DC Pump Motor Speed Control via Adaptive PWM Duty Cycle
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Solution Overview
Problem
DC pump motors used for lubricant pumping face challenges in operating effectively under varying conditions, such as different voltages and temperatures, leading to unsteady performance and inconsistent lubricant delivery, especially in applications lacking rotational speed sensors.
Innovation Solution
A control unit that uses a pulse-width modulated (PWM) control signal with an adaptive duty cycle, based on real-time acquisition of input voltage, motor current, and temperature, to maintain a constant rotational speed without the need for rotational speed sensors, allowing operation across different conditions and voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If rotational speed sensors are used to maintain constant motor speed under varying conditions, then speed control precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces mechanical/physical sensors (rotational speed sensors) with an electronic control approach using PWM duty cycle adjustment based on acquired operating parameters. The control unit determines appropriate duty cycles through calculation based on voltage, current, and temperature data, eliminating the need for additional sensing hardware while maintaining speed control capability.
Solution Approach 2:
The system uses its own existing sensors (voltage, current, temperature) to self-regulate motor speed without requiring external speed sensing. The control unit leverages already-acquired operating parameters to automatically adjust PWM duty cycle, making the system self-sufficient in maintaining constant speed.
2Manufacturing precision
If DC pump motors are designed for specific operating conditions with fixed control parameters, then manufacturing precision is improved, but adaptability to different operating conditions deteriorates
Solution Approach 1:
The patent implements dynamic control parameters that automatically adjust based on real-time operating conditions. The control unit acquires voltage, current, and temperature data and calculates PWM duty cycles dynamically to maintain constant motor speed across varying conditions, transforming fixed control into adaptive control.
Solution Approach 2:
The system changes control parameters (PWM duty cycle) based on acquired operating parameters (voltage, current, temperature). By adjusting the duty cycle according to actual operating conditions, the motor maintains constant speed despite variations in supply voltage, load, or temperature.
3Stability of the object's composition
If PWM duty cycle is adjusted frequently to maintain constant speed under varying conditions, then speed stability is improved, but energy consumption increases
Solution Approach 1:
The patent implements continuous monitoring and adjustment of PWM duty cycle based on real-time acquisition of operating parameters. The control unit continuously adapts the duty cycle to maintain constant motor speed, ensuring uninterrupted and stable operation without energy-wasting idle adjustments or corrections.
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
Ensures stable, quiet, and reliable lubricant supply with precise volume delivery, reducing costs by eliminating the need for rotational speed sensors and accommodating varying operating conditions.
Implementation Method 1
The object is solved, for example, by a method for controlling a DC pump motor, preferably a brushed DC motor for pumping lubricant, which is controlled by a pulse-width modulated (PWM) control signal
Implementation Method 2
by reducing the overall duty cycle, i.e. after integration due to the low-pass effect of the motor coils, a lower effective voltage is applied to the DC pump motor
Data Source
AI summary
A method for controlling a DC pump motor, preferably a brushed DC motor for pumping lubricant, which motor is controlled by a pulse-width modulated (PWM) control signal, wherein current parameters are acquired in an acquisition step and a duty cycle (D) of the PWM control signal (SPWM) is adapted and/or changed on the basis of the detected parameters in an adaptation step, wherein the acquisition of current parameters comprises at least the acquisition of a current input voltage (UB).