Hybrid Vehicle Torque Control with Staggered Zero-Cross Timing
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Solution Overview
Problem
Existing vehicle control systems face challenges in efficiently reducing noises and vibrations caused by gear contact during torque changes in hybrid vehicles, as the timing of zero-cross processes for front and rear wheels is often synchronized, leading to simultaneous noise and vibration occurrences.
Innovation Solution
A vehicle control device with separate drive units for front and rear wheels, utilizing a control unit that calculates and adjusts the target torques and change rates to operate zero-cross processes at different timings, ensuring the first drive torque reaches zero at a slower rate than the second drive torque, thereby reducing overall noise and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the control device operates zero-cross processes for front-wheel torque and rear-wheel torque at substantially the same timing, then the torque change is controlled efficiently, but noises and vibrations occur simultaneously causing increased disturbance
Solution Approach 1:
The control device implements periodic zero-cross processes for front-wheel and rear-wheel torque at different timings. The first zero-cross process is executed for either front-wheel or rear-wheel torque, followed by a second zero-cross process for the other wheel's torque after a predetermined time has elapsed. This periodic, staggered execution prevents simultaneous noise and vibration occurrences while maintaining efficient torque change control.
2Speed
If the zero-cross processes for front and rear wheels are executed simultaneously, then the control response is fast, but the contact noises of gears occur at the same time increasing overall noise
Solution Approach 1:
The control device executes the first zero-cross process for one wheel's torque before executing the second zero-cross process for the other wheel's torque. By performing the zero-cross process for the first wheel in advance and then executing it for the second wheel after a predetermined time, the control device prevents simultaneous gear contact noises while maintaining fast overall control response.
3Object-affected harmful factors
If the change rate of drive torque is reduced to minimize noise, then noises and vibrations are reduced, but the time required for torque to reach the target value increases
Solution Approach 1:
The control device segments the zero-cross process into two separate executions: a first zero-cross process for one wheel's torque and a second zero-cross process for the other wheel's torque. By dividing the torque change into sequential segments rather than simultaneous execution, the device reduces noise and vibrations during each segment while maintaining acceptable overall response time through efficient sequential processing.
Data Source
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AI summary
A vehicle control device (500) includes a control unit (100) configured to obtain information relating to a drive state of a vehicle(1), calculate a requirement torque (TQ), compute a first target torque (TQx), a second target torque (TQy), and an ideal change rate (z10, z11, z12, z20, z25, z30, z40, z50, z60, z70, z80) of a total torque (Tqz) of a first drive torque (Tqx, Tqx1) and a second drive torque (Tqy, Tqy1), and at least control a magnitudes of the first drive torque (Tqx, Tqx1) and the second drive torque (Tqy, Tqy1) outputted from the first drive unit (10) and the second drive units (20). The control unit (100) is configured to control the first drive unit (10) to operate a first zero-cross process and control the second drive unit (20) to operate a second zero-cross process after the first zero-cross process ends.