Camber modification for different driving surfaces
A control system ( 300 ) for controlling an actuator arrangement ( 104 ) of a vehicle ( 100 ), the actuator arrangement being capable of modifying a camber angle of at least one wheel of the vehicle, the control system comprising one or more controller ( 301 ), wherein the control system is configured to: receive ( 1004 ) surface information indicative of a low-traction surface over which the vehicle is travelling; and independence on receiving the surface information, control ( 1012 ) the actuator arrangement of the vehicle such that a wheel-to-surface contact patch of the at least one wheel is laterally moved relative to the vehicle as a result of camber modification.
1 . A control system comprising one or more processors configured to:
receive surface information indicative of a low-traction surface over which the vehicle is travelling;
monitor a trigger condition based on at least one criterion other than which surface is indicated by the surface information;
in dependence on the surface information indicating a low-traction surface and on satisfaction of the trigger condition, control an actuator arrangement of the vehicle by controlling active suspension actuators of an active suspension system to dynamically control a force-displacement relationship for individual wheels of the vehicle to modify a camber angle of at least one wheel of the vehicle such that a wheel-to-surface contact patch of the at least one wheel is laterally moved relative to the vehicle as a result of camber modification, the camber modification comprises oscillating camber modification, the active suspension actuators configured to independently vary a wheel-to-body distance at each of the wheels of the vehicle;
enable activation of the camber modification in dependence on the surface information indicating the low-traction surface;
not enable activation of the camber modification in dependence on the surface information indicating a high-traction surface; and
control a frequency of the oscillating camber modification in dependence on at least one of the surface information and traction information indicating vehicle progress.
2 . The control system of claim 1 , configured to determine a phase pattern of the oscillating camber modification in dependence on traction information; and determine the phase pattern based on a determination between at least two of the following options: inducing oscillating lateral movement of a body of the vehicle; inducing oscillating yaw of the body; and symmetrical camber changes without inducing movement of the body.
3 . The control system of claim 2 , configured to
determine oscillating yaw when the traction information indicates that the vehicle has traction, and
determine lateral movement or symmetrical camber changes when the traction information indicates that the vehicle lacks traction.
4 . The control system of claim 1 , wherein the camber modification comprises steady state camber modification.
5 . The control system of claim 4 , configured to
enable the steady state camber modification at least when the surface information indicates ruts, and
not enable the steady state camber modification if the surface information does not indicate ruts.
6 . The control system of claim 1 , wherein the control system is configured to monitor the trigger condition by at least one of:
enabling a human-machine interface, wherein the trigger condition is satisfied by detecting activation of the human-machine interface; and
determining from received traction information whether traction of the vehicle is predicted or detected to fall below a traction threshold.
7 . The control system of claim 1 , wherein the control system is configured to monitor the trigger condition by determining from traction information whether vehicle progress is below a threshold, wherein vehicle progress is indicated by at least one of vehicle speed and a derivative of vehicle speed.
8 . The control system of claim 1 , wherein the actuator arrangement comprises active camber actuators.
9 . The control system of claim 1 , wherein
the actuator arrangement comprises active suspension actuators of an active suspension system, and
the active suspension actuators are configured to dynamically control a force-displacement relationship for individual wheels of the vehicle.
10 . The control system of claim 1 , wherein the surface information comprises at least one of:
a selected terrain mode of the vehicle indicating the low-traction surface; and
information obtained from at least one topography sensor indicating the low-traction surface.
11 . The control system of claim 1 , configured to enable the oscillating camber modification when the surface information indicates a first surface, and not when the surface information indicates a second surface.
12 . The control system of claim 1 , configured to cause oscillating steering angle changes of steerable wheels of the vehicle while the camber is modified.
13 . A vehicle comprising the control system of claim 1 .
14 . A control system configured to:
receive surface information indicative of a surface over which a vehicle is travelling;
in dependence on the surface information indicating a low-traction surface, control an actuator arrangement by controlling active suspension actuators of an active suspension system to dynamically control a force-displacement relationship for individual wheels of the vehicle to modify a camber angle of at least one wheel of the vehicle such that wheel-to-surface contact patches of the wheels are laterally moved relative to the vehicle as a result of camber modification, wherein the camber modifications comprise oscillating camber modifications that are different in at least one of amplitude and sign for different ones of the plurality of wheels, the active suspension actuators configured to independently vary a wheel-to-body distance at each of the wheels of the vehicle;
enable activation of the camber modification in dependence on the surface information indicating the low-traction surface;
not enable activation of the camber modification in dependence on the surface information indicating a high-traction surface; and
control a frequency of the oscillating camber modification in dependence on at least one of the surface information and traction information indicating vehicle progress.
15 . A method of controlling an actuator arrangement of a vehicle, the actuator arrangement being capable of modifying a camber angle of at least one wheel of the vehicle, the method comprising:
receiving surface information indicative of a surface over which the vehicle is travelling;
monitoring a trigger condition based on one or more criteria other than which surface is indicated by the surface information;
in dependence on the surface information indicating a low-traction surface and on satisfaction of the trigger condition, controlling an actuator arrangement of the vehicle by controlling active suspension actuators of an active suspension system to dynamically control a force-displacement relationship for individual wheels of the vehicle to modify a camber angle of at least one wheel of the vehicle such that a wheel-to-surface contact patch of the at least one wheel is laterally moved relative to the vehicle as a result of camber modification, the camber modification comprises oscillating camber modification, the active suspension actuators configured to independently vary a wheel-to-body distance at each of the wheels of the vehicle;
enabling activation of the camber modification in dependence on the surface information indicating the low-traction surface;
not enabling activation of the camber modification in dependence on the surface information indicating a high-traction surface; and
controlling a frequency of the oscillating camber modification in dependence on at least one of the surface information and traction information indicating vehicle progress.
16 . A non-transitory storage medium containing instructions that, when executed by at least one processor, cause the processor to perform the method of claim 15 .