Model Predictive Obstacle Control Using a Virtual Obstacle
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Solution Overview
Problem
Existing control systems that use evaluation functions with obstacle evaluation terms may fail to adequately avoid collisions when the moving body encounters multiple obstacles or when it comes into a stationary state, leading to potential detours in the obstacle avoidance route.
Innovation Solution
A control device that incorporates a model prediction control system, which acquires the positions of actual obstacles and uses a prediction model to calculate control inputs. When multiple obstacles are present, the system introduces a virtual obstacle positioned between them, adjusting the evaluation function to minimize collisions by using a virtual obstacle evaluation term and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the evaluation function including the obstacle evaluation term for each obstacle is used, then the moving body can avoid obstacles, but the moving body may come into a stationary state or make large detours when multiple obstacles are present
Solution Approach 1:
The patent introduces a virtual obstacle as an intermediary element between actual obstacles. The virtual obstacle serves as a mediator that guides the moving body around multiple actual obstacles without requiring direct interaction with each obstacle's evaluation term, thereby preventing stationary states and reducing detour size while maintaining reliable obstacle avoidance
Solution Approach 2:
The patent changes the parameter representation from using individual obstacle evaluation terms to using a virtual obstacle position parameter. By representing the combined effect of multiple obstacles through a single virtual obstacle position, the system achieves more efficient path planning that avoids stationary states and large detours while maintaining collision avoidance
2Device complexity
If the evaluation function including the obstacle evaluation term is simply used, then the control system remains simple, but the collision with the obstacle cannot be avoided suitably in complex scenarios
Solution Approach 1:
The virtual obstacle acts as an intermediary that simplifies the control system structure while improving collision avoidance reliability. Instead of managing multiple obstacle evaluation terms, the system uses a single virtual obstacle representation that encapsulates the combined obstacle information, reducing computational complexity while enhancing avoidance performance in multi-obstacle scenarios
Solution Approach 2:
The patent creates a virtual copy (virtual obstacle) that represents the combined effect of multiple actual obstacles. This copy simplifies the control calculations by replacing complex multi-obstacle interactions with a single virtual entity, thereby reducing system complexity while maintaining or improving collision avoidance reliability
Data Source
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AI summary
A model prediction control part (12) of a control device (10) includes an obstacle avoidance control unit that operates when there are a plurality of actual obstacles to be avoided. The obstacle avoidance control unit decides the position of a virtual obstacle from the positions of the plurality of actual obstacles acquired by an acquisition part (11) so as to be positioned between the plurality of actual obstacles, and performs model prediction control by using, as the stage cost, the addition result of a standard cost and a virtual obstacle evaluation term for which a prescribed function, which uses, as parameters, at least the position of the virtual obstacle and the position of a moving body, is multiplied by a virtual obstacle weight. Using this configuration, when the moving body is caused to follow with respect to a target trajectory by the model prediction control, a collision with an obstacle can be avoided suitably.