Outboard Motor Steering Control for Collision Prevention

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Solution Overview

Problem

In watercrafts with multiple outboard motors not coupled by a tie bar, significant differences in steering angles can lead to collisions or impaired steering performance due to variations in friction and engine angular displacement speeds.

Innovation Solution

An outboard motor control system with a target steering angle setting section, actuators, and an actual steering angle detecting section, which controls the steering operation to suppress the enlargement of steering angle differences between adjacent motors, using collision limit values to adjust target steering angles and prevent collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If individual target steering angles are set for each outboard motor, then steering flexibility is improved, but the risk of collision between motors increases due to large steering angle differences

Engineering Contradiction:

Improvesteering flexibilityVSAvoidcollision risk

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The control device continuously monitors the actual steering angles of all outboard motors and compares them against target angles. When the steering angle difference between adjacent motors exceeds a predetermined threshold, the system automatically adjusts the target steering angles to prevent collision, thus maintaining both flexibility and safety through real-time feedback control

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts target steering angles based on real-time conditions. When collision risk is detected through steering angle difference monitoring, the target angles are modified to reduce the difference between adjacent motors. This dynamic adjustment allows the system to maintain individual steering control while adaptively preventing collision scenarios

Inventive Principle:

Principle #15Dynamics

2Productivity

If steering angles of adjacent outboard motors differ greatly, then individual motor performance is optimized, but parts of the motors may collide during steering operation

Engineering Contradiction:

Improvemotor performanceVSAvoidparts collision

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The control device proactively prevents parts collision by monitoring steering angle differences before collision occurs. When the difference between adjacent motors exceeds the predetermined threshold, the system preemptively adjusts target steering angles to reduce the difference, thereby preventing the harmful effect of parts collision before it can happen

Inventive Principle:

Principle #9Preliminary anti-action

3Adaptability or versatility

If replacement outboard motors are installed, then system adaptability is improved, but friction differences cause steering angle difference enlargement

Engineering Contradiction:

Improvemotor replacement capabilityVSAvoidsteering angle consistency

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The control device continuously monitors actual steering angles of all motors including replacements. When friction differences cause steering angle differences to exceed the threshold, the system detects this through feedback and automatically adjusts target angles to maintain consistency, thereby accommodating motor replacements while preserving steering stability

Inventive Principle:

Principle #23Feedback

4Device complexity

If no tie bar coupling is used, then device complexity is reduced, but steering angle coordination becomes difficult leading to collisions

Engineering Contradiction:

Improvecoupling structureVSAvoidsteering coordination

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces the mechanical tie bar coupling system with an electronic control system. The control device uses sensors to monitor steering angles and electronically coordinates the motors through control signals, eliminating the need for physical coupling while maintaining or improving steering coordination and collision prevention

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2813422B1Outboard motor control system

Publication Date: 2017.07.05 YAMAHA MOTOR CO LTD

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AI summary

Outboard motors are mounted to a stern of the watercraft. The outboard motors can be steered independently. A target steering angle setting section is configured to set a target steering angle for each of the outboard motors. Actuators are configured to steer the outboard motors such that the steering angle each of the outboard motors equals a target steering angle. An actual steering angle detecting section is configured to detect an actual steering angle of each of the outboard motors. A control section is configured to control the steering operation of the outboard motors such that, when a steering angle difference constituting a difference between the actual steering angles of adjacently arranged outboard motors becomes equal to or larger than a prescribed value, enlargement of the steering angle difference is suppressed.