COUPLING ESTIMATION IN WIRELESS CHARGING SYSTEMS

Abstract

Handling k-estimation errors in a wireless power transmission system can involve performing a k-estimation during a digital ping phase of a wireless power transmission negotiation; determining that an error occurred during the k-estimation; determining whether the wireless power receiver is available to assist in correcting the error; and, in response to determining that an error occurred during the k-estimation and that the wireless power receiver is available to assist in correcting the error, performing a full-mode error correction procedure in which the wireless power transmitter works with the wireless power receiver to correct the error that occurred during the k-estimation.and, in response to determining that an error occurred during the k-estimation and the wireless energy receiver is not available to assist in correcting the error, include performing a restricted-mode error correction procedure in which the wireless energy transmitter attempts to correct the error that occurred during the k-estimation without assistance from the wireless energy receiver.

Description

STATE OF THE ART

[0001] Wireless power transfer is used in various electronic devices. For example, smartphones, tablet computers, smartwatches, wireless headphones, styluses, etc., can use wireless power transfer to facilitate charging of batteries within the devices and / or to power the devices during operation. SUMMARY

[0002] A method for handling k-estimation errors in a wireless power transmission system, which includes a wireless power transmitter and a wireless power receiver, can be performed by the wireless power transmitter and can include performing a k-estimation during a phase of a digital ping of a wireless power transmission negotiation; determining that an error occurred during the performance of the k-estimation; and determining whether the wireless power receiver is available to assist in correcting the error.In response to the determination that an error occurred during the k-estimation process and the wireless energy receiver is available to assist in correcting the error, the procedure may include performing a full-mode error correction procedure in which the wireless energy transmitter works in conjunction with the wireless energy receiver to correct the error that occurred during the k-estimation process; and in response to the determination that an error occurred during the k-estimation process and the wireless energy receiver is not available to assist in correcting the error, the procedure may include performing a restricted-mode error correction procedure in which the wireless energy transmitter attempts to correct the error that occurred during the k-estimation process without the assistance of the wireless energy receiver.

[0003] Determining that an error occurred during the k-estimation process can be based on the wireless energy receiver sending an extended identification packet containing a restricted field set to 1 for restricted mode.

[0004] Performing an error correction procedure in restricted mode may further include removing the power signal and resetting the wireless power link; performing one or more corrective actions; and initiating another phase of a digital ping. The one or more corrective actions may include initiating another digital ping at a second voltage level different from the first voltage level of the digital ping. Performing an error correction procedure in full mode may further include entering an error negotiation phase and transmitting the error to the wireless power receiver.Transmitting the error to the wireless power receiver can include sending a not acknowledged packet (NAK packet, NAK = not acknowledged) in response to a configuration packet (CFG packet) from the PRx; sending an error packet (ERR packet) in response to a GET packet from the wireless power receiver.

[0005] Performing a full-mode error correction procedure can further include, in response to receiving information from the wireless power receiver that allows the error to be resolved, completing the wireless power transfer negotiation phase, and in response to not receiving information from the wireless power receiver that allows the error to be resolved: receiving a request from the wireless power receiver to exit the negotiation phase; removing the power signal, resetting the wireless power link; performing one or more corrective actions; and initiating another phase of a digital ping. Additional information received from the wireless power receiver may include ecosystem scaling coefficients. The ecosystem scaling coefficients may be received in an ecosystem scaling coefficient packet.The information that allows the error to be corrected may be included in an EPT / rst packet from the wireless power receiver.

[0006] A wireless power transmitter can include control and communication switching logic that, during a digital ping phase of a wireless power transmission negotiation, performs a k-estimation; determines that an error occurred during the k-estimation; determines whether the wireless power receiver is available to assist in correcting the error; and, in response to determining that an error occurred during the k-estimation and that the wireless power receiver is available to assist in correcting the error, performs a full-mode error correction procedure in which the wireless power transmitter works with the wireless power receiver to correct the error that occurred during the k-estimation.The full-mode error correction procedure may include entering an error negotiation phase and transmitting the error to the wireless power receiver. Alternatively, in response to determining that an error occurred during the k-estimation and that the wireless power receiver is unavailable to assist in correcting the error, the transmitter control logic may perform a restricted-mode error correction procedure. In this procedure, the wireless power transmitter attempts to correct the error that occurred during the k-estimation without assistance from the wireless power receiver. The restricted-mode error correction procedure may include removing the power signal and resetting the wireless power link; performing one or more corrective actions; and initiating another phase of a digital ping.

[0007] Determining that an error occurred during k-estimation can be based on receiving an extended identification packet from a wireless power receiver in which a restricted mode field is set to 1. One or more corrective actions may include the control and communication switching logic initiating another digital ping at a second voltage level different from the first voltage level of the digital ping. Transmitting the error to the wireless power receiver may involve the control and communication switching logic sending an unacknowledged packet (NAK packet) in response to a configuration packet (CFG packet) from the PRx and sending an error packet (ERR packet) in response to a GET packet from the wireless power receiver.Performing a full-mode error correction procedure may further include, in response to receiving information from the wireless power receiver that allows the error to be corrected: completing the wireless power transfer negotiation phase, the information allowing the error to be corrected being included in an EPT / rst packet from the wireless power receiver received by the control and communication switching logic; and in response to not receiving information from the wireless power receiver that allows the error to be corrected: receiving a request from the wireless power receiver to exit the negotiation phase; removing the power signal, resetting the wireless power link; performing one or more corrective actions; and initiating another phase of a digital ping.Additional information received by the wireless energy receiver may include scaling coefficients received in an ecosystem scaling coefficient package.

[0008] A method for handling k-estimation errors in a wireless power transmission system, which includes a wireless power transmitter and a wireless power receiver, can be performed by the wireless power receiver and can include receiving a notification from the wireless power transmitter that an error occurred during a phase of a digital ping; receiving a specified cause of the error in the phase of a digital ping from the wireless power transmitter; in response to the fact that the specified cause is a k-estimation error and is correctable by the wireless power receiver, transmitting additional information to the wireless power transmitter, thereby cooperating with the wireless power transmitter to eliminate the error;and, in response to the fact that the indicated cause cannot be corrected by the wireless power receiver, include transmitting a reset message to the wireless power transmitter, causing the wireless power transmitter to attempt to correct the fault itself.

[0009] The additional information can include an extended identification packet containing a restricted field set to 1 for restricted mode. Transmitting additional information to the wireless power transmitter, which interacts with the wireless power transmitter to resolve the error, can include transmitting ecosystem scaling coefficients in an ecosystem scaling coefficient packet. The reset message can include an EPT / rst packet.

[0010] A wireless power receiver can include control and communication switching logic that receives a notification from the wireless power transmitter that an error occurred during a phase of a digital ping; receives a specified cause of the error in the digital ping phase from the wireless power transmitter; in response to the fact that the specified cause is a k-estimation error and is correctable by the wireless power receiver, transmits additional information to the wireless power transmitter, thereby cooperating with the wireless power transmitter to correct the error; and in response to the fact that the specified cause is not correctable by the wireless power receiver, transmits a reset message to the wireless power transmitter, causing the wireless power transmitter to attempt to correct the error itself.

[0011] The additional information can include an extended identification package containing a Restricted field set to 1 for restricted mode. The additional information can also include the transmission of ecosystem scaling coefficients in an ecosystem scaling coefficient package. The reset message can include an EPT / rst package. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 illustrates a simplified block diagram of a wireless power transmission system. Fig. Figure 2 illustrates a flowchart of a technique for handling errors in a k-estimation process of a wireless power transmission system. Fig. Figure 3 illustrates a table with potential sources and solutions for k-estimation errors. Fig. Figure 4 illustrates an exemplary communication flow between a PTx and a PRx using a k-estimation error handling process in a restricted mode. Fig. Figure 5 illustrates an exemplary communication flow between a PTx and a PRx using a k-estimation error handling process in a first full-mode scenario. Fig. Figure 6 illustrates an exemplary communication flow between a PTx and a PRx using a k-estimation error handling process in a second full-mode scenario. Fig. Figure 7 illustrates an example data package structure for exchanging ecosystem scaling coefficients between a PTx and a PRx. Fig. Figure 8 illustrates an example data packet structure for exchanging error information between a PTx and a PRx. DETAILED DESCRIPTION

[0012] The following description presents numerous specific details for explanatory purposes, in order to provide a comprehensive understanding of the disclosed concepts. For the sake of simplicity, some drawings in this disclosure depict structures and devices in block diagram form. For clarity, this disclosure does not describe all features of an actual implementation. Furthermore, the language used in this disclosure has been chosen for readability and instructional purposes, and not to delimit or restrict the subject matter disclosed. Rather, the accompanying claims are provided for that purpose. All trademarks mentioned herein are used solely for the purpose of identifying examples and are the property of their respective owners.

[0013] Various embodiments of the disclosed concepts are illustrated in the accompanying drawings, where identical references denote identical elements, in an exemplary and non-limiting manner. For clarity and comprehensibility, reference numerals have been repeated in the various figures where appropriate to indicate corresponding or analogous elements. Furthermore, numerous specific details are set forth to provide a comprehensive understanding of the implementations described herein. In other cases, methods, procedures, and components have not been described in detail so as not to obscure the relevant function being described. References to "a," "a particular," or "another" embodiment in this disclosure do not necessarily refer to the same or a different embodiment, and they mean at least one.A given figure may be used to illustrate the features of more than one embodiment or more than one kind of the disclosure, and not all elements in the figure may be necessary for a given embodiment or kind. A reference numeral, when provided in a given drawing, refers to the same element in all the different drawings, although it may not be repeated in every drawing. Unless otherwise indicated, the drawings are not to scale, and the proportions of certain parts may be exaggerated for better illustration of details and features of the present disclosure.

[0014] Fig. Figure 1 illustrates a simplified block diagram of the energy transmission system 100. The energy transmission system includes an energy transmitter (PTx) 110, which wirelessly transmits energy to an energy receiver (PRx) 120 via inductive coupling 130. The energy transmitter 110 can receive input energy, which is converted by an inverter 114 into an alternating voltage with specific voltage and frequency characteristics. The inverter 114 can be controlled by a control unit / communication module 116, which operates as described below. In various embodiments, the inverter control unit and the communication module can be implemented in a common system, such as a microprocessor-based system, a microcontroller, or the like.In other embodiments, the inverter control unit can be implemented by a separate control unit module and communication module, which provide communication between them. The inverter 114 can be constructed using any suitable circuit topology (e.g., full bridge, half bridge, etc.) and implemented using any suitable semiconductor switching device technology (e.g., MOSFETs, iGBTs, etc.) fabricated using silicon, silicon carbide, or gallium nitride devices.

[0015] The inverter 114 can supply the generated alternating voltage to a transmitter coil 112. In addition to a wireless coil, which enables magnetic coupling with the receiver, the inverter can also be used in the following configuration: Fig. Figure 1 illustrates transmitter coil block 112, which includes tuning logic, such as additional inductors and capacitors, to facilitate transmitter operation under varying conditions, such as different degrees of magnetic coupling with the receiver, different operating frequencies, etc. The wireless coil itself can be constructed in a variety of different ways. In some embodiments, the wireless coil can be formed as a winding of wire around a suitable coil. In other embodiments, the wireless coil can be formed as conductive traces on a printed circuit board. Other arrangements are also possible and can be used in conjunction with the various embodiments described herein. The wireless transmitter coil can also have a core made of magnetically permeable material (e.g.,Include a ferrite core configured to influence the coil's flux pattern in a manner suitable for the specific application. The teachings contained herein may be applied in connection with any of a wide variety of transmitter coil arrangements suitable for a given application.

[0016] The PTx control / communication module 116 can monitor the transmitting coil and use the derived information to control the inverter 114 according to a given situation. For example, the control / communication module can be configured to operate the inverter 114 at a given frequency or output voltage, depending on the specific application. In some embodiments, the control / communication module can be configured to receive information from the PRx device and control the inverter 114 accordingly. This information can be received via the power transmission coils (i.e., in-band communication) or via a separate communication channel (not shown, i.e., out-of-band communication).For in-band communication, the control / communication module 116 can capture and decode signals (such as voltage, frequency, or load fluctuations) imposed on the magnetic link by the PRx to receive information and can instruct the inverter to modulate the supplied power by manipulating various parameters of the generated voltage (such as voltage, frequency, phase, etc.) to send information to the PRx. In some embodiments, the control / communication module can be configured to use frequency-shift keying (FSK) communication, where the frequency of the inverter signal is modulated to transmit data to the PRx. The control / communication module 116 can also be configured to capture amplitude-shift keying (ASK) or load-modulation-based communication from the PRx.In both cases, the control / communication module 126 can be configured to vary the current drawn at the receiver side to manipulate the waveform seen on the Tx coil, thus transmitting information from the PRx to the PTx. For out-of-band communication, additional modules can be provided to enable communication between the PTx and PRx, such as WiFi, Bluetooth, other radio links, or another suitable communication channel.

[0017] As mentioned above, the control / communication module 116 can be a single module, for example, implemented on a single integrated circuit, or it can be composed of multiple modules / devices implemented on different integrated circuits or a combination of integrated and discrete circuits, incorporating both analog and digital components. The teachings herein are not limited to any particular arrangement of control / communication switching logic.

[0018] The PTx device 110 can optionally include other systems and components, such as a separate communication module 118. In some embodiments, the communication module 118 can communicate with a corresponding module tag in the PRx via the energy transfer coils. In other embodiments, the communication module 118 can communicate with a corresponding module using a separate physical channel 138.

[0019] As mentioned above, the energy transmission system also includes a wireless energy receiver (PRx) 120. The wireless energy receiver can include a receiver coil 122, which can be magnetically coupled 130 to the transmitter coil 112. As with the transmitter coil 112 discussed above, the Fig. Figure 1 illustrates the receiver coil block 122, which may include a tuning logic such as additional inductors and capacitors to facilitate transmitter operation under varying conditions, such as different degrees of magnetic coupling with the receiver, different operating frequencies, etc. The wireless coil itself can be constructed in a variety of different ways. In some embodiments, the wireless coil may be formed as a winding of wire around a suitable coil. In other embodiments, the wireless coil may be formed as conductive traces on a printed circuit board. Other arrangements are also possible and may be used in conjunction with the various embodiments described herein. The wireless receiver coil may also have a core of magnetically permeable material (e.g.,Include a ferrite core configured to influence the coil's flux pattern in a manner suitable for the specific application. The teachings contained herein may be applied in connection with any of a wide variety of receiver coil arrangements suitable for a given application.

[0020] The receiver coil 122 outputs an induced alternating voltage via magnetic induction through the transmitter coil 112. This output alternating voltage can be supplied to a rectifier 124, which provides a direct current output power for one or more loads associated with the PRx device. The rectifier 124 can be controlled by a control unit / communication module 126, which operates as further described below. In various embodiments, the rectifier control unit module and the communication module can be implemented in a common system, such as a system based on a microprocessor, a microcontroller, or the like. In other embodiments, the rectifier control unit can be implemented by separate control unit modules and communication modules, which provide communication between them.The rectifier 124 can be constructed using any suitable circuit topology (e.g. full bridge, half bridge, etc.) and implemented using any suitable semiconductor switching device technology (e.g. MOSFETs, iGBTs, etc.) manufactured using silicon, silicon carbide, or gallium nitride devices.

[0021] The PRx control / communication module 126 can monitor the receiver coil and use the information derived from this monitoring to control the rectifier 124 according to a given situation. For example, the control / communication module can be configured to cause the rectifier 124 to provide a given output voltage depending on the specific application. In some embodiments, the control / communication module can be configured to send information to the PTx device to effectively control the power supplied to the receiver. This information can be received by being transmitted over the power transfer coils (i.e., in-band communication) or can be sent over a separate communication channel (not shown, i.e., out-of-band communication).For in-band communication, the control / communication module 126 can, for example, modulate load current or other electrical parameters of the received energy to send information to the PTx. In some embodiments, the control / communication module 126 can be configured to capture and decode signals imposed on the magnetic link (such as voltage, frequency, or load fluctuations) by the PTx in order to receive information from the PTx. In some embodiments, the control / communication module 126 can be configured to receive frequency-shift keying (FSK) communication, in which the frequency of the inverter signal has been modulated to transmit data to the PRx. The control / communication module 126 can be configured to generate amplitude-shift keying (ASK) or load-modulation-based communication from the PRx.In both cases, the control / communication module 126 can be configured to vary the current drawn at the receiver side to manipulate the waveform seen on the Tx coil, thus transmitting information from the PRx to the PTx. For out-of-band communication, additional modules can be provided to enable communication between the PTx and PRx, such as WiFi, Bluetooth, other radio links, or another suitable communication channel.

[0022] As mentioned above, the control / communication module 126 can be a single module, for example, provided on a single integrated circuit, or it can be composed of several modules / devices provided on different integrated circuits or a combination of integrated and discrete circuits, incorporating both analog and digital components. The teachings herein are not limited to a specific arrangement of the control / communication switching logic. The PRx device 120 can optionally include other systems and components, such as a communication module (comm. module) 128. In some embodiments, the communication module 128 can communicate with a corresponding module in the PTx via the power transfer coils.In other embodiments, the communication module 128 can communicate with a corresponding module or tag using a separate physical channel 138.

[0023] Numerous variations and improvements to the wireless power transmission system 100 described above are possible, and the following teachings are applicable to any of these variations and improvements.

[0024] In wireless power transfer applications, a PTx can estimate or calculate a coupling coefficient (denoted "k") between the PTx and a PRx. The coupling coefficient k is a property of a magnetic circuit that depends at least partially on the relative positions / orientation between the PTx and PRx coils and can be used to estimate or calculate the maximum amount of energy the PTx can deliver to the PRx. The k estimation can be performed by the PTx, for example, through its control unit and communication switching logic, as described above, as part of a "digital ping" that occurs at the beginning of the power transfer process. In some cases, examples of which are discussed in more detail below, the k estimation procedure may be subject to errors.It may be desirable for the PTx and / or the PRx to correct the cause of such errors in order to enable a more accurate k-estimation, which can lead to better wireless power transmission.

[0025] Fig. Figure 2 illustrates a flowchart 200 of a technique for handling errors in a k-estimation process of a wireless power transmission system, which includes a PTx and a PRx, as described above with reference to Fig. 1. The process can be used as part of setting up a wireless power transfer according to a standard protocol, such as the Qi wireless power transfer standard published by the Wireless Power Consortium, or according to a proprietary wireless power transfer protocol. The techniques described herein are described with reference to Qi wireless power transfer standards; however, in certain applications, equivalent or corresponding features of a proprietary protocol may be used. An error may occur as part of the estimation of k by the PTx, for example, during the “digital ping” phase of initiating the wireless power transfer. Examples of such errors are described below with reference to Fig. 3 is discussed in more detail. In any case, the PTx in Block 201 can determine the “mode” for the k-estimation error handling process. A first mode, described herein as the “restricted” mode, can be used in cases where the PRx is unable to assist in clearing an error condition. This might be, for example, if the PRx device's battery is completely depleted and it is therefore not fully functional at the time wireless power transfer is initiated. Other causes for such a condition are also possible. In any case, in restricted mode, the PTx attempts to clear the error condition itself, as described in more detail below and illustrated on the right side of Flowchart 200.A second mode, described herein as the "Full" mode, can be used in cases where the PRx is potentially able to assist in clearing a fault condition. In any case, in Full mode, the PTx communicates with the PRx, as described in more detail below, to attempt to clear the fault condition. In some cases, this interaction can clear the fault condition, which is shown on the left side of flowchart 200. Otherwise, in some cases, the interaction between the PTx and PRx may fail to clear the fault condition, in which case the PTx may proceed to operations similar to the restricted mode, as discussed in more detail below.

[0026] If, referring again to block 201 of flowchart 200, the PTx determines that the PRx is unable to assist in eliminating the fault condition that is causing the k-estimation error, the PTx can remove the power signal (block 202), effectively resetting the wireless power link. Subsequently, in block 203, the PTx can perform one or more corrective actions to attempt to rectify the fault condition. Examples of these activities (labeled "B") are shown in Fig. 2 and Fig. 3 are discussed in more detail below. After attempting to correct the error condition, the PTx can retry the digital ping (block 204), making another k-estimation attempt. If the subsequent k-estimation is successful, wireless power transfer can proceed normally according to the standard or proprietary protocol. Otherwise, if an error condition persists, the process of Fig. 2. Repeated to attempt to eliminate the new or persistent error condition. As described in block 204 of Fig. Figure 2 shows that the digital ping occurs at a frequency of 128 kHz, which corresponds to at least some versions of the Qi standards for wireless power transfer. However, the digital ping could also occur at any other suitable frequency according to a corresponding standard or proprietary protocol, and therefore the techniques described herein should not be understood as being limited to a specific operating frequency.

[0027] If, referring again to block 201 of flowchart 200, the PTx determines that the PRx may be able to assist in removing the fault condition that leads to the k-estimation error, the PTx can proceed to a "Negotiation with Fault" phase in block 205. This determination might be based, for example, on the PRx transmitting its XID (Extended Identification) packet and setting the Restricted field in the Restricted Mode XID packet to 1. As described in block 205 of Fig. As shown in Figure 2, the negotiation phase with fault is described as occurring at a frequency of 128 kHz, which corresponds to at least some versions of the Qi standards for wireless power transfer. However, the negotiation phase with fault could also occur at any other suitable frequency according to an appropriate standard or proprietary protocol, and therefore the techniques described herein should not be understood as being limited to a particular operating frequency. In any case, the PTx can then communicate with the PRx to negotiate a wireless power transfer link, which may include communications to request that the PRx assist in resolving the fault (Block 206). Examples of these activities (labeled "A") are shown in Figure 2. Fig. 2 and Fig. 3 are discussed in more detail below. These and other activities described herein as being performed by the PRx can be carried out by the PRx's control and communication switching logic, as described above with reference to Fig. 1 described. Subsequently, the PTx and / or the PRx can determine in block 207 whether the fault condition has been resolved. If so, the power transfer negotiation and wireless power transfer can continue normally. Otherwise, if the cooperation between the PTx and PRx in resolving the fault condition was unsuccessful, the PRx can request an exit from the negotiation phase (block 208), and the PTx can proceed as described above regarding restricted mode, beginning with the PTx removing the power signal (block 202), resetting the wireless power transfer link, and otherwise proceeding as described above in restricted mode.

[0028] Fig. Figure 3 illustrates Table 300 with potential sources and solutions for k-estimation errors. The first column, 331, of Table 300 lists exemplary reasons for a k-estimation error. This list is not exhaustive, and other reasons may exist. The second column, 332, of Table 300 lists possible actions that the PRx can take to assist in eliminating the error condition (marked with an 'A' corresponding to Block 206 of Fig. 2 (labeled as discussed above). In some fault conditions, the PRx may not be able to take any action to correct the fault. The third column, 333, of Table 300 lists possible actions that the PTx can take to correct the fault condition, either in conjunction with the PRx or on its own.

[0029] As illustrated in the first row of Table 300, a k-estimation error can be caused by a measurement error. This could be a timing error or an unexpected out-of-range value measured by the PTx during the k-estimation phase of a digital ping or any other k-estimation phase. In this case, the PTx cannot take action to rectify the condition, and the PTx's action is to retry the digital ping, which would result in a transition over block 208, as described above with reference to Fig. 2 described.

[0030] As illustrated in the second row of Table 300, a k-estimation error can be caused by using a digital ping level that does not permit k-estimation. That is, different wireless power transfer embodiments may use different voltage levels for a digital ping. As an example, a half-bridge low voltage (denoted HB_L in the figures of this application) of about 11.5 V can be used, corresponding to the inverter voltage applied by the PTx to the wireless power transfer coil, and the PTx may be configured to use this voltage with a k-estimation technique.Alternatively, a half-bridge high voltage (denoted HB_H in the figures of this application) of approximately 13 V can be used, corresponding to the inverter voltage applied by the PTx to the coil for wireless power transmission, and the PTx may not be configured to use this voltage with a k-estimation technique. In this case, the PTx can do nothing to eliminate the fault condition, and the action of the PTx is to switch to a different level of a digital ping (e.g., HB_L) that allows k-estimation and to repeat the digital ping, which would result in a transition via block 208, as described above with reference to [reference to figure]. Fig. 2 described.

[0031] As illustrated in the third row of Table 300, a k-estimation error can be caused by a digital ping level that requires the PRx to provide ecosystem scaling coefficients to the PTx. For example, the PTx may have the necessary information, such as scaling coefficients, about a PRx to perform a successful k-estimation at one digital ping voltage, e.g., HB_L, but not the necessary information about the PRx to perform a successful k-estimation at another digital ping voltage, e.g., HB_H. The same situation could apply to digital pings performed at different frequencies, and so on. If the PRx device is able to provide the PTx with the scaling coefficients, the PRx can certainly help correct the k-estimation error by providing such coefficients to the PTx.The PTx can then repeat the digital ping with the newly received ecosystem scaling coefficients and / or with a different voltage (or frequency, etc.) of a digital ping, which may include a change in power mode.

[0032] Ecosystem scaling enables a PTx and a PRx to determine various electrical and magnetic parameters of the wireless power transmission link by exchanging coefficients that allow for the conversion of measured properties between the two specific devices to fit a model determined with respect to a corresponding reference device. Details of ecosystem scaling systems and parameters are outside the scope of protection of the present disclosure; however, examples can be found in the applicant's concurrently pending US patent application 17 / 681,363 entitled "Wireless Power Systems with Shared Inductive-Loss Scaling Factors," filed on February 25, 2022.

[0033] Fig. Figure 4 illustrates an exemplary communication flow 400 between a PTx and a PRx using a k-estimation error handling process in a restricted mode, as described above with reference to Fig. 2 described. As noted above, restricted mode can be used when the PRx is unable to assist in eliminating a k-estimation error condition. In Fig. 4 (and the following Fig. 5 and Fig. 6) Messages or packets sent from the PRx to the PTx are labeled white, and messages or packets sent from the PTx to the PRx are labeled black. At 1, the PTx may initiate a digital ping process, which may cause the PRx to provide one or more initial message(s) 440, 441. According to at least some versions of the Qi standard, this may include a signal strength packet (SIG packet) and an identification packet (ID packet). This may also include a measurement of VGleichr. (the output voltage of the PRx, as described above with reference to) Fig. The PRx triggers a measurement of the rectifier (the inverter voltage applied by the PTx to the coil of the wireless power transmitter) by the PRx. The PRx can then send an Extended Identification (XID) packet 442 to the PTx, which may contain the measured rectifier voltage value. The PTx can then use this rectifier voltage value received from the PRx, along with the rectifier voltage value measured by the PTx, to calculate a voltage conversion gain and a corresponding estimate of the coupling factor k.

[0034] If the PTx determines that it is unable to estimate k, which is one of the above with reference to Fig. If there are three reasons discussed, or other reasons, he can remove the energy signal at point 2 (see also block 202 of Fig. 2) and in case 3, implement one or more corrective actions (see also block 203 of Fig. 2) This may include selecting a different level of a digital ping, changing the power mode, etc. Then, at 4, the PTx may initiate the digital ping again, which may result in continued operation in restricted mode or a transition to full mode, as described in more detail below.

[0035] Fig. Figure 5 illustrates an exemplary communication flow 500 between a PTx and a PRx using a k-estimation error handling process in a first full-mode scenario where the PRx is able to assist in clearing the error state, as described above with reference to Fig. 2 was described. Fig. 5 (and the following Fig. 6) Messages or packets sent from the PRx to the PTx are labeled white, and messages or packets sent from the PTx to the PRx are labeled black. At 1, the PTx may initiate a digital ping process, which may cause the PRx to provide one or more initial message(s) 540, 541. According to at least some versions of the Qi standard, this may include a signal strength packet (SIG packet) and an identification packet (ID packet). This may also include a measurement of VGleichr. (the output voltage of the PRx, as described above with reference to) Fig. The PRx triggers a measurement of the rectifier (the inverter voltage applied by the PTx to the coil of the wireless power transmitter) by the PRx. The PRx can then send an Extended Identification (XID) packet 542 to the PTx, which may contain the measured rectifier voltage value. The PTx can then use this rectifier voltage value received from the PRx, along with the rectifier voltage value measured by the PTx, to calculate a voltage conversion gain and a corresponding estimate of the coupling factor k.

[0036] If the PTx determines that it is unable to estimate k, which is one of the above with reference to Fig. For reasons discussed in point 3, or for other reasons, it may respond to a subsequent configuration packet (CFG packet) 543 from the PRx with an unacknowledged packet (NAK packet) 544, thereby triggering a "negotiation with failure" phase, as described above with reference to block 205 of Fig. 2 described. Subsequently, at point 3, the PRx can send a GET packet 545 requesting the error code from the PTx, which the PTx can provide in an ERR packet 546, an example of which is described below. For instance, the ERR packet 546 might indicate that the k-estimation error was due to missing ecosystem scaling coefficients. Then, at point 4, the PRx can send a KEST COEFF packet 547 to the PTx, which might represent the PRx's contribution to resolving the error condition. The PTx can then send an ACK packet 548 indicating receipt of the coefficients or otherwise acknowledging the PRx's contribution to resolving the error condition.

[0037] The PRx can then send another GET packet (549) at address 5, requesting any further error codes. The PTx can then send a response ERR packet (550), indicating either any additional or further error states or indicating that no error states exist. If no additional or further error states exist, the PRx can send a frequency selection packet (551) at address 6, initiating a transition to operation at a different frequency, such as 360 kHz. This can be acknowledged by the PTx sending an ACK packet (552). The PRx can then send a Negotiation Complete packet (SRQ / en packet) 553, which can also be acknowledged by the PTx (554), with the PRx then sending an EPT Re-Ping packet (EPT / rep) 555, followed by an optional transition to the new operating frequency.This frequency transition is optional and / or can be performed according to some versions of a standard or proprietary protocol. In other embodiments or applications, operation can continue at the original frequency, which may or may not be 128 kHz. In such cases, the PRx and PTx can complete the negotiation process for wireless power transmission operation with all desired parameters for frequency, voltage, energy level, etc., by other means.

[0038] Fig. Figure 6 illustrates an exemplary communication flow between a PTx and a PRx using a k-estimation error handling process in a second full-mode scenario where the PRx is unable to assist in clearing the error state, as described above with reference to Fig. 2 was described. Fig. 6. Messages or packets sent from the PRx to the PTx are labeled white, and messages or packets sent from the PTx to the PRx are labeled black. At 1, the PTx may initiate a digital ping process, which may cause the PRx to provide one or more initial message(s) 640, 641. According to at least some versions of the Qi standard, this may include a signal strength packet (SIG packet) and an identification packet (ID packet). This may also include a measurement of VGleichr. (the output voltage of the PRx, as described above with reference to...) Fig. The PRx triggers a measurement of the rectifier (the inverter voltage applied by the PTx to the coil of the wireless power transmitter) by the PRx. The PRx can then send an Extended Identification (XID) packet 642 to the PTx, which may contain the measured rectifier voltage value. The PTx can then use this rectifier voltage value received from the PRx, along with the rectifier voltage value measured by the PTx, to calculate a voltage conversion gain and a corresponding estimate of the coupling factor k.

[0039] If the PTx determines that it is unable to estimate k, which is one of the above with reference to Fig. For reasons discussed in point 3, or for other reasons, it may respond to a subsequent configuration packet (CFG packet) 643 from the PRx with an unacknowledged packet (NAK packet) 644, thereby triggering a "negotiation with failure" phase, as described above with reference to block 205 of Fig. 2 described. Subsequently, at 3, the PRx can send a GET packet 645 requesting the error code from the PTx, which the PTx can provide in an ERR packet 646, an example of which is described below. As an example, the ERR packet 646 might indicate that the k-estimation error was due to the level of a digital ping. Upon receiving this ERR packet, the PRx may determine that it is unable to assist in correcting this error, and thus, at 4, the PRx can send an EPT / rst packet 647 to the PTx, which can cause the PRx to exit the negotiation phase and further enable the PTx to attempt to correct the k-estimation error itself, as described above. This can then be done at 5 by another digital ping technique, resulting in a retry of the k-estimation, and so on.

[0040] The PRx can then send another GET packet (549) at address 5, requesting any further error codes. The PTx can then send a response ERR packet (550), indicating either any additional or further error states and potentially providing information that allows the error to be resolved, or indicating that no error states exist. If no additional or further error states exist, the PRx can send a frequency selection packet (551) at address 6, initiating a transition to operation at a different frequency, such as 360 kHz. This can be acknowledged by the PTx sending an ACK packet (552). The PRx can then send a negotiation-completed packet (SQQ / en packet) 553, which can also be acknowledged by the PTx (554), with the PRx then sending an EPT-re-ping packet (EPT / rep) 555, followed by an optional transition to the new operating frequency.This frequency transition is optional and / or can be performed according to some versions of a standard or proprietary protocol. In other embodiments or applications, operation can continue at the original frequency, which may or may not be 128 kHz. In such cases, the PRx and PTx can complete the negotiation process for wireless power transmission operation with all desired parameters for frequency, voltage, energy level, etc., by other means.

[0041] Fig. Figure 7 illustrates an exemplary data packet structure 700 for exchanging ecosystem scaling coefficients between a PTx and a PRx. The data packet structure can be used in the context of a version of the Qi standard or in the context of a proprietary wireless power transfer protocol. In one embodiment, the packet 761 can include five bytes (B0 to B4), each comprising eight bits (b0 to b7). One or more bits (e.g., bits b1 to b7 of byte B0) can be reserved for other purposes and / or future use. One bit (e.g., bit b0 of byte B0) can be used as a selector bit. As shown in Table 763, a selector bit value of 0 can be used to indicate that the packet includes k-estimation coefficients for a high-voltage digital ping, and a selector bit value of zero can be a reserved / unallowed value.

[0042] One byte (e.g., byte B1) of packet 761 can be used to provide a first ecosystem scaling parameter (e.g., Alpha0), and another byte (e.g., byte B2) of packet 761 can be used to provide a second ecosystem scaling parameter (e.g., Alpha 1). As listed in Tables 764 and 765, the respective parameter fields of packet 761 can use seven bits to encode the respective parameters, with one bit of each byte reserved as a selector. In other cases, all eight bits could be used to encode the respective parameter. Unused and / or reserved bits of packet 761, such as the reserved bits of byte B0 and the unused bytes B3 and B4, can be set to zero.

[0043] Fig.Figure 8 illustrates an exemplary data packet structure 800 for exchanging error information between a PTx and a PRx. The data packet structure can be used in conjunction with a version of the Qi standard or with a proprietary wireless power transfer protocol. In one embodiment, the packet 866 can include a byte (B0) with eight bits (b0 to b7). Two bits (e.g., bits b0 to b1) can be used to indicate an error. As shown in Table 867, a value of 0 (i.e., binary 00) for the error bits can indicate no error, and a value of 1 (i.e., binary 01) can be used to indicate an error consisting of the inability to perform a k-estimation. Other values ​​(e.g., 2, binary 10, or 3, binary 11) can be reserved. Three bits of byte B0 of packet 866 (e.g., bits b2 to b4) may be reserved, and three bits (e.g., bits b5 to b7) may be used as information bits.As listed in Table 868, an information value of 0 (i.e., binary 000) can be used to indicate that there is no error when the error value is 0, or to indicate an error, that the PTx is unable to successfully perform a k-estimation due to the level of a digital ping when the error value is 1. Similarly, an information value of 1 (i.e., binary 001) in conjunction with an error value of 1 can be used to indicate that the PTx is unable to successfully perform a k-estimation due to missing ecosystem scaling coefficients. An information value of 2 (i.e., binary 010) can be used to indicate that the PTx is unable to successfully perform a k-estimation due to a measurement error. Information values ​​greater than 2 (i.e., binary values ​​011, 100, 101, 110, and 111) may be reserved. Unused and / or reserved bits of packet 866 can be set to zero.

[0044] The foregoing describes various features and embodiments relating to wireless power transfer techniques for addressing errors in a coupling coefficient estimation process performed when initiating wireless power transfer between a PTx and a PRx. Such arrangements can be used in a variety of applications but may be particularly advantageous when used in connection with electronic devices such as mobile phones, tablet computers, laptops, or notebooks, and accessories such as wireless headphones, pens, smartwatches, etc. Although numerous specific features and various embodiments have been described, it is further understood that, unless explicitly stated as mutually exclusive, the various features and embodiments may be combined in different permutations within a given implementation.Therefore, the various embodiments described above are provided for illustrative purposes only and should not be understood as limiting the scope of protection of the disclosure. Various modifications and changes may be made to the principles and embodiments contained herein without deviating from the scope of protection of the disclosure and without deviating from the scope of protection of the claims.

[0045] The foregoing describes exemplary embodiments of wireless power transfer systems capable of transmitting certain information between the PTx and PRx within the system. This disclosure provides that this information transfer enhances the ability of the devices to efficiently provide each other with wireless power signals, thereby facilitating battery charging by sharing the power processing capabilities of the devices. Entities implementing this technology should ensure that, to the extent that sensitive information is used in specific implementations, established data protection policies and / or practices are followed.In particular, such entities are expected to implement and consistently apply data protection practices that are generally recognized as meeting or exceeding industry or governmental requirements for protecting user privacy. Implementers should inform users when identifiable personal information is likely to be transmitted in a wireless power transfer system and allow users to consent to or decline participation. For example, such information may be presented to the user when they place a device on a power transmitter if the power transmitter is configured to request sensitive information from the power receiver. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 17 / 681,363

[0032]

Claims

[1] Method for dealing with K-estimation errors in a wireless power transmission system comprising a wireless power transmitter and a wireless power receiver, wherein the method is performed by the wireless power transmitter and comprising: Performing a K-estimation during a digital ping phase of a wireless power transmission negotiation; Determine that an error occurred during the K-estimation process; Determine if the wireless power receiver is available to help correct the fault; in response to determining that an error occurred during the K-estimation process and that the wireless current receiver is available to assist in correcting the error, perform an error correction procedure in full mode, with the wireless current transmitter working in conjunction with the wireless current receiver to correct the error that occurred during the K-estimation; and In response to the determination that an error occurred during the K-estimation process and the wireless power receiver is unavailable to assist in correcting the error, an error correction procedure is performed in a restricted mode, in which the wireless power transmitter attempts to correct the error that occurred during the K-estimation process without cooperation from the wireless power receiver. [2] Method according to claim 1, wherein the determination that an error has occurred during the execution of the K-estimation is based on the wireless current receiver which sends an extended identification packet containing a restricted field set to 1 for the restricted mode. [3] Method according to claim 1, wherein performing an error correction procedure in the restricted mode further comprises: Removing the power signal, resetting the wireless power connection; Implementing one or more corrective actions; and Initiating another digital ping phase. [4] Method according to claim 3, wherein one or more corrective measures include initiating a further digital ping at a second voltage level that differs from a first voltage level of the digital ping. [5] Method according to claim 1, wherein performing an error correction procedure in full mode further comprises: Entering a negotiation phase with errors; and Communicating the fault to the wireless power receiver. [6] Method according to claim 5, wherein communicating the fault to the wireless current receiver comprises: Sending an unacknowledged (NAK) packet in response to a configuration packet (CFG packet) from the PRx; Sending an error packet (ERR packet) in response to a GET packet from the wireless power receiver. [7] Method according to claim 5, wherein performing an error correction procedure in full mode further comprises: in response to receiving information from the wireless power receiver that allows for the correction of the fault, the negotiation phase of the wireless power transmission is completed; and in response to the fact that no information is being received from the wireless power receiver that would allow the fault to be rectified: Receiving a request from the wireless power receiver to exit the negotiation phase; Removing the power signal, resetting the wireless power connection; Implementing one or more corrective actions; and Initiating another digital ping phase. [8] Method according to claim 7, wherein additional information received by the wireless power receiver includes ecosystem scaling coefficients. [9] Method according to claim 8, wherein the ecosystem scaling coefficients are received in an ecosystem scaling coefficient package. [10] Method according to claim 7, wherein the information enabling the correction of the fault is included in an EPT / rst packet from the wireless power receiver. [11] Wireless power transmitter comprising a control and communication circuit, comprising: performs a K-estimation during a digital ping phase of a wireless power transmission negotiation; determined that an error occurred while performing the K-estimation; determines whether the wireless power receiver is available to help correct the fault; In response to determining that an error occurred during the K-estimation process and that the wireless current receiver is available to assist in correcting the error, the system performs a full-mode error correction procedure in which the wireless current transmitter works in conjunction with the wireless current receiver to correct the error that occurred during the K-estimation process, encompassing the full-mode error correction procedure: Entering a negotiation phase with errors; and Communicating the fault to the wireless power receiver; and In response to the determination that an error occurred during the K-estimation process and the wireless power receiver is unavailable to assist in correcting the error, the system performs a restricted-mode error correction procedure in which the wireless power transmitter attempts to correct the error that occurred during the K-estimation without cooperation from the wireless power receiver, including the restricted-mode error correction procedure: Removing the power signal, resetting the wireless power connection; Implementing one or more corrective actions; and Initiating another digital ping phase. [12] Wireless current transmitter according to claim 11, wherein determining that an error has occurred during the execution of the K-estimation is based on receiving an extended identification packet from a wireless current receiver containing a restricted field set to 1 for the restricted mode. [13] Wireless power transmitter according to claim 11, wherein one or more corrective measures include the control and communication circuit initiating a further digital ping at a second voltage level that differs from a first voltage level of the digital ping. [14] Wireless current transmitter according to claim 11, wherein communicating the fault to the wireless current receiver includes the control and communication circuit: Sending an unacknowledged (NAK) packet in response to a configuration packet (CFG packet) from the PRx; Sending an error packet (ERR packet) in response to a GET packet from the wireless power receiver. [15] Wireless power transmitter according to claim 11, wherein performing an error correction procedure in full mode further comprises: in response to receiving information from the wireless power receiver that enables the fault correction, completing the negotiation phase of the wireless power transmission, wherein the information enabling the fault correction is enclosed in an EPT / rst packet from the wireless power receiver, which is received by the control and communication circuit; and in response to the fact that no information is being received from the wireless power receiver that would allow the fault to be rectified: Receiving a request from the wireless power receiver to exit the negotiation phase; Removing the power signal, resetting the wireless power connection; Implementing one or more corrective actions; and Initiating another digital ping phase.

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