Vehicle seat with angle trajectory planning during large events

1. A method of controlling movement of a seat in a vehicle relative to the vehicle, comprising:

receiving a signal from at least one sensor positioned to detect movement of the vehicle;

based at least on the received signal, determining a desired displacement value of the seat relative to the vehicle;

determining whether the desired displacement value exceeds a threshold value;

in response to determining that the desired displacement value exceeds the threshold value, scaling the desired displacement value to calculate a scaled displacement value that is less than the desired displacement value; and

operating an actuator to displace the seat to the scaled displacement value.

2. The method of claim 1 , further comprising:

determining a maximum allowable displacement;

continuously determining an actual displacement of the seat; and

upon determining that the actual displacement of the seat at a given time equals or exceeds the maximum allowable displacement, operating the actuator to at least one of maintain and reduce the actual displacement of the seat.

3. The method of claim 1 , wherein the desired displacement value is a desired angle of rotation, the scaled displacement value is a scaled angle of rotation, and the threshold value is a threshold angle, and wherein scaling the desired displacement value to determine a scaled displacement value includes:

determining a maximum allowable angle of rotation;

calculating an index value based on the desired angle of rotation, the threshold angle, and the maximum allowable angle of rotation; and

determining a scaling factor based at least in part on the calculated index value.

4. The method of claim 3 , wherein determining the scaling factor based at least in part on the calculated index value comprises:

accessing an attenuation table that contains at least one scaling factor, wherein each scaling factor of the at least one scaling factor corresponds to a respective index value; and

determining the scaling factor by identifying a specific scaling factor from the attenuation table that most closely corresponds to the calculated index value, based on the calculated index.

5. The method of claim 4 , wherein the at least one scaling factor includes a range of values based on a ¼ sine wave.

6. The method of claim 3 , wherein scaling the desired displacement value to determine a scaled displacement value comprises calculating the scaled angle of rotation according to equation (2), wherein T is the threshold angle, M is the maximum allowable angle, F 1 is the scaling factor, and S is the scaled angle of rotation;

S=T +( M−T )* F 1   (equation 2).

7. The method of claim 1 , wherein the first desired displacement value is a first desired angle of rotation of the seat relative to a vehicle centerline, the scaled displacement value is a scaled angle of rotation, and the first threshold value is a first threshold angle of rotation, and wherein scaling the first desired displacement value to determine a scaled displacement value comprises scaling the first desired angle of rotation to determine the scaled angle of rotation.

8. A seat system of a vehicle, comprising:

a seat positioned at a first position relative to the vehicle;

an actuator arranged to move the seat relative to the vehicle;

a sensor configured to sense motion of the vehicle; and

a controller configured to:

receive a signal from the sensor, wherein the signal corresponds to a movement of the vehicle;

in response to the received signal, generate a signal to command the actuator to move the seat to a second position relative to the vehicle;

determine whether the second position exceeds a limit; and

upon determining that the second position exceeds a limit, scale the command signal.

9. The method of claim 1 , further comprising:

sensing a position of the seat relative to a floor of the vehicle; and

based on the sensed position, determining the threshold value.

10. The method of claim 2 , further comprising determining the maximum allowable displacement based on at least a position of the seat relative to an axis that intersects a floor of the vehicle.

11. The method of claim 3 , further comprising:

determining a maximum allowable angle of rotation;

in response to determining that an actual angle of rotation of the seat at a given time equals or exceeds the maximum allowable angle, operating the actuator so as to maintain or reduce the actual angle of rotation of the seat.

12. A seat system for a vehicle, comprising:

a seat configured to rotate relative to the vehicle;

an actuator configured to rotate the seat;

at least one sensor positioned to detect movement of the vehicle; and

a controller configured to:

receive a signal from the at least one sensor,

based on the received signal, determine a desired angle of rotation of the seat,

determine whether the desired angle exceeds a threshold angle,

in response at least to determining that the desired angle exceeds the threshold angle, scale the desired angle of rotation to determine a scaled angle of rotation;

calculate a value of a force at least partially based on the scaled angle of rotation; and

command the actuator to apply the force to the seat.

13. The seat system of claim 12 , wherein the controller is further configured to:

determine a maximum allowable angle of rotation;

monitor, over a period of time, an actual angle of rotation of the seat; and

upon determining that the actual angle of rotation of the seat at a given time equals or exceeds the maximum allowable angle of rotation, command the actuator to apply an adjusted force, wherein application of the adjusted force to the seat causes the seat to maintain or reduce its actual angle of rotation.

14. The seat system of claim 12 , wherein the controller is further configured to:

determine a maximum allowable angle of rotation of the seat;

calculate an index value based on the desired angle of rotation, the threshold angle, and the maximum allowable angle of rotation; and

determine a scaling factor based at least in part on the calculated index value.

15. The seat system of claim 14 , further comprising a memory storing an attenuation table having a plurality of scaling factors, wherein each of at least two scaling factors of the plurality of scaling factors corresponds to an index value, and wherein the controller is configured to determine the scaling factor by identifying a specific scaling factor of the plurality of scaling factors that most closely corresponds to the calculated index value.

16. The seat system of claim 15 , wherein the plurality of scaling factors include a range of values based on a ¼ sine wave.

17. The seat system of claim 15 , wherein the controller is configured to scale the desired angle of rotation to obtain the scaled angle of rotation by calculating the scaled angle of rotation according to equation (2), wherein T is the threshold angle, M is the maximum allowable angle, F 1 is the scaling factor, and S is the scaled angle of rotation;

S=T +( M−T )* F 1   (equation 2).

18. The vehicle seat of claim 8 , wherein the seat is configured to move along an axis that is fixed to the floor and intersects the floor of the vehicle, and the controller is configured to restrict movement of the seat so as to prevent interference with an interior of the vehicle.

19. The vehicle seat of claim 18 , wherein the controller is configured to determine a maximum command angle based on at least a position of the seat along the axis.

20. The seat system of claim 12 , wherein the seat is configured to move relative to an axis that intersects a floor of the vehicle, and the controller is configured to restrict movement of the seat to prevent interference with an interior of the vehicle.

21. The seat system of claim 20 , wherein the controller is configured to determine a maximum allowable angle of rotation of the seat relative to the axis.

22. The seat system of claim 21 , wherein the controller is configured to determine when the seat is rotated to an angle equal to or exceeding the maximum allowable angle, and in response to said determination, to command the actuator to cause the actuator to stop additional rotation of the seat.

23. The vehicle seat of claim 19 , wherein the controller is configured to scale the command signal by determining if the command signal has reached the maximum command angle and subsequently reducing the command signal.

24. The vehicle seat of claim 8 , wherein the controller is configured to generate a force command to move the seat based on at least the scaled command signal.

25. The vehicle seat of claim 8 , wherein the seat is configured to rotate relative to an axis fixed to the vehicle, wherein the first position is a first angle of rotation of the seat relative to the axis, wherein the command signal specifies a desired angle of rotation, and wherein the controller is configured to scale the command signal by causing the command signal to transition to a maximum command angle and to transition from the maximum command angle.