Move.Approach Method

Moves the robot in a position-controlled motion to the clearance position for a specified Location.

Move.Approach (location_1, profile_1)

Prerequisites

High power to the robot must be enabled.
The robot must be homed.
The robot must be Attached by the thread.

Parameters

location_1

A required Location Object or an expression that evaluates to a Location Object value. Can be either a Cartesian or an Angles type value.

profile_1

A required Profile Object or an expression that evaluates to a Profile Object value. Can specify either Cartesian straight-line or joint interpolated motions.

Remarks

This method simultaneously moves all of the axes of the robot in a coordinated, position-controlled motion to a clearance position for a specified Location. In many cases, as the robot moves towards a part position or is being retracted from a part position, it must first move through an intermediate clearance position. For example, when picking up a part, it is often necessary to position the robot’s gripper directly over the part before moving down to pick it up. Likewise, after gripping a part, it is often necessary to retract the robot’s end effector and the part in order to clear other parts or to avoid scrapping the part along it’s supporting surface. Since this is such a common operation, all Location Objects contain information on their required clearance position. The Approach method automatically makes use of this clearance data to compute an intermediate “approach position” that is taken as the destination for the Approach method’s motion.

Specifically, each Location contains a ZClearance distance and a ZWorld Boolean flag. The ZClearance property specifies the Z-axis offset distance for the approach position in millimeters. If the ZWorld property is True, the clearance position is interpreted as being directly above (or below) the “total position” of the Location in the world coordinate system at the Z value specified by ZClearance. For example, if the “total position” of a Location is at an X, Y, Z value of (10,20,30) and ZClearance is 52.3 and ZWorld is True, the approach position would be (10,20,52.3). A world Z clearance position is often used if the robot is loading or unloading a box and the robot must clear the edge of the box independent of how far into the box it must reach.

If the ZWorld property of a Location is False, the clearance position is a relative distance along the negative Z-axis of the robot’s tool. This clearance distance corresponds to having the robot retract an incremental distance along the major axis of its tool or gripper. For example, if the “total position” of a Location is at an X, Y, Z value of (10,20,30) and ZClearance is 52.3 and ZWorld is False and the robot’s tool is pointed along the positive world X-axis, the approach position would be (-42.3,20,30).

A tool Z clearance position is typically utilized if the robot is tending a number of machines and you always wish to retract the gripper a fixed distance from each machine before moving to the next Location. By making use of GPL’s robot kinematics option, approach specifications can be automatically applied to both Cartesian and Angles Location Objects. Once the Approach method computes the desired motion destination, the motion execution is identical to the Move.Loc method. The motion can be a Straight-line or joint interpolated motion, can be blended with the previous and the next motions as desired, and the performance parameters are defined by profile_1 (e.g. Speed, Accel, Decel, AccelRamp, DecelRamp, InRange).

Examples

Dim prof1 As New Profile' Create new profile initialized to default values
Dim loc1 As New Location    ' Create new location value
loc1.XYZ(10,20,30,0,180,20)    ' Define position to move to
loc1.ZClearance = 10           ' Require 10 mm clearance in Tool
Move.Approach(loc1,prof1)      ' Move to clearance position
Move.Loc(loc1, prof1)          ' Move to loc1 using prof1