How to use a model without joint

[lrapetti]

Summary

I was planning to use the WB-toolbox in order to retrieve kinematics and dynamics of a single rigid body model (i.e. a model without joints) in order to exploit kindyncomputation.

I am experiencing however some problems, and I guess more problem will arise moving further.

The current limitation I found at this stage is the following:

• If I initialize the Config as:

  WBTConfigBox           = WBToolbox.Configuration;
  WBTConfigBox.RobotName = 'box';
  WBTConfigBox.UrdfFile  = 'box_idyn.urdf';
  WBTConfigBox.LocalName = 'WBT';
  % Controlboards and joints list. Each joint is associated to the corresponding controlboard 
  WBTConfigBox.ControlBoardsNames     = {};
  WBTConfigBox.ControlledJoints       = {};
  

  When I run the model, simulink fails reporting the following error

  Error evaluating 'InitFcn' callback of SubSystem block (mask) 'CollaborativeErgonomyControl/Subsystem/Configuration'. 
  Callback string is 'source = get_param(gcb,'ConfigSource');
  
  if strcmp(source, 'Workspace')
      object = get_param(gcb,'ConfigObject');
      WBToolbox.ConfigurationToMask(gcb, object);
  end
  
  WBToolbox.MaskToConfiguration(gcb);
  
  clear object source'
  Caused by:
  [MaskToConfiguration] The provided config is NonValid.
  

  It seems then that teh fields ControlBoardsNames and ControlledJoints, that are left as empty cell, are seen as NonValid default string.

• I have then tried to put some empty string in that two fields

  WBTConfigBox           = WBToolbox.Configuration;
  WBTConfigBox.RobotName = 'box';
  WBTConfigBox.UrdfFile  = 'box_idyn.urdf';
  WBTConfigBox.LocalName = 'WBT';
  % Controlboards and joints list. Each joint is associated to the corresponding controlboard 
  WBTConfigBox.ControlBoardsNames     = {''};
  WBTConfigBox.ControlledJoints       = {''};
  

  but then blockfactory fails because the joint can not be found

   Possible causes: file not found, or the joint list contains an entry not present in the urdf model.
  Failed to initialize the KinDynComputations object.
  Cannot retrieve handle to KinDynComputations.
  

[lrapetti]

Moreover, I am wondering what should be given as input to the blocks where the joint configuration is required.