Adaptive Curve Speed Control Using Map Database and Operator Preferences

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Solution Overview

Problem

Conventional curve speed control systems are inflexible and unable to accommodate operator preferences or vehicle characteristics, leading to excessive braking and steering efforts, especially on insufficient friction surfaces, and fail to handle instantaneous changes in curvature radius, resulting in accidents.

Innovation Solution

A smart curve speed control system that uses a map database and locator device to determine vehicle location and allowable speed, adjusting speed based on operator preferences and vehicle characteristics, with continuous feedback for optimal acceleration and deceleration control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional rigid one-size-fits-all curve speed control systems are used, then the system structure is simple, but the system cannot accommodate operator preferences or vehicle characteristics, leading to excessive braking and steering efforts

Engineering Contradiction:

Improveadaptability to operator preferences and vehicle characteristicsVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system dynamically adjusts the desired curve speed profile by incorporating operator preference factors and vehicle characteristic factors, transforming a static rigid control system into a dynamic adaptive one that modifies speed commands based on real-time conditions and user preferences

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes multiple parameters including desired curve speed profile, operator preference factors, vehicle characteristic factors, and friction coefficient estimates to achieve adaptive curve speed control that accommodates different operators and vehicle conditions

Inventive Principle:

Principle #35Parameter changes

2Reliability

If conventional systems decelerate to a fixed stable speed at curve entry, then the basic curve management is achieved, but the system does not accommodate instantaneous change in curvature radius, resulting in errors or rapid acceleration when exiting

Engineering Contradiction:

Improvecurve management safetyVSAvoidsmoothness of speed transition

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system performs preliminary deceleration before curve entry to achieve the desired curve speed profile, and then maintains this speed through the curve, eliminating the need for corrective braking or acceleration during curve execution

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the friction coefficient estimator and curve geometry data to continuously adjust the desired speed profile, ensuring smooth transitions and accurate speed control throughout the curve including exit portions with changing curvature

Inventive Principle:

Principle #23Feedback

3Speed

If operator applies excessive braking to reduce speed on curve, then the vehicle speed is reduced, but the steering effort increases and accident risk increases

Engineering Contradiction:

Improvevehicle speed reductionVSAvoidsteering effort and accident risk

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The system performs the speed reduction action before the vehicle enters the curve by calculating the desired curve speed profile in advance and commanding deceleration at the optimal time, so that the vehicle reaches the curve at the appropriate speed without requiring additional braking during curve traversal

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system automatically manages the speed control without requiring operator intervention, eliminating the harmful cycle of excessive braking and corrective steering by providing autonomous curve speed management

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS7400963B2Speed control method for vehicle approaching and traveling on a curve

Publication Date: 2008.07.15 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A vehicle curve speed control system (10) adapted for use with a vehicle (12) having an operator (14), includes a map database (16) representing a current vehicle path, and a locator device (20) communicatively coupled to the database (16) and configured to determine the location of the vehicle (12) on the path. The system (10) further includes a controller (36) configured to identify approaching curve points of a curve (18a) in terms of curvature or radius, and determine a desired speed profile based on operator preference and/or vehicle characteristic input. An acceleration profile is determined, based on the current vehicle speed, and desired speed profile. An acceleration/deceleration command at the present control loop is modified towards achieving an optimal curve speed, and is delivered to either a brake or acceleration module (40,42) to automatically accelerate or decelerate the vehicle (12) accordingly.