Eccentric rotating mass actuator optimization for haptic effects

Patent metadata

Field	Value
Publication number	US-10101815-B2
Application number	US-201815884649-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Feb 1, 2012
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A system that generates a haptic effect using an Eccentric Rotating Mass (“ERM”) actuator determines a back electromotive force (“EMF”) of the ERM actuator during operation of the device and receives a haptic effect signal including one or more parameters, where one of the parameters is a voltage amplitude level as a function of time. Based on the determined back EMF, the system determines if the ERM actuator is spinning and varies the voltage amplitude level based on the back EMF to generate a varied haptic effect signal, where the varying includes, when the ERM actuator is determined to be spinning, reducing the voltage amplitude level compared to when the ERM actuator is determined to not be spinning. The system then applies the varied haptic effect signal to the ERM actuator.

First claim

What is claimed is:

1. A method of generating a haptic effect on a device comprising an Eccentric Rotating Mass (ERM) actuator, the method comprising:
determining an instantaneous speed of the ERM actuator during operation of the device;
receiving a haptic effect signal comprising one or more parameters, wherein the parameters define a time varying speed profile; and
applying the haptic effect signal to the ERM actuator to generate the haptic effect, the applying comprising adjusting a voltage across the ERM actuator based on the time varying speed profile and the instantaneous speed.

2. The method of claim 1 , wherein the determining the instantaneous speed of the ERM actuator comprises determining a back electromotive force (EMF) of the ERM actuator during operation of the device.

3. The method of claim 2 , wherein the determining the back EMF of the ERM actuator during operation of the device comprises measuring an output voltage across the ERM actuator.

4. The method of claim 2 , further comprising:
determining a rise time of the ERM actuator using the back EMF; and
adjusting the voltage based at least on the rise time.

5. The method of claim 4 , further comprising:
determining a brake time of the ERM actuator using the back EMF; and
varying the voltage based at least on the brake time.

6. The method of claim 1 , wherein the time varying speed profile comprises an overdrive voltage.

7. The method of claim 1 , wherein the device comprises a handheld device.

8. A non-transitory computer readable medium having instructions stored thereon that, when executed by a processor, cause the processor to generate a haptic effect on a device comprising an Eccentric Rotating Mass (ERM) actuator, the processor:
determining an instantaneous speed of the ERM actuator during operation of the device;
receiving a haptic effect signal comprising one or more parameters, wherein the parameters define a time varying speed profile; and
applying the haptic effect signal to the ERM actuator to generate the haptic effect, the applying comprising adjusting a voltage across the ERM actuator based on the time varying speed profile and the instantaneous speed.

9. The non-transitory computer readable medium of claim 8 , wherein the determining the instantaneous speed of the ERM actuator comprises determining a back electromotive force (EMF) of the ERM actuator during operation of the device.

10. The non-transitory computer readable medium of claim 9 , wherein the determining the back EMF of the ERM actuator during operation of the device comprises measuring an output voltage across the ERM actuator.

11. The non-transitory computer readable medium of claim 9 , further comprising:
determining a rise time of the ERM actuator using the back EMF; and
adjusting the voltage based at least on the rise time.

12. The non-transitory computer readable medium of claim 11 , further comprising:
determining a brake time of the ERM actuator using the back EMF; and
varying the voltage based at least on the brake time.

13. The non-transitory computer readable medium of claim 9 , wherein the time varying speed profile comprises an overdrive voltage.

14. The non-transitory computer readable medium of claim 9 , wherein the device comprises a handheld device.

15. A haptically enabled system comprising:
an Eccentric Rotating Mass (ERM) actuator; and
a controller coupled to the ERM actuator, the controller configured to determine an instantaneous speed of the ERM actuator during operation of the device and receive a haptic effect signal comprising one or more parameters, wherein the parameters define a time varying speed profile;
the controller further configured to apply the haptic effect signal to the ERM actuator to generate the haptic effect by adjusting a voltage across the ERM actuator based on the time varying speed profile and the instantaneous speed.

16. The haptically enabled system of claim 15 , wherein the determine the instantaneous speed of the ERM actuator comprises determining a back electromotive force (EMF) of the ERM actuator during operation of the system.

17. The haptically enabled system of claim 16 , wherein the determining the back EMF of the ERM actuator during operation of the system comprises measuring an output voltage across the ERM actuator.

18. The haptically enabled system of claim 16 , the controller further configured to determine a rise time of the ERM actuator using the back EMF and adjust the voltage based at least on the rise time.

19. The haptically enabled system of claim 16 , the controller further configured to determine a brake time of the ERM actuator using the back EMF and vary the voltage based at least on the brake time.

20. The haptically enabled system of claim 15 , wherein the time varying speed profile comprises an overdrive voltage.

Assignees

• Immersion Corp

Inventors

• Lacroix Robert A
• Greenish Michael A
• Ramsay Erin B

Classifications

• H04M19/047

  Vibrating means for incoming calls · CPC title

• G08B6/00

  Tactile signalling systems, e.g. tactile personal calling systems · CPC title

• G06F3/016 Primary

  Input arrangements with force or tactile feedback as computer generated output to the user · CPC title

• B06B1/00

  Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency · CPC title