JP4151983B2 - Moving direction calculation device and moving direction calculation program - Google Patents

Description

  The present invention relates to a movement direction calculation device and a movement direction calculation program, and more particularly to a movement direction calculation device and a movement direction calculation program for calculating the movement direction of an input device.

Patent Document 1 describes a technique for detecting the movement of a controller simulating a glove worn on a hand. This controller includes an acceleration sensor, and each acceleration value in the three-axis directions is detected by the acceleration sensor. Then, based on the detected waveform pattern of each acceleration value, the movement of the controller (that is, the type of punch) is determined.
JP 2002-153673 A

  The controller described in Patent Document 1 can only classify punches into several types according to the waveform pattern, and cannot determine the movement direction of the controller in detail. For this reason, since the types of operations that can be input by the player are limited to several types, the content of the game is simplified, and the game may not be interesting.

  Therefore, an object of the present invention is to provide a movement direction calculation device and a movement direction calculation program capable of accurately calculating the movement direction of an input device.

  The present invention employs the following configuration in order to solve the above problems. Note that the reference numerals in parentheses and supplementary explanations in this section show the correspondence with the embodiments described later in order to help understanding of the present invention, and do not limit the present invention.

  1st invention is the movement direction calculation apparatus (game device 3) which calculates the movement direction of an input device (controller 7). The moving direction calculation device includes an acquisition unit (CPU 10 or the like that executes step S2; hereinafter, only the step number is described in the same case in this column), a period detection unit (S4, S7), and a difference calculation unit. (S23) and a moving direction calculation means (S24). The acquisition means sequentially acquires acceleration data (621) output from the multi-axis acceleration sensor (37) mounted on the input device. The period detection means detects a period from when the input device starts to move until the movement ends as a movement period based on the acquired acceleration data. The difference calculating means is configured to select a plurality of acceleration data (selected) within a moving period when a vector having acceleration components related to a plurality of axes among the acceleration values related to each axis indicated by the acceleration data is used as an acceleration vector. For each acceleration data group 631), a difference vector between the acceleration vector corresponding to the acceleration data and the acceleration vector corresponding to the acceleration data acquired next to the acceleration data is calculated. The moving direction calculating means weights each difference vector calculated for each acceleration data acquired within the moving period according to the magnitude of the difference vector, calculates the sum of the difference vectors, and calculates the sum The direction determined by the vector indicated by is the moving direction.

  In the second invention, the period detection means may include a start setting means (S4) and an end setting means (S7). The start setting means sets a time point at which an acceleration value related to a predetermined one axis (z axis) among acceleration values related to each axis indicated by the acceleration data stored in the memory exceeds a first threshold value as a start time of the movement period. To do. The end setting means sets, as the end point of the movement period, the time point when the acceleration value related to a predetermined one axis among the acceleration values related to each axis indicated by the acceleration data stored in the memory falls below the second threshold value.

  In the third invention, the multi-axis acceleration sensor may be a three-axis acceleration sensor. At this time, the difference calculation means uses, as an acceleration vector, a vector having acceleration components related to two axes other than the predetermined one axis as acceleration components among the acceleration values related to each axis indicated by the acceleration data.

  In the fourth invention, the movement direction calculating device may further include gravity direction calculating means (S25) and game processing means (S9). The gravity direction calculation means calculates a vector indicating the sum of the acceleration vectors corresponding to the plurality of acceleration data acquired within the movement period as the gravity direction applied to the input device. The game processing means executes a predetermined game process based on the moving direction and the gravity direction.

  Further, the present invention may be provided in the form of a movement direction calculation program (game program 61) for causing the computer of the movement direction calculation apparatus to execute the above-described operation.

  According to the first aspect, a difference vector is calculated for each piece of acceleration data acquired during the movement period. Then, the moving direction is calculated by weighting the difference vector and calculating the sum. Here, in the method of calculating the sum of the difference vectors without weighting, there is a possibility that the first moving direction cannot be accurately recognized depending on the detection result of the predetermined period. For example, if the value of the acceleration data acquired first within a predetermined period and the value of the acceleration data acquired last are substantially the same, the sum is almost “0”. The direction of movement cannot be recognized accurately. On the other hand, according to the first invention, since the sum is calculated in consideration of the weights, the values of the two acceleration data acquired first and last in the predetermined period are the same. However, the vector indicating the sum is not “0”. According to the first aspect, among the difference vectors, the component of the difference vector having a relatively large size is represented by the sum, and the first movement direction can be accurately calculated.

  According to the second invention, it is possible to easily detect the start time and end time of the period during which the input device is moving.

  According to the third aspect of the invention, the movement period can be easily detected using the acceleration value related to the predetermined one axis of the three-axis acceleration sensor, and the acceleration value related to two axes other than the predetermined one axis is used. Thus, the moving direction with respect to the two axis directions can be easily calculated.

  According to the fourth aspect, not only the moving direction but also the direction of gravity applied to the input device is calculated. That is, from the acceleration data acquired from the input device, two types of information indicating the state of the input device, the moving direction and the gravity direction, are calculated. Then, the game apparatus performs game processing by reflecting these two types of information in the game operation. Therefore, according to the fourth invention, it is possible to cause the player to perform a complicated game operation based on the two types of states of the input device while having a simple configuration with one sensor.

  With reference to FIG. 1, a game system 1 including a game apparatus which is an example of a moving direction calculation apparatus according to an embodiment of the present invention will be described. FIG. 1 is an external view of the game system 1. Hereinafter, a game apparatus and a game program will be described using a stationary game apparatus as an example.

  In FIG. 1, a game system 1 is a stationary game apparatus (hereinafter simply referred to as a game) connected to a display (hereinafter referred to as a monitor) 2 having a speaker such as a home television receiver via a connection cord. 3) and a controller 7 for giving operation data to the game apparatus 3. Also, two markers 8a and 8b are installed around the monitor 2 (upper side of the screen in the figure). The markers 8a and 8b are specifically infrared LEDs, and output infrared light toward the front of the monitor 2, respectively. The game apparatus 3 is connected to the receiving unit 6 via a connection terminal. The receiving unit 6 receives operation data wirelessly transmitted from the controller 7, and the controller 7 and the game apparatus 3 are connected by wireless communication. In other embodiments, the controller 7 and the game apparatus 3 may be connected by wire. Further, an optical disk 4 that is an example of an information storage medium that can be used interchangeably with the game apparatus 3 is attached to and detached from the game apparatus 3. The upper main surface of the game apparatus 3 is provided with a power ON / OFF switch of the game apparatus 3, a reset switch for game processing, and an OPEN switch for opening the lid on the upper part of the game apparatus 3. Here, when the player presses the OPEN switch, the lid is opened, and the optical disk 4 can be attached and detached.

  Further, an external memory card 5 equipped with a backup memory or the like for storing save data or the like in a fixed manner is detachably attached to the game apparatus 3 as necessary. The game apparatus 3 displays a result as a game image on the monitor 2 by executing a game program or the like stored on the optical disc 4. Furthermore, the game apparatus 3 can reproduce the game state executed in the past by using the save data stored in the external memory card 5 and display the game image on the monitor 2. Then, the player of the game apparatus 3 can enjoy the progress of the game by operating the controller 7 while viewing the game image displayed on the monitor 2.

  The controller 7 wirelessly transmits operation data from a communication unit 36 (described later) provided therein to the game apparatus 3 to which the receiving unit 6 is connected, using, for example, Bluetooth (registered trademark) technology. The controller 7 is provided with an operation unit including a plurality of operation buttons. Further, as will be apparent from the description below, the controller 7 includes an acceleration sensor 37 (described later) that detects linear acceleration. Data indicating the acceleration detected by the acceleration sensor 37 is transmitted to the game apparatus 3 as part of the operation data. The game apparatus 3 can calculate the motion and / or posture of the controller 7 based on the data indicating the acceleration, and can appropriately execute processing corresponding to the motion or the like. The controller 7 includes an imaging information calculation unit 35 (described later) for capturing an image viewed from the controller 7. The imaging information calculation unit 35 captures images of the markers 8a and 8b using the markers 8a and 8b arranged around the monitor 2 as imaging targets. The game apparatus 3 can execute processing according to the position and orientation of the controller 7 by arithmetic processing based on this image.

  Next, the configuration of the game apparatus 3 will be described with reference to FIG. FIG. 2 is a functional block diagram of the game apparatus 3.

  In FIG. 2, the game apparatus 3 includes, for example, a risk (RISC) CPU (Central Processing Unit) 10 that executes various programs. The CPU 10 executes a boot program stored in a boot ROM (not shown), initializes a memory such as the main memory 13, and executes a game program stored in the optical disc 4, and according to the game program. Game processing and the like. A GPU (Graphics Processing Unit) 12, a main memory 13, a DSP (Digital Signal Processor) 14, and an ARAM (Audio RAM) 15 are connected to the CPU 10 via a memory controller 11. Further, a controller I / F (interface) 16, a video I / F 17, an external memory I / F 18, an audio I / F 19, and a disk I / F 21 are connected to the memory controller 11 via a predetermined bus. The receiving unit 6, the monitor 2, the external memory card 5, the speaker 22, and the disk drive 20 are connected.

  The GPU 12 performs image processing based on a command from the CPU 10, and is configured of a semiconductor chip that performs calculation processing necessary for displaying 3D graphics, for example. The GPU 12 performs image processing using a memory dedicated to image processing (not shown) and a partial storage area of the main memory 13. The GPU 12 generates game image data and movie video to be displayed on the monitor 2 using these, and outputs them to the monitor 2 through the memory controller 11 and the video I / F 17 as appropriate.

  The main memory 13 is a storage area used by the CPU 10 and appropriately stores game programs and the like necessary for the processing of the CPU 10. For example, the main memory 13 stores a game program read from the optical disc 4 by the CPU 10 and various data. The game program and various data stored in the main memory 13 are executed by the CPU 10.

  The DSP 14 processes sound data generated in the CPU 10 when the game program is executed, and is connected to an ARAM 15 for storing the sound data. The ARAM 15 is used when the DSP 14 performs a predetermined process (for example, storing a pre-read game program or sound data). The DSP 14 reads the sound data stored in the ARAM 15 and outputs the sound data to the speaker 22 provided in the monitor 2 via the memory controller 11 and the audio I / F 19.

  The memory controller 11 comprehensively controls data transfer and is connected to the various I / Fs described above. The controller I / F 16 includes, for example, four controller I / Fs, and connects the external device and the game apparatus 3 that can be fitted to each other via a connector included in the controller I / F so as to communicate with each other. For example, the receiving unit 6 is engaged with the connector and connected to the game apparatus 3 via the controller I / F 16. As described above, the receiving unit 6 receives operation data from the controller 7 and outputs the operation data to the CPU 10 via the controller I / F 16. In another embodiment, the game apparatus 3 may have a configuration in which a reception module that receives operation data transmitted from the controller 7 is provided instead of the reception unit 6. In this case, the operation data received by the receiving module is output to the CPU 10 via a predetermined bus. A monitor 2 is connected to the video I / F 17. The external memory I / F 18 is connected to the external memory card 5 and can access a backup memory or the like provided in the external memory card 5. A speaker 22 built in the monitor 2 is connected to the audio I / F 19, and sound data read by the DSP 14 from the ARAM 15 and sound data directly output from the disk drive 20 are output from the speaker 22. A disk drive 20 is connected to the disk I / F 21. The disk drive 20 reads data stored on the optical disk 4 arranged at a predetermined reading position, and outputs it to the bus of the game apparatus 3 and the audio I / F 19.

  Next, the controller 7 will be described with reference to FIGS. 3 to 4 are perspective views showing the external configuration of the controller 7. 3A is a perspective view of the controller 7 as viewed from the upper rear side, and FIG. 3B is a perspective view of the controller 7 as viewed from the lower rear side. FIG. 4 is a view of the controller 7 as viewed from the front.

  3A to 4, the controller 7 includes a housing 31 formed by plastic molding, for example. The housing 31 has a substantially rectangular parallelepiped shape whose longitudinal direction is the front-rear direction (the z-axis direction shown in FIG. 3), and is a size that can be gripped with one hand of an adult or a child as a whole. By using the controller 7, the player can perform a game operation by pressing a button provided on the controller 7, moving the controller 7 itself, and changing the position and posture of the controller 7 itself. For example, the player can perform an operation on the operation target appearing in the game space by changing the tilt of the controller 7 or moving the controller 7 (for example, shaking the controller 7 in an arbitrary direction). Further, for example, the player can perform an operation on the operation target by an operation of rotating the controller 7 about the longitudinal direction or changing a position on the screen indicated by the controller 7. Here, the “position on the screen indicated by the controller 7” is ideally a position where the straight line extending in the longitudinal direction from the front end of the controller 7 and the screen of the monitor 2 intersect. It is not necessary to be the position, and it is only necessary that the surrounding position can be calculated by the game apparatus 3. Hereinafter, the position on the screen pointed to by the controller 7 is referred to as a “designated position of the controller 7”. Further, the longitudinal direction of the controller 7 (housing 31) may be referred to as “instruction direction of the controller 7”.

  The housing 31 is provided with a plurality of operation keys. On the upper surface of the housing 31, a cross key 32a, an X button 32b, a Y button 32c, an A button 32d, a select switch 32e, a menu switch 32f, and a start switch 32g are provided. On the other hand, a recess is formed in the lower surface of the housing 31, and a B button 32i is provided on the rear inclined surface of the recess. Each of these operation keys (buttons) is assigned a function according to a game program executed by the game apparatus 3, but is not directly related to the description of the present invention, and thus a detailed description thereof is omitted here. In addition, a power switch 32h for turning on / off the power source of the game apparatus 3 from a remote location is provided on the upper surface of the housing 31.

  The controller 7 has an imaging information calculation unit 35 (FIG. 5B). As shown in FIG. 4, a light incident surface 35 a of the imaging information calculation unit 35 is provided on the front surface of the housing 31. On the other hand, a connector 33 is provided on the rear surface of the housing 31. The connector 33 is a 32-pin edge connector, for example, and is used to connect another device to the controller 7. A plurality of LEDs 34 are provided on the rear surface side of the upper surface of the housing 31. Here, a controller type (number) is assigned to the controller 7 in order to distinguish it from other controllers 7. The LED 34 is used to notify the player of the controller type currently set in the controller 7. Specifically, when operating data is transmitted from the controller 7 to the game apparatus 3, any one of the plurality of LEDs 34 is turned on according to the controller type.

  Next, the internal structure of the controller 7 will be described with reference to FIGS. 5A and 5B. 5A and 5B are diagrams showing the internal structure of the controller 7. FIG. 5A is a perspective view showing a state in which the upper housing (a part of the housing 31) of the controller 7 is removed. FIG. 5B is a perspective view showing a state where the lower casing (a part of the housing 31) of the controller 7 is removed. The perspective view shown in FIG. 5B is a perspective view of the substrate 300 shown in FIG.

  5A, a substrate 300 is fixed inside the housing 31, and operation keys 32a to 32h, an acceleration sensor 37, an LED 34, a crystal resonator 46, a wireless module 44, and a wireless module 44 are provided on the upper main surface of the substrate 300. An antenna 45 and the like are provided. These are connected to a microcomputer (microcomputer) 42 (see FIG. 6) by wiring (not shown) formed on the substrate 300 or the like. Further, the controller 7 functions as a wireless controller by the wireless module 44 and the antenna 45. The crystal unit 46 generates a basic clock for the microcomputer 42 described later.

  On the other hand, in FIG. 5B, the imaging information calculation unit 35 is provided at the front edge on the lower main surface of the substrate 300. The imaging information calculation unit 35 includes an infrared filter 38, a lens 39, an imaging device 40 (for example, a CMOS image sensor or a CCD image sensor), and an image processing circuit 41 in order from the front of the controller 7. Attached to the surface. The connector 33 is attached to the rear edge on the lower main surface of the substrate 300. The A button 32i is attached to the lower main surface of the substrate 300 behind the imaging information calculation unit 35, and the battery 47 is accommodated further rearward. A vibrator 48 is attached on the lower main surface of the substrate 300 between the battery 47 and the connector 33. The vibrator 48 may be, for example, a vibration motor or a solenoid. Since the vibration is generated in the controller 7 by the operation of the vibrator 48, the vibration is transmitted to the hand of the player holding the vibrator 48, and a so-called vibration-compatible game can be realized.

  It should be noted that the shape of the controller 7 shown in FIGS. 3A to 5B, the shape of each operation key, the number of acceleration sensors and vibrators, the installation positions, and the like are merely examples, and other shapes, numbers, and installation positions. However, it goes without saying that the present invention can be realized. For example, it can be assumed that the rotation around the Z axis can be easily calculated by shifting the acceleration sensor in either the positive or negative direction of the X axis, and that the entire controller can be easily shaken if the vibrator is arranged on the tip side of the controller. Further, the position of the imaging information calculation unit 35 in the controller 7 (the light incident surface 35a of the imaging information calculation unit 35) does not have to be the front surface of the housing 31, and other surfaces can be used as long as light can be taken in from the outside of the housing 31. May be provided. At this time, the “instruction direction of the controller 7” is a direction perpendicular to the light incident surface, that is, an imaging direction of the imaging element 40.

  FIG. 6 is a block diagram showing the configuration of the controller 7. The controller 7 includes an operation unit 32 (each operation key), an imaging information calculation unit 35, a communication unit 36, and an acceleration sensor 37. In the present embodiment, the controller 7 only needs to include the acceleration detection unit (acceleration sensor 37), and may not include the operation unit 32 and the imaging information calculation unit 35.

  The acceleration sensor 37 detects the acceleration (including gravitational acceleration) of the controller 7, that is, detects the force (including gravity) applied to the controller 7. The acceleration sensor 37 detects the acceleration value in the linear direction along the sensing axis direction among the accelerations applied to the detection unit of the acceleration sensor 37. For example, in the case of a multi-axis acceleration sensor having two or more axes, component acceleration along each axis (linear acceleration) is detected as the acceleration applied to the detection unit of the acceleration sensor. For example, the triaxial or biaxial acceleration sensor 37 may be of the type available from Analog Devices, Inc. or ST Microelectronics NV.

  In the present embodiment, the acceleration sensor 37 has a vertical direction (y-axis direction shown in FIGS. 3A and 3B), a horizontal direction (x-axis direction shown in FIGS. 3A and 3B), and a front-rear direction (see FIG. 3). The linear acceleration is detected in each of the three axis directions (z-axis direction shown in 3A and FIG. 3B). Since the acceleration sensor 37 detects acceleration in the linear direction along each axis, the output from the acceleration sensor 37 represents the linear acceleration value of each of the three axes. That is, the detected acceleration is expressed as a three-dimensional vector in the xyz coordinate system set with the controller 7 as a reference. In the following, a vector that is detected by the acceleration sensor 37 and has respective acceleration values related to a plurality of axes as components is referred to as an acceleration vector.

  7 and 8 are diagrams showing the relationship between the movement of the controller 7 and the output of the acceleration sensor. FIG. 7 shows a state in which the gravitational acceleration (vector VA shown in FIG. 7) is directed downward with the controller 7 as a reference. In FIG. 7, the controller 7 is assumed to be horizontal and stationary. In this state, since gravity (gravity acceleration) is always applied to the controller 7, the acceleration vector VA indicates only gravity acceleration. For example, in the state shown in FIG. 7, the acceleration vector VA is in the negative y-axis direction. That is, 1 G of gravitational acceleration is applied to the acceleration sensor 37 in the negative y-axis direction, and the x-axis and z-axis accelerations are almost zero. In the present embodiment, the magnitude of acceleration detected by the acceleration sensor 37 while the controller 7 is stationary, that is, the acceleration detected when the acceleration detected by the acceleration sensor 37 represents only gravitational acceleration. The size is represented as 1. For example, the value of each component of the acceleration vector VA detected in the state shown in FIG. 7 is (x, y, z) = (0, −1, 0).

  On the other hand, FIG. 8 shows a state when the controller 7 is moved. FIG. 8 shows that the controller 7 moves so that the front end of the controller 7 draws an arc having a larger radius than the rear end in a direction parallel to the xz plane and from the x-axis negative direction side to the positive direction side. It shows the state. The case where the controller 7 moves as shown in FIG. 8 is typically from right to left with the player holding the controller 7 with one hand so that the front surface of the controller 7 faces the front of the player. This is a case where the player swings (moves) the controller 7. In the state shown in FIG. 8, an inertial force due to the movement of the controller 7 is applied to the acceleration sensor 37 in addition to the gravity. Therefore, the acceleration sensor 37 combines the acceleration VA ′ caused by gravity applied to the controller 7 and the acceleration VA ″ (appears as a combined vector of x and y axis components) caused by the inertial force due to the movement of the controller 7. Although the details will be described later, the game apparatus 3 calculates the swing direction of the controller 7 based on the acceleration VA detected in this way. It refers to the moving direction (absolute direction) of the controller 7 with respect to the direction, and is distinguished from the moving direction (relative direction) expressed with reference to the direction of the controller 7.

  The acceleration sensor 37 has a limit in the magnitude of acceleration that can be detected depending on the characteristics of the element. In the present embodiment, the limit value of the range that can be detected by the acceleration sensor 37 for each axis is “± 2.2”. That is, even if the acceleration sensor 37 has a value larger than 2.2 or a value smaller than -2.2, the acceleration sensor 37 has a value of -2.2 to 2.2. Acceleration values are output in the range up to 2.

  Data (acceleration data) indicating the acceleration (acceleration vector) detected by the acceleration sensor 37 is output to the communication unit 36. In the present embodiment, the communication unit 36 of the controller 7 sequentially outputs acceleration data to the game apparatus 3 (for example, once every 0.5 ms). The game apparatus 3 calculates the swing direction of the controller 7 from the acceleration data, and executes a game process corresponding to the swing direction. Since the acceleration sensor 37 detects the acceleration of a linear component along each axis, the game apparatus 3 cannot directly detect the swing direction of the controller 7. For this reason, the swing direction of the device on which the acceleration sensor 37 is mounted is calculated by performing a predetermined calculation process on the acceleration detected for each axis of the acceleration sensor.

  Returning to the description of FIG. 6, the imaging information calculation unit 35 analyzes the image data captured by the imaging unit, discriminates a region having high luminance, and calculates the position of the center of gravity, the size, and the like of the region. It is. Since the imaging information calculation unit 35 has a sampling period of, for example, about 200 frames / second at the maximum, it can track and analyze even a relatively fast movement of the controller 7.

  The imaging information calculation unit 35 includes an infrared filter 38, a lens 39, an imaging element 40, and an image processing circuit 41. The infrared filter 38 allows only infrared light to pass from light incident from the front of the controller 7. Here, the markers 8 a and 8 b arranged in the vicinity of the display screen of the monitor 2 are infrared LEDs that output infrared light toward the front of the monitor 2. Therefore, by providing the infrared filter 38, the images of the markers 8a and 8b can be taken more accurately. The lens 39 collects the infrared light transmitted through the infrared filter 38 and makes it incident on the image sensor 40. The image sensor 40 is a solid-state image sensor such as a CMOS sensor or a CCD, for example, and images the infrared rays collected by the lens 39. Accordingly, the image sensor 40 captures only the infrared light that has passed through the infrared filter 38 and generates image data. Hereinafter, an image captured by the image sensor 40 is referred to as a captured image. Image data generated by the image sensor 40 is processed by the image processing circuit 41. The image processing circuit 41 calculates the position of the imaging target (markers 8a and 8b) in the captured image.

  When a captured image is input, the image processing circuit 41 calculates a coordinate indicating the position of a region that matches a predetermined condition in the captured image for each region. Here, the predetermined condition is a condition for specifying an image to be captured (target image). The specific content of the predetermined condition is that the luminance is a region (high luminance region) having a predetermined value or more, and the size of the region is a size within a predetermined range. The predetermined condition may be a condition for specifying an imaging target, and in other embodiments, may include a condition related to the color of the image.

  When calculating the position of the target image, first, the image processing circuit 41 specifies the high-intensity region as a target image candidate from the region of the captured image. This is because the target image appears as a high luminance area in the image data of the captured image. Next, the image processing circuit 41 performs determination processing for determining whether or not the high luminance area is a target image based on the size of the specified high luminance area. In addition to the images of the two markers 8a and 8b that are target images, the captured image may include images other than the target image due to sunlight from a window or light from a fluorescent lamp in a room. In this case, images other than the images of the markers 8a and 8b also appear as high brightness areas. The above determination process is a process for distinguishing between the images of the markers 8a and 8b, which are target images, and other images, and accurately specifying the target image. Specifically, in the determination process, it is determined whether or not the specified high luminance area has a size within a predetermined range. If the high brightness area is a size within the predetermined range, the high brightness area is determined to represent the target image. If the high brightness area is not a size within the predetermined range, the high brightness area is other than the target image. It is determined that the image is represented.

  Furthermore, as a result of the above determination processing, the image processing circuit 41 calculates the position of the high luminance region for the high luminance region determined to represent the target image. Specifically, the barycentric position of the high brightness area is calculated. Note that the position of the center of gravity can be calculated on a more detailed scale than the resolution of the image sensor 40. For example, even when the resolution of a captured image captured by the image sensor 40 is 126 × 96, the center of gravity position can be calculated on a scale of 1024 × 768. At this time, the coordinates of the barycentric position are expressed by integer values from (0, 0) to (1024, 768).

  As described above, the image processing circuit 41 calculates the coordinates indicating the position of the region that matches the predetermined condition in the captured image for each region. The image processing circuit 41 outputs the calculated coordinates to the microcomputer 42 of the communication unit 36. The coordinate data is transmitted to the game apparatus 3 as operation data by the microcomputer 42. Since these coordinates change corresponding to the orientation (posture) and position of the controller 7 itself, the game apparatus 3 can calculate the orientation and position of the controller 7 using this coordinate value. In the present embodiment, since the coordinate data is not used for the game process, the controller 7 may not include the imaging information calculation unit 35.

  The operation unit 32 corresponds to each operation key 32a to 32i such as the cross key 32a described above, and communicates data indicating an input state (whether or not each operation key 32a to 32i is pressed) to each operation key 32a to 32i. The data is output to the microcomputer 42 of the unit 36.

  The communication unit 36 includes a microcomputer 42, a memory 43, a wireless module 44, and an antenna 45. The microcomputer 42 controls the wireless module 44 that wirelessly transmits data acquired by the microcomputer 42 while using the memory 43 as a storage area during processing.

  Data output from the operation unit 32, the imaging information calculation unit 35, and the acceleration sensor 37 to the microcomputer 42 is temporarily stored in the memory 43. Here, the wireless transmission from the communication unit 36 to the receiving unit 6 is performed every predetermined period, but the game processing is generally performed in units of 1/60 seconds (one frame time). It is preferable to perform transmission at a period equal to or shorter than this time. When the transmission timing to the receiving unit 6 arrives, the microcomputer 42 outputs the data stored in the memory 43 to the wireless module 44 as operation data. The wireless module 44 modulates a carrier wave of a predetermined frequency with operation data using, for example, Bluetooth (registered trademark) technology, and radiates a weak radio signal from the antenna 45. That is, the operation data is modulated by the wireless module 44 into a weak radio signal and transmitted from the controller 7. The weak radio signal is received by the receiving unit 6 on the game apparatus 3 side. By demodulating and decoding the received weak radio signal, the game apparatus 3 can acquire operation data. And CPU10 of the game device 3 performs a game process based on the acquired operation data and a game program.

  By using the controller 7, the player can change the attitude of the controller 7, move the position of the controller 7, or rotate the controller 7 in addition to the conventional general game operation of pressing each operation key. It is possible to perform game operations such as

  FIG. 9 is an illustrative view outlining a state when a game operation is performed using the controller 7. When playing a game using the controller 7 in the game system 1, the player holds the controller 7 with one hand as shown in FIG. In the present embodiment, the player performs a game operation by swinging (moving) the gripped controller 7 in an arbitrary direction.

  Hereinafter, a specific example of a game performed using the above-described game system 1 will be described. 10 and 11 are diagrams illustrating an example of the game screen displayed on the monitor 2 in the present embodiment. As shown in FIGS. 10 and 11, a virtual three-dimensional game space is displayed on the monitor 2. An object 51 imitating a log (hereinafter referred to as a log object 51) and an object 52 imitating a sword (hereinafter referred to as a sword object 52) are arranged in the game space. The player operates the sword object 52 using the controller 7 and plays by cutting the log object 51 with the sword object 52 (see FIG. 11).

  The operation of the sword object 52 is performed by an operation of swinging the controller 7 in an arbitrary direction. That is, the player performs an operation (shake operation) of swinging the controller 7 in an arbitrary direction in order to operate the sword object 52. In this game, the player holds the controller 7 so that the longitudinal direction of the controller 7 is substantially perpendicular to the swing direction of the controller 7. Further, regarding how to hold the controller 7, the player may hold the controller 7 so that the upper surface of the controller 7 is oriented in any direction, up, down, left and right. That is, the controller 7 is held in an arbitrary posture with respect to the rotation direction around the z axis.

  When the player performs the above swing operation using the controller 7, the game apparatus 3 first calculates the swing direction of the controller 7. In the present embodiment, the game apparatus 3 calculates the swing direction with respect to the gravity direction with respect to the x axis and the y axis in the xyz coordinate system (see FIG. 3) with the controller 7 as a reference. Although details will be described later, in this embodiment, it is possible to calculate the moving direction (swing direction) of the controller 7 with respect to the gravitational direction, regardless of the orientation of the controller 7 with respect to the rotation direction around the z-axis. It is. In another embodiment, the swing direction with respect to the gravity direction may be calculated with respect to the three axes of the x axis, the y axis, and the z axis.

  When the swing direction is calculated, the game apparatus 3 moves the sword object 52 in the screen in a direction corresponding to the swing direction. For example, when the player swings the controller 7 from left to right, the sword object 52 moves from left to right on the screen (see FIG. 11). When the player swings the controller 7 from the bottom to the top, the sword object 52 moves from the bottom to the top of the screen.

  When the sword object 52 is moved, the game apparatus 3 determines whether or not the sword object 52 has come into contact with the log object 51. When the sword object 52 comes into contact with the log object 51, the log object 51 is cut and displayed along the trajectory of the sword object 52 as shown in FIG. Thus, since the sword object 52 moves according to the swing direction of the controller 7, the player can obtain an operation feeling as if the sword object 52 is swung by swinging the controller 7 in a desired direction. Can do. In addition, an unprecedented game operation is possible in which a game operation is performed by shaking the controller 7.

  Next, program processing executed by the game apparatus 3 in the present embodiment will be described. First, main data used in the game process will be described with reference to FIG. FIG. 12 is a diagram showing main data stored in the main memory 13 of the game apparatus 3. As shown in FIG. 12, the main memory 13 stores a game program 61, operation data 62, game processing data 63, and the like. In addition to the data shown in FIG. 12, the main memory 13 stores data necessary for game processing, such as image data of objects appearing in the game.

  A part or all of the game program 61 is read from the optical disc 4 and stored in the main memory 13 at an appropriate timing after the game apparatus 3 is turned on. The game program 61 includes a program necessary for executing a game process described later.

  The operation data 62 is transmitted from the controller 7 to the game apparatus 3 and stored in the main memory 13. The operation data 62 includes acceleration data 621. In the present embodiment, the acceleration data 621 indicates acceleration values related to the three axes, the x axis, the y axis, and the z axis. In addition to the acceleration data 621, the operation data 62 includes data indicating the position of the imaging target (markers 8 a and 8 b) in the captured image, and data indicating the operation performed on each button of the operation unit 32. May be included.

  The game processing data 63 is data used in game processing described later. The game processing data 63 includes a selected acceleration data group 631, auxiliary line data 632, first to fourth control point data 633 to 636, first to third direction vector data 637 to 639, a difference vector data group 640, a moving direction. Data 641, gravity direction data 642, swing direction data 643, and operation flag data 644 are included.

  The selected acceleration data group 631 is a set of acceleration data selected according to a predetermined reference from the acceleration data sequentially acquired from the controller 7. The predetermined standard is that the acceleration data sequentially acquired from the controller 7 is acquired within the movement period. The movement period is a period during which it is determined that the controller 7 is moving. Specifically, the movement period is a period from a time point when it is determined that the controller 7 starts to move (start time point) to a time point when the movement of the controller 7 is determined to end (end time point). Although details will be described later, the detection of the movement period is performed using the acceleration in the z-axis direction detected by the acceleration sensor 37. The selected acceleration data group 631 may include only one acceleration data.

FIG. 13 is a diagram illustrating an example of the selected acceleration data group 631. In FIG. 13, one block indicates one acceleration data, and the blocks are arranged from the top in the order in which the acceleration data is acquired. Hereinafter, among the acceleration data included in the selected acceleration data group 631, the acceleration vector indicated by the i-th (i is an integer of 1 or more) acquired acceleration data is indicated as “VA _i ”.

  As shown in FIG. 13, each acceleration data stored in the main memory 13 as the selected acceleration data group 631 indicates a two-dimensional acceleration vector having acceleration components related to the x-axis and the y-axis in the xyz coordinate system as components. . That is, when the acceleration data acquired from the controller 7 is stored in the main memory 13 as the selected acceleration data group 631, the acceleration value related to the z axis among the acceleration values related to the three axes indicated by the acceleration data is not stored. Data indicating only acceleration values relating to the remaining x-axis and y-axis is stored. The reason why the acceleration data included in the selected acceleration data group 631 is data indicating a two-dimensional acceleration vector is to calculate the swing direction with respect to the x-axis and the y-axis in the present embodiment. This is because the acceleration value relating to the z-axis is not used in the calculation process. That is, in the present embodiment, the game apparatus 3 calculates the swing direction of the controller 7 using the two-dimensional acceleration vector.

Further, the acceleration sensor 37 has a limit in the detectable acceleration value, and a limit value is output for an acceleration exceeding the limit. Therefore, the selected acceleration data group 631 includes acceleration data in which any one of the components of the acceleration vector indicated by the acceleration data takes a limit value (= ± 2.2) of a range that can be detected by the acceleration sensor 37. May be included. Hereinafter, such acceleration data is referred to as “limit acceleration data”. Further, the acceleration data that is not the limit acceleration data in the selected acceleration data group 631 is referred to as “non-limit acceleration data”. In FIG. 13, between the third acceleration vector VA ₃ and the fifth acceleration vector VA ₅ , the value of the x component of the acceleration vector is “−2.2” which is a limit value. Therefore, the third to fifth acceleration data are the limit acceleration data group 631 ′. The acceleration value of the limit acceleration data group 631 ′ is corrected by a data correction process (step S22) described later. Although details will be described later, in the data correction process, a component that takes the limit value among the components of the two-dimensional acceleration vector indicated by the limit acceleration data is corrected.

Returning to the description of FIG. 12, the auxiliary line data 632 is data indicating an auxiliary line used for correcting the limit acceleration data group 631 ′. In the present embodiment, a cubic Bezier curve is used as the auxiliary line. A Bezier curve is defined by the following relational expression (1) between a variable p and a variable u.
p = P0 × (1-u) ³ + P1 × 3u (1-u) ² + P2 × 3u ² (1-u) + P3u ³ (1)
In the above equation (1), the variable p is a coordinate value in the xy coordinate system composed of the x-axis and the y-axis, like the two-dimensional acceleration vector. The variable u is a scalar value that takes a value in the range of 0 ≦ u ≦ 1. Constants P0, P1, P2, and P3 are control points. By determining the values of these four control points, the shape of the Bezier curve is determined.

  The first to fourth control point data 633 to 636 are data indicating the values of the four control points of the Bezier curve. That is, the first control point data 633 indicates the control point P0, the second control point data 634 indicates the control point P1, the third control point data 635 indicates the control point P2, and the fourth control point data 636. Indicates the control point P3. The first to fourth control points P0 to P3 are expressed by coordinate values in the xy coordinate system including the x axis and the y axis.

  The first to third direction vector data 637 to 639 indicate three vectors used for determining the four control points P0 to P3. That is, the first direction vector data 637 indicates the first direction vector V1, the second direction vector data 638 indicates the second direction vector V2, and the third direction vector data 639 indicates the third direction vector V3. The first to third direction vectors are expressed in the xy coordinate system, similarly to the two-dimensional acceleration vector. A method for calculating the first to third direction vectors will be described later.

  The difference vector data group 640 indicates a set of difference vector data calculated from each acceleration data included in the selected acceleration data group 631. The difference vector data indicates a vector of a difference between the acceleration vector indicated by the acceleration data and the acceleration vector indicated by the acceleration data acquired next, for each acceleration data included in the selected acceleration data group 631. The difference vector data group 640 is used to calculate a moving direction vector to be described later.

  The movement direction data 641 indicates the movement direction of the controller 7 expressed with reference to the direction of the controller 7. This moving direction is expressed by a vector in the xy coordinate system. Hereinafter, a vector representing this movement direction is referred to as a movement direction vector. The moving direction vector is calculated using the difference vector data group 640.

  The gravity direction data 642 indicates the direction of gravity applied to the controller 7 expressed with reference to the direction of the controller 7. The direction of gravity is expressed by a vector in the xy coordinate system. Hereinafter, a vector representing the gravity direction is referred to as a gravity direction vector. The gravity direction vector is calculated using the selected acceleration data group 631.

  The swing direction data 643 indicates a direction (swing direction) in which the controller 7 is swung with respect to the gravity direction. The swing direction is represented by a vector in an XY coordinate system (see FIG. 21) for representing a direction based on the direction of gravity. Hereinafter, a vector representing the swing direction is referred to as a swing direction vector. The swing direction vector is calculated using the movement direction vector and the gravity direction vector. In the present embodiment, the game process is executed directly based on this swing direction vector. That is, the game apparatus 3 moves the sword object 52 in the game space in a direction corresponding to the direction of the swing direction vector.

  The operation flag data 644 is operation flag data indicating whether or not a swing operation is being performed by the player. The operation flag is set to on when the swing operation is performed, and is set to off when the swing operation is not performed.

  Next, details of processing performed in the game apparatus 3 will be described with reference to FIGS. FIG. 14 is a main flowchart showing the flow of processing executed in the game apparatus 3. When the power of the game apparatus 3 is turned on, the CPU 10 of the game apparatus 3 executes a startup program stored in a boot ROM (not shown), whereby each unit such as the main memory 13 is initialized. Then, the game program stored in the optical disc 4 is read into the main memory 13 and the CPU 10 starts executing the game program. The flowchart shown in FIG. 14 is a flowchart showing processing performed after the above processing is completed.

  First, in step S1, data initialization processing used in the subsequent processing is executed. That is, the CPU 10 clears the contents of the data 631 to 643 included in the game processing data 63 in the main memory 13. Further, the content of the operation flag data 644 is set to data indicating OFF. At this time, the log object 51 is arranged in the virtual three-dimensional space. After execution of step S1, the game progresses by repeating the processing loop of steps S2 to S11.

  In step S <b> 2, the CPU 10 acquires operation data from the controller 7. That is, since the controller 7 transmits operation data to the game apparatus 3 at a predetermined time interval (for example, within one frame time interval), the CPU 10 stores the transmitted operation data in the main memory 13. This operation data includes at least the acceleration data. The CPU 10 stores acceleration data in the main memory 13. When acceleration data 621 is already stored in the main memory 13, the contents of the acceleration data 621 are updated and stored so as to be the contents of the acquired acceleration data. In the present embodiment, since the process of step S2 is executed every frame time except during the processes of steps S8 to S10, the game apparatus 3 can sequentially acquire acceleration data.

  In subsequent step S3, the CPU 10 determines whether or not the operation of shaking the controller 7 is being performed by the player. The determination in step S3 is performed by referring to the operation flag data 644 stored in the main memory 13. That is, when the operation flag is set on, it is determined that the operation of shaking the controller 7 is being performed. When the operation flag is set off, the operation of shaking the controller 7 is performed. It is judged that it is not. If the determination result of step S3 is negative, the process of step S4 is executed. On the other hand, when the determination result of step S3 is affirmative, the process of step S7 described later is executed.

  In step S4, the CPU 10 determines whether or not a swing operation has been started. The determination in step S4 is made based on the acceleration data 621 stored in the main memory 13. That is, when the acceleration value related to the z-axis indicated by the acceleration data 621 is greater than a predetermined first threshold value, it is determined that the swing operation has started, and the acceleration value related to the z-axis is equal to or less than the first threshold value. It is determined that the swing operation has not been started.

  Here, while the swinging operation is performed, as shown in FIG. 8, a centrifugal force is applied to the controller 7 in the z-axis direction. Therefore, when the swing operation is performed at a certain speed, the acceleration value related to the z-axis becomes larger than the first threshold value. Therefore, as shown in step S4, the swing operation is performed by referring to the acceleration value related to the z-axis and determining whether the acceleration value is larger than a predetermined value (first threshold value). It can be easily determined whether or not there is.

  If the determination result of step S4 is affirmative, the processes of steps S5 and S6 are executed. On the other hand, if the determination result of step S4 is negative, the processes of steps S5 and S6 are skipped and the process of step S11 described later is executed.

  In step S5, the operation flag is set to ON. That is, the CPU 10 rewrites the contents of the operation flag data 644 stored in the main memory 13 to data indicating ON. Thereby, when the loop process of steps S2 to S11 is performed next, the determination result of step S3 becomes affirmative.

  In subsequent step S <b> 6, the CPU 10 stores the acceleration data acquired in step S <b> 2 as a selected acceleration data group 631. That is, the acceleration data 621 stored in the main memory 13 is added to the acceleration data included in the selected acceleration data group 631. As described above, in the present embodiment, the acceleration value related to the z-axis among the acceleration values related to the three axes indicated by the acceleration data 621 is not stored, and only the acceleration values related to the remaining x-axis and y-axis are shown. Data is stored. That is, as shown in FIG. 13, data indicating a two-dimensional acceleration vector is stored. After step S6, the process of step S11 described later is executed.

  On the other hand, in step S7, the CPU 10 determines whether or not the swing operation has been completed. The determination in step S7 is made based on the acceleration data 621 stored in the main memory 13. That is, when the acceleration value related to the z-axis indicated by the acceleration data is equal to or smaller than a predetermined second threshold value, it is determined that the swing operation has ended, and when the acceleration value related to the z-axis is larger than the second threshold value, It is determined that the swing operation has not ended. Note that while the swing operation is not performed, as shown in FIG. 7, the centrifugal force is not applied to the controller 7 in the z-axis direction, so the acceleration value related to the z-axis is equal to or less than the second threshold value. Therefore, referring to the acceleration value related to the z-axis as described above, it is determined whether or not a swing operation is performed by determining whether or not the acceleration value is equal to or less than a predetermined value (second threshold value). It can be easily determined. The first threshold value and the second threshold value may be the same value or different values. In the present embodiment, for example, both the first threshold value and the second threshold value are set to “1.1”. If the determination result of step S7 is affirmative, the processes of steps S8 to S10 described later are executed. On the other hand, when the determination result of step S7 is negative, the process of step S6 described above is executed.

  FIG. 15 is a diagram showing the transition of the acceleration data acquired in step S2 during a certain period. FIG. 15 represents the acceleration vector indicated by the acquired acceleration data as coordinates in a two-dimensional coordinate system composed of x and y coordinates. Each point p1 to p19 in FIG. 15 indicates the position of the end of each acceleration vector, and the position of the start of each acceleration vector is the origin. For example, the acceleration vector indicated by the point p1 is a vector having the origin as the starting point and the position of the point p1 as the ending point. FIG. 15 shows 19 acceleration vectors from point p1 to point p2, point p3,..., Point p19 in the order of acquisition. In FIG. 15, dots indicated by white circles indicate acceleration vectors when the acceleration value related to the z-axis indicated by the acceleration data corresponding to the acceleration vector is equal to or less than the first threshold value (second threshold value). Further, in FIG. 15, a point indicated by a black circle indicates an acceleration vector when the acceleration value related to the z-axis indicated by the acceleration data corresponding to the acceleration vector is larger than the first threshold value (second threshold value).

  When the swing operation is not started immediately after the start of the game (including when the controller 7 is not swinging at a sufficient speed), the acceleration value related to the z axis as indicated by the white circle points p1 and p2 is Acceleration data that is less than or equal to the first threshold is acquired in step S2. At this time, since the determination results in steps S3 and S4 are both negative, the acceleration data is not stored. Then, when the controller 7 is shaken at a certain speed after the swing operation is started, acceleration data having an acceleration value related to the z-axis larger than the first threshold value as shown by a black dot p3 is acquired in step S2. . At this time, the determination result of step S3 is negative and the determination result of step S4 is affirmative. As a result, the game apparatus 3 detects the time when the swing operation is started, that is, the start time of the moving period. Then, the storage of the acceleration data is started from the time when the swing operation is started (step S6). In the example of FIG. 15, the acceleration vector corresponding to the point p <b> 3 is stored in the main memory 13.

  While the swinging operation continues, acceleration data whose acceleration value related to the z-axis is larger than the first threshold value is acquired in step S2, as indicated by black circle points p4 to p17. At this time, since the determination result of step S3 is affirmative and the determination result of step S7 is negative, acceleration data storage (step S6) is continuously performed. Therefore, following the point p3, acceleration vectors corresponding to the points p4 to p17 are sequentially stored in the main memory 13.

  When the speed of the controller 7 decreases and the swing operation is finished, acceleration data in which the acceleration value related to the z-axis is equal to or less than the first threshold value as shown by a white circle point p18 is acquired in step S2. At this time, the determination result of step S3 is affirmative and the determination result of step S7 is affirmative. As a result, the game apparatus 3 detects the time point when the swing operation is ended, that is, the time point when the moving period ends. Then, when the swing operation is finished, the storage of the acceleration data is finished, and the processes of steps S8 to S10 are executed. As described above, the acceleration vector data indicated by the acceleration data acquired during the movement period is stored in the main memory 13 as the selected acceleration data group 631. In the example of FIG. 15, acceleration vector data corresponding to the points p <b> 3 to p <b> 17 is stored in the main memory 13.

  The processes in steps S8 to S10 are executed immediately after the swing operation is completed. In the processes of steps S8 to S10, the swing direction of the controller 7 by the swing operation is calculated (step S8), and the game process (step S9) based on the calculated swing direction is executed. Hereinafter, details of the processing in steps S8 to S10 will be described.

  First, in step S8, a swing direction calculation process is executed. The swing direction calculation process is a process for calculating the swing direction of the controller 7 by the swing operation performed immediately before. Hereinafter, details of the swing direction calculation processing will be described with reference to FIG.

  FIG. 16 is a flowchart showing details of the swing direction calculation process (step S8) shown in FIG. In the swing direction calculation process, first, in step S21, the CPU 10 selects limit acceleration data from the selected acceleration data group 631. As described above, the limit acceleration data is acceleration data in which any one of the components of the acceleration vector takes a limit value in a range that can be detected by the acceleration sensor 37. In the example of FIG. 15, point p5, point p6, point p7, point p13, point p14, and point p15 correspond to the limit acceleration data. Note that a region A surrounded by a dotted line shown in FIG. 15 indicates a range in which acceleration data can be detected (−2.2 ≦ x ≦ 2.2, −2.2 ≦ y ≦ 2.2).

  In step S21, a set of a plurality of limit acceleration data acquired continuously is selected as one limit acceleration data group 631 '. Therefore, in the selected acceleration data group 631, when there are two sets of continuously acquired limit acceleration data, the two limit acceleration data groups 631 'are handled as different sets. In the example of FIG. 15, a set of limit acceleration data corresponding to the points p5, p6, and p7 is selected as one limit acceleration data group 631 ′, and also corresponds to the points p13, p14, and p15. A set of limit acceleration data is selected as another limit acceleration data group 631 ′.

  In step S22, data correction processing is executed. The data correction process is a process for correcting the value of each limit acceleration data included in the limit acceleration data group 631 '. The details of the data correction process will be described below with reference to FIG.

  FIG. 17 is a flowchart showing details of the data correction process (step S22) shown in FIG. In the data correction process, first, in step S31, the CPU 10 selects one of the limit acceleration data groups 631 'stored in the main memory 13. This is because, as described above, a plurality of limit acceleration data groups 631 'may be selected in step S21. In the processing of steps S32 to S40 shown below, correction is performed for the limit acceleration data group 631 'selected in step S31.

上式（２）において、ベクトルＶＡ_t は、選出加速度データ群に含まれる第ｔ番目の加速度ベクトルを示す。また、変数ｋは、選出加速度データ群６３１に含まれる加速度ベクトルの数を示す。上式（２）から明らかなように、第３方向ベクトルＶ３は、（ａ）選出加速度データ群６３１に含まれる各加速度データについて、加速度データに対応する加速度ベクトル（ＶＡ_t ）と当該加速度データの次に取得された加速度データに対応する加速度ベクトル（ＶＡ_t+1 ）との差分ベクトル（ＶＡ_t+1 −ＶＡ_t ）をそれぞれ算出し、（ｂ）各差分ベクトルに対して差分ベクトルの大きさ（｜ＶＡ_t+1 −ＶＡ_t ｜）に応じた重み付けを行って当該各差分ベクトルの総和を算出することによって算出される。 In subsequent step S32, CPU 10 calculates a third direction vector for determining a control point of the auxiliary line. The third direction vector is a vector V3 shown in FIG. 15, for example, and is calculated based on the selected acceleration data group 631 stored in the main memory 13. Specifically, the third direction vector V3 is calculated according to the following equation (2).

In the above equation (2), the vector VA _t represents the t-th acceleration vector included in the selected acceleration data group. The variable k indicates the number of acceleration vectors included in the selected acceleration data group 631. As apparent from the above equation (2), the third direction vector V3 is obtained by (a) for each acceleration data included in the selected acceleration data group 631, the acceleration vector (VA _t ) corresponding to the acceleration data and the acceleration data Next, a difference vector (VA _{t + 1} −VA _t ) from the acceleration vector (VA _{t + 1} ) corresponding to the acquired acceleration data is calculated, and (b) the size of the difference vector for each difference vector. It is calculated by performing weighting according to (| VA _{t + 1} −VA _t |) and calculating the sum of the difference vectors.

  Data indicating the third direction vector V3 calculated as described above is stored in the main memory 13 as third direction vector data 639. In the above formula (2), the third direction vector V3 is calculated using all the acceleration data included in the selected acceleration data group 631, but in other embodiments, the third direction vector V3 is selected from the selected acceleration data group 631. The third direction vector may be calculated using only the non-limit acceleration data.

  In subsequent step S33, CPU 10 determines whether or not it is necessary to correct the direction of the third direction vector. The determination in step S33 is made based on the third direction vector, the immediately preceding acceleration vector, and the immediately following acceleration vector. Here, the immediately preceding acceleration vector is an acceleration vector indicated by acceleration data acquired immediately before limit acceleration data (limit acceleration data group selected in step S21) among non-limit acceleration data. The immediate acceleration vector is an acceleration vector indicated by acceleration data acquired immediately after limit acceleration data (limit acceleration data group selected in step S21) among non-limit acceleration data. For example, in the example of FIG. 15, when the limit acceleration data group indicated by the points p5 to p7 is selected, the acceleration data corresponding to the point p4 acquired immediately before the point p5 is the immediately preceding acceleration data. The acceleration data corresponding to the point p8 acquired immediately after the point p7 is the immediately following acceleration data.

  Specifically, the determination in step S33 is performed by calculating the inner product of a vector obtained by adding the immediately preceding acceleration vector and the immediately following acceleration vector and the third direction vector. That is, when the inner product value becomes negative, it is determined that the direction of the third direction vector needs to be corrected. When the inner product value does not become negative, it is determined that the direction of the third direction vector does not need to be corrected. . If the determination result of step S33 is affirmative, the process of step S34 is executed. On the other hand, when the determination result of step S33 is negative, the process of step S34 is skipped and the process of step S35 is executed.

  In step S34, the third direction vector calculated in step S32 is corrected. Specifically, the CPU 10 corrects the third direction vector so that the direction of the third direction vector is reversed. At this time, the content of the third direction vector data 639 stored in the main memory 13 is rewritten to data indicating the content after correction. After step S34, the process of step S35 is executed.

In step S35, the CPU 10 calculates a first direction vector V1 for determining the control point of the auxiliary line. In the present embodiment, the first direction vector is calculated based on the immediately preceding acceleration data and the non-limit acceleration data acquired immediately before the immediately preceding acceleration data. These acceleration data are included in the selected acceleration data group 631 stored in the main memory 13. Specifically, the first direction vector V1 is calculated according to the following equation (3).
V1 = VA _N −VA _N−1 (3)
In the above equation (3), the vector VA _N is an acceleration vector indicated by the immediately preceding acceleration data, and the vector VA _N-1 is an acceleration vector indicated by the non-limit acceleration data acquired immediately before the immediately preceding acceleration data. . As in the above equation (3), the first direction vector is a vector obtained by subtracting the acceleration vector indicated by the non-limit acceleration data acquired immediately before the previous acceleration data from the acceleration vector indicated by the immediately preceding acceleration data. Is calculated as Accordingly, in the example of FIG. 15, the first direction vector V1 is a vector having the point p3 as a start point and the point p4 as an end point. Data indicating the first direction vector calculated as described above is stored in the main memory 13 as first direction vector data 637.

  In other embodiments, the first direction vector V1 may be calculated based on the immediately preceding acceleration data and one or more acceleration data acquired before the immediately preceding acceleration data. For example, the first direction vector V1 may be calculated based on the immediately preceding acceleration data and acceleration data acquired one and two times before the immediately preceding acceleration data. At this time, the CPU 10 calculates an approximate line regarding the end points of the three acceleration vectors corresponding to the three acceleration data, and sets a vector indicating the inclination of the approximate line as the first direction vector.

In step S36, the CPU 10 calculates a second direction vector V2 for determining the control point of the auxiliary line. In the present embodiment, the second direction vector is calculated based on the immediately-right acceleration data and the non-limit acceleration data acquired immediately after the immediately-right acceleration data. These acceleration data are included in the selected acceleration data group 631 stored in the main memory 13. Specifically, the second direction vector V2 is calculated according to the following equation (4).
V2 = VA _Q −VA _{Q + 1} (4)
In the above equation (4), the vector VA _Q is an acceleration vector indicated by the immediate acceleration data, and the vector VA _{Q + 1} is an acceleration vector indicated by non-limit acceleration data acquired immediately after the immediately following acceleration data. As in the above equation (4), the second direction vector is a vector obtained by subtracting the acceleration vector indicated by the non-limit acceleration data acquired immediately after the immediate acceleration data from the acceleration vector indicated by the immediate acceleration data. Calculated. Therefore, in the example of FIG. 15, the second direction vector V2 is a vector having the point p9 as the start point and the point p8 as the end point. Data indicating the second direction vector calculated as described above is stored in the main memory 13 as second direction vector data 638. In other embodiments, the second direction vector V2 may be calculated based on the immediate acceleration data and one or more acceleration data acquired after the immediate acceleration data, like the first direction vector. Good.

  In step S <b> 37, the CPU 10 calculates the protrusion amount n for determining the control point of the auxiliary line. The protrusion amount n is calculated based on the limit acceleration data group 631 ′ included in the selected acceleration data group 631 stored in the main memory 13. Specifically, the protrusion amount n is set to the number of limit acceleration data included in the limit acceleration data group 631 'selected in step S31. Although the details will be described later, the protruding amount n affects the shape of the auxiliary line. Specifically, the greater the value of the protrusion amount n, the greater the degree that the auxiliary line protrudes.

  In subsequent step S38, the CPU 10 determines each control point P0 to P3 of the auxiliary line. FIG. 18 is a diagram illustrating an example of each control point and auxiliary line to be determined. In FIG. 18, the area | region where the point p3-point p9 shown in FIG. 15 is contained among the area | regions of xy coordinate system is shown in particular. As shown in FIG. 18, the first control point P0, which is one of the four control points of the Bezier curve, is determined at the position of the point p4 representing the acceleration vector indicated by the immediately preceding acceleration data. Data indicating the determined first control point P 0 is stored in the main memory 13 as first control point data 633. The fourth control point P3, which is the other end point, is determined at the position of the point p8 representing the acceleration vector indicated by the immediately following acceleration. Data indicating the determined fourth control point P3 is stored in the main memory 13 as fourth control point data 636.

The second control point P1, which is one of the four control points of the Bezier curve, is based on the first direction vector V1, the third direction vector V3, the protrusion amount n, and the first control point P0. It is determined. Specifically, the CPU 10 calculates the position of the second control point P1 according to the following equation (5).
P1 = P0 + (V1 + V3 × K0) × n × K1 (5)
In the above equation (5), the constant K0 and the constant K1 are scalar values that are predetermined as appropriate values. Data indicating the calculated second control point P 1 is stored in the main memory 13 as second control point data 634. As shown in FIG. 18, the second control point P1 is a position obtained by moving the position of the first control point P0 by the length of the vector V4 in the direction of the vector V4 in FIG. The vector V4 is a vector having the first direction vector V1 and the third direction vector V3 as components and having a length corresponding to the protrusion amount n.

The third control point P2, which is the other direction point among the four control points of the Bezier curve, is based on the second direction vector V2, the third direction vector V3, the protrusion amount n, and the fourth control point P3. It is determined. Specifically, the CPU 10 calculates the position of the third control point P2 according to the following equation (6).
P2 = P3 + (V2 + V3 × K0) × n × K1 (6)
Data indicating the third control point P2 calculated by the above equation (6) is stored in the main memory 13 as third control point data 635. As shown in FIG. 18, the third control point P2 is a position obtained by moving the position of the fourth control point P3 by the length of the vector V5 in the direction of the vector V5 in FIG. The vector V5 is a vector having the second direction vector V2 and the third direction vector V3 as components and having a length corresponding to the protrusion amount n. As described above, the control points P0 to P3 for determining the Bezier curve as the auxiliary line are determined.

  In other embodiments, the vector V4 shown in FIG. 18 may be calculated based on only one of the first direction vector V1 and the third direction vector V3. Further, the vector V5 shown in FIG. 18 may be calculated based on only one of the second direction vector V2 and the third direction vector V3.

  In subsequent step S <b> 39, the CPU 10 determines an auxiliary line based on the control point data 633 to 636 stored in the main memory 13. Specifically, a function representing a Bezier curve as an auxiliary line is determined by substituting the values of the control points P0 to P3 into the above equation (1). Data indicating the determined function is stored in the main memory 13 as auxiliary line data 632.

  In the example shown in FIG. 18, the auxiliary line determined by the control points P0 to P3 is a curve L. Specifically, the inclination of the auxiliary line L at the control point P0 is the inclination of the line segment connecting the control point P0 and the control point P1, and the inclination of the auxiliary line L at the control point P3 is the control point P3 and the control point P2. The slope of the line segment connecting Further, the longer the distance from the control point P0 to the control point P1, the longer the length of the auxiliary line L. From the point B on the auxiliary line L farthest from the region A indicating the range that the acceleration sensor 37 can detect. The distance to the area A increases. Similarly, the longer the distance from the control point P3 to the control point P2, the longer the length of the auxiliary line L and the greater the distance from the point B to the region A.

  In subsequent step S <b> 40, the CPU 10 corrects the value of the limit acceleration data group 631 ′ based on the auxiliary line data 632 stored in the main memory 13. The value of the limit acceleration data is corrected so as to be a value on the auxiliary line. That is, the CPU 10 corrects the xy coordinate value of the acceleration vector indicated by the limit acceleration data so as to be the coordinate value on the auxiliary line. In the present embodiment, the corrected coordinate value of each limit acceleration data is determined so that the auxiliary line is equally divided by each coordinate position corresponding to each limit acceleration data. Referring to FIG. 18 as an example, corrected points p5 'to p7' of points p5 to p7 corresponding to the limit acceleration data are determined to be positions at which the auxiliary line L is equally divided by each point. Specifically, in the above equation (1), the position indicated by the variable p when the variable u = 0.25 is set as the position of the point p5 ′, and is indicated by the variable p when the variable u = 0.5. The position indicated by the variable p when the variable u = 0.75 in the above equation (1) is the position of the point p7 ′. The corrected coordinates only need to be set on the auxiliary line L, and the auxiliary line L is a curve that connects the control point P0 in the area A to the control point P3 in the area A through the outside of the area A. Therefore, the corrected points p5 ′ to p7 ′ can be positions in the region A. In step S40, the contents of the limit acceleration data group 631 'stored in the main memory 13 are rewritten with the corrected contents.

  In addition, according to the correction method shown in FIG. 18, each coordinate value after correction | amendment of each limit acceleration data can be arrange | positioned with sufficient balance on an auxiliary line. The correction method shown in FIG. 18 is effective when it can be assumed that the actual acceleration interval while the acceleration data takes the limit value is almost constant. The method for correcting the limit acceleration data performed according to the auxiliary line is not limited to the above correction method, and any method can be used as long as the xy coordinate value of the limit acceleration data is corrected to the coordinate value on the auxiliary line. It may be. FIG. 19 is a diagram illustrating another example of the method of correcting the limit acceleration data. In the method shown in FIG. 19, only the x coordinate value of the limit acceleration data is corrected, and the y coordinate value is not corrected. As described above, in other embodiments, the acceleration value may be corrected only for the component (the x component in FIG. 19) that takes the limit value among the components of the limit acceleration data. The method shown in FIG. 19 is effective when it can be assumed that acceleration values of components other than the component taking the limit value are reliable.

  In step S41, the CPU 10 determines whether or not all the limit acceleration data have been corrected. If the limit acceleration data not selected in step S31 remains, it is determined that there is limit acceleration data that has not been corrected, and the process of step S31 is executed again for the limit acceleration data that has not been corrected. On the other hand, when all the limit acceleration data are selected in step S31, it is determined that all the limit acceleration data have been corrected, and the CPU 10 ends the data correction process shown in FIG.

  In the data correction process described above, the auxiliary line L is calculated, and the value of the acceleration data is corrected so that the xy coordinates indicated by the acceleration data are positioned on the auxiliary line L. That is, the transition of acceleration during the period in which the actual value could not be detected because the limit value range was exceeded is estimated by the auxiliary line L. Thereby, it is possible to know the transition of acceleration in the entire movement period more accurately, and to correct the value of the selected acceleration data group 631 to be more accurate.

  In the above embodiment, the slope (vector V4 shown in FIG. 18) of the auxiliary line (Bézier curve) L at the first control point P0 is calculated based on the first direction vector V1 and the third direction vector V3. (Refer to the above formula (5)). The inclination (vector V5 shown in FIG. 18) of the auxiliary line (Bézier curve) L at the fourth control point P3 is calculated based on the second direction vector V2 and the third direction vector V3 (see the above equation (6)). . Here, as can be seen from step S35, the first direction vector V1 indicates the transition of the value of the acceleration data immediately before the acceleration data takes the limit value. The second direction vector V2 indicates the transition of the acceleration data value immediately after the acceleration data takes the limit value. Therefore, by determining the inclination at the end point of the auxiliary line L reflecting the first and second direction vectors V1 and V2, a curve indicating the transition of the acceleration data value before and after taking the limit value, the auxiliary line L, Can be connected smoothly (so that the change in inclination is continuous). As a result, it is possible to accurately estimate the transition of the acceleration during the period in which the actual value could not be detected because the limit value range was exceeded so as to be closer to the actual transition.

  Further, as shown in FIG. 15, the third direction vector V3 indicates the transition of acceleration over the entire movement period. Therefore, by determining the inclination at the end point of the auxiliary line L reflecting the third direction vector V3, the inclination can be determined so as to reflect the overall trend of acceleration during the movement period. As a result, it is possible to accurately estimate the transition of the acceleration during a period in which the actual value could not be detected because the limit value range was exceeded so as to be closer to the actual value. For example, in the method of determining the inclination of the auxiliary line L based only on the first and second direction vectors V1 and V2, the value of the immediately preceding acceleration data or the immediately following acceleration data is incorrect or irregular for some reason. In the case of the value, there is a possibility that the auxiliary line L cannot be accurately estimated. On the other hand, by determining the inclination of the auxiliary line L based on the third direction vector V3, the auxiliary line L is changed even if some of the acceleration data shows an inaccurate value or an irregular value. It can be estimated accurately.

  Further, in the above embodiment, the protrusion amount n is calculated according to the number of limit acceleration data (step S37), and the second and third control points are determined based on the protrusion amount n (the above equation (5) and (6)). From the above equations (5) and (6), the positions of the second and third control points are further away from the region A indicating the range of the limit value as the protrusion amount n is larger. That is, the distance from the point B on the auxiliary line L farthest from the region A to the region A increases as the value of the protrusion amount n increases. Here, a large value of the protrusion amount n means that the number of limit acceleration data is large, and means that a period during which an actual value cannot be detected because the limit value range is exceeded is long. It is considered that the actual acceleration value during the period increases with the length of the period. Therefore, by increasing the distance from the point B of the auxiliary line L to the region A according to the protrusion amount n, an auxiliary line closer to the actual transition of acceleration can be calculated.

  Returning to FIG. 16, in step S23 and step S24 after step S22, the moving direction vector Vm is calculated from the corrected selected acceleration data group 631. The process for calculating the movement direction vector Vm is the same operation as the process in step S32. That is, the CPU 10 calculates a two-dimensional vector in the xy coordinate system based on the above equation (2). Step S22 differs from step S32 in that the calculation of the above equation (2) is performed using the selected acceleration data group 631 in which the limit acceleration data group 631 'included therein is corrected. By using the corrected selected acceleration data group 631, the moving direction vector Vm can be accurately calculated.

Specifically, first, in step S23, a difference vector group is calculated from the corrected selected acceleration data group 631. For each piece of acceleration data included in the selected acceleration data group 631, the CPU 10 calculates, for each acceleration data, the difference (difference vector) between the acceleration vector indicated by the acceleration data and the acceleration vector indicated by the next acquired acceleration data. calculate. Note that “(VA _{t + 1} −VA _t )” in the above equation (2) corresponds to this difference vector. Data indicating each difference vector calculated in step S23 is stored in the main memory 13 as a difference vector data group 640. Next, in step S <b> 24, the CPU 10 calculates a moving direction vector based on the difference vector data group 640 stored in the main memory 13. That is, the sum of each difference vector is calculated by weighting each difference vector according to the magnitude of the difference vector. Note that “| VA _{t + 1} −VA _t |” in the above equation (2) corresponds to the weight assigned to each difference vector. Further, the moving direction vector Vm calculated by the above equation (2) is normalized. That is, the length is corrected to “1”. Data indicating the movement direction vector Vm calculated by the above processing is stored in the main memory 13 as movement direction data 641.

上式（７）に示すように、重力方向ベクトルＶｇは、選出加速度データ群６３１に含まれる加速度ベクトルＶＡの総和として算出される。また、上式（７）で算出された重力方向ベクトルＶｇは正規化される、すなわち、長さが“１”に補正される。以上の処理によって算出された重力方向ベクトルＶｇを示すデータは、重力方向データ６４２としてメインメモリ１３に記憶される。以上のように算出された重力方向ベクトルＶｇは、ｘｙ座標系における原点を基準点としたとき、選出加速度データ群６３１に含まれる各加速度ベクトルの、基準点に対する偏りを示している。本実施形態では、この偏りを算出することによって重力方向を算出している。なお、上記偏りは、加速度ベクトルＶＡの総和を算出する方法に代えて他の方法によって算出されてもよい。 Next, in step S25, the gravity direction vector Vg is calculated based on the corrected selected acceleration data group 631. Specifically, the CPU 10 calculates the gravity direction vector Vg according to the following equation (7).

As shown in the above equation (7), the gravity direction vector Vg is calculated as the sum of the acceleration vectors VA included in the selected acceleration data group 631. Further, the gravity direction vector Vg calculated by the above equation (7) is normalized, that is, the length is corrected to “1”. Data indicating the gravity direction vector Vg calculated by the above processing is stored in the main memory 13 as gravity direction data 642. The gravity direction vector Vg calculated as described above indicates the deviation of each acceleration vector included in the selected acceleration data group 631 with respect to the reference point when the origin in the xy coordinate system is the reference point. In the present embodiment, the direction of gravity is calculated by calculating this bias. The bias may be calculated by another method instead of the method of calculating the sum of the acceleration vectors VA.

In subsequent step S <b> 26, the CPU 10 calculates a swing direction vector based on the movement direction data 641 and the gravity direction data 642 stored in the main memory 13. As described above, the swing direction vector is a vector indicating the direction in which the controller 7 moves with respect to the direction of gravity. Specifically, the CPU 10 performs rotation processing on both the movement direction vector Vm and the gravity direction vector Vg so that the gravity direction vector Vg faces a predetermined reference direction. Then, the rotated movement direction vector Vm is set as a swing direction vector Vs. The swing direction vector Vs is expressed in an XY coordinate system for representing a direction with respect to the gravity direction, whereas the movement direction vector Vm and the gravity direction vector Vg are based on the direction of the controller 7. Expressed in the xy coordinate system. Therefore, the rotation process is performed as coordinate conversion from the xy coordinate system to the XY coordinate system. Specifically, the CPU 10 calculates the swing direction vector Vs = (SX, SY) according to the following equation (8).
SX = −gy × mx + gx × my
SY = −gx × mx−gy × my (8)
In the above equation (8), the movement direction vector Vm is (mx, my), and the gravity direction vector Vg is (gx, gy). In the present embodiment, the XY coordinate system is an orthogonal coordinate system in which the gravity direction when the upper surface of the controller 7 is vertically upward is the Y axis negative direction. Therefore, the reference direction in the XY coordinate system is the direction of the negative Y-axis direction.

  FIG. 20 is a diagram showing the moving direction vector Vm and the gravity direction vector Vg in the xy coordinate system. FIG. 21 is a diagram showing a swing direction vector in the XY coordinate system. For example, when the movement direction vector Vm and the gravity direction vector Vg shown in FIG. 20 are calculated, the CPU 10 sets the movement direction vector Vm and the gravity direction vector Vg so that the gravity direction vector Vg is in the negative Y-axis direction. Coordinate transformation to rotate together. As shown in FIG. 21, the movement direction vector Vm after being rotated (after coordinate conversion) becomes the swing direction vector Vs.

  Data indicating the swing direction vector Vs obtained as described above is stored in the main memory 13 as swing direction data 643. After step S26, the CPU 10 ends the swing direction calculation process. In this embodiment, the swing direction is expressed by using a vector, but in other embodiments, the swing direction may be expressed by an angle. For example, the swing direction may be represented as a magnitude of an angle formed by the movement direction vector Vm and the gravity direction vector Vg.

  Returning to the description of FIG. 15, the process of step S9 is executed after step S8. That is, in step S9, the CPU 10 executes a game process corresponding to the swing direction calculated in step S8. Specifically, an animation in which the sword object 52 moves in a direction corresponding to the swing direction is displayed on the monitor 2 (see FIG. 11). Further, the CPU 10 determines whether or not the sword object 52 has come into contact with the log object 51 as a result of moving the sword object 52 in the game space. When the sword object 52 comes into contact with the log object 51, a state in which the log object 51 is cut along the trajectory of the sword object 52 is displayed (see FIG. 11). Further, although not shown in the flowchart shown in FIG. 15, when the log object 51 is cut, the cut log object 51 is displayed for a predetermined time, and then a new log object 51 is displayed. May be. Further, the log object 51 may be moved in the game space.

  In subsequent step S10, the operation flag is set to OFF. That is, the CPU 10 rewrites the contents of the operation flag data 644 stored in the main memory 13 to data indicating OFF. Thereby, when the loop process of steps S2 to S11 is performed next, the determination result of step S3 is negative. In step S9, the contents of the data 631 to 643 stored in the main memory 13 are cleared.

  In subsequent step S11, the CPU 10 determines whether or not to end the game. The determination in step S11 is, for example, whether or not the player has given an instruction to end the game, whether or not the player has cleared the game, and if the game has a time limit, the time limit has elapsed. It is done depending on whether or not. If the determination result of step S11 is negative, the process of step S2 is executed again, and thereafter, the process loop of steps S2 to S11 is executed until it is determined that the game is to be ended. On the other hand, when the determination result of step S11 is affirmative, the CPU 10 ends the process shown in FIG. Above, description of the process in the game device 3 is complete | finished.

  As described above, according to the present embodiment, acceleration data is acquired from the controller 7 (step S12), and two types of vectors, a moving direction vector Vm and a gravity direction vector Vg, are calculated from the acquired acceleration data ( Steps S23 to S25). Thus, in this embodiment, two types of information indicating the state of the controller 7 can be obtained from one type of information detected by the sensor. Then, the game apparatus 3 performs the game process by reflecting these two types of information on the game operation (step S9). This makes it possible for the player to perform a complicated game operation based on the two types of states of the controller 7 while having a simple configuration with one sensor.

  Further, according to the present embodiment, when the value of the acceleration data becomes the limit value, the value of the limit acceleration data group is corrected using the auxiliary line (step S22). That is, when the acceleration sensor 37 cannot detect the actual acceleration value, the game apparatus 3 estimates the actual acceleration value using the auxiliary line. Thereby, even if the actual acceleration value exceeds the limit value, the actual acceleration value can be accurately calculated. As a result, when calculating the state of the controller 7 (for example, the swing direction) using the calculated acceleration value, the state of the controller 7 can be calculated more accurately.

  In the above embodiment, the game apparatus 3 calculates the direction of gravity by calculating the sum of the acceleration vectors detected during the movement period (step S25). Here, since the acceleration vector detected during the movement period includes a component due to the movement of the controller 7 in addition to the component due to the gravity applied to the controller 7, it is detected during the movement period. The direction of gravity cannot be accurately recognized by the acceleration itself. On the other hand, in this embodiment, since the sum total of each acceleration vector detected during the movement period is calculated, the component due to the movement of the controller 7 in each acceleration vector is canceled out, and the gravity that is always detected is detected. It is possible to extract only the components resulting from. In particular, in the case of a game, it is important to recognize what kind of action a player performs, so that attention is paid to the start and end of the action. Therefore, the gravity direction with respect to the controller in one operation of the player accompanying the movement of the controller 7 can be recognized by the process of step S25.

  In the above embodiment, the game apparatus 3 calculates the movement direction vector based on the difference vector indicating the transition of the value of the selected acceleration data group 631. Specifically, the game device 3 calculates a difference vector for the selected acceleration data group 631, calculates a moving direction vector by calculating a sum by adding a predetermined weight to the difference vector (steps S23 and S24). . The predetermined weight is set to a value corresponding to the magnitude of the difference vector (the above formula (2)). The portion where the difference vector is large means that a quick swing is performed, and is a characteristic portion of the swing motion. Therefore, the size of each difference vector calculated from the selected acceleration data group 631 is small. The movement direction of the controller 7 can be calculated by highly evaluating a large difference vector as a characteristic part.

  As a method of calculating the moving direction, a method of simply calculating the sum of the difference vectors (without weighting) is also conceivable. In this method, the sum of the difference vectors is a vector whose starting point is the xy coordinate value of the acceleration vector at the start point of the moving period and whose ending point is the xy coordinate value of the acceleration vector at the end point. In the example shown in FIG. 15, the sum of the difference vectors is a vector having the point p0 as the start point and the point p19 as the end point. Depending on how the start time and end time of the moving period are detected, the moving direction of the controller 7 can be calculated also by the above method.

  Note that in the above method, the moving direction may not be accurately recognized. For example, when the acceleration vector at the start time of the movement period and the acceleration vector at the end time have substantially the same value, the movement direction may not be accurately recognized. This is because if the acceleration vector at the start time and the acceleration vector at the end time have the same value, the sum of the difference vectors becomes “0”. In the example shown in FIG. 15, the acceleration vector at the start point (point p1) and the acceleration vector at the end point (point p19) are greatly separated. However, depending on how the first and second threshold values are set, the acceleration vector at the start point and the acceleration vector at the end point may be substantially the same value. If the two acceleration vectors have substantially the same value, the direction of the vector indicating the sum of the difference vectors is not necessarily the direction corresponding to the moving direction.

  Therefore, in the above embodiment, the sum is calculated by adding a predetermined weight to the difference vector. As a result, even if the above two vectors have the same value, the vector indicating the sum is not “0”, and among the difference vectors, the component of the difference vector having a large size that is a characteristic part is included. It is represented by the total sum to be largely reflected. That is, the vector indicating the sum represents the moving direction of the controller 7. As described above, in step S25, the sum of the difference vectors may be simply calculated without weighting, but it is preferable to calculate the sum with the weight.

(Modifications related to auxiliary lines)
In the above embodiment, a Bezier curve is used as an auxiliary line for correcting acceleration data. Here, in another embodiment, the auxiliary line is not limited to a Bezier curve, and may be any one that estimates an actual acceleration value while acceleration data takes a limit value. That is, the auxiliary line may be a line that passes outside the detection range of the acceleration sensor 37. Note that it is not necessary for all of the auxiliary lines to pass outside the detection range, and it is sufficient that at least a part thereof passes outside the detection range.

  For example, a cardinal spline curve or a B-spline curve may be used as the auxiliary line instead of the Bezier curve. These curves are represented by functions that include one or more control points. When a curve represented by such a function is used, the shape of a complicated curve can be determined by determining the control point, so that the acceleration can be estimated in detail by the complex curve, and the curve is It can be easily calculated.

  Further, the auxiliary line is not limited to a curved line, and may be constituted by a broken line composed of a plurality of line segments. FIG. 22 is a diagram illustrating another example of the auxiliary line. In FIG. 22, the auxiliary line L ′ is composed of a line segment L1 and a line segment L2. The line segment L1 is a line segment that extends a line segment connecting the point p4 of the immediately preceding acceleration data and the point p3 of the acceleration data acquired immediately before the immediately preceding acceleration data to the outside of the point p4. The line segment L2 is a line segment that extends the line segment connecting the point p8 of the immediately following acceleration data and the point p9 of the acceleration data acquired immediately after the immediately following acceleration data to the outside of the point p8. When the auxiliary line L ′ is used, the process of calculating the auxiliary line can be simplified as compared with the case where the curve determined by the control points as described above is used. The inclination of the line segment L1 may be determined by the first direction vector V1, and the inclination of the line segment L2 may be determined by the second direction vector V2.

(Modified example of acceleration data order)
In the above embodiment, the detailed processing has been described by using a two-dimensional acceleration vector as an example. However, in another embodiment, the acceleration indicated by the acceleration data may be a three-dimensional acceleration value. The present invention can also be applied to a one-dimensional acceleration value. When a three-dimensional acceleration vector is used, an auxiliary line can be calculated in a three-dimensional xyz coordinate system in accordance with the case of the two-dimensional xy coordinate system.

  Further, when using a one-dimensional acceleration value, the two-dimensional coordinates having the acceleration value indicated by the acceleration data and time as axes are used to assist in the same manner as in the case of the two-dimensional xy coordinate system. A line can be calculated. FIG. 23 is a diagram illustrating a coordinate system when a one-dimensional acceleration value is used. In the coordinate system shown in FIG. 23, the horizontal axis represents time (t), and the vertical axis represents acceleration value (s). Points q1 to q9 indicate accelerations detected by the acceleration sensor. A dotted line C shown in FIG. 23 indicates a limit value of a range that can be detected by the acceleration sensor.

  In FIG. 23, points q3 to q7 indicate limit values. At this time, the game apparatus 3 calculates the auxiliary line L by the same method as in the above embodiment, and corrects the acceleration values of the points q3 to q7 so as to be the values on the auxiliary line L. If the variable x in the above embodiment is replaced with the variable t and the variable y is replaced with the variable s, the auxiliary line L can be calculated by the same method as in the above embodiment. Note that the points q3 'to q7' shown in FIG. 23 indicate the corrected acceleration values. By calculating the state of the controller 7 using the acceleration data group corrected as described above, the calculation can be performed more accurately than when the state of the controller 7 is calculated using the acceleration data group before correction. Further, the acceleration transition can be calculated more accurately with respect to the acceleration related to one axis.

  As described above, the present invention can be used as, for example, a game device or a game program for the purpose of calculating the moving direction of the input device in detail.

1 is an external view of a game system including a game device according to an embodiment of the present invention. Functional block diagram of game device 3 Perspective view of controller 7 Perspective view of controller 7 The figure which looked at controller 7 from the front Diagram showing the internal structure of the controller 7 Diagram showing the internal structure of the controller 7 Block diagram showing the configuration of the controller 7 The figure which shows the relationship between the inclination of the controller 7, and the output of an acceleration sensor The figure which shows the relationship between the inclination of the controller 7, and the output of an acceleration sensor Illustrated diagram outlining the state when performing game operations using the controller 7 The figure which shows an example of the game screen displayed on the monitor 2 in this embodiment The figure which shows an example of the game screen displayed on the monitor 2 in this embodiment The figure which shows the main data memorize | stored in the main memory 13 of the game device 3 The figure which shows an example of the selection acceleration data group 631 Main flowchart showing a flow of processing executed in the game apparatus 3 The figure which shows transition of the acceleration data acquired by step S2 during a certain period The flowchart which shows the detail of the swing direction calculation process (step S8) shown in FIG. The flowchart which shows the detail of the data correction process (step S22) shown in FIG. The figure which shows an example of each control point and auxiliary line to be determined The figure which shows another example of the correction method of limit acceleration data The figure which shows the moving direction vector Vm and the gravity direction vector Vg in xy coordinate system The figure which shows the swing direction vector Vs in XY coordinate system The figure which shows the other example of an auxiliary line The figure which shows a coordinate system in the case of using a one-dimensional acceleration value

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Game system 2 Monitor 3 Game apparatus 4 Optical disk 5 External memory card 7 Controller 8a, 8b Marker 10 CPU
13 Main Memory 32 Operation Unit 35 Imaging Information Calculation Unit 36 Communication Unit 37 Acceleration Sensor 40 Image Sensor 51 Log Object 52 Sword Object 61 Game Program

Claims (8)

A moving direction calculating device for calculating a moving direction of an input device,
Acquisition means for sequentially acquiring acceleration data output from a multi-axis acceleration sensor mounted on the input device;
Period detecting means for detecting, as a movement period, a period from the start of movement of the input device to the end of movement based on the acquired acceleration data;
Acceleration data is obtained for each of a plurality of acceleration data acquired during the movement period, when an acceleration vector is a vector whose components are acceleration values related to a plurality of axes among the acceleration values related to each axis indicated by the acceleration data. Difference calculation means for calculating a difference vector between the acceleration vector corresponding to the acceleration vector and the acceleration vector corresponding to the acceleration data acquired next to the acceleration data;
The difference vector calculated for each acceleration data acquired within the movement period is weighted according to the magnitude of the difference vector to calculate the sum of the difference vectors, and is determined by the vector indicated by the sum. A moving direction calculating device comprising: a moving direction calculating unit that sets the moving direction as the moving direction. The period detecting means includes
Start setting means for setting, as a start time of the movement period, a time point at which an acceleration value related to a predetermined one of the acceleration values related to each axis indicated by the acquired acceleration data exceeds a first threshold value;
End setting means for setting, as an end point of the movement period, a point in time at which an acceleration value related to a predetermined one of the acceleration values related to each axis indicated by the acquired acceleration data falls below a second threshold value. Item 2. The moving direction calculation device according to Item 1. The multi-axis acceleration sensor is a three-axis acceleration sensor,
The difference calculation means uses, as the acceleration vector, a vector whose components are acceleration values related to two axes other than the predetermined one axis among the acceleration values related to each axis indicated by the acceleration data. The moving direction calculation device described. A gravity direction calculating means for calculating a vector indicating a sum of acceleration vectors corresponding to a plurality of acceleration data acquired during the movement period as a gravity direction applied to the input device;
The movement direction calculation device according to claim 1, further comprising game processing means for executing a predetermined game process based on the movement direction and the gravity direction. A moving direction calculation program to be executed by a computer of a moving direction calculation device that calculates a moving direction of an input device,
An acquisition step of sequentially acquiring acceleration data output from a multi-axis acceleration sensor mounted on the input device;
A period detection step of detecting, as a movement period, a period from the start of movement of the input device to the end of movement based on the acquired acceleration data;
Acceleration data is obtained for each of a plurality of acceleration data acquired during the movement period, when an acceleration vector is a vector having acceleration values related to a plurality of axes among the acceleration values related to each axis indicated by the acceleration data. A difference calculating step of calculating a difference vector between an acceleration vector corresponding to the acceleration vector and an acceleration vector corresponding to the acceleration data acquired next to the acceleration data;
The difference vector calculated for each acceleration data acquired within the movement period is weighted according to the magnitude of the difference vector to calculate the sum of the difference vectors, and is determined by the vector indicated by the sum. A moving direction calculation program for causing the computer to execute a moving direction calculating step in which a moving direction is the moving direction. The period detection step includes
A start setting step of setting a time point at which an acceleration value related to a predetermined one of the acceleration values related to each axis indicated by the acquired acceleration data exceeds a first threshold as a start time of the movement period;
An end setting step of setting, as an end point of the movement period, a time point at which an acceleration value related to a predetermined one axis among acceleration values related to each axis indicated by the acquired acceleration data falls below a second threshold value. Item 6. The moving direction calculation program according to Item 5. The multi-axis acceleration sensor is a three-axis acceleration sensor,
In the difference calculating step, the computer uses, as the acceleration vector, a vector having acceleration components related to two axes other than the predetermined one axis among the acceleration values related to the axes indicated by the acceleration data. The moving direction calculation program according to claim 6. A gravity direction calculating step of calculating a vector indicating a sum of acceleration vectors corresponding to a plurality of acceleration data acquired during the movement period as a gravity direction applied to the input device;
The moving direction calculation program according to claim 5, further comprising a game processing step of executing a predetermined game processing based on the moving direction and the gravity direction.

Images