Is overshoot the same as the robot missing its taught point?

No. Overshoot is transient: the arm passes the point then settles back onto it. If it settles in the wrong place and stays there, that points to a repeatability or mastering issue. Overshoot describes the transient on the way to settling.

Why does the same program overshoot with a new tool but not the old one?

Load inertia changed. A heavier or longer tool carries more momentum into the stop, so the axis passes the target further before the loop brings it back. Getting the payload and center of gravity set correctly gives the servo tuning an accurate picture of what it's decelerating.

Will slowing the move down reduce overshoot?

Often, because a gentler deceleration means less momentum to absorb at the target. But the underlying balance is servo gain against load inertia, so speed is one lever among several rather than a guaranteed fix.

Motion

Overshoot

Overshoot is how far the robot's actual position travels past the commanded target before it settles back to that target.

What it is

Overshoot is the amount an axis or the TCP passes beyond a commanded position before it comes to rest on that position. You command a stop at a point, the arm gets there carrying momentum, and it briefly goes past before the servo pulls it back.

It shows up at the end of a move, at the point where motion decelerates to a stop or reverses. The bigger the mass in motion and the harder the deceleration, the more the axis wants to keep going past the target.

How it actually works

A servo axis is a mass being positioned by a controlled motor. As the arm decelerates into the target point, stored kinetic energy in the payload and the link inertia has to be absorbed. If the deceleration is aggressive or the load is heavy, the axis crosses the setpoint before the loop reverses torque to bring it back, so the position curve rings past the target and settles in.

How much it overshoots depends on the balance between the servo gain, the deceleration profile, and the load inertia. High gain reacts hard and can ring past then settle; too little gain and the axis is sluggish. A heavier payload or a longer, more extended arm pose raises the effective inertia, which is why the same program can settle clean with a light tool and overshoot noticeably with a heavy one. Because overshoot depends on the payload and pose, no single number applies: the honest figure is whatever your accel settings and load produce at that point.

How it differs

Following error · Following error is the gap between where the axis is commanded to be and where it actually is while the move is running; overshoot is a specific end-of-move behavior where the actual position passes the final target after the command has stopped. Following error trails behind the command; overshoot runs ahead of the target it was supposed to stop on.
Path deviation · Path deviation is how far the TCP strays from the intended path in the middle of a move, cornering or blending. Overshoot is about the endpoint: passing the stop position before settling, not wandering off the line during travel.

Where you meet it in the field

FANUC M-20iD/25 · On a production arm like this, overshoot tends to become visible after fast moves into a stop, where deceleration and payload inertia combine at the target point.
Spot welding · Approach-to-stop moves have to settle at the weld spot without the gun passing through the part, so overshoot at the stop point is something you tune out before it costs you.

Common questions

Is overshoot the same as the robot missing its taught point?: No. Overshoot is transient: the arm passes the point then settles back onto it. If it settles in the wrong place and stays there, that points to a repeatability or mastering issue. Overshoot describes the transient on the way to settling.
Why does the same program overshoot with a new tool but not the old one?: Load inertia changed. A heavier or longer tool carries more momentum into the stop, so the axis passes the target further before the loop brings it back. Getting the payload and center of gravity set correctly gives the servo tuning an accurate picture of what it's decelerating.
Will slowing the move down reduce overshoot?: Often, because a gentler deceleration means less momentum to absorb at the target. But the underlying balance is servo gain against load inertia, so speed is one lever among several rather than a guaranteed fix.