Method and apparatus for on-center steering and a fast response vehicle
Presented herein are systems and methods for controlling a response (e.g., a roll, a pitch) of a vehicle body to a driver input. In one aspect, a method for controlling the response of the vehicle body is presented, the method comprising receiving an input (e.g., a steering wheel input, a pedal input) from an operator of a vehicle and modifying an aspect (e.g., a roll angle, a pitch angle, a roll rate, a pitch rate) of the response of the vehicle body, the modified aspect having a value based, at least partially, on the input. In another aspect, a controlled vehicle is presented comprising a vehicle body and one or more actuators configured to apply a torque to the vehicle body, the torque having a direction and/or magnitude based, at least partially, on a driver input (e.g. steering command, braking command, and/or acceleration command).
1. A method for controlling a forced response of a vehicle body of a controlled vehicle to a particular command, the method comprising:
(a) receiving the particular command to perform a first maneuver with the controlled vehicle, wherein the particular command comprises at least one of: a steering command, a braking command, and an acceleration command;
(b) determining, based on the particular command, a particular target vehicle body response having a particular set of target aspects, wherein the particular set of target aspects comprises at least one of: a target direction, a target magnitude, a target rate;
(c) determining, based on the particular target vehicle body response, a first active force; and
(d) applying, to the vehicle body by one or more active suspension actuators, the first active force.
2. The method of claim 1 , wherein the forced response comprises motion having an active direction equal to the direction of the particular target vehicle body response.
3. The method of claim 2 , wherein the forced response comprises motion having an active rate equal to the rate of the particular target vehicle body response.
4. The method of claim 2 , wherein the forced response comprises motion having an active magnitude equal to the magnitude of the particular target vehicle body response.
5. The method of claim 1 , wherein step (b) comprises:
obtaining a model of a target vehicle comprising a target vehicle body, the model defining a target response of the target vehicle body as a function of at least one of: a reference steering command, a reference acceleration command, a reference braking command; and
computing the particular target vehicle body response by evaluating the particular command against the model.
6. The method of claim 5 , wherein the target vehicle has a passive or semi-active suspension system.
7. The method of claim 5 , wherein the target vehicle has a first yaw inertia and the controlled vehicle has a second yaw inertia larger than the first yaw inertia.
8. The method of claim 5 , wherein step (c) comprises:
determining a natural response to the command, wherein the natural response has a second set of aspects comprising at least one of: a natural direction, a natural magnitude, a natural target rate;
computing a difference between an aspect of the second set and an aspect of the first set; and
determining, based on the difference, the first force.
9. The method of claim 8 , wherein step (b) comprises:
determining a natural rate of the natural response;
wherein the forced response has a rate faster than the natural rate.
10. The method of claim 8 , wherein step (b) comprises:
determining a natural magnitude of the natural response;
wherein the forced response has a magnitude at least one of: equal to the natural magnitude, larger than the natural magnitude.
11. The method of claim 8 , wherein the first maneuver comprises a turn in a turning direction and the natural response includes roll away from the turning direction.
12. The method of claim 8 , wherein the first maneuver involves braking and the natural response is pitch in the forward direction.
13. The method of claim 5 , wherein the target vehicle is a virtual vehicle.
14. The method of claim 1 , wherein the first maneuver has a duration lasting from a first point in time to a second point in time, the method further comprising:
discontinuing application of the first force at a third point in time, wherein the third point is later than the first point and earlier than the second point.
15. A method for controlling a forced response of a body of a vehicle to a steering command, the method comprising:
rotating a steering wheel of a vehicle to a first position at a first rate of rotation;
determining, based on at least one of the first position and the first rate, a first active force;
applying, to the vehicle body by one or more active suspension actuators, the first active force.
16. The method of claim 15 , wherein rotating the steering wheel causes the vehicle to turn left, and wherein the first force is a torque having a clockwise direction.
17. The method of claim 15 , wherein rotating the steering wheel causes the vehicle to turn right, and wherein the first force is a torque having a counter clockwise direction.
18. A method for controlling a forced response of a body of a vehicle to an acceleration command, the method comprising:
changing the position of a pedal of the vehicle from a first position to a second position at a first rate of change, wherein the pedal is one of: an acceleration pedal, a brake pedal;
determining, based on at least one of the first position, the second position, and the first rate, a first active force; and
applying, to the vehicle body by one or more active suspension actuators, the first active force.
19. The method of claim 18 , wherein changing the position of the pedal causes the vehicle to accelerate in a forward direction, wherein the first force causes a rear end of the vehicle to lower vertically with respect to a front end of the vehicle.
20. The method of claim 18 , wherein changing the position of the pedal causes the vehicle to deaccelerate in a forward direction, wherein the first force causes a front end of the vehicle to lower vertically with respect to a rear end of the vehicle.