Robot mower occasionally bumps hard into obstacles instead of gently touching and turning away.

Safety: Turn OFF the mower before inspecting the bumper and sensors.

• Check bumper travel: Press the bumper at multiple points and ensure it moves freely and springs back.
• Clean sensors: Wipe ultrasonic sensor windows and remove any dirt or grass.
• Inspect springs and mounts: Replace broken bumper springs or mounts that prevent early detection of obstacles.
• Test with known obstacle: In a controlled area, place a soft object (e.g., foam block) and observe how the mower reacts. If impact is still hard, the bumper or sensor module may need replacement.