Robot Motion Commands

SPEL⁺ includes several commands for controlling the robot from your programs.

6.18.1 Homing the robot

The Home command moves the robot to a user defined "park" or "idle" position. This command works for all robots. It is mainly used for absolute encoder robots that normally do not need to be mechanically homed. Use the HomeSet command to set the home position and the Hordr command to set the home order.

6.18.2 Point to point motion

Point to point (PTP) commands move the robot from its current position to a specified point. Motion may not be in a straight line.

To set the speed for point to point commands, use the Speed command. To set acceleration and deceleration, use the Accel command.

Command Description

Go Move directly to a point using point to point motion.

Jump Jump to a point. First move up to the current LimZ setting, the move over the destination point, then move to the point. The Arch table settings determine the Jump profile.

Jump3 Jump to a point in 3 dimensions.

Pass Move near one or more points.

TGo Move directly to a point in a tool coordinate system.

6.18.3 Linear motion

Linear motion commands move the robot from its current position to a specified point in a straight line. Liner motion is a CP (Continuous Path) motion.

To set velocity (speed) for straight motion, use the SpeedS command. To set acceleration and deceleration, use the AccelS command.

Command Description

Move Move in a straight line to the specified point.

TMove Move in a straight line to the specified point in a tool coordinate system.

Jump3CP Jump to a point in 3 dimensions using CP motion.

6.18.4 Curves

Curves commands move the robot in a circular arc. Curves is a CP (Continuous Path) motion.

To set velocity (speed) for Curves, use the SpeedS command. To set acceleration and deceleration, use the AccelS command.

Command Description

Arc Move the robot through one point to another point using circular interpolation.

6. The SPEL+ Language

6.18.5 Joint motion

Command Description

JTran The JTran command can be used to move one joint of the robot to a position specified in degrees or millimeters, depending on the joint type. The speed and acceleration are the same as for point to point motion commands -- i.e., specified with Speed or Accel commands.

PTran The PTran command can be used to move one joint of the robot to an encoder pulse position. The speed and acceleration are the same as for point to point motion commands -- i.e., specified with Speed or Accel commands.

Pulse The Pulse command can be used to move all joints of the robot to encoder pulse positions. The speed and acceleration are the same as for point to point motion commands -- i.e., specified with Speed or Accel commands.

PG_Scan The PG_Scan command can be used to rotate a pulse generator axis of a Joint-type single axis PG robot continuously in CW/CCW directions. (To rotate it continuously, you need to enable the continuous rotation parameter.) The speed and acceleration are the same as for point to point motion commands -- i.e., specified with Speed or Accel commands.

6.18.6 Controlling position accuracy

Use the Fine command to adjust position accuracy for the end of a motion command. Fine specifies, for each joint, the allowable positioning error for detecting completion of any given move. The lower the Fine settings, the more accurate the final position of the joint, which can cause slower performance. Conversely, large Fine settings can speed up motion commands, but position accuracy will decrease. For many applications, the default settings can be used.

6. The SPEL+ Language

6.18.7 CP Motion Speed / Acceleration and Tool Orientation

When you attempt to change only the tool orientation while keeping the tool tip of the robot arm at the specified coordinate point or when the tool orientation variation is larger than the travel distance of the tool tip, moving the arm by normal CP motion commands will cause an increase in the variation of speed, acceleration and deceleration of tool orientation. In some cases, an error will occur.

To prevent these situations, add the ROT parameter to the CP motion commands. The arm will be moved based on the specified angular velocity and acceleration/deceleration of the main axis regarding the orientation variation.

The angular velocity and acceleration/deceleration of the main axis regarding the orientation variation should be specified with the SpeedR and AccelR commands in advance.

For example:

SpeedR 50 ' degree/sec

AccelR 200, 200 ' degree/sec² Move P1 ROT

The tool orientation variation is normally comprised of orientation variations of more than one rotation axis.

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The SpeedR and AccelR parameters specify the angular velocity and acceleration/

deceleration of the main axis regarding the orientation variation. Therefore, actual angular velocity and acceleration/deceleration of the orientation variation are different from the parameters except for the case where the rotation axis of the orientation is only one.

While the motion command with the ROT parameter is executed, the specified SpeedS and AccelS parameters are invalid.

The ROT parameter can be used with the following motion commands:

Move BMove Arc TMove Arc3 Jump3CP

6.18.8 PTP Speed / Acceleration for Small Distances

You can change the speed and acceleration for small distances using PTPBoost and PTPBoostOK. Normally, PTPBoost is not required. In certain cases, you may want to shorten the cycle time even if vibration becomes larger, or conversely you may want to reduce vibration even if cycle time becomes longer. PTPBoost is a robot parameter with values from 0 – 100 that affects the speed and acceleration for small distances. Normally, for small distance motion, the desired speed cannot be attained using the current acceleration. By increasing PTPBoost, acceralation, deceleration, and speed are increased for small distance motion. To check if a motion command will be affected by PTPBoost, use the PTPBoostOK function. See PTPBoost and PTPBoostOK in the SPEL+ Language Reference manual for more details.

6. The SPEL+ Language