Motor Advance Angle Correction for Accurate Tracking Position Control
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Solution Overview
Problem
Existing motor control systems face challenges in achieving accurate tracking-type position control due to response delays and disturbances, leading to deviations from target positions, especially when speed control is updated based on moving target positions.
Innovation Solution
A motor control apparatus and method that includes an encoding unit for detecting motor rotation state, a target position setting unit, and an advance angle control unit to calculate and correct the advance angle based on actual and target position deviations, using a feedback mechanism to adjust the motor's rotation speed and position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If speed control is performed by updating the target advance angle in accordance with the moving speed of the target position, then the motor can respond to speed changes, but position deviation occurs due to response delay and disturbance
Solution Approach 1:
The patent implements a dual-loop feedback control system: an inner current control loop that rapidly responds to torque demands, and an outer position control loop that ensures accurate tracking. The current control loop uses feedback from actual current measurements to adjust voltage output, while the position control loop uses feedback from position sensors to correct tracking errors. This hierarchical feedback structure allows the system to achieve both fast response and high position accuracy simultaneously.
Solution Approach 2:
The patent applies feedforward control by pre-calculating the required torque based on the desired trajectory and system dynamics. The torque command is generated in advance considering the target position, velocity, and acceleration, allowing the system to proactively compensate for inertial effects and external disturbances before they cause position deviations. This preliminary action reduces reliance on reactive feedback alone.
2Speed
If fixed-type position control is used to quickly move to a target position, then response speed is improved, but stable following performance cannot be obtained in tracking-type position control
Solution Approach 1:
The patent implements dynamic control by continuously adapting control parameters based on real-time system state. The controller adjusts torque commands dynamically according to the current position, velocity, and acceleration to match the desired trajectory. This dynamic adjustment allows the system to maintain stable following performance during tracking while achieving fast response during transient movements, effectively bridging the gap between fixed-position control and continuous tracking control.
3Use of energy by moving object
If the advance angle is controlled to optimize motor efficiency, then energy consumption is reduced, but position control accuracy deteriorates due to response delay
Solution Approach 1:
The patent optimizes the advance angle as a controllable parameter to improve motor efficiency while maintaining position accuracy. By dynamically adjusting the advance angle based on operating conditions (such as speed and load), the system operates the motor in its most efficient region without sacrificing control performance. The current control loop compensates for any efficiency-related response delays, ensuring that position accuracy is maintained even when operating at optimal energy efficiency points.
Data Source
AI summary
A motor control apparatus comprises an encoding unit configured to detect a rotation state of a motor and convert the rotation state into actual position information, a target position setting unit configured to generate a target position counter value serving as a movement target of a driven member connected to the motor, and an advance angle control unit configured to control a rotation speed of the motor based on a target advance angle, wherein the advance angle control unit comprises a target speed calculation unit configured to calculate a target speed that is an amount of change of the target position counter value, a target advance angle calculation unit configured to calculate the target advance angle corresponding to the target speed based on correspondence information between the rotation speed and the advance angle, a target advance angle corresponding to the target speed, a position deviation correction amount calculation unit configured to calculate a position deviation correction amount from a deviation amount between the actual position information and the target position counter value, and an advance angle correction amount calculation unit configured to convert the position deviation correction amount into a speed deviation correction amount and calculate, from the correspondence information between rotation speed and advance angle, an advance angle correction amount corresponding to the speed deviation correction amount, wherein position control of the driven member is performed using the target advance angle corrected by the advance angle correction amount.