Steering Holding Determination Using Kalman Filter Variance

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Solution Overview

Problem

Current steering control devices face challenges in accurately determining whether a driver is holding the steering member, which affects the switching between manual and automatic driving modes.

Innovation Solution

A steering holding determination device that calculates predicted values of state quantities related to steering and wheel turning, using a variance analysis to determine if the driver is holding the steering member, incorporating a Kalman filter for state estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional steering control devices use basic torque and inertia calculations to determine steering holding state, then the device complexity is low, but the measurement precision of driver holding state is insufficient

Engineering Contradiction:
Improveaccuracy of determining steering holding stateVSAvoidcomplexity of determination device
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex additional sensors with a computational approach using a Kalman filter algorithm. The system substitutes physical measurement devices with a mathematical model that processes existing sensor data (steering angle, steering torque, wheel acceleration) to estimate driver holding state, thereby achieving high measurement precision without increasing hardware complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a Kalman filter as an intermediary computational layer between the physical sensors and the steering control system. This intermediary processes raw sensor data through prediction and update steps, extracting meaningful information about driver holding state from noisy measurements without requiring direct physical contact or additional sensors

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If additional sensors are added to improve steering holding detection accuracy, then the measurement precision improves, but the device complexity and cost increase

Engineering Contradiction:
Improveaccuracy of detecting steering holding stateVSAvoidnumber of sensors and system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent enables the existing steering system to self-diagnose driver holding state using its own operational data. The Kalman filter utilizes steering angle, steering torque, and wheel acceleration data already generated during normal operation to determine whether the driver is holding the steering wheel, eliminating the need for external detection sensors

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent makes existing sensors serve multiple functions: steering angle sensors provide both steering control data and driver holding detection data; steering torque sensors provide both assist control information and driver input detection; wheel acceleration sensors provide both stability control data and holding state verification. This multi-functionality achieves high detection accuracy without adding dedicated sensors

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS12168486B2Steering holding determination device, steering control device, and steering device
Publication Date: 2024.12.17 ASTEMO LTD
  • US12168486B2 patent drawing
  • US12168486B2 patent drawing
  • US12168486B2 patent drawing

AI summary

A steering holding determination device configured to determine whether a driver holds a steering member, the steering holding determination device including: a predicted value calculation unit configured to calculate a predicted value of at least one of one or more state quantities related to steering of the steering member and one or more state quantities related to turning of a wheel; and a steering holding determination unit configured to determine whether the driver holds the steering member with reference to the predicted value calculated by the predicted value calculation unit and a variance of the predicted value.