Brake Steering Controller for Agricultural Tractor Tight Turns

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Solution Overview

Problem

Existing agricultural tractors face challenges in executing tight headland turns without damaging the terrain, and their braking systems pose safety risks, especially at higher speeds, due to the need for skilled operator intervention and potential for accidents during on-road use.

Innovation Solution

A vehicle braking system that uses a controller to generate brake commands based on steering angle and vehicle speed signals, along with slip estimation, to achieve braked steering without locking the driven members, allowing for automatic and safe tight turns by controlling the braking effort to limit slip, thereby eliminating headland damage and enhancing safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If independent braking of rear wheels is used to achieve tight headland turns, then turn radius is reduced, but headland damage occurs due to wheel locking and soil compaction

Engineering Contradiction:
Improveturn radiusVSAvoidheadland damage
Core Design Contradiction:
Length of moving objectVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts braking parameters (brake pressure, application duration) based on real-time conditions such as vehicle speed, steering angle, and soil type. This allows the tractor to achieve tight turns while controlling wheel slip to prevent headland damage through electronic control of brake actuation timing and intensity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses sensors to monitor wheel speed, steering angle, and vehicle velocity, feeding this information back to the electronic control unit. The ECU continuously adjusts brake application based on this feedback to maintain optimal slip levels, enabling tight turns without excessive soil compaction or wheel locking

Inventive Principle:
Principle #23Feedback

2Ease of operation

If manual independent brake control is used for tight turns, then turning capability is improved, but operator skill requirement increases and safety risks arise during on-road use

Engineering Contradiction:
Improveturning capabilityVSAvoidsafety
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system automatically performs the complex braking maneuvers required for tight turns without operator intervention. The electronic control unit autonomously activates and modulates the brakes based on sensor inputs, eliminating the need for skilled manual brake control while maintaining turning capability and improving safety through consistent, error-free operation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical brake control with an electronic braking system featuring electronic actuators controlled by an ECU. This substitution eliminates the need for dual brake pedals and manual coordination, providing automated differential braking that enhances both ease of operation and safety by preventing operator error during turning maneuvers

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

3Length of moving object

If wheel locking is permitted during braking steering, then tight turn radius is achieved, but loss of traction and control occurs

Engineering Contradiction:
Improveturn radiusVSAvoidtraction control
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The system precisely controls brake pressure parameters to maintain wheel slip within an optimal range (typically 10-30%). The electronic actuators modulate brake force dynamically during the turning maneuver, applying enough pressure to achieve tight turn radius while preventing complete wheel locking that would cause loss of traction and directional control

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enables precise, damage-free headland turns and improves safety by automating the braking process, reducing the risk of accidents and allowing for high-speed operation without the need for dual brake pedals, thus enhancing the tractor's efficiency and safety.

Implementation Method 1

a respective brake, for each driven, ground-engaging member, that is operable under the control of driven member brake commands generated in a controller so as to provide a respective braking effort for each of the driven, ground-engaging members

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2475558B1A vehicle with brake steering
Publication Date: 2017.06.07 CNH IND ITALIA SPA
  • EP2475558B1 patent drawingFigure 1
  • EP2475558B1 patent drawingFigure 2
  • EP2475558B1 patent drawingFigure 3

AI summary

A vehicle includes a frame, body or chassis defining left and right sides and comprising at least one source of motive power; at least one respective, driven, ground-engaging member supported on each said side of the vehicle so as to be moveable relative to the vehicle during motion of the vehicle; at least one driven member drive train for connecting the or each said source so as to cause movement of at least one of the driven, ground-engaging members and hence of the vehicle; a respective brake (10, 11), for each driven, ground-engaging member, that is operable under the control of driven member brake commands generated in a controller (12) so as to provide a respective braking effort for each of the driven, ground-engaging members; at least one ground- engaging, steerable member that defines a steering angle, relative to the vehicle, that is adjustable on the operation of one or more control members; at least one sensor for generating a steering angle signal (25) that is indicative of the steering angle; at least one sensor (23, 24) for generating a vehicle speed signal (31, 32) that is indicative of the vehicle speed relative to the ground; and at least one sensor for generating a respective driven member speed signal that is indicative of the movement speed relative to the vehicle of each driven, ground-engaging member. The controller (12) is capable of generating the driven member brake commands based on the steering angle (25) and vehicle speed signals together with a driven member slip estimation signal that is generated from the driven member speed signals (31, 32).