Hybrid Vehicle Torque Control Device for Vibration Suppression
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Solution Overview
Problem
Existing control devices for hybrid vehicles face challenges in sufficiently suppressing torque pulsation components due to changes in transmission characteristics over time and environmental conditions, leading to unintended vehicle vibrations and noise.
Innovation Solution
A control device that computes compensation torque to reduce engine torque pulsation and adjusts the torque command value for the electric motor, ensuring it does not command a value opposite in sign to the average torque command when it is smaller than the amplitude, and controls the phase of the compensation torque to minimize fluctuations in the driving shaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compensation torque is computed using a torque transmission function from driving source to driving shaft, then torque pulsation component can be reduced, but suppression effectiveness deteriorates when transmission characteristics change due to secular change and environment
Solution Approach 1:
The patent implements feedback by detecting the actual torque command value for the electric motor and using it to compute the compensation torque. The electronic control unit continuously monitors the torque command value and adjusts the compensation torque based on the detected actual value, creating a closed-loop control system that adapts to changing transmission characteristics without requiring recalibration of the torque transmission function.
Solution Approach 2:
The system uses its own operational data (the torque command value it generates) to compute the compensation torque. By leveraging the detected actual torque command value from its own control operations, the system eliminates the need for external calibration data or predetermined transmission characteristics, making it self-sufficient and robust to environmental changes.
2Object-affected harmful factors
If torque command value combines required torque and compensation torque, then engine torque pulsation is reduced, but polarity change of motor torque generates noise
Solution Approach 1:
The patent applies preliminary anti-action by computing the compensation torque in advance to counteract the engine torque pulsation. The electronic control unit calculates the compensation torque based on the detected torque command value and applies it to the electric motor before the pulsation effect occurs, thereby preventing the harmful vibration and noise from manifesting.
Solution Approach 2:
The system dynamically adjusts the torque command value for the electric motor by continuously combining the required torque with the computed compensation torque. This dynamic adjustment allows the system to respond to changing operating conditions while maintaining suppression of engine torque pulsation effects.
3Object-affected harmful factors
If torque command value is corrected to prevent opposite sign values, then unintended vehicle vibrations are prevented, but control complexity increases
Solution Approach 1:
The patent applies inversion by correcting the torque command value in the opposite direction when it would otherwise become opposite in sign to the average torque command value. The electronic control unit detects when the torque command value would cause unintended vibrations and applies a corrective adjustment in the opposite direction, thereby preventing the harmful effect through a straightforward inverse operation.
Data Source
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AI summary
An electronic control unit is mounted on a vehicle including an internal combustion engine and electric motors, each of which is connected to a driving shaft to be capable of transmitting power. The electronic control unit is configured to compute compensation torque reducing a pulsation component of engine torque of the internal combustion engine and command a value in which required torque of the electric motor is combined with the computed compensation torque to the electric motor as a torque command value of the electric motor. The electronic control unit is configured to correct the torque command value so that the value opposite in sign to an average torque command value is not commanded to the electric motor when the average torque command value is smaller than an amplitude of the torque command value.