Patent Publication Number: US-2023161403-A1

Title: Method for managing tracking sensors, tracking device, and computer readable storage medium

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of U.S. provisional application Ser. No. 63/281,740, filed on Nov. 22, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present disclosure generally relates to a tracking mechanism, in particular, to a method for managing tracking sensors, a tracking device, and a computer readable storage medium. 
     2. Description of Related Art 
     See  FIG.  1 A  and  FIG.  1 B , which show the appearance of head-mounted displays (HMD) disposed with tracking sensors. In  FIG.  1 A , the HMD  101  has several tracking sensors disposed at the positions labelled with circles, wherein the tracking sensors on the HMD  101  can be cameras used to capture images of the environment where the HMD  101  locates. In this case, the HMD  101  can perform, for example, an inside-out tracking mechanism to track the pose of the HMD  101  based on the images captured by the cameras. 
     In  FIG.  1 B , the HMD  102  also has several tracking sensors disposed at the positions labelled with circles, wherein the tracking sensors on the HMD  102  can be beacon sensors that receives beacons emitted from one or more external beacon source (e.g., a base station of a virtual reality (VR) system). In this case, the HMD  102  can perform, for example, an outside-in tracking mechanism to track the pose of the HMD  102  based on the received beacons. 
     Although the tracking accuracy can be improved by disposing more tracking sensors on a tracking device (e.g., the HMD of a VR system), more power would be consumed as well. The power consumption would be increased when using tracking sensor with high frequency/resolution. 
     In addition, more tracking sensors means more data flow would be inputted to the processor of the tracking device, which not only occupies computation resource but also consumes lots of power, which induces more heat and less battery life. In order to reduce the heat, some cooling mechanism (e.g., a fan) has to be disposed within the tracking devices, which would increase the weight of the tracking devices. 
     Since the design of the tracking devices (e.g., the HMD) tends to be smaller and lighter, it is crucial to develop a better design of tracking devices to reduce the power consumption and heat. 
     SUMMARY OF THE INVENTION 
     Accordingly, the disclosure is directed to a method for managing tracking sensors, a tracking device, and a computer readable storage medium, which may be used to solve the above technical problems. 
     The embodiments of the disclosure provide a method for managing tracking sensors, adapted to a tracking device having a plurality of tracking sensors. The method includes: obtaining a first sensing data of a first tracking sensor of the tracking sensors; determining a first sensing result of a first tracking sensor of the tracking sensors; and in response to the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to an untrackable status, decreasing a first sensing rate of the first tracking sensor. 
     The embodiments of the disclosure provide a tracking device including a plurality of tracking sensors, a storage circuit, and a processor. The storage circuit stores a program code. The processor is coupled to the tracking sensors and the storage circuit, and accesses the program code to perform: obtaining a first sensing data of a first tracking sensor of the tracking sensors; determining a first sensing result of a first tracking sensor of the tracking sensors; in response to the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to an untrackable status, decreasing a first sensing rate of the first tracking sensor. 
     The embodiments of the disclosure provide a non-transitory computer readable storage medium, the computer readable storage medium recording an executable computer program, the executable computer program being loaded by a tracking device to perform steps of: obtaining a first sensing data of a first tracking sensor of the tracking sensors; determining a first sensing result of a first tracking sensor of the tracking sensors; and in response to the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to an untrackable status, decreasing a first sensing rate of the first tracking sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the disclosure. 
         FIG.  1 A  and  FIG.  1 B  show the appearance of head-mounted displays (HMD) disposed with tracking sensors. 
         FIG.  2    shows a schematic diagram of a tracking device according to an embodiment of the disclosure. 
         FIG.  3    shows schematic diagrams of an environment where the tracking device locates according to an embodiment of the disclosure. 
         FIG.  4    shows a flow chart of the method managing tracking sensors according to an embodiment of the disclosure. 
         FIG.  5    shows a schematic diagram of the sensing rate adjustment of several tracking sensors according to an embodiment of the disclosure. 
         FIG.  6    shows a schematic diagram of the sensing rate adjustment of several tracking sensors according to an embodiment of the disclosure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     See  FIG.  2   , which shows a schematic diagram of a tracking device according to an embodiment of the disclosure. In various embodiments, the tracking device  200  can be any device that is capable of performing tracking functions (e.g., inside-out tracking and/or outside-in tracking), such as one or a combination of a handheld controller (e.g., a VR handheld controller), a HMD, and a tracker. In one embodiment, the tracker can be an accessory of the VR system, wherein the tracker can be attached to any to-be-tracked object for other device (e.g., the HMD) to track, but the disclosure is not limited thereto. 
     In  FIG.  2   , the tracking device  200  includes a storage circuit  202 , a processor  204 , and a plurality of tracking sensors  2061 - 206 N. The storage circuit  202  is one or a combination of a stationary or mobile random access memory (RAM), read-only memory (ROM), flash memory, hard disk, or any other similar device, and which records a plurality of modules that can be executed by the processor  204 . 
     The processor  204  may be coupled with the storage circuit  202  and the tracking sensors  2061 - 206 N, and the processor  104  may be, for example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. 
     In a first embodiment, the tracking device  200  is implemented as the HMD  101  in  FIG.  1 A . In this case, the tracking sensors  2061 - 206 N can be the cameras disposed on the tracking device  200  and used for capturing images of the environment where the tracking device  200  locates. For example, for a first tracking sensor (e.g., the tracking sensor  2061 ) of the tracking sensors  2061 - 206 N, the processor  204  can control the first tracking sensor to capture a plurality of images of the environment and detect a plurality of environmental landmarks in each image. In the embodiments of the disclosure, the term “environmental landmark” can be generally understood as, including but not limited to, features, or any trackable objects in each image. Next, the processor  204  can determine the pose of the tracking device  200  corresponding to each image based the environmental landmarks in each image. 
     In one embodiment, the processor  204  can perform the mechanisms of detecting environmental landmarks and determining poses based on Simultaneous localization and mapping (SLAM), but the disclosure is not limited thereto. 
     In one embodiment, for a first image among the images captured by the first tracking sensor, the processor  204  can determine a plurality of first environmental landmarks in the first image as a first sensing result of the first tracking sensor. In this case, the processor  204  can determine whether a number of the first environmental landmarks in the first image is less than an amount threshold. In one embodiment, the amount threshold can be a number of environmental landmarks enough for the processor  204  to accordingly determine the pose of the tracking device  200 , but the disclosure is not limited thereto. 
     In one embodiment, in response to determining that the number of the first environmental landmarks in the first image is less than the amount threshold, the processor  204  can determine that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the untrackable status. Specifically, if the number of the first environmental landmarks in the first image is less than the amount threshold, it represents that the processor  204  may not be able to perform tracking based on the first environmental landmarks in the first image. 
     See  FIG.  3   , which shows schematic diagrams of an environment where the tracking device locates according to an embodiment of the disclosure. In  FIG.  3   , assuming that the environment  300  is the place where the tracking device  200  locates. In this cases, if the viewpoint of the first tracking senor faces a place without or with only a few landmarks, (e.g., a white wall  301 ), there may not be many first environmental landmarks in the first image captured by the first tracking sensor. In this case, the processor  204  cannot track the pose of the tracking device  200  based on the first environmental landmarks in the first image, and hence the processor  204  can determine that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the untrackable status. 
     On the other hand, in response to determining that the number of the first environmental landmarks in the first image is not less than the amount threshold, the processor  204  can determine that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to a trackable status. Specifically, if the number of the first environmental landmarks in the first image is not less than the amount threshold, it represents that the processor  204  is able to perform tracking based on the first environmental landmarks in the first image. For example, if the viewpoint of the first tracking senor faces a place with lots of features (e.g., an area  302  where one or more pieces of furniture locate), there may be many first environmental landmarks in the first image captured by the first tracking sensor. In this case, the processor  204  can track the pose of the tracking device  200  based on the first environmental landmarks in the first image, and hence the processor  204  can determine that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the trackable status. 
     In a second embodiment, the tracking device  200  is implemented as the HMD  102  in  FIG.  1 B . In this case, the tracking sensors  2061 - 206 N can be the beacon sensors disposed on the tracking device  200  and used for receiving beacons from one or more external beacon source in the environment where the tracking device  200  locates. In one embodiment, the beacons can be laser lights emitted from the external beacon sources (e.g., base stations of the VR system). For example, for a first tracking sensor (e.g., the tracking sensor  2061 ) of the tracking sensors  2061 - 206 N, the processor  204  can control the first tracking sensor to receive one or more beacons from the external beacon sources. Next, the processor  204  can determine the pose of the tracking device  200  based on the received beacons via performing the outside-in tracking function (e.g., the light house tracking mechanism), but the disclosure is not limited thereto. 
     In one embodiment, the processor  204  can determine the beacons received by the first tracking sensor as a first sensing result of the first tracking sensor. In this case, the processor  204  can determine whether a number of the beacons received by the first tracking sensor is less than an amount threshold. In one embodiment, the amount threshold can be a number of beacons enough for the processor  204  to accordingly determine the pose of the tracking device  200 , but the disclosure is not limited thereto. 
     In one embodiment, in response to determining that the number of the beacons received by the first tracking sensor is less than the amount threshold, the processor  204  can determine that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the untrackable status. Specifically, if the number of the beacons received by the first tracking sensor is less than the amount threshold, it represents that the processor  204  may not be able to perform tracking based on the beacons received by the first tracking sensor. For example, if the pose of the tracking device  200  makes the first tracking sensor unable to receive enough beacons (e.g., the first tracking sensor being occluded), the processor  204  cannot track the pose of the tracking device  200  based on the beacons received by the first tracking sensor, and hence the processor  204  can determine that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the untrackable status. 
     On the other hand, in response to determining that the number of the beacons received by the first tracking sensor is not less than the amount threshold, the processor  204  can determine that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to a trackable status. Specifically, if the number of the beacons received by the first tracking sensor is not less than the amount threshold, it represents that the processor  204  is able to perform tracking based on the beacons received by the first tracking sensor. For example, if the pose of the tracking device  200  makes the first tracking sensor able to receive enough beacons (e.g., the first tracking sensor being not occluded), the processor  204  can track the pose of the tracking device  200  based on the beacons received by the first tracking sensor, and hence the processor  204  can determine that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the trackable status. 
     In other embodiments, a part of the tracking sensors  2061 - 206 N can be implemented as the cameras of the first embodiment, and another part of the tracking sensors  2061 - 206 N can be implemented as the beacon sensors of the second embodiment, such that the tracking sensor  200  can perform the inside-out tracking and the outside-in tracking based on the teachings in the first embodiment and the second embodiment, but the disclosure is not limited thereto. 
     In some embodiments, the tracking sensors  2061 - 206 N can be also implemented as other kind of sensors whose sensing result and/or sensing data can be used by the processor  204  for determining the pose of the tracking device  200 . In this case, one tracking sensor would be regarded as corresponding to the untrackable status when the processor  204  determines that the sensing result and/or sensing data provided by this tracking sensor is not enough for the processor  204  to track the pose of the tracking device  200 . On the other hand, one tracking sensor would be regarded as corresponding to the trackable status when the processor  204  determines that the sensing result and/or sensing data provided by this tracking sensor is enough for the processor  204  to track the pose of the tracking device  200 , but the disclosure is not limited thereto. 
     In some embodiments, the tracking sensors  2061 - 206 N can be also implemented as other kind of sensors whose sensing result and/or sensing data can be used by the processor  204  for determining the pose of the tracking device  200 . In this case, one tracking sensor would be regarded as corresponding to the untrackable status when the processor  204  determines that the tracking quality, the tracking confidence, and/or the viewpoint of this tracking sensor is unqualified for the processor  204  to track the pose of the tracking device  200 . On the other hand, one tracking sensor would be regarded as corresponding to the trackable status when the processor  204  determines that the tracking quality, the tracking confidence, and/or the viewpoint of this tracking sensor is qualified for the processor  204  to track the pose of the tracking device  200 , but the disclosure is not limited thereto. 
     In the embodiments of the disclosure, each of the tracking sensors  2061 - 206 N has its own sensing rate. Taking the aforementioned first tracking sensor as an example, the first tracking sensor has a first sensing rate for providing the corresponding sensing result and/or sensing data. 
     In the first embodiment where the first tracking sensor is a camera, the first sensing rate can be the corresponding frame rate of the first tracking sensor. For example, when the first sensing rate is K frame per second (fps), the first tracking sensor would capture one image every 1/K second, wherein K can be 30, 60, 90, etc. 
     In the second embodiment where the first tracking sensor is a beacon receiver, the first sensing rate can be the rate of the first tracking sensor being triggered to receive beacons. For example, when the first sensing rate is K times per second (fps), the first tracking sensor would be triggered to receive the beacons every 1/K second, wherein K can be desired values of the designer etc. 
     In the embodiments of the disclosure, the sensing rate of each of the tracking sensors  2061 - 206 N can be adaptively adjusted based on the corresponding sensing result, such that the power consumption of the tracking device  200  can be reduced. 
     In the embodiments of the disclosure, the processor  204  can access the modules stored in the storage circuit  202  to implement the method for managing tracking sensors provided in the disclosure, which would be further discussed in the following. 
     See  FIG.  4   , which shows a flow chart of the method managing tracking sensors according to an embodiment of the disclosure. The method of this embodiment may be executed by the tracking device  200  in  FIG.  2   , and the details of each step in  FIG.  4    will be described below with the components shown in  FIG.  2   . In addition, the first tracking sensor would be used as an example for better explaining the concept of the disclosure, and the operations corresponding to other tracking sensors can be understood based on the teachings in the following. 
     In step S 410 , the processor  204  obtain a first sensing data of a first tracking sensor of the tracking sensors. In various embodiments, the first sensing data can include any data sensed by the first tracking sensor. 
     In step S 420 , the processor  204  obtains the first sensing result of the first tracking sensor. In various embodiments, the first sensing result of the first tracking sensor can be obtained based on the teachings in the above embodiments, which would not be repeated herein. 
     In some embodiments, the first sensing result determined based on the first sensing data can also be characterized by the tracking quality of the first tracking sensor, the tracking confidence of the first tracking sensor, and/or the viewpoint of the first tracking sensor, but the disclosure is not limited thereto. The mechanisms for determining the tracking quality, the tracking confidence, and/or the viewpoint based on the first sensing data can be referred to the related prior arts. 
     In one embodiment, the processor  204  can determine whether the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the untrackable status. If the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the trackable status, it represents that the sensing result and/or sensing data provided by the first tracking sensor is enough for the processor  204  to track the pose of the tracking device  200 . In this case, the processor  204  can maintain the first sensing rate of the first tracking sensor, such that the first tracking sensor can continuously provide useful information for the processor  204  to perform pose tracking, but the disclosure is not limited thereto. 
     On the other hand, if the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the untrackable status, it represents that the sensing result and/or sensing data provided by the first tracking sensor may be not enough for the processor  204  to track the pose of the tracking device  200 . 
     Therefore, in step S 430 , in response to determining that the first sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the untrackable status, the processor  204  decreases the first sensing rate of the first tracking sensor. 
     In the first embodiment where the first sensing rate is assumed to be the corresponding frame rate of the first tracking sensor, the processor  204  can, for example, decrease the first sensing rate of the first tracking sensor to be any value less than a predetermined rate of the first sensing rate. For example, if the predetermined rate of the first sensing rate is 60 fps, the processor  204  can decrease the first sensing rate to be any value less than 60 fps, such as 1 fps, 30 fps, and so on. See  FIG.  5    for more examples. 
       FIG.  5    shows a schematic diagram of the sensing rate adjustment of several tracking sensors according to an embodiment of the disclosure. In  FIG.  5   , the processor  204  determines the sensing result of each of the tracking sensors  2061 - 2064  and accordingly determine whether each of the tracking sensors  2061 - 2064  corresponds to the untrackable status or the trackable status. 
     In  FIG.  5   , it is assumed that the sensing result of each of the tracking sensors  2061  and  2062  at a timing point T 1  indicates that the tracking sensors  2061  and  2062  correspond to the trackable status. In this case, the processor  204  can maintain the sensing rates of the tracking sensors  2061  and  2062  as the predetermined rate (e.g., T fps), and hence the tracking sensors  2061  and  2062  can capture one image (shown as the rectangles with dots) every 1/T second. 
     In addition, it is assumed that the sensing result of each of the tracking sensors  2063  and  2064  at the timing point T 1  indicates that the tracking sensors  2063  and  2064  correspond to the untrackable status. In this case, the processor  204  can decrease the sensing rates of the tracking sensors  2063  and  2064  to be, for example, a half of the predetermined rate (i.e., T/2 fps), and hence the tracking sensors  2063  and  2064  can capture one image every 2/T second, but the disclosure is not limited thereto. 
     The similar principle introduced in  FIG.  5    can be used for the second embodiment where the tracking sensors are implemented as beacon sensors, but the disclosure is not limited thereto. 
     In one embodiment, the processor  204  can obtain a second sensing result of the first tracking sensor after step S 430  and determine whether the second sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the trackable status. 
     In the embodiments of the disclosure, the processor  204  can obtain the second sensing result by using the approaches similar to obtaining the first sensing result, which would not be repeated herein. 
     In one embodiment, in response to determining that the second sensing result of the first tracking sensor indicates that the first tracking sensor corresponds to the trackable status, the processor  204  can determine that the first tracking sensor is changed from the untrackable status to the trackable status; otherwise the processor  204  can determine that the first tracking sensor is maintained as the untrackable status. 
     In one embodiment, in response to determining that the first tracking sensor is changed from the untrackable status to a trackable status, the processor  204  can increase or recover the first sensing rate of the first tracking sensor; otherwise the processor  204  can maintain the first sensing rate of the first tracking sensor. 
     For example, assuming that the processor  204  determines that the sensing result of the tracking sensor  2063  at a timing point T 5  indicates that the tracking sensor  2063  corresponds to the trackable status, the processor  204  can increase the sensing rate of the tracking sensor  2063  to be any value between T/2 and T or directly recover the sensing rate of the tracking sensor  2063  to be the predetermined rate (i.e., T fps), but the disclosure is not limited thereto. 
     In one embodiment, in response to determining that the first tracking sensor corresponds to the untrackable status, the processor  204  can record a current pose of the tracking device  200  as a specific pose. In one embodiment, after increasing or recovering the first sensing rate of the first tracking sensor, the processor  204  can determine whether the pose of the tracking device  200  is changed to correspond to the specific pose. In response to determining that the pose of the tracking device  200  is changed to correspond to the specific pose, it represents that the first tracking sensor would correspond to the untrackable status again, and hence the processor  204  can decrease the first sensing rate of the first tracking sensor based on the teachings in the above again, but the disclosure is not limited thereto. 
     In another embodiment, in response to determining that the first tracking sensor corresponds to the untrackable status, the processor  204  can record a current viewpoint (e.g., the viewpoint that faces the whit wall  301  of  FIG.  3   ) of the first tracking sensor of the tracking device  200  as a specific viewpoint. In one embodiment, after increasing or recovering the first sensing rate of the first tracking sensor, the processor  204  can determine whether a second tracking sensor of the tracking sensors  2061 - 206 N corresponds to the specific viewpoint. In response to determining that the second tracking sensor corresponds to the specific viewpoint, it represents that the second tracking sensor would also correspond to the untrackable status, and hence the processor  204  can decrease the second sensing rate of the second tracking sensor based on the ways similar to decreasing the first sensing rate of the first tracking sensor. 
     In one embodiment, after increasing or recovering the first sensing rate of the first tracking sensor, the processor  204  can determine whether the first tracking sensor corresponds to the specific viewpoint again. In response to determining that the first tracking sensor corresponds to the specific viewpoint again, it represents that the first tracking sensor correspond to the untrackable status again, and hence the processor  204  can decrease the first sensing rate of the first tracking sensor again, but the disclosure is not limited thereto. 
     In one embodiment, the processor  204  can decrease the first sensing rate of the first tracking sensor via disabling the first tracking sensor. In particular, the processor  204  can turn off the first tracking sensor, such that the first sensing rate of the first tracking sensor can be regarded as 0, but the disclosure is not limited thereto. 
     In one embodiment, when determining whether the first tracking sensor is changed from the untrackable status to the trackable status, the processor  204  can monitoring a movement of the tracking device  200  after determining that the first tracking sensor corresponds to the untrackable status. In one embodiment, the tracking device  200  can include a motion detection circuit (e.g., an inertial measurement unit (IMU)) coupled to the processor  204 , and the processor  204  can monitor the movement of the tracking device  200  based on the motion data sensed by the motion detection circuit. 
     In various embodiments, the movement of the tracking device  200  can be characterized by the moving speed and/or the moving distance of the tracking device  200 . In one embodiment, the processor  204  can determine whether the moving speed of the movement of the tracking device  200  exceeds a speed threshold or whether a moving distance of the movement of the tracking device exceeds a distance threshold. In the embodiments of the disclosure, the speed threshold can be determined as any value that is enough to regard the tracking device  200  as moving fast, and the distance threshold can be determined as any value that is enough to regard the tracking device  200  as moving far. 
     In one embodiment, in response to determining that the moving speed of the movement of the tracking device exceeds the speed threshold or the moving distance of the movement of the tracking device exceeds the distance threshold, it represents that the first tracking sensor is possible to provide enough sensing result and/or sensing data for pose tracking. Therefore, the processor  204  can determine that the first tracking sensor is changed from the untrackable status to the trackable status and accordingly increase or recover the first sensing rate of the first tracking sensor. 
     In one embodiment, whenever the motion detection circuit detects that the tracking device  200  is substantially moving (i.e., not stationary or just slightly moving/shaking), the motion detection circuit can provide an interruption signal to the processor  204 . In one embodiment, the processor  204  can determine that each of the tracking sensors  2061 - 206 N is corresponding to the trackable status and accordingly adjusting the sensing rate of each of the tracking sensors  2061 - 206 N. 
     In one embodiment, for those sensors which are already corresponding to the trackable status, the processor  204  can maintain their sensing rates. For those sensors which are changed from corresponding to the untrackable status to corresponding to the trackable status, the processor  204  can increase or recover their sensing rates, but the disclosure is not limited thereto. See  FIG.  6    for more examples. 
       FIG.  6    shows a schematic diagram of the sensing rate adjustment of several tracking sensors according to an embodiment of the disclosure. In  FIG.  6   , it is assumed that: (1) the tracking sensor  2061  is disabled in a duration D 1  and recovers the sensing rate thereof at a timing point T 1  due to corresponding to the trackable status; (2) the tracking sensor  2062  is disabled in a duration D 2  and recovers the sensing rate thereof at a timing point T 2  due to corresponding to the trackable status; (3) the tracking sensors  2063  and  2064  are disabled in durations D 3  and D 4  due to corresponding to the untrackable status. 
     In the embodiment, assuming that the processor  204  receives an interruption signal S 1  (e.g., the tracking device  200  is determined to be moving fast and/or far enough) at the timing shown in  FIG.  6   , the processor  204  can determine that each of the tracking sensors  2061 - 2064  is corresponding to the trackable status and accordingly adjust the sensing rate of each of the tracking sensors  2061 - 2064 . For example, since the tracking sensors  2061  and  2062  are already corresponding to the trackable status, the processor  204  can maintain their sensing rates. Since the tracking sensors  2063  and  2064  are changed from corresponding to the untrackable status to corresponding to the trackable status, the processor  204  can increase or recover their sensing rates, but the disclosure is not limited thereto. 
     The disclosure further provides a computer readable storage medium for executing the method for managing tracking sensors. The computer readable storage medium is composed of a plurality of program instructions (for example, a setting program instruction and a deployment program instruction) embodied therein. These program instructions can be loaded into the tracking device  200  and executed by the same to execute the method for managing tracking sensors and the functions of the tracking device  200  described above. 
     In summary, the embodiments of the disclosure can decrease the sensing rate of a tracking sensor when determining that the sensing result and/or sensing data thereof may not be enough for tracking the pose of the tracking device. Accordingly, the power consumption of the tracking sensor can be reduced while reducing the computation loading of the processor. Due to the reduction of power consumption, the tracking device will generate less heat, which reduces the need to install a cooling mechanism in the tracking device. In this way, the structure of the tracking device can be designed to be smaller and lighter, which makes the tracking device more suitable to be worn by the user. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.