Electronic Control Device Steering Vibration Suppression
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Solution Overview
Problem
Existing electronic power steering systems face challenges in simultaneously improving steering responsiveness and preventing steering wheel vibration, particularly when the steering wheel is steered, due to variations in steering torque caused by engine vibrations, driver input, power supply noise, and other factors.
Innovation Solution
An electronic control device is implemented that includes a torque current control unit, a differential control unit, and a command value calculation unit to adjust motor current command values based on steering torque and rotation speed, correcting for noise and torque variations to minimize steering wheel vibrations while enhancing responsiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a smoothing filter is used to smooth quantization errors, then steering wheel vibration is reduced, but steering responsiveness deteriorates
Solution Approach 1:
The patent applies dynamics by making the correction value adaptive rather than fixed. The correction value is calculated dynamically based on the differential value of steering torque and the current steering torque, allowing the system to respond differently to actual steering inputs versus noise-induced variations. This dynamic adjustment resolves the contradiction by enabling vibration suppression without sacrificing responsiveness to genuine steering actions.
Solution Approach 2:
The patent changes parameters by introducing a differential-based correction mechanism that modifies the current command value based on the rate of change of steering torque. By using the differential value (change in torque over time) as a basis for correction, the system can distinguish between rapid changes caused by driver input and slower variations caused by noise, thereby maintaining responsiveness while reducing vibration.
2Speed
If correction based on torque differential value is applied, then steering responsiveness is improved, but steering wheel vibration increases
Solution Approach 1:
The patent implements feedback by continuously monitoring both the steering torque and its differential value, then using this information to adjust the correction applied to the current command. The feedback loop compares the differential-based correction with the actual torque state, allowing the system to amplify genuine steering signals while suppressing noise-induced vibrations through iterative adjustment.
Solution Approach 2:
The patent applies partial action by using the differential value only as a component of the correction, not as the sole determinant. The correction value is derived from a combination of the differential value and the current torque state, applying correction partially based on rate of change and partially based on absolute torque level, thereby achieving responsiveness without excessive vibration amplification.
Data Source
AI summary
An electronic control device controls an electronic power steering apparatus including a motor configured to assist steering of a steering wheel provided in a vehicle and a torque sensor configured to detect a steering torque applied to the steering wheel. The electronic control device includes: a torque current control unit that sets a first current command value to be supplied to the motor according to a value of the steering torque applied to the steering wheel; a differential control unit that calculates a torque differential value as a differential value of the steering torque and sets a second current command value according to the torque differential value and a rotation speed of the motor; and a command value calculation unit that calculates a motor current command value to be supplied to the motor based on the first current command value and the second current command value.