PATENT DOCUMENT

Publication Number: US-8552859-B2
Application Number: US-57132609-A
Country: US
Kind Code: B2

Title: Self adapting alert device

Abstract:
Methods and apparatuses are disclosed that allow an electronic device to autonomously adapt one or more user alerts to the current operating environment of the electronic device. For example, some embodiments may include a method comprising providing a plurality of alert devices in an electronic device, determining an operating environment of the electronic device using a sensor of the electronic device, and actuating at least one of the plurality of alert devices that corresponds to the determined operating environment.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a storage unit; 
 a motor controller; 
 a motor coupled to the motor controller, wherein the motor is configured to provide a user alert and wherein a reference value stored in the storage unit is autonomously varied to achieve a target frequency of the motor; and 
 an accelerometer, wherein values from the accelerometer are iteratively used by the electronic device to adjust the stored reference value. 
 
     
     
       2. The electronic device of  claim 1 , wherein the electronic device is a phone and the adjustment of the stored reference value occurs within an integer number of rings of the phone. 
     
     
       3. The electronic device of  claim 1 , wherein an initial reference value is stored in the storage unit that corresponds to an operating environment of the electronic device. 
     
     
       4. The electronic device of  claim 3 , further comprising a sensor, wherein the operating environment is determined based upon a measurement from the sensor. 
     
     
       5. The electronic device of  claim 1 , wherein the target frequency is determined based upon the motor controller iteratively changing a control signal to the motor. 
     
     
       6. The electronic device of  claim 1 , further comprising a plurality of motors capable of being operated concurrently so as to achieve the target frequency. 
     
     
       7. An electronic device, comprising:
 a storage unit; 
 a motor controller; 
 a motor coupled to the motor controller, wherein the motor is configured to provide a user alert and wherein a reference value stored in the storage unit is autonomously varied to achieve a tar et frequency of the motor, wherein an initial reference value is stored in the storage unit that corresponds to an operating environment of the electronic device; and 
 an error detector, wherein the operating environment is determined based upon minimizing an error signal from the error detector. 
 
     
     
       8. An electronic device, wherein the electronic device is configured to operate in an operating environment, comprising:
 a vibration motor configured to provide a user alert; 
 a control system configured to control the vibration motor to achieve a target frequency that is customized to the operating environment, wherein the target frequency comprises a maximum resonance frequency; and an accelerometer, wherein the control system is configured to control the vibration motor based on at least one measurement of the accelerometer. 
 
     
     
       9. The electronic device defined in  claim 8 , wherein the control system comprises a storage unit configured to store an initial reference value corresponding to an initial frequency of the electronic device in the current operating environment. 
     
     
       10. The electronic device defined in  claim 8 , wherein the target frequency comprises a maximum resonance frequency and wherein the control system is configured to control the vibration motor based on a feedback measurement from the accelerometer. 
     
     
       11. The electronic device defined in  claim 8 , wherein the electronic device comprises a cellular telephone, and wherein the control system is configured to achieve the target frequency within one ring of the cellular telephone. 
     
     
       12. The electronic device defined in  claim 8 , further comprising a storage unit configured to store a target reference value corresponding to the target frequency after the target frequency is achieved. 
     
     
       13. An electronic device, wherein the electronic device is configured to operate in an operating environment, comprising:
 a vibration motor configured to provide a user alert; 
 a control system configured to control the vibration motor to achieve a target frequency that is customized to the operating environment, wherein the target frequency comprises a maximum resonance frequency, wherein the control system comprises a storage unit configured to store an initial reference value corresponding to an initial frequency of the electronic device in the current operating environment; and a sensor configured to make a measurement of the current operating environment, wherein the initial frequency is based on the measurement from the sensor. 
 
     
     
       14. The electronic device defined in  claim 13 , wherein the sensor comprises an ambient light sensor. 
     
     
       15. The electronic device defined in  claim 13 , wherein the sensor comprises an accelerometer. 
     
     
       16. An electronic device, wherein the electronic device is configured to operate in an operating environment, comprising:
 a vibration motor configured to provide a user alert; 
 a control system configured to control the vibration motor to achieve a target frequency that is customized to the operating environment; and 
 an accelerometer, wherein the control system comprises an error detector configured to compare a measurement of the accelerometer to a reference value corresponding to a current frequency of the vibration motor. 
 
     
     
       17. An electronic device, comprising:
 a storage unit; 
 an error detector; 
 a sensor; 
 a motor controller; and 
 a motor coupled to the motor controller, wherein the motor is configured to provide a user alert, wherein the sensor is configured to make a measurement of the motor, wherein a reference value that corresponds to a current frequency of the motor is stored in the storage unit, wherein the error detector is configured to compare the measurement of the motor with the reference value, and wherein the reference value is autonomously varied to achieve a target frequency of the motor.

Description:
BACKGROUND OF THE INVENTION 
     I. Technical Field 
     The present invention relates generally to alert devices in electronic systems, and more particularly to a self adapting alert device. 
     II. Background Discussion 
     Electronic devices are ubiquitous in society and can be found in everything from wristwatches to computers. Many of these electronic devices are portable and also include the ability to obtain a user&#39;s attention through the use of an alert device. For example portable electronic devices like cellular phones and watches contain alert devices such as vibrating motors, speakers, and/or lights to attract the user&#39;s attention. Because of their portable nature, many of these portable electronic devices are made as small as possible by miniaturizing the components therein. As part of this miniaturization effort, the alert devices in the electronic devices are often made as small as possible in order to conserve space. However, these miniaturized alert devices can be problematic for several reasons. 
     First, these miniaturized alert devices may be inadequate to obtain the user&#39;s attention in a variety of different situations. For example, if the user of a cell phone is in an environment where there is a great deal of ambient noise, such as a concert or live sporting event, then the user may be unable to see a visual alert from a miniaturized light on the phone, hear an auditory alert from a miniaturized speaker in the phone and/or unable to detect vibration coming from the phone&#39;s miniaturized vibration motor. 
     Additionally, because of electronic devices often contain slight variations in the way they were manufactured, the actual response of the alert device within the electronic device may vary between electronic devices. In other words, slight variations in the actual manufacturing of an electronic device may cause the electronic device to react differently to the same force driving the alert device. For example, the vibration frequency may vary between phones of the same make and model because of manufacturing tolerance, and therefore, the same amount of vibration from a vibrating motor may unintentionally produce different levels of user alerts. 
     Thus, methods and systems that adaptively adjust the alert devices within electronic devices to overcome one or more of these problems are desirable. 
     SUMMARY 
     Methods and apparatuses are disclosed that allow an electronic device to autonomously adapt one or more user alerts to the current operating environment of the electronic device. For example, some embodiments may include a method comprising providing a plurality of alert devices in an electronic device, determining an operating environment of the electronic device using a sensor of the electronic device, and actuating at least one of the plurality of alert devices that corresponds to the determined operating environment. 
     Other embodiments may include an electronic device that autonomously adjusts a user alert, the electronic device comprising a storage unit, an error detector couple to the storage unit, a sensor coupled to the error detector, a motor controller coupled to the error detector, and a motor coupled to the motor controller, wherein a reference value stored in the storage unit is varied to achieve a target frequency of the electronic device. 
     Still other embodiments may include a method of adjusting user alerts in an electronic device, the method comprising determining a current operating environment from a sensor of the electronic device, storing an initial reference value corresponding to an initial target frequency of the electronic device in the current operating environment, and in the event that the user alert is to be optimized, then the method further comprises modifying the initial reference value and storing measurements from the sensor 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an electronic device capable of self adapting one or more of its alert devices to obtain the attention of a user in different environments. 
         FIG. 2  illustrates one operating environment for the electronic device. 
         FIG. 3  illustrates an alternate operating environment for the electronic device. 
         FIG. 4  illustrates an alternate embodiment of an electronic device that includes a plurality of motors. 
         FIG. 5  illustrates a block diagram of an electronic device capable of self adapting one or more of its alert devices to obtain the attention of a user in different environments. 
         FIG. 6  illustrates a feedback and control system that may allow the electronic device to achieve a target frequency that is customized to the current operating environment. 
         FIG. 7  illustrates a control signal that may be generated by the feedback and control system shown in  FIG. 6 . 
         FIG. 8  illustrates operations for determining a reference value corresponding to a maximum target frequency corresponding to a current operating environment of the electronic device. 
     
    
    
     The use of the same reference numerals in different drawings indicates similar or identical items. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of electronic devices are disclosed that allow the electronic device to autonomously observe its current operating condition and adjust its user alerts accordingly. The electronic device may determine its current operating environment (e.g., indoors, outdoors, contained in a purse or bag, etc.) through a series of sensor measurements. Based upon these sensor measurements the electronic device may both select and/or optimize the user alerts to suit the current operating environment. For example, some embodiments may utilize the sensor measurements to determine which of the possible user alerts is best suited to the current operating environment of the electronic device—e.g., if the current operating environment is indoors in a conference room, then the auditory alerts may not be the most suitable user alert in this operating environment. Other embodiments may utilize the sensor measurements to optimize the user alerts. For example some embodiments may include operating a motor to cause the electronic device to vibrate and obtain the user&#39;s attention through tactile sensation. In these embodiments, the sensor measurements may be utilized to actively tune the motor such that the electronic device achieves a target frequency that best corresponds to the current operating environment of the electronic device. 
     Although one or more of the embodiments disclosed herein may be described in detail with reference to a particular electronic device, the embodiments disclosed should not be interpreted or otherwise used as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application. For example, while embodiments disclosed herein may focus on portable electronic devices such as cell phones, it should be appreciated that the concepts disclosed herein equally apply to other portable electronic devices such as the IPOD brand portable music player from Apple Inc. In addition, it should be appreciated that the concepts disclosed herein may equally apply to non-portable electronic devices, such as computer equipment (keyboard, mice, etc.) and/or gaming devices (e.g., gaming controllers). Furthermore, while embodiments disclosed herein may focus on optimizing the vibration output of the electronic devices, the concepts disclosed herein equally apply to other forms of user alerts, such as sound devices and/or light devices. Accordingly, the discussion of any embodiment is meant only to be exemplary and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these embodiments. 
       FIG. 1  illustrates an electronic device  100  capable of autonomously adjusting one or more of its alert devices to obtain the attention of a user of the electronic device  100  in different environments. For the sake of discussion, the electronic device  100  is shown in  FIG. 1  as a cell phone, such as an IPHONE brand cell phone from Apple Inc. The electronic device  100  may include one or more alert devices capable of obtaining the attention of the user of the electronic device  100 , including a vibration motor  102 , a light source  104 , and/or a speaker  106 .  FIG. 1  also shows that these alert devices  102 ,  104 , and  106  may be coupled to one or more sensors  108  and  110  located within the electronic device  100 . As will be discussed in greater detail below, the sensors  108  and  110  in the electronic device  100  may include devices that measure indications about the environment in which the electronic device  100  is operating. These measurements may include the movement, proximity to the user, location, whether the user is holding the electronic device  100 , ambient light levels, and/or ambient noise levels experienced by the electronic device  100  to name just a few. 
     Based these measurements, the electronic device  100  may autonomously decide the most effective way to obtain the user&#39;s attention in that particular environment.  FIGS. 2 and 3  illustrate two distinct operating environments for the electronic device  100 , where the alert used to obtain the user&#39;s attention may vary between these two operating environments. Referring first to the operating environment shown in  FIG. 2 , the electronic device  100  may be lying flat on a table  200  such as may be the case when the user is in a classroom or meeting. If the sensors  108  and  110  are implemented as an accelerometer and microphone respectively, then the electronic device  100  may detect that it is in a classroom or meeting by the sensors  108  and  110  reporting no movement from the accelerometer and/or a relatively low ambient noise level from the microphone. Upon detecting that it is operating in this environment, the electronic device  100  may silence any audible alerts to the user, such as when there is an incoming phone call. 
     Conversely,  FIG. 3  illustrates a user  300  carrying the electronic device  100  in a purse  305  where it may be jostled around. If the sensors  108  and  110  are implemented as an accelerometer and an ambient light sensor (ALS) respectively, then the electronic device  100  in this operating environment may detect that it is in a confined space that is dark by the ALS reporting a relatively low ambient light level and that the electronic device  100  is being moved around by the accelerometer reporting movement. This operating environment may require louder user alerts than the situation shown in  FIG. 2 , for example, the strength of user alerts, both auditory and vibrations, may be increased in these situations. 
     Referring again to the electronic device  100  shown in  FIG. 1 , the motor  102  shown includes an eccentric weight  112  coupled to a motor body  114  via a shaft  116 . When an electric signal, such as a voltage signal, is applied to the motor body  114 , the shaft  116  begins to rotate causing the weight  112  to move in a substantially orbital path. Because the weight  112  is uneven, as the weight  112  begins to be rotated in this substantially orbital path, the motor  102  begins to vibrate, and as a result, the motor  102  causes the entire electronic device  100  to vibrate. When the electronic device  100  is deployed in different operating environments, the maximum target frequency of the electronic device  100 , or frequency at which the entire electronic device  100  experiences its maximum vibration, may vary between different operating environments. For example, comparing the two operating environments shown in  FIGS. 2 and 3 , the electronic device  100  making physical contact with the table  200  will have a different target frequency than the same electronic device  100  being jostled around in the purse  305 . By monitoring the sensors  108  and  110  based upon these measured parameters, the target frequency of the electronic device in these different operating environments may be determined. Furthermore, by actively adjusting the vibration of the motor  102  based upon these measured parameters, the electronic device  100  may be adjusted to achieve this target frequency in different operating environments. That is, the electronic device  100  may actively “tune” itself to its target frequency using measurements obtained from the sensors  108  and  110  and adjusting the motor  102 . In the embodiments where the electronic device  100  is a phone, this active adjustment may occur within the period of a single ring of the phone, such that the phone is ringing at its target frequency before the end of the first ring of an incoming call to maximize the chances of obtaining the user&#39;s attention. Similarly, when the electronic device  100  is a multi-function device that includes the ability to check electronic mail, this active adjustment may occur within the period of time it takes to notify the user of a new mail event. 
       FIG. 4  illustrates an alternate embodiment of an electronic device  400 , which includes a plurality of motors  402 - 408  coupled to the sensors  409  and  410 . As shown, in this embodiment, the plurality of sensors  402 - 408  may be in different locations within the electronic device  400  so as to vibrate different portions of the electronic device  400 . In this embodiment, the target frequency of the electronic device  400  may be achieved by actuating the plurality of motors  402 - 408  in different patterns, where the pattern of actuating the plurality of motors  402 - 408  varies according to the different operating environments of the electronic device  400 . For example, if the electronic device  400  is located within the purse  305  as shown in  FIG. 3  and the sensors  409  and  410  indicate that one end  412  of the electronic device is touching the bottom of the purse  305  and the other end  414  is not touching the bottom of the purse  305 , then the motors  402  and  408  may be actuated to achieve the target frequency of the electronic device  400  while the other motors in the plurality  404  and  406  are not actuated. Thus, the electronic device  400  may be tuned to its target frequency in different environments by selectively actuating one or more of the motors within the plurality  402 - 408 . 
       FIG. 5  illustrates a block diagram of an electronic device  500  that may be employed in the embodiments shown above. As shown, the electronic device  500  includes a plurality of sensors  502 - 512  that couple to a processor  516 . These sensors  502 - 512  may be used alone or in combination to determine the current operating environment of the electronic device  500 . The microprocessor  516  may be further coupled to one or more alert devices  518 - 522 . 
     As was mentioned above, the ALS  502  senses the ambient light of the environment that the electronic device  500  is in and reports this information to the processor  516 . When the processor  516  receives this ambient light information, it can modify alert operations of the electronic device  500  accordingly. Thus, in the embodiments where the electronic device  500  is a phone, if ambient light measurements indicate that the level of ambient light is relatively high, then alert mechanisms other than the light  518  may be used to obtain the user&#39;s attention, such as the motor  520  and/or speaker  522 , because the light  518  may be unperceivable to the user because the ambient light conditions. As was mentioned above, the information from the sensors may be combined such that the ambient light measurement from the ALS  502  may be used in conjunction with other measurements, such as ambient noise level, to detect a current operating environment of the electronic device  500 . 
     The microphone  504  may sample the ambient noise level of the environment that the electronic device  500  is in and report this information to the processor  516 . Thus, the microphone  504  may indicate that the ambient noise level is too high for the speaker  522  to obtain the user&#39;s attention, and therefore, alert mechanisms other than the speaker  522  may be used to obtain the user&#39;s attention, such as the motor  520  and/or the light  518 . In the embodiments where the electronic device  500  is a phone, then the microphone  504  may be the microphone used by the user of the electronic device  500  when using the phone. 
     The infrared (IR) detector  506  may detect a user&#39;s proximity to the electronic device  500  and report this information to the processor  516 . In some embodiments, the IR detector  506  may include one or more solid state sensors, such as pyroelectric materials, which detect heat from a user&#39;s body being near the electronic device  500 . In other embodiments, the IR sensor may include a light emitting diode (LED) that emits infrared light which bounces off a user in close proximity to the electronic device  500  and is detected by an IR sensor that is based upon a charge coupled device (CCD), where the CCD may detect reflected IR light emitted by the LEDs. In still other embodiments, a photoresistor may be used in place of or in conjunction with the CCD. Regardless of the actual implementation of the IR detector  506 , the IR detector  506  may convey its signal to the processor  516  as an indication of a user&#39;s presence near the electronic device  500 , and this indication may be used in conjunction with one or more of the other sensors to determine the current operating environment of the electronic device  500 . 
     The camera  508  may capture certain visual queues for use in determining the operating environment of the electronic device  500 . In some embodiments, the camera  508  may be integrated within the ALS  502 . In other embodiments, the camera  508  may be located on a separate portion of the electronic device  500  and may be used to confirm measurements from one of the other sensors, such as the ALS  502 . For example, in the event that the electronic device  500  is implemented as a phone and the ALS  502  is positioned on one side of the phone, such as the face side that the user positions against their head when using the phone, and the camera  508  is positioned on the opposite side of the electronic device  500  as the ALS  502 , then the camera  508  may be used to confirm measurements indicating that the phone is in a certain operating environment. 
     Furthermore, in some embodiments, measurements from the camera  508  may be used to provide additional information regarding the operating environment of the electronic device  500 . For example, if the electronic device  500  is implemented as the phone shown in  FIG. 2 , where the phone is lying face down, and the ALS  502  is located on the face of the phone while the camera  508  is located on the opposite side of the phone, then by the ALS  502  indicating that it is receiving substantially no light while the camera  508  indicates that it is receiving light, then may indicate that the phone is lying face down on the table. 
     The accelerometer  510  may indicate the general orientation of the electronic device  500 . In some embodiments, this indication may be through measurement of a damped mass on an integrated circuit, such as a micro electro-mechanical system (MEMS) For example, the accelerometer  510  may include one or more “in-plane” MEMS accelerometers, which are sensitive in a plane that is parallel to the sensing element (such as the damped mass), and therefore multiple dimension (such as two and three dimension accelerometers) may be formed by combining two or more in-plane accelerometers orthogonal to each other. Other embodiments may utilize out-of-plane MEMS accelerometers, which are sensitive to positional movements in a direction that is in a plane that is perpendicular to the sensing element (sometimes referred to as Coriolis movement). Some embodiments may combine one or more in-plane MEMS sensors with one or more out-of-plane MEMS sensors to form the accelerometer  510 . As mentioned above, the accelerometer  510  may be used to determine orientation of the electronic device  500  (such as face up, face down, tilted, etc.) and/or whether the electronic device  500  is being jostled about by the user (such as inside of the purse  305  shown in  FIG. 3 ). By providing the measurements from the accelerometer  510  to the processor  516  in addition to measurements from other sensors, the processor  516  may combine the measurements and confirm of the other sensors. For example, if the combination of the ALS  502  and the camera  508  indicate that the electronic device  500  is lying face down (as discussed above with regard to  FIG. 2 ), then the processor  516  may utilize measurements from the accelerometer  510  to confirm this positional information. 
     The global positioning system (GPS) sensor  511  may indicate the position of the electronic device  500  with respect to the latitude and longitude coordinates of the Earth as determined by signals from a plurality of geosynchronous satellites orbiting the Earth. Since the GPS sensor  511  may be unable to receive satellite signals while indoors, the GPS sensor  511  may be used to detect whether the electronic device  500  is indoors or outdoors, and the processor  516  may adjust the alerts accordingly. 
     The capacitive screen sensor  512  may detect whether the user is making contact with the electronic device  500 , and/or how much contact the user is making with the electronic device. For example, if the user is holding the electronic device  500  in their pocket, then the capacitive screen sensor  512  may indicate a certain capacitance level associated with the user&#39;s body. On the other hand, in the event that the electronic device  500  is located the purse  305  as shown in  FIG. 3 , then the capacitive screen sensor  512  may indicate a different capacitance associated with the fabric of the purse  305 . Also, when the capacitive screen sensor  512  senses substantially no capacitance value, then the electronic device  500  may be on a table  200  as shown in  FIG. 2 . 
     Table 1 illustrates how values from the capacitive screen sensor  512  may be confirmed by the other sensors, such as the ALS  502 . For example, when the ALS indicates that the ambient light level is low, such as when the phone may be in a pocket or in the purse  305 , then the capacitive screen sensor  512  may be consulted by the processor  516  to determine if the capacitance value corresponds to human versus non-human capacitance so that the processor  516  may determine the operating environment an adjust the user alerts accordingly. Similarly, in the event that the capacitive screen sensor  512  indicates that substantially no capacitance is measured, then the ALS  502  may be consulted to determine if the light level is high indicating that the operating environment is on the table  200  in a bright room or, if the light level is low, indicating that the operating environment is on the table  200  in a dark room, such as a night stand. The processor  516  then may adjust the alerts accordingly, such as by silencing alerts from the speaker  522  in the event that the electronic device  500  is on a night stand. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                   
                   
                 ALS 502 
               
            
           
           
               
               
               
               
            
               
                   
                   
                 High 
                 Low 
               
               
                   
               
               
                 Capacitive Screen 
                 Full screen, 
                   
                 In pocket 
               
               
                 Sensor 
                 human 
                   
                   
               
               
                 512 
                 Full screen, 
                   
                 In purse 
               
               
                   
                 non-human 
                   
                   
               
               
                   
                 Nothing 
                 On conference table 
                 On night-stand 
               
               
                   
               
            
           
         
       
     
     Referring still to  FIG. 5 , each of the sensors  502 - 512  may be used by the processor to optimize the performance of the light  518 , the motor  520  and/or the speaker  522  to the operating environment of the electronic device  500 .  FIG. 6  depicts a block diagram of an illustrative feedback and control system  600  that may be implemented by the electronic device  500  to control the motor  520  such that its movement allows the electronic device  500  to achieve a target frequency that is customized to the operating environment. As shown in block  605  of  FIG. 6 , the control system  600  may include a storage unit  605  that includes a reference value that is reported to other items in the control system  600 . For the sake of discussion, this disclosure will discuss the reference value as based upon an accelerometer measurement, although it should be appreciated that this measurement may be based upon a wide variety of sensors, such as one or more of the sensors  502 - 512 . Also, the reference value in the storage unit  605  may be a combination of measurements from more than one of the sensors  502 - 512 . 
     The control system  600  may include an error detector  610  coupled to the storage unit  605  and the accelerometer  510 . The accelerometer  510  may report its measurements to the error detector  610  in the same form as the reference measurements stored in the storage unit  605 . As was mentioned above, measurements from the accelerometer  510  may represent movement of the electronic device  500  in the current operating environment of the electronic device  500 , and as a result, the measurements from the accelerometer  510  may be used to measure the target frequency of the electronic device  500 . During operation, the error detector  610  may compare the reference value stored in the storage unit  605  with the current measurement from the accelerometer  510  and output an error signal E s . 
     The error detector  610  may couple to a motor controller  615  and thereby provide the error signal E s  to the controller  615 . The controller  615  may utilize the error signal E s  in controlling the input signals to the motor  520 , such as by generating a control signal that is proportional to the difference between the reference value stored in the storage unit  605  and the accelerometer  510 . As mentioned above, the electrical signal applied to the motor  520  may be a voltage, and therefore, the control signal generated by the motor controller  615  may vary one or more aspects of the voltage that is applied to the motor  520 . For example, control of the motor  520  may be accomplished by varying the amplitude, frequency, and/or duty cycle of the voltage that is applied to the motor  520 . 
     In some embodiments, the motor  520  may be controlled using a pulse width modulated (PWM) signal. This PWM signal may allow more robust control of the motor  520  than conventional methods, such as an on/off control. In these embodiments, the PWM signal may be used to initially overdrive the motor  520  to reduce the rise time or ‘spin up’ for the motor  520  thereby producing a sharper turn on of the motor  520 . Similarly, in these embodiments, the PWM signal may be used to underdrive the motor  520 , or inductively brake the motor  520 , so as to achieve a sharper turn off of the motor  520 . This sharper on and off action of the motor  520  may result in more noticeable tactile sensations to a user when using the motor  520  as an alert device. 
       FIG. 7  illustrates varying the frequency of the control signal where the frequency varies with respect to time. Note that the varying frequency may be monotonically increasing during each cycle of the control system  600  (section  705 ), unchanged during each cycle of the control system  600  (section  708 ), monotonically decreasing during each iteration of the control system  600  (section  710 ), or be dithered between two or more values during each cycle of the control system  600  (section  715 ). 
     Referring back to the control system  600  shown in  FIG. 6  in conjunction with the electronic device  500  shown in  FIG. 5 , in some embodiments, the storage unit  605 , error detector  610 , and motor controller  615  may be incorporated into the microprocessor  516 . Thus, during operation, the microprocessor  516  may sample values from the accelerometer  510  (which represents movement of the electronic device  500  within its current operating environment) and actively control the motor  520  such that the error signal E s  is minimized and the reference value stored in the storage unit  605  is achieved. The reference value that is stored in the storage unit  605  may be modified autonomously by the electronic device so that the control system  600  is actively tuning itself to this changing reference value. By changing the reference value stored in the storage unit  605 , and tracking the measurements from the accelerometer  510  in response to this varying reference value, the target frequency of the electronic device  500  in its current operating environment may be calculated. For example, as the reference value is varied, the reference value that causes the electronic device  500  to achieve maximum resonance in the current operating environment (as measured by the accelerometer  510 ), may be stored in the storage unit  605 . 
       FIG. 8  illustrates operations  800  for determining a reference value corresponding to a target frequency of the electronic device. The target frequency of the electronic device may be a resonant frequency of the electronic device  500  in its current operating environment, or alternatively, may be a frequency of the device that maximizes a user&#39;s perception of the alert. It should be appreciated that the operations shown in  FIG. 8  are illustrative, and that other operations for determining a reference value may be performed in other embodiments. The operations  800  are discussed herein in the context of the electronic device  500  being a phone that is receiving an incoming call, however, the operations  800  may be applied in other contexts, such as in the context of a personal digital assistant (PDA) alerting a user to an appointment for example. 
     Referring now to  FIG. 8 , block  805  shows the electronic device  500  receiving an incoming call. Generally, the duration of a single ring for an incoming call may be five seconds and the phone may ring for a total of five rings before being transferred to voicemail, or twenty five seconds. In some embodiments, the operations  800  may be triggered when the electronic device  500  beings to ring on the first ring and complete within this first ring, and therefore the block  805  occur on first ring. In other embodiments, the operations  800  may occur on a subsequent ring and complete within that subsequent, and therefore the block  805  may be a subsequent ring. In still other embodiments, the operations  800  may begin at the beginning of the first ring and complete before the phone transfers the call to voicemail. 
     Once the electronic device  500  receives an incoming call, the electronic device  500  will detect the current system state per block  810 . For example, the microprocessor  516  may observe the values of one or more of the sensors  502 - 512  to determine their values, and as was discussed above, based upon one or more of these measurements, the electronic device  500  may predict the operating environment of the electronic device (e.g., on a table as shown in  FIG. 2  versus in the purse  305  as shown in  FIG. 3 ). 
     Next, in block  815 , the initial reference value may be loaded into the storage unit  610 . The initial reference value to be stored may correspond to an initial estimation of the reference value that matches the current operating environment. For example, momentarily to  FIGS. 3 and 6 , if the processor  516  determines that the phone is in the purse  305 , then the processor  516  may consult a lookup table to determine a predetermined reference value to be stored in the storage unit  605  such that the initial target frequency achieved by the control system  600  generally corresponds to the phone being located in the purse  305 . This initial target frequency stored in the storage unit  605  may be optimized by subsequent operations. 
     Referring back to  FIG. 8 , block  820  includes a decision block to determine whether the initial reference value is to be optimized. In the event that no optimization is desired, such as when the control system  600  determines that the initial reference value achieves a target frequency that is within a threshold of a predetermined maximum target frequency, then control may flow to block  825 , where the motor  520  may be actuated corresponding to the initial reference value. 
     On the other hand, in the event that the block  820  determines that optimization is desired, then a dithering process may be utilized to determine the target frequency of the electronic device  500 . This dithering process may begin in block  830  where the control signal provided to the motor  520  may be increased, for example, by increasing the frequency as illustrated in the section  705  of  FIG. 7 . In block  835 , each time the control signal is increased by the controller  615 , this value may be stored for determination of the target frequency of the electronic device  500 . Next, in block  840  the control signal provided to the motor  520  may be decreased, for example, by decreasing the frequency with the controller  615  as illustrated in the section  710  of  FIG. 7 . In block  845 , each time the control signal is decreased, this value may be stored for determination of the target frequency of the electronic device  500 . 
     Next, in block  850 , the microprocessor  516  may compare the values stored in blocks  835  and  845  and adjust the reference value in the storage unit  605  accordingly. For example, if the value stored during block  835  is greater than the value stored during block  845 , then increasing the control signal per block  830  may result in the electronic device  500  getting closer to its target frequency than decreasing the control signal per block  840 . Thus, the controller  615  may increase the frequency of the control signal to the motor  520  by increasing the reference value stored in the storage unit  605  per block  855  and then control may flow back to block  830  where the dithering process begins again. 
     Likewise, if the value stored during block  845  is greater than the value stored during block  835 , then decreasing the control signal per block  840  may result in the electronic device  500  getting closer to its target frequency than increasing the control signal per block  830 . Thus, the controller  615  may decrease the frequency of the control signal to the motor  520  by increasing the reference value stored in the storage unit  605  per block  860  and then control may flow back to block  830  where the dithering process begins again. 
     The dithering operations shown in blocks  830 - 845  are merely illustrative of the operations that may be implemented in determining the maximum target frequency of the electronic device  500  in its current operating environment and the operations  800  shown in  FIG. 8  may vary in other embodiments. For example, in some embodiments, there may be a disproportionate number of increases (block  830 ) in the control signal compared to decreases (block  840 ) in the control signal or vice versa. Also, in some embodiments, instead of modifying the frequency of the control signal, other portions of the control signal, such as the duty cycle or amplitude of the voltage, may be modified during the dithering process. 
     In still other embodiments, the maximum target frequency may be determined by stepping through reference values incrementally. For example, the reference value stored in the storage unit  605  may be substantially zero (e.g., on the order of several hertz) and this reference value may be stepped up from this initial value to a maximum reference value. As this reference value is stepped and the control system  600  reacts to this changing reference value, the measurement of the accelerometer  510  may be stored by the processor  516  in order to find a maximum target frequency of the electronic device  500 . By stepping through a range of reference values in this manner, the processor  516  may determine if there are multiple harmonic target frequencies in the target frequency spectrum of the electronic device  500  and determine which of these harmonics produces the largest target frequency of the electronic device  500 . 
     Because one or more characteristics of the motor  520  may vary as a function of temperature (e.g., the electrical resistance of windings in the motor may increase with temperature), wear (e.g., the brushes that commutate the windings in the motor  520  may have an increasing the electrical resistance over time), and/or friction (e.g., the internal bearing structures of the motor  520  may have an increase in the amount of friction over time, causing the motor to spin more slowly in response to applied voltage). These characteristics may include macro scale changes due to aging and wear and/or micro scale changes due to temporary heating in a hot car or due to the generation of heat in the motor windings during operation. Using one or more of the above identified methods, the motor  520  may be operated in such a manner so as to counteract one or more of these effects. For example, using a PWM control signal, in conjunction with measurements from the one or more sensors, changes in performance of the motor  520  as a function of time may be compensated for. Such measurements could be inferred indirectly from measurements of the armature resistance of the motor  520  (e.g., to compensate for temperature/brush wear) or directly from measurements of motor speed at a known duty cycle (e.g., using the accelerometer  510 ). In addition, while these degradations in performance may be compensated for, they may also be used to trigger a repair or diagnostic history to be communicated to the user, or to the manufacturer or seller of the device.

Metadata:
Filing Date: 20090930
Publication Date: 20131008
Grant Date: 20131008
Priority Date: 20090930
Inventors: PAKULA DAVE
HILL MATTHEW
HUWE ETHAN LARRY
ROTHKOPF FLETCHER
DINH RICHARD HUNG MINH
Assignee: APPLE INC
CPC Classifications: [{"code": "H04M2250/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M19/047", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M2250/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "G08B23/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G08B23/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M19/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G08B25/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M19/047", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M19/04", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 43780965