Vehicle control based on dynamically configured longitudinal wheel slip limits
A computer-implemented method performed in a vehicle control unit for controlling motion of a heavy-duty vehicle, the method comprising obtaining a vehicle motion request, wherein the vehicle motion request is indicative of a target curvature c req and a target acceleration a req , determining a motion support device (MSD) control allocation (T i /λ i /ω i /δ i ) based on the vehicle motion request, determining a dynamic longitudinal wheel slip limit (λ lim /ω lim ) based on the vehicle motion request and separately from the MSD control allocation, where the dynamic longitudinal wheel slip limit increases with a decreasing target curvature, and controlling the motion of the heavy-duty vehicle based on the MSD control allocation constrained by the dynamic longitudinal wheel slip limit.
1 . A computer-implemented method performed in a vehicle control unit for controlling motion of a heavy-duty vehicle, the method comprising:
obtaining a vehicle motion request, wherein the vehicle motion request is indicative of a target curvature and a target acceleration;
determining a motion support device (MSD) control allocation based on the vehicle motion request;
determining a dynamic longitudinal wheel slip limit based on the vehicle motion request and separately from the MSD control allocation, where the dynamic longitudinal wheel slip limit increases with a decreasing target curvature, and where the dynamic longitudinal wheel slip limit is determined by minimizing local Hamiltonian functions at one or more wheels; and
controlling the motion of the heavy-duty vehicle based on the MSD control allocation constrained by the dynamic longitudinal wheel slip limit.
2 . The method of claim 1 , comprising obtaining the vehicle motion request from a driver input and/or from an autonomous or semi-autonomous traffic situation management (TSM) function.
3 . The method of claim 1 , comprising determining the MSD control allocation based on a B-matrix control allocation method.
4 . The method of claim 1 , comprising determining the MSD control allocation at least partly as a target wheel torque.
5 . The method of claim 1 , comprising determining the MSD control allocation at least partly as a target wheel slip or wheel speed relative to ground.
6 . The method of claim 1 , comprising determining the MSD control allocation at least partly as a target steering angle.
7 . The method of claim 1 , comprising determining the dynamic longitudinal wheel slip limit based on a current wheel slip angle and on a required lateral force, where the dynamic longitudinal wheel slip limit decreases if the current wheel slip angle increases.
8 . The method of claim 1 , comprising determining a dynamic steering angle limit in addition to the dynamic longitudinal wheel slip limit.
9 . The method of claim 1 , wherein each minimization of local Hamiltonian functions at one or more wheels comprises a linear search of a tire force curve.
10 . The method of claim 1 , comprising determining the dynamic longitudinal wheel slip limit based on a stability condition involving a maximum acceptable yaw moment of the vehicle.
11 . A computer program product comprising program code for performing, when executed by a computer, the steps of claim 1 .
12 . A non-transitory computer readable medium comprising a computer program comprising program code, which when executed by a computer, performs the steps of claim 1 .
13 . A control unit, comprising:
processing circuitry;
an interface coupled to the processing circuitry; and
a memory coupled to the processing circuitry, wherein the memory comprises machine readable computer program instructions that, when executed by the processing circuitry, causes the control unit to perform operations of:
obtaining a vehicle motion request, wherein the vehicle motion request is indicative of a target curvature and a target acceleration;
determining a motion support device (MSD) control allocation based on the vehicle motion request;
determining a dynamic longitudinal wheel slip limit based on the vehicle motion request and separately from the MSD control allocation, where the dynamic longitudinal wheel slip limit increases with a decreasing target curvature, and where the dynamic longitudinal wheel slip limit is determined by minimizing local Hamiltonian functions at one or more wheels; and
controlling the motion of the heavy-duty vehicle based on the MSD control allocation constrained by the dynamic longitudinal wheel slip limit.
14 . A heavy-duty vehicle comprising the control unit of claim 13 .