Shared Timer Motor Control for PWM-Angle Mode Arbitration
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Solution Overview
Problem
Existing motor control devices require a dedicated microcomputer with an angle timer to switch between PWM control and angle synchronous control, leading to increased complexity and cost, and potential interference between control modes causing motor instability and torque fluctuations.
Innovation Solution
A motor control device with a timer circuit, control mode setting unit, PWM control unit, and angle synchronization control unit that uses compare registers and counters to manage on/off timings for switching elements, allowing mode switching without a microcomputer with an angle timer, and arbitrating control periods to prevent interference between PWM and angle synchronization control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a dedicated microcomputer with an angle timer is used to switch between PWM control and angle synchronous control, then control mode switching capability is improved, but device complexity and cost increase
Solution Approach 1:
The timer circuit is designed to serve multiple functions: it can operate as a PWM timer for PWM control mode and as an angle timer for angle synchronous control mode. By configuring the same timer circuit with different compare registers (first compare register for PWM, second compare register for angle control), the system achieves multi-functionality without requiring separate dedicated microcomputers for each control mode, thereby reducing device complexity and cost while maintaining control mode switching capability
Solution Approach 2:
The patent merges the PWM control function and angle synchronous control function into a single integrated control system using one timer circuit. The timer circuit simultaneously supports both control modes by switching between different compare registers, eliminating the need for separate dedicated microcomputers and reducing overall system complexity
2Speed
If PWM control and angle synchronous control are executed simultaneously without arbitration, then control responsiveness is improved, but motor stability deteriorates due to control interference
Solution Approach 1:
The system establishes a control mode arbitration mechanism that determines in advance which control mode (PWM or angle synchronous) should be executed based on predetermined criteria. This preliminary arbitration prevents simultaneous execution of both control modes, eliminating control interference and maintaining motor stability while still allowing rapid switching between modes for responsive control
Solution Approach 2:
The control mode arbitration unit acts as an intermediary between the PWM control unit and the angle synchronous control unit. It mediates the execution of these two control modes by selecting which one should run at any given time, preventing direct interference between them while maintaining overall control responsiveness through rapid mode switching
Data Source
AI summary
A motor control device includes a timer circuit, a control mode setting unit, a PWM control unit, an angle calculation unit, and an angle synchronization control unit. The PWM control unit switches the operation mode of the angle synchronization control unit according to the control mode set by the control mode setting unit, and executes the PWM control when the operation mode of the angle synchronization control unit is the PWM mode. The angle synchronization control unit executes the angle synchronization control when the operation mode is the angle synchronization mode.