Vehicle Torque Control via Gear-Ratio-Limited Vibration Suppression
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Solution Overview
Problem
Existing driving force control devices for vehicles face limitations in effectively suppressing sprung vibration damping control performance, particularly in vehicles with small torque capacity drive devices, where setting upper and lower limit values for vibration suppression torque restricts the ability to fully exert damping control.
Innovation Solution
A driving force control device that calculates and adjusts vibration suppression torque based on the current gear ratio of the transmission, allowing the upper and lower limit values to increase with gear ratio, thereby relaxing the restriction on vibration suppression torque and enhancing damping control performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If upper and lower limit values are set for vibration suppression torque, then basic control for the engine is maintained, but sprung vibration damping control performance cannot be sufficiently exerted
Solution Approach 1:
The patent applies dynamics by making the upper and lower limit values of vibration suppression torque variable rather than fixed. The limit values are dynamically adjusted based on the gear ratio, allowing the system to adapt to different operating conditions. When the gear ratio is high (low speed gear), the limit values are increased to allow greater vibration suppression torque, while when the gear ratio is low (high speed gear), the limit values are decreased to maintain engine basic control
Solution Approach 2:
The patent changes the parameter of limit values for vibration suppression torque based on the gear ratio. By multiplying the base limit values by the gear ratio, the system adjusts the allowable vibration suppression torque range dynamically. This parameter change allows the system to exert sufficient damping control performance in low speed gears while maintaining engine stability in high speed gears
2Productivity
If the ratio of vibration suppression torque to driving torque is increased in small displacement engines, then sprung vibration suppression is enhanced, but throttle opening degree change adversely affects basic engine control
Solution Approach 1:
The system dynamically adjusts the allowable vibration suppression torque based on gear ratio, recognizing that the same vibration suppression torque has different impacts on engine control depending on the operating gear. In low speed gears with high gear ratios, larger torque variations are acceptable, while in high speed gears, smaller variations are maintained to protect basic engine control
Solution Approach 2:
The patent applies local quality by treating different gear ranges differently. Instead of using a uniform limit for vibration suppression torque across all gears, the system applies gear-specific limit values. This allows aggressive vibration suppression in low speed gears where it is more effective, while maintaining conservative limits in high speed gears where engine stability is more critical
Data Source
AI summary
A vibration suppression torque calculation means calculates a vibration suppression torque for suppressing a sprung vibration. An upper/lower limit value setting means is configured to set, based on a gear ratio of a transmission, upper and lower limit values whose absolute values are increased as the gear ratio is increased. An upper/lower limit restriction means calculates a final vibration suppression torque acquired by using the upper and lower limit values to impose upper/lower limit restriction on the vibration suppression torque. An addition unit sets a value acquired by adding the final vibration suppression torque to a driver required torque to a target torque.