Short Axis

This command can be used to control the Z-, Rx-, Ry-, and Rz-positions (also called the short axis) of the XBot.

Fieldbus Interface

PMC_ShortAxisMotion

Inputs

Name	Data Type	Description
Execute	BOOL	Execution of the function block begins on a rising edge of this input.
cmdLB	UINT	Any 2 byte Command Label, user defined.
XbotID	USINT	ID of the XBot. Real XBot IDs [1,78]. Virtual XBot IDs [100,127]. Macro IDs [128,191]
Mode	USINT	0: Absolute Positioning; 1: Relative Positioning
Type_	USINT	0: XBot center is used as center of rotation; 1: User defined center is used as center of rotation
PosZ	REAL	Target Z Coordinates (m)
PosRx	REAL	Target RX Coordinates (rad): Tilt around X-axis (rad)
PosRy	REAL	Target RY Coordinates (rad): Tilt around Y-axis (rad)
PosRz	REAL	Target RZ Coordinates (rad): Rotation around Z-axis (rad)
VelZ	REAL	Z Direction Travel Speed
VelRx	REAL	RX Direction Rotation Speed
VelRy	REAL	RY Direction Rotation Speed
VelRz	REAL	RZ Direction Rotation Speed
Cx	REAL	When Type = 1, this is used to specified the X location of the rotation center, in m. Otherwise, this is ignored
Cy	REAL	When Type = 1, this is used to specified the Y location of the rotation center, in m. Otherwise, this is ignored
PM_Controller	PMControllerType	Data structure that specifies which PMC to connect to. There should be only 1 instance of this variable for each connected PMC.

Outputs

Name	Data Type	Description
Ack	BOOL	Command has been accepted by the PMC when Ack = TRUE.
Done	BOOL	Execution successful. Function block is finished. (Note: Done will not become TRUE if Execute is already FALSE)
Busy	BOOL	Function block is active and must continue to be called.
Aborted	BOOL	Command aborted by another command.
Error	BOOL	If there is an error in processing the command, then Error = TRUE, otherwise, FALSE.
ErrorID	UINT	0x0: All OK. Otherwise, please see PMC Reply Codes.
TravelTime	REAL	Traveling time (s)

Ethernet Interface

MotionRtn ShortAxesMotionSI(ushort cmdLabel, int xbotID, POSITIONMODE positionMode, SHORTAXESCENTERMODE centerMode, double centerX, double centerY, double targetZmeters, double targetRXrads, double targetRYrads, double targetRZrads, double speedZmetersPs, double speedRXradsPs, double speedRYradsPs, double speedRZradsPs)

Parameters

Name	Type	Description
cmdLabel	ushort	Any 2 byte Command Label, user defined.
xbotID	int	ID of the XBot. Real XBot IDs [1,78]. Virtual XBot IDs [100,127]. Macro IDs [128,191]
positionMode	enum	ABSOLUTE (0) = absolute positioning, RELATIVE(1) = relative positioning
centerMode	enum	XBOT_CENTER (0) = XBot center is the rotation center; USER_DEFINED_CENTER_XY (1) = user defines the rotation center
centerX	double	If USER_DEFINED_CENTER_XY is used, then this is the x coordinate of the user defined center (meters)
centerY	double	If USER_DEFINED_CENTER_XY is used, then this is the y coordinate of the user defined center (meters)
targetZmeters	double	Target Z position (meters)
targetRXrads	double	Target RX position (rads)
targetRYrads	double	Target RY position (rads)
targetRZrads	double	Target RZ position (rads)
speedZmetersPs	double	Max speed in the Z axis (m/s)
speedRXradsPs	double	Max speed in the RX axis (rad/s)
speedRYradsPs	double	Max speed in the RY axis (rad/s)
speedRZradsPs	double	Max speed in the RZ axis (rad/s)

Returns

Name	Type	Description
MotionRtn.PmcRtn	PMCRTN enum	ALLOK (0): Command Accepted. Otherwise, please see Ethernet Reply Codes.
MotionRtn.TravelTimeSecs	float	Time required to complete this command, in seconds

Conditions

Operating Conditions
Preconditions	XBot is in the Idle state, Obstacle Detected state, Motion state, Stopped state, Hold Position state, or Waiting state.
Postconditions	If the XBot is ready to immediately begin executing the command, then the XBot will enter the Motion state. Otherwise, the XBot state remains unchanged, but the command will be added to the XBot's motion buffer.

Description

This command can be used to control the Z-, Rx-, Ry-, and Rz-positions (also called the short axis) of the XBot.

The maximum speed for each axis must be specified. The ending speed is zero. The input maximum speed will be automatically constrained if they are below or above the system limits. (The upper system short axes speed limit can be defined in the Configurator.)

The lower limit is Vz = 0.0002 m/s, Vrx = Vry = Vrz = 0.02 rad/s

It’s possible to rotate the XBot around some point that is not its own center. Use the “User Specified Center” mode.

In this case, the rotation center is specified in absolute coordinates with respect to the system origin. The XBot will move in X,Y, and RZ to always maintain the same distance from the rotation center, and achieve the desired RZ value.

It is also possible to specify the tilt relative to the user defined rotation center.

In the user defined section mode, Z is used to specify the rotation center height, and Rx and RY is used to specify the tilt relative to the rotation center.

The Rx and Ry (tilt) limits depend on the levitation height of the XBot. When the XBot is at a greater height, the XBot can achieve a greater tilt angle without touching the flyway. Conversely, if the XBot height is low, commands with tilt angles that would cause the XBot to touch the flyway will be rejected.