TWI476733B - Three-dimensional space motion reconstruction method and apparatus constructed thereby - Google Patents

Description

Motion track reconstruction method and device thereof

The present invention relates to a motion trajectory reconstruction method and apparatus thereof, and more particularly to a motion trajectory reconstruction method and apparatus for two-dimensional and three-dimensional motion trajectories in three-dimensional space.

A conventional method for reconstructing a motion trajectory and a device thereof, as disclosed in the "integrated input device" of the Republic of China Patent No. M313840, which comprises an integrated input device and an image processing device controlled by the integrated input device . The integrated input device has an inertial sensing unit, a signal processing unit and a wireless transmitting unit, so that the inertial sensing unit generates an electronic signal according to the swing state of the integrated input device, and the signal processing unit The electronic signal is converted into a cursor position signal, and the wireless transmitting unit transmits the cursor position signal to the image processing device. Finally, the image processing device can move the cursor displayed by the display device to the designated position according to the cursor position signal. Wherein, when the integrated input device is operated by a user to perform yaw rotation in a three-dimensional space, the inertial sensing unit senses gravity acceleration and gravitational acceleration of the integrated input device in a z-axis direction. a change, a gravitational acceleration component in a y-axis direction, and a yaw angular velocity in an X-axis direction as the electronic signal, and the signal processing unit converts the electronic signal into an x-axis and a z-axis, respectively. The deflection angle of the second axis is used as the cursor position signal.

However, since the conventional device directly converts the electronic signal generated by the inertial sensing unit into the cursor position signal and transmits the signal to the image processing device, the integrated input device cannot perform the drift error of the inertial sensing unit. The correction causes the user of the integrated input device to have difficulty positioning the cursor displayed by the display device at a specified position. In addition, since the above-mentioned conventional method uses only the two deflection angles of the integrated input device at a fixed position as the cursor position signal, the method is obviously not applicable to the integrated input device itself in three-dimensional space. In the case of displacement. However, when the user holds the integrated input device for actual operation in a three-dimensional space, it is extremely difficult to maintain the integrated input device without displacement and only yaw rotation, so the conventional device and method are obviously improved. necessary.

The invention provides a motion trajectory reconstruction method and a device thereof, which mainly reduce the computational complexity and the calculation amount of the algorithm by a trajectory reconstruction unit, thereby increasing the hardware computing performance and realizing the function of real-time operation, and the main purpose of the invention is .

The invention provides a motion trajectory reconstruction method and a device thereof, which mainly reduce motion trajectory error by a dynamic switch unit, and another object thereof.

In order to achieve the foregoing object, the technical means and the achievable functions of the present invention include: a motion track reconstruction device, comprising a signal sensing module, a computing module and a signal transmission Module. The signal sensing module senses the movement of the signal sensing module itself and generates a set of sensing signals; the computing module receives the sensing signal and has a dynamic switching unit and a track reconstruction unit connected in series. The signal transmission module has two ends connected to the signal sensing module and the dynamic switching unit of the computing module to transmit the sensing signal to the dynamic switching unit. The dynamic switch unit is provided with a plurality of threshold values. When the plurality of values of the sense signal are greater than or equal to the plurality of threshold values, the dynamic switch unit is in a conducting state, and the sensing signal and the operation result are sent. To the trajectory reconstruction unit; and when the plurality of values are respectively smaller than the plurality of threshold values, the dynamic switch unit is in an off state, that is, no signal is sent to the trajectory reconstruction unit; and the trajectory reconstruction unit outputs according to the dynamic switch unit The sensing signal and the operation result generate a projection track signal, and the two-dimensional motion track signal is formed by the projection track signal.

A method for reconstructing a motion trajectory, comprising: measuring a set of sensing signals by using a signal sensing module; sending the sensing signal to a computing module by a signal transmitting module; The plurality of values are respectively compared with the plurality of threshold values in the dynamic switching unit of the computing module, and when the plurality of values are greater than or equal to the plurality of threshold values, the sensing signal and the dynamic switching unit are The operation result is sent to a track reconstruction unit of the operation module; the operation result of the dynamic switch unit is projected onto the virtual projection plane to generate a projection track signal; and the virtual projection plane and the ground coordinates are obtained by the sensing signal calculation An angle between the projection planes of a trajectory, and a transformation matrix for converting the virtual projection plane to the trajectory projection plane; and converting the projection trajectory signal into a two-dimensional motion trajectory signal by the transformation matrix.

The above and other objects, features, and advantages of the present invention will become more apparent from the aspects of the appended claims. It is a flowchart showing the operation of the motion trajectory reconstruction method implemented by the motion trajectory reconstruction device of the preferred embodiment of the present invention. The motion track reconstruction device comprises a signal sensing module 1, a signal transmission module 2, and a computing module 3, wherein the signal sensing module 1 is for the user to hold and follow a desired input track in a three-dimensional space. Moving to generate a set of sensing signals corresponding to the input track by a signal sensing step; the signal transmitting module 2 transmits the sensing signal generated by the signal sensing module 1 to the computing mode After receiving the sensing signal generated by the signal sensing module 1, the computing module 3 performs a trajectory reconstruction operation step to obtain a two-dimensional motion trajectory signal. Thereby, the signal sensing module 1, the signal transmission module 2 and the computing module 3 can reconstruct the desired input trajectory into the two-dimensional motion trajectory signal. In addition, the computing module 3 can also perform an identification step to identify the two-dimensional motion track signal, and display the identification result of the two-dimensional motion track signal through a display module 4.

The signal sensing module 1 has an accelerometer 11 , a gyroscope 12 and a magnetometer 13 respectively connected to the signal transmitting module 2 . The accelerometer 11 is configured to measure an acceleration value A _i along each of three mutually perpendicular initial axes of the signal sensing module 1 when the signal sensing module 1 is moved, and the signal is sensed. The three initial axial systems of the module 1 are respectively an X' axis, a Y' axis and a Z'axis; the gyroscope 12 is configured to measure the signal sensing module 1 with the X' axis and Y respectively. The 'axis and Z' axis are the three angular velocity values generated by the rotating shaft, and the rotation directions generated by the X' axis, the Y' axis and the Z' axis are the rotation directions of the signal sensing module 1 in sequence. An angle [roll angle], a pitch angle, and a yaw angle, thereby obtaining an angular relationship between each initial axis of the signal sensing module 1 and a gravity direction g; the magnetometer 13 Then, a compensation signal is generated to compensate the angle of the gyroscope 12 in the direction of rotation output by the yaw angle. The three acceleration values A _i generated by the accelerometer 11 , the three angular velocity values generated by the gyroscope 12 , and the gravity direction g and the compensation signal generated by the magnetometer 13 constitute the sensing signal. In addition, the accelerometer 11 , the gyroscope 12 , and the magnetometer 13 can also be connected to the signal transmission module 2 through a filtering unit 14 to filter out the noise in the sensing signal by using the filtering unit 14 .

The signal transmission module 2 has two ends connected to the signal sensing module 1 and the computing module 3. When the signal transmission module 2 selects a signal transmission line and transmits the signal by wire, the two ends of the signal transmission module 2 are two signal transmission connectors; and when the signal transmission module 2 is selected as a wireless device When the transmission module uses the wireless mode for signal transmission, the two ends of the signal transmission module 2 are respectively a wireless signal transmitter and a wireless signal receiver, and the wireless signal transmitter is connected to the signal sensing module. In group 1, the wireless signal receiver is connected to the computing module 3. In addition, when the signal transmission module 2 is wirelessly transmitted, the transmission mode can be selected as a radio frequency transmission mode, an infrared transmission mode, or a Bluetooth transmission mode.

The computing module 3 has a dynamic switching unit 31, a track reconstruction unit 32, a storage unit 33 and an identification unit 34 connected in series. The dynamic switch unit 31 is connected to the signal transmission module 2, and detects the motion condition of the signal sensing module 1 by using the change of the acceleration values A _i of the sensing signals. The dynamic switch unit 31 is provided with a register 311 for recording the acceleration values A _{i of} the initial axes for a predetermined time and the speed values obtained by integrating the acceleration values A _i with time. V _i . In addition, when the dynamic switching unit 31 is in an ON state [ON], it outputs the sensing signal and the displacement amount of the signal sensing module 1 in each of the initial axial directions to the trajectory reconstruction unit 32; If the dynamic switch unit 31 is in an off state [OFF], no signal is output to the track reconstruction unit 32. In addition, for each of the initial axes, the dynamic switch unit 31 is pre-set with a plurality of threshold values, thereby reducing the drift error of the sensing signal. More specifically, the threshold values preset by the dynamic switch unit 31 of the present invention in each of the initial axes are preferably an acceleration threshold T _Ai and a velocity threshold T _vi . Preferably, when the acceleration threshold value T _Ai is to be determined, the signal sensing module 1 is preferably placed in a return-to-zero state and maintained for the predetermined time, and the signal sensing module 1 is obtained within the predetermined time. after the maximum acceleration values of a _i, 1 to 3 times the maximum value of the acceleration as a threshold T _Ai; Ruoyu determining the velocity and threshold T _Vi, the speed is preferably within a predetermined time value of V _i maximum. The value is taken as 0.5 to 1 times as the speed threshold T _Vi .

Please refer to FIG. 2, which is a flow chart showing the operation of the dynamic switch unit 31 of the present invention. The dynamic switch unit 31 first receives the sensing signal and sets itself to the off state. Then, a first judgment formula D1 is executed to determine "whether the dynamic switch unit 31 is in an on state". If the determination result of the first judgment formula D1 is YES, each acceleration value A _i is integrated with time to obtain each of the speed values V _i , and a second judgment formula D2 is executed; and if the first judgment is If the judgment result of the formula D1 is "NO", each of the acceleration values A _{i is} taken as an absolute value to obtain an acceleration absolute value E _Ai , and a third judgment formula D3 is executed.

The second judgment formula D2 of the dynamic switch unit 31 determines whether "the speed threshold value T _Vi has been set". If the determination result of the second judgment formula D2 is "YES", each of the speed values V _i is integrated with time to obtain the displacement amount in each of the initial axial directions, and each of the acceleration values A _{i is} taken as an absolute value to obtain An acceleration absolute value E _Ai , and each of the speed values V _{i is} taken to obtain an absolute speed value E _Vi , and then a fourth judgment formula D4 is performed; and if the second judgment formula D2 is judged as “No” Then, a fifth judgment formula D5 is executed.

The third judgment formula D3 of the dynamic switch unit 31 compares "whether the acceleration absolute value E _Ai is greater than the preset acceleration threshold value T _{Ai in} each of the initial axial directions". If the determination result of the third judgment formula D3 is YES, the dynamic switch unit 31 is set to the ON state, and each of the acceleration values A _i is integrated with time to obtain each of the speed values V _i , and then executed. The fifth judgment formula D5; if the judgment result of the third judgment formula D3 is "NO", the first judgment formula D1 is re-executed.

The fourth judgment formula D4 of the dynamic switch unit 31 compares "whether the acceleration absolute value E _{Ai is} smaller than the acceleration threshold value T _Ai , and the speed absolute value E _{Vi is} smaller than the speed threshold value T _Vi ". If the determination result of the fourth judgment formula D4 is "YES", the speed value V _i is set to 0, and a sixth judgment formula D6 is executed; if the judgment result of the fourth judgment formula D4 is "NO", The first judgment formula D1 is re-executed.

The fifth judgment formula D5 of the dynamic switch unit 31 determines "whether or not each of the speed values V _i obtained in the previous step is the maximum value within the predetermined time." If the determination result of the fifth judgment formula D5 is "YES", the speed threshold value T _Vi is re-determined, and each of the speed values V _i is integrated with time to obtain the displacement amount in each of the initial axial directions, and then re-executed. The first judgment formula D1; and if the determination result of the fifth judgment formula D5 is "NO", the speed value V _i is directly integrated into time to obtain the displacement amount in each of the initial axial directions, and the first execution is performed. A judgment formula D1.

The sixth judgment formula D6 of the dynamic switch unit 31 determines whether "all the sense signals input to the dynamic switch unit 31 have been processed by the dynamic switch unit 31". If the determination result of the sixth judgment formula D6 is "YES", the operation of the dynamic switch unit 31 is ended; and if the determination result of the sixth judgment formula D6 is "NO", the dynamic switch unit 31 is set again. This is the off state, and the first judgment formula D1 is re-executed.

Through the above operation flow, the dynamic switch unit 31 can send the displacement result of the sensing signal and the integral operation to the trajectory reconstruction unit 32 when the conduction state itself is in the on state, and the acceleration threshold value T can be utilized. _{The Ai} and the speed threshold T _Vi are judged so that the speed value V _{i is} reset to zero in time, thereby effectively reducing the error accumulated by the signal sensing module 1 over time [so-called drift error].

Referring to FIG. 1 again, and referring to FIG. 3 together, the trajectory reconstruction unit 32 generates a virtual projection plane P1 according to the amount of displacement in the initial axial direction output by the dynamic switch unit 31. The initial axis having the smallest average displacement amount among the three initial axes (for example, the Z' axis shown in FIG. 3) is the normal vector of the virtual projection plane P1, and the other two initial axes (for example, the third The X' axis and the Y' axis shown in the figure are the two base vectors of the virtual projection plane P1. Thereby, the desired input trajectory can be projected on the virtual projection plane P1 to generate a projection trajectory signal. When the trajectory reconstruction unit 32 is to calculate the virtual projection plane P1, it can also directly judge the acceleration value A _i in each initial axis of the sensing signal to have the initial axial direction with the minimum acceleration value A _i . The virtual projection plane P1 has a normal vector and uses the other two initial axes as the base vector of the virtual projection plane P1. Subsequently, the trajectory reconstruction unit 32 is further used as the initial axis of the normal vector of the virtual projection plane P1. To [as shown in Figure 3 The angle θ of the Z′ axis] and the gravity direction g generates a transformation matrix, and the projection trajectory signal is projected from the virtual projection plane P1 to the trajectory projection plane P2 of the earth coordinate to obtain the two-dimensional motion trajectory signal. The trajectory projection plane P2 can be selected as one of the horizontal planes or a vertical plane of the earth coordinates, and as shown in FIG. 3, the trajectory projection plane P2 is formed by the Z-axis of the earth coordinates as a normal vector. Horizontal plane.

More specifically, when the trajectory projection plane P2 is selected as the horizontal plane formed by the normal coordinate Z axis and the projection trajectory signal is rotated by the X' axis as the rotation axis, the projection is preferably performed. Select the conversion matrix as follows:

Thereby, after the matrix of the conversion matrix and the projection track signal are subjected to a matrix operation, the two-dimensional motion track signal can be obtained. In addition, as shown in FIG. 4, even if the virtual projection plane P1 is perpendicular to the trajectory projection plane P2, the projection trajectory signal can be projected to the trajectory projection plane P2 by the conversion matrix to obtain the trajectory projection plane. Two-dimensional motion track signal on P2. Finally, the storage unit 33 stores the two-dimensional motion track signal obtained by the track reconstruction unit 32; and the identification unit 34 identifies the two-dimensional motion track signal by an image recognition program, and the identification unit 34 is connected to The display module 4 is configured such that the display module 4 displays the identification result of the identification unit 34. In addition, the identification unit 34 can also be directly connected to the trajectory reconstruction unit 32 to perform image recognition on the two-dimensional motion trajectory signal in real time.

With the trajectory reconstruction unit 32 of the present invention, the virtual projection plane P1 can be generated only by using the acceleration value A _i and the measured gravity direction g, and the trajectory to be input in the three-dimensional space is projected to the virtual projection plane. The two-dimensional spatial trajectory signal [that is, the projection trajectory signal] is formed by P1, so that the computational complexity and the calculation amount of the algorithm when the virtual projection plane P1 is generated and the image recognition is performed can be effectively reduced. In addition, since the initial axis having the minimum acceleration value A _i is used as the normal vector of the virtual projection plane P1, the virtual projection plane P1 can be obtained in real time, so that the motion trajectory reconstruction method of the present invention is not subject to offline operation only. The limit.

By moving the signal sensing module 1 in a three-dimensional space according to a two-dimensional trajectory, the motion trajectory reconstruction device of the present invention can be used not only for track position control [such as cursor position control] but also for writing characters and recognizing Then, the display module 4 displays the depicted characters [for example, the character and signature can be instantly projected when the briefing is performed], and can be used to track the trajectory of the user's limb movement [eg medical rehabilitation and athlete training]. Alternatively, the signal sensing module 1 can be moved according to the edge of an object to accurately measure the shape of the object.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

1. . . Signal sensing module

11. . . Accelerometer

12. . . Gyro

13. . . Magnetometer

14. . . Filter unit

2. . . Signal transmission module

3. . . Computing module

31. . . Dynamic switching unit

311. . . Register

32. . . Trajectory reconstruction unit

33. . . Storage unit

34. . . Identification unit

4. . . Display module

A _i . . . Acceleration value

E _Ai . . . Absolute value of acceleration

E _Vi ‧‧‧speed absolute value

D1‧‧‧ first judgment

D2‧‧‧Second judgment

D3‧‧‧ third judgment

D4‧‧‧ fourth judgment

D5‧‧‧ fifth judgment

D6‧‧‧ sixth judgment

G‧‧‧gravity direction

P1‧‧‧Virtual projection plane

P2‧‧‧ trajectory projection plane

T _Ai ‧‧‧ Acceleration threshold

T _Vi ‧‧‧Speed threshold

V _i ‧‧‧ speed value

Θ‧‧‧ angle

Figure 1 is a flow chart showing the operation of the motion track reconstruction method and apparatus of the preferred embodiment of the present invention.

Figure 2 is a flow chart showing the operation of the dynamic trajectory unit of the preferred embodiment of the present invention.

Figure 3 is a schematic diagram showing the operation of the motion trajectory reconstruction method of the preferred embodiment of the present invention and the trajectory reconstruction unit of the apparatus for generating a two-dimensional motion trajectory signal.

FIG. 4 is a schematic diagram showing the operation of the trajectory reconstruction unit of the preferred embodiment of the present invention for generating a two-dimensional motion trajectory signal when the virtual projection plane is perpendicular to the trajectory projection plane.

1. . . Signal sensing module

11. . . Accelerometer

12. . . Gyro

13. . . Magnetometer

14. . . Filter unit

2. . . Signal transmission module

3. . . Computing module

31. . . Dynamic switching unit

311. . . Register

32. . . Trajectory reconstruction unit

33. . . Storage unit

34. . . Identification unit

4. . . Display module

Claims (17)

A motion track reconstruction device includes: a signal sensing module that senses movement of the signal sensing module itself and generates a set of sensing signals; and an operation module receives the sensing signal and has Connecting one of the dynamic switching units and a trajectory reconstruction unit, the trajectory reconstruction unit generates a virtual projection plane, and adopts an initial axis having a minimum acceleration value or a minimum average displacement amount as a normal vector of the virtual projection plane, and then The virtual projection plane generates a two-dimensional motion track signal by operation; a signal transmission module has a dynamic switching unit that is connected to the signal sensing module and the computing module at two ends to transmit the sensing signal to The dynamic switch unit is configured to have a plurality of threshold values. When the plurality of values of the sense signal are greater than or equal to the threshold values, the dynamic switch unit is in a conducting state, and the sense is The test signal and the operation result are sent to the track reconstruction unit; and when the plurality of values are respectively smaller than the plurality of threshold values, the dynamic switch unit is in an off state I.e., no signal sent to the trajectory reconstruction unit; the trajectory reconstruction unit generates a projection sensing signal according to the track dynamic switching unit outputs the sense signal and the calculation result, then the two-dimensional trajectory formed by a signal trace of the projection signal. The motion trajectory reconstruction device of claim 1, wherein the computing module further has a storage unit connected to the trajectory reconstruction unit, and the storage unit stores the two-dimensional motion trajectory signal. The motion trajectory reconstruction device according to item 2 of the patent application scope, wherein The computing module further has an identification unit connected to the storage unit, and the identification unit identifies the two-dimensional motion track signal. The motion trajectory reconstruction device according to the first aspect of the invention, wherein the computing module further has an identification unit connected to the trajectory reconstruction unit, and the identification unit identifies the two-dimensional motion trajectory signal. The motion track reconstruction device according to the third or fourth aspect of the patent application, wherein another display module is connected to the identification unit to display the identification result of the identification unit. According to the motion track reconstruction device of claim 1, wherein the two ends of the signal transmission module are respectively a wireless signal transmitter and a wireless signal receiver, and the wireless signal transmitter is connected to the signal sensing device. The module is connected to the wireless signal receiver. The motion track reconstruction device according to claim 1, wherein the signal transmission module is a signal transmission line, and the two ends are two signal transmission connectors. The motion track reconstruction device according to claim 6 , wherein the signal transmission module is selected from one of a radio frequency transmission mode, an infrared transmission mode, and a Bluetooth transmission mode. The motion trajectory reconstruction device according to claim 1, wherein the signal sensing module has an accelerometer, a gyroscope and a magnetometer, and the accelerometer, the gyroscope and the magnetometer are respectively connected to the signal Transfer module. The motion track reconstruction device according to claim 1, wherein the signal sensing module has an accelerometer, a gyroscope and a magnetometer, and the accelerometer, the gyroscope and the magnetometer are respectively connected to a filter. The unit is further connected to the signal transmission module by the filtering unit. A method for reconstructing a motion trajectory, comprising: measuring a set of sensing signals by using a signal sensing module; sending the sensing signal to a computing module by a signal transmitting module; The plurality of values are respectively compared with the plurality of threshold values in the dynamic switching unit of the computing module, and when the plurality of values are greater than or equal to the plurality of threshold values, the sensing signal and the dynamic switching unit are The operation result is sent to a trajectory reconstruction unit of the operation module, the trajectory reconstruction unit generates a virtual projection plane, and the initial axis having the minimum acceleration value or the minimum average displacement amount is used as the normal vector of the virtual projection plane; The operation result of the dynamic switch unit is projected onto the virtual projection plane to generate a projection trajectory signal; the angle between the virtual projection plane and the trajectory projection plane of one of the geodetic coordinates is calculated by the sensing signal, and a transformation matrix is generated. The conversion matrix is configured to convert the virtual projection plane to the trajectory projection plane; converting the projection trajectory signal into a two-dimensional image by using the transformation matrix The movement path of the signal. The motion trajectory reconstruction method according to claim 11, wherein the sensing signal includes an acceleration value measured in three mutually perpendicular initial axes, and the threshold value includes three acceleration threshold values to respectively The three acceleration values are compared. The method for reconstructing a motion trajectory according to claim 12, wherein the three accelerations are sent after the sensing signal is sent to the computing module The value is integrated over time to obtain three velocity values, and the threshold value includes three velocity threshold values to be compared with the three velocity values, respectively. The motion trajectory reconstruction method according to claim 11, wherein the two-dimensional motion trajectory signal is stored in a storage unit after the two-dimensional motion trajectory signal is obtained. The method for reconstructing a motion trajectory according to claim 14, wherein after the two-dimensional motion track signal is stored in the storage unit, the two-dimensional motion track signal stored in the storage unit is identified by an identification unit. The method for reconstructing a motion trajectory according to claim 11 , wherein after the two-dimensional motion trajectory signal is obtained, the two-dimensional motion trajectory signal is identified by an identification unit. The method for reconstructing a motion trajectory according to claim 15 or 16, wherein after the identification unit generates the identification result of the two-dimensional motion track signal, the recognition result is displayed by a display module.