Patent Publication Number: US-2010125413-A1

Title: External gyroscope and method of using the same to assist in navigation and positioning

Description:
FIELD OF THE INVENTION 
     The present invention relates to an external gyroscope connectable to a navigator of any type to assist in navigation and positioning, and more particularly, to a method of using an external gyroscope to assist in navigation and positioning. 
     BACKGROUND OF THE INVENTION 
     Nowadays, various satellite navigation systems have been widely used in different fields. For example. there are various in-car navigation systems and portable navigation devices. Also. many consumptive high-tech products, such as notebook computers, cellular phones, personal digital assistants (PDAs), etc., all can have navigation software installed thereon and be connected to a GPS receiver to provide navigation function. In this manner, the high-tech products can have increased added value. 
     Most of the existing navigators would sometimes display incorrect instructions due to certain factors, such as low accuracy or poor quality of satellite positioning signal. For example, when a car enters a tunnel, the navigator mounted on the car is not able to receive the satellite positioning signal and becomes useless. To overcome this problem, an advanced navigator would usually be equipped with a gyroscope to assist the navigator in continuously providing navigation and positioning function. 
     The gyroscope detects the movement of an object, such as braking, accelerating, or turning of a car, to thereby obtain some relevant data, such as instantaneous relative acceleration and instantaneous relative angular displacement due to inertia. Through calculation conducted on these data, it would help the navigator in correctly determining the moving speed and moving direction of the car. Taiwanese Patent Number I268201 entitled “Three-axis Mini-gyroscope” and Taiwanese Patent Number I284193 entitled “Car Navigator with Display Correcting Ability and Display Correcting Method Thereof” all disclose techniques related to navigation. 
     The currently available gyroscopes are small in size and adopt technique on chip. However, while there are many different types of navigators and navigation software, all the gyroscope-equipped navigators must be connected to the gyroscope in terms of hardware and software design thereof. Therefore, the gyroscope is usually provided only in the highly expensive advanced navigators. That is, most of the currently commercially available navigators do not support the gyroscopes and therefore are not advantageously assisted by the gyroscopes to provide improved navigation and positioning function. 
     It is therefore tried by the inventor to develop an external gyroscope, which can be plugged in any type of navigator without the problem of compatibility, just like a flash disk using a USB interface, so that all the existing navigators can use an external gyroscope to help in navigation and positioning. And, for this purpose, the navigator can have a driver installed thereon to enable compatibility of the external gyroscope with all types of navigators, so that the navigators can use an external gyroscope to help in the navigation and positioning without the need of modifying the navigation software thereof. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide an external gyroscope connectable to a navigator of any type to assist the navigator in navigation and positioning, so that when a car equipped with the navigator enters a tunnel or the quality of GPS signal received by the navigator is poor, the external gyroscope connected to the navigator can help the navigator in providing accurate navigation and positioning. 
     Another object of the present invention is to provide a method of using an external gyroscope to assist in navigation and positioning. The method is applicable to a navigator that uses a GPS signal to determine a user&#39;s position. moving direction, and moving speed. 
     To achieve the above and other objects, the method of using an external gyroscope to assist in navigation and positioning according to an embodiment of the present invention includes the steps of: connecting an external gyroscope to a navigator. so that the navigator can acquire angular displacement and acceleration data generated by the external gyroscope; acquiring a GPS signal and calculating based on the GPS signal to obtain current moving direction and moving speed; combining the angular displacement and acceleration data with the current moving direction and moving speed, and conducting calculation on the combined data to generate a positioning signal for a next position; and replacing the GPS signal with the positioning signal for the next position and transmitting the positioning signal to the navigator. 
     There is also a method of using an external gyroscope to assist in navigation and positioning according to another embodiment of the present invention including the following steps: connecting an external gyroscope to a navigator; the navigator acquiring a GPS signal and calculating current moving direction and moving speed based on the GPS signal; and the navigator acquiring angular displacement and acceleration data generated by the external gyroscope, combining the angular displacement and acceleration data with the current moving direction and moving speed, and conducting calculation on the combined data to generate a positioning signal for the next position. 
     To achieve the above and other objects of the present invention, an external gyroscope connectable to a navigator according to the present invention includes a mini-gyroscope adapted to generate angular displacement and acceleration data, a second connector for correspondingly connecting to a first connector on the navigator; and a control unit electrically connected to and between the mini-gyroscope and the second connector. The control unit acquires the angular displacement and acceleration data and transmits the same to the navigator. Or, alternatively, the control unit can calculate based on the angular displacement and acceleration data to generate a positioning signal for a next position, and then transmits the positioning signal to the navigator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
         FIG. 1  schematically shows a system architecture based on which the present invention is implemented: 
         FIG. 2  is a hardware block diagram of an external gyroscope according to the present invention; 
         FIG. 3  is a flowchart showing the steps included in a method of using an external gyroscope to assist in navigation and positioning according to a first embodiment of the present invention; and 
         FIG. 4  is a flowchart showing the steps included in a method of using an external gyroscope to assist in navigation and positioning according to a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIG. 1  that schematically shows a system architecture based on which the present invention is implemented. The present invention provides an external gyroscope  10 , which can be connected to and used with a currently available navigator  20  of any type. The navigator  20  is internally installed a type of navigation software for receiving a global positioning system (GPS) signal to enable correct navigation. The navigator  20  also includes a monitor, a control operator, and a voice speaker. 
     The currently commercially available navigators can be generally divided into two types. namely, navigators with a built-in GPS receiving chip and navigators requiring an external GPS receiver. For example, most existing car navigators and portable navigators have a built-in GPS receiving chip. On the other hand, notebook computers, hand computers, smart phones, and personal digital assistants (PDAs) that have internally installed navigation software would require an external GPS receiver to enable the navigation function thereof. 
     The following description of the external gyroscope of the present invention is based on a navigator  20  using an external GPS receiver  30 .  FIG. 2  is a hardware block diagram of the external gyroscope  10  according to the present invention. Please refer to  FIGS. 1 and 2  at the same time. The navigator  20  is generally provided with one or more external connector ports, such as a memory card connector port, a GPS receiver connector port, an AV input port, a Bluetooth interface, etc. Herein, the navigator  20  is provided with at least one first connector  21  for connecting to the external gyroscope  10 . The external gyroscope  10  is correspondingly provided with a second connector  11  for connecting to the first connector  21  on the navigator  20 . 
     The external gyroscope  10  further includes a mini-gyroscope  12  and a control unit  13 . The mini-gyroscope  12  is able to generate instantaneous angular displacement and acceleration data in the instant a vehicle moves. The mini-gyroscope  12  can be provided with a G-sensor or a pressure altimeter to help in correcting any height error in the GPS signal. The control unit  13  is mainly a controller of the transmission interface at the second connector  11 . The control unit  13  is electrically connected to the mini-gyroscope  12  and the second connector  11  to acquire the angular displacement and acceleration data generated by the mini-gyroscope  12  and transmit the acquired data to the navigator  20  via the second connector  11 . 
     A data converter  14  can be provided between the control unit  13  and the mini-gyroscope  12 . The data converter  14  converts the angular displacement and acceleration data generated by the mini-gyroscope  12  into transmission data corresponding to the connection interface of the second connector  11 . Preferably, the control unit  13  is able to directly convert the data, so that the data converter  14  can be omitted. 
     The external gyroscope  10  is further provided with at least one third connector  15  electrically connected to the control unit  13  for connecting to an external GPS receiver  30 . Therefore, the navigator  20  without a built-in GPS receiving chip can have its external GPS receiver  30  connected to the third connector  15  on the external gyroscope  10 . 
     The control unit  13  of the external gyroscope  10  is able to automatically detect that a GPS receiver  30  has been connected to the third connector  15 , and acquires the GPS signal generated by the GPS receiver  30 . The control unit  13  will then combine the angular displacement and acceleration data generated by the mini-gyroscope  12  with the GPS signal, and conduct calculation on the combined data to derive a positioning signal for a next position. The positioning signal is then transmitted to the navigator  20  for navigation and positioning. 
     According to the illustrated embodiment of  FIG. 2 , modification or change of the navigation software installed on the navigator  20  call be minimized. This is because the external gyroscope  10  will automatically combine the angular displacement and acceleration data with the GPS signal to derive the positioning signal for a next position. This helps in correcting the GPS signal generated by the GPS receiver  30  before the GPS signal is transmitted to the navigator  20 . Therefore, the GPS signal acquired by the navigator  20  is always an accurate positioning signal, and it is not necessary for the navigation software in the navigator  20  to calculate the next position. 
     The first connector  21  on the navigator  20 , the second connector  11  and/or the third connector  15  on the external gyroscope  10 , and the GPS receiver  30  are of the same connection interface, which can be a universal serial bus (USB) interface, an RS-232 interface, a PS/2 interface, an IEEE 1394 interface. or any universal asynchronous receiver/transmitter (UART) interface. For example, the first connector  21  can be a USB female connector, while the second connector  11  can be a mating USB male connector. Alternatively, the first and the second connector  21 .  11  can be two PS/2 female connectors connectable to each other via a PS/2 connection cable. 
     The first connector  21  and the second connector  11  or the third connector  15  and the GPS receiver  30  can be otherwise a memory card connection interface or a Personal Computer Memory Card Association (PCMCIA) interface. such as an SD card connector, a CF card connector, a PCMCIA connector, etc. Alternatively, the first connector  21  and the second connector  11  or the third  10  connector  15  and the GPS receiver  30  can be otherwise a Bluetooth interface for wireless connection via Bluetooth technique. 
     The external gyroscope  10  of the present invention can further include a car speed line connector  16  for connecting to a car speed line  22  to acquire car speed data, which can substitute for the acceleration data generated by the external gyroscope  10 . Therefore, the burden on the control unit  13  for calculating the car moving speed during the derivation of the positioning signal can be lowered. 
     Please now refer to  FIG. 3 , which is a flowchart showing the steps included in a method of using an external gyroscope to assist in navigation and positioning according to a first embodiment of the present invention. As having been described above, the external gyroscope  10  is connected to a navigator  20 , which is able to receive a GPS signal and determines the user&#39;s position, moving direction, and moving speed based on the GPS signals. The method of using the external gyroscope  10  to assist a navigator  20  in navigation and positioning according to the first embodiment of the present invention includes the following steps: 
     Step S 100 : Connect the external gyroscope  10  to the navigator  20 , so that the navigator  20  can acquire the angular displacement and acceleration data generated by the external gyroscope  10 . The external gyroscope  10  can be further provided with a G-sensor or a pressure altimeter to help in correcting any height error in the GPS signal. 
     Step S 105 : Connect the GPS receiver  30  to the external gyroscope  10 , and turn on the navigator  20  to run the built-in navigation software thereof. 
     Step S 110 : When the navigation software runs and needs to acquire a GPS signal from the GPS receiver  30 . the external gyroscope  10  acquires and combines the GPS signal generated by the GPS receiver  30  with the angular displacement and acceleration data generated by the mini-gyroscope  12 , and conducts necessary calculation based on the combined GPS signal and angular displacement and acceleration data. 
     Step S 115 : The control unit  13  determines whether the GPS signal is in good signal receiving quality. 
     Step S 120 : If yes, the received GPS signal is used as the positioning signal for a next position. 
     Step S 125 : Or, if no, the angular displacement data generated by the external gyroscope  10  is used to calculate the current moving direction and angular position. Meanwhile, the acceleration data generated by the external gyroscope  10  is used to calculate the vehicle moving speed, so as to determine the positioning signal for a next position. 
     Step S 130 : Finally, the positioning signal for the next position is transmitted to the navigator  20  for the same to provide required navigation and positioning. 
     Alternatively, the external gyroscope  10  can be connected to a car speed line  22  to acquire data about the vehicle moving speed. In this case, the car moving speed data can substitute for the acceleration data generated by the mini-gyroscope  12 , and be combined with the GPS signal for calculating the positioning signal for the next position.  FIG. 4  is a flowchart showing the steps included in a method of using an external gyroscope to assist in navigation and positioning according to a second embodiment of the present invention. In the second embodiment, the external gyroscope  10  is connected to a navigator  20  having a built-in GPS receiving chip. The built-in GPS receiving chip is controlled by navigation software installed in the navigator. The method of using an external gyroscope to assist in navigation and positioning according to the second embodiment of the present invention includes the following steps: 
     Step S 200 : Install a resident driver in the navigator  20  for detecting any acquisition of a GPS signal by the navigator. The resident driver enables less modification or change to the navigation software and accordingly, increased system compatibility of the external gyroscope  10  with the navigator  20 . 
     Step S 205 : Connect the external gyroscope  10  to the navigator  20  for the latter to acquire angular displacement and acceleration data generated by the mini-gyroscope  12  of the external gyroscope  10 . 
     Step S 210 : The navigator  20  acquires a GPS signal and conducts calculation based on the GPS signal to obtain current moving direction and moving speed. 
     Step S 215 : The resident driver installed on the navigator  20  acquires the angular displacement and acceleration data generated by the external gyroscope  10 . The external gyroscope  10  can be further provided with a G-sensor or a pressure altimeter to help in correcting any height error in the GPS signal. Then, the resident driver combines the current moving direction and moving speed with the angular displacement and acceleration data for calculating a positioning signal for a next position. 
     Step S 220 : The resident driver determines whether the GPS signal is in good signal receiving quality. 
     Step S 225 : If yes, the GPS signal is combined with the angular displacement and acceleration data and the moving direction and moving speed to calculate and generate the positioning signal for the next position. 
     Step S 230 : Or, if no, the angular displacement and acceleration data generated by the external gyroscope  10  is directly used to calculate and generate the positioning signal for the next position. 
     In the second embodiment, the navigator  20  can be connected to a car to speed line  22  to acquire car speed data. In this case, the car speed data can substitute for the acceleration data provided by the external gyroscope  10  to be combined with the GPS signal for calculating the positioning signal for the next position. 
     A biggest difference between the method in the first embodiment and the method in the second embodiment mainly is that, in the first embodiment, the positioning signal for the next position is calculated and then transmitted to the navigator by the external gyroscope, while in the second embodiment, the external gyroscope simply transmits data to the navigator for the navigator to calculate the positioning signal. Thus, the external gyroscope used in the method of the first embodiment enables the navigator to have higher compatibility, while the external gyroscope used in the method of the second embodiment has cost-effective design and provides best operating efficiency. 
     The present invention has been described with some preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.