Distributed and generic control allocation for multi-unit vehicle combinations

A method performed in a master control allocator of a distributed control allocation system of a vehicle combination including a plurality of vehicle units, each vehicle unit including one or more wheel units and one or more actuators configured to provide at least one of torque and steering for the one or more wheel units, the master control allocator being communicatively connected to a plurality of slave control allocators each associated with a respective vehicle unit, the method being performed by processing circuitry of the master control allocator and comprising:

• receiving requested global forces for the vehicle combination as a whole;
• receiving at least one of vehicle unit-specific force-limitations and vehicle unit-specific moment-limitations of the vehicle units;
• calculating vehicle unit-specific desired forces for each slave control allocator currently connected to the master control allocator, by solving a vehicle combination-specific control allocation problem, wherein solving the vehicle combination-specific control problem includes attempting to distribute the requested global forces for the vehicle combination as a whole among the vehicle units in accordance with a vehicle combination-specific control efficiency matrix and subject to at least one of the received vehicle unit-specific force-limitations and the received vehicle unit-specific and moment-limitations, and wherein the vehicle combination-specific control efficiency matrix is defined based on one or more articulation angles between the vehicle units and an arrangement of coupling points in the vehicle units;
• and
• sending the calculated vehicle unit-specific desired forces to the respective one or more slave control allocators connected to the master control allocator.

A method performed in a slave control allocator of a distributed control allocation system of a vehicle combination including a vehicle unit, the vehicle unit including one or more wheel units and one or more actuators configured to provide at least one of torque and steering for the one or more wheel units, the slave control allocator being associated with the vehicle unit and communicatively connected to a master control allocator of the distributed control allocation system and to the one or more actuators, the method being performed by processing circuitry of the slave control allocator and comprising:

• receiving vehicle unit-specific desired forces for the vehicle unit from the master control allocator;
• receiving actuator-limitations of the one or more actuators;
• calculating at least one of vehicle unit-specific force-limitations and vehicle unit-specific moment-limitations for the vehicle unit based on the received actuator-limitations of the one or more actuators, and sending the calculated at least one of vehicle unit-specific force-limitations and vehicle unit-specific moment-limitations to the master control allocator;
• calculating a vehicle unit-specific control input for the vehicle unit based on the vehicle unit-specific desired forces, by solving, subject to at least the received actuator-limitations of the one or more actuators, a vehicle unit-specific control allocation problem;
• and
• controlling the one or more actuators connected to the slave control allocator based on the calculated vehicle-specific control input.