Ship Speed Control with Multi-Stage Rate Adjustment
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Solution Overview
Problem
Conventional ship navigation control systems require pre-defined speed-control maps, limiting adjustable acceleration and deceleration, and consuming computer resources, making them inefficient in tracking user-set speed settings.
Innovation Solution
A speed control device with a target speed setting module and a change rate adjusting module that adjusts the rate of change in multiple stages without a pre-defined map, allowing for adjustable acceleration and deceleration based on user preferences, and includes a throttle opening control mechanism to improve ride comfort and tracking performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pre-defined speed-control map is used to control engine speed, then the ship speed can follow the target ship speed, but computer resources are consumed and acceleration and deceleration are not easily adjustable
Solution Approach 1:
The patent extracts the essential control logic from the complex pre-defined speed-control map by implementing a simplified control algorithm that calculates target engine speed directly from target ship speed and actual ship speed using proportional control, eliminating the need for large lookup tables and reducing computer resource consumption while maintaining speed tracking performance
Solution Approach 2:
The patent changes the control parameter from fixed map-based values to dynamically adjustable proportional control parameters (Kp), allowing acceleration and deceleration characteristics to be easily modified by changing parameter values rather than reprogramming the entire control map, thus improving adaptability while reducing system complexity
2Reliability
If a pre-defined speed-control map is used, then speed tracking is achieved, but acceleration and deceleration are not easily adjustable according to preferences
Solution Approach 1:
The patent implements dynamic control parameters that can be adjusted in real-time based on operating conditions and user preferences, allowing the proportional control gain (Kp) to be modified to change acceleration and deceleration characteristics, making the system adaptable to different preferences while maintaining reliable speed tracking
Solution Approach 2:
The patent enables easy adjustment of acceleration and deceleration by allowing users to modify control parameters (Kp, Ki, Kd) without changing the fundamental control structure, providing versatility in tuning the system response while maintaining the reliability of speed following through the established control algorithm
3Speed
If the target speed changes rapidly to follow user setting, then response is fast, but overshoot occurs when target speed approaches the speed setting
Solution Approach 1:
The patent implements feedback control by continuously monitoring the difference between target ship speed and actual ship speed, and using this error signal to adjust the target engine speed through proportional (and optionally integral and differential) control, enabling the system to respond quickly to speed changes while automatically reducing the rate of change as the actual speed approaches the target, thus preventing overshoot
Solution Approach 2:
The patent makes the target engine speed dynamic rather than directly equating it to target ship speed, allowing the system to adjust the rate of change of target engine speed based on the current error and its rate of change, enabling fast response when error is large while providing smooth deceleration of the target speed as the error decreases, thereby preventing overshoot
Data Source
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AI summary
A speed control device which is satisfactory in response and tracking to a speed setting, and can adjust an acceleration-and-deceleration feel according to preferences, is provided. The speed control device 6 controls a speed of a ship so that the speed automatically follows a speed setting set by a ship operator. The speed control device 6 includes a target speed setting module 63 and a change rate adjusting module 64. The target speed setting module 63 sets a target speed that is a target of the speed of the ship to follow, for every unit time, according to the speed setting, to change the target speed based on a given rate of change. The change rate adjusting module 64 decreases the rate of change by adjusting the rate of change at multiple stages, when the target speed set by the target speed setting module 63 approaches the speed setting.