kindyn-doc.sgml

机器人开源项目orocos的源代码

 </term>
 <listitem>
  <para>
  idem, for (instantaneous) damping value.
  </para>
 </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="joint-vector-inverse-damping">
  <parameter>JointInverseDamping</parameter>: 
 </term>
 <listitem>
  <para>
  idem, for (instantaneous) inverse damping value.
  </para>
 </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="joint-vector-inertis">
  <parameter>JointInertia</parameter>: 
 </term>
 <listitem>
  <para>
  idem, for (instantaneous) inertia value.
  </para>
 </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="joint-vector-mobility">
  <parameter>JointMobility</parameter>, 
  <parameter>JointInverseInertia</parameter>: 
 </term>
 <listitem>
  <para>
  idem, for (instantaneous) mobility (= inverse inertia) value.
  </para>
 </listitem>
 </varlistentry>

</variablelist>

<variablelist>
<title>Kinematic chain dynamics</title>

 <varlistentry>
 <term>
  <anchor id="chain-inertia-matrix">
  <parameter>ChainInertiaMatrix</parameter>:
 </term>
 <listitem>
  <para>
  This is a square matrix, with a dimension equal to the number of
(actuated) joints in the kinematic chain. The matrix represents the
inertia of the total chain, as felt by each joint; i.e., element
<parameter>i,j</parameter> of the matrix is the force needed at joint
<parameter>i</parameter> to give joint <parameter>j</parameter> a unit
acceleration. (The exact meaning of a &rdquo;unit acceleration&rdquo;
depends on the physical units used for motion and inertia!)
  </para>
 </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="chain-damping-matrix">
  <parameter>ChainDampingMatrix</parameter>:
 </term>
 <listitem>
  <para>
  Idem, for damping.
  </para>
 </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="chain-stiffness-matrix">
  <parameter>ChainStiffnessMatrix</parameter>:
 </term>
 <listitem>
  <para>
Idem, for stiffness.
  </para>
 </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="chain-jacobian-matrix">
  <parameter>JacobianMatrix</parameter>:
 </term>
 <listitem>
  <para>
The 6 &times; N matrix that maps the N-dimensional coordinate vector
of joint velocities into one 6-dimensional end-effector
<link linkend="rigid-body-twist">twist</link>. Hence, the physical
interpration of each <emphasis>column</emphasis> of the Jacobian matrix is
as follows: the i-th column is the end-effector twist generated by applying
a unit joint velocity to the i-th joint and zero velocities to all other
joints.
  </para>
 </listitem>
 </varlistentry>

</variablelist>


<variablelist>
<title>Control classes</title>

 <varlistentry>
 <term>
  <anchor id="joint-vector-control-gains">
  <parameter>JointControlGain</parameter>:
 </term>
 <listitem>
  <para>
<emphasis>vector</emphasis> with scalar control gains,
<emphasis>i.e.</emphasis> for a SISO system that has one 
control loop for each joint, independently of the other joints.
  </para>
 </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="chain-control-gains">
  <parameter>ChainControlGain</parameter>:
 </term>
 <listitem>
  <para>
<emphasis>matrix</emphasis> of control gains, <emphasis>i.e.</emphasis> for
a MIMO system, in which the gains introduce coupling between the different
joints in the chain.
  </para>
 </listitem>
 </varlistentry>

</variablelist>

</section>


<section id="joint-physical-methods">
<title>Physical methods</title>

<para>
All the above-described entities are often mistaken for
&ldquo;vectors&rdquo;. However, they are not really members of a linear
vector space, but just an <emphasis>ordered collection</emphasis> of 1D
scalars. In addition, all the scalars in a coordinate vector need not have
the same physical units.
</para>
<para>
So, it is erroneous to provide method calls that would perform
<emphasis>geometric</emphasis> vector space operations. For
example, it is meaningless to take the &ldquo;vector in-product&rdquo; of
two <parameter>JointForce</parameter>, or look for the
&ldquo;vector&rdquo; that is &ldquo;orthogonal&rdquo; to a joint velocity
vector. The list of physically meaningful joint space method calls is
rather short:
<variablelist>
<title>Physical properties</title>
 <varlistentry>
 <term>
  <parameter>Add</parameter>:
 </term>
  <listitem>
   <para>
   two joint vectors (or joint-space matrices) of the same type can be added.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <parameter>Set</parameter>:
 </term>
  <listitem>
   <para>
the values of a joint vector (or a joint-space matrix) can be set to a
specific value. 
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <parameter>Get</parameter>:
 </term>
  <listitem>
   <para>
read the values of a joint vector (or a joint-space matrix). 
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <parameter>Scale</parameter>:
 </term>
  <listitem>
   <para>
every joint vector (or joint-space matrix) can be scaled by a
physically dimenionless scalar. Transformation with physically
non-dimensionless scalars has only physical meaning when the transformation
is done via the above-mentioned joint space or kinematic chain dynamics.
   </para>
  </listitem>
 </varlistentry>

</variablelist>

</para>

</section>

</section>


<section id="motor-space">
<title>
Motors and transmissions
</title>
<para>
The (actuated) joints of a robotic device are connected to motors,
often via a <emphasis role="strong">transmission</emphasis> that can
have non-ideal dynamical properties.  Hence, the discussion for the
<link linkend="joint-space">joints</link> can be completely
repeated for the <emphasis role="strong">motor</emphasis> and
<emphasis role="strong">transmission</emphasis> classes.
</para>
<para>
In addition, extra <parameter>JointToMotorTransmission</parameter> and
<parameter>MotorToJointTransmission</parameter> classes are needed, to
describe the transmission properties of the transmission between each
set of motor and joint axis. These are often constant floating
point numbers, but the <parameter>Set&hellip;</parameter> and
<parameter>Get&hellip;</parameter> methods could need more involved
calculations. For example, when the mapping between motors and
joints is not one-to-one, or when the transmission is non-ideal.
</para>

</section>


<section id="points-rigid-bodies-frames">
<title>Points, rigid bodies and frames</title>
<para>
This section describes the properties of the static and
dynamic relationships between &ldquo;motion&rdquo; and force, for
point masses as well as for rigid bodies. 
This text uses the term &ldquo;motion&rdquo; as a common shorthand for 
<emphasis role="strong">displacement</emphasis> and
its two derivatives <emphasis role="strong">velocity</emphasis> 
and <emphasis role="strong">acceleration</emphasis>.
When needed, it's straightforward to incorporate
<emphasis role="strong">small displacements</emphasis> (which have the
same properties as velocities, but other physical units) or
higher derivatives such as <emphasis>jerk</emphasis>.
</para>
<para>
The properties of the motion of
<emphasis role="strong">reference frames</emphasis> are completely the
same as the motion properties of rigid bodies; therefore, they are
treated in the same Section. A rigid body has some extra properties,
in the form of its <emphasis role="strong">dynamics</emphasis>.
</para>
<para>
This Section also regularly gives multiple names to the same software
classes; the reason is that all these names are used for the
same properties in different application contexts.
</para>

<section id="point-mass">
<title>Point mass</title>
<para>
<variablelist>
<title>Numeric coordinate representation:</title>

 <varlistentry>
 <term>
  <anchor id="point-mass-mass">
  <parameter>mass</parameter>:
 </term>
  <listitem>
   <para>
 floating point number.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="point-position">
  <parameter>PointPosition</parameter>, 
  <anchor id="point-velocity">
  <parameter>PointVelocity</parameter>,  
  <anchor id="point-acceleration">
  <parameter>PointAcceleration</parameter>,
  <anchor id="point-force">
  <parameter>PointForce</parameter>.
 </term>
  <listitem>
   <para>
These are all point vectors, connected to the moving point mass.
The point vector <emphasis>are</emphasis> real physical
vectors (<emphasis>i.e.</emphasis> members of a vector space), in contrast
to the joint-space coordinate &ldquo;vector;&rdquo;.
   </para>
  </listitem>
 </varlistentry>
</variablelist>

<variablelist>
<title>Physical properties:</title>
 <varlistentry>
 <term>
  <anchor id="point-mass-add-velocity">
  <parameter>add</parameter>,
  <parameter>set</parameter>,
  <parameter>get</parameter>,
  <parameter>scale</parameter>:
 </term>
  <listitem>
   <para>
   straightforward.
   </para>
  </listitem>
 </varlistentry>
</variablelist>

<variablelist>
<title>Symbolic properties:</title>
 <varlistentry>
 <term>
  <anchor id="point-mass-dimension">
  <parameter>dimension</parameter>:
 </term>
  <listitem>
   <para>
  1D, 2D, 3D.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
 <term>
  <anchor id="point-mass-units">
  <parameter>PointPhysicalUnits</parameter>:
 </term>
  <listitem>
   <para>
  gram, kilogram, meters/seconds, Newton, etc., depending on the type
of point vector. Note that all components in a point vector do have the
same physical units.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</para>

</section>


<section id="rigid-body-frame">
<title>Rigid body&mdash;Reference frame</title>
<para>
Most of the properties in this Section are common to rigid bodies and
reference frames; therefore, terminology of both contexts appears. A
rigid body has some extra properties, in the form of its
<emphasis>dynamics</emphasis>.
<variablelist>
<title>Numeric coordinate representations:</title>

 <varlistentry>
 <term>
  <anchor id="rigid-body-mass">
  <parameter>RigidBodyMass</parameter>:
 </term>
  <listitem>
   <para>
   the total mass of a rigid body.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="rigid-body-pose">
  <parameter>RigidBodyPose, RigidBodyPosition, BodyPose, Pose</parameter>:
 </term>
  <listitem>
   <para>
   the rigid body's position and orientation, with respect to a
&ldquo;world&rdquo; frame. This pose is defined by choosing a
<link linkend="rigid-body-reference-frame">RigidBodyReferenceFrame</link>
on the rigid body, and taking that frame's position and orientation. The
choice of this frame is arbitrary, and each of the following coordinate
entities has only meaning with respect to one well-defined frame.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="rigid-body-mass-matrix">
  <parameter>MassMatrix</parameter>, <parameter>InertiaMatrix</parameter>:
 </term>
  <listitem>
   <para>
the rigid body's inertia matrix, expressed in a known
<link linkend="rigid-body-reference-frame">RigidBodyReferenceFrame</link>
fixed to the rigid body. 
   </para>
   <para>
The dimensions of the matrix are
<parameter>N</parameter>-by-<parameter>N</parameter>, where
<parameter>N</parameter> is the 
<link linkend="rigid-body-dimension">dimension</link> of the space the rigid
body lives in; that is, 1, 2 or 3.
   </para>
  </listitem>
 </varlistentry>

 <varlistentry>
 <term>
  <anchor id="rigid-body-twist">
  <parameter> Twist, RigidBodyVelocity, FrameVelocity</parameter>:
 </term>
  <listitem>