Motor Driving Control Device Torque Detection via PWM Duty Cycle
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Solution Overview
Problem
Conventional motor driving control devices for brushless motors lack convenience in torque control and efficiency, particularly in detecting and managing motor torque, which can lead to delayed control responses due to noise filtering and increased complexity.
Innovation Solution
A motor driving control device with a control unit that operates in vector control mode, utilizing a digital circuit for calculation processing, includes a state signal output unit that generates a pulse width modulation signal based on a triangular wave for indicating torque, allowing for real-time torque direction and magnitude determination, and a signal input unit that determines the rotation direction from input signals, reducing the need for multiple ports and wires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional motor driving control devices use noise filtering for torque detection, then measurement reliability is improved, but response time increases and productivity decreases
Solution Approach 1:
The patent extracts the torque detection function from the conventional noise-filtering process and implements it directly through PWM duty cycle analysis. The control unit reads the PWM duty cycle value from the PWM generation unit, which directly reflects the torque command value without requiring separate torque detection and noise filtering processes. This extraction eliminates the time delay associated with conventional noise filtering while maintaining reliable torque information.
Solution Approach 2:
The patent applies preliminary action by pre-calculating and embedding torque information into the PWM duty cycle value during the PWM generation process. The torque command value is converted into PWM duty cycle values in advance, so that the torque information is already prepared and available when needed for control decisions, eliminating the need for real-time torque detection and filtering.
2Ease of operation
If conventional motor driving control devices use multiple ports for control signals, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by making the single control unit perform multiple functions: it generates PWM signals for motor control, extracts torque information from PWM duty cycles, detects rotation direction from input signals, and executes torque hold control. This multi-functionality consolidates what would traditionally require multiple separate ports and control circuits into a single integrated control unit, reducing device complexity while maintaining ease of operation.
Solution Approach 2:
The patent merges the torque detection function, PWM generation function, and control decision-making function into a single control unit. The control unit reads PWM duty cycle values from the PWM generation unit and directly uses them for torque hold control without requiring separate torque detection ports or additional wiring. This merging eliminates the need for multiple ports and reduces circuit complexity.
3Measurement precision
If conventional motor driving control devices filter torque signals, then measurement precision is improved, but productivity decreases
Solution Approach 1:
The patent replaces the mechanical noise filtering process with a digital signal processing approach. Instead of using hardware filters that physically process and delay torque signals, the control unit digitally analyzes PWM duty cycle values to extract torque information. This substitution maintains measurement precision while significantly improving control processing efficiency and reducing delays.
4Measurement precision
If conventional motor driving control devices use separate torque detection circuits, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies self-service by having the PWM generation unit provide torque information as a byproduct of its normal PWM signal generation function. The control unit simply reads the PWM duty cycle value that the PWM generation unit is already generating for motor control, and uses this same value for torque detection and torque hold control. This self-service approach eliminates the need for separate torque detection circuits while maintaining precise torque measurement.
Data Source
AI summary
A motor driving control device has a motor driving unit configured to supply a current to coils of a motor, and a control unit configured to control an operation of the motor driving unit in a vector control mode. The control unit includes a state signal output unit configured to output a pulse signal indicating a predetermined value corresponding to a state of the motor or a control state of the control unit among values generated in a process of calculation processing in the vector control mode.