Cleaning the collision sensor of the robot vacuum cleaner Xiaomi: why it glitches and how to fix

Why Xiaomi’s Robot Vacuum Began to Fight Against Furniture and How It Connects with Sensors

Your Xiaomi Mi Robot or Roborock suddenly stopped skirting obstacles neatly? Does it bump into chair legs, scratch furniture, or get stuck in corners? 80% of the time, the problem is contaminated impact sensors, the little perimeter sensors around the body that detect obstacles, and these sensors work like infrared or laser scanning, and even a thin layer of dust or fat can distort their signals.

The manufacturer says that the sensors do not require maintenance, but in practice it is different. In a real apartment — with animal hair, construction dust or kitchen fumes — the sensors become dirty in 3-6 months of active use, while the robots of the Mi Robot Vacuum-Mop 2 and Roborock series. S7 They're particularly sensitive to pollution because of the compact position of the sensors under the bumper, and if you ignore the cleaning, over time, the vacuum cleaner will go blind, either not seeing the obstacle or falsely going off in the empty space.

This article provides a step-by-step guide to safely clean the collision sensors on any Xiaomi robot vacuum cleaner (including the Roborock, Dreame, and Viomi models), what tools you need, how to disassemble the bumper without damage, and what to do if cleaning didn’t work, and the typical errors that cause the sensors to break.

Signs of contaminated sensors: when it's time to clean

Sometimes the gyroscope, the laser rangefinder (LiDAR), or even the bumper's mechanical damage are to blame, but there are 5 key symptoms that directly indicate sensor contamination:

• 🚫 The robot does not respond to obstacles from the front, hits and continues to move, as if he did not notice anything.
• 🔄 Often unfolds in place for no apparent reason, as if “seeing” a non-existent barrier.
• 🐢 Moves unusually slowly along walls or furniture, as if “probing” the path.
• 🔴 In annex Mi Home/Roborock Bumper Sticked or Collision Sensor Error.
• 🔄🔄 Begins to randomly rush around the room, losing orientation (especially in the dark).

If you have 2-3 items on your vacuum cleaner list, it's time to clean it, but first check if there's any fault with other equipment.

⚠️ Attention: If a robot starts beating on furniture after a fall or a big impact, cleaning the sensors is unlikely to help, most likely, the bumper itself or its mounts are damaged, in which case you need a diagnosis in the service center.

What tools will be needed to clean the sensors

There's no need for professional tools to clean the sensors safely -- enough to be found in every home -- but there's a nuance: some materials, like rough fabric or high-concentration alcohol, can damage the delicate lenses of the sensors.

• 🧴 Isopropyl alcohol (70-90%) is the best solvent for fat and dust. Don't use medical alcohol or vodka! They leave a divorce.
• 🧻 Microfiber wipe (for example, for glasses) – does not scratch plastic and does not leave villi.
• 🪲 Cotton swabs (preferably with a plastic rod, not a wooden one - it can crumble).
• 🔍 Lantern or magnifier – to see fine contaminants in the grooves of sensors.
• 🔧 Plastic blade or mediator - for careful tweaking of the bumper (metal screwdrivers scratch the body!).
• 💨 Compressed air balloon (optional) - for blowing dust from hard-to-reach places.

What NOT to use:

• 🚫 Water or soap solution - can get inside the housing and cause corrosion of contacts.
• 🚫 Abrasive materials (sandpaper, hard brushes) - scratch the sensor lenses.
• 🚫 Acetone, gasoline, solvents - destroy plastic and rubber seals.
• 🚫 Dust cleaner – static electricity can damage electronics.

If you have a model with a laser sensor (LiDAR) (for example, Roborock) S6 MaxV or Xiaomi Mi Robot Vacuum-Mop 2 Pro, additionally prepare a soft brush for the lens (as for cameras.

💡

Before cleaning, take a picture of the location of the sensors on your model, which will help you not to confuse them when you reverse assemble them. Z10 Pro).

Step-by-step: how to disassemble the bumper and clean the sensors

The cleaning process can be divided into 3 steps: bumper removal, sensor cleaning and reverse assembly. The most difficult thing is to carefully remove the bumper without damaging the latches. Different Xiaomi models have different mounts, but the general principle is the same.

Step 1: Disconnecting and preparing the vacuum cleaner

Before disassembly it is necessary:

1. Turn off the vacuum cleaner with the power button.
2. Turn it upside down (so as not to scratch the lenses on the table).
3. Make sure the battery is at least 50% discharged, which will reduce the risk of short circuits in the event of accidental closure of contacts.

Step 2: Remove the bumper

The bumper is mounted on plastic latches and sometimes on 1–2 screws (in models of Roborock) S5/S6). Algorithm:

1. Find hidden grooves on the sides of the bumper (usually located closer to the wheels).
2. Carefully insert the plastic spatula into the groove and pull the bumper over yourself until you hear a click.
3. Repeat for all latches (usually 4-6). Do not force - if the bumper does not respond, look for hidden screws under stickers or rubber plugs.

For models with screws (for example, Xiaomi Mi Robot Vacuum) 1S):

1. Remove the side brushes (they are attached to one screw or latch).


2. Put rubber plugs on the bottom of the bumper - there are screws hidden underneath them.




3. Unscrew the screws with a cross screwdriver (usually a size T6 or T8).

Step 3: Cleaning the sensors

When the bumper is removed, you'll see 2-4 infrared sensors (small black or transparent "eyes") and sometimes micro-switches (metal contacts).

1. Blow the dust with compressed air (hold the balloon vertically so as not to splash liquid!).
2. Soak the cotton swab in isopropyl alcohol and gently wipe the sensor lenses in circular motions. Don't press!
3. For hard-to-reach places, use a toothpick wrapped with microfiber.
4. Micro-switch wipe dry napkin - alcohol can oxidize contacts.

If the sensors are covered with sticky plaque (for example, from cigarette smoke or kitchen fat), repeat the treatment with alcohol 2-3 times, allowing the surface to dry between approaches.

Step 4: Assembly and testing

After cleaning:

1. Let the sensors dry for 10-15 minutes (alcohol evaporates quickly, but it is better to be safe).
2. Set the bumper in place, starting with the top latches (they are usually fixed first).
3. Secure the side grooves by pressing the bumper before clicking.
4. Turn on the vacuum cleaner and check the reaction to obstacles manually (put your hand to the sensors - the robot must stop).

The bumper is cleared of dust on both sides|

All latches are in place and not broken.|

Sensors are dry and divorce-free|

The sleeves were slacked, but not slacked.|-->

⚠️ Attention: If the robot stopped responding to obstacles after cleaning, check if the sensor plumes disconnected during assembly. S7 And newer plumes are fastened with fragile latches - they are easy to damage.

Features of cleaning for different models Xiaomi and Roborock

Although the collision sensors operate in the same way, their layout and design vary depending on the model, and here are key differences that are important to consider:

For models with lifting 3D-sensor (e.g. Roborock) S7 MaxV) Be especially careful: this module is responsible not only for detecting obstacles, but also for recognizing objects (for example, shoes or wires.

If you have a Dreame Bot or a Viomi, these robots often combine collision sensors with ultrasonic sensors, and you can't clean them with alcohol, just with a dry wipe, because ultrasonic membranes are sensitive to moisture.

💡

In models with carpet recognition function (for example, Roborock) S7 MaxV Ultra: Collision sensors calibrate automatically every time you turn on. After cleaning, give the robot 1-2 minutes to self-test — don't interrupt the process!

Frequent mistakes when cleaning sensors and how to avoid them

Even experienced users sometimes make mistakes that cause sensors to break or deteriorate. TOP-5 Failures and How to Prevent Them:

• 🔧 Use of metal tools → Solution: Use only plastic shoulder blades or mediators, and in extreme cases, the blunt side of a table knife wrapped in a napkin.

Another common mistake is to clean the sensors by eye, without a flashlight. Many of the contaminants (such as a thin layer of fat) are not visible in normal light, but they have a big impact on the sensors. Always look at the sensors at an oblique angle, so you can see the stains and dust.

⚠️ Warning: If after cleaning, the robot started spiraling or hanging in one place, you probably damaged the gyroscope (located next to the collision sensors in some models), in which case only flashing or replacing the module will help.

What to do if cleaning doesn’t work: alternative solutions

If the robot still doesn't see obstacles well after cleaning the sensors thoroughly, the problem may be deeper.

1. Verification of software settings

Sometimes sensor failures are not due to physical contamination, but to incorrect settings in the application.

• Settings → Navigation → Sensor sensitivity (in some models, this parameter is called Collision sensitivity).
• Settings → Maps. → Sensor calibration (available for LiDAR robots).

If sensitivity is minimal, the robot will ignore small obstacles, try to increase the value by 1-2 points and test.

Diagnosis of mechanical damage

If the sensors are clean, but the robot is still not responsive to obstacles, check:

• 🔧 Bumper integrity – cracks or deformations can block micro-switches from operating.
• 🔌 The state of plumes - in Roborock models S5/S6 sensor plumes are often rubbed against the body.
• 📏 Clearances between bumper and body – if bumper “sank”, sensors may not work.

3. Resetting and flashing

In rare cases, sensor glitches cause software failures.

1. Reset the settings to factory (Settings) → General. → Reset).
2. Update the firmware through the Mi Home or Roborock app.
3. If the robot “hangs” on the boot screen, perform a forced flashing through USB-OTG (For specific instructions for a particular model, look for forums 4PDA Xiaomi Community).

Replacement of sensors

If all of the above methods didn't work, it's likely that one or more sensors failed.

• Buy original sensors (the articles can be found in service manuals or on AliExpress using the robot model).
• You'll need a soldering iron (subsidized to the board) and experience with electronics to replace it.
• The cost of replacing sensors in the service: from 1,500 to 3,000 rubles (depending on the model).

For robots older than 3-4 years, replacing sensors can be unprofitable - it is cheaper to buy a new model. S8 Pro Ultra, where the cost of repair is justified.

Prevention: how to extend the life of collision sensors

To avoid cleaning the sensors every 2-3 months, follow the following simple rules of care:

• 🧹 Rub the bumper regularly with a wet wipe (1 time per week) to prevent the buildup of sticky dust.
• 🚫 Do not use the vacuum cleaner in dusty spaces (for example, during repairs). fine construction dust penetrates the inside of the housing and settles on sensors.
• 🍳 Keep the robot away from the kitchen while cooking. Fat fumes quickly coat the sensor lenses with film.
• 🐕 Clean the side brushes after each cleaning - they are wound with hair, which then falls on the sensors.
• ☀️ Keep the vacuum cleaner dry. Humidity accelerates the oxidation of the micro-switch contacts.

For models with laser sensors (LiDAR) additionally:

• 🔦 Once a month, wipe the rotating LiDAR head with a dry wipe (without touching the lens!).
• 🚪 Do not use a robot in rooms with mirror walls – it knocks laser navigation.

If you have pets at home, you will have to clean the sensors more often – wool and dandruff are especially quick to clog sensors, in which case it is recommended to use bumper cases (sold on AliExpress), which partially protect the sensors from contamination.

💡

Cleaning the sensors regularly not only improves navigation, but also prolongs battery life, and when the robot constantly stumbles on furniture, it spends extra energy on repeated attempts to detour, which leads to a faster discharge.

FAQ: Answers to Frequent Questions About Collision Sensors