Determines a list of Denavit Hartenberg parameters and the corresponding coordinate systems from a list of revolute joint axes.
If static calibration is used the determined joint axes origins and points are determined in local coordinates to the coordinate systems of its corresponding joint axes.
The x- and z-Axes of the base coordinate system (and its origin) are determined by the general attribute „coordinateSystem“.
|name||String||name of the element||No|
|method||String||Different variants of Denavit Hartenberg parameterisation exists. The most used one named „distal“ and defines the coordinate systems at the distal end of the segments. The x-axes of the the corresponding coordinate systems are upright to both adjusting joint axes. An importend variant is named as „modified“. Its x-axes are upright only to one of the two adjoining joint axes. The default method is „distal“ and is used if to method is explicitly defined by usage this attribute.||Yes|
|xAxesDirections||Comma separated list of Strings||List of x-axis direction expressions.||No|
|jointAxes||Comma seperated List of Strings||List of joint axes element names. Die position of the first axis is used as origin of the base coordinate system.||No|
|calibrateIncludes||name of a switch||Name of a switch to define the static calibration trial with the normal pose of the robot arm||Yes|
|nominalD||Comma seperated list of double values >=0, NaN included||Used for method=„modified“ only. List of nominal values useful to set to values >=0 for nearly parallel joint axes. There exist no d0-value. In consequence the list has minus one elements compared with the count of joint-axes. Set values to „NaN“ if the corresponding axes are not nearly parallel which allows automated determination of the d-value.||Yes|
|lastD||double||Used for classical Denavit Hartenberg method only. Defines the last d parameter. This parameter can not be estimated. It is assumed that the last coordinate system the CS of the TCP has the same z-direction as the last joint axis (r==0, alpha==0). The parameter d is the translation of the origin of the last joint axis in direction of this axis. If the parameter is not set it is automatically set to (0d,0d,0d) but a warning is written into the log.||Yes|
|signR||Comma seperated list of boolean values „true“ or „false“||Used for method=„modified“ only. This allows to switch the sign of r-vector, default should be false||Yes|
|distal||The default method, also called as classical method. This defines coordinate systems at the distal end of the links and the x-axes are orthogonal to both adjacent joint-axes.|
|modified||The modified version of the Denavit Hartenberg parameterisation defines coordinate systems at the proximal side of the links. The x-axes are orthogonal only to its corresponding coordinate system (joint axis).|
|<name>Alpha<Index>||Double||alpha (twist angle) in [deg]|
|<name>Theta<Index>||Double||theta (joint angle) in [deg]|
|<name>D<Index>||Double||d (displacement or link offset) in [mm]|
|<name>R<Index>||Double||r (link length) in [mm]|
|<name>O<Index>||Vector3d||Origin of the Denavit Harteberg based coordinate system.|
|<name>P<Index>||Vector3d||Endpoint of the previous x-axis on the z-axis.|
<DH name="DHSARA" method="modified" xAxesDirections="GlobeX,BaseX,ShoulderX,ElbowX,Wrist1X,Wrist2X,TCPX" jointAxes="GlobeZ,BaseAxisSARA,ShoulderAxisSARA,ElbowAxisSARA,WristAxis1SARA,WristAxis2SARA,TCPAxisSARA" calibrateIncludes="static_calibrate1" nominalD="NaN, 0.0, 0.0, NaN, NaN, 0.099381832"/>
The mean/std values of the following table are calculated, if the attribute „phase“ is set and also the attribute average=„true“ or meanStd=„true“. If the last attribute is set than also the corresponding std-values are calculated. All values are are based on mean-values for each phase. These mean-values are averaged and also the std for this mean is determined.
|<name>Alpha<Index>PhasesMean||Double||alpha in [deg]; for each phase the mean is calculated; than the mean of all of these values is determined.|
|<name>Alpha<Index>PhasesStd||Double||For each phase the mean is calculated; than the mean of all of these values is determined and the std of this mean is determined.|
|<name>Theta<Index>PhasesMean||Double||theta in [deg]; for each phase the mean is calculated; than the mean of all of these values is determined.|
|<name>Theta<Index>PhasesStd||Double||theta in [deg]; for each phase the mean is calculated; than the mean of all of these values is determined and the std of this mean is determined.|
|<name>D<Index>PhasesMean||Double||D in [mm]; for each phase the mean is calculated; than the mean of all of these values is determined.|
|<name>D<Index>PhasesStd||Double||std for each phase the std is calculated; than the mean of all of these values is determined and the std of this mean is determined.|
|<name>R<Index>PhasesMean||Double||R in [mm]; for each phase the mean is calculated; than the mean of all of these values is determined.|
|<name>R<Index>PhasesStd||Double||R in [mm]; for each phase the mean is calculated; than the mean of all of these values is determined and the std of this mean is determined.|
This element defines a cartesian coordinate system based on a parent coordinate system and Denavit-Hartenberg parameters.
|name||Name of the element||Yes|
|referenceCoordinateSystem||Defines the the reference coordinate system by its name.||Yes|
|<name>||Matrix3d||Representation of the three orthogonal orientation axes of the determined local coordinate system (columns of the matrix)|
|<name>Position||Vector3d||Origin of the coordinate system|
<ForwardKinematicDH name="BaseUR" referenceCoordinateSystem="GLOBE" Alpha="0.5" Theta="Angle0" D="0.145" R="0.234"/>
An alternative to use this element is to use the corresponding function:
<CoordinateSystem name="BaseUR" Pose="dhm(Angle0, DH_alpha0, DH_d0, DH_r0)"/>