Keeping The Beat-Pulse; Closing The Connection-Close; Movement Commands - Pioneer 2 / PeopleBot Operation Manual

Pioneer 2 Operating System
housekeeping functions, start its sonar and motor controllers (among other things), listen
for client commands, and begin transmitting server information to the client.
Note that once connected, Pioneer 2's and PeopleBot's motors are disabled, regardless
of their state when last connected. After starting a connection, you must either enable
the motors manually (white MOTORS button) or send the P2OS motors ENABLE command
with the argument 1; sfRobotComInt(4,1), for example.
Keeping the Beat—PULSE
A P2OS safety watchdog expects that the controller receives at least one
communication packet from the client every watchdog seconds (default is two).
Otherwise, it assumes the client-server connection is broken and stops the robot.
It's good practice to have the client send a PULSE command just after opening the P2OS
servers. And if your client application will be otherwise distracted for some time,
periodically issue the PULSE command to let P2OS know you are indeed alive and well.
If the robot shuts down due to lack of communications traffic, it will revive upon receipt
of a client command and automatically accelerate to the last-specified speed and
heading setpoints.
Closing the Connection—CLOSE
To close the client-server connection, disabling the motors and sonar, and resetting P2OS
to its wait state, simply issue the client CLOSE command.

Movement Commands

The P2OS motor-control
servers accept
different motion
mands of two mutually
exclusive types:
direct wheel-velocities or
translational/rotational
motor controls. The robot
servers automatically
abandon any
translational or rotational
setpoints and switch to
direct wheel-velocity
control mode when they
receive a VEL2 command.
Any other
command makes
abandon direct
velocity control.
For example, if P2OS is in
direct-wheel
(VEL2) mode and is given
a command,
HEAD
disables that direct-wheel
velocity mode and starts
controlling the
Alternatively, disable the motors with the ENABLE command argument 0.
19
36
several
Table 7. P2OS movement commands
com-
Rotation
either
HEAD
DHEAD,
DCHEAD
P2OS
ROTATE
SETRA
SETRV
motion
P2OS
Translation
wheel-
VEL
MOVE
velocity
SETA
it
SETV
heading
19
Absolute heading
Differential heading from control point
Rotational speed
Rotational (de)acceleration to achieve setpoint
Sets maximum rotational velocity and is
velocity used for Colbert turn and turnto
command speeds.
Forward/back velocity
Forward/back distance
Translation (de)acceleration to achieve setpoint
Sets maximum translational velocity and is
used for Colbert move command speed.