Steer-by-Wire Active Inertia Feedback for Steering Feel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Steer-by-wire steering systems in vehicles lack full replication of inertial forces, leading to incomplete steering feel and restricted high accelerations due to missing mechanical connections, which affects the driving experience.
Innovation Solution
A method to control steer-by-wire systems by actively controlling inertia feedback using a controller that calculates and applies an output torque to mimic conventional steering inertia, adapting to vehicle type and speed, and integrating it with a feedback actuator to replicate the steering feel of conventional systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a steer-by-wire steering system is used to eliminate mechanical linkage between steering wheel and road wheels, then steering precision and control accuracy are improved, but steering feel and inertial feedback are deteriorated
Solution Approach 1:
The patent replaces the mechanical linkage between steering wheel and road wheels with an electronic control system. Sensors detect steering wheel position and road wheel position, and a controller calculates and actuates road wheel positioning without mechanical connection, achieving precise steering control while eliminating mechanical inertia feedback.
Solution Approach 2:
The patent implements a feedback mechanism where sensors continuously monitor steering wheel angle and road wheel angle, and the controller uses this feedback information to adjust the actuator's position commands, ensuring accurate steering response despite the lack of mechanical coupling.
2Reliability
If mechanical linkage between steering wheel and steering gear is eliminated, then steering system reliability and maintenance are improved, but inertial force feedback to driver is reduced
Solution Approach 1:
The patent substitutes the mechanical power steering system with an electric actuator system. The actuator receives control signals from the controller and directly positions the road wheels, eliminating mechanical linkages and their associated inertia while maintaining reliable steering control through electronic feedback loops.
Solution Approach 2:
The patent introduces sensors and a controller as intermediaries between the driver's steering input and the road wheel positioning. These intermediaries translate mechanical steering wheel motion into electronic control signals that actuate the road wheels, providing reliable control without direct mechanical coupling.
3Ease of operation
If conventional power steering system is used with mechanical connection, then inertial steering feel is naturally provided, but steering system complexity and energy consumption increase
Solution Approach 1:
The patent extracts the power steering function from the mechanical linkage and places it in a separate electric actuator system. This separation allows the mechanical steering wheel to remain simple while the actuator provides controlled assistance, reducing overall system complexity and energy consumption compared to conventional mechanical power steering.
Solution Approach 2:
The patent replaces the mechanical power steering gear with an electric actuator system controlled by sensors and a controller. This substitution eliminates complex mechanical components while providing precise steering control and optional inertial feedback through electronic means.
Data Source
AI summary
A method to control a steer-by-wire steering system for a vehicle including a steering wheel, a road wheel actuator to actuate wheels, and a feedback actuator to apply a feedback torque to the steering wheel, includes providing steering wheel angular acceleration, steering wheel angular speed and vehicle speed to a controller, deciding based on the steering wheel angular acceleration whether the steering wheel is accelerating in or decelerating against a turning direction, and calculating a steering wheel torque with a tuning map by the controller, calculating a vehicle speed gain with a vehicle speed tuning map applied to the vehicle speed by the controller, deciding whether the steering wheel turns clockwise or counterclockwise based on the steering wheel angular speed by the controller, calculating an output torque counteracting the acceleration of the steering wheel based on results of the previous steps, and sending the output torque to the feedback actuator.