Vehicle Vibration Damping Control via Slip-Corrected Wheel Torque Estimation
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Solution Overview
Problem
Existing vibration damping control devices for vehicles face challenges in accurately estimating wheel torque, especially when wheels slip or reverse travel, leading to inadequate vibration suppression and potential vibration amplification due to incorrect torque direction and magnitude assumptions.
Innovation Solution
A wheel torque estimating device that corrects estimated wheel torque values based on slip state quantities and directional changes, using wheel speed sensors without direct torque measurement, to improve accuracy and effectiveness in vibration damping control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If wheel torque is estimated based on wheel speed during wheel slip or reverse travel, then the estimation becomes inaccurate or erroneous, but installing direct torque sensors increases device complexity and cost
Solution Approach 1:
The system changes the parameters used for torque estimation based on detected wheel conditions. When wheel slip or reverse travel is detected, the system switches from using wheel speed-based estimation to alternative parameters such as vehicle acceleration and engine torque, thereby maintaining estimation accuracy without requiring direct torque sensors
Solution Approach 2:
The control device acts as an intermediary that processes multiple input parameters (wheel speed, vehicle acceleration, engine torque) and synthesizes a corrected wheel torque estimate. This intermediary processing layer compensates for the inadequacies of direct wheel speed-based estimation during slip and reverse travel conditions
2Reliability
If wheel torque estimated value is used without correction during reverse travel, then the torque direction becomes erroneous, but implementing correction logic increases control system complexity
Solution Approach 1:
The control system dynamically adjusts the torque estimation based on the current operating condition. When reverse travel is detected, the system automatically corrects the torque direction by reversing the sign of the estimated torque value, ensuring accurate control without requiring separate hardware for different travel directions
Solution Approach 2:
The system performs preliminary detection of reverse travel conditions and pre-corrects the torque estimation before it is used in control calculations. This preliminary correction action prevents erroneous torque application and eliminates the need for complex real-time direction judgment during control execution
3Measurement precision
If wheel torque estimation is performed without considering slip state, then the estimation accuracy deteriorates during slip conditions, but adding slip detection and correction increases processing complexity
Solution Approach 1:
The system implements feedback by continuously monitoring wheel slip conditions and using this information to correct the torque estimation. The detected wheel slip state feeds back into the torque calculation process, allowing the system to adaptively adjust the estimation accuracy based on current traction conditions without requiring complex external sensors
Data Source
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AI summary
There is provided a vibration damping control device which suppresses pitching and bouncing vibration of a vehicle through a drive output control based on a wheel torque estimated value estimated with a wheel speed, etc., which device uses the estimated value of a wheel torque while taking into account conditions where no good estimation of the wheel torque is executable. The vibration damping control device comprises a wheel torque estimated value acquisition portion which acquires a wheel torque estimated value; and a driving torque control portion which controls a driving torque of the vehicle to suppress pitching or bouncing vibrational amplitudes based on the wheel torque estimated value, wherein the absolute value or the sign of the wheel torque estimated value is corrected in accordance with the degree of a slip of the wheel or the direction of movement of the vehicle. Further, there is provided a torque estimating device suitable for a vibration damping control and other running, motional or braking-driving force controls for a vehicle, etc.