Hierarchical Control Allocation for Reconfigurable Multi-Unit Vehicles
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Solution Overview
Problem
Conventional control allocators for multi-unit vehicle combinations are inflexible and require re-development when vehicle configurations change, such as adding or removing trailers or actuators, due to their specific tailoring to a particular configuration.
Innovation Solution
A distributed control allocation system with a master control allocator and slave control allocators, dividing the control allocation into vehicle combination-specific and vehicle unit-specific levels, allowing for generic adaptation to configuration changes without re-development.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional control allocators are tailored specifically to a particular vehicle combination configuration, then control precision is improved, but adaptability deteriorates requiring re-development when configuration changes
Solution Approach 1:
The control allocator is divided into a master control allocator that handles vehicle combination-level control and multiple slave control allocators that handle individual vehicle unit-level control. This segmentation allows each component to be independently configured and modified without affecting the entire system, enabling adaptability when vehicle configurations change while maintaining control precision through specialized sub-allocators.
Solution Approach 2:
The master control allocator is designed with a generic interface that can accommodate different vehicle combination configurations through standardized communication protocols with slave allocators. This universal design allows the same master allocator to work with various vehicle configurations (different numbers and types of trailers) without requiring re-development, while slave allocators provide configuration-specific control expertise.
2Adaptability or versatility
If the number of controllable degrees of freedom increases in complex vehicle combinations, then control capability is improved, but control problem complexity increases making the system over-actuated
Solution Approach 1:
The control allocation problem is segmented into two hierarchical levels: vehicle combination-level control (master allocator) and vehicle unit-level control (slave allocators). This segmentation reduces the complexity of the overall control problem by breaking it into smaller, more manageable sub-problems, each with fewer degrees of freedom to consider.
Solution Approach 2:
The control architecture introduces a hierarchical dimension to the control problem, organizing control decisions across two levels (combination-level and unit-level) rather than treating all control variables at a single level. This dimensional organization simplifies the control allocation mathematics by reducing the size of optimization problems at each level compared to a monolithic approach.
3Ease of operation
If a single master control allocator controls all actuators in all vehicle units, then centralized control is achieved, but system complexity and re-development requirements increase
Solution Approach 1:
The centralized control function is segmented between a master control allocator that manages overall vehicle combination control and slave control allocators that manage individual vehicle unit actuators. This segmentation maintains the benefits of centralized coordination while distributing the computational burden and reducing the complexity of any single control component.
Solution Approach 2:
Slave control allocators act as intermediaries between the master control allocator and individual vehicle unit actuators. These intermediary components translate high-level combination-level control commands into unit-specific actuator commands, reducing the complexity of direct master-to-actuator control while maintaining centralized coordination through standardized communication interfaces.
Data Source
AI summary
A method of distributed control allocation in a vehicle combination including multiple vehicle units is provided, in which a master control allocator solves a combination-specific control allocation problem to perform control allocation on a combination level, and each of a plurality of slave control allocators receives unit-specific virtual control inputs from the master control allocator and then performs control allocation on vehicle unit level to control actuators of an associated vehicle unit. A method performed in a master control allocator, a method performed in a slave control allocator, a distributed control allocation system, a master control allocator, a slave control allocator, a vehicle combination, a vehicle unit, and computer programs and computer program products are also provided.