Rotating Optical Cover Cleaning for Dirty ADAS Sensors
Solution Overview
Problem
Existing driver assist systems struggle to effectively clean optical sensors exposed to exterior dirt, particularly stubborn deposits, without requiring vehicle movement or complex image processing, and lack automatic dirt detection.
Innovation Solution
A method and system that uses a rotating optical element upstream of the sensor to detect circular or semi-circular shapes indicative of dirt through image processing, triggering cleaning actions such as rotation speed changes, fluid spraying, or wiper usage, regardless of vehicle motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the optical sensor is installed outside the vehicle to improve the field of view, then the viewing angle is optimized, but the optical sensor becomes exposed to dirt and pollutants that reduce effectiveness
Solution Approach 1:
The system separates the optical sensor from its protective covering by detecting dirt on the protective cover independently and triggering separate cleaning actions. The protective cover and sensor are treated as distinct components that can be cleaned separately, allowing the sensor to remain protected while maintaining cleaning effectiveness.
Solution Approach 2:
The system performs preliminary dirt detection on the protective cover before cleaning the optical sensor. By detecting dirt patterns on the cover first and using this information to trigger appropriate cleaning actions, the system prepares the cleaning process in advance rather than reacting to sensor degradation.
2Ease of operation
If vibration means are used to clean the protective glass, then some dirt removal is achieved, but stubborn and encrusted dirt remains ineffective
Solution Approach 1:
The system dynamically adjusts the cleaning approach based on detected dirt characteristics. Instead of using fixed vibration amplitude, the system varies vibration intensity and duration based on the severity and type of dirt detected, enabling effective removal of both light and stubborn deposits.
Solution Approach 2:
The system employs mechanical vibration of the protective cover at controlled amplitudes and frequencies to dislodge dirt particles. The vibration is applied in conjunction with image processing feedback to target areas with stubborn dirt that requires mechanical disruption.
3Productivity
If the protective optical element is rotated to remove dirt using centrifugal force, then cleaning is achieved, but dirt at certain points remains undetected and unremoved
Solution Approach 1:
The system continuously monitors the protective cover during rotation using image processing to detect dirt patterns. The feedback from image analysis triggers adjustments in rotation speed and cleaning actions, ensuring that dirt in all areas including hard-to-reach points is detected and removed.
Solution Approach 2:
The system changes operational parameters such as rotation speed and vibration amplitude based on detected dirt conditions. When dirt is detected in areas with weak centrifugal effect, the system increases rotation speed or applies additional vibration to enhance cleaning effectiveness.
4Measurement precision
If image processing is used to detect dirt by comparing multiple images, then dirt detection is possible, but the method is long and complex and requires vehicle movement
Solution Approach 1:
The system extracts the dirt detection function from the optical sensor images and applies it to the protective cover images instead. By analyzing the cover surface directly for dirt patterns, the system simplifies the detection process and eliminates the need for complex multi-image comparison and vehicle movement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables automatic and efficient cleaning of optical sensors by detecting and removing dirt promptly, maintaining system operability and reducing manual intervention.
Implementation Method 1
the optical element is intended to be rotated by an actuator, so as to remove any dirt by virtue of the centrifugal force associated with the rotation of this optical element
Implementation Method 2
processing means configured to process a succession of images acquired by the optical sensor when the optical element is rotating, so as to detect a general circular or semi-circular shape on the acquired images
Data Source
AI summary
The present invention relates to a method for cleaning a protective device (3) for a drive assist system (1), comprising an optical sensor (13) having an optic (14), the protective device (3) having an optical element (9) arranged upstream of the optic (14) and having an inner surface (9a) and an outer surface (9b) and being movably mounted about an axis of rotation (A1), the method comprising the following steps: processing a succession of images acquired by the optical sensor (13) when the optical element (9) is rotating, so as to detect a generally circular or semi-circular shape which is centred on the axis of rotation (A1) of the optical element (9) and which is generated by dirt deposited on the outer surface (9b), and triggering at least one action for cleaning the outer surface (9b) of the optical element (9) if the shape is detected. The invention also relates to an associated drive assist system (1).