vcServoController

vcServoController is a controller for driving independent joints. The controller itself only supports forward kinematics and cannot be used in robots rather with them. For example, a servo controller can be used for external axis systems, grippers, fixtures, weld guns, and other simple mechanical structures.

See in: Overview

Module: vcRobotics

Parent: vcBehavior

Children: vcRobotController

Referenced by: vcDof.Controller, vcJoint.Controller, vcJoint.ExternalController, vcSimJointExportField.Controller

Properties

Learn how to use properties here. The properties are also inherited from the parent class.

Name	Type	Access	Description
FlangeNode	vcNode	RW	Defines the flange node of servo, for example the mount plate or carriage for other kinematic structures.
HeartbeatTime	Real	RW	If UseHeartbeat is set to True, defines the interval or pulse for updating joints.
JointCount	Integer	R	Gets the number of joints in servo.
Joints	vcList[vcJoint]	R	Gets a list of all joints referenced by servo.
RootNode	vcNode	RW	Defines the root node of servo, thereby the fixed base of kinematic structure.
Speed	Real	RW	Defines joint speed as a percentage of maximum speed for driving joints in range 0 to 100.
UseHeartbeat	Boolean	RW	Turns on/off the use of a heartbeat or pulse to drive and update joints.

Methods

Learn how to use methods here. The methods are also inherited from the parent class.

Name	Return Type	Parameters	Description
calcMotionTime	Real	None	Returns the calculated motion time of servo using current joint values and listed targets. Returns: Real: motion time.
findJoint	vcJoint	String joint_name	Returns the first joint matching a given name in servo; otherwise returns None. See more Parameters: joint_name (String): joint name Returns: vcJoint: joint found or None
getJoint	vcJoint	Integer joint_index	Returns the first joint matching a given name in servo; otherwise returns None. See more Parameters: joint_name (String): joint name Returns: vcJoint: joint found or None
getJointTarget	Real	Integer joint_index	Returns the target value of a joint at a given index in servo. See more Parameters: joint_index (Integer): index Returns: Real: target value of a joint
getJointValue	Real	Integer joint_index	Returns the current value of a joint at a given index in servo. See more Parameters: joint_index (Integer): index Returns: Real: current value of a joint
move	vcTask	list jvalues	Drives all joints in servo to target values, and then returns the actual motion time. See more Target values for each joint in servo can be given as separate, optional arguments. Parameters: ([Real joint_0, ... Real joint_n]): joint values (): No arguments Returns: Real: actual motion time
move	vcTask	None	-
moveImmediate	None	List[Real] values	Drives all joints in servo to target values in zero simulation time. See more Target values for each joint in servo can be given as separate, optional arguments. Parameters: [Real joint_0, ... Real joint_n]: joint values
moveJoint	vcTask	Integer index, Real value	Moves a joint at a given index in servo to a given value, and then returns the actual motion time. See more Parameters: joint_index (Integer): index joint_value (Real): joint value Returns: Real: actual motion time
setJointTarget	None	Integer joint_index, Real joint_value	Sets the target value of a joint at a given index in servo to a given value. Parameters: joint_index (Integer): index joint_value (Real): joint value
setMotionTime	None	Real time	Forces the servo to execute joint movements at a given motion time. Parameters: time (Real): motion time

Events

Learn how to use events here. The events are also inherited from the parent class.

Name	Parameters	Description
OnHeartbeat	None	Triggered when a pulse or heartbeat is generated by servo. See more Note: This event handler can be used by a vcRobotController object executing a vcProcessStatement object in robot program. Parameters: servo (vcServoController) event_type (vcController)

Example: Drive Servo One Axis

""" This example shows how to set a target position for a servo joint and drive the servo to the target value."""

import vcCore as vc

async def OnRun():
  comp = vc.getComponent()
  servo_x = comp.findBehavior("ServoX")
  joint_index = 0
  x_target = 100
  servo_x.setJointTarget(joint_index,x_target)  
  await servo_x.move()

Example: Drive Multiple Servos Asynchronously

""" This example shows how to control servos asynchronously by using the vcServoController behavior.  """

import vcCore as vc

async def OnRun():
  comp = vc.getComponent()
  servo_x = comp.findBehavior("ServoX")
  servo_y = comp.findBehavior("ServoY")
  servo_z = comp.findBehavior("ServoZ")
  joint_index = 0
  x_target = 100
  y_target = 100
  z_target = 100
  servo_x.setJointTarget(joint_index,x_target)
  servo_y.setJointTarget(joint_index,y_target)
  servo_z.setJointTarget(joint_index,z_target)

  # start asynchronous motions 
  x_motion = servo_x.move() # returns an awaitable task
  y_motion = servo_y.move()
  z_motion = servo_z.move()

  # wait until all motions are completed
  await vc.allTasks([x_motion,y_motion,z_motion]) # waits for all tasks to complete
  print("All servos have reached their target positions.")