QB Robotics qbmove Advanced Kit, Руководство пользователя

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28 aprile 2021
6.5.3.1 Launch file and URDF model
The .launch files included in qbchain package are built in a very similar way to the one reported
in Figure 6-13, and you can also inspect it by opening one of the files included in
“~/catkin_ws/src/qbchain
-ros/qb_cha
in_control/launch”
.
As mentioned before, these .launch files expect four qbmoves with IDs from 1 to 4 linked to the
specific kinematic structure URDF, and equip the chosen system with a dedicated ROS controller.
To launch one of the proposed robot configurations, you just need to execute the following
command from a terminal:
roslaunch qb_chain_control <
robot_config
>_control.launch standal
one:=true activate_on_initialization:=true
Where you need to replace < robot_config > with the name of the launch file, for example
delta_control.launch if you want to run the Delta robot configuration.
In addition, you can also enable the Waypoint control mode (by passing
`use_waypoints:=true` as additional argument in the previous command). The desired waypoints
must
be specified in the file qb
<robot_config>
_waypoints.yaml included in
“~/catkin_ws/src/qbchain
-ros/qb_chain_control/config
”
. The structure of these files will de
described in the next section.
IMPORTANT
It is worth noticing that this is just a state visualizer and not a simulator.
6.5.3.2 Dedicated controller
A specific Kit controller could have not been implemented since each single qbmove controller
can be exploited to control the whole system. Anyway, controlling a kinematic structure only
w.r.t. the joint space is not the best option for the end user.
For this reason, we have created the `qb_chain_controllers/KitKinematicController` (derived by
the official `controller_interface::Controller<hardware_interface::PositionJointInterface>`).
This C++ class is a
base class for the kinematic specific controller classes (that are
DeltaKinematicController , Arm1KinematicController , Arm2KinematicController ,
ArmV1KinematicController , ArmV2KinematicController , WristKinematicController ). The
appropriate controller is loaded automatically during startup, by selecting the correct .launch
file, and allows a more user-friendly approach.
Without digging too much into the C++ class implementation, which is publicly available under
`~/catkin_ws/src/qbchain-ros/qb_chain_controllers/` , the major improvements are the
followings:
•
By exploiting the direct and inverse kinematics of one of the proposed kinematic
structures, the user can control the end-effector position w.r.t. the cartesian space;