Torque Steer Compensation via Wheel Slip Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for compensating torque steer in vehicles using power steering systems rely on indirect information, such as engine RPM and acceleration pedal manipulation, which fail to accurately recognize torque steer variations due to wheel slip, resulting in inadequate compensation.
Innovation Solution
An electronic control unit for a motor-driven power steering system calculates the actual driving torque value considering wheel slip, generates a compensation current to address torque steer, and includes a direction compensation unit to account for external factors like road gradients, ensuring precise torque steer compensation and lateral balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If indirect information (engine RPM, acceleration pedal manipulation) is used to estimate torque steer degree, then the power steering system can operate without additional sensors, but the torque steer compensation accuracy deteriorates due to inability to recognize wheel slip variations
Solution Approach 1:
The patent uses wheel speed sensors as intermediary devices to detect wheel slip conditions. These sensors measure the rotational speed of each wheel, and the control unit compares these speeds to detect slip variations. This intermediary measurement approach allows indirect observation of torque steer effects without requiring direct torque sensors, thereby maintaining device simplicity while improving measurement accuracy through the use of available wheel speed data.
2Measurement precision
If direct torque measurements considering wheel slip are used, then torque steer compensation accuracy is improved, but the device complexity and control algorithm complexity increase
Solution Approach 1:
The patent implements a feedback control mechanism where the control unit continuously monitors wheel speed sensor data, detects wheel slip conditions, and adjusts the steering assistance force accordingly. The detected torque steer degree is fed back to the control unit, which then modifies the steering motor output to compensate for the torque steer. This closed-loop feedback approach enables accurate torque steer compensation using existing sensors without requiring additional complex measurement devices.
Solution Approach 2:
The patent replaces complex mechanical torque measurement systems with an electronic control approach. Instead of using mechanical sensors to directly measure drive shaft torque, the system uses wheel speed sensors and electronic algorithms to calculate torque steer degree. This substitution of mechanical measurement with electronic sensing and computation simplifies the physical hardware while maintaining or improving measurement accuracy through software-based torque estimation.
3Device complexity
If conventional torque steer compensation is applied without considering external factors, then the control algorithm remains simple, but the compensation accuracy deteriorates due to unaccounted lateral imbalances
Solution Approach 1:
The patent implements dynamic adaptation of the torque steer compensation algorithm by continuously monitoring driving conditions and adjusting compensation parameters in real-time. The control unit modifies the compensation force based on detected wheel slip variations and steering conditions, transitioning from a static compensation approach to a dynamic one. This allows the system to adapt to changing external factors such as road gradients and lateral imbalances without requiring a completely new control algorithm or additional sensors.
Data Source
AI summary
The present invention relates to an electronic control unit and a method for compensating for a torque steer. The electronic control unit includes: a driving torque calculation unit that calculates a drive shaft driving torque value, which is a torque value transmitted from an engine to a drive shaft; a torque steer degree calculation unit that calculates the actual driving torque value of a vehicle based on the drive shaft driving torque value, and calculates a torque steer degree by using the actual driving torque value; a compensation current calculation unit that calculates a torque steer compensation current value that compensates for the torque steer using the torque steer degree; a direction compensation unit that calculates a direction compensation current value according to a travelling direction of the vehicle; and a motor driving control unit that calculates a basic control current value using a steering angle and a steering torque value, calculates the final control current value by adding the torque steer compensation current value and the direction compensation current value to the basic control current value, and generates a control current according to the final control current value in order to supply the control current value to an electric motor.