Active material based haptic alert system

• US 20070109104A1
• Filed: 10/30/2006
• Published: 05/17/2007
• Est. Priority Date: 11/16/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Johnson, Nancy, Browne, Alan, Altan, Osman, Repa, Brian
• Granted Patent: US 7,714,701 B2
• Time in Patent Office: Days
• US Class Current: 340/407.100
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: B60W 50/16 Tactile feedback to the driver, e.g. vibration or force feedback to the driver on the steering wheel or the accelerator pedal

Abstract

A haptic alert system generally includes an active material based actuator for providing the haptic alert. The active material based actuators refer to the use of several different classes of active materials all of which exhibit a change in at least one attribute such as dimension, shape, and/or flexural modulus when subjected to at least one of many different types of applied activation signals, examples of such signals being thermal, electrical, magnetic, stress, and the like.

Claims

1. A haptic alert system, comprising:

an active material in operative communication with a vehicle surface, the active material adapted to reversibly change at least one attribute in response to an applied activation signal, wherein the vehicle surface variously vibrates, displaces, changes stiffness, and/or exerts a force on a contacting portion of a person in contact with the vehicle surface with the change in the at least one attribute of the active material; and

a controller in communication with active material, wherein the controller includes instructions to selectively apply the activation signal, wherein the vehicle surface has at least one property that changes with the change in the at least one attribute of the active material.

2. The system of claim 1, wherein the at least one attribute undergoing reversible change is a dimension, a shape, a shear force, a shape orientation, a flexural modulus, a phase of matter, or a combination comprising one or more of the foregoing properties.

3. The system of claim 1, wherein the active material is a shape memory alloy, a ferromagnetic shape memory alloy, a shape memory polymer, a magnetorheological fluid, an electroactive polymer, a magnetorheological elastomer, an electrorheological fluid, a piezoelectric material, or a combination comprising at least one of the foregoing active materials.

4. The system of claim 1, wherein the vehicle surface defines a tactile surface in operative communication with an occupant of the vehicle.

5. The system of claim 1, wherein the vehicle surface defines a seat surface.

6. A method for alerting an occupant of a vehicle of a condition, the method comprising:

producing an activation signal with an activation device; and

applying the activation signal to an active material in operative communication with a vehicle surface and causing a change in at least one property of the active material, wherein the change in the at least one property is effective to vibrate, displace, and/or change a stiffness property to the vehicle surface.

7. The method of claim 6, wherein vibrating the vehicle surface comprises varying a vibration frequency, a vibration amplitude, or any combination of the vibration frequency, and the vibration amplitude.

8. The method of claim 6, wherein producing the activation signal comprises detecting a condition with selected one of a sensor, a combined GPS/map based, and/or a telecommunication means.

9. The method of claim 6, wherein the vehicle surface comprises a brake pedal, a steering wheel, a seat, an accelerator, a floor, an arm rest, a console, and combinations comprising at least two or more of the foregoing vehicle surfaces.

10. The method of claim 6, wherein producing the activation signal comprises sensing an impact event or pre-impact event.

11. The method of claim 10, wherein sensing is accomplished with a pre-impact sensor.

12. The method of claim 6, wherein the activation signal is a thermal activation signal, a magnetic activation signal, an electric activation signal, a chemical activation signal, or a combination comprising at least one of the foregoing activation signals.

13. The method of claim 6, wherein the active material is a shape memory alloy, a ferromagnetic shape memory alloy, a shape memory polymer, a magnetorheological fluid, an electroactive polymer, a magnetorheological elastomer, an electrorheological fluid, a piezoelectric material, or a combination comprising at least one of the foregoing active materials.

14. The method of claim 6, wherein the change in at least one property is a dimension, a shape, a shear force, a shape orientation, a flexural modulus, a phase of matter, or a combination comprising one or more of the foregoing properties.

15. The method of claim 6, wherein the change in the at least one property is effective to vibrate, displace, and/or change the stiffness of selected portions of the vehicle surface.

16. The method of claim 15, wherein vibrating, displacing, or changing the stiffness of the selected portions provides a directional indication of a condition.

17. The method of claim 6, further comprising increasing a vibration frequency, a vibration amplitude, the size of the area of vibration or a combination of the vibration frequency, amplitude, and area in response to an increase in probability of an occurrence of a sensed condition.