Patent Publication Number: US-2021180952-A1

Title: Microelectromechanical gyroscope system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a microelectromechanical gyroscope system, and more particularly to a microelectromechanical gyroscope system having multiple sensing module boards. 
     2. Description of Related Art 
     With the rapid development of semiconductor technology, the sensors based on micro-electromechanical systems (MEMS) have been widely used in commercial and military applications. These sensors are characterized by their small size, low cost, and low power consumption. In the navigation and control of a flying vehicle, a gyroscope is an important sensing element for measuring azimuth or angle. However, the sensing precision of the MEMS gyroscope is low, which limits its applicability in high-precision navigation and control. 
     In order to solve the above-mentioned problem of low precision of a single MEMS gyroscope, please refer to  FIG. 1 . The conventional technology is to solder multiple MEMS gyroscopes  601  through the Surface Mount Technology (SMT) or the through-hole technology) on a printed circuit board  602 . The multiple micro-electromechanical gyroscopes  601  forms a gyroscope array  603 , and the printed circuit board  602  has a signal processor  604  for collecting sensor signals of the above gyroscopes. Then, through a cross calibration of the MEMS gyroscopes  601  and performing a signal filtering and synthesis by the signal processor  604 , the noise can be greatly reduced so as to improve the sensing precision of the MEMS gyroscope system. 
     However, there are still some problems with the above-mentioned conventional techniques. Due to the structure of the gyroscope, each gyroscope has three measurement axes (respectively, a x axis, a y axis, and a z axis), and the three measurement axes are perpendicular to each other. For improving the measurement precision of the gyroscope, the three measurement axes of each gyroscope should be aligned with the system coordinate axes, that is, Rx, Ry, and Rz shown in  FIG. 1 . Accordingly, the signals and data measured by the measurement axes can precisely represent the motion state of the system. Wherein, the system coordinate axes Rx, Ry, Rz are perpendicular to each other to form a rectangular coordinate system. However, due to the circuit board manufacturing process, when the gyroscope  601  is soldered, the gyroscope  601  is placed flat on the printed circuit board  601 , so that only the z axis of the measurement axis of the gyroscope is aligned with the system coordinate axis Rz, and the other measurement coordinate axes (x axis and y axis) may have deviation with respect to the system coordinate axes (Rx, Ry) as shown in  FIG. 1 . That is, in the three measurement axes of the gyroscope, only one of the measurement axes is aligned with the system coordinate axis, and the other axes may have deviation. As shown in  FIG. 1 , the x axis of the measurement axes of the gyroscope has a deviation with respect to the Rx axis of the system coordinate axis, and the y axis of the measurement axes of the gyroscope has a deviation with respect to the Ry axis of the system coordinate axis. Therefore, the signals and data measured by the x axis and y axis of the measurement axes cannot precisely represent the motion status of the system. Therefore, no matter the signal processor filter and compensate the signal, the measurement precision of the system cannot be improved further. 
     Therefore, how to solve the problem of low sensing precision of the conventional microelectromechanical gyroscope system in order to expand the application field of the microelectromechanical gyroscope system is a problem required to be solved. 
     SUMMARY OF THE INVENTION 
     In order to solve the low sensing precision problem of the conventional microelectromechanical gyroscope system, the present invention provides a microelectromechanical gyroscope system, comprising: a first substrate, and the first substrate includes a first combination surface; a second substrate, and the second substrate includes a second combination surface; a third substrate, and the third substrate includes a first combination surface; a first sensing module board fixed to the first combination surface of the first substrate, and the first sensing module board includes multiple microelectromechanical gyroscopes and a first signal connection port; a second sensing module board fixed to the second combination surface of the second substrate, and the second sensing module board includes multiple microelectromechanical gyroscopes and a second signal connection port; a third sensing module board fixed to the third combination surface of the third substrate, and the third sensing module board includes multiple microelectromechanical gyroscopes and a third signal connection port; and a signal processing and control board electrically connected to the first sensing module board, the second sensing module board and the third sensing module board; wherein first substrate, the second substrate and the third substrate are perpendicular with each other; the first combination surface, the second combination surface and the third combination surface are also perpendicular with each other. 
     Wherein the first substrate, the second substrate, the third substrate form a coordinate system, and the coordinate system includes three system coordinate axes which are perpendicular with each other, as a X axis, a Y axis and a Z axis; each microelectromechanical gyroscope includes three measurement axes which are perpendicular with each other, as a x axis, a y axis and a z axis; wherein the z axis of the measurement axes of the microelectromechanical gyroscope on the first sensing module board can align with the Z axis of the system coordinate axes, the z axis of the measurement axes of the microelectromechanical gyroscope on the second sensing module board can align with the Y axis of the system coordinate axes, and the z axis of the measurement axes of the microelectromechanical gyroscope on the third sensing module board can align with the X axis of the system coordinate axes. 
     Wherein the signal processing and control board includes a first system connection port, a second system connection port, a third system connection port and a signal processor; the first system connection port electrically connects with the first signal connection port, the second system connection port electrically connects with the second signal connection port, and the third system connection port electrically connects with the third signal connection port. 
     Wherein the system connection ports and the signal connection ports are electrically connected through a cable way. 
     Wherein the system connection ports and the signal connection ports are electrically connected through a wireless way. 
     With the above structure, on each system coordinate axis of the microelectromechanical gyroscope system, at least one gyroscope is aligned with it for data acquisition and measurement. Accordingly, the measurement accuracy of the system is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of the microelectromechanical gyroscope system of the conventional art; 
         FIG. 2  is an exploded diagram of a microelectromechanical gyroscope system according to the present invention; 
         FIG. 3  is a schematic diagram of the microelectromechanical gyroscope system according to the present invention; and 
         FIG. 4  is a schematic diagram of a connection between the signal processing and control board and sensing module board according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to  FIG. 2  and  FIG. 3 .  FIG. 2  is an exploded diagram of the microelectromechanical gyroscope system of the present invention.  FIG. 3  is a schematic diagram of the microelectromechanical gyroscope system of the present invention. The microelectromechanical gyroscope system of the present invention includes a first substrate  100 , a second substrate  200 , a third substrate  300 , a first sensing module board  110 , the second sensing module board  210 , and the third sensing module board  310  and a signal processing and control board  400  (shown in  FIG. 4 ). Wherein, the first substrate  100 , the second substrate  200 , the third substrate  300  are perpendicular with each other in order to form a coordinate system. The coordinate system includes three coordinate axes which are perpendicular with each other, as the X axis, the Y axis and the Z axis shown in  FIG. 2 . The first substrate  100  includes a first combination surface  101 , the second substrate  200  includes a second combination surface  201 , and the third substrate  300  includes a third combination surface  301 . The first combination surface  101 , the second combination surface  201  and the third combination surface  301  are also perpendicular with each other. The first sensing module board  110  includes a first assembly surface  111  and a first signal connection port  112 . The second sensing module board  210  includes a second assembly surface  211  and a second signal connection port  212 . The third sensing module board  310  includes a third assembly surface  311  and a third signal connection port  312 . 
     Firstly, respectively disposing the multiple gyroscopes  500  on the first assembly surface  111  of the first sensing module board  110 , the second assembly surface  211  of the second sensing module board  210  and the third assembly surface  311  of the third sensing module board  311 . In other words, each of the sensing module boards  110 ,  210 ,  310  includes multiple gyroscopes  500 . Then, using the conventional surface-mount technology or the through-hole technology to solder the multiple gyroscopes  500  on the first assembly surface  111  of the first sensing module board  110 , the second assembly surface  211  of the second sensing module board  210  and the third assembly surface  311  of the third sensing module board  311 . Accordingly, as description above, because of the assembly process of PCB and the function of the gravity, for sensing module boards  110 ,  210 ,  310 , a z axis of measurement axis of the gyroscope  500  can align with module coordinate axes Rz 1 ′, Rz 2 ′ and Rz 3 ′ of sensing module board better. As shown in  FIG. 2 , when manufacturing the first sensing module board  110 , disposing the first sensing module board  110  to be flat, then, disposing the multiple gyroscopes  500  on the first assembly surface  111  of the first sensing module board  110 . Accordingly, because of the feature of the PCB (Printed Circuit Board) process and the function of the gravity, the z axis of measurement axis of the gyroscope  500  on the first sensing module board  110  can align with the module coordinate axis Rz 1 ′ of the first sensing module board  110  better. Similarly, the z axis of measurement axis of the gyroscope  500  on the second sensing module board  210  can align with the module coordinate axis Rz 2 ′ of the second sensing module board  210  better, and the z axis of measurement axis of the gyroscope  500  on the third sensing module board  310  can align with the module coordinate axis Rz 3 ′ of the third sensing module board  310  better. 
     Then, fixing the first sensing module board  110  to the first combination surface  101  of the first substrate  100 , fixing the second sensing module board  210  to the second combination surface  201  of the second substrate  200  and fixing the third sensing module board  310  to the third combination surface  301  of the third substrate  300 . Accordingly, the measurement precision of the system is greatly increased. The operation principle is described as following. When fixing the first sensing module board  110  to the first combination surface  101  of the first substrate  100 , the module coordinate axis Rz 1 ′ can align with the Z axis of the system coordinate axes. Because the z axis of the measurement axes of the gyroscope  500  is precisely aligned with the module coordinate axis Rz 1 ′ of the first sensing module board  110 , the z axis of measurement axes of the gyroscope  500  can align with the Z axis of the system coordinate axes precisely. Accordingly, using a signal measured by the gyroscope  500  on the first sensing module board  110  to represent a motion status of the microelectromechanical gyroscope system on the Z axis has a better precision degree. 
     Similarly, when fixing the second sensing module board  210  to the second combination surface  201  of the second substrate  200 , the module coordinate axis Rz 2 ′ can align with the Y axis of the system coordinate axes. Because the z axis of the measurement axes of the gyroscope  500  is precisely aligned with the module coordinate axis Rz 2 ′ of the second sensing module board  210 , the z axis of measurement axes of the gyroscope  500  can align with the Y axis of the system coordinate axes precisely. Accordingly, using a signal measured by the gyroscope  500  on the second sensing module board  210  to represent a motion status of the microelectromechanical gyroscope system on the Y axis has a better precision degree. Similarly, when fixing the third sensing module board  310  to the third combination surface  301  of the third substrate  300 , the module coordinate axis Rz 3 ′ can align with the X axis of the system coordinate axes. Because the z axis of the measurement axes of the gyroscope  500  is precisely aligned with the module coordinate axis Rz 3 ′ of the third sensing module board  310 , the z axis of measurement axes of the gyroscope  500  can align with the X axis of the system coordinate axes precisely. Accordingly, using a signal measured by the gyroscope  500  on the third sensing module board  310  to represent a motion status of the microelectromechanical gyroscope system on the X axis has a better precision degree. 
     Through the above way, each of the X axis, the Y axis and the Z axis of the microelectromechanical gyroscope system has a corresponding gyroscope  500  aligned with the axis to perform a measurement so that the measurement precision is higher than the conventional system. 
     With reference to  FIG. 4 , the signal processing and control board  400  includes a first system connection port  401 , a second system connection port  402 , a third system connection port  403  and a signal processor  410 . The first system connection port  401  electrically connects with the first signal connection port  112 . The second system connection port  402  electrically connects with the second signal connection port  212 . The third system connection port  403  electrically connects with the third signal connection port  312 . Through the above way, the high precision signals measured by the gyroscope  500  on each of the sensing module boards  110 ,  210 ,  310  can be transmitted to the signal processor  410  on the signal processing and control board  400 . After collecting, filtering and synthesizing the above measured signals, the motion status in the space of the microelectromechanical gyroscope system can be obtained in order to obtain the physical quantity such as azimuth or angle. The electric connection way can be a cable way or a wireless way. The cable way can use a connector, or directly welding to connect the system connection port and the signal connection port. The wireless method can be a wireless protocol such as Wi-Fi or Bluetooth, and the present invention is not limited. 
     Besides, because the microelectromechanical gyroscope system of the present invention obtains the motion status of the microelectromechanical gyroscope system on the X axis, the Y axis and the Z axis using three sensing module boards and the signal processing and control board is disposed separately, when the measurement precision of the microelectromechanical gyroscope is improved because of improving in the manufacture process, replacing one of the three sensing module boards can improve the sensing precision of the coordinate axis corresponding to the sensing module board. Replacing entire printed circuit board including the multiple gyroscopes and the signal processor is not required so that the system upgrade is very flexible. 
     The above embodiments of the present invention are not used to limit the claims of this invention. Any use of the content in the specification or in the drawings of the present invention which produces equivalent structures or equivalent processes, or directly or indirectly used in other related technical fields is still covered by the claims in the present invention.