Multi-Unit Vehicle Control Allocation for Non-Counteracting Actuator Forces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control allocation methods in multi-unit vehicle combinations fail to optimize energy efficiency due to actuators working against each other, leading to inefficient energy consumption and counteracting forces within the vehicle units.
Innovation Solution
A method that takes into account the capabilities of actuators to define a reference control input, ensuring that forces generated by different vehicle units contribute equally and do not counteract each other, thereby optimizing energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If control allocation is performed without considering actuator capabilities, then the control problem can be solved mathematically, but actuators generate counteracting forces leading to energy inefficiency
Solution Approach 1:
The reference control input is calculated in advance by solving an optimization problem that minimizes the difference between the reference and actual control inputs while considering actuator capabilities. This preliminary calculation ensures that actuators are assigned forces that do not counteract each other, preventing energy waste before the control execution occurs.
Solution Approach 2:
The method changes the parameter of reference control input from a simple zero vector to an optimized vector that reflects actuator capabilities and coordination requirements. By adjusting this parameter based on system characteristics, the control allocation achieves energy efficiency without requiring complex real-time adjustments during operation.
2Power
If multiple actuators are distributed among vehicle units, then propulsion capability is improved, but coordination between units becomes complex leading to counteracting forces
Solution Approach 1:
The control allocation system uses feedback from actuator capabilities and system state to continuously adjust the reference control input. This feedback mechanism ensures that distributed actuators across multiple vehicle units coordinate their forces effectively, maintaining propulsion capability while preventing counteracting forces through adaptive coordination.
Solution Approach 2:
The control allocation method provides a universal framework that works for any distribution of actuators across vehicle units. The optimization-based reference control input calculation can handle different configurations of propulsion and braking actuators, making the system adaptable to various multi-unit combinations without requiring configuration-specific coordination logic.
3Productivity
If conventional control allocation methods are used, then computational simplicity is maintained, but energy waste occurs due to counteracting forces from actuators
Solution Approach 1:
The optimization problem for calculating reference control input is solved in advance, before real-time control execution. This preliminary computation captures the energy efficiency considerations without burdening the real-time control loop, maintaining computational efficiency during operation while eliminating energy waste through optimized force distribution.
Solution Approach 2:
The method creates an optimized reference control input that serves as an ideal template for actuator coordination. This reference vector acts as a copy of the desired force distribution that accounts for energy efficiency, which can then be tracked by simpler real-time controllers without requiring complex optimization calculations during execution.
Data Source
Figure 1A~1B
Figure 1C~3A
Figure 3B~4B
AI summary
A method (300) of control allocation in a multi-unit vehicle combination is provided, wherein the units (110a, 110b) include actuators configured to generate propulsion and/ or braking forces. The method includes receiving a virtual control input (v) for the vehicle combination as a whole, solving (320) a control allocation problem to find a true control input (u) for the actuators, including attempting to minimize a difference between the true control input and a reference control input (u ref ). The method includes controlling the actuators based on the true control input. In particular, the method includes generating (330) the reference control input such that a) capabilities ( u and ū) of the actuators are taken into account, and b) such that a longitudinal force contribution of one vehicle unit does not counteract the contribution of another vehicle unit. A controller, vehicle unit, vehicle unit combination, computer program and computer program product are also provided.