<p>Atlas Copco Surface Drilling Equipment is one of the leading manufacturers of surface drill rigs. To stay in the top segment it is of great importance to have a well functioning development strategy as well as rig functions that makes the work as easy as possible for the operator. In this master thesis one development strategy has been evaluated and a dub tip control has been developed from idea to test on rig.</p><p> </p><p>Today the conventional method to position the drill is to use two joysticks with three axes each where each axis corresponds to one hydraulic actuator on the boom and feeder structure. The dub tip control system enables the operator to position the drill in Cartesian coordinates with only one 3-axes joystick. After the definition of the desired drill angle is done, the control system makes sure that this angle is obtained throughout the positioning motion. This system makes it considerably easier for an inexperienced operator to position the drill.</p><p> </p><p>For development, simulation and verification of the control algorithms and regulators <em>Matlab/Simulink</em> has been used. To test the control system on rig, a configuration with <em>LabVIEW</em> together with a <em>compactDAQ</em> has been evaluated. <em>LabVIEW </em>is chosen because it provides the opportunity to create a user friendly graphical user interface. To use this configuration is however not recommended for persons with little or none experience from using <em>LabVIEW</em>.</p><p> </p><p>This development strategy can be used for tests and verifications of control algorithms, but since neither <em>Windows </em>nor the <em>compactDAQ </em>are real time systems, there are solutions that are better but of course to a higher price.</p><p> </p><p>The master thesis work has shown that it is possible to implement a dub tip control on a rig of this dimension. It has also concluded that compensated valves are necessary to achieve optimal performance of a velocity controlled dub tip positioning.</p>

Atlas Copco Surface Drilling Equipment is one of the leading manufacturers of surface drill rigs. To stay in the top segment it is of great importance to have a well functioning development strategy as well as rig functions that makes the work as easy as possible for the operator. In this master thesis one development strategy has been evaluated and a dub tip control has been developed from idea to test on rig.   Today the conventional method to position the drill is to use two joysticks with three axes each where each axis corresponds to one hydraulic actuator on the boom and feeder structure. The dub tip control system enables the operator to position the drill in Cartesian coordinates with only one 3-axes joystick. After the definition of the desired drill angle is done, the control system makes sure that this angle is obtained throughout the positioning motion. This system makes it considerably easier for an inexperienced operator to position the drill.   For development, simulation and verification of the control algorithms and regulators Matlab/Simulink has been used. To test the control system on rig, a configuration with LabVIEW together with a compactDAQ has been evaluated. LabVIEW is chosen because it provides the opportunity to create a user friendly graphical user interface. To use this configuration is however not recommended for persons with little or none experience from using LabVIEW.   This development strategy can be used for tests and verifications of control algorithms, but since neither Windows nor the compactDAQ are real time systems, there are solutions that are better but of course to a higher price.   The master thesis work has shown that it is possible to implement a dub tip control on a rig of this dimension. It has also concluded that compensated valves are necessary to achieve optimal performance of a velocity controlled dub tip positioning.

The objective of this thesis is to develop a model that represents the dynamics of a hydraulically operated forestry crane. The model was derived with the traditional Euler-Lagrange formalism and considers the crane mechanics, three double-acting hydraulic cylinders and the valve control unit. On the basis of the derived model we reproduced the entire crane model in MATLAB in order to run simulations herewith. This gave us the possibility to do parameter changes for further studies of the crane in motion. Another major goal within the thesis work was to estimate cylinder friction of the hydraulic actuators. We built up a test rig and used double-acting cylinders for determing their frictional behaviour. For this, we ran open-loop experiments in order to create velocity-friction maps that represented the static friction force of the cylinders. In this concern, we varied system pressure and cylinder load to study their influence on the friction force. By means of the derived static friction maps we approached the cylinder’s dynamic friction behaviour and applied both step and ramp control inputs to examine the spring-damping characteristics of the microspoic bristles in the contacting area. The dynamic friction experiments have been exerted in the fashion of the LuGre model. As a result we acquired different nominal friction parameters that we necessarily used to develope adequate friction models. A third objective of this thesis was to establish a crane-tip control. Instead of a traditional control, providing a direct relationship between joystick input and cylinder extension, the focus was to build up a control for the end-effector’s trajectory in a two-dimensional frame. This could be achieved by using inverse kinematics in order to determine the required joint angles that corresponded to the desired position of the crane-tip. The work also contains a CD including all developed MATLAB models that have been written within this project.

Det här rapporten är en del av mitt examensarbete för högskoleingenjörsexamen i elektroteknik vid Växjö Universitet, MSI. Arbetet är en del av ett större projekt kallat Kranstyrningsprojektet som bedrivs av Växjö Universitet, Rottne Industri med flera, vars syfte är att underlätta för förare att kontrollera den kran som finns på Rottnes skotare. För projektet har det använts en laborationskran och nu har önskemålet varit att det till kranen ska installeras ett nytt styrsystem från dSPACE. Dessutom vill man att nya givare ska sättas på kranen och kopplas till dSPACE. Man vill även ha en manual för att nya studenter ska kunna använda systemet. Det nya dSPACE-systemet består av en datorlåda med processor- och I/O-kort. Man kommunicerar med dSPACE från en PC. Arbetet med installationen har stött på flera problem och arbetet har dragit ut på tiden. När systemet till slut gick att använda utfördes ett par tester och sen implementerades det på kranen. Arbete med att ta fram underlag för installation av accelerometrar på kranen pågick samtidigt och en jämförelse mellan olika alternativ gjordes. Arbetet resulterade i att laborationskranen nu går att styra med det nyinköpta systemet från dSPACE och en manual skapades för att underlätta användandet av systemet. / This document is a part of my bachelor degree thesis in electronic engineering was done at Växjö University, MSI. This work is a part of a bigger project called Crane Tip Control which is pursued by Växjö University, Rottne Industri and others, whose purpose is to facilitate for drivers to control the crane used on forwarders from Rottne. For this project, a laboratory crane has been used and they requested that a new control system from dSPACE was installed to the crane. Also they want new sensors to be placed on the crane and connected to dSPACE. A manual should also be created for new students who want to use the system. The new dSPACE-system consists of a computer box with processor- and I/O-boards. Communication with dSPACE is done via a PC. The work with the installation has encountered many problems and the work has been overrun. When the system finally was working, some tests were performed and then the system was installed at the crane. A task to assemble data for installation of accelerometers, was done during the same time and a comparison between different alternatives was made. The work resulted in the laboratory crane is now able to be controled by the new dSPACE-system and a manual was created to facilitate the usage of the system.

<p>The objective of this thesis is to develop a model that represents the dynamics of a hydraulically operated forestry crane. The model was derived with the traditional Euler-Lagrange formalism and considers the crane mechanics, three double-acting hydraulic cylinders and the valve control unit. On the basis of the derived model we reproduced the entire crane model in MATLAB in order to run simulations herewith. This gave us the possibility to do parameter changes for further studies of the crane in motion.</p><p>Another major goal within the thesis work was to estimate cylinder friction of the hydraulic actuators. We built up a test rig and used double-acting cylinders for determing their frictional behaviour. For this, we ran open-loop experiments in order to create velocity-friction maps that represented the static friction force of the cylinders. In this concern, we varied system pressure and cylinder load to study their influence on the friction force. By means of the derived static friction maps we approached the cylinder’s dynamic friction behaviour and applied both step and ramp control inputs to examine the spring-damping characteristics of the microspoic bristles in the contacting area. The dynamic friction experiments have been exerted in the fashion of the LuGre model. As a result we acquired different nominal friction parameters that we necessarily used to develope adequate friction models.</p><p>A third objective of this thesis was to establish a crane-tip control. Instead of a traditional control, providing a direct relationship between joystick input and cylinder extension, the focus was to build up a control for the end-effector’s trajectory in a two-dimensional frame. This could be achieved by using inverse kinematics in order to determine the required joint angles that corresponded to the desired position of the crane-tip.</p><p>The work also contains a CD including all developed MATLAB models that have been written within this project.</p>

<p>Det här rapporten är en del av mitt examensarbete för högskoleingenjörsexamen i elektroteknik vid Växjö Universitet, MSI. Arbetet är en del av ett större projekt kallat Kranstyrningsprojektet som bedrivs av Växjö Universitet, Rottne Industri med flera, vars syfte är att underlätta för förare att kontrollera den kran som finns på Rottnes skotare. För projektet har det använts en laborationskran och nu har önskemålet varit att det till kranen ska installeras ett nytt styrsystem från dSPACE. Dessutom vill man att nya givare ska sättas på kranen och kopplas till dSPACE. Man vill även ha en manual för att nya studenter ska kunna använda systemet. Det nya dSPACE-systemet består av en datorlåda med processor- och I/O-kort. Man kommunicerar med dSPACE från en PC. Arbetet med installationen har stött på flera problem och arbetet har dragit ut på tiden. När systemet till slut gick att använda utfördes ett par tester och sen implementerades det på kranen. Arbete med att ta fram underlag för installation av accelerometrar på kranen pågick samtidigt och en jämförelse mellan olika alternativ gjordes. Arbetet resulterade i att laborationskranen nu går att styra med det nyinköpta systemet från dSPACE och en manual skapades för att underlätta användandet av systemet.</p> / <p>This document is a part of my bachelor degree thesis in electronic engineering was done at Växjö University, MSI. This work is a part of a bigger project called Crane Tip Control which is pursued by Växjö University, Rottne Industri and others, whose purpose is to facilitate for drivers to control the crane used on forwarders from Rottne. For this project, a laboratory crane has been used and they requested that a new control system from dSPACE was installed to the crane. Also they want new sensors to be placed on the crane and connected to dSPACE. A manual should also be created for new students who want to use the system. The new dSPACE-system consists of a computer box with processor- and I/O-boards. Communication with dSPACE is done via a PC. The work with the installation has encountered many problems and the work has been overrun. When the system finally was working, some tests were performed and then the system was installed at the crane. A task to assemble data for installation of accelerometers, was done during the same time and a comparison between different alternatives was made. The work resulted in the laboratory crane is now able to be controled by the new dSPACE-system and a manual was created to facilitate the usage of the system.</p>