An Autel Obstacle Avoidance Error Code indicates that the aircraft’s visual perception system or millimeter-wave radar cannot accurately calculate obstacle distance, map spatial depth, or execute collision-avoidance braking. When this alert triggers, the drone either disables automated braking, restricts flight speed, or stops moving forward because it detects false obstacles. To resolve it, clean the binocular optical lenses, move out of direct glare or low light, verify your flight mode, and ensure sensor paths are unobstructed.
Fast Fix
Power down the aircraft and wipe all binocular vision lenses using a clean optical microfiber cloth. Ensure no third-party accessories or propeller guards obstruct the sensors’ field of view. Check that the drone is not in Ludicrous (Sport) mode, which disables avoidance by design, and restart the drone in an open, evenly lit outdoor space.
Quick Safety Snapshot
- Severity: Moderate to High
- Safe to Fly: Conditionally (manual flight remains possible, but automatic braking and proximity stops are offline)
- Primary Cause: Dirty or smudged optical lenses, extreme light contrast (direct sun glare), operating in low light, or sensor calibration drift
- Immediate Action: If the error appears mid-flight or causes erratic braking, toggle obstacle avoidance to manual bypass or switch to standard manual control. Maintain extra clearance from all structures and land safely.
What the Obstacle Avoidance Error Means
Autel drones (including the EVO II, EVO Lite, EVO Nano, and EVO Max series) rely on pairs of stereoscopic binocular cameras located on the front, rear, sides, top, and bottom of the airframe to create a 3D depth map of their surroundings.
When the perception system functions normally:
- The cameras capture overlapping real-time images.
- The onboard vision processor compares the pixel disparity between the paired lenses to calculate the exact distance to nearby objects.
- If an object enters the safety buffer, the flight controller commands the motors to brake or chart an automated bypass route.
If the processor receives distorted, overexposed, or misaligned visual frames, it cannot calculate reliable distance vectors. To prevent an uncontrolled crash, the system flags an Obstacle Avoidance Error and either disables avoidance or freezes the aircraft in a stationary hover.
Diagnostic Path: Pinpointing the Failure Mode
Isolate the condition causing the avoidance system to fail:
Obstacle Avoidance Alert Triggered
│
Does the Drone Brake Abruptly with No
Obstacle Present? (Ghosting)
│
┌──────────────┴──────────────┐
▼ ▼
YES NO
│ │
Check Sun Glare and Check Flight Mode
Optical Lens Cleanliness & App Warning Status
│ │
• Low Sun Angle / Glare? • Ludicrous Mode Active?
• Clean Smudges/Fingerprints (Avoidance Disabled)
• Inspect for Scratched Glass • Vision Sensor Hardware Error?
1. “Phantom” Braking (Drone Stops Mid-Air in Clear Space)
If the drone repeatedly stops, jerks, or refuses forward stick commands on a clear day:
- Direct sunlight striking a binocular lens at a low angle creates optical flaring that the processor interprets as a solid obstacle.
- Flying over highly reflective, featureless surfaces—such as calm water, snowfields, or polished tile—breaks the disparity algorithm.
- Fingerprint oil or dust on the lens scatters incoming light, creating false proximity readings. For advice on handling false readings, see Obstacle Avoidance “Phantom Objects”: Recalibrating for Clear Paths.
2. Avoidance Unavailable or Grayed Out in the App
If the obstacle avoidance toggle in the Autel Explorer app is disabled:
- Check your current flight speed mode. In Ludicrous Mode (or Sport Mode), obstacle avoidance is automatically turned off to allow maximum flight speed and aggressive tilt angles.
- If the app displays an underlying hardware or perception initialization failure, the problem lies in the core optical sensor bus. Refer to Autel Error Code 102400 Vision Sensor Error.
3. Low-Light Lockout
Autel optical avoidance systems require adequate ambient illumination to discern spatial contrast. If you fly at dusk, dawn, or in shadowed indoor locations, the app will report that obstacle sensing is degraded or unavailable due to insufficient light.
Step-by-Step Troubleshooting
Step 1: Clean and Inspect All Optical Windows
- Power down the drone.
- Inspect every sensor port (front, back, bottom, and side arrays depending on your EVO model).
- Use a lens brush or compressed air to remove loose abrasive grit.
- Wipe each glass surface using a lint-free microfiber cloth dampened with optical cleaning fluid. For proper cleaning techniques, see Cleaning Vision Sensor Lenses: Smudges vs. Scratches in Calibration.
- Inspect the lenses under a flashlight for deep scratches. Scratches refract light permanently and will cause persistent obstacle errors.
Step 2: Configure App Avoidance Behavior
Verify your software settings in the Autel Explorer app:
- Tap the Settings gear icon and go to the Safety (or Flight Control) tab.
- Find the Obstacle Avoidance section.
- Verify the system is enabled.
- Toggle between Braking (the drone stops in front of an obstacle) and Bypass (the drone routes around it). If bypass algorithms struggle in dense environments, switch to Braking to simplify processing loads.
- Review the custom obstacle warning and stop distances; setting stop distances too high can cause the drone to refuse flight in normal operating areas.
Step 3: Recalibrate the Vision Sensor Array
If the error occurs in clear weather on clean lenses, the stereo cameras have drifted out of mechanical or optical alignment:
- Connect the aircraft to a PC running the official Autel PC Tool.
- Run the full visual positioning calibration routine using an external monitor.
- If the utility reports an alignment failure, follow the step-by-step fixes in Autel Vision Sensor Calibration Error Code.
Step 4: Rule Out Third-Party Hardware Obstructions
- Remove any snap-on landing gear extensions, searchlights, payload droppers, or propeller guards.
- Even if an accessory does not directly cover the lens, it can enter the wide-angle peripheral field of view when the drone tilts forward under acceleration, triggering an immediate emergency stop.
Common Misdiagnoses
- Confusing Transmission Stutter with Obstacle Braking: When video transmission lags, pilots sometimes mistake the delayed camera response for the aircraft pausing or hesitating. Check the app flight telemetry: if ground speed remains steady while the video freezes, you are dealing with image transmission issues, not obstacle avoidance. See Autel Explorer App No Camera View or Video Transmission Error.
- Confusing GPS Mode Drops with Vision Failures: When a drone drops from GPS to ATTI mode, it drifts with the wind, which can look like an avoidance steering error. If the drone fails to hold hover position, check your satellite reception and navigation health via Autel Navigation System Error Code.
Hard Stops: When to Ground the Aircraft
Do not rely on obstacle avoidance and discontinue flight testing if:
- A vision sensor lens is cracked or pushed inward following an impact (see Autel Sensor Error After Crash).
- The drone engages in uncontrollable emergency braking during calm, forward flight in open air, presenting a flyaway or crash hazard.
- The Autel Explorer app reports a permanent sensor communication timeout that does not clear after a firmware refresh.