How Do You Increase UR10 Speed Without Protective Stops?

The UR10 completes the same pick-and-place cycle, then intermittently enters a C153A4 protective stop after speed or acceleration is raised. Follow the motion command from the programmed waypoint through trajectory generation, joint motion, payload compensation, the tool, and the mounting base. A high TCP speed command is only one part of that path; acceleration, joint geometry, payload data, center of gravity, blending, and structural stiffness usually decide whether the cycle remains repeatable.

Where does the motion request stop?

PolyScope or URScript supplies a target pose, velocity, acceleration, and blend. The controller converts that Cartesian request into coordinated joint motion. Each joint must follow its calculated position while compensating for the robot links, tool, and payload. A protective stop can occur when actual motion departs too far from commanded motion, even when every waypoint is reachable and the stop appears between waypoints.

Path element	What can limit the move	Commissioning check
Waypoint command	Velocity, acceleration, orientation change, or insufficient blend	Record the values on every affected segment
Trajectory and inverse kinematics	One joint reaches its speed or dynamic limit before the TCP reaches the requested speed	Review joint motion, not only TCP motion
Payload compensation	Incorrect mass or center of gravity increases tracking error	Load the correct empty-tool and part-held data
Mechanical structure	A flexible base, loose tooling, or moving workpiece stores and releases momentum	Inspect the base, fasteners, tool, and vacuum grip
Safety configuration	Normal and reduced modes impose different operating constraints	Prove each mode and every transition independently

A requested 3000 mm/s does not prove that the path can reach or sustain that TCP speed. On a short move, acceleration and deceleration consume most of the distance. On another pose, a joint limit can cap TCP speed first.

Gate check: Reproduce the original cycle at its stable settings and identify the first segment whose warning level or behavior changes when only one motion value is increased.

Is the physical installation rigid enough?

Layer one first. A UR10 carries substantial momentum during a long, fast move, especially with the arm extended. A compliant pedestal deflects during acceleration and springs back during deceleration. That motion changes the relationship between the controller's expected joint trajectory and the measured motion, while also increasing settling time at the destination.

Check the pedestal, anchor points, adapter plate, robot mounting bolts, gripper attachment, vacuum cup, hose routing, and part retention. Look for visible pedestal motion, fastener movement, tool vibration, hose tension, or a part shifting in the cup. Test the most demanding combination of reach, payload, rotation, and deceleration rather than a convenient pose near the base.

High-duty installations have operated near 90% of the maximum enterable speed and acceleration for long schedules—including 24 hours per day for 6 days per week—while carrying no more than 20% of rated payload. That operating record demonstrates feasibility on those machines, not a transferable UR10 limit. The rigid base and low payload were material conditions.

Gate check: Run the problem move slowly while observing the base and tool, then repeat with acceleration raised modestly. Do not tune around any detected mechanical movement.

Are TCP, payload, and center of gravity correct?

The controller's dynamic model depends on the active TCP, payload mass, and center of gravity. Update payload data when the robot acquires or releases a part. A program that retains the empty-gripper data while carrying a part asks the controller to compensate for the wrong inertia and gravitational torque.

Cycle state	Payload mass	Center of gravity	Required action
Approaching the part	Gripper only	Gripper assembly CoG	Activate the empty-tool values
After vacuum pickup	Gripper plus part	Combined gripper-and-part CoG	Call set_payload(m,GoG) using the verified values
After placement	Gripper only	Gripper assembly CoG	Restore the empty-tool values

The documented commissioning example involved a 4 kg part and a 4 kg gripper, so the moving payload was 8 kg. Its motion used the default 2.5 m/s2 acceleration and included wrist-orientation changes. That case is separate from the lighter 1 lb to 3 lb conveyor parts; copy neither its mass nor its CoG.

Measure or calculate the combined CoG in the tool coordinate system. Confirm the active TCP represents the vacuum pickup point. A correct total mass with an incorrect CoG can still produce large model errors when the wrist rotates or the arm extends.

Gate check: Display or log the active payload state at pickup and release, then run the affected path at the prior stable speed with both payload transitions active.

Should speed or acceleration change first?

Acceleration is usually the more critical setting. Raising speed alone may make no cycle-time difference when the segment is too short to reach it. Raising acceleration increases torque demand and tracking stress immediately, including on short moves. Excessive acceleration can therefore create protective stops before the programmed top speed is reached.

Change	Likely effect	Diagnostic meaning
Raise speed, hold acceleration	No change if the move never reaches the new speed	The segment is acceleration- or distance-limited
Raise acceleration, hold speed	Faster ramp with higher dynamic load	A new warning points toward torque, tracking, payload, or stiffness limits
Reduce acceleration around wrist rotation	Lower inertial demand during orientation change	Improvement identifies the dynamic segment
Change speed and acceleration together	Cause becomes ambiguous	Not suitable for fault isolation

Do not interpret a software entry limit as a guaranteed TCP capability. For comparison, the stated 1 m/s UR5 value was described as a conservative average maximum. Some downward joint motions can exceed it when shoulder and elbow move in the same direction with a 350 mm TCP, while a linear move close to the base may fail to reach it because the base joint reaches maximum joint speed. That explanation illustrates the kinematic dependency; it does not define a UR10 speed rating.

Gate check: Increase only speed first. If measured cycle time stops improving, restore it and tune acceleration in small steps while watching the same path segment.

Can a midpoint and blend control deceleration?

A long move with a large base rotation can carry enough momentum that the final waypoint demands an abrupt stop. One recorded UR10 application rotated the base through 180 degrees with the arm about three-quarters extended and could not stop smoothly at the desired speed. Reducing the common acceleration also reduced acceleration at the start, costing cycle time.

Insert a blended midpoint between the start and finish. Give the midpoint and destination the same velocity, but assign their own acceleration values. In this motion pattern, the first value shapes acceleration into the move and the second shapes deceleration toward the destination. Use the largest blend that remains compatible with clearance, process geometry, and the intended path.

1. Jog or calculate a midpoint on the desired path between the start and destination.
2. Add the midpoint as a waypoint.
3. Apply a blend so the robot does not stop at the midpoint.
4. Set the midpoint and destination to the same velocity.
5. Use a lower acceleration value on the destination segment when momentum makes the final stop harsh.
6. Run slowly and verify that the blended path does not cut into fixtures, the conveyor, or the protected area.

For calculated waypoints, is_within_safety_limits() can screen a target before commanding it. Passing that check establishes that the position is acceptable to the safety-limit test; it does not prove that a high-speed blended trajectory will remain dynamically stable.

Gate check: Trace the entire blended path at reduced speed, then confirm that the final deceleration becomes smoother without introducing an intermediate stop.

How do you isolate a C153A4 protective stop?

An intermittent C153A4 during otherwise identical cycles points to operation near a dynamic boundary. Small differences in part position, vacuum grip, starting joint state, temperature, or settling can decide which side of that boundary a cycle reaches. Diagnose the margin instead of waiting for the protective stop popup.

Place position_deviation_warning() in BeforeStartSequence so it remains active during the program run. It reports position-deviation proximity on a scale from 0 to 1, where 1 is close to a protective stop. A commissioning practice using a warning threshold of 0.8 provided useful operating margin: motion was adjusted until the cycle completed without those warnings.

1. Enable position_deviation_warning() before the program starts.
2. Run enough complete cycles to include pickup, loaded travel, wrist rotation, placement, and return.
3. Correlate every warning with the active waypoint, joint configuration, payload state, and acceleration.
4. Reduce acceleration on the first repeatable warning segment.
5. If the warning remains, inspect its blend, extension, joint rotation, payload data, and structural movement.
6. Repeat until the full cycle runs without the selected warning.
7. Remove the diagnostic call after tuning because it writes to the log and can flood it.

The warning value cannot be assigned to a program variable in the described implementation. It therefore cannot directly drive the speed slider in a background control loop. Treat it as a commissioning diagnostic, not an automatic anti-stop controller.

Gate check: Complete the chosen endurance run with no 0.8 warnings and no C153A4 stops before increasing another setting.

How do you commission normal and reduced operation?

An area sensor can request a lower operating mode when a person is present, but the sensor, safety input, safety configuration, stopping behavior, and reset policy must form one validated safety function. Faster unattended motion also changes stopping distance, stored energy, reach during stopping, and the consequences of an unexpected release from the vacuum cup.

Mode	Commissioning purpose	Proof required
Reduced operation	Operation under the application's configured collaborative constraints	Challenge every sensor zone and confirm the robot enters the intended mode
Normal high-speed operation	Cycle-time production when the protected area is clear	Confirm payload, trajectory, warning margin, and stopping behavior at the final settings
Mode transition	Response when the area state changes during motion	Trigger the sensor at the worst point in the fastest, heaviest move

1. Validate the sensor coverage and its connection to the configured safety function.
2. Prove reduced operation before enabling faster normal operation.
3. Start normal-mode testing from the stable production settings.
4. Raise one speed or acceleration setting at a time and record cycle time plus warning location.
5. Stop increasing a value when cycle time no longer improves, warnings appear, or motion becomes mechanically harsh.
6. Test the worst-case payload, reach, wrist orientation, base rotation, and blend combination.
7. Run the required unattended-duration trial, then inspect the log, mounting structure, tool, and part retention.

Gate check: From the fastest loaded segment, activate every area-sensor zone and confirm the commanded mode transition and stopping response match the validated safety configuration.

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