Automatic Steering Torque Cancellation for Collision Avoidance

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Solution Overview

Problem

Existing driving assistance systems face a decrease in steering angle followability during collision avoidance control due to opposing torques from driver steering and assist torques, leading to insufficient steering angles and potential collisions or lane deviations.

Innovation Solution

A driving assistance device and method that includes a target steering torque setting unit, cancellation torque setting unit, and steering control unit to manage the steering angle of a vehicle by canceling the total driver steering torque, using a cancellation torque calculated based on the driver's steering torque, thereby enhancing steering angle followability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If driver steering torque and assist torque are applied during automatic steering, then the driver can maintain control, but the steering angle followability decreases due to opposing torques

Engineering Contradiction:
Improvesteering angle followabilityVSAvoidtotal steering torque
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The system applies preliminary anti-action by detecting driver steering torque and generating a cancellation torque in advance to counteract the opposing torque effect. The cancellation torque is calculated based on the detected driver steering torque and applied before it can significantly degrade the steering angle followability, thereby preventing the harmful effect rather than correcting it after occurrence

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system implements the counterweight principle by introducing a cancellation torque that acts in the opposite direction to the driver steering torque. This cancellation torque serves as a counterbalancing force that neutralizes the negative impact of driver input on the automatic steering control, allowing the target steering torque to effectively control the steering angle without opposition

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Reliability

If cancellation torque is applied to counteract driver steering torque, then steering angle followability increases, but the system complexity increases

Engineering Contradiction:
Improvesteering angle followabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system merges the cancellation torque function with the existing steering control system by integrating the torque detection and cancellation mechanisms into the current automatic steering architecture. The cancellation torque is combined with the target steering torque to form the total steering control torque, eliminating the need for separate independent systems and reducing overall complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system employs feedback by continuously detecting the driver steering torque and using this information to dynamically adjust the cancellation torque. The detected driver steering torque serves as feedback input that automatically generates the appropriate cancellation torque magnitude and direction, creating a closed-loop control that adapts to driver behavior without requiring complex manual intervention

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4253196A1Driving assistance device, driving assistance method, and program
Publication Date: 2023.10.04 TOYOTA JIDOSHA KK
  • EP4253196A1 patent drawingFigure 1
  • EP4253196A1 patent drawingFigure 2
  • EP4253196A1 patent drawingFigure 3

AI summary

To increase steering angle followability of automatic steering, it is provided a driving assistance device (1) for executing collision avoidance control of controlling a steering angle (θs) of an own vehicle (100) such that the own vehicle (100) travels along a target trajectory (Rt) which enables the own vehicle (100) to avoid a collision with an obstacle (OB). The driving assistance device (1) includes: a setting unit configured to set a target steering angle (θt), and to set a target steering torque (Tt) for matching the steering angle (θs) with the target steering angle (θt); a cancellation unit (17) configured to set a cancellation torque (TCA) which cancels a total steering torque (TSUM) obtained by summing a driver steering torque (Tdr) and a steering assist torque (TAS) set based on the driver steering torque (Tdr); and a control unit (60) configured to execute steering control of controlling the steering angle (θs) based on a torque control amount obtained by adding the target steering torque (Tt) to the cancellation torque (TCA).