Handwheel Return Velocity Control via Dynamic Torque Blending

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Solution Overview

Problem

Existing vehicle steering systems face challenges in controlling the handwheel return to center velocity, leading to inconsistent steering feel and difficulty in tuning due to changes in operating conditions and friction levels.

Innovation Solution

A method and system for handwheel return to center control, which involves receiving vehicle velocity, handwheel position, handwheel velocity, and driver-applied torque values. The system determines desired and final velocity values, calculates control and blend commands using proportional integral control and static return values, and selectively controls the handwheel return to center based on these commands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional steering systems are used, then the system structure is simple, but the handwheel return to center velocity is inconsistent and difficult to tune

Engineering Contradiction:

Improvehandwheel return to center velocity controlVSAvoidcontrol system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic control of handwheel return to center velocity by adjusting the control velocity blend value based on real-time driver torque input. The system transitions from static friction-based return to dynamic velocity-controlled return, allowing the handwheel to return at different speeds depending on driving conditions and driver intent.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the torque sensor to continuously monitor driver input and adjust the return to center velocity accordingly. The control velocity blend value is calculated based on the magnitude of driver torque, creating a closed-loop control system that adapts to changing operating conditions and maintains consistent steering feel.

Inventive Principle:

Principle #23Feedback

2Reliability

If friction levels change in the steering system, then the system is simpler to manufacture, but the handwheel return to center behavior becomes inconsistent

Engineering Contradiction:

Improvehandwheel return to center consistencyVSAvoidsystem tuning difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the control parameter from static friction-based return to dynamic velocity-based return. By using the control velocity blend value that varies with driver torque magnitude, the system compensates for friction level changes and maintains consistent return behavior across different operating conditions without requiring complex manual tuning.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system replaces the traditional mechanical friction-based return mechanism with an electronic control system that uses motor torque to control handwheel velocity. This substitution eliminates the inconsistency caused by varying friction levels and allows for more reliable and tunable return behavior.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Speed

If the handwheel returns too quickly to center, then the steering response is faster, but the steering feel becomes inconsistent and uncomfortable

Engineering Contradiction:

Improvehandwheel return speedVSAvoidsteering feel consistency

Core Design Contradiction:

SpeedVSEase of operation

Solution Approach 1:

The system dynamically adjusts handwheel return speed based on driver torque input. When the driver applies small torque, the handwheel returns quickly for responsive steering. When larger torque is applied, the return speed is reduced to maintain comfort and consistency, creating a dynamic balance between speed and comfort.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The control velocity blend value serves as a dynamic parameter that changes with driver input magnitude. This allows the system to optimize return speed for each operating condition, ensuring fast response when needed while maintaining comfortable and consistent steering feel during normal operation.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250115290A1Systems and methods for controlling handwheel return to center velocity

Publication Date: 2025.04.10 STEERING SOLUTIONS IP HOLDING CORP

AI summary

An apparatus for handwheel return to center control is configured to determine a desired velocity value based on a vehicle velocity value and a handwheel position value; determine a control velocity blend value based on the vehicle velocity value and a driver applied handwheel torque value; determine a final desired velocity value based on the desired velocity value and the control velocity blend value; determine a proportional integral control value based on the control velocity blend value and an error value associated with the final desired velocity value; determine a static return command value based on the handwheel position value and the vehicle velocity value; determine a blend command value based on the proportional integral control value and the static return command value; and selectively control a return to center of the handwheel of the vehicle based on the blend command value.