robot keeps getting stuck on medium-pile rugs, it acts like it's hitting a wall.

Diagnosis

The Roborock S8 MaxV Ultra uses a combination of LiDAR, an RGB camera, and infrared cliff sensors to navigate. When the robot treats a medium-pile rug like a solid wall, it is usually experiencing a "phantom obstacle" trigger. This happens because the infrared light emitted by the cliff sensors (located on the bottom perimeter of the chassis) is being absorbed or refracted by the specific color and texture of the rug fibers. Instead of the light bouncing back to the sensor to confirm a flat surface, the sensor perceives a "void" or a sudden drop, triggering a safety stop to prevent the robot from falling down stairs. Additionally, medium-pile rugs can create physical resistance against the front bumper's tactile sensors. If the rug is thick enough to slightly depress the bumper mechanism without moving the robot forward, the onboard logic interprets this as a collision with a hard object. You can confirm this by observing the robot's behavior: if it stops abruptly and rotates 45 degrees to "find a way around" the rug without actually touching a wall, it is a sensor-based false positive. If it pushes into the rug and then reverses, it is a physical bumper trigger.

How to Fix It

To resolve this, you must optimize the software's interaction with the floor surface and ensure the sensors are operating at peak efficiency. Follow these exact steps:

1. Open the Roborock App and navigate to the "Map Management" section.
2. Select "Edit Map" and locate the specific area where the medium-pile rug is positioned.
3. Set a "No-Mop Zone" or a "No-Go Zone" specifically for the rug if you only want it vacuumed, or better yet, use the "Carpet Settings" menu to set the robot to "Carpet Boost" mode. This increases the RPM of the dual rollers, which helps the robot "glide" over the fibers rather than pushing into them.
4. Go to Settings > Robot Settings > Carpet Cleaning and ensure "Mop Lifting" is set to the maximum height. If the mop pads are dragging even slightly on a medium-pile rug, the friction creates a drag force that triggers the collision sensor.
5. Perform a deep clean of the cliff sensors. Turn the robot upside down and use a dry, lint-free microfiber cloth to wipe the six infrared windows located along the bottom edge. Use a cotton swab with a tiny drop of isopropyl alcohol (70%) if there is a film of grime that a dry cloth cannot remove.
6. Calibrate the LiDAR sensor by ensuring there are no objects within 10cm of the top turret, then restart the robot to refresh the spatial map.

If That Didn't Work

• The "White Tape" Method: If the rug is dark-colored or black, the cliff sensors will almost always fail. Apply small pieces of matte white electrical tape or specialized "cliff sensor covers" over the infrared windows on the bottom of the robot. This tricks the sensor into thinking it is always on a white surface, preventing the "phantom cliff" trigger. Warning: Only do this if your home has no stairs.
• Physical Bumper Reset: Check the front bumper for trapped debris. Use a can of compressed air to blow out the gaps around the bumper perimeter. If a small pebble or piece of grit is lodged in the bumper spring, the robot will be hypersensitive to the slight resistance of a rug.
• Rug Underlayment: If the rug slides even a fraction of an inch when the robot hits it, the robot perceives this as an unstable surface and stops. Place a non-slip rubber rug pad beneath the medium-pile rug to anchor it firmly to the floor.
• Firmware Rollback/Update: Check for a firmware update in the app. Roborock frequently releases "carpet detection" patches that adjust the sensitivity thresholds of the infrared sensors to reduce false positives on specific fabric blends.

Heads Up

• Stair Danger: Never operate the robot with taped-over cliff sensors if you have a multi-level home; the robot will drive straight down your stairs.
• Mop Saturation: Ensure your mop pads are properly seated in the MaxV Ultra dock. If they are misaligned, they can drag on the rug, increasing the physical resistance that triggers the "hitting a wall" behavior.
• Dark Rugs: Be aware that deep navy, charcoal, or black rugs are notorious for absorbing infrared light, which is the primary cause of this specific malfunction.
• Sensor Maintenance: Clean the bottom sensors weekly. Dust buildup on the infrared windows is the leading cause of navigation errors in high-pile environments.