Motor Speed Curve Control Circuit Linearization

Solution Overview

Problem

Traditional motor speed control circuits face inaccuracies due to non-linear motor speed curves, making precise control of motor speed challenging and unstable.

Innovation Solution

A motor speed curve control circuit comprising a divider resistor module, an analog-to-digital converter, and an arithmetic unit that generates a second pulse width modulation signal to adjust the slope of the motor speed curve, making it multi-stage and linear, allowing for precise control of motor speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a traditional non-linear motor speed curve is used, then the control circuit can operate with simple hardware, but the control precision and accuracy of motor speed are insufficient

Engineering Contradiction:

Improvecontrol precisionVSAvoidcontrol circuit complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The motor speed curve is divided into multiple linear segments (first slope, second slope, third slope) with different gradients. Each segment corresponds to a specific duty cycle range and speed range, allowing precise control within each segment while maintaining overall curve accuracy. The divider resistor module generates multiple turning-point voltages that define these segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The control circuit dynamically selects which linear segment to use based on the current operating point (duty cycle and speed). The arithmetic unit calculates the appropriate slope selection according to the current duty cycle, enabling the system to adaptively switch between different linear approximations to maintain high precision across the entire operating range.

Inventive Principle:

Principle #15Dynamics

2Stability of the object's composition

If a non-linear motor speed curve is used, then the hardware structure remains simple, but the stability of motor speed control deteriorates

Engineering Contradiction:

Improvestability of motor speedVSAvoidcontrol circuit structure

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The motor speed curve is divided into multiple linear segments (first slope, second slope, third slope) with different gradients. Each segment corresponds to a specific duty cycle range and speed range, allowing precise control within each segment while maintaining overall curve accuracy. The divider resistor module generates multiple turning-point voltages that define these segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The control circuit changes the slope parameter of the speed curve based on the operating region. By selecting different linear segments with appropriate slopes for different duty cycle ranges, the system optimizes stability for each operating condition while maintaining a relatively simple hardware structure.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If a non-linear motor speed curve is used, then the control circuit design is simple, but the ease of controlling motor speed is reduced

Engineering Contradiction:

Improveease of controlling motor speedVSAvoidcontrol circuit design

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The motor speed curve is divided into multiple linear segments (first slope, second slope, third slope) with different gradients. Each segment corresponds to a specific duty cycle range and speed range, allowing precise control within each segment while maintaining overall curve accuracy. The divider resistor module generates multiple turning-point voltages that define these segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The control circuit dynamically selects which linear segment to use based on the current operating point (duty cycle and speed). The arithmetic unit calculates the appropriate slope selection according to the current duty cycle, enabling the system to adaptively switch between different linear approximations to maintain high precision across the entire operating range.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS9602036B2Motor speed curve control circuit and moter thereof

Publication Date: 2017.03.21 ANPEC ELECTRONICS CORPORATION

AI summary

The present disclosure illustrates a motor speed curve control circuit. The motor speed curve control circuit is configured for adjusting a speed of a motor according to a motor speed curve. The motor speed curve control circuit comprises a divider resistor module, an analog-to-digital converter and an arithmetic unit. The resistor module is configured for generating at least one turning-point voltage. The turning-point voltage is used to adjust a slope of the motor speed curve. The analog-to-digital converter converts the turning-point voltage to digital form. The arithmetic unit sets a speed associated with the turning-point voltage corresponding to a first preset duty cycle in the motor speed curve, such that the motor speed curve becomes linear. The arithmetic unit generates a second pulse width modulation signal according to the adjusted motor speed curve and a first pulse width modulation signal to drive the motor.