Adaptive Flow Control via Motor Speed Feedback
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Solution Overview
Problem
Commercial and industrial systems face increased complexity and costs due to the need for multiple feedback sensors to achieve precise fluid delivery, which can be costly and difficult to maintain.
Innovation Solution
A system using a pump controller that adjusts the motor duty cycle based on the measured drive speed of a fixed-displacement fluid pump, utilizing low-cost sensors like a reed switch to provide operational feedback, thereby reducing the need for direct measurements of flow rate, temperature, or pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple feedback sensors are added to measure flow rate, temperature, pressure, and viscosity, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the control approach from direct fluid parameter measurement to motor parameter measurement. Instead of measuring flow rate, temperature, pressure, and viscosity directly, the system measures only motor speed and infers pump performance from motor operational parameters, thereby eliminating multiple sensors while maintaining control accuracy
Solution Approach 2:
The patent introduces motor operational parameters as an intermediary measurement. Rather than directly measuring difficult-to-obtain fluid parameters, the system uses easily measurable motor speed and current as intermediaries to infer pump performance and achieve accurate fluid delivery control
2Measurement precision
If multiple feedback sensors are added to measure flow rate, temperature, pressure, and viscosity, then measurement precision is improved, but implementation cost increases
Solution Approach 1:
The patent extracts the control approach from direct fluid parameter measurement to motor parameter measurement. Instead of measuring flow rate, temperature, pressure, and viscosity directly, the system measures only motor speed and infers pump performance from motor operational parameters, thereby eliminating multiple sensors while maintaining control accuracy
Solution Approach 2:
The patent replaces expensive, complex fluid measurement sensors with inexpensive motor parameter sensors. The system uses low-cost motor speed sensors and leverages existing motor current measurements, eliminating the need for costly flow meters, temperature sensors, pressure sensors, and viscosity sensors
3Measurement precision
If multiple feedback sensors are added to measure flow rate, temperature, pressure, and viscosity, then measurement precision is improved, but maintenance difficulty increases
Solution Approach 1:
The patent extracts the control approach from direct fluid parameter measurement to motor parameter measurement. Instead of measuring flow rate, temperature, pressure, and viscosity directly, the system measures only motor speed and infers pump performance from motor operational parameters, thereby eliminating multiple sensors while maintaining control accuracy
4Adaptability or versatility
If duty cycle is adjusted based on measured drive speed feedback, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent implements feedback control by measuring motor speed and using it to adjust the duty cycle. The controller compares measured motor speed with target motor speed and modifies the duty cycle accordingly, creating a closed-loop system that adapts to changing conditions while maintaining simple implementation
Solution Approach 2:
The patent changes the control parameter from direct fluid parameter control to motor operational parameter control. By adjusting the duty cycle based on motor speed feedback, the system achieves adaptive control through simple parameter modification rather than complex multi-parameter regulation
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 enables cost-effective adaptive control of fluid pumps, decreasing implementation and maintenance costs while achieving target flow rates by incorporating the effects of load and environmental factors into motor operation.
Implementation Method 1
a sensor configured to sense a parameter related to a drive speed of the motor
Data Source
AI summary
A system includes a fixed-displacement fluid pump, a motor operatively connected to the fixed-displacement fluid pump, a sensor configured to sense a parameter related to a drive speed of the motor, and a user interface. The pump controller is configured to receive an input from the user interface of a target flow rate of the pump, determine a duty cycle for the motor based on the target flow rate, and control the motor to operate according to the duty cycle. The pump controller is further configured to receive an indication of the sensed parameter related to the drive speed of the motor, determine a measured drive speed of the motor based on the sensed parameter, and iteratively adjust the duty cycle based on a difference between the measured drive speed of the motor and an expected drive speed of the motor.