TWI392848B - Method for identifying the orientation and navigation apparatus using the same - Google Patents

Description

Position recognition method and navigation device thereof

The present invention relates to an orientation determination technique for setting an electronic device, and more particularly to an orientation recognition method for identifying a navigation device setting and a navigation device using the same.

As shown in FIG. 1, the figure is a schematic diagram of a conventional global position system (GPS) and inertial navigation system. In the conventional technique, the global positioning and inertial navigation system 10 is fixedly disposed on the instrument panel 11 in a vehicle (for example, a vehicle). Since the system of Fig. 1 is fixedly mounted in the vehicle, there is no maneuverability for the user to utilize the space. In recent years, with the civilianization of the price of inertial originals, the future global positioning and inertial navigation system has gradually spread in PDAs or mobile phones.

Since portable electronic products such as PDAs or mobile phones are small in size and easy to carry, users can install them anywhere in the car as they like. However, there are several problems to be overcome in the use of the vertical and horizontal directions. The first is to determine the rotational orientation to adjust the image display direction. The second is that when the direction of use of global positioning and inertial navigation system changes, the acceleration and angular velocity detection axes in the inertial navigation module in the global positioning and inertial navigation system also have a standard conversion relationship with the original geodetic reference coordinates. At this time, if no coordinate conversion correction is made, the inertial navigation module will not work properly.

The technology for judging the working position of the system is currently applied to handheld games. A 3D space game environment is described in the US Patent No. 6,908,388, which includes a housing for the user to grab, a tilt sensor within the housing, and an observation point coordinate determination mechanism. The observation coordinates are judged along with the output signal of the tilt sensor. A game image generation processing mechanism generates a game image based on the determined coordinates. The game system can provide a user with a feeling that the 3D game space varies with the tilt of the game device with a minimum processing load. A 3D indicating device including a dual-axis gyroscope and an accelerometer and a processing unit is also described in the U.S. Patent No. 7,158,118, which is sensed by a first reference surface (for example, a body of a 3D indicator device). The motion information is converted to a second reference plane (eg, a user reference plane), primarily to eliminate the angular tilt effect of the handheld 3D indicator device. Simply put, it is an inertial component attitude detection that reuses coordinate transformation to eliminate the effects of tilt. However, in the aforementioned conventional techniques, there is no specific and effective method for how to overcome the above two problems.

The invention provides a method for setting azimuth identification, which is applied in a portable navigation device. The method mainly determines that the positioning position of the navigation device is vertical or horizontal according to the acceleration value measured by the accelerometer in the first direction and the second direction, and performs corresponding coordinate conversion, so that the navigation device is not affected by the working orientation. Maintain normal work.

The present invention further provides a navigation device that uses the above-described set orientation recognition method to identify the orientation of the navigation device and detect the coordinate position of the navigation device to provide user location and traffic information.

In one embodiment, the present invention provides a method for setting an orientation, comprising the steps of: providing a navigation device having a steering sensing module and a first accelerometer for sensing a first directional acceleration; Sensing a second accelerometer of a second direction acceleration; capturing a first accelerometer of the navigation device and an acceleration value output by the second accelerometer; and according to the first accelerometer and the second accelerometer The output acceleration value is compared with an identification information to determine a set orientation of the navigation device, wherein the identification information is that the first accelerometer and the second accelerometer should theoretically feel when the navigation device is turned to a specific set orientation. The measured acceleration value.

In another embodiment, the present invention further provides a navigation device, comprising: an inertial navigation unit having a first accelerometer, a second accelerometer, a third accelerometer, and an angular velocity sensing module; a satellite signal receiving unit for receiving a satellite signal; and a signal processing unit coupled to the inertial navigation unit and the satellite signal receiving unit, the signal processing unit being responsive to the first accelerometer and the first The acceleration value output by the two accelerometers is compared with an identification information to determine a set orientation of the navigation device and output a target position according to the inertial navigation unit and the satellite signal, wherein the identification information is when the navigation device is turned to a specific The first accelerometer and the second accelerometer should theoretically sense the acceleration value when the orientation is set.

In another embodiment, the present invention further provides a navigation device that can be disposed in a vehicle and adjusts its orientation according to the needs of use. The navigation device includes: an inertial navigation unit having a first Accelerometer, a second accelerometer, a third accelerometer, and an angular velocity a sensing module; a satellite signal receiving unit for receiving a satellite signal; a signal processing unit coupled to the inertial navigation unit and the satellite signal receiving unit, the signal processing unit being The accelerometer and the acceleration value output by the second accelerometer are compared with an identification information to determine a set orientation of the navigation device and output a landmark position according to the inertial navigation unit and the satellite signal, wherein the identification information is for navigation The first accelerometer and the second accelerometer should theoretically sense an acceleration value when the device is turned to a specific set orientation; a database coupled to the signal processing unit, the database being built There is map and road traffic information; and a display device is connected to the signal processing unit, and the display device displays information provided by the database.

In order to enable the reviewing committee to have a further understanding and understanding of the features, objects and functions of the present invention, the related detailed structure of the device of the present invention and the concept of the design are explained below so that the reviewing committee can understand the present invention. Features, detailed descriptions are as follows:

Referring to FIG. 2, the figure is a block diagram of an embodiment of a navigation device of the present invention. The navigation device 2 can be disposed in a vehicle (for example, a wheeled vehicle). The navigation device 2 mainly includes an inertia navigation system (INS) and a satellite signal receiving unit 21 (global). Position system, GPS) and a signal processing unit 22. The inertial navigation unit 20 is capable of measuring the acceleration state of the three axes in the space and the rotation state of the navigation device. In this implementation In an example, the inertial navigation unit 20 has a first accelerometer 201 that detects acceleration of the first axis (X-axis) and a second accelerometer 202 that detects the third axis (Z-axis). Acceleration, a third accelerometer 203, which can detect the acceleration of the second axis (Y axis) and an angular velocity sensing module 204, which can sense the rotational speed of the first axis (X axis) and the third The speed of the shaft (Z axis).

Although the embodiment of FIG. 2 utilizes three accelerometers 201, 202, and 203, due to advances in semiconductor manufacturing, it is also possible to implement a single accelerometer that integrates three accelerometers to sense the motion state of the three axes. This is a technique that is familiar to those skilled in the art and can be readily substituted in accordance with the teachings of the present invention. The acceleration of the second axis (Y axis) represents the acceleration of the vehicle forward or backward, and the first axis rotation speed can represent the angular velocity of the vehicle inclination, and the third axis (Z axis) rotation speed can represent The angular velocity of the left and right steering of the vehicle.

As shown in FIG. 3A, the figure is a block diagram of a first embodiment of the angular velocity sensing module of the present invention. In the present embodiment, the angular velocity sensing module 204 is configured by two gyro sensors 2041 and 2042 to sense the rotational speeds of the X-axis and the Z-axis, respectively. The technique of sensing angular velocity using a gyro sensor is a conventional technique and will not be described herein. As shown in FIG. 3B, the figure is a block diagram of a second embodiment of the angular velocity sensing module of the present invention. In this embodiment, the angular velocity sensing module 204 has a gyro sensor 2043 to sense the rotational speed of the X-axis. The rotational speed of the Z-axis is responsible for a differential module 2044 having a pair of accelerometers 2051 and 2052 at a distance. The pair of accelerometers 2051 and 2052 sense one acceleration change in the same axial direction, and the rotation state of the first axis is obtained by using the difference. As shown in FIG. 4, the figure is a schematic diagram of the angular velocity sensing of the present invention. In the figure, when the accelerometer 2051 and the accelerometer 2052 sense the first axis (X-axis) acceleration signal integral, the displacement (S ₁ , S ₂ ) can be obtained, and then the difference between S ₁ and S _{2 is} estimated, because Since the accelerometer 2051 and the accelerometer 2052 are separated by a distance h, the angle θ of the third axis (Z-axis) can be calculated by calculation.

Please refer to FIG. 3C, which is a schematic diagram of a third embodiment of the angular velocity sensing module of the present invention. In this embodiment, the angular velocity sensing module 204 is composed of two differential modules 2045 and 2046. Each differential module 2045 or 2046 has a pair of accelerometers 2053 and 2054 and 2055 and 2056, each pair. The accelerometers 2053 are separated from the 2054 or 2055 by 2056 by a distance. The differential module 2045 can calculate the rotational speed of the first axis (X axis) by using the difference by sensing the acceleration change of the same axial direction (Z axis), and the other differential module 2046 can sense the same by sensing The acceleration of the axial direction (X-axis) is measured to calculate the rotational speed of the third axis (Z-axis) by using the difference calculation.

As shown in FIG. 3D, the figure is a schematic diagram of a fourth embodiment of the angular velocity sensing module of the present invention. In the embodiment, the angular velocity sensing module 204 has a first auxiliary accelerometer 2047 and a second auxiliary accelerometer 2048. Referring to FIG. 3D and FIG. 2 , the first auxiliary accelerometer 2047 is at a distance from the first accelerometer 201 , and the first accelerometer 201 and the first auxiliary accelerometer 2047 . One of the acceleration changes is sensed, and the difference is used to obtain the rotation state of the third axis (Z axis). The second auxiliary accelerometer 2048 is at a distance from the second accelerometer 202. The second accelerometer 202 and the second auxiliary accelerometer 2048 sense one acceleration change, and use the difference to obtain the first The rotation state of the shaft (X axis).

Returning to Figure 2, the satellite signal receiving unit 21 receives a satellite signal. The satellite signal receiving unit 21 is a conventional technical component of the global positioning system, and is not described herein. The signal processing unit 22 is coupled to the inertial navigation unit 20 and the satellite signal receiving unit 21, and the signal processing unit 22 is capable of outputting acceleration according to the first accelerometer 201 and the second accelerometer 202. The value is compared with an identification information to determine the set orientation of the navigation device 2 and to output a target position based on the inertial navigation unit 20 and the satellite signal.

Next, the operation method of the signal processing unit will be described. As shown in FIG. 5, the figure is a schematic flow chart of the method for setting the orientation of the present invention. The method mainly includes the following steps: First, step 40 is performed to extract the acceleration values output by the first accelerometer and the second accelerometer. The first accelerometer can sense the acceleration in the X-axis direction, and the second accelerometer can sense the acceleration in the Z-axis direction. Returning to FIG. 5, step 41 is further performed, and the acceleration value output by the first accelerometer and the second accelerometer is compared with an identification information to determine a set orientation of the navigation device. As shown in FIG. 2, the identification information can be stored in a memory unit 23, and the memory unit 23 is coupled to the signal processing unit 22. In general, the memory unit 23 can be selected as a conventional memory component, which is not a part of the prior art.

Due to the orientation of the navigation device 2, the acceleration sensed by the first accelerometer and the second accelerometer changes. For example, as shown in FIG. 6A, the figure is a schematic diagram of the navigation device 2 in an upright state. The block of Fig. 2 is disposed within the housing 26 of the navigation device of Fig. 6A, and the various accelerometers are only indicated by reference numerals in Fig. 6A. In the state of Figure 6A, due to gravity The action of G, therefore the second accelerometer 202 can sense the gravitational acceleration. On the contrary, as shown in FIG. 6B, the figure is a schematic diagram of the lateral arrangement of the navigation device. When the navigation device is turned clockwise to the state of FIG. 6B via FIG. 6A, since the orientations of the first accelerometer 201 and the second accelerometer 202 are changed, the first accelerometer 201 is sensed by the gravitational acceleration at this time. The sensed gravitational acceleration value is positive. In addition, when the navigation device is flipped to the state of FIG. 6C via the counterclockwise direction via FIG. 6A, since the orientations of the first accelerometer 201 and the second accelerometer 202 are changed, the first acceleration of the gravitational acceleration is sensed at this time. In 201, the sensed gravitational acceleration value is a negative value. It should be emphasized that although the foregoing gravity acceleration is used as an illustrative embodiment, this is the case when the vehicle is traveling on a flat road (ie, the vehicle inclination is zero degrees). If the vehicle has an inclination, for example, ups and downs or up and down, the sensed acceleration value should be a trigonometric relationship of gravity acceleration. This is familiar to those skilled in the art and will be apparent from the teachings of the present invention.

Returning to FIG. 5, since the acceleration values detected by the first accelerometer and the second accelerometer change when the orientation of the navigation device changes, the detected value and the pre-existence may be present in step 41. The identification information in the memory unit is compared, and then the set orientation state of the navigation device is determined. The identification information is an acceleration value that the first accelerometer and the second accelerometer should theoretically sense when the navigation device is turned to a specific set orientation, for example, when the erect state of FIG. 6A is sensed, The gravitational acceleration is the second accelerometer 202. If it is the state of FIG. 6B, the gravitational acceleration is sensed by the first accelerometer 201, and the sensed gravitational acceleration value is a positive value. If it is the state of Figure 6C, it is sensed to be heavy The force acceleration is the first accelerometer 201, and the sensed gravitational acceleration value is a negative value. Therefore, after the comparison of step 41, the orientation set by the navigation device can be immediately determined. Finally, after determining the orientation set by the navigation device (as shown in FIG. 6A, FIG. 6B or FIG. 6C), step 42 is performed to re-convert the coordinate axis direction of the inertial navigation unit.

When the navigation device is switched from the upright setting to the lateral setting or from the lateral setting to the upright setting, the physical quantity sensed by the inertial navigation unit therein changes when it corresponds to the absolute coordinate system. This is because the sensor in the original inertial navigation unit responsible for detecting the steering and tilt of the vehicle changes as the position of the navigation device changes. For example, in FIG. 6A, the first axis x' thereof coincides with the first axis X of the absolute coordinate system 90, and the measured rotational speed ω x' with respect to the first axis represents the inclination of the vehicle, and in addition, the third axis z The 'the line coincides with the third axis Z of the absolute coordinate system 90, and the resulting rotational speed ω z' with respect to the third axis represents the steering of the vehicle. However, when going to the state of Figure 6B, the original first axis x' will coincide with the third axis Z of the absolute coordinate system, so the detected rotational speed ω x ' represents the steering of the vehicle instead of the original Vehicle inclination. Similarly, the original third axis z' coincides with the first axis X of the absolute coordinate system 90, so the detected rotational speed ω z' represents the inclination of the vehicle rather than the original steering angle.

Because of the above changes, in order to maintain the normal operation of the navigation device, step 42 is required to re-convert the coordinate axis direction of the inertial navigation unit. That is, the system will give different judgments on the sensed rotation state according to the orientation of the navigation device. For example, taking the angular velocity sensing module of FIG. 3A as an example, when the navigation device is in the state of FIG. 6A, the rotational speed detected by the gyroscope sensor 2041 represents an absolute coordinate system. The X-axis rotational speed in 90 also represents the inclination of the vehicle, and the rotational speed detected by the gyro sensor 2042 represents the Z-axis rotational speed of the absolute coordinate 90, that is, represents the steering of the vehicle. After determining the set orientation of the navigation device by step 41, coordinate conversion is performed through step 42, that is, when the navigation device is changed from upright to horizontal, the signal detected by the gyro sensor 2041 will be Corresponds to the rotational speed of the Z coordinate of the absolute coordinate, reflecting the steering of the vehicle. Similarly, the signal detected by the gyro sensor 2042 corresponds to the rotational speed of the X coordinate of the absolute coordinate, reflecting the inclination of the vehicle. Since the rotational speed detected by the same gyro sensor 2041 or 2042 has different physical meanings as the orientation of the navigation device changes, the coordinate conversion of step 42 is extremely important.

Referring to FIG. 2, the navigation device further has a map database 24 and a display device 25. The map database 24 is coupled to the signal processing unit 22, and the map database 24 is provided with map and road traffic information. The display device 25 is connected to the signal processing unit 22, and the display device 25 displays the information provided by the database 22. The display device 25 can display an area map corresponding to the coordinate position, and display a mark on the map to identify the location where the user is located. In addition, the signal processing unit 22 plans a driving route based on the coordinate position and the destination to which the user inputs the destination, and displays the driving route on the display device 25.

However, the above is only an embodiment of the present invention, and the scope of the present invention is not limited thereto. It is to be understood that the scope of the present invention is not limited by the spirit and scope of the present invention, and should be considered as a further embodiment of the present invention.

In summary, the method for setting azimuth and the navigation device provided by the present invention can determine the setting position of the navigation device and can convert the coordinate system according to the set orientation of the setting to maintain the operation of the navigation device. The features of the present invention can improve the competitiveness of the industry and promote the development of the surrounding industries. Cheng has already met the requirements for applying for inventions as stipulated by the invention patent law. Therefore, the application for invention patents is submitted according to law. Allow time to review and grant patents as prayers.

10‧‧‧Global Positioning and Inertial Navigation System

11‧‧‧Dashboard

2‧‧‧Navigation device

20‧‧‧Inertial navigation unit

201‧‧‧First accelerometer

202‧‧‧Second accelerometer

203‧‧‧ Third accelerometer

204‧‧‧Angle speed sensing module

2041, 2042, 2043 ‧ ‧ gyroscope sensor

2044, 2045, 2046‧‧‧Differential Module

2051~2056‧‧‧Accelerometer

2047‧‧‧First auxiliary accelerometer

2048‧‧‧Second auxiliary accelerometer

21‧‧‧ Satellite signal receiving unit

22‧‧‧Signal Processing Unit

23‧‧‧ memory unit

24‧‧‧Map Database

25‧‧‧ display device

4‧‧‧Set azimuth identification method

40~42‧‧‧Steps

90‧‧‧Absolute coordinate system

Figure 1 is a schematic diagram of a conventional global position system (GPS) and inertial navigation system.

2 is a block diagram showing an embodiment of a navigation device of the present invention.

FIG. 3A is a block diagram showing the first embodiment of the angular velocity sensing module of the present invention.

FIG. 3B is a block diagram showing a second embodiment of the angular velocity sensing module of the present invention.

FIG. 3C is a schematic diagram of a third embodiment of the angular velocity sensing module of the present invention.

FIG. 3D is a schematic diagram of a fourth embodiment of the angular velocity sensing module of the present invention.

Figure 4 is a schematic diagram of the angular velocity sensing of the present invention.

FIG. 5 is a schematic flow chart of the method for setting the orientation of the present invention.

Figure 6A is a schematic diagram of the navigation device in an upright state.

Figure 6B and Figure 6C are schematic diagrams of the lateral arrangement of the navigation device.

2‧‧‧Navigation device

20‧‧‧Inertial navigation unit

201‧‧‧First accelerometer

202‧‧‧Second accelerometer

203‧‧‧ Third accelerometer

204‧‧‧Angle speed sensing module

21‧‧‧ Satellite signal receiving unit

22‧‧‧Signal Processing Unit

23‧‧‧ memory unit

24‧‧‧Map Database

25‧‧‧ display device

Claims (19)

A method for setting azimuth includes the following steps: providing a navigation device having a steering sensing module and a first accelerometer for sensing a first direction acceleration and sensing one of the second direction accelerations a second accelerometer; the first accelerometer of the navigation device and the acceleration value output by the second accelerometer; and the acceleration value outputted by the first accelerometer and the second accelerometer and an identification information Comparing to determine a set orientation of the navigation device, wherein the identification information is an acceleration value that the first accelerometer and the second accelerometer should theoretically sense when the navigation device is turned to a specific set orientation. The method for determining the orientation of the navigation device according to claim 1, wherein determining the orientation of the navigation device further comprises the steps of: determining whether the acceleration value sensed by the first accelerometer is an azimuth acceleration value, and if so Then, the setting orientation of the navigation device is a straight orientation setting; and determining whether the acceleration value sensed by the second accelerometer is an azimuth acceleration value, and if so, representing that the setting orientation of the navigation device is a lateral setting. The method for setting azimuth according to claim 2, wherein the azimuth acceleration value is a function of gravity acceleration and a tilt angle of the navigation device. The method for setting azimuth according to item 1 of the patent application scope is The method further includes the step of converting the sensing coordinate axis of the steering sensing module according to the identification result. The method for setting azimuth according to claim 1, wherein the identification information is stored in a memory unit. A navigation device includes: an inertial navigation unit having a first accelerometer, a second accelerometer, a third accelerometer, and an angular velocity sensing module, wherein the first accelerometer detects the first axis Acceleration, the second accelerometer detects acceleration of the third axis, the third accelerometer detects acceleration of the second axis; a satellite signal receiving unit receives a satellite signal; and a signal processing unit is coupled thereto The first accelerometer, the second accelerometer, the third accelerometer, the angular velocity sensing module, and the satellite signal receiving unit are coupled to each other, and the signal processing unit is responsive to the first accelerometer and the second acceleration The acceleration value outputted by the meter is compared with an identification information to determine a set orientation of the navigation device and output a target position according to the inertial navigation unit and the satellite signal, wherein the identification information is when the navigation device is turned to a specific set orientation The first accelerometer and the second accelerometer should sense the acceleration value. The navigation device of claim 6, wherein the angular velocity sensing module is a gyroscope sensing module that outputs an angular velocity of the first axis and an angular velocity signal of the third axis. The navigation device of claim 6, wherein the angular velocity The sensing module has: a differential module having a pair of accelerometers, the pair of accelerometers being separated by a distance, and the pair of accelerometers sense one of the acceleration changes, and the difference is used to obtain the rotation state of the first axis; And a gyroscope sensor that senses the angular velocity of the third axis. The navigation device of claim 6, wherein the angular velocity sensing module has: a first differential module having a pair of accelerometers, the pair of accelerometers being separated by a distance, by the pair of accelerations Measuring one of the acceleration changes, using the difference to obtain the rotational state of the first axis; and the second differential module having a pair of accelerometers, the pair of accelerometers being separated by a distance, by the pair of accelerometers One of the acceleration changes is measured, and the difference is used to obtain the rotation state of the third axis. The navigation device of claim 6, further comprising a memory unit for storing the identification information. The navigation device of claim 6, wherein the angular velocity sensing module has: a first auxiliary accelerometer, which is at a distance from the first accelerometer, by the first accelerometer and the first An auxiliary accelerometer senses one of the acceleration changes, the difference is used to obtain a rotation state of the third axis; and the second auxiliary accelerometer is at a distance from the second accelerometer by the second accelerometer and the The second auxiliary accelerometer senses one of the acceleration changes, and uses the difference to obtain the first axis of rotation Dynamic state. A navigation device that can be disposed in a vehicle and adjusts its orientation according to needs. The navigation device includes: an inertial navigation unit having a first accelerometer, a second accelerometer, and a third An accelerometer and an angular velocity sensing module, wherein the first accelerometer detects acceleration of the first axis, the second accelerometer detects acceleration of the third axis, and the third accelerometer detects acceleration of the second axis, The acceleration of the second axis is the acceleration of the vehicle forward or backward; a satellite signal receiving unit receives a satellite signal; a signal processing unit is coupled to the first accelerometer, the second accelerometer, and the The third accelerometer, the angular velocity sensing module and the satellite signal receiving unit are coupled to each other, and the signal processing unit can compare the acceleration value output by the first accelerometer and the second accelerometer with an identification information. Determining a set orientation of the navigation device and outputting a target position according to the inertial navigation unit and the satellite signal, wherein the identification information is The acceleration value that the first accelerometer and the second accelerometer should sense when the navigation device is turned to a specific set orientation; a database coupled to the signal processing unit, the database is internally established Map and road traffic information; and a display device coupled to the signal processing unit, the display device displaying information provided by the database. The navigation device of claim 12, wherein the angular velocity The degree sensing module is a gyroscope sensing module that outputs an angular velocity of the first axis and an angular velocity signal of the third axis. The navigation device of claim 12, wherein the angular velocity sensing module comprises: a differential module having a pair of accelerometers, the pair of accelerometers being separated by a distance, by the pair of accelerometers Sensing one of the acceleration changes, using the difference to obtain the rotational state of the first axis; and a gyroscope sensor that senses the angular velocity of the third axis. The navigation device of claim 12, wherein the angular velocity sensing module has: a first differential module having a pair of accelerometers, the pair of accelerometers being separated by a distance, by the pair of accelerations Measuring one of the acceleration changes, using the difference to obtain the rotational state of the first axis; and the second differential module having a pair of accelerometers, the pair of accelerometers being separated by a distance, by the pair of accelerometers One of the acceleration changes is measured, and the difference is used to obtain the rotation state of the third axis. The navigation device of claim 12, further comprising a memory unit for storing the identification information. The navigation device of claim 12, wherein the angular velocity sensing module has: a first auxiliary accelerometer, which is at a distance from the first accelerometer, wherein the first accelerometer and the first An auxiliary accelerometer senses one of the acceleration changes, and uses the difference to obtain the rotational state of the third axis; The second auxiliary accelerometer is at a distance from the second accelerometer, and the second accelerometer and the second auxiliary accelerometer sense one of the acceleration changes, and the difference is used to obtain the rotation state of the first axis. The navigation device of claim 12, wherein the positioning mark is displayed on the display device according to the coordinate position. The navigation device of claim 12, wherein the signal processing unit displays a one-way route on the display device according to the coordinate position.