Robot Cleaner Mop Moisture Detection via Drive Motor Current
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Solution Overview
Problem
Existing robot cleaners performing wet cleaning lack a cost-effective method to detect the water quantity in their rotary mops, relying on separate sensors which increase equipment costs and complexity.
Innovation Solution
A control method that uses the output current of the drive motor to determine the water quantity in the rotary mop, eliminating the need for a separate water quantity sensor by setting threshold values and fusion of pump operating states to assess water sufficiency, and adjusts cleaning modes accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate water quantity sensor is used to detect water levels in the rotary mop, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines the water quantity detection function with the existing motor control system by using the motor's output current as a proxy indicator. Instead of adding a separate sensor, the system merges the detection function into the motor controller, which already monitors current for control purposes. The controller analyzes current variations to infer water quantity on the rotary mop, thereby eliminating the need for additional sensing hardware while maintaining detection capability.
Solution Approach 2:
The motor serves a dual function: it not only drives the rotary mop but also provides self-diagnostic information through its output current characteristics. The system leverages the motor's inherent electrical properties to detect water quantity, allowing the motor to 'self-report' on the operational condition without requiring external sensing devices. This self-service approach reduces system complexity while enabling water quantity monitoring.
2Reliability
If multiple separate sensors are added to detect floor state and water quantity, then reliability is improved, but device complexity increases
Solution Approach 1:
The motor controller is designed to perform multiple functions: it controls motor operation, monitors output current, detects water quantity on the rotary mop, and determines floor state. By making the controller universal and multi-functional, the system eliminates the need for separate dedicated sensors for each detection task. The same controller hardware and processing unit handle all monitoring and detection functions, reducing overall system complexity while maintaining comprehensive monitoring capability.
Solution Approach 2:
The patent merges multiple detection functions (water quantity sensing and floor state detection) into the existing motor control system. The controller analyzes motor current characteristics to simultaneously infer both water quantity on the rotary mop and floor conditions, combining what would traditionally require separate sensor systems into a single integrated control function.
3Manufacturing precision
If water supply is increased to ensure adequate moisture, then cleaning quality is improved, but energy consumption increases
Solution Approach 1:
The system implements feedback control by continuously monitoring motor output current and using this information to adjust water supply levels. The controller analyzes current variations that indicate the actual water quantity on the rotary mop and adjusts the pump operation accordingly. This closed-loop feedback ensures that water is supplied only when needed and in the precise amount required, optimizing cleaning effectiveness while minimizing energy consumption from the water pump.
Solution Approach 2:
The water supply system transitions from a static, fixed-rate supply to a dynamic, variable-rate supply controlled by real-time motor current analysis. The controller dynamically adjusts pump operation based on detected water quantity and cleaning conditions, allowing the system to adapt water supply levels to actual needs rather than operating at constant maximum output, thereby reducing unnecessary energy consumption.
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 approach allows for cost-effective and efficient detection of water levels, enabling the robot cleaner to switch between wet and dry cleaning modes, reducing equipment costs and improving operational efficiency by using the output current of the drive motor to determine water sufficiency and floor state.
Implementation Method 1
a controller configured to determine whether the water in the water tank is insufficient by reading the output current of the drive motor to determine the water content of the rotary mop
Data Source
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AI summary
A robot cleaner of the present disclosure includes: a robot cleaner including: a main body configured to form an outer shape; a water tank configured to contain water; a pair of rotary mop configured to move the main body while rotating in contact with a floor; a drive motor configured to rotate the pair of rotary mop; a pump configured to be connected to the water tank and drive a nozzle that inject the water to the rotary mop; and a controller configured to determine whether the water in the water tank is insufficient by reading the output current of the drive motor to determine the water content of the rotary mop when the pair of rotary mops rotate. Therefore, it is possible to provide the robot cleaner that is effective in cost and space utilization because it does not have a separate water quantity sensor and can measure the water quantity of the rotary mop of the robot cleaner.