Patent Application
20070299626
The above and other features and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.
The term ‘input device,’ as used herein, encompasses not only devices that are currently widely used, such as a presenter, a space mouse for personal computers (PCs), an extension space remote control for digital televisions (TVs), a space input device for three-dimensional (3D) simulation games, a head mounted display (HMD) input device, a pedometer, a vehicle navigator and a vehicle black box, but also all input devices that will be used in the future.
The present invention will hereinafter be described in detail with reference to the accompanying drawings.
Referring to
The transmitter 310 transmits position information of the input device, which is recognized as the input device, such as a presenter, a mouse or a remote control, moves, to the receiver 320 using a wireless communication method. That is, the transmitter 310 measures angular velocity data and acceleration data as the input device moves, calculates Euler angles using the measured angular velocity data and acceleration data, identifies position information of the input device recognized as the input device moves, and transmits the identified position information to the receiver 320 using the wireless communication method.
The transmitter 310 may be configured as illustrated in
Referring to
The inertial measurement module 410 includes an angular velocity sensor 411 and an accelerometer 412 and measures angular velocity data and acceleration data as the input device moves.
The angular velocity sensor 411 measures the angular velocity data as the input device moves. The angular velocity data denotes the rate of change of an angle per unit time which is measured by the angular velocity sensor 411, i.e., a gyroscope. If the angular velocity data is integrated once, an angle can be obtained. Therefore, the angular velocity sensor 411 is definitely required to calculate attitude.
The accelerometer 412 measures the acceleration data as the input device moves. The acceleration data denotes acceleration measured by the accelerometer 412. If the acceleration data is integrated, velocity and distance can be calculated.
As described above, the space recognition apparatus 300 of the input device according to the present embodiment measures the angular velocity data and the acceleration data using the inertial measurement module 410 which integrates the angular velocity sensor 411 and the accelerometer 412.
The main control module 420 calculates the Euler angles using the angular velocity data and the acceleration data measured by the inertial measurement module 410.
As described above, since the transmitter 310 calculates the Euler angles using not only the angular velocity sensor 411 but also the accelerometer 412, the Euler angles can be calculated more accurately.
In addition, since the space recognition apparatus 300 measures angles using the angular velocity sensor 411 and the accelerometer 412 integrated with each other, it can calculate the Euler angles between a reference navigational frame and a body frame instead of calculating angles in the body frame.
Therefore, the space recognition apparatus 300 uses the Euler angles between the reference navigational frame and the body frame instead of the angles in the body frame. Accordingly, the space recognition apparatus 300 can represent the movement of the input device, such as a presenter or a mouse, regardless of the form or attitude in which a user holds the input device. Since the Euler angles refer to angles with respect to a reference frame which is fixed to a ground surface, they can represent absolute angles, and standards for top and bottom/right and left are absolute.
The main control module 420 estimates a bias of the angular velocity sensor 411 using information provided by the accelerometer 412. Therefore, the main control module 420 can mathematically estimate the bias of the angular velocity sensor 411 unlike in a conventional bias estimation method which incurs a dead zone.
The main control module 420 uses a Kalman filtering technique to integrate the angular velocity sensor 411 and the accelerometer 412 and estimate the bias of the angular velocity sensor 411. The Kalman filtering technique is most widely applied in searching for and tracking a moving target. The Kalman filtering technique is a technique for estimating state variables of a linear system and was introduced by Kalman in 1960.
As described above, the space recognition apparatus 300 does not estimate the bias of the angular velocity sensor 411 using conventional activation buttons. Therefore, the space recognition apparatus 300 can perform systematic bias estimation.
The main control module 420 identifies position information of the input device according to the movement of the input device using the calculated Euler angles.
As described above, since the space recognition apparatus 300 can extract information regarding an absolute attitude and the Euler angles, it can perform absolute positioning regardless of the form in which a user holds the input device.
The wireless transmission/reception module 430 transmits the position information to the receiver 320 using the wireless communication method and receives data from the receiver 320 using the wireless communication method.
The key module 440 includes keys required to operate the transmitter 310. When a user presses a key, the key module 440 generates key data corresponding to the pressed key and provides the generated key data to the main control module 420.
The main control module 420 analyzes the key data provided by the key module 440 and controls the transmitter 310 to perform an operation corresponding to the analyzed key data.
The main control module 420 can mathematically calculate and thus prevent drift of the Euler angles. Therefore, even if the main control module 420 is used for a long period of time or minute inputs are continuously added to the main control module 420, it can still perform bias estimation.
The charging module 450 charges a battery that supplies power required to operate the transmitter 310.
As described above, the transmitter 310 of the input device according to the present embodiment calculates the Euler angles with respect to the reference frame using the angular velocity sensor 411 and the accelerometer 412, identifies position information of the input device recognized as the input device moves by using the calculated Euler angles, and transmits the identified position information to the receiver 320 using the wireless communication method.
The receiver 320 receives the position information from the transmitter 310 using the wireless communication method.
Referring to
The wireless transmission/reception module 510 receives the above position information from the transmitter 310 using the wireless communication method and transmits data to the transmitter 310 using the wireless communication method.
The main control module 520 controls the overall operation of the receiver 320 and processes the received position information.
The communication module 530 is linked to a product such as a computer 500, a projector or a TV and includes a universal serial bus (USB) or a serial peripheral interface (SPI) as an interface module for communicating with the linked product. That is, the communication module 530 transmits the position information to the product such as the computer 500, a projector or a TV. Accordingly, the product can identify the movement of the input device, such as a presenter, a mouse or a remote control, in space based on the position information received from the communication module 530 and display the identified movement on a screen thereof.
As described above, the space recognition apparatus 300 of the input device according to the present embodiment can form a six degree-of-freedom navigation system using the angular velocity sensor 411 and the accelerometer 412, calculate the Euler angles with respect to the reference frame, and recognize the movement of the input device, such as a presenter, a mouse or a remote control, in space.
Therefore, the transmitter 310 of the space recognition apparatus 300 transmits position information of the input device identified according to the movement of the input device to the receiver 320 using the wireless communication method, and the receiver 320 transmits the received position information to a product such as the computer 500, a projector or a TV. Accordingly, the space recognition apparatus 300 can be used as an information input device for the product.
Referring to
In this case, operation 610 in which the angular velocity data is measured using the angular velocity sensor and operation 620 in which the acceleration data is measured using the accelerometer may be performed sequentially or simultaneously.
In operation 630, the input device estimates the bias of the angular velocity sensor using the angular velocity data measured by the accelerometer.
Alternatively, in operation 630, the input device may estimate the bias of the angular velocity sensor using the Kalman filtering technique. The Kalman filtering technique is also used to integrate the angular velocity sensor and the accelerometer.
As described above, since the space recognition method of the input device according to the present embodiment estimates the bias of the angular velocity sensor using information provided by the accelerometer, it can mathematically estimate the bias of the angular velocity sensor unlike in the conventional bias estimation method which gives a dead zone.
Furthermore, the drift of the Euler angles can be mathematically calculated and thus prevented. Accordingly, even if the input device is used for a long period of time or minute inputs are continuously added to the input device, bias estimation can still be performed.
In addition, since the bias of the angular velocity sensor can be mathematically corrected using the space recognition method, the bias phenomenon of the angular velocity sensor can be eliminated.
In operation 640, the input device calculates the Euler angles using the measured angular velocity data and acceleration data. That is, in operation 640, the input device calculates the Euler angles between a reference navigational frame and a body frame using the measured angular velocity data and acceleration data.
As described above, since the space recognition method calculates the Euler angles using the angular velocity data and the acceleration data, the Euler angles can be calculated more accurately.
In operation 650, the input device identifies its position information according to its movement by using the calculated Euler angles. The input device transmits the identified position information to a receiver, which is linked to a product such as a computer, a projector or a TV, using a transmitter and a wireless communication method. Then, the receiver transmits the received position information to the linked product. Since the product receives the position information from the input device having a space recognition function, it can use the input device as an information input device.
As described above, the space recognition method uses the Euler angles between the reference navigational frame and the body frame instead of angles in the body frame. Accordingly, the movement of the input device, such as a presenter or a mouse, can be represented regardless of the form or attitude in which a user holds the input device.
In addition, since the space recognition method measures angles using the angular velocity sensor and the accelerometer integrated with each other, it can measure the Euler angles between the reference navigational frame and the body frame instead of the angles in the body frame. Accordingly, information regarding an absolute attitude and the Euler angles can be extracted. Consequently, the input device can perform absolute positioning regardless of the form in which a user holds the input device.
The space recognition method according to the present invention includes a computer-readable medium. The computer-readable medium stores program commands that are operable in various computers. The computer-readable medium can store program commands, data files, and data structures, or combining those. The program command of the medium is specially designed and configured, or is notified to those skilled in the art for use. The computer-readable recording medium includes a magnetic media (such as a hard disk, a floppy disk, and magnetic tape), an optical media (such as CD-ROM and DVD), a magneto-optical media (such as floptical disk), and also ROM, RAM, and flash memory. Moreover, the computer-readable recording medium includes a hardware device for storing and performing the program commands. The medium can be a transmission medium such as a light or metal line, and a waveguide pipe including carrier that transmits a signal indicating program commands and data structures. The program commands can be a machine language code by a compiler and a high-level programming language code by an interpreter, which can be executable in the computer.
As described above, the present invention can form a six degree-of-freedom navigation system using an angular velocity sensor and an accelerometer, calculate Euler angles with respect to a reference frame, and recognize the movement of an input device, such as a presenter, a mouse or a remote control, in space.
In addition, the present invention can prevent angle divergence using both the angular velocity sensor and the accelerometer and measure absolute angles, thereby improving angle accuracy.
Since the present invention uses the Euler angles between a reference navigational frame and a body frame instead of angles in the body frame, it can represent the movement of the input device, such as a presenter or a mouse, regardless of the form or attitude in which a user holds the input device.
Also, the present invention can mathematically correct the bias of the angular velocity sensor using the accelerometer.
Last, since the present invention can measure the Euler angles between the reference navigational frame and the body frame instead of the angles in the body frame, it can extract information regarding an absolute attitude and the Euler angles. Consequently, the input device can perform absolute positioning regardless of the form in which the user holds the input device.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0055760 | Jun 2006 | KR | national |
