Prof. Gorm Andresen

Research section: Mechanical Engineering


Vibration Analysis and Control of UR Robot Manipulators with the Consideration of Link and Joint Flexibility

Dan Kielsholm Thomsen

Universal Robots develops and manufactures collaborative robots. Collaborative robots have a high safety level that makes human-robot collaboration possible, and the robots are meant to work alongside humans as co-workers. Universal Robots strives to improve its products in productivity, precision and versatility.

This project intends to improve all these points by an effective reduction of mechanical vibrations in the robots. All electromechanical systems experience vibrations and when compared to the conventionally heavy industrial robots, collaborative robots are sensitive to vibrations due to light weight structures.

The improvements are to be obtained by precise dynamic modelling of mechanical deflection in the robot. This dynamic model will be used to slightly change the behaviour of the robot for reducing induced vibrations. This approach is preferable because it will be possible to implement it in all existing and future robots and it is only a software concern.

ABOUT THE PROJECT


Project title:
Vibration analysis and control of UR robot manipulators with the consideration of link and joint flexibility

PhD student: Dan Kielsholm Thomsen

Contact: dkt@eng.au.dk

Project period: July 2016 to June 2019

Main supervisor: Assoc. Prof. Xuping Zhang

Co-supervisor: Prof. (Docent) Ole Balling

Research section: Mechanical Engineering


Development of Mobile Machining Cell for the Wind Turbine Industry

Kasper Ringgaard

A consortium of Danish universities and companies have come up with an idea that could save billions in the wind turbine industry. The aim of the project, named InnoMill, is to develop mobile machining cells for machining of large wind turbine cast steel components.

Increasing energy consumption
Globally the demand for cheap renewable energy increases, and therefore the wind energy industry struggles to lower the Cost Of Energy (COE) on wind turbines. To lower the COE the size of the wind turbines increases. Current components measures several metres, which causes transportation of components to become a bottleneck – both in terms of ability to fit them on the road, and the cost of transportation to and from machine shops.

Limiting transportation
One way of limiting the amount of transportation is to perform machining operations on-site instead of the current practice of moving components to large scaled machine shops. The InnoMill project aims to develop such mobile machining cells, but it will not be as straight forward as it may seem. The challenge lies in making the machine accurate enough to meet the high quality standards demanded by the wind turbine industry since it will deflect and vibrate significantly during operation.

Solution strategy
The researchers believe that the challenge can be overcome by gaining knowledge of stiffness and vibrational levels in the system throughout the entire machining process. During development of the machine, thorough analyses of the stiffness and vibrations will be used to predict and avoid unsuitable machine designs and machining patterns. During machine operation, different values will be monitored to allow the machine control to adjust such that the quality standards can be fulfilled. Scientists hope that this will enable the machine to meet the stringent quality standards.

The PhD project
The aim of this PhD project is to develop the simulation models necessary to develop the machine. The models must be able to predict the behaviour of both the component and the machining cell during the machining process. To obtain valid models a great deal of research regarding the sensitivity of the final quality to different factors such as loads, supports and temperature is needed. Research into efficient and precise flexible multibody simulation is also needed to make valid simulations of the entire milling process that can be handled using the computational power available today.

ABOUT THE PROJECT


Project title:
Development of mobile machining cell for the wind turbine industry

PhD student: Kasper Ringgaard

Contact: kri@eng.au.dk

Project period: August 2015 to July 2019

Main supervisor: Prof. (Docent) Ole Balling

Research section: Mechanical Engineering