HAPTIC ALERT WAVEFORM GENERATION METHOD AND SYSTEM

• US 20110001616A1
• Filed: 02/27/2009
• Published: 01/06/2011
• Est. Priority Date: 04/30/2008
• Status: Active Grant

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Nathan, John F., Kennedy, Karl, Karumathil, Santosh
• Granted Patent: US 8,686,940 B2
• Time in Patent Office: Days
• US Class Current: 340/438
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user

Abstract

Haptic alert waveform generation method and system for use with haptic actuators that impart haptic sensations according to a waveform of an input signal used to control the haptic actuator. The shape and/or amplitude of the waveform may be controlled according to information collected from various vehicle systems, allowing virtually any type of waveform to generate and used to impart virtually any type of haptic sensations.

Claims

1. A method of imparting a haptic sensation using a haptic actuator included within a vehicle seat comprising:

determining the haptic sensation to be imparted to the occupant;

determining a waveform that corresponds to the determined haptic sensation;

generating a first signal including a first duty cycle that corresponds with the determined waveform, the first duty cycle specifying a first frequency at which the first signal is alternated between high and low states;

generating a second signal including a second duty cycle that corresponds with the determined waveform, the second duty cycle specifying a second frequency at which the second signal is alternated between high and low states;

combining the first and second signals to produce a third signal that includes the determined waveform; and

driving the haptic actuator with the third signal.

2. The method of claim 1 further comprising determining the haptic sensation from information collected by one or more vehicle systems of a vehicle having the vehicle seat.

3. The method of claim 2 further comprising increasing an intensity of the haptic sensation if the information indicates persistence of an event triggering a need to impart the haptic sensation.

4. The method of claim 3 further comprising varying the second duty cycle and not the first duty cycle when increasing the intensity of the haptic sensation.

5. The method of claim 2 further comprising determining the haptic sensation to be of a first type when the information indicates a lane departure and to be of a second type when the information indicates a rear park obstruction.

6. The method of claim 5 further comprising using the same first duty cycle for both of the first and second types of haptic sensations.

7. A method of driving a haptic actuator included within a vehicle seat comprising:

generating a first signal having a square waveform;

generating a second signal having a square waveform;

combining the first and second signals to form a third signal having a non-square waveform; and

driving the haptic actuator with the third signal.

8. The method of claim 7 further comprising generating the first and second signals to alternate between high and low states according to respective first and second duty cycles.

9. The method of claim 8 further comprising matching the second duty cycle to the first cycle to cause the third signal to have a ramped waveform during a period when both of the first and second signals are high.

10. The method of claim 8 further comprising matching the second duty cycle to the first cycle to cause the third signal to have a sinusoidal waveform during a period when both of the first and second signals are high.

11. The method of claim 8 further comprising matching the second duty cycle to the first cycle to cause the third signal to have a ramped waveform for a portion of a period when both of the first and second signals are high and to have a sinusoidal waveform for another portion of the period.

12. The method of claim 8 further comprising matching the second duty cycle to the first cycle to cause the third signal to have a ramped waveform during a first period when both of the first and second signals are high and to have a sinusoidal waveform during a second period when both of the first and second signals are high.

13. The method of claim 8 further comprising setting the first duty cycle to cause the first signal to be in the high state throughout an event period during which the haptic actuator is to be driven.

14. The method of claim 13 further comprising setting the second duty cycle to cause the second signal to experience at least two high states and at least two low states throughout the event period.

15. The method of claim 14 further comprising varying a duration during which the second signal is in the high state for at least two cycles falling within the event period.

16. The method of claim 7 further comprising generating the first and second signals with at least one pulse-width modulator (PWM).

17. The method of claim 7 wherein the vehicle seat is included within a vehicle having a number of vehicle systems, and wherein the method further comprises generating the first and second signals according to information collected from one or more vehicle systems, the information representing a type of haptic sensation to be produced when driving the haptic actuator.

18. A vehicle seating system for use within a vehicle having a number vehicle systems for controlling or monitoring a number of vehicle operations, the system comprising:

a first pulse-width modulator (PWM) configured to output a first signal;

a second pulse-width modulator (PWM) configured to output a second signal;

an logical circuit configured to combine the first and second signal to form a third signal, the third signal having a waveform defined the combination of the first and second signals; and

a haptic actuator operable in response to the third signal to impart a haptic sensation to an occupant within a seat of the vehicle.

19. The system of claim 18 wherein the first and second PWMs generate square waves at equal amplitudes and different duty cycles to control the desired waveform.

20. The system of claim 19 further comprising a controller configured to control the first and second PWMs to output the first and second signal according to information collected by the vehicle systems.