Abstract:
A track measurement apparatus for sports shoes includes a first accelerometer module located at a rear side of a sole of a shoe and a second accelerometer module located at a front side of the sole of the shoe to measure acceleration alterations of the shoe worn by a user in striding forwards during running, and also derive alterations of angular velocity and angle while the shoe is stridden forwards to get motion status of the shoe.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a dynamic measurement system of footwear and particularly to a track measurement apparatus for sports shoes. 
       BACKGROUND OF THE INVENTION 
       [0002]    Gait analysis aims to get motion tracks of people during running or walking through a dynamic graphic technique. In sports medicine, gait analysis can be used to get insight of coordination problems among skeletons, joints and muscles, thereby to get early treatments needed. 
         [0003]    For instance, U.S. Pat. No. 6,301,964 discloses a motion analysis system installed on a rear heel of a shoe. It comprises a horizontal accelerometer, a vertical accelerometer and a tilt sensor. Through the horizontal accelerometer and vertical accelerometer, alterations of acceleration in two directions can be obtained. And through the tilt sensor, a tilt direction can also be obtained. The measured data is input into a processor for integration to derive speed and displacement, namely the position of the shoe can be gotten; then the result is sent to a database through a transmission element for saving, thus the positions of the shoe at different times are gathered to get motion tracks of the shoe, i.e. gait analysis of the shoe can be accomplished. 
         [0004]    Although the aforesaid conventional technique can get the result of gait analysis, the horizontal accelerometer, vertical accelerometer and tilt sensor are all located outside the shoe, they are prone to be hit and damaged, and positioning function could suffer. It also requires complex calculation to integrate acceleration alterations of the horizontal accelerometer and vertical accelerometer, and get the tilt direction of the tilt sensor to obtain the shoe&#39;s position. It also does not have a datum point, hence could generate erroneous measurement on non-lifting foot movements, such as downhill movement. It still leaves a lot to be desired and cannot fully meet requirements. 
       SUMMARY OF THE INVENTION 
       [0005]    The primary object of the present invention is to provide a track measurement apparatus for sports shoes to simply and quickly get motion status of a shoe. 
         [0006]    To achieve the foregoing object, the invention provides a track measurement apparatus for sports shoes located on a sole of a shoe. It includes a measuring device comprising a first accelerometer module, a second accelerometer module, a first signal processing unit and an interrelation processing unit. The first accelerometer module is located at a rear side of the sole of the shoe, and the second accelerometer module is located at a front side of the sole of the shoe. The first and second accelerometer modules detect alterations of accelerations when the shoe is stridden forwards. The first accelerometer module and the second accelerometer module are spaced at a distance which is defined as a rotation radius. 
         [0007]    The first signal processing unit and interrelation processing unit are located on the shoe. The interrelation processing unit receives feedback from the first signal processing unit. The first signal processing unit and interrelation processing unit are linked to the first accelerometer module and second accelerometer module to receive the acceleration alterations, and based on the rotation radius, alterations of speed, angular velocity and time are derived by integration while the shoe is stridden, and then another alterations of speed and time are derived by integration to obtain the angle, speed and angular velocity of the shoe leaving the ground, thereby get the motion status of the shoe. 
         [0008]    In short, the invention provides many advantages, notably: through a simple integration process module, the speed and angular velocity of the shoe leaving the ground can be derived through integration due to the simple process. Moreover, the first accelerometer module, second accelerometer module, first signal processing unit and interrelation processing unit are embedded in the shoe and less likely to be damaged, thus can meet actual requirements. 
         [0009]    The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to an embodiment and the accompanying drawings. The embodiment serves merely for illustrative purpose and is not the limitation of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a system block diagram of the invention. 
           [0011]      FIG. 2  is a schematic view of an embodiment of an accelerometer module of the invention. 
           [0012]      FIG. 3A  is a schematic view according to the invention in a measurement condition. 
           [0013]      FIG. 3B  is a fragmentary enlarged view according to  FIG. 3A . 
           [0014]      FIG. 4  is a system block diagram of the invention adopted on a shoe equipped with a control module. 
           [0015]      FIG. 5  is a schematic view of an embodiment of the invention in a use condition. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0016]    Referring to  FIGS. 1 ,  2 ,  3 A and  3 B, the invention includes a measuring device  30  which is linked wirelessly through a first signal wireless transceiver  35  to a host device  40  equipped with a second signal wireless transceiver  41 . The measuring device  30  comprises a first accelerometer module  31 , a second accelerometer module  32 , a first signal processing unit  33  linked to the first signal wireless transceiver  35  and an interrelation processing unit  34 . The first accelerometer module  31  is located at a rear side of the sole of a shoe  10 , and the second accelerometer module  32  is located at a front side of the sole of the shoe  10 . The first accelerometer module  31  and second accelerometer module  32  aim to measure acceleration alterations of the shoe  10  during striding forwards. The first accelerometer module  31  and second accelerometer module  32  are spaced at a distance which is defined as a rotation radius R. 
         [0017]    The first signal processing unit  33  and interrelation processing unit  34  also are located on the shoe  10 . The interrelation processing unit  34  receives feedback from the first signal processing unit  33 . The first signal processing unit  33  and interrelation processing unit  34  are connected to the first accelerometer module  31  and second accelerometer module  32  to receive acceleration alterations a t . Based on the rotation radius R and equation a t =αR, alterations of an angular acceleration α can be derived; then through another equation V=ωR and an integration process, alterations of speed V, angular velocity w and time can be obtained when the shoe  10  is stridden forwards; through another integration process, alterations of the angle θ and time also can be gotten, and the angle θ, speed V and angular velocity ω of the shoe  10  leaving the ground can be obtained. Thereby the motion status of the shoe can be known. 
         [0018]    Referring to  FIG. 4 , the measuring device  30  of the invention can be used to measure an exercise mode of the shoe  10 . It can be incorporated with the host device  40  and a control device  50  when in use. The measuring device  30  further includes the first signal wireless transceiver  35 . The host device  40  includes the second signal wireless transceiver  41 , a second signal processing unit  42 , an input/output interface  43 , a data access unit  45  and a multimedia output medium  46 . The control device  50  includes a third signal wireless transceiver  51 , a third signal processing unit  52 , a driving control unit  53  and a controlled system module  54 . 
         [0019]    The measuring device  30 , host device  40  and control device  50  are interconnected wirelessly through the first, second and third signal wireless transceivers  35 ,  41  and  51 . The host device  40  is linked to the second signal wireless transceiver  41  through the second signal processing unit  42  to control the measuring device  30  and control device  50 , linked to the input/output interface  43  to input/output a control parameter, connected to the data access unit  45  to access data, and linked to the multimedia output medium  46  to output multimedia information. 
         [0020]    The control device  50  is linked to the third signal wireless transceiver  51  and driving control unit  53  through the third signal processing unit  52  to receive control signals from the host device  40 , and is linked to and controls the controlled system module  54  through the driving control unit  53 . In an embodiment, the controlled system module  54  can be a controlled system module (such as a motor module) of a treadmill. After the measuring device  30  obtains the motion status of the shoe, the driving control unit  53  is linked to and controls motion of the controlled system module  54  according to the motion status of the shoe, and the operation of the treadmill can be adjusted in response to actual gaits to meet actual requirements. 
         [0021]    Referring to  FIGS. 4 and 5 , the host device  40  can be installed on a wristwatch  70 , and the control device  50  is installed on a treadmill  80 . When a user  60  wears the wristwatch  70  and runs on the treadmill  80 , he/she can do a personalized setting through the input/output interface  43 . After the measuring device  30  obtains the motion tracks of the shoe  10 , through operation and control of the control device  50 , the rotational speed of the treadmill  80  is automatically corresponding to the gaits of the user  60  to achieve safety without falling behind the speed of the treadmill  80  and prevent risks. Moreover, after the user  60  has worn the wristwatch  70 , he/she can get signals measured by the measuring device  30  through the host device  40  located on the wristwatch  70 , namely the user  60  can get the motion tracks through the wristwatch  70  to know the current motion status. 
         [0022]    As a conclusion, through the first accelerometer module  31 , second accelerometer module  32 , first signal processing unit  33  and interrelation processing unit  34 , and also the measured accelerations and the distance between the first accelerometer module  31  and second accelerometer module  32 , the present invention can derive the speed and angular velocity of the shoe  10  leaving the ground through an integration process. The process is simpler. Moreover, the first accelerometer module  31 , second accelerometer module  32 , first signal processing unit  33  and interrelation processing unit  34  can be embedded in the shoe  10  without being damaged easily, thus can meet actual requirements.