Users Manual

Table 7.1.1: The rc
_
slam component’s run-time parameters
Name Type Min Max Default Description
autorecovery bool False True True In case of fatal errors recover corrected position
and restart mapping
halt
_
on
_
low
_
memory bool False True True When the memory runs low, go to halted state
This component reports the following status values.
Table 7.1.2: The rc
_
slam component’s status values
Name Description
map
_
frames Number of frames that constitute the map
state The current state of the rc_slam node
trajectory
_
poses Number of poses in the estimated trajectory
The reported state can take one of the following values.
Table 7.1.3: Possible states of the rc
_
slam component
State name Description
IDLE The component is ready, but idle. No trajectory data is available.
WAITING_FOR_DATA The component was started but is waiting for data from stereo INS or VO.
RUNNING The component is running.
HALTED The component is stopped. The trajectory data is still available. No new information is processed.
RESETTING The component is being stopped and the internal data is being cleared.
RESTARTING The component is being restarted.
FATAL A fatal error has occured.
7.1.4 Services
The SLAM component offers the following services.
Note: Activation and deactivation of the SLAM component is done via the service interface of rc_dynamics
(see Services, Section 6.3.3).
reset clears the internal state of the SLAM component. This service is to be used after stopping the SLAM com-
ponent using the rc_dynamics interface (see the respective Services, Section 6.3.3). The SLAM component
maintains the estimate of the full trajectory even when stopped. This service clears this estimate and frees
the respective memory. The returned status is RESETTING.
This service requires no arguments.
This service returns the following response:
{
"accepted": "bool",
"current
_
state": "string"
}
get
_
trajectory With this service call the trajectory can be retrieved. The service arguments allow to select a
subsection of the trajectory by defining a start
_
time and an end
_
time. Both are optional, i.e., they could
be left empty or filled with zero values, which results in the subsection to include the trajectory from the
very beginning, or to the very end, respectively, or both. If not empty or zero, they can be defined either as
absolute timestamps or to be relative to the trajectory (start
_
time
_
relative and end
_
time
_
relative
flags). If defined to be relative, the values’ signs indicate to which point in time they relate to: Positive
values define an offset to the start time of the trajectory; negative values are interpreted as an offset from the
end time of the trajectory. The below diagram illustrates three examples for the relative parameterization.
7.1. SLAM 69