Motor Control Torque Sign Constraint for Gear Noise Reduction
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Solution Overview
Problem
Disturbances such as irregular road surfaces cause fluctuations in the third target torque value, potentially reversing the positive or negative sign of the torque command value, leading to anomalous sounds from gears and other components in motor systems.
Innovation Solution
A motor controlling apparatus that applies the same sign to the first target torque value and the torque command value, and limits the torque command value according to the first target torque value to prevent sign reversal and minimize anomalous sounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the torque command value is calculated based on filtered rotational speed and torque values, then the control response is improved, but disturbances cause fluctuations that may reverse the sign of the torque command value
Solution Approach 1:
The patent applies preliminary action by pre-determining the sign of the torque command value based on the sign of the first target torque value before final torque calculation. This ensures that even when disturbances cause fluctuations in the calculated torque, the sign remains consistent with the original control intent, preventing gear contact direction reversals.
2Adaptability or versatility
If the torque command value fluctuates due to road surface irregularities, then the system adapts to disturbances, but the positive or negative sign may be reversed causing anomalous sounds
Solution Approach 1:
The patent applies preliminary anti-action by counteracting the potential harm of sign reversal before it occurs. By constraining the torque command value to maintain the same sign as the first target torque value, the system prevents the harmful effect of gear contact direction reversal and associated anomalous sounds before they can manifest.
3Reliability
If the torque command value is constrained to maintain the same sign as the first target torque value, then sign reversal is prevented, but the torque response may become less adaptive to disturbances
Solution Approach 1:
The patent applies local quality by applying different treatment to different aspects of the torque command value. The magnitude of the torque is allowed to fluctuate and adapt to disturbances, while only the sign is constrained to maintain consistency. This selective approach preserves adaptability in torque magnitude while ensuring reliability in torque direction.
Data Source
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AI summary
A motor controlling apparatus including a first target torque value calculator (2), a frequency detector (6), a second target torque value calculator (12), a torque command value calculator (3), a torque limiter (13), and a controller (4). The first target torque value calculator (2) calculates a first target torque value, which is a target value of an output torque of a motor (5), based on vehicle information. The frequency detector (6) detects a motor rotational frequency. The second target torque value calculator (12) calculates a second target torque value based on the rotational frequency. The torque command value calculator (3) mathematically combines (e.g., adds) the first and target torque values to calculate a torque command value. The torque limiter (13) sets the signs of the first target torque value and the torque command value to be equal to limit the torque command value according to the first target torque value. The controller (4) controls the motor (5) based on the limited torque command value.