Predictive Relative Motion Control for Offshore Docking
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Solution Overview
Problem
In the offshore industry, operations between moving objects, such as ships and platforms, are hindered by unpredictable movements due to wave motion and weather conditions, leading to safety risks and financial losses, as existing systems struggle with effective movement compensation and time delays in reacting to disturbances.
Innovation Solution
A system with sensors and actuators, utilizing a control unit with prediction and interpolation modules to improve movement compensation, allowing for real-time adjustment of object positions and reducing time delays, enabling better compensation quality even under adverse weather conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a control system with signal processing is used to compensate movement between objects, then the compensation quality is improved, but time delays occur due to processing requirements
Solution Approach 1:
The prediction module calculates future movement data elements before they occur, allowing the control system to prepare compensation actions in advance. This predictive approach transforms the reactive signal processing into a proactive control mechanism, eliminating the inherent time delay while maintaining high compensation quality.
Solution Approach 2:
The system uses actual movement data elements as feedback to continuously update the prediction model. By feeding back the difference between predicted and actual movements, the system refines its predictions and improves compensation accuracy over time, maintaining high precision without sacrificing response speed.
2Device complexity
If sensors record raw data at low sampling rates to reduce data volume, then device complexity is reduced, but the control input frequency is insufficient for effective compensation
Solution Approach 1:
The prediction module acts as an intermediary between the low-rate sensor data and the high-rate control system. It generates additional movement data elements at the required control frequency by interpolating and predicting intermediate values, effectively decoupling the sensor sampling rate from the control input frequency.
Solution Approach 2:
The system changes the temporal parameters of the control input by generating multiple predicted movement data elements between actual sensor measurements. This parameter transformation allows the control system to operate at high frequency while sensors operate at low frequency, resolving the contradiction between device simplicity and control effectiveness.
Data Source
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AI summary
Disclosed is the control of one object relative to a second, for example, stationary, object. Preferably, no markings or sensors are required on the second object. Preferably, means for non-contact position determination are provided on the first object. These means include, for example, a camera or video camera and/or a lidar. Prediction is preferably used in the control process to compensate for time delays. Alternatively or additionally, interpolation can be provided to achieve a higher frequency of the actual value input for the control system.