QB Robotics qbmove Advanced Kit User Manual page 91

•
the 3D positioning of the end-effector can be more or less compliant to the
surrounding environment by adjusting the stiffness of the three joints. This leads
respectively to a less or more precise pursuing of the control reference, but the
compliance can be exploited to achieve many tasks that could not have been done
otherwise;
•
the end-effector qbmove can be treated as a two-finger gripper with the advantage of
exploiting the positioning and compliance control proper of qbmove devices. Indeed,
the grip can be more or less strong w.r.t. the applied stiffness.
•
You can quickly implement other desired kinematics with new classes derived from
KitKinematicController. You just need closed form solutions for forward and inverse
kinematic of the configuration that you desire (examples of how to do this can be
found in
DeltaKinematicController), or exploit the potentials of KDL (http://wiki.ros.org/kdl)
and trac_ik
ArmV2KinematicController, Arm2KinematicController and WristKinematicController.
6.5.3.3 Interact with robots
Currently it is possible to interact with robot in three different ways.
1. Publishing messages in a specific topic
In this case you have to specify:
•
The end-effector desired position to reach;
•
each qbmove stiffness;
•
the velocity with which the robot has to move. This is a scalar parameter from
0.1 to 1 and it specify the time that the robot takes to reach the desired
target position (0.1 correspond to 10 s, 1 to 1 s);
•
the type of movement(moveL or moveJ). moveL moves the end-effector in
Cartesian space by describing a linear segment, moveJ moves the end-
effector to the target position without considering intermediate poses.
IMPORTANT
According to the above, in order to interact with a kinematic configuration, e.g. Arm
V1, you can open a new terminal tab while the corresponding node is running, and
execute the command:
rostopic pub /qbarm_v1/control/arm_v1_controller/target_poses qb
_chain_msgs/MoveChain "
target_pose:
header:
seq: 0
stamp:
secs: 0
ArmV1KinematicController,
(http://wiki.ros.org/trac_ik).
moveL movement modality is not always possible. There could be target
positions that cannot be reached by moving linearly from some starting
poses.
Arm1KinematicController
These tools are
28 aprile 2021
and
exploited in
88