Robot Cleaner Shielding Module for Collision Detection Sensitivity
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Solution Overview
Problem
Existing robot cleaners face issues with collision detection sensitivity and reliability due to the bumper covering the cliff sensor, leading to inadequate recognition of collision events when the bumper does not retract by an effective distance.
Innovation Solution
A robot cleaner with a shielding module that includes a cam and cover plate, rotating around a shared shaft, to expose and cover the cliff sensor based on bumper movement, enhancing sensitivity and reliability of collision detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the bumper is moved inward by an external force to detect collision, then the collision detection function is activated, but the sensor fails to recognize the bumping operation when the bumper is not sufficiently retracted by an effective distance
Solution Approach 1:
Instead of using the bumper's inward movement to directly trigger detection, the invention uses the cliff sensor's light receiving portion to detect the reflected light from the bumper's outer surface. When the bumper moves inward, the light path changes, causing the light receiving portion to no longer receive the reflected light, thereby detecting the collision. This inverts the traditional detection approach and solves the sensitivity issue.
Solution Approach 2:
The invention introduces light as an intermediary between the bumper movement and the detection system. The light emitting portion emits light that reflects off the bumper's outer surface to the light receiving portion. When the bumper moves inward, this light path is interrupted, providing a sensitive and reliable collision detection mechanism that works even with small bumper movements.
2Reliability
If the cliff sensor is exposed downward to detect terrain below, then the terrain detection function is enabled, but the sensor cannot detect collision when the bumper covers it
Solution Approach 1:
The cliff sensor serves dual functions: detecting terrain below when the bumper is in its outer position, and detecting collision when the bumper moves inward and blocks the light path. The light emitting portion and light receiving portion work together to provide both terrain detection and collision detection capabilities through the same sensor assembly.
Solution Approach 2:
The system dynamically switches between terrain detection and collision detection modes based on the bumper's position. When the bumper is outward, the cliff sensor detects terrain; when the bumper moves inward, the same sensor detects collision through the changed light path. This dynamic functionality resolves the contradiction between maintaining terrain detection and enabling collision detection.
3Measurement precision
If the bumper is disposed to cover the cliff sensor when moved inward, then collision detection is enabled, but the detection sensitivity is insufficient when the bumper is not sufficiently retracted
Solution Approach 1:
The invention replaces the mechanical contact-based detection system with an optical detection system. Instead of relying on the bumper's mechanical movement to trigger a switch or sensor, the system uses light emission and reflection to detect bumper position and collision. This substitution provides much higher sensitivity and reliability, as even small bumper movements that block the light path are easily detected.
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
The shielding module improves the sensitivity and reliability of collision detection by ensuring faster cover plate rotation covers the cliff sensor after bumper contact, allowing precise obstacle detection in various collision directions.
Implementation Method 1
the cliff sensor includes a light emitting portion and a light receiving portion, and the controller is configured to measure a time at which light irradiated downward from the light emitting portion is received by the light receiving portion to detect the terrain below
Implementation Method 2
a shielding module that includes a cam and cover plate, rotating around a shared shaft, to expose and cover the cliff sensor based on bumper movement
Data Source
AI summary
A robot cleaner having a shielding module provided under a cleaner body is provided. The shielding module includes a cam and a hiding plate which rotate with the same phase angle about a same rotating shaft. The distance between the center of the hiding plate and the center of the rotating shaft is longer than the distance between a contact point on a cam surface of the cam and the center of the rotating shaft. A guide protrusion of a bumper is in contact with the cam surface at the contact point. Therefore, the rotation movement speed of the hiding plate which rotates to hide a cliff sensor is much faster than the inner movement speed of the bumper, thereby improving sensitivity to the detection of a collision between the bumper and an obstacle by using the cliff sensor.