Eccentric rotating mass actuator optimization for haptic effects

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.

1 - 20 . (canceled) 
     
     
         21 . A method of providing a haptic effect on a device including an Eccentric Rotating Mass (ERM) actuator using varying voltages to optimize the haptic effect, the method comprising:
 applying an overdrive voltage to the ERM actuator for an overdrive rise time;   applying a rated voltage to the ERM actuator for a remaining time after the overdrive rise time, wherein the rated voltage is less than the overdrive voltage; and   applying a reverse overdrive voltage to the ERM actuator for an overdrive brake time after the remaining time to brake the ERM actuator.   
     
     
         22 . The method of  claim 21 , wherein the overdrive voltage is applied for the overdrive rise time to reach a target speed of the ERM actuator. 
     
     
         23 . The method of  claim 22 , wherein the rated voltage is applied for the remaining time to maintain the target speed. 
     
     
         24 . The method of  claim 21 , wherein the overdrive rise time is shorter than a rated rise time that indicates a time duration for applying the rated voltage to the ERM actuator to reach a target speed of the ERM. 
     
     
         25 . The method of  claim 21 , wherein the overdrive brake time is shorter than a rated brake time that indicates a time duration for applying a reverse rated voltage to the ERM actuator to reduce the speed of the ERM actuator from a target speed to zero, the reverse rated voltage being a reverse voltage of the rated voltage. 
     
     
         26 . The method of  claim 21 , further comprising:
 operating the ERM actuator to determine at least one of a back electromotive force (EMF) of the ERM actuator, an acceleration of the ERM actuator, or a vibration level of the device,   wherein at least one of the overdrive rise time, the remaining time, or the overdrive brake time is based on at least one of the back EMF, the acceleration, or the vibration level.   
     
     
         27 . The method of  claim 26 , further comprising:
 determining the overdrive rise time of the ERM actuator based on the overdrive voltage and at least one of the back EMF, the acceleration, or the vibration level.   
     
     
         28 . The method of  claim 26 , further comprising:
 determining the overdrive brake time of the ERM actuator based on the reverse overdrive voltage and at least one of the back EMF, the acceleration, or the vibration level.   
     
     
         29 . The method of  claim 26 , wherein determining the back EMF of the ERM actuator includes measuring an output voltage across the ERM actuator. 
     
     
         30 . The method of  claim 21 , further comprising:
 determining an instantaneous speed of the ERM actuator during operation of the device; and   adjusting at least one of the overdrive voltage, the rated voltage, or the reverse overdrive voltage based on the instantaneous speed.   
     
     
         31 . The method of  claim 21 , further comprising:
 receiving an instruction to apply the rated voltage to the ERM actuator to generate the haptic effect; and   converting the instruction received to apply the overdrive voltage for the overdrive rise time, the rated voltage for the remaining time, and the reverse overdrive voltage for the overdrive brake time.   
     
     
         32 . A haptically enabled system for providing a haptic effect using varying voltages to optimize the haptic effect, the system comprising:
 an Eccentric Rotating Mass (ERM) actuator; and   a controller coupled to the ERM actuator, the controller configured to
 apply an overdrive voltage to the ERM actuator for an overdrive rise time of, 
 apply a rated voltage to the ERM actuator for a remaining time after the overdrive rise time, wherein the rated voltage is less than the overdrive voltage, and 
 apply a reverse overdrive voltage to the ERM actuator for an overdrive brake time after the remaining time to brake the ERM actuator. 
   
     
     
         33 . The haptically enabled system of  claim 32 , wherein the overdrive voltage is applied for the overdrive rise time to reach a target speed of the ERM actuator. 
     
     
         34 . The haptically enabled system of  claim 33 , wherein the rated voltage is applied for the remaining time to maintain the target speed. 
     
     
         35 . The haptically enabled system of  claim 32 , wherein the overdrive rise time is shorter than a rated rise time that indicates a time duration for applying the rated voltage to the ERM actuator to reach a target speed of the ERM. 
     
     
         36 . The haptically enabled system of  claim 32 , wherein the overdrive brake time is shorter than a rated brake time that indicates a time duration for applying a reverse rated voltage to the ERM actuator to reduce the speed of the ERM actuator from a target speed to zero, the reverse rated voltage being a reverse voltage of the rated voltage. 
     
     
         37 . The haptically enabled system of  claim 32 , wherein the controller is further configured to operate the ERM actuator to determine at least one of a back electromotive force (EMF) of the ERM actuator, an acceleration of the ERM actuator, or a vibration level of the device,
 wherein at least one of the overdrive rise time, the remaining time, or the overdrive brake time is based on at least one of the back EMF, the acceleration, or the vibration level.   
     
     
         38 . The haptically enabled system of  claim 37 , wherein the controller is further configured to determine the overdrive rise time of the ERM actuator based on the overdrive voltage and at least one of the back EMF, the acceleration, or the vibration level. 
     
     
         39 . The haptically enabled system of  claim 37 , wherein the controller is further configured to determine the overdrive brake time of the ERM actuator based on the reverse overdrive voltage and at least one of the back EMF, the acceleration, or the vibration level. 
     
     
         40 . The haptically enabled system of  claim 37 , wherein the controller is configured to determine the back EMF of the ERM actuator by measuring an output voltage across the ERM actuator. 
     
     
         41 . The haptically enabled system of  claim 32 , wherein the controller is further configured to
 determine an instantaneous speed of the ERM actuator during operation of the device, and   adjust at least one of the overdrive voltage, the rated voltage, or the reverse overdrive voltage based on the instantaneous speed.   
     
     
         42 . The haptically enabled system of  claim 32 , wherein the controller is further configured to
 receive an instruction to apply the rated voltage to the ERM actuator to generate the haptic effect, and   convert the instruction received to apply the overdrive voltage for the overdrive rise time, the rated voltage for the remaining time of the haptic effect duration, and the reverse overdrive voltage for the overdrive brake time.