Motion capture equipment, charging base, time synchronization method and system and motion capture system

Abstract

The invention relates to wireless communication motion capture equipment, a charging base, a time synchronization method and system and a motion capture system. The wireless communication motion capture equipment comprises a basic module, a synchronous contact, a charging contact and a first control module, the first control module is respectively connected with the basic module, the synchronous contact and the charging contact, drives the basic module to complete a main body function, sends out a confirmation signal in response to a synchronous command signal received by the charging contact, receives a synchronous signal through the synchronous contact, and then executes a timestamp alignment operation. Compared with the traditional protocol-based synchronization mode, the time stamp synchronization is assisted by hardware, so that the method is more accurate, and meanwhile, the system provides an accurate synchronization signal, so that the high consistency of each part in time is ensured. The accuracy avoids the synchronization error caused by the complexity or limitation of the protocol, thereby improving the accuracy and reliability of the whole motion capture device and method.

Description

Technical Field

[0001] The present invention relates to the field of motion capture technology, and in particular to a wireless communication motion capture device, a charging base, a time synchronization method, a system and a motion capture system. Background Art

[0002] Inertial motion capture technology is an advanced human motion capture technology that uses wireless motion gesture sensors to collect the posture and orientation of body parts and uses the principles of human kinematics to restore the human motion model. This technology uses wireless transmission to present data in computer software. It has the advantages of high adaptability, technical advantages, cost advantages and ease of use, making it widely used in film and television animation, experiential interactive games, virtual studios, real-life simulation exercises, sports training, medical rehabilitation and other fields.

[0003] Inertial motion capture systems usually use wireless communication to transmit data. The advantage of this is that it can provide greater freedom of movement, is not restricted by the site, and can avoid interference and inconvenience caused by cables. Commonly used wireless communication methods include: 2.4GHz / 5.8GHz single-frequency or dual-frequency WiFi communication, low-power Bluetooth technology. These wireless communication technologies working in the above frequency bands are generally congested, and it is difficult to ensure both real-time communication and data integrity, which often causes display freezes and data calculation errors. Especially when multiple wireless motion capture devices are networked and linked at the same time, the synchronization of timestamps is not accurate enough, resulting in the misalignment of the time point of the motion capture data, and even data transmission errors, resulting in inaccurate detection. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, one of the objectives of the present invention is to provide a wireless communication motion capture device that performs timestamp calibration through hardware to reduce the error of data detection.

[0005] A second object of the present invention is to provide a charging stand.

[0006] A third object of the present invention is to provide a time synchronization method for wireless communication motion capture equipment.

[0007] A fourth object of the present invention is to provide a time synchronization method for a wireless communication motion capture device applied to a charging station.

[0008] A fifth object of the present invention is to provide a time synchronization system for wireless communication motion capture equipment.

[0009] A sixth object of the present invention is to provide a motion capture system.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] In one aspect, the present invention provides a wireless communication motion capture device, comprising: a basic module, a synchronization contact, a charging contact, and a first control module;

[0012] The first control module is respectively connected to the basic module, the synchronization contact and the charging contact, drives the basic module to complete the main function, sends a confirmation signal in response to the synchronization command signal received by the charging contact, receives the synchronization signal through the synchronization contact, and then performs the timestamp alignment operation.

[0013] Preferably, the wireless communication motion capture device includes a docking position, and the synchronization contacts and the charging contacts are installed on the docking position.

[0014] Preferably, the docking position is a planar structure or an eccentric structure.

[0015] Preferably, the docking position includes a magnetic attraction component.

[0016] Preferably, the basic module includes a motion capture unit, a first wireless communication module, and an energy storage module;

[0017] The motion capture unit and the first wireless communication module are connected to the first control module respectively; the energy storage module is connected to the charging contact.

[0018] Preferably, the synchronization contact comprises one or more small contacts.

[0019] On the other hand, the present invention provides a charging stand, comprising: a power module, a synchronization ejector pin, a charging ejector pin, and a second control module;

[0020] The power module is connected to the charging pin;

[0021] The second control module is connected to the synchronization pin and the charging pin respectively, sends a synchronization command signal through the charging pin, and sends a synchronization signal through the synchronization pin in response to a confirmation signal received by the charging pin.

[0022] Preferably, the number of the synchronous ejector pins is one or more; the number of the charging ejector pins is one or more;

[0023] A synchronization pin and a charging pin are associated with each other.

[0024] Preferably, the charging station includes one or more charging positions;

[0025] Each of the charging positions has a synchronization pin and a charging pin associated with the synchronization pin.

[0026] Preferably, the charging position is a planar structure or an eccentric structure.

[0027] On the other hand, the present invention provides a wireless communication motion capture device time synchronization method, which is applied to the wireless communication motion capture device, comprising:

[0028] In response to a synchronization command signal received by the charging contact, sending a determination signal through the charging contact to enter a synchronization mode;

[0029] The timestamp alignment is performed in response to a synchronization signal received by the synchronization contact.

[0030] Preferably, the synchronization signal is a synchronization square wave of a predetermined period; and the timestamp alignment specifically includes:

[0031] Obtaining a time point corresponding to the first rising edge of the received synchronization square wave as a pre-adjustment timestamp;

[0032] The predetermined time value transmitted by the host computer is obtained by wireless communication, and the preset timestamp is adjusted to the predetermined time value.

[0033] Preferably, when the charging operation of the wireless communication motion capture device ends, the timestamp is maintained by a built-in timer and / or a time calibration signal of a host computer.

[0034] On the other hand, the present invention provides a method for time synchronization of a wireless communication motion capture device, which is applied to a charging station, comprising:

[0035] In response to the charging contact connection operation of the wireless communication motion capture device, a synchronization command signal is sent through the charging ejector pin at a fixed time;

[0036] In response to the determination signal received through the charging pin, a synchronization signal is sent through the synchronization pin.

[0037] Preferably, there are one or more synchronization pins; there are one or more charging pins; one synchronization pin is associated with one charging pin;

[0038] The synchronization method comprises:

[0039] When a charging contact performs a charging access operation, a synchronous command signal is sent through the charging pin corresponding to the charging contact at a fixed time;

[0040] In response to a determination signal received through the charging pin corresponding to the charging contact, a synchronization signal is sent through a synchronization pin associated with the charging pin.

[0041] Preferably, when a plurality of the wireless communication motion capture devices are charged in the same time period, the following steps are included:

[0042] Sending synchronization commands to all the wireless communication motion capture devices simultaneously and regularly;

[0043] After receiving the confirmation signals fed back by all the wireless communication motion capture devices, the synchronization signal is triggered for all the wireless communication motion capture devices simultaneously or in a predetermined order.

[0044] On the other hand, the present invention provides a wireless communication motion capture device time synchronization system, comprising any of the above-mentioned charging bases and any of the above-mentioned wireless communication motion capture devices.

[0045] In another aspect, the present invention provides a motion capture system, comprising:

[0046] One or more wireless communication motion capture devices as described in any one of the above;

[0047] The signal receiving end exchanges data with the wireless communication motion capture device via wireless communication.

[0048] Preferably, the wireless communication motion capture device starts with an integer second delay and sends data at fixed intervals according to the set frame rate; and saves the data to a local memory at the same time;

[0049] When the wireless communication motion capture device stops sending data, it enters a retransmission mode, responds to the missing frame retransmission request queried by the signal receiving end, and retransmits the frame number corresponding to the missing frame retransmission request.

[0050] Compared with the prior art, the wireless communication motion capture device, charging station, time synchronization method, system and motion capture system provided by the present invention have the following beneficial effects:

[0051] After receiving the synchronization command signal through the charging contact, the wireless communication motion capture device will enter the synchronization mode, and then receive the synchronization signal through the synchronization contact to achieve the timestamp alignment synchronization operation. The hardware is used to assist in the timestamp synchronization, which is more accurate than the traditional protocol-based synchronization method. At the same time, the system provides accurate synchronization signals to ensure the high consistency of each part in time. This accuracy avoids the synchronization error caused by the complexity or limitations of the protocol itself, thereby improving the accuracy and reliability of the entire motion capture device and method.

[0052] It should be noted that by using the charging contacts for data communication to receive synchronization command signals and send confirmation signals, no additional hardware communication contacts are required, the use of contacts is reduced, and the number of openings in the device casing is reduced. That is, the number of locations where the casing needs to be sealed is reduced, greatly reducing the possibility of water leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a structural block diagram of the wireless communication motion capture device provided by the present invention.

[0054] Figure 2It is a structural block diagram of the charging base provided by the present invention.

[0055] Figure 3 It is a flow chart of a time synchronization method for wireless communication motion capture equipment provided by the present invention.

[0056] Figure 4 It is a flow chart of a time synchronization method for a wireless communication motion capture device applied to a charging base provided by the present invention.

[0057] Figure 5 It is a structural block diagram of an embodiment of the time synchronization system of the wireless communication motion capture device provided by the present invention.

[0058] Figure 6 It is a flow chart of an embodiment of a time synchronization method for a wireless communication motion capture device provided by the present invention.

[0059] Figure 7 It is a flow chart of the use of the motion capture system provided by the present invention.

[0060] Figure 8 It is a structural block diagram of the motion capture system provided by the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0062] Those skilled in the art will appreciate that the foregoing general description and the following detailed description are exemplary and illustrative of specific embodiments of the present invention and are not intended to limit the present invention.

[0063] The terms "comprises," "includes," or any other variations thereof herein are intended to cover a non-exclusive inclusion, such that a process or method that includes a list of steps includes not only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, a reference to one or more devices or subsystems, elements or structures or components preceded by "comprises ... an" does not, without more limitations, exclude the presence of other devices or other subsystems or other elements or other structures or other components or other devices or other subsystems or other elements or other structures or other components. Throughout the specification, appearances of the phrases "in one embodiment," "in another embodiment," and similar language may, but do not necessarily, all refer to the same embodiment.

[0064] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0065] The principle of inertial motion capture technology: Inertial motion capture technology is mainly based on inertial measurement unit (IMU) sensors, which are usually composed of accelerometers and gyroscopes, and sometimes magnetometers. Accelerometers measure the acceleration of objects, gyroscopes measure the angular velocity of objects, and magnetometers are used to locate the direction of objects in magnetic fields. The data collected by these sensors are fused and processed through complex algorithms to infer the user's posture and movements. Common algorithms include Kalman filters, particle filters, and quaternion filters, which can handle noise and errors in sensor data and extract accurate motion information.

[0066] See also Figure 1 The present invention provides a wireless communication motion capture device (i.e., a motion capture device that can send motion capture data to a host computer wirelessly), including: a basic module, a synchronization contact, a charging contact, and a first control module; specifically, the basic module includes a sensor detection for completing motion capture, and in this embodiment, a sensor unit commonly used in the art is used as the basic module. Of course, in some embodiments, the basic module can add different sensor integrations according to different scene requirements, and the present invention does not limit this.

[0067] The first control module is respectively connected to the basic module, the synchronization contact and the charging contact, drives the basic module to complete the main function, sends a confirmation signal in response to the synchronization command signal received by the charging contact, receives the synchronization signal through the synchronization contact, and then performs the timestamp alignment operation.

[0068] It should be noted that the timestamp alignment operation is generally completed by synchronizing the time value sent by the host computer. This embodiment combines hardware and software communication to complete the timestamp alignment of the wireless communication motion capture device, thereby improving the accuracy of the timestamp alignment.

[0069] In some embodiments, the first control module is preferably an MCU (Microcontroller Unit), which is connected to the synchronization contact through an IO port. Of course, in other embodiments, other high-power controllers can also be selected as the first control module.

[0070] In a specific implementation, the synchronization command can be sent by the charging station, that is, when the wireless communication motion capture device is charged, the charging station sends the synchronization command, so that the timestamp synchronization function is integrated with the charging station, and the timestamp of the wireless communication motion capture device can be aligned and calibrated while charging. Of course, the command can also be implemented by other host computers with charging functions, as long as the above operations can be implemented.

[0071] In this embodiment, the wireless communication motion capture device is placed or connected to a charging base, and after the charging contacts and the charging pins are connected and can be charged, the charging base will send a synchronization command to the wireless communication motion capture device through the charging pins, and after receiving the synchronization command, the wireless communication motion capture device will feedback the confirmation signal through the charging contacts. When the charging base receives the confirmation signal, it sends a synchronization signal through the synchronization pin connected to the synchronization contact, and the wireless communication motion capture device performs timestamp synchronization according to the synchronization signal. It can be imagined that the synchronization signal in this embodiment is not limited in the manner, and can be synchronized by the current timestamp signal processing method.

[0072] The external interface (the charging contact and the synchronization contact) of the wireless communication motion capture device adopts a contact method, which can ensure the flatness of the shell.

[0073] See also Figure 5 As a preferred solution, the first control module is connected to the charging contact through a 1-Wire bus. Specifically, the 1-Wire bus is a simple signal transmission circuit that can realize two-way alternating communication between the first control module and one or more slave devices through a common data line. In the present invention, the communication between the first controller and the charging seat through the charging contact-charging pin (in the charging seat) can be effectively improved.

[0074] In any of the aforementioned embodiments, the synchronization contacts and the charging contacts may be installed in different positions (in which case they may be connected to the charging base via synchronization terminals or the like), or they may be installed in close positions (in which case the distance between the two is relatively close, and the installation positions of the charging pins and synchronization pins on the corresponding charging base are close).

[0075] As a preferred solution, the wireless communication motion capture device further includes a docking position, and the synchronization contact and the charging contact are installed on the docking position. For example, a circular ring or a square ring can be used on the shell of the wireless communication motion capture device to enclose the synchronization contact and the charging contact to form the docking position. The docking position can be higher or lower than the shell of the wireless communication motion capture device, so as to facilitate docking with the charging base.

[0076] Furthermore, in some embodiments, the docking position also has a snap-on design for snapping the wireless communication motion capture device with the charging base when charging. Correspondingly, the docking position of the charging base has a corresponding snap-on design to facilitate the docking of the two.

[0077] As a preferred solution, the docking position is a planar structure or an eccentric structure. Preferably, the eccentric structure can be an L-shaped structure, and the charging contact and the synchronization contact are respectively installed on one side of the eccentric structure for easy use.

[0078] As a preferred solution, the docking position includes a magnetic attraction component. Correspondingly, the docking position of the charging base also has a magnetic attraction component to facilitate docking.

[0079] See also Figure 5 As a preferred solution, the basic module includes a motion capture unit, a first wireless communication module, and an energy storage module; preferably, the motion capture unit includes at least an inertial measurement unit (IMU). Of course, in order to obtain the corresponding action, a corresponding detection sensor can be configured. The first wireless communication module includes one or more of a WiFi communication module, a Bluetooth communication module, a ZigBee communication module, and a GPRS communication module. The energy storage module is preferably a rechargeable battery for powering the built-in system of the wireless communication motion capture device. The preferred energy storage module includes a battery unit and a charging circuit. The battery unit is preferably a lithium battery. The battery unit is connected to the charging contact through the charging circuit. When the charging contact is connected to the charging power, the battery unit is charged through the charging circuit.

[0080] The motion capture unit and the first wireless communication module are connected to the first control module respectively; the energy storage module is connected to the charging contact.

[0081] As a preferred solution, the motion capture unit is connected to the first control module via an SPI bus or an I2C bus. The SPI (Serial Peripheral Interface) bus is usually used for high-speed data transmission and is suitable for a master-slave architecture, in which a master device can communicate in full-duplex with one or more slave devices. The I2C (Inter-Integrated Circuit) bus is a multi-host communication protocol for low-speed devices. It implements bidirectional data transmission through two lines (SDA and SCL) and supports multiple devices sharing the same communication line. Ensure stable data transmission between the motion capture unit and the first control module.

[0082] The preferred embodiment of the wireless communication motion capture device is composed of an MCU, an inertial measurement unit (IMU), a memory chip (Flash), a 1-wire charging bus chip, a wireless communication module, a synchronization contact, and a charging contact. The MUC is connected to the IMU via an SPI / I2C bus to collect its data. The MCU is connected to the Flash to send data and save the data locally. The MCU is connected to the wireless communication module and communicates with the receiver using 2.4G communication. The MCU is connected to the synchronization contact via the IO port to receive the synchronization square wave. The MCU uses a serial port to connect to the 1-wire charging bus chip to receive the synchronization command signal from the charging seat and switch the working mode of the wireless communication motion capture device.

[0083] As a preferred solution, the synchronization contact includes one or more small contacts. Further, the multiple small contacts can trigger multiple synchronization signals at the same time and perform time stamp calibration at the same time.

[0084] See also Figure 3 The present invention also provides a wireless communication motion capture device time synchronization method, which is applied to the wireless communication motion capture device, comprising:

[0085] In response to a synchronization command signal received by the charging contact, sending a determination signal through the charging contact to enter a synchronization mode;

[0086] In response to the synchronization signal received by the synchronization contact, the timestamp alignment is performed. That is, the wireless communication motion capture device will perform the timestamp alignment operation after receiving the synchronization signal.

[0087] As a preferred solution, the synchronization signal is a synchronization square wave of a predetermined period; and the timestamp alignment specifically includes:

[0088] Obtaining a time point corresponding to the first rising edge of the received synchronization square wave as a pre-adjustment timestamp;

[0089] The predetermined time value transmitted by the host computer is obtained by wireless communication, and the pre-adjusted timestamp is adjusted to the predetermined time value. That is, the timestamp calibration is performed by combining software and hardware, which is more accurate than the traditional protocol-based synchronization method. At the same time, the system provides an accurate synchronization signal to ensure the high consistency of each part in time. This accuracy avoids the synchronization error caused by the complexity or limitations of the protocol itself, thereby improving the accuracy and reliability of the entire motion capture device and method. The host computer includes a communication device, a PC, a mobile terminal, etc. connected to the wireless communication motion capture device.

[0090] The wireless communication motion capture device has a clock module that can increase over time. However, since there is no backup battery to maintain the clock operation, the power-on time of the device will be inconsistent, resulting in inconsistent operating clocks for each device. In this embodiment, when the device obtains a synchronous rising edge through the synchronization contact, it triggers the time calibration operation with the highest level hardware interrupt. The time of the wireless communication motion capture device will obtain the predetermined time value transmitted by the host computer through the software interface, set the system time to the predetermined time value, and make the timestamp calibration more accurate through the collaborative work of software and hardware.

[0091] As a preferred solution, the synchronization signal is a synchronization square wave of a predetermined period. Furthermore, the synchronization square wave is a PWM square wave sent by the charging station. PWM (Pulse Width Modulation) controls the analog signal strength by adjusting the duty cycle of the signal (i.e., the ratio of the high level of the signal to the total time of the cycle). The PWM square wave is usually composed of a series of periodic square waves. The high frequency of these square waves makes it impossible for the human eye or other sensors to distinguish individual switching actions, but to perceive a continuous analog signal. In a preferred embodiment, the predetermined period is 1-10ms, and more preferably 1ms, which greatly improves time synchronization.

[0092] As a preferred solution, when the charging operation of the wireless communication motion capture device is completed, the timestamp is maintained through the built-in timer and / or the time calibration signal of the host computer.

[0093] See also Figure 2 The present invention also provides a charging stand, comprising: a power module, a synchronous ejector pin, a charging ejector pin, and a second control module; preferably, the power module is used to provide charging power, which can be connected to the mains or a DC charging current (such as a 5V 1A charging head), and the charging stand is connected to an external power supply through the power module. The second controller is preferably an MCU (Microcontroller Unit), which is connected to the synchronous ejector pin through an IO port.

[0094] The power module is connected to the charging pin;

[0095] The second control module is connected to the synchronization pin and the charging pin respectively, sends a synchronization command signal through the charging pin, and sends a synchronization signal through the synchronization pin in response to a confirmation signal received by the charging pin. The charging pin is set corresponding to the charging contact, and the synchronization pin is set corresponding to the synchronization contact.

[0096] As a preferred solution, the second control module is connected to the charging pin via a 1-Wire bus.

[0097] The preferred embodiment of the charging stand is composed of a microcontroller (MCU), a power module, and a charging ejector pin. The MCU is connected to the positive electrode of the charging ejector pin through a 1-Wire bus (commonly used in wireless Bluetooth headsets) and is connected to the synchronization ejector pin through an IO pin. The power module is connected to the charging ejector pin.

[0098] As a preferred solution, the number of the synchronous ejector pins is one or more; the number of the charging ejector pins is one or more;

[0099] One of the synchronization ejector pins is associated with one of the charging ejector pins. Preferably, the number of associated pairs is preferably 10-20, and more preferably 18.

[0100] In some embodiments, the second control module may include one or more microcontrollers. When the second control module has multiple microcontrollers, group connection may be performed, for example, one or more associated pairs may be connected to one microcontroller.

[0101] As a preferred solution, the charging base further includes one or more charging positions, and the charging positions are arranged corresponding to the docking positions on the wireless communication motion capture device. Preferably, the number of the charging positions is preferably 10-20, preferably 18.

[0102] Each of the charging positions has a synchronization pin and a charging pin.

[0103] As a preferred solution, the charging position is a planar structure or an eccentric structure. Specifically, when the docking position is an L-shaped structure, the charging position is also an L-shaped structure, the difference being that the contacts (synchronization contacts and charging contacts) of the docking position are installed on the outer layer of the L-shaped structure, and the ejectors (synchronization ejectors and charging ejectors) of the charging position are installed on the inner side of the L-shaped structure.

[0104] See also Figure 4 The present invention also provides a method for synchronizing time of a wireless communication motion capture device, which is applied to a charging station and includes:

[0105] In response to the charging access operation of the charging contacts of the wireless communication motion capture device, a synchronization command signal is periodically sent through the charging pin; specifically, the timing duration is preferably 0.5-3s, and further preferably 1s.

[0106] In response to the determination signal received through the charging pin, a synchronization signal is sent through the synchronization pin.

[0107] In this embodiment, the charging pin and the synchronization pin on the charging base are a pair, that is, only one of the wireless communication motion capture devices is charged at a time, and a timestamp synchronization operation is performed.

[0108] As a preferred solution, the number of the synchronous ejector pins is one or more; the number of the charging ejector pins is one or more; one synchronous ejector pin is associated with one charging ejector pin;

[0109] The synchronization method comprises:

[0110] When a charging contact performs a charging access operation, a synchronous command signal is sent through the charging pin corresponding to the charging contact at a fixed time;

[0111] In response to the confirmation signal received by the charging pin corresponding to the charging contact, a synchronization signal is sent through the synchronization pin associated with the charging pin. This ensures that when one or more wireless communication motion capture devices are connected for charging, data disorder does not occur, improves the stability of synchronization signal transmission, and thus achieves stable synchronization of the timestamp of the wireless communication motion capture device.

[0112] As a preferred solution, when a plurality of the wireless communication motion capture devices are charged in the same time period, the following steps are included:

[0113] Sending synchronization commands to all the wireless communication motion capture devices simultaneously and regularly;

[0114] After receiving the confirmation signal fed back by all the wireless communication motion capture devices, the synchronization signal is triggered for all the wireless communication motion capture devices simultaneously or in a predetermined order. In this embodiment, it can be ensured that all wireless communication motion capture devices connected to charging are time-stamp aligned at the same time, thereby ensuring the time stamp synchronization of all wireless communication motion capture devices connected to charging, thereby improving the time accuracy of a motion capture system.

[0115] The predetermined order is not limited and may be sorted according to the corresponding numbers of the charging bases, or according to the access order of the wireless communication motion capture devices.

[0116] See also Figure 5 The present invention also provides a wireless communication motion capture device time synchronization system, comprising the charging base described in any of the above embodiments, and the wireless communication motion capture device described in any of the above embodiments.

[0117] Specifically, in this embodiment, when the wireless communication motion capture device is connected to the charging base for charging, the charging base sends a synchronization command signal to the wireless communication motion capture device at a fixed time (such as 1s), and the wireless communication motion capture device feeds back a confirmation signal to the charging base after receiving the synchronization command signal, and enters the synchronization mode to wait for the square wave; after receiving the confirmation signal, the charging base sends a synchronization signal (synchronous square wave) of a predetermined period (such as 1ms); the wireless communication motion capture device detects the rising edge of the first square wave of the synchronization square wave as a timestamp alignment.

[0118] See also Figure 6 , the execution steps of the wireless communication motion capture device time synchronization system include:

[0119] Step S100: The wireless communication motion capture device is placed in a charging base, and the charging base then charges the wireless communication motion capture device.

[0120] Step S200: The charging station sends a synchronization command regularly via the 1-wire bus, and waits for the collector to return a confirmation message.

[0121] Step S300: The wireless communication motion capture device receives a synchronization command and enters a synchronization mode; in the synchronization mode, while charging, the device waits for a square wave of the synchronization contact to appear.

[0122] Step S400: The charging base sends a PWM square wave to the synchronization pin, the pin is connected to the contact, and the first control module of the wireless communication motion capture device receives the synchronization square wave of the synchronization contact through the IO.

[0123] Step S500, the wireless communication motion capture device triggers the timestamp alignment through the rising edge of the synchronization square wave of the synchronization contact, and the rising edge of the first square wave is selected, so as to achieve the highest synchronization accuracy (nanosecond level).

[0124] Step S600: The wireless communication motion capture device is taken out of the charging base, and the timestamp is maintained according to the timer. The wireless communication motion capture device increments the timestamp according to its own heartbeat.

[0125] Preferably, the hardware solution of the synchronization system consists of two parts: wireless communication motion capture equipment and charging. One charging station can charge 18 wireless communication motion capture devices at the same time. The collector is connected to the charging station through charging contacts and synchronization contacts.

[0126] See also Figure 8 The present invention also provides a motion capture system, comprising:

[0127] One or more wireless communication motion capture devices as described in any of the above embodiments; of course, the acquisition frame rate (i.e. the frequency of sensor acquisition) of the wireless communication motion capture device can be set in idle state through the host computer software.

[0128] The signal receiving end includes a second wireless communication module, and data is exchanged with one or more of the wireless communication motion capture devices through the second wireless communication module. The signal receiving end can be a PC end or an independent data processing end or a data transfer end. After the PC end or the independent data processing end receives the data from the wireless communication motion capture device, it can process the data (in this case, the signal receiving end is used as a host computer). After the data transfer end receives the data from the wireless communication motion capture device, it sends the data to the PC end (in this case, the PC end is used as a host computer). The second wireless communication module includes one or more of a WiFi communication module, a Bluetooth communication module, a ZigBee communication module, and a GPRS communication module, and is set corresponding to the first wireless communication module.

[0129] As a preferred solution, the wireless communication motion capture device starts with a delay of an integer number of seconds and sends data at fixed intervals according to the set frame rate; at the same time, the data is saved in a local memory; the local memory is preferably a flash memory, that is, the wireless communication motion capture device also has a local memory connected to its first control module.

[0130] When the wireless communication motion capture device stops sending data, it enters a retransmission mode, responds to the missing frame retransmission request queried by the signal receiving end, and retransmits the frame number corresponding to the missing frame retransmission request.

[0131] For details, please refer to Figure 7 , the motion capture system performs the following steps when performing data synchronization:

[0132] Step S700: The wireless communication motion capture device starts with an integer number of seconds of delay according to the set acquisition frame rate and sends data at fixed intervals. The delayed start is to synchronize the acquisition based on the aligned time to ensure that the data is collected and calculated at the same time. The fixed time interval is calculated using a synchronized timestamp to ensure the uniformity of subsequent acquisition times.

[0133] Step S800: The wireless communication motion capture device sends data while keeping the data in the local memory. Wireless real-time communication generally adopts a communication method without a retransmission mechanism, and data loss is inevitable; while sending data in real time, the data is saved to the Flash for the purpose of supplementing the lost data at a later time.

[0134] Step S900: The wireless communication motion capture device stops sending data and enters the retransmission mode, retransmitting data according to the missing frames queried by the signal receiving end (e.g., the host computer). The retransmission query is based on the frame number data of the data. The cache and retransmission mechanism ensures that the data is fully transmitted without data omission.

[0135] Flash cache provides a temporary storage space for data. When an exception occurs during data transmission, the cached data can be reissued in time to ensure data integrity. At the same time, this mechanism also fully takes into account the needs of real-time application scenarios. In some application scenarios with high real-time requirements, data integrity and timeliness are both crucial. This mechanism of this embodiment can ensure that data can be processed and applied in a timely manner while ensuring data integrity, meeting the needs of real-time application scenarios.

[0136] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A wireless communication motion capture device, characterized in that: include: Basic module, synchronization contacts, charging contacts, first control module; The first control module is respectively connected to the basic module, the synchronization contact and the charging contact, drives the basic module to complete the main function, sends a confirmation signal in response to the synchronization command signal received by the charging contact, receives the synchronization signal through the synchronization contact, and then performs the timestamp alignment operation.

2. The wireless communication motion capture device according to claim 1, characterized in that: It comprises a docking position, on which the synchronization contact and the charging contact are arranged.

3. The wireless communication motion capture device according to claim 2, characterized in that: The docking position is a planar structure or an eccentric structure.

4. The wireless communication motion capture device according to claim 2, characterized in that: The docking position includes a magnetic attraction component.

5. The wireless communication motion capture device according to claim 1, characterized in that: The basic module includes a motion capture unit, a first wireless communication module, and an energy storage module; The motion capture unit and the first wireless communication module are connected to the first control module respectively; the energy storage module is connected to the charging contact.

6. The wireless communication motion capture device according to claim 1, characterized in that: The synchronization contact includes one or more small contacts.

7. A charging stand, characterized in that: include: Power module, synchronization ejector pin, charging ejector pin, second control module; The power module is connected to the charging pin; The second control module is connected to the synchronization pin and the charging pin respectively, sends a synchronization command signal through the charging pin, and sends a synchronization signal through the synchronization pin in response to a confirmation signal received by the charging pin.

8. The charging stand according to claim 7, characterized in that: The number of the synchronous ejector pins is one or more; the number of the charging ejector pins is one or more; A synchronization pin and a charging pin are associated with each other.

9. The charging stand according to claim 8, characterized in that: including one or more charging stations; Each of the charging positions has a synchronization pin and a charging pin associated with the synchronization pin.

10. The charging stand according to claim 9, characterized in that: The charging position is a planar structure or an eccentric structure.

11. A method for time synchronization of a wireless communication motion capture device, applied to a wireless communication motion capture device, characterized in that: include: In response to a synchronization command signal received by the charging contact, sending a determination signal through the charging contact to enter a synchronization mode; The timestamp alignment is performed in response to a synchronization signal received by the synchronization contact.

12. The method for time synchronization of wireless communication motion capture equipment according to claim 11, characterized in that: The synchronization signal is a synchronization square wave of a predetermined period; The timestamp alignment specifically includes: Obtaining a time point corresponding to the first rising edge of the received synchronization square wave as a pre-adjustment timestamp; The predetermined time value transmitted by the host computer is obtained by wireless communication, and the preset timestamp is adjusted to the predetermined time value.

13. The method for time synchronization of wireless communication motion capture equipment according to claim 11, characterized in that: When the wireless communication motion capture device charging operation is completed, the timestamp is maintained through the built-in timer and / or the time calibration signal of the host computer.

14. A method for time synchronization of wireless communication motion capture equipment, applied to a charging station, characterized in that: include: In response to the charging contact connection operation of the wireless communication motion capture device, a synchronization command signal is sent through the charging ejector pin at a fixed time; In response to the determination signal received through the charging pin, a synchronization signal is sent through the synchronization pin.

15. The method for time synchronization of wireless communication motion capture equipment according to claim 14, characterized in that: There are one or more synchronization pins; there are one or more charging pins; one synchronization pin is associated with one charging pin; The synchronization method comprises: When a charging contact performs a charging access operation, a synchronous command signal is sent through the charging pin corresponding to the charging contact at a fixed time; In response to a determination signal received through the charging pin corresponding to the charging contact, a synchronization signal is sent through a synchronization pin associated with the charging pin.

16. The method for time synchronization of wireless communication motion capture equipment according to claim 15, characterized in that: When a plurality of the wireless communication motion capture devices are charged in the same time period, the method includes the following steps: Sending synchronization commands to all the wireless communication motion capture devices simultaneously and regularly; After receiving the confirmation signals fed back by all the wireless communication motion capture devices, the synchronization signal is triggered for all the wireless communication motion capture devices simultaneously or in a predetermined order.

17. A wireless communication motion capture device time synchronization system, characterized in that: It comprises the charging stand described in any one of claims 7-10, and the wireless communication motion capture device described in any one of claims 1-6.

18. A motion capture system, characterized in that: include: One or more wireless communication motion capture devices as described in any one of claims 1 to 6; The signal receiving end includes a second wireless communication module, and exchanges data with one or more of the wireless communication motion capture devices through the second wireless communication module.

19. The motion capture system according to claim 18, characterized in that: The wireless communication motion capture device starts with an integer second delay and sends data at fixed intervals according to the set frame rate; at the same time, the data is saved to the local storage; When the wireless communication motion capture device stops sending data, it enters a retransmission mode, responds to the missing frame retransmission request queried by the signal receiving end, and retransmits the frame number corresponding to the missing frame retransmission request.

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