Front and Rear Torque Filtering for Pitch-Induced Wheel Slip
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Solution Overview
Problem
The phenomenon of repeated wheel slip and deterioration of wheel slip control performance in vehicles due to longitudinal load movement and the lack of real-time reflection of pitch motion characteristics and load information in existing control methods.
Innovation Solution
A method that determines the natural frequency of vehicle suspension pitch motion, uses filters to remove or enhance this frequency component in the driving force command, and adjusts the driving force applied to the front and rear wheels based on real-time vehicle driving information to prevent wheel slip and optimize traction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional TCS control methods are used to limit tire slip, then wheel slip control is attempted, but repeated wheel slip occurs due to longitudinal load movement and pitch motion not being reflected in real-time
Solution Approach 1:
The patent applies preliminary action by calculating and compensating for longitudinal load movement based on predicted pitch motion characteristics before wheel slip actually occurs. The control system proactively adjusts driving force to prevent wheel slip caused by load transfer, rather than reacting after slip is detected. This is achieved by computing expected load changes from pitch angle and acceleration data, then pre-adjusting torque commands to counteract the anticipated wheel load variations.
2Reliability
If feedback control is used to reduce driving force when wheel slip is detected, then tire slip is temporarily reduced, but pitch motion causes vertical load to decrease again and wheel slip occurs repeatedly
Solution Approach 1:
The patent implements feedback control by continuously monitoring pitch angle, pitch acceleration, and wheel speed data to dynamically adjust driving force commands. The system uses real-time feedback from suspension sensors and wheel speed sensors to compute longitudinal load movement and modify torque distribution accordingly. This closed-loop feedback mechanism ensures that control actions are continuously adapted to current vehicle dynamics, preventing repeated wheel slip while maintaining responsive control without delay.
3Productivity
If driving force is increased to improve acceleration performance, then vehicle acceleration improves, but vertical load on driving wheels decreases due to pitch motion and wheel slip occurs
Solution Approach 1:
The patent applies parameter changes by dynamically modifying driving force commands based on real-time pitch motion parameters (pitch angle, pitch acceleration) and calculated longitudinal load movement. The control system adjusts torque magnitude and distribution parameters according to suspension characteristics and current vehicle state, optimizing the balance between acceleration performance and traction control. This allows maximum acceleration force to be applied without exceeding the reduced friction limit caused by pitch-induced load transfer.
Data Source
AI summary
A method for controlling driving force of a vehicle includes determining a natural frequency of vehicle suspension pitch motion according to characteristics of a suspension device of the vehicle, providing a filter configured for removing or passing a natural frequency component of the vehicle suspension pitch motion to a control unit of the vehicle, determining, by the control unit, a required driving force command based on vehicle driving information collected during vehicle driving, determining, by the control unit, a final front wheel driving force command and a final rear wheel driving force command through a filtering process using the filter from the determined required driving force command, and controlling, by the control unit, a driving force applied to a front wheel and a rear wheel of the vehicle by a driving device for driving the vehicle according to the determined final front wheel driving force command and the determined final rear wheel driving force command.