Vehicle Steering Force Correction for Driver Override

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Solution Overview

Problem

Existing vehicle driving support devices experience discomfort due to varying steering reaction forces depending on operation direction during automatic steering, leading to reduced driver operability and increased steering force loss.

Innovation Solution

A driving support device with an assist control unit, tracking control unit, intervention detecting unit, tracking limiting unit, and steering force correcting unit that generates assist torque and automatic steering torque, limiting the tracking process to allow driver intervention and correcting steering forces to maintain a neutral steering point, thereby reducing reaction force differences and improving operability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If the tracking process is executed to generate automatic steering torque, then the vehicle can be steered automatically along the target trajectory, but the steering reaction force varies depending on operation direction causing driver discomfort

Engineering Contradiction:

Improveautomatic steering capabilityVSAvoidsteering operation comfort

Core Design Contradiction:

Extent of automationVSEase of operation

Solution Approach 1:

The system performs preliminary detection of driver intervention intent before the actual steering operation occurs. By monitoring steering torque and angular velocity, the system anticipates driver override and preemptively adjusts the tracking process gain, ensuring smooth transition and consistent steering reaction force from the outset of driver intervention

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the tracking process gain based on detected driver intervention conditions. When driver override is detected, the gain is reduced to allow driver steering input to dominate, while maintaining automatic tracking functionality when no intervention is detected, creating a dynamic balance between automation and driver control

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the tracking process is regulated to allow driver override steering operation, then the driver can steer the vehicle, but steering force loss occurs when returning the steering wheel to center

Engineering Contradiction:

Improvedriver override capabilityVSAvoidsteering force loss

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The system continuously monitors steering angular velocity and torque to detect driver intervention in real-time. This feedback mechanism triggers automatic adjustment of the tracking process gain, creating a closed-loop control system that responds to driver input by reducing automatic steering torque, thereby preventing steering force loss during steering wheel return

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the gain parameter of the tracking process based on detected steering angular velocity thresholds. When the threshold is exceeded indicating driver override, the gain is reduced to minimize automatic steering torque contribution, preventing energy loss while maintaining driver override capability

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the tracking process cancels steering angle deviation during driver override, then the vehicle returns to target trajectory, but the driver cannot steer the vehicle effectively

Engineering Contradiction:

Improvetrajectory tracking accuracyVSAvoiddriver steering effectiveness

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system dynamically adjusts the tracking process gain based on real-time detection of driver intervention. When driver override is detected through steering torque and angular velocity monitoring, the gain is reduced to prioritize driver steering effectiveness, while maintaining high gain for trajectory accuracy during normal automatic operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system maintains continuous trajectory tracking functionality while adapting its contribution level. The tracking process continues to operate and calculate target steering angles, but its torque contribution is modulated based on driver intervention detection, ensuring both trajectory accuracy and driver steering effectiveness are maintained continuously

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS10501115B2Driving support device for vehicle and vehicle driving support method

Publication Date: 2019.12.10 DENSO CORP

AI summary

A driving support device for a vehicle includes an assist control unit for generating an assist command for generating an assist torque, a tracking control unit for generating a tracking command for generating an automatic steering torque, an intervention detection unit for detecting an intervention in a tracking process by a steering operation, a tracking limiting unit that limits the tracking process during a detection of the intervention, a steering force correcting unit for generating a correction command for reducing a difference in steering reaction force caused by an operation direction of a driver during the detection of the intervention and a motor driving unit for driving the motor based on the assist command, the tracking command and the correction command.