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Topics in Machining with Industrial Robots and Optimal Control of Vehicles

Olofsson, Björn LU (2013) In Research Reports TFRT-3259
Abstract
Two main topics are considered in this thesis: Machining with industrial robots and optimal control of road-vehicles in critical maneuvers. The motivation for research on the first subject is the need for flexible and accurate production processes employing industrial robots as their main component. The challenge to overcome here is to achieve high-accuracy machining solutions, in spite of strong process forces affecting the robot end-effector. Because of the process forces, the nonlinear dynamics of the manipulator, such as the joint compliance and backlash, significantly degrade the achieved position accuracy of the machined part. In this thesis, a macro/micro manipulator configuration is considered to the purpose of increasing the... (More)
Two main topics are considered in this thesis: Machining with industrial robots and optimal control of road-vehicles in critical maneuvers. The motivation for research on the first subject is the need for flexible and accurate production processes employing industrial robots as their main component. The challenge to overcome here is to achieve high-accuracy machining solutions, in spite of strong process forces affecting the robot end-effector. Because of the process forces, the nonlinear dynamics of the manipulator, such as the joint compliance and backlash, significantly degrade the achieved position accuracy of the machined part. In this thesis, a macro/micro manipulator configuration is considered to the purpose of increasing the position accuracy. In particular, a model-based control architecture is developed for control of the micro manipulator. The macro/micro manipulator configuration are validated by experimental results from milling tests in aluminium. The main result is that the proposed actuator configuration, combined with

the control architecture proposed in this thesis, can be used for increasing the accuracy of industrial machining processes with robots.

The interest for research on optimal control of road-vehicles in timecritical maneuvers is mainly driven by the desire to devise improved vehicle safety systems. Primarily, the solution of an optimal control problem for a specific cost function and model configuration can provide indication of performance limits as well as inspiration for control strategies in time-critical maneuvering situations. In this thesis, a methodology for solving this kind

of problems is discussed. More specifically, vehicle and tire modeling and the optimization formulation required to get useful solutions to these problems are investigated. Simulation results are presented for different vehicle models, under varying road-surface conditions, in aggressive maneuvers, where in particular the tires are performing at their limits. The obtained results are evaluated and compared. The main conclusion here is that even simplified road-vehicle models are able to replicate behavior observed when experienced drivers are handling vehicles in time-critical maneuvers. Hence, it is plausible that the results presented in this thesis provide a basis for development of future optimization-based driver assistance technologies. (Less)
Please use this url to cite or link to this publication:
author
supervisor
organization
publishing date
type
Thesis
publication status
published
subject
in
Research Reports TFRT-3259
pages
131 pages
publisher
Department of Automatic Control, Lund Institute of Technology, Lund University
ISSN
0280-5316
project
ProFlexa
COMET
SMErobotics
RobotLab LTH
language
English
LU publication?
yes
additional info
"month=April"
id
4d71a2bf-1a12-4d5f-97df-09e57d18de7c (old id 3633403)
date added to LUP
2016-04-01 12:53:38
date last changed
2024-06-04 15:07:09
@misc{4d71a2bf-1a12-4d5f-97df-09e57d18de7c,
  abstract     = {{Two main topics are considered in this thesis: Machining with industrial robots and optimal control of road-vehicles in critical maneuvers. The motivation for research on the first subject is the need for flexible and accurate production processes employing industrial robots as their main component. The challenge to overcome here is to achieve high-accuracy machining solutions, in spite of strong process forces affecting the robot end-effector. Because of the process forces, the nonlinear dynamics of the manipulator, such as the joint compliance and backlash, significantly degrade the achieved position accuracy of the machined part. In this thesis, a macro/micro manipulator configuration is considered to the purpose of increasing the position accuracy. In particular, a model-based control architecture is developed for control of the micro manipulator. The macro/micro manipulator configuration are validated by experimental results from milling tests in aluminium. The main result is that the proposed actuator configuration, combined with<br/><br>
the control architecture proposed in this thesis, can be used for increasing the accuracy of industrial machining processes with robots.<br/><br>
The interest for research on optimal control of road-vehicles in timecritical maneuvers is mainly driven by the desire to devise improved vehicle safety systems. Primarily, the solution of an optimal control problem for a specific cost function and model configuration can provide indication of performance limits as well as inspiration for control strategies in time-critical maneuvering situations. In this thesis, a methodology for solving this kind<br/><br>
of problems is discussed. More specifically, vehicle and tire modeling and the optimization formulation required to get useful solutions to these problems are investigated. Simulation results are presented for different vehicle models, under varying road-surface conditions, in aggressive maneuvers, where in particular the tires are performing at their limits. The obtained results are evaluated and compared. The main conclusion here is that even simplified road-vehicle models are able to replicate behavior observed when experienced drivers are handling vehicles in time-critical maneuvers. Hence, it is plausible that the results presented in this thesis provide a basis for development of future optimization-based driver assistance technologies.}},
  author       = {{Olofsson, Björn}},
  issn         = {{0280-5316}},
  language     = {{eng}},
  note         = {{Licentiate Thesis}},
  publisher    = {{Department of Automatic Control, Lund Institute of Technology, Lund University}},
  series       = {{Research Reports TFRT-3259}},
  title        = {{Topics in Machining with Industrial Robots and Optimal Control of Vehicles}},
  url          = {{https://lup.lub.lu.se/search/files/3031890/3633406.pdf}},
  year         = {{2013}},
}