Uwb on / off operation method for minimizing power consumption and uwb anchor using the same

Abstract

A UWB anchor that minimizes power consumption using an ultra-wideband (UWB) on / off operation method. The UWB anchor includes a power supply that supplies power to the UWB anchor; a transceiver that transmits / receives a UWB signal to / from a UWB tag to perform ranging, and transmits a reception failure when the UWB signal cannot be received from the UWB tag; and a controller that receives the reception failure from the transceiver, and ends a ranging session when a cumulative sum of ranging failures per ranging block reaches a maximum number of ranging round attempts.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0110478, filed on August 20, 2021, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to an ultra-wideband (UWB) on / off operation method with minimized power consumption and a UWB anchor using the method, and more specifically to an ultra-wideband (UWB) on / off operation method with minimized power consumption by allowing the UWB anchor to be in a non-standby mode for UWB signal reception when the UWB anchor fails continuously in ranging and has a threshold number of failures. Background Technology

[0004] Ultra-wideband (UWB) is a wireless communication protocol that operates at high frequencies (6 GHz to 8 GHz) over a very wide bandwidth (i.e., over 500 MHz). Various functions such as location identification, location tracking, and remote payment can be performed using UWB. Specifically, UWB's advantage over conventional narrowband systems lies in its superior distance estimation accuracy. In ranging (or distance calculation) methods using UWB, time-of-flight (ToF) is a method that calculates the physical distance between communicating objects by multiplying the time it takes for signals to arrive between them by the speed of light.

[0005] UWB anchors act as responders in the ranging process of smart key / digital key systems. A UWB anchor can receive an initial signal (or pre-polling message) from a UWB tag acting as a UWB initiator (e.g., a smartphone equipped with a key card (fob) for a smart key or digital key system) and then respond to that message to complete its operation. However, it may not always be possible to operate all the multiple UWB anchors used in a smart key / digital key system. A UWB anchor may fail to receive UWB signals for various reasons, such as distance from the UWB tag (due to the characteristics of UWB wireless communication), lack of linearity, and material effects. In such cases, the UWB anchor may keep its receiving window open, which may result in unnecessary power consumption. Summary of the Invention

[0006] This summary is provided to describe in simplified form the selection of concepts further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help define the scope of the claimed subject matter.

[0007] Various embodiments relate to an ultra-wideband (UWB) on / off operation method that minimizes unnecessary power consumption and prevents UWB ranging performance degradation by ending a ranging session of a UWB anchor in a UWB signal reception non-standby mode when the UWB anchor continuously fails in ranging and has a set threshold number of failures, and allowing the UWB anchor to re-enter a UWB signal reception standby mode after a predetermined period of time, and a UWB anchor using the method.

[0008] Aspects of the present disclosure are not limited to the above-described aspects. That is, other aspects not mentioned can be clearly understood from the following description by those skilled in the art.

[0009] In one general aspect, a UWB anchor that minimizes power consumption using an ultra-wideband (UWB) on / off operation method includes a power supply configured to supply power to the UWB anchor; a transceiver configured to transmit / receive a UWB signal to / from a UWB tag to perform ranging, and transmit a reception failure when the UWB signal cannot be received from the UWB tag; and a controller configured to receive the reception failure from the transceiver, and end a ranging session when a cumulative sum of ranging failures for each ranging block reaches a maximum number of failure ranging round attempts.

[0010] The controller can be configured to control the UWB anchor to re-enter a UWB signal reception standby (or UWB on) mode when a UWB off time elapses, and the UWB off time can be set to be longer than a time of the UWB signal reception standby (or UWB on) mode.

[0011] In another general aspect, a smart key system that minimizes power consumption using a UWB on / off operation method includes a plurality of UWB anchors installed in a vehicle, each UWB anchor configured to calculate a distance between itself and a UWB tag by UWB communication and transmit the distance; and an integrated controller configured to calculate a position of the UWB tag by using the distances transmitted from the plurality of UWB anchors. Each UWB anchor is configured to end a UWB signal reception standby (or UWB on) mode to enter an idle (or UWB off) mode when a cumulative sum of ranging failures for each ranging block reaches a maximum number of failure ranging round attempts, and re-enter the UWB signal reception standby mode when a UWB off time elapses. The UWB off time is set to be longer than a time of the UWB signal reception standby (or UWB on) mode.

[0012] In another general aspect, a method of UWB on / off operation of an ultra-wideband (UWB) anchor for minimizing power consumption includes the UWB anchor entering a UWB signal reception standby (or UWB on) mode, determining whether ranging fails in each ranging block, accumulating a sum of the number of ranging failures when ranging continuously fails in more than one ranging block, checking whether the accumulated sum of the number of ranging failures reaches a maximum number of failed ranging round attempts, causing the UWB anchor to remain in a UWB signal reception non-standby (or UWB off) mode for a UWB off time when the accumulated sum of the number of ranging failures reaches the maximum number of failed ranging round attempts, and causing the UWB anchor to return to the UWB signal reception standby (or UWB on) mode when a preset UWB off time elapses, wherein the UWB off time is set to be longer than a time of the UWB signal reception standby (or UWB on) mode.

[0013] According to embodiments of the disclosure, unnecessary power consumption can be minimized by allowing the UWB anchor to no longer be in the UWB signal reception standby mode by setting a threshold for a case where the UWB anchor continuously fails in its ranging.

[0014] According to embodiments of the disclosure, the ranging performance of the UWB anchor can also be prevented from degrading by allowing the UWB anchor to re-enter the UWB signal reception standby mode (or to restart ranging) at a predetermined timing after the end of a ranging session.

[0015] Other features and aspects will become apparent from the following detailed description, drawings and claims. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a view illustrating a configuration for ultra-wideband (UWB) ranging according to an embodiment of the disclosure.

[0017] Figure 2 is a block diagram illustrating a configuration of a UWB anchor according to an embodiment of the disclosure.

[0018] Figure 3 is a reference diagram for explaining the concepts of a ranging block and a ranging round.

[0019] Figure 4 is a reference diagram illustrating a change in a current value in one ranging block when UWB ranging is successful.

[0020] Figure 5 is a reference diagram illustrating a change in a current value in one ranging block when UWB ranging continuously fails.

[0021] Figure 6 is a reference diagram illustrating a change in a current value when a maximum number of failed ranging round attempts is applied.

[0022] Figure 7 is a view illustrating an example of UWB on / off time setting of a UWB anchor according to an embodiment of the disclosure.

[0023] Figure 8A is a view illustrating another example of UWB on / off time setting of a UWB anchor according to an embodiment of the disclosure.

[0024] Figure 8B is a view illustrating yet another example of UWB on / off time setting of a UWB anchor according to an embodiment of the disclosure.

[0025] Figure 9 is a flowchart for explaining an example of a method of ultra wideband (UWB) on / off operation of a UWB anchor according to another embodiment of the disclosure.

[0026] Figure 10 is a block diagram for explaining a configuration of a smart key system according to yet another embodiment of the disclosure.

[0027] Figure 11 is a reference diagram for explaining calculation of an average moving speed of a UWB tag according to yet another embodiment of the disclosure.

[0028] Figure 12 is a flowchart for explaining another example of a method of UWB on / off operation of a UWB anchor according to another embodiment of the disclosure. DETAILED DESCRIPTION

[0029] The disclosure can be variously modified and have various embodiments, and specific embodiments will be illustrated in the accompanying drawings and described in detail in the detailed description. However, it should be understood that the disclosure is not limited to the specific embodiments, and includes all modifications, equivalents, and alternatives included within the spirit and scope of the disclosure. When it is determined that a detailed description of known technology related to the disclosure can obscure the subject matter of the disclosure, a detailed description thereof will be omitted.

[0030] The terms "first", "second", and the like used in the specification can be used to describe various components, and the components are not limited by the terms. Such terms are used only to distinguish one component from another component.

[0031] It will be understood that when a component is referred to as being "connected to" or "coupled to" another component, it can be directly connected or coupled to the other component or can be connected or coupled to the other component with a third component interposed therebetween. On the other hand, it will be understood that when a component is referred to as being "directly connected to" or "directly coupled to" another component, it can be connected or coupled to the other component without a third component interposed therebetween. Other expressions describing the relationship between components, i.e., "between," "directly between," "adjacent to," "directly adjacent to," etc., should be interpreted in a like fashion.

[0032] The term "...unit" described in the specification refers to a processing unit of at least one function or operation, and can be implemented by hardware or software or a combination of hardware and software.

[0033] The terms used in the specification are used only to describe specific embodiments, and are not intended to limit the disclosure. Unless explicitly indicated otherwise, singular forms can include plural forms. It will also be understood that the terms such as "include," "comprise," and the like used in the specification designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof mentioned in the specification, and do not exclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Hereinafter, embodiments of the disclosure are described in detail with reference to the accompanying drawings.

[0034] Figure 1 is a view illustrating a configuration for ultra-wideband (UWB) ranging according to an embodiment of the disclosure.

[0035] In an embodiment of the disclosure, the vehicle 10 can be installed with a plurality of UWB anchors 110, and the UWB anchors 110 can receive an initial signal transmitted from the UWB tag 200 and communicate with the UWB tag to perform ranging on the UWB tag 200. Here, the UWB tag 200 can serve as a UWB initiator, and the UWB anchor 110 can serve as a UWB responder. The UWB tag 200 can be a target of location tracking and refer to a wireless device that can perform UWB communication. For example, the UWB tag 200 can be a smart phone equipped with a key card operating in a smart key system or a digital key system.

[0036] Figure 2 is a block diagram illustrating a configuration of the UWB anchor 110 according to an embodiment of the disclosure.

[0037] As Figure 2 indicated, the UWB anchor 110 according to an embodiment of the disclosure can include a power supply unit 111, a transceiver unit 112, a control unit 113, and a vehicle network communication unit 114.

[0038] The power supply unit 111 can supply power to the UWB anchor 110 under the control of the control unit 113. For example, the power supply unit 111 can change the current value supplied to the UWB anchor 110 under the control of the control unit 113.

[0039] The transceiver 112 can receive an initial signal (or a pre-poll message) from the UWB tag 200 and transmit a response signal thereto, or can receive a final signal from the UWB tag 200. In addition, the transceiver 112 can transmit a report signal for distance data of the UWB tag 200 to the UWB tag 200. The transceiver 112 can transmit and receive other signals required for UWB ranging in addition to the above-mentioned signals to and from the UWB tag 200. The transceiver unit 112 can not be able to receive a signal from the UWB tag 200 within a ranging round, and thus can not perform ranging. In this case, the transmitter 112 can transmit this failure to the control unit 113, so that the control unit 113 accumulates and sums up the ranging failure for each ranging block, and performs a UWB ON / OFF operation when the ranging failure. The ranging failure refers to a case in which the transceiver unit 112 is not able to receive a signal from the UWB tag 200 and thus is not able to calculate a distance between the UWB anchor 110 and the UWB tag 200. The ranging failure can include a case in which the distance is not able to be calculated due to the fact that the transceiver unit 112 is not only not able to receive an initial signal from the UWB tag 200 but also not able to receive a subsequent signal thereof.

[0040] When the ranging failure occurs, the transceiver 112 can turn off a reception window based on UWB OFF control of the control unit 113. In addition, the transceiver unit 112 can transmit information in a final signal transmitted by the UWB tag 200, i.e., information about an identification (ID) of the UWB tag 200 and UWB signal transmission / reception timing, and information about reception timing of the final signal, to the control unit 113 to allow the control unit 113 to calculate a distance.

[0041] When the ranging failure is received from the transceiver unit 112, the control unit 113 can accumulate sum the ranging failure for each ranging block and check whether the accumulated sum reaches the maximum number of failed ranging round attempts MAX_RR_RETRY. When the continuous accumulated sum of the ranging failure for each ranging block reaches the maximum number of failed ranging round attempts, the control unit 113 can apply a preset UWB shutdown time. The control unit 113 can end the ranging session (i.e., start the UWB shutdown mode) to reduce power consumption. That is, the control unit 113 can control the transceiver unit 112 to shut down the reception window and control the power supply unit 111 to conduct only a predetermined current value. The control unit 113 can control the UWB shutdown time based on the number of predetermined ranging blocks or time. That is, when a set number of ranging blocks or time elapses, the control unit 113 can allow the ranging to be attempted again (i.e., re-enter the UWB signal reception accumulation standby (or UWB on) mode). Meanwhile, when the transceiver unit 112 normally receives information related to signal transmission / reception with the UWB tag 200, the control unit 113 can calculate the distance between the UWB tag 200 and the UWB anchor 110.

[0042] The vehicle network communication unit 114 can transmit and receive signals to and from the integrated controller of the smart key system through a communication bus in the vehicle. When the continuous accumulated sum of the ranging failure for each ranging block reaches the maximum number of failed ranging round attempts, the control unit 113 can allow the corresponding information to be transmitted to the integrated controller through the vehicle network communication unit 114.

[0043] Figures 3 to 5 is a reference diagram for comparing and explaining power consumption when the UWB anchor succeeds and fails in ranging.

[0044] Figure 3 is a reference diagram for explaining the concept of a ranging block and a ranging round.

[0045] A ranging block refers to a unit of time for performing ranging. The ranging block can include a plurality of ranging rounds. Figure 3 An example in which one ranging block includes 8 ranging rounds is illustrated, and the number of ranging rounds included in the ranging block can be changed. Figure 3 An example of processing eight ranging blocks along a time axis is shown.

[0046] A ranging round refers to a unit of one complete ranging event performed between an initiator and a responder on a UWB network. Figure 3 An example in which one ranging block includes eight ranging rounds is shown.

[0047] Figure 4is a reference graph illustrating a change in current value in one ranging block when UWB ranging is successful.

[0048] The actual current value can depend on detailed operations of the UWB transmitter and receiver. However, for ease of description of the concept, it can be assumed that the current value needs to be maintained at a maximum value (and Figures 4 to 6 The current value indicated in the graph in is an approximate value.

[0049] When ranging is successful in the first ranging round, ranging is no longer performed in the other ranging rounds defined as one ranging block. Accordingly, the current can be maintained at a level lower (e.g., 1 / 4) than the current required for ranging in the other ranging rounds.

[0050] Figure 5 is a reference graph illustrating a change in current value in one ranging block when UWB ranging is continuously failed.

[0051] Although the UWB anchor 110 continuously fails ranging from the first ranging round to the last ranging round, the UWB anchor 110 can need to keep the reception window open to receive an initial signal (or a pre-poll message) from the UWB tag 200. As a result, a higher current (e.g., four times higher current) can need to be continuously maintained in the corresponding ranging block compared to the current when ranging is not performed, and thus a large amount of power can be unnecessarily consumed compared to the case of Figure 4 .

[0052] Figure 6 is a reference graph illustrating a change in current value when the maximum number of failed ranging round attempts is applied.

[0053] The maximum number of failed ranging round attempts MAX_RR_RETRY can be designated in response to the above power consumption problem. When the number of ranging blocks in which ranging fails reaches the designated number, the ranging session can be ended. For example, when the maximum number of failed ranging round attempts is designated as five (5) as illustrated in the graph, ranging can be attempted in five ranging blocks, and then the ranging session can be ended. However, power consumption needs to be reduced while ensuring ranging performance, and thus timing for restarting the ranging process needs to be considered.

[0054] According to embodiments of the disclosure, one UWB anchor 110 can be in a UWB on (or UWB signal reception standby) mode or a UWB off (or idle) mode. The UWB signal reception standby mode refers to a mode in which the UWB anchor 110 opens a reception window even in a case where the UWB anchor 110 succeeds in ranging or fails in ranging the UWB tag 200 when the number of attempts of the UWB anchor 110 has not reached a predetermined maximum number of failed ranging round attempts. When the UWB anchor 110 continuously fails in ranging the UWB tag 200, the accumulated number of failures can increase. The accumulated number of failures can be cumulatively summed one by one by determining whether each ranging block fails in ranging, and can be zero (0) when ranging succeeds. When the accumulated number of failures reaches the predetermined maximum number of failed ranging round attempts, the UWB anchor 110 can switch to the idle mode (i.e., a state in which the reception window is not opened) to reduce power consumption. The control unit 113 can control the power supply unit 111 and the transceiver unit 112 based on a preset UWB off time or the number of ranging blocks in the UWB off mode. During the idle mode, the transceiver unit 112 can not open the reception window under the control of the control unit 113, and the current flowing from the power supply unit 111 can be reduced compared to the current flowing in the UWB on mode. For example, 100 mA of current can flow in the UWB signal reception standby mode, and 0.1 mA of current can flow in the idle mode.

[0055] The following description refers to Figure 7 An example of UWB on / off time setting of the UWB anchor 110 according to embodiments of the disclosure is described. The time setting can repeat the UWB on / off at the same period, and the UWB off time can be equal to a time calculated by the maximum number of failed ranging round attempts MAX_RR_RETRY.

[0056] For example, when the maximum number of failed ranging round attempts is five (5) and the ranging block is 192 ms, the UWB on time can be 960 ms by multiplying 192 ms by five (5), and the UWB off time can be the same 960 ms. Thus, the UWB on / off can be repeated once every 960 ms.

[0057] This strategy can reduce the power consumption of the UWB anchor by half and prevent ranging performance degradation by setting the UWB ranging restart (or return) timing based on the maximum number of failed ranging round attempts.

[0058] Meanwhile, ranging performance can be improved by making the UWB off time shorter than the UWB on time in the UWB on / off time setting of the UWB anchor 110 according to embodiments of the disclosure.

[0059] The following description refers toFigure 8A Another example of UWB on / off time setting of the UWB anchor 110 according to embodiments of the disclosure is described. In this time setting, the UWB off time can be set to a constant time regardless of the maximum number of failed ranging round attempts. For example, when the ranging block (B) is 192 ms and the maximum number of failed ranging round attempts is five (5), the UWB on time can be 960 ms by multiplying 192 ms by five (5), and the UWB off time can be four times the UWB on time when the UWB off time is set to 3840 ms.

[0060] The following description refers to Figure 8B Yet another example of UWB on / off time setting is described. For example, when the ranging block is 384 ms and the maximum number of failed ranging round attempts is three (3), the UWB on time can be 1152 ms by multiplying 384 ms by three (3), and the UWB off time can be 3.33 times the UWB on time when the UWB off time is 3840 ms.

[0061] The above-described time settings can greatly reduce the power consumption of the UWB anchor.

[0062] Yet another example of UWB on / off time setting of the UWB anchor according to embodiments of the disclosure is a method of increasing the UWB off time by a predetermined unit from an initially designated time when the corresponding UWB anchor continuously fails ranging during the UWB on time. For example, when the ranging block is 192 ms and the maximum number of failed ranging round attempts is five (5), the UWB on time can be 960 ms by multiplying 192 ms by five (5). The initial UWB off time can be set to 3840 ms, and the increment can be set to 192 ms, which is the ranging block time. The initial UWB off time can be four times the UWB on time. However, when ranging fails during the next UWB on time, the UWB off time can be 4.2 times the UWB on time (i.e., 4032 ms), and when ranging fails during the next UWB on time, the UWB off time can become 4.4 times the UWB on time (i.e., 4224 ms). This method can greatly reduce the power consumption of the UWB anchor.

[0063] Figure 9 is a flowchart for explaining a method of ultra-wideband (UWB) on / off operation of a UWB anchor according to another embodiment of the disclosure.

[0064] First, in operation S110, the UWB anchor 110 can enter a UWB on (or UWB signal reception standby) mode, the transceiver unit 112 can open a reception window under the control of the control unit 113, and the power supply unit 111 can conduct a current sufficient to receive a UWB signal from the UWB tag 200.

[0065] In operation S120, it can be determined whether ranging fails in each ranging block. That is, when the transceiver unit 112 fails to receive a signal from the UWB tag 200 within a ranging round and thus fails to perform ranging, the transceiver unit 112 can transmit the failure to the control unit 113, so that the control unit 113 accumulatively sums ranging failures for each ranging block. When ranging fails in all ranging rounds in a corresponding ranging block, the control unit 113 can determine that ranging fails in the corresponding ranging block.

[0066] In operation S130, the number of consecutive ranging failures can be accumulatively summed. For example, when ranging fails in a previous ranging block and ranging fails in a next ranging block, the number of consecutive ranging failures can be two (2).

[0067] In operation S140, it can be determined whether the number of consecutive ranging failures reaches a predetermined maximum number of failed ranging round attempts, when the number of consecutive ranging failures does not reach the maximum number of failed ranging round attempts, the operation can return to operation S120 to determine whether ranging consecutively fails in each ranging block, and when the number of consecutive ranging failures reaches the maximum number of failed ranging round attempts, the mode can be switched to a UWB off (or idle) mode.

[0068] In operation S180, the reception window can not be opened (i.e., the idle mode can be maintained) for a set UWB off time (or a number of ranging blocks). When the set UWB off time (or a number of ranging blocks) elapses, the control unit 113 can control the mode to return to the UWB on (or UWB signal reception standby) mode and start ranging again (S110).

[0069] Figure 10 is a block diagram for explaining a configuration of a smart key system according to still another embodiment of the disclosure.

[0070] As Figure 10 shown, a smart key system 100 according to still another embodiment of the disclosure can include a plurality of UWB anchors 110-1 to 110-n and an integrated controller 120. The functions of the UWB anchors 110 and the components included in the UWB anchors 110 can be substantially the same as those described with reference to Figure 2 the first embodiment.

[0071] Each UWB anchor (i.e., one of 110-1 to 110-n, hereinafter referred to as 110) can calculate a distance between itself and the UWB tag 200 and transmit the calculated distance to the vehicle network communication unit 122 of the integrated controller 120 through the built-in vehicle network communication unit 114.

[0072] The vehicle network communication unit 122 of the integrated controller 120 can transmit the calculated distance data to the ranging unit 121. The ranging unit 121 can estimate the position of the UWB tag 200 based on the distance data. The position of the UWB tag can be estimated using a known triangulation method.

[0073] As described above, the control unit 113 of each UWB anchor 110 can accumulate a sum of the number of ranging failures for each ranging block. When the number reaches the maximum number of failed ranging round attempts, the control unit 113 can allow the information to be transmitted to the vehicle network communication unit 122 of the integrated controller 120 along with its identification (ID) through the vehicle network communication unit 114. In this case, the vehicle network communication unit 122 of the integrated controller 120 can transmit the information to the ranging unit 121.

[0074] The ranging unit 121 can store the movement path data (or time and position) of the UWB tag 200 for a predetermined time period and calculate the average movement speed and movement direction of the UWB tag 200 for the predetermined time period using the data. The average movement speed calculated by the ranging unit 121 refers to the speed at which the UWB tag 200 moves away from a specific position of the vehicle (e.g., the center of gravity of the vehicle) for the predetermined time period (see the detailed description below and Figure 11 ). The ranging unit 121 can store the movement path data (time and position) of the UWB tag 200 for a predetermined time period and calculate the speed and direction of the UWB tag 200. The ranging unit 121 can transmit, through the vehicle network communication unit 122, the average movement speed, the movement direction, the distance from the specific position of the vehicle to the final measured position of the UWB tag 200, or the final measured position of the UWB tag 200 within the most recent predetermined time range to the UWB anchor 110 having the maximum number of failed ranging round attempts.

[0075] The control unit 113 of the UWB anchor 110 can determine the UWB off time based on information received through the vehicle network communication unit 114. For example, the control unit 113 can set a threshold value of the average moving speed, and control the change in the UWB on / off time setting based on whether the average moving speed exceeds the threshold value. For example, when the average moving speed of the UWB tag 200 exceeds 0.5 m / sec, the control unit 113 can determine to minimize power consumption by controlling the UWB off time of the UWB anchor 110 to be longer than the UWB on time. On the other hand, when the average moving speed of the UWB tag 200 is 0.5 m / sec or less, the control unit 113 can determine to ensure constant ranging performance by controlling the UWB off time of the UWB anchor 110 to be equal to the UWB on time. Also, when a threshold value of the distance from a specific location of the vehicle to the UWB tag 200 is designated, the control unit 113 can control the change in the UWB off time based on whether the corresponding distance exceeds the threshold value. For example, the threshold value of the distance can be 20 m. In this case, when the distance exceeds the threshold value, the control unit 113 can determine to minimize power consumption by controlling the UWB off time to be longer than the UWB on time. On the other hand, when the distance is within 20 m, the control unit 113 can determine to ensure constant ranging performance by controlling the UWB off time to be equal to the UWB on time. Also, the control unit 113 can control the change in the UWB off time based on whether the final measured position of the UWB tag 200 is close to the UWB anchor 110. For example, when the final measured position of the UWB tag 200 is close to the UWB anchor 110, the control unit 113 can determine to control the UWB off time to be equal to the UWB on time, and when the final measured position of the UWB tag 200 is far from the UWB anchor 110, the control unit 113 can determine to control the UWB off time to be longer than the UWB on time. In detail, for example, the UWB anchor 110 can be installed at the front of the vehicle. In this case, when the final measured position of the UWB tag 200 is in front of the vehicle, the control unit 113 can control the UWB on time to be equal to the UWB off time, and when the position of the UWB tag 200 is behind the vehicle, the control unit 113 can control the UWB off time to be longer than the UWB on time.

[0076] The following description describes the calculation of the average moving speed of the UWB tag 200 according to still another embodiment of the disclosure.

[0077] The average moving speed calculated by the ranging unit 121 refers to a speed at which the UWB tag 200 moves away from a specific location of the vehicle (e.g., the center of gravity of the vehicle) for a predetermined time period. For example, the initial distance from the center of gravity of the vehicle to the UWB tag 200 can be 10 m, and at a timing from which 10 seconds elapses, the distance from the center of gravity of the vehicle to the UWB tag 200 can be 15 m. In this case, the average moving speed of the UWB tag 200 for 10 seconds can be 0.5 m / sec, which is obtained by dividing (15 m - 10 m) by 10 seconds. In the illustrated graph, the X-axis indicates time, and the Y-axis indicates the distance from the specific location of the vehicle to the UWB tag 200. The predetermined time (Δt) before the calculation timing can be the start point of the time interval, and the calculation timing can be the end point of the time interval. In this case, the average moving speed of the UWB tag 200 at the calculation timing obtained by the ranging unit 121 can have a value obtained by dividing the difference (Δs) between the distance from the specific location of the vehicle to the UWB tag 200 at the start timing and the distance from the specific location of the vehicle to the UWB tag 200 at the end point by the predetermined time (Δt).

[0078] Figure 12 is a flowchart for explaining another example of a UWB on / off operation method of a UWB anchor according to another embodiment of the disclosure.

[0079] The descriptions of operations S110 to S130 and S180 are the same as those described with reference to Figure 9 the operations described with reference to

[0080] In operation S140, it can be determined whether the number of consecutive ranging failures reaches a predetermined maximum number of failed ranging round attempts, when the number does not reach the maximum number of failed ranging round attempts, the operation can return to operation S120 to determine whether each ranging block ranges continuously fails, and when the number reaches the maximum number of failed ranging round attempts, operation S160 can be performed.

[0081] In operation S160, the ranging unit 121 of the integrated controller 120 can calculate the average moving speed of the UWB tag 200 with respect to the recent moving path of the UWB tag 200. In addition, the ranging unit 121 of the integrated controller 120 can determine the recent average moving direction of the UWB tag 200 based on the moving path data of the UWB tag 200. The time range for calculating the average moving speed and the average moving direction can have a predetermined specific value (e.g., 10 seconds).

[0082] In operation S170, the ranging unit 121 of the integrated controller 120 can transmit the average moving speed of the UWB tag 200 to the UWB anchor 110 for which the number of consecutive ranging failures reaches the maximum number of failure ranging rounds attempts, through the vehicle network communication unit 122. In addition, the ranging unit 121 can transmit the average moving direction of the UWB tag 200 or the distance from a specific location of the vehicle to the finally measured location of the UWB tag 200, instead of the average moving speed of the UWB tag 200. The control unit 113 of the UWB anchor 110 can determine the UWB off time based on at least one of the average moving speed, the average moving direction, and the finally measured distance to the location of the UWB tag 200.

[0083] By way of reference, components according to embodiments of the present disclosure can be implemented in the form of software or hardware (e.g., a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC)), and perform a specific role.

[0084] However, the meaning of "component" is not limited to software or hardware, and each of the components can be configured to reside in an addressable storage medium and reproduce one or more processors.

[0085] Accordingly, by way of example, a component includes components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables.

[0086] Components and functions provided by the corresponding components can be combined into a smaller number of components or can be further divided into additional components.

[0087] The term "…unit" used in embodiments of the present disclosure refers to a software component or a hardware component such as an FPGA or an ASIC, and performs a predetermined role. However, it should be understood that the term "…unit" is not limited to a software or hardware component. The "…unit" can be configured to reside in an addressable storage medium or reproduce one or more processors. Accordingly, by way of example, the "…unit" includes components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Components and functions provided by these components can be combined into a smaller number of components or can be further divided into additional components. The "…unit" and the functions provided by the "…unit" can be combined into a smaller number of components and "…units" or can be further divided into additional components and additional "…units". Furthermore, the components and "…units" can be implemented to reproduce one or more CPUs in a device or a secure multimedia card.

[0088] While the disclosure has been described above with reference to examples, it will be appreciated that those skilled in the art will be able to devise various modifications and alternatives to the examples without departing from the spirit and scope of the disclosure as defined in the appended claims.

Claims

1.An ultra-wideband (UWB) anchor for minimizing power consumption using a UWB on / off operation method, the UWB anchor comprising: a power supply configured to supply power to the UWB anchor; a transceiver configured to transmit / receive a UWB signal to / from a UWB tag to perform ranging, and transmit a reception failure when a UWB signal cannot be received from the UWB tag; and a controller configured to receive the reception failure from the transceiver, and end a ranging session and a UWB signal reception standby mode or a UWB on mode to enter an idle mode or a UWB off mode when a sum of accumulations of ranging failures for each ranging block reaches a maximum number of ranging failure round attempts in consecutive ranging blocks, wherein each ranging block includes a plurality of ranging rounds, wherein the controller is configured to determine whether ranging fails for each ranging block, wherein ranging fails in a ranging block when ranging fails in all ranging rounds of a corresponding ranging block, wherein the controller is configured to control the UWB anchor to re-enter the UWB signal reception standby mode or the UWB on mode when a UWB off time elapses, and the UWB off time is set to be longer than a time of the UWB signal reception standby mode or the UWB on mode. 2.An intelligent key system for minimizing power consumption using a UWB on / off operation method, the intelligent key system comprising: a plurality of UWB anchors installed in a vehicle, each UWB anchor configured to calculate a distance between itself and a UWB tag by UWB communication and transmit the distance; and an integrated controller configured to calculate a position of the UWB tag by using the distances transmitted from the plurality of UWB anchors, wherein each UWB anchor is configured to end a ranging session and a UWB signal reception standby mode or a UWB on mode to enter an idle mode or a UWB off mode when a sum of accumulations of ranging failures for each ranging block reaches a maximum number of ranging failure round attempts in consecutive ranging blocks, and re-enter the UWB signal reception standby mode when a UWB off time elapses, wherein each ranging block includes a plurality of ranging rounds, wherein the integrated controller is configured to determine whether ranging fails for each ranging block, wherein ranging fails in a ranging block when ranging fails in all ranging rounds of a corresponding ranging block, and the UWB off time is set to be longer than a time of the UWB signal reception standby mode or the UWB on mode. 3.A UWB on / off operation method for minimizing power consumption of an ultra-wideband (UWB) anchor, the UWB on / off operation method comprising: a UWB anchor entering a UWB signal reception standby mode or a UWB on mode; determining whether ranging fails for each ranging block, wherein each ranging block includes a plurality of ranging rounds, wherein ranging fails in a ranging block when ranging fails in all ranging rounds of a corresponding ranging block; a controller accumulating a sum of a number of times ranging fails when ranging consecutively fails in more than one ranging block; ​ checking whether a cumulative sum of a number of times of ranging failure reaches a maximum number of failed ranging round attempts; when the cumulative sum of the number of times of ranging failure in consecutive ranging blocks reaches the maximum number of failed ranging round attempts, causing the UWB anchor to be maintained in a UWB signal reception non-standby mode or a UWB off mode for a UWB off time; and when a preset UWB off time elapses, causing the UWB anchor to return to the UWB signal reception standby mode or the UWB on mode, wherein the UWB off time is set to be longer than a time of the UWB signal reception standby mode or the UWB on mode.

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