classRR

RR Mechanism

Extends from Servomechanisms.Utilities.IconNameB.

Information

General

This class models a 2R mechanism. It is intended to be used as a RR planar mechanism also known as planar elbow manipulator.

Implementation

It uses RLink element and it's based on the next scheme:

Notes

The first joint is fixed in the origin.
By default the joint axis is the z axis (rotation axis in direction
```
n=[0,0,1]
```
) and gravity is in direction
```
n=[0,-1,0]
```
The generalized coordinates theta1 and theta2 are the angles of each joint in radians as shown in the figure.
The interfaces are Modelica.Mechanics.Rotational
The mechanical parameters of each link are editable (dimensions, mass, etc)
The World element is included in the model.

Parameters

Type	Name	Default	Description
String	shape1	"box"	shape of visualizer:"shape", "box", "cylinder"
Modelica.Mechanics.MultiBody.Types.Axis	n1	{0, 0, 1}	Axis of rotation resolved in frame_a (= same as in frame_b)
String	shape2	"box"	shape of visualizer:"shape", "box", "cylinder"
Modelica.Mechanics.MultiBody.Types.Axis	n2	{0, 0, 1}	Axis of rotation resolved in frame_a (= same as in frame_b)
SI.Acceleration	g	9.81	Constant gravity acceleration
if shape
SI.Position[3]	r1		Vector from frame_a to frame_b resolved in frame_a
SI.Position[3]	r_CM1		Vector from frame_a to center of mass, resolved in frame_a
SI.Mass	m1		Mass of rigid body
SI.Length	shapeLength1	1
SI.Distance	shapeWidth1	boxLength1/20
SI.Distance	shapeHeight1	boxWidth1
String	shapeType1	"modelica://Servomechanisms//Resources//b2.dxf"	Type of shape
Real	extra1	1	Additional parameter depending on shapeType (see docu of Visualizers.Advanced.Shape)
SI.Position[3]	r2		Vector from frame_a to frame_b resolved in frame_a
SI.Position[3]	r_CM2		Vector from frame_a to center of mass, resolved in frame_a
SI.Mass	m2		Mass of rigid body
SI.Length	shapeLength2	1
SI.Distance	shapeWidth2	boxLength2/20
SI.Distance	shapeHeight2	boxWidth2
String	shapeType2	"modelica://Servomechanisms//Resources//b2.dxf"	Type of shape
Real	extra2	1	Additional parameter depending on shapeType (see docu of Visualizers.Advanced.Shape)
if shape › Inertia tensor (resolved in center of mass, parallel to frame_a)
SI.Inertia	I_111	0.001	(1,1) element of inertia tensor
SI.Inertia	I_221	0.001	(2,2) element of inertia tensor
SI.Inertia	I_331	0.001	(3,3) element of inertia tensor
SI.Inertia	I_211	0	(2,1) element of inertia tensor
SI.Inertia	I_311	0	(3,1) element of inertia tensor
SI.Inertia	I_321	0	(3,2) element of inertia tensor
SI.Inertia	I_112	0.001	(1,1) element of inertia tensor
SI.Inertia	I_222	0.001	(2,2) element of inertia tensor
SI.Inertia	I_332	0.001	(3,3) element of inertia tensor
SI.Inertia	I_212	0	(2,1) element of inertia tensor
SI.Inertia	I_312	0	(3,1) element of inertia tensor
SI.Inertia	I_322	0	(3,2) element of inertia tensor
if box
SI.Length	boxLength1	1
SI.Distance	boxWidth1	boxLength1/20
SI.Distance	boxHeight1	boxWidth1
SI.Length	boxLength2	1
SI.Distance	boxWidth2	boxLength2/20
SI.Distance	boxHeight2	boxWidth2
if cylinder
SI.Length	cylinderLength1	1
SI.Distance	cylinderDiameter1	cylinderLength1/20
SI.Length	cylinderLength2	1
SI.Distance	cylinderDiameter2	cylinderLength2/20
Parameters only for cylinder and box
SI.Density	density1	7700	Density of link (e.g., steel: 7700 .. 7900, wood : 400 .. 800)
SI.Density	density2	7700	Density of link (e.g., steel: 7700 .. 7900, wood : 400 .. 800)

Connectors

Type	Name	Default	Description
Modelica.Mechanics.Rotational.Interfaces.Flange_a	flange_rotational1
Modelica.Mechanics.Rotational.Interfaces.Flange_a	flange_rotational2

Components

Type	Name	Default	Description
Servomechanisms.Mechanism.RLink	rotational2
Servomechanisms.Mechanism.RLink	rotational1
Modelica.Mechanics.MultiBody.Parts.Fixed	fixed1