Pioneer 3TM, 2TM manual Motion Commands, Rotation

ActivMedia Robotics Operating System

With AROS versions 1.3 and later, many of the controller’s operating parameters return to their FLASH-based default values upon disconnection with the client.18 For example, if the FLASH default for the maximum velocity is 1000 millimeters per second, and your client uses the SETV command #6 to reset the maximum velocity to 500 millimeters per second, the maximum velocity automatically will revert back to 1000 after your client disconnects and then reconnects for a subsequent session.

MOTION COMMANDS

The AROS motor-control servers accept several different client-motion commands of two mutually exclusive types: either independent-wheel or platform translational/rotational movements. The AROS servers automatically abandon any translational or rotational setpoints and switch to independent wheel-velocity controls when your client issues the independent-wheel VEL2 command #32, and vice versa.

Note that once connected, ActivMedia robots’ motors are disabled, regardless of their state when last connected. Accordingly, you must either enable the motors manually (white MOTORS button on the User Control Panel) or send the motors ENABLE client command #4 with the argument value of one.19 Monitor the status of the motors with bit 0 of the Flags integer in the standard SIP.

When in independent-wheel velocity mode (VEL2), the robot’s motion-control servers do their best to maintain precise wheel velocities. In practice, wheel slippage and uneven terrain will cause the robot to change heading, which your client must detect and compensate. When in translational/rotational (TR) motion control mode (recommended), your robot’s servers work to maintain both platform speed and heading.

Table 6. AROS motion commands

Rotation

HEAD (#12)	Turn to absolute heading at SETRV max velocity
DHEAD (#13),	Turn to heading relative to control point at SETRV max velocity
DCHEAD (#22)
ROTATE (#9)	Rotate at SETRV velocity
Translation
VEL (#11)	Translate forward/reverse at prescribed velocity (SETV maximum)
MOVE (#8)	Translate distance at SETV max velocity
Independent	Wheel

VEL2 (#32)

Set velocity for each side of robot (SETV maximum)

18With earlier versions, the changes persisted between sessions, and reverted to the FLASH defaults only after the controller was reset.

19Alternatively, disable the motors with the ENABLE command argument of zero.

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