# DefineKinematicPair

• A kinematic pair definition constrains the movement of the two links. This constraintment is defined by pinning local frames onto the two links ( blue- Local Link Reference Frame, red- Joint Markers) and specify the relative movement of these pinned frame with the type
• type is a String that specifies the type of the kinematic pair. Possible values values are as follows:
 Type Joint variable list "Rotational" {q1} "Translational" {x} "Cylindrical" {x,q2} "Universal" {q1,q2} "Spherical" {q1,q2,q3} "Planar" {x,y,q1} "Fixed" -
• link1 and link2 arguments are Strings, that specifies the name of the links. They can be specified either as full name or stripped name.
• All matrix arguments (mx1, mx2, LLRF1,LLRF2,mx) are 4x4 homogeneous transformation matrices.
• Each joint variable in {vars} should be defined as unique Symbol.
• The number of joint variables is equal to the relative degree of freedom of type kinematic pair.
• In case of loop closing kinematic pair definition DefineKinematicPair function calculate loop closure equation and appends to the \$LDDerivedParametersB record of linkage.
• In case of loop closing kinematic pair definition DefineKinematicPair function calculates the relative degree of freedom of the two links. It defines as many loop equation as the relative degree of freedom of the kinematic pair.
• The loop closure equations stored in the \$LDDerivedParametersB record. The loop closure kinematic pair definition will move n variable from the \$LDDrivingVariables record into \$LDDerivedParametersB record, where n is the number of loop closure equations. This reflects the change in the global degree of freedom of the linkage.
• In case of the kinematic pair is defined with Denavith-Hartenberg parameters, the LLRF markers of the corresponding links are placed automatically.
• With the Denavith-Hartenberg scenario only"Rotational" , "Translational" kinematic pair can be defined.
 JointName Automatic specifies the name of the kinematic pair in \$LDStructure record. JointLimits Automatic specifies any boolean expression that includes the joint variable. If the expression is evaluated true than the joint variables is within its limit. JointPose Automatic Additional tag for the joint variables that could be used for offsetting the joint variables. Parameters {} List of the simple parameters used in the kinematic pair's definition ( e.g {l0→10,l1→3} ). CandidateLoopVariables Automatic List of driving variable that will be used as loop variables in case of loop closing kinematic pair definition. LockingEnabled False Enables or disables kinematic pair definition that locks up the mechanism. AppendLinkGeometry Automatic Controls the genaration of geometric representations of the links in the kinematic pair. ConstraintEpsilon Automatic Error limit for accepting the constraint equations. ConstraintWorkingPrecision 16 Sets the working precision for the generated loop closing constraint equations. CheckRedundantEquations False Enables/disables the redundant equation checking. Verbose False Enables/disables verbose definition that prints log messages. SimplifyEquation True Enables/disables simplification of generated transformations and loop closing equations. ParameterInitialGuess Automatic Defines the initial guesses for loop variables in case of loop closing kinematic pair definition.