Robot Cleaner Driving Unit with Constant Traction Force on Steps
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Solution Overview
Problem
Conventional robot cleaners face challenges in maintaining a constant traction force for their driving wheels, especially when navigating surfaces with steps or varying conditions, due to the elastic force changes in conventional elastic members used to press the wheels against the floor.
Innovation Solution
A driving unit design featuring a housing, a driving motor, a rotating driving arm that supports the driving wheel, and an elastic member supported between a first and second support point, where the angle between these points is maintained at an acute angle, ensuring a consistent traction force regardless of the wheel's position relative to the robot cleaner's body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional elastic members (tension coil spring) are used to press the driving wheels toward the floor surface, then the driving wheels can generate frictional force for traction, but the elastic force changes significantly with displacement, causing large variations in traction force when the robot cleaner moves on surfaces with steps
Solution Approach 1:
The patent changes the geometric parameters of the elastic member configuration, specifically the attachment points and orientation, to maintain a substantially constant angle (θ) between the elastic member and the driving arm throughout rotation. This parameter optimization ensures that the elastic force component contributing to traction remains stable even as the driving wheel moves through different positions, thereby resolving the contradiction between generating sufficient frictional force and maintaining force constancy.
Solution Approach 2:
The patent employs a rotating driving arm mechanism that dynamically adjusts the position of the driving wheel relative to the robot cleaner body. As the driving arm rotates, the elastic member's orientation changes in a controlled manner, maintaining a substantially constant angle with the driving arm. This dynamic configuration allows the system to adapt to varying floor conditions (including steps) while keeping the traction force stable, overcoming the limitation of conventional fixed elastic members.
2Adaptability or versatility
If the driving wheel protrudes downward from the main body to maintain contact with the floor surface on steps, then the robot cleaner can navigate various floor conditions, but the displacement of the driving wheel changes, causing significant variation in elastic force and traction force
Solution Approach 1:
The rotating driving arm provides dynamic adaptability, allowing the driving wheel to protrude downward when needed to maintain floor contact on steps or uneven surfaces. Simultaneously, the elastic member's orientation is maintained at a substantially constant angle throughout the rotation, ensuring that the traction force remains stable despite the changing position. This dynamic mechanism resolves the contradiction between adaptability and force consistency.
Solution Approach 2:
The elastic member is pre-configured with specific attachment points and orientation angles that anticipate the range of motion of the driving arm. By designing the system so that the angle (θ) remains substantially constant throughout the expected rotation range, the patent ensures that traction force is maintained without requiring active control adjustments, thereby achieving both adaptability and force consistency.
3Device complexity
If the elastic member is configured with fixed support points, then the structure is simple, but the traction force varies significantly when the driving arm rotates and the driving wheel changes position
Solution Approach 1:
The patent optimizes the geometric parameters of the elastic member configuration, specifically selecting attachment points and orientations that maintain a substantially constant angle (θ) during driving arm rotation. This parameter optimization achieves traction force stability without adding complex mechanisms, as the solution is embedded in the geometric design of the elastic member's support points and orientation.
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
This design maintains a constant traction force for the driving wheel both when it protrudes and when it is seated, ensuring stable and continuous operation on various floor conditions, including surfaces with steps.
Implementation Method 1
the elastic members have a big difference in a force which presses the driving wheels due to change in an elastic force depending on the displacement of the driving wheels
Implementation Method 2
the driving wheels drive a robot cleaner body using a frictional force generated between the driving wheels and a floor surface being in contact therewith
Data Source
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AI summary
Disclosed herein are a robot cleaner 1 having a driving unit 600. The robot cleaner 1 has a configuration in which an elastic member 640 is supported so that an angle formed between the elastic member 640 and a rotation shaft 633 of the driving unit 600 is provided in a predetermined range to offset a decrease in an elastic force generated while the robot cleaner 1 is driving on a surface having steps and a driving wheel 610 protrudes downward from the robot cleaner 1. Accordingly, there is the effect where a traction force is maintained at a predetermined level for maintaining the driving performance of the robot cleaner 1 even while the robot cleaner 1 is driving and the driving wheel 310 is lowered to decrease the elastic force of the elastic member 340.