Planet XBots Control

A planet motion command is a special type of connected Group, where a particular XBot is the Star or Sun XBot, and the other XBots (planets) move related to the Sun XBot. The planet XBot’s coordinate system’s origin is the Sun XBot’s current position.

Fieldbus Interface

PMC_PlanetMotionCtrl

Name	Data Type	Description

Name	Data Type	Description
Execute	BOOL
Level	USINT	0: Disconnect from Star XBot; 1: Connect to Star XBot
StarXID	USINT	ID of the Star XBot
nXbots	USINT	Number of XBots to add as planets, from 1 to 32
PlanetXID	USINT[0..31]	Array of size 32, enter up to 32 planet XBot IDs
PM_Controller	PMControllerType

Name	Data Type	Description

Name	Data Type	Description
Done	BOOL
Busy	BOOL
Aborted	BOOL
Error	BOOL
ErrorID	UINT

Ethernet Interface

PMCRTN EditPlanetXbots(int sunXbotID, int planetXbotCount, int[] planetXbotIDs, PLANETOPTIONS action)

Name	Type	Description

Name	Type	Description
sunXbotID	int	ID of the Sun or Star XBot
planetXbotCount	int	Number of planet XBots involved in this command
planetXbotIDs	int[]	IDs of the Planet XBots
action	enum	REMOVEPLANETS: remove planet XBots, ADDPLANETS: add planet XBots

Name	Type	Description

Name

Type

Description

PMCRTN

PMCRTN enum

Conditions

Operating Conditions

Operating Conditions

Preconditions

Postconditions

The specified planet XBot(s) will start following the specified Sun XBot

Description

A planet motion command is a special type of connected Group, where a particular XBot is the Star or Sun XBot, and the other XBots (planets) move relative to the Sun XBot. The planet XBot’s coordinate system’s origin is the Sun XBot’s current position. An example of a system with 2 M3-06 XBots (120mm x 120mm) is provided below

Moving the Planet XBot will change the relative position between the Planet and Sun XBot.

Note: The feedback position of the Planet XBot does NOT use the Sun XBot’s position as the origin. It uses the system origin like any other XBot.

Moving the Sun XBot will cause the Planet XBot to follow the Sun.

It is possible to move both Planet XBot and Sun XBot simultaneously.

In this example, the Planet XBot is in a circular motion around the Sun XBot while the Sun XBot is moving in a straight line. The result is the Planet XBot will follow a spiral path so that it is revolving in a perfect circle around the Sun XBot even during Sun XBot motion.

It is possible for all real XBots to be planet XBots, and revolve around a virtual Sun XBot of size 0,0.

Virtual XBot ID starts from 100, and end at 127. It can be moved just like a normal XBot.

Performance Limits for Sun-Planet Movers

There are kinematic limitations placed on both the Sun XBot and the Planet XBots so that the combined motion does not exceed the system limits.

	Sun XBot	Planet XBot

Sun XBot

Planet XBot

Speed

0.5 x System Speed Limit

Acceleration

factor (fs) x Acceleration Limit (As)

fs = min(fp)
As (for Virtual XBot) = min(Ap)
As (for Real XBot) = based on System Acceleration Limit and assigned stereotype

factor (fp) x Acceleration Limit (Ap)

fp = Ap / (As + Ap)
Ap = based on System Acceleration Limit and assigned stereotype (therefore this value can be different for each Planet XBot)

Jerk

0.5 x System Jerk Limit

Note that the System Jerk Limit can be changed using Set Jerk Limit.

Behaviour During Obstacles

Unlike standard XBots during motion commands, if any of the Sun or Planet XBots encounter an obstacle (i.e. another XBot is in the way), they will all enter the Stopped State simultaneously and their motions will not be resumed even if the obstacle XBot is moved away. The motion commands need to be sent again.

Planar Motor Technical Portal

Planet XBots Control

Fieldbus Interface

Ethernet Interface

Conditions

Description

Feedback and Comments