TW200404163A - Method and apparatus for improving positioning of mobile communication devices using inertial positioning - Google Patents

Abstract

Mobile communication devices or mobile station positioning methods may be improved by employing an inertial positioning system in the mobile station. The inertial positioning system is to be used in conjunction with a primary MS positioning method (such as UL-TOA, E-OTD, or A-GPS) to determine the location of the mobile station. The inertial positioning system, using the last known position as a point of reference, continually computes the latest position of the mobile station using measurements gathered from sensors. The inertial positioning system calculated location may periodically be used in lieu of invoking the primary positioning method. In doing so, this method aims to improve time taken to locate position of a mobile station, and provide location estimates in situations where the primary positioning method is unable to do so.

Description

200404163 Π) 发明. Description of the invention [Technical field to which the invention belongs] The present invention relates to a position or positioning system. In particular, the present invention relates to a position or positioning system in a mobile communication device using an infrastructure system and an inertial system. [Prior art] Mobile communication systems are commonly referred to as mobile base stations, and usually use either a GSM (Global System for Mobile Communications) cellular network or a CDMA (Code Division Multiple Access) cellular network. Each honeycomb network type has various mechanisms for locating these mobile base stations. The GSM Location Service (LCS) uses the following methods to locate the location of the mobile base station: the increase of the arrival time (E-OTD) and the uplink time (UL-TOA) 'and GPS support. CDMA networks use the following methods: time difference of arrival (TDOA), angle of arrival (AOA), and global positioning system support (A-G P S). Other cellular networks have similar methods for locating mobile base stations. All of the above methods are radio-based. Refer to Gs M 03.71 for details covering GSM location services. An example of E-OTD technology is shown in U.S. Patent Document No. 6,061,021. Generally, radio-based location methods typically require at least three radio frequency (RF) signals to be able to triangulate and determine the location of the mobile base station. As far as GPS-based positioning systems are concerned, it is known in cellular networks such as GS M or CDMA that signals from at least three base stations are needed to determine the location of mobile base stations using (2) (2) 200404163. Signals from at least three GPS satellites. However, it will happen that the number of signals required to prevent the location of the mobile base station cannot be obtained. In addition, when the A-GPS method is required to acquire a GPS satellite, it takes several seconds to several minutes to locate the mobile base station. This method does not work well when the required GPS line of sight (L 0 S) is indoors or in high-density urban areas. In areas where the base station's geometric configuration is poor, the U L-TOA, E-OTD, TDOA, and AOA methods also fail to work well. Therefore, positioning systems that use only radio-based location methods cannot provide uninterrupted location updates or mobile base station tracking. U.S. Patent Document No. 6,240,3 67 and U.S. Patent Document No. 6,3 2 7,5 3 3 propose examples of a navigation system including a GPS integrated with an inertial navigation system. These navigation systems are typically used in vehicles. This navigation system is also good for mobile base stations. However, it does not apply to mobile base stations where MS manufacturers use radio location systems that do not use GPS. In order to solve the shortcomings of the above-mentioned conventional techniques, the main object of the present invention is to improve the position estimation of MS, provide such an estimation in an efficient and timely manner, and be applicable to different positioning techniques. SUMMARY OF THE INVENTION The present invention provides a method and device for improving a mobile communication device using inertial positioning. Therefore, in one aspect, the present invention provides an improved method for locating a mobile communication device including a main positioning system and an inertial positioning system (3) (3) 200404163 'The method includes the following steps: Decide whether to bypass the main positioning System; right cannot pass the main positioning system, use the main positioning system to perform positioning; if the main positioning system is bypassed or if the main positioning system cannot return an acceptable position estimate, then use the inertial positioning system to perform positioning. Therefore, in another aspect, the present invention provides a mobile base station including a mobile base station controller and an inertial positioning subsystem; the mobile base station controller is used to control the operation of the mobile base station and to communicate with the cellular network Communication to operate the main positioning system; and an inertial positioning subsystem to augment the main positioning system. [Embodiment] Referring to FIG. 1 ', there is no block diagram of a mobile communication device or a mobile base station 12 according to the present invention. The present invention proposes to add an inertial positioning subsystem [6] to the mobile base station 12 to augment its own main positioning system that relies on the cellular network as a radio base for triangulation measurement. Contains the hardware and software required for general operations and base stations 12 and mobile base station controllers 14 for communicating with the cellular network to operate the main positioning system for engaging the inertial positioning subsystem 16. The inertial positioning subsystem 16 uses the inertial positioning method to determine the position of the entire seat system 10. The preferred embodiment of the present invention is that the inertial positioning subsystem 16 is completely enclosed in the rack and attached to the rack of the mobile base station 12. Another embodiment has an inertia positioning subsystem 16 fixed to the MS 12 frame from the outside via a connection mechanism.

(4) (4) 200404163 Referring to FIG. 2, the inertial positioning subsystem 16 includes a sensor array 19, nine signal filters 30 a-i, and a processor module 40. The sensor array 19 further includes nine sensors. Nine sensors include: X-axis accelerometer 20, y-axis accelerometer 21, and z-axis accelerometer 22; X-axis magnetometer 23, y-axis magnetometer 24, and z-axis magnetometer 25; X-axis inclinometer 26 and y-axis inclinometers 27; and temperature sensors 28. The X-axis accelerometer 20, y-axis accelerometer 21, and z-axis accelerometer 22 measure the acceleration along the X, y, and z axes of the mobile base station 12 as the acceleration readings. Similarly, the X-axis magnetometer 23, the y-axis magnetometer 24, and the z-axis magnetometer 25 measure the geomagnetic fields along the X, y, and z axes of the mobile base station 12 as magnetic field readings. The X-axis inclinometer 26 and the y-axis inclinometer 2 7 measure the tilt of the mobile base station 12 around the X and y axes of the mobile base station 12 as the inclinometer readings. The temperature sensor 2 8 measures the temperature of the system 16. Each of the nine signal filters 30a-i sets the signal conditions read from the sensor to prevent confusion and reduce noise. The preferred embodiment uses solid state or microelectromechanical systems (MEMS) based sensors because they are small in size. It is also possible to use an integrated sensor having a plurality of sensors including a combination of the following methods: an accelerometer, a magnetometer, an inclinometer, and a temperature sensor. The processor module 40 performs analog-to-digital conversion of signals from the sensor array 19 and performs calculations required to determine the current position of the mobile base station 12. In a preferred embodiment, a processor, such as a microcontroller, a microprocessor, and the like that execute software programs stored in the memory, may be used instead of the processor -8-(5) 200404163 module 40. The orientation of the mobile base station 12 is characterized by the geomagnetic field measured by the magnetometers 23, 24, and 25, and the system tilt measured by the inclinometers 26, 27. The magnetometer reading caused by the magnetic interference place of the moving base station 12 is applied positively. From these frames, the azimuth (orientation) and oblique angle of the mobile base station 12 can be derived. The azimuth angle of the mobile base station 12 facing north is obtained by the proper angle of the oblique angle applied at the current position of the system. Moving a mobile base station 12 from space to another point will produce accelerometers 20, 21, measured accelerations. The processor module 40 applies temperature compensation to the readings of the sensor array 19. The initial location data of the mobile base station 12's initial position data obtained by using its own primary positioning system using the primary positioning method must be used for the initial positioning subsystem 16. This initial position data is then supplied to the inertial position subsystem 16. FIG. 3, FIG. 4, and FIG. 5 show states and activities of the post-operation program 100 performed by the processor module 40. FIG. 6 is a flowchart illustrating a front-end operation procedure 200 performed by the cellular network to determine the position of the mobile base station 12. The background job program 100 and the foreground job program 2000 run independently of each other and can be regarded as concurrent execution. Referring to Fig. 3, uninitialized 102 is a state where the inertial positioning subsystem 16 is on. In this state, because its original position is not noticed, the method provides no position estimate. Initialization state 1 is the inertial positioning subsystem 1 6 has received sufficient initialization-specific data. In this state, the inertial positioning subsystem 16 notices its initial position and is able to provide a position estimate. The north guidance point 22 The inertial positioning platform of the inertial platform -9- (6) (6) 200404163 Figures 4 and 5 mention several common messages or events. They include: location data message 120, location request 122, and internal timer event 124. The position data message 120 contains the position of the mobile base station 12 as determined by the main positioning method. The position request 1 22 basically requests the position of the mobile base station 12 as determined by the inertial positioning subsystem 16. Both the location data message 120 and the location request message 122 are from the cellular network generated by the front-end operation program 200. Internal timer events 1 2 4 are generated in the processor module 40 by clock signals at regular intervals. Referring to FIG. 4, when the processor module 40 receives the position data message 120, the position data 1 2 0 including the position of the mobile base station 12 is then stored 1 60 as the initial position. Next, the displacement vector of mobile base station 12 is reset to 16 2 to zero. This displacement vector means the displacement of the initial positions of mobile base station 12 and mobile base station 12. Then, the background job program 100 becomes the initialization 104 state. If a position request message 1 22 is received, the background operation program 100 will generate a “尙 Not Ready” 1 6 4 message, indicating that the inertial positioning subsystem 16 is not ready to provide a position estimate and the background operation program 100 remains in the unavailable position. Initialize the 102 state. Referring to FIG. 5, when the background operation program is in the initial state 104 and the position data message 120 is received, the position data 120 including the position of the mobile base station 12 is stored 180 as the initial position. Next, the displacement vector of the mobile base station 12 is reset to 1 8 2 to zero. The background job program 100 is maintained at the initialization 104 state. -10- u '··; .- 4 (7) (7) 200404163 If a position request message 1 2 2 is received, the background operation program i 〇〇 will proceed to the initial position and displacement vector of the mobile base station. Calculate 1 8 4 position estimates. Then, the location data is sent to; | 8 6 mobile base station controller 14 and then controller 14 communicates with the cellular network to transfer the location data. The background job program 100 is maintained in the initial state 104. The internal g Shishiyi event 1 2 4 ′ appears on the right, and the background operation program 1 00 will proceed to read 1 8 8 data from the sensor array 19. The data read is then used to update the 190 displacement vector. Background operation procedure 〖〇 〇 Maintained in the initial state of 104. Referring to FIG. 6, the foreground operation program 2000 is executed in a cellular network. This front-end operation procedure 2 00 is executed when the base station 12 position needs to be moved. First, the foreground process 200 checks to determine whether the main positioning system can be bypassed. The criteria for such decisions are user-definable and may vary from case to case. This enables the cellular network to reduce the load on the primary positioning system and reduce the load caused by the primary positioning system. If the honeycomb network never bypasses the main positioning system, the next step will be to perform the main positioning using the main positioning system. Next, the honeycomb network will decide whether to accept 206 the position estimate reached by the previous main positioning procedure. If the position estimate is acceptable for 206, the front-end operation program 200 then proceeds to return the main positioning position estimate to 208 to the honeycomb network. When the positioning method fails to return the position estimate ' or when the positioning method returns a position estimate with a high degree of uncertainty or error, the position estimate is considered unacceptable. Next, the inertial positioning subsystem 16 updates 2 i 0 with the main positioning position estimate. Then end the 240 front-end operation program 2000. > 11-(8) (8) 200404163 If the honeycomb network decides to bypass the 202 main positioning system, or if the position of the main positioning system is not accepted 2 06, the foreground operation procedure then proceeds to the use of inertial locators The system 16 performs positioning. First, the front-end operating program 200 queries 220 the position of the inertial positioning subsystem in the mobile base station 12; [6. The mobile base station 12 returns to its current position calculated by the background operation program 100. Next, if the position estimation fails to obtain 2 2 2 from the inertial positioning system, the foreground operation procedure returns to the step of performing the main positioning system 2 0 4. Otherwise, the position estimate from the inertial positioning system is returned to the 2 2 4 honeycomb network. Then end the 2 4 0 foreground job program 2 0 0. Referring to FIG. 7, the step of updating the displacement vector 190 in the background operation program 100 starts with projecting the acceleration reading 301 from the sensor array 19 onto the local horizontal plane. Next, project the magnetic field reading 3 02 from the sensor array 19 onto the local horizontal plane. The inclinometer readings are also combined into the projection steps of acceleration 5 3 1 and magnetic field 3 3 2. The basic objective of updating the shift vector step 190 is to obtain north-south, east-west, and vertical components, and then use these 値 to calculate the relative displacement. Here is a calculation example of the projection acceleration reading 3 01 and the magnetic field reading 3 02: Assume that the heading of the mobile base station 12 is in the same direction as the positive direction of its local X axis. Assumptions: τχ = tilt (0) around the X axis of the local horizontal plane.

Ty = tilt (0) around the Y axis of the local horizontal plane. The skew correction transformation matrix is specified as: -12- 200404163

cos pregnant 0 sin Let 0 sin0 sin φ cosd-sin Θ cos φ 0-cos 0 sin 沴 sin6 cos Θ cos 0 0 0 coscf) 0 sin0 0 0 0 10 0 0 — sin umbrella 0 cos0 0 1 0 0 0 1 0 0 0 1 0 0 0 0 0 Assume:

Hx = geomagnetic field along the X axis of the local mobile base station 1 2. Hy = geomagnetic field along the Y axis of the local mobile base station 1 2. Hz == Geomagnetic field along the Z axis of the local mobile base station 1 2. Hx Geomagnetic field along the X axis of the local horizontal plane.

Hy ’= geomagnetic field along the Y axis of the local horizontal plane.

Hz ’= geomagnetic field in the vertical direction. The magnetic field readings for correction of tilt are specified as:-/-/ Ή; Ηχ cos φ ^ Ηζ sin φ Hy = T · 4 sin 0 sin Let ten 7 ^ cos0 — sin 0 cos0 Η: Η: -Ηχ cos θ sin φ + Ηy sin θ · ¥ Ηζ cos θ cos φ _ 1 _ 1 _ 1 L Hypothesis: ax = acceleration along the X axis of the local mobile base station 1 2. ay = acceleration along the Y axis of the local mobile base station 1 2. az = acceleration along the Z axis of the local mobile base station 1 2. h = acceleration along the X axis of the local horizontal plane. ay ’= acceleration along the Y axis of the local horizontal plane. a2 '= acceleration in the vertical direction. The acceleration reading dedicated to correct tilt is specified as: -13- (10) 200404163

ax cos ^ i-a2 sin φ ax sin Θ sin 0 + ay cos0 ~ a2 sin6 cos ^ -qx cos Θ sin 0 + ay sin Θ & a2 cos Θ cos φ a i = acceleration along the north-south direction. a '= acceleration along the east-west direction. ak = acceleration in the local vertical direction (new gravity without ground). Next, from the projected magnetic field reading and the current ground position estimate, the positive azimuth and oblique angle of 303 are calculated. And bevel. Examples of such calculations are listed here: Azimuth (angle between magnetic north and heading direction), α, specified as (calculated α from magnetic north clockwise) Η; α = arctan —v-

Hx oblique angle (the angle between the field vector on the ground and the horizontal plane), (5, specified as: (if pointing down vertically, (5 is positive, otherwise negative)) 〇 = arctan Η:

FJW declination (angle between true north and magnetic north, calculated clockwise from true north), λ, can be calculated using the ground geomagnetic model. This depends on the exact location on the ground and the current time. The deflection angles in small local areas will likely not vary much. For positive bearing, next, calculate the acceleration components in N-S, E-W, and vertical direction 3 0 4. Examples of such calculations are listed here: -14- (11) (11) 200404163 The acceleration along NS / EW is specified as: • cosp -sin β 0 ax / = sin) 8 cos β 0 ay _ 1 _ 0 〇 After L 1 ak ^ az, the relative offset from the initial position of the mobile base station 12 is calculated. Here is an example of such a calculation: Assume: 5 s i == position offset along the north-south direction. 5 s j = position offset along the east-west direction. (5 sk = local vertical position offset. The position offset at time // is specified as: ⑻ = f f2 & »= ί /., (⑽ 2 The present invention provides an improved mobile base station 1 2 Position or positioning system, which includes the main positioning system based on radio and the inertial positioning subsystem 16. This system is an improved system for mobile base stations that currently only rely on radio positioning methods, because when radio positioning cannot be used, its settings A mechanism that provides position estimation. In any case, even when radio position estimation can be used, it can also be used to correct the estimation returned by the inertial positioning system. [Simplified illustration of the drawing] The scope of the patent and the patent application can be more fully understood The invention. • 15 · (12) (12) 200404163 g For detailed description of sheep and patent application scope, please refer to the drawings, the same numbers in the drawings mean similar items in all the drawings. Figure 1 is the outline block of the invention Fig. 2 is a schematic block diagram of the inertial positioning system in Fig. 1. Fig. 3 is a state diagram of a background operation program executed by the processor module of Fig. 2. 4 is an activity diagram of an uninitialized state of a background operation program executed by a processor module according to the present invention. FIG. 5 is an activity diagram of an initialized state of a background operation program executed by a processor module according to the present invention. Fig. 6 is a flowchart of a foreground operation according to the present invention. Fig. 7 is a flowchart of calculating a displacement vector according to the present invention. Component comparison table 12: Mobile communication device 12: Mobile base station 14: Mobile base station Controller 16: Inertial positioning subsystem 19: Sensor array 2 〇: X-axis accelerometer 2 1: y-axis accelerometer 22: z-axis accelerometer 23: X-axis magnetometer 24: y-axis magnetometer-16- (13) (13) 200404163 2 5: Z-axis magnetometer 2 6: X-axis tilt meter 2 7: Y-axis tilt meter 2 8: Temperature sensor 3 0a: Signal filter 3 0b: Signal filter 3 0 c: Signal filter 3 0 d: Signal filter 3 0 e: Signal filter 3 Of: Signal filter 3 0g: Signal filter 3 0 h: Signal filter 3 0 i: Signal filter 40: Processor module

Claims (1)

(1) (1) 200404163, patent application scope, /., An improved method for locating a mobile communication device including a main positioning system and an angry positioning system, the method includes the following steps:, decide whether to bypass the Primary positioning system;-If the primary positioning system is not bypassed, use the primary positioning system to perform positioning; if the primary positioning system is bypassed or if the primary positioning system cannot return an acceptable position estimate, use the inertial positioning The system performs positioning. Xin 2 · If the method of the first scope of the patent application, if the main positioning system is not bypassed, the step of performing positioning using the main positioning system additionally includes the following steps: storing the acceptable position estimate as the main position Estimate; Send the primary position estimate to the inertial positioning system. 3. The method of claim 1 in the scope of patent application, wherein if the main positioning system is bypassed, the step of performing positioning using the inertial positioning system additionally includes the step of sending a positioning request to the inertial positioning system. H 4. The method according to item 1 of the scope of patent application, wherein the inertial positioning system further comprises: a sensor array; and at least one processor module. 5. The method according to item 4 of the patent application scope, wherein the sensor array further comprises: at least three accelerometers, each of which is configured to generate an accelerometer signal; • 18- (2) (2) 200404163 at least three magnetometers, each of which is configured to generate a magnetometer signal; at least two inclinometers, each of which is configured to generate an inclinometer signal; and at least one temperature sensor, Each of the at least one temperature sensor is configured to generate a temperature sensor signal. 6. The method according to item 5 of the patent application, wherein the step of performing positioning using the inertial positioning system further comprises the following steps: reading a sensor signal from the sensor array. 7. A mobile base station including a mobile base station controller and an inertial positioning subsystem; the mobile base station controller is used to control the operation of the mobile base station and to communicate with the cellular network to operate the main positioning system; and The inertial positioning subsystem is used to augment the main positioning system. 8 · The mobile base station according to item 4 of the patent application scope, wherein the inertial positioning subsystem further includes: at least three accelerometers, each of which is configured to generate an accelerometer signal; at least three magnetometers, the Each of the at least three magnetometers is configured to generate a magnetometer signal; at least two inclinometers, each of the at least two inclinometers are configured to generate an inclinometer signal; and at least one temperature sensor 'of the at least one temperature sensor Each is configured to generate a temperature sensor signal; and -19- (3) (3) 200404163 at least one processor module. 9. The mobile base station according to item 5 of the scope of patent application, wherein the at least three accelerometers are used to generate an accelerometer signal characterized by the displacement acceleration of the inertial positioning subsystem. 10. The mobile base station of claim 6 in which the at least three magnetometers generate a magnetometer signal that is characterized by the heading of the inertial positioning subsystem. 11. The mobile base station according to item 5 of the patent application, wherein the at least two inclinometers generate inclinometer signals characterized by the inclination of the inertial positioning subsystem. 12. The mobile base station according to item 5 of the patent application, wherein the temperature sensor generates a temperature sensor signal characterized by the total temperature of the inertial positioning subsystem. 1 3. The mobile base station according to item 5 of the scope of patent application, wherein the processor module is used to determine the position of the inertial positioning subsystem. -20-