Modelica.Mechanics.MultiBody.Examples.Systems.RobotR3

Information

This package contains models of the robot r3 of the company Manutec. These models are used to demonstrate in which way complex robot models might be built up by testing first the component models individually before composing them together. Furthermore, it is shown how CAD data can be used for animation.

The following models are available:

   oneAxis   Test one axis (controller, motor, gearbox).
   fullRobot Test complete robot model.

The r3 robot is no longer manufactured. In fact the company Manutec does no longer exist. The parameters of this robot have been determined by measurements in the laboratory of DLR. The measurement procedure is described in:

   Tuerk S. (1990): Zur Modellierung der Dynamik von Robotern mit
       rotatorischen Gelenken. Fortschrittberichte VDI, Reihe 8, Nr. 211,
       VDI-Verlag 1990.

The robot model is described in detail in

   Otter M. (1995): Objektorientierte Modellierung mechatronischer
       Systeme am Beispiel geregelter Roboter. Dissertation,
       Fortschrittberichte VDI, Reihe 20, Nr. 147, VDI-Verlag 1995.
       This report can be downloaded as compressed postscript file
       from: http://www.robotic.dlr.de/Martin.Otter.

The path planning is performed in a simple way by using essentially the Modelica.Mechanics.Rotational.KinematicPTP block. A user defines a path by start and end angle of every axis. A path is planned such that all axes are moving as fast as possible under the given restrictions of maximum joint speeds and maximum joint accelerations. The actual r3 robot from Manutec had a different path planning strategy. Todays path planning algorithms from robot companies are much more involved.

In order to get a nice animation, CAD data from a KUKA robot is used, since CAD data of the original r3 robot was not available. The KUKA CAD data was derived from public data of KUKA available at: http://www.kuka-roboter.de/english/produkte/cad/low_payloads.html. Since dimensions of the corresponding KUKA robot are similar but not identical to the r3 robot, the data of the r3 robot (such as arm lengths) have been modified, such that it matches the CAD data.

In this model, a simplified P-PI cascade controller for every axes is used. The parameters have been manually adjusted by simulations. The original r3 controllers are more complicated. The reason to use simplified controllers is to have a simpler demo.

Package Content

Name	Description
oneAxis	Model of one axis of robot (controller, motor, gearbox) with simple load
fullRobot	6 degree of freedom robot with path planning, controllers, motors, brakes, gears and mechanics
Components	Library of components of the robot

Modelica.Mechanics.MultiBody.Examples.Systems.RobotR3.oneAxis

Information

With this model one axis of the r3 robot is checked. The mechanical structure is replaced by a simple load inertia.

Parameters

Name	Description
mLoad	Mass of load [kg]
kp	Gain of position controller of axis 2
ks	Gain of speed controller of axis 2
Ts	Time constant of integrator of speed controller of axis 2 [s]
startAngle	Start angle of axis 2 [deg]
endAngle	End angle of axis 2 [deg]
swingTime	Additional time after reference motion is in rest before simulation is stopped [s]
refSpeedMax	Maximum reference speed [rad/s]
refAccMax	Maximum reference acceleration [rad/s2]

Modelica.Mechanics.MultiBody.Examples.Systems.RobotR3.fullRobot

Information

This is a detailed model of the robot. For animation CAD data is used. Translate and simulate with the default settings (default simulation time = 3 s). Use command script "modelica://Modelica/Resources/Scripts/Dymola/Mechanics/MultiBody/Examples/Systems/fullRobotPlot.mos" to plot variables.

Parameters

Name	Description
mLoad	Mass of load [kg]
rLoad[3]	Distance from last flange to load mass [m]
g	Gravity acceleration [m/s2]
refStartTime	Start time of reference motion [s]
refSwingTime	Additional time after reference motion is in rest before simulation is stopped [s]
Reference
startAngles
startAngle1	Start angle of axis 1 [deg]
startAngle2	Start angle of axis 2 [deg]
startAngle3	Start angle of axis 3 [deg]
startAngle4	Start angle of axis 4 [deg]
startAngle5	Start angle of axis 5 [deg]
startAngle6	Start angle of axis 6 [deg]
endAngles
endAngle1	End angle of axis 1 [deg]
endAngle2	End angle of axis 2 [deg]
endAngle3	End angle of axis 3 [deg]
endAngle4	End angle of axis 4 [deg]
endAngle5	End angle of axis 5 [deg]
endAngle6	End angle of axis 6 [deg]
Limits
refSpeedMax[6]	Maximum reference speeds of all joints [rad/s]
refAccMax[6]	Maximum reference accelerations of all joints [rad/s2]
Controller
Axis 1
kp1	Gain of position controller
ks1	Gain of speed controller
Ts1	Time constant of integrator of speed controller [s]
Axis 2
kp2	Gain of position controller
ks2	Gain of speed controller
Ts2	Time constant of integrator of speed controller [s]
Axis 3
kp3	Gain of position controller
ks3	Gain of speed controller
Ts3	Time constant of integrator of speed controller [s]
Axis 4
kp4	Gain of position controller
ks4	Gain of speed controller
Ts4	Time constant of integrator of speed controller [s]
Axis 5
kp5	Gain of position controller
ks5	Gain of speed controller
Ts5	Time constant of integrator of speed controller [s]
Axis 6
kp6	Gain of position controller
ks6	Gain of speed controller
Ts6	Time constant of integrator of speed controller [s]