QBSOFTHAND RESEARCH USER MANUAL —
33
2. Waypoint Control
This control mode is a bit more structured and useful than the previous: it allows to set a fixed trajectory
of any number of position waypoints (with timing constraints) and set the robot to cycle infinitely on it
(because of the loop it is recommended to set the first and last waypoint in a similar configuration to
avoid unwanted sudden changes).
To start this mode just add
use_waypoints:=true
to the general
roslaunch
command (be sure that
the opposite
use_controller_gui
is not used). You won't see any control interface in this case but the
qb SoftHand
should start moving according to the given trajectory, parsed from a yaml file located at
<robot_package>_control/config/<robot_name>_waypoints.yaml
where
robot_name
and
robot_package
are two additional launch file arguments.
Customization
You can modify the waypoint trajectory to replicate the behavior you want: either change the
<robot_package>_control/config/<robot_name>_waypoints.yaml
or add another custom
application-specific file in the
config
directory. In the second case you need to set the argument
robot_name
properly when launching the command from the terminal.
The waypoint configuration is as follows:
# Waypoints describe the desired motion trajectory:
# - time [s]: can be either a single value or an interval
for
which joint_positions hold
# - joint_positions:
# - hand closure [
0
,
1
];
# - joint_velocities: optional, use it only
if
you want a nonzero value
# - hand closure [
0
,
1
]/s;
# - joint_accelerations: optional, use it only
if
you want a nonzero value
# - hand closure [
0
,
1
]/s^
2
;
#
# It is worth noting that,
if
specified, joint_positions, joint_velocities and joint_accelerations must be of size one.
waypoints:
-
time: [
1.0
]
joint_positions:
<device_name>: [
0.0
]
-
time: [
2.25
,
2.75
]
joint_positions:
<device_name>: [
0.8
]
-
time: [
4.0
]
joint_positions:
