Sensor data acquisition method

Abstract

The invention discloses a sensor data acquisition method, and relates to the field of humanoid robots. Aiming at the problems of difficult wiring, vulnerable wiring harnesses, poor data synchronism, transmission packet loss and the like in the existing multi-sensor wired connection, a wireless architecture of a main node and sub-nodes is adopted: the main node generates and issues a synchronizing signal to calibrate a sub-node clock, the sub-nodes collect sensor data and generate a double-serial-number identifier, and the double-serial-number identifier is wirelessly reported after being packaged; and the main node triggers retransmission through double serial number verification, and calls a corresponding protocol to analyze data according to the sensor type. The core algorithm ensures time synchronization and data reliability, and the modular design adapts to multiple types of sensors. The method thoroughly solves the wiring problem, improves the stability and adaptation flexibility of data acquisition, is easy to implement and maintain, and is suitable for a robot multi-sensor collaborative acquisition scene.

Description

Technical Field

[0001] This invention relates to the field of humanoid robots, and more specifically to a sensor data acquisition method. Background Technology

[0002] With the rapid development of humanoid robot technology, robots need to be equipped with various sensors, such as six-dimensional force sensors, vision sensors, and inertial sensors, to meet complex functional requirements. In existing technologies, data transmission between sensors and robot control boards generally uses wired connections, leading to the following problems: Wiring is difficult: There are many sensors distributed in various parts of the robot (such as the wrist and joints of the robotic arm), and the number of wires is huge. Some sensors (such as the six-dimensional force sensor in the wrist of the robotic arm) cannot be wired inside the robot due to limited installation space and can only be exposed on the outside. Exposed wiring harnesses are easily damaged by external friction and collisions, which can directly lead to interruption of data communication and may cause unpredictable consequences such as loss of robot control. Existing wireless sensing solutions only achieve simple wireless data transmission, without solving the problem of time synchronization of data from multiple sensors, and are subject to data loss and mismatch risks, thus failing to meet the needs of time-sensitive scenarios such as dynamic force control and precision operation of robots.

[0003] Therefore, there is an urgent need for a data acquisition method that can solve wiring problems, improve data synchronization accuracy and reliability, and be compatible with multiple types of sensors. Summary of the Invention

[0004] The purpose of this invention is to provide a sensor data acquisition method to solve the problems of difficult wiring, exposed and easily damaged wire harnesses, and low data communication reliability caused by the wired connection of multiple sensors in existing robots.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A sensor data acquisition method for collaborative data acquisition of multiple sensors in a robot includes the following steps: Step 1): The master node generates and sends out a synchronization signal, which is used to calibrate the acquisition clock of each sub-node; Step 2): After receiving the synchronization signal, each sub-node collects the target data of the corresponding sensor and generates a dual sequence number identifier, which includes a message sequence number and a pulse sequence number. Step 3): The sub-nodes package the target data and the dual sequence number identifier into a data frame and report it to the master node via short-range wireless communication. Step 4): After receiving the data frame, the master node performs an integrity check on the data frame based on the dual sequence number identifier. If the check passes, the target data is parsed; if the check fails, a retransmission mechanism is triggered. Step 5): The master node adapts to the corresponding parsing protocol according to the sensor type to complete the parsing and output of the target data; The core algorithms involved include: Time synchronization calibration algorithm: ,in: : Data acquisition timestamps after node calibration (unit: seconds); : The reference timestamp of the master node synchronization signal (unit: seconds); The transmission delay (in seconds) of the synchronization signal from the master node to the slave node is obtained by measuring the round-trip communication delay. Initial deviation between the local clock of the sub-node and the clock of the master node (unit: s), calibrated once when the system starts up; Double sequence number check retransmission algorithm: Let the sequence number of the currently received message be... Pulse sequence number is The sequence number of the last received valid message was Pulse sequence number is ,but: Sequence continuity judgment: , ; Validation logic: When and When, the data frame is determined to be complete and valid; when or When data packet loss or out-of-order delivery is detected, a retransmission command is triggered. Retransmission command triggering conditions: ( This indicates that a retransmission has been triggered. (Indicates not to trigger), where .

[0006] Further, the synchronization signal mentioned in step 1) is a high-precision hardware synchronization pulse. The master node generates the synchronization pulse through a signal synchronization processing unit, and the frequency of the synchronization pulse can be dynamically adjusted according to the sensor type; the frequency f of the synchronization pulse satisfies Frontier Time Through formula Adaptive adjustment, where k is the adaptation coefficient ( ), This corresponds to the inherent sampling frequency of the sensor.

[0007] Further, the message sequence number mentioned in step 2) is an n-bit binary number ( The pulse sequence number increments by natural numbers starting from the start of data acquisition; each pulse sequence number corresponds one-to-one with the synchronization pulse sent by the master node, and the pulse sequence number increments by 1 for each synchronization pulse sent, and the pulse sequence number corresponds to the reference timestamp of the synchronization pulse. satisfy ,in f is the system startup time, and f is the synchronization pulse frequency.

[0008] Furthermore, the integrity verification in step 4) also includes data frame checksum verification, and the algorithm for calculating the checksum C is as follows: ,in This represents the XOR operation. The checksum is the data in the i-th byte of the data frame, and m is the total number of bytes involved in the checksum verification. The master node recalculates the checksum after receiving the data frame. ,when If the data frame is found to have no transmission errors, it is determined that there are no transmission errors; otherwise, a retransmission is triggered.

[0009] Furthermore, the multimodal adaptation described in step 5) is achieved through a modular interface. The sub-nodes are compatible with force sensors, vision sensors, and inertial sensors by changing the interface adaptation unit. The main node pre-stores the parsing protocols of various sensors and calls the corresponding protocol through the sensor type identifier Type, where Type is a 2-bit binary number, and different values ​​correspond to different sensor types. When Type is an undefined combination (binary 00, 11), the master node triggers a dual-mode processing mechanism: if the data frame conforms to the general sensor raw data format (8-bit byte stream without structured identifier), the general parsing protocol is called to extract the raw byte data and mark it as "unfitted type"; if the data frame format is abnormal, an "invalid sensor type identifier" alarm is immediately reported to the robot control system, and the data reception of the sub-node is suspended, while an exception log is recorded (including sub-node ID, Type value, and exception occurrence timestamp).

[0010] Furthermore, the short-range wireless communication method mentioned in step 3) is one or more combinations of UWB, Bluetooth, or WiFi. The sub-node adopts an integrated packaging structure of "data acquisition board + hardware synchronization module + micro wireless module", which does not require external wiring harnesses.

[0011] The present invention has the following beneficial effects: This invention completely avoids the wiring problems caused by traditional wired connections and eliminates the reliability risks caused by exposed wire harnesses through the wireless architecture design of the master node and the sub-node and the integrated packaging structure of the sub-node. By leveraging hardware-level time synchronization mechanisms and calibration algorithms, time consistency calibration of multi-sensor data is achieved, meeting the usage requirements of robots in time-sensitive scenarios. By employing a dual-sequence number verification and retransmission mechanism and data checksum verification, packet loss, out-of-order transmission, and transmission errors are effectively avoided during data transmission, ensuring the integrity and accuracy of data acquisition. Relying on modular interface design and pre-stored parsing protocols, flexible adaptation to multiple types of sensors is achieved, reducing the operational complexity of sensor expansion and replacement. It adopts mature short-range wireless communication technology and integration process, simplifies system assembly and maintenance process, and has strong practicality and potential for large-scale application. Attached Figure Description

[0012] Figure 1 The diagram illustrates the specific steps of the method of this invention. Figure 2 This is a schematic diagram of the system architecture of the present invention; Figure 3 This is a block diagram of the internal structure of the main node of the present invention.

[0013] Among them: 100 highest-level components, 110 secondary components, and 111 low-level parts. Detailed Implementation

[0014] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0015] See Figures 1 to 3 As shown, a sensor data acquisition method for collaborative data acquisition of multiple sensors in a robot includes the following steps: Step 1: The master node generates and sends out a synchronization signal, which is used to calibrate the acquisition clock of each sub-node; Step 2: After receiving the synchronization signal, each sub-node collects the target data of the corresponding sensor and generates a dual sequence number identifier, which includes a message sequence number and a pulse sequence number. Step 3: The sub-nodes package the target data and the dual sequence number identifier into a data frame and report it to the master node via short-range wireless communication. Step 4: After receiving the data frame, the master node performs integrity verification on the data frame based on the dual sequence number identifier. If the verification passes, the target data is parsed; if the verification fails, the retransmission mechanism is triggered. Step 5: The master node adapts to the corresponding parsing protocol according to the sensor type to complete the parsing and output of the target data.

[0016] Step 1: Generation and distribution of master node synchronization signals Master node hardware selection: The master node is integrated into the robot control board (the highest level component of level 100). The signal synchronization processing unit (SPU) is a high-precision clock module (model: OCXO-1000) based on GPS synchronization technology, which outputs 1PPS synchronization pulses with a time accuracy of ≤1μs. The wireless gateway module is a UWB communication chip (model: DW1000) which is responsible for transmitting synchronization signals and receiving data.

[0017] Synchronization signal parameter refinement: The synchronization signal is a hardware synchronization pulse with a leading-edge time ≤ 15ns and a pulse width of 100ms; the synchronization pulse frequency is determined by the formula... Adaptive adjustment, where the adaptation coefficient k is dynamically set according to the sensor type: Example 1: Six-dimensional force sensor (inherent sampling frequency) ),Pick Then the synchronization pulse frequency Suitable for precision force control scenarios; Example 2: Visual sensor (inherent sampling frequency) ),Pick Then the synchronization pulse frequency To balance sampling accuracy and power consumption.

[0018] Distribution logic: After the system starts, the main control module (ARM Cortex-M7 core) of the master node controls the SPU initialization, generates a synchronization pulse of a set frequency, and broadcasts it to all sub-nodes through the low-latency channel (transmission delay ≤10ms) of the UWB wireless gateway module to ensure that each sub-node receives the synchronization signal at the same time.

[0019] Step 2: Node Data Acquisition and Dual Sequence Number Generation Sub-node hardware selection: The sub-node (110-level secondary components) adopts an integrated packaging structure of "data acquisition board + hardware synchronization module + micro wireless module". The micro wireless module is a miniaturized UWB module (model: DW1000-Mini, size ≤10mm×10mm×3mm), which is integrated with the sensor housing by injection molding and does not require external wiring harness; the hardware synchronization module adopts a high-speed comparator (model: AD8561) with a response time ≤5ns.

[0020] Data acquisition process: After receiving the synchronization pulse, the hardware synchronization module of each node immediately triggers the sensor to acquire target data (such as a six-dimensional force sensor acquiring X / Y / Z axis force and torque data with a sampling accuracy of 16 bits); simultaneously, the data acquisition board generates a dual-serial identifier: Message sequence number: Uses an 8-bit binary number, incrementing by natural numbers from the start of data collection (00000001→00000002→...→11111111, looping after overflow); Pulse sequence number: Corresponds one-to-one with the master node synchronization pulse. The sequence number increments by 1 for each synchronization pulse sent, and is determined by the formula... Calculation and verification: Assuming system startup time The reference timestamp of a certain synchronization pulse Synchronization frequency ,but It is consistent with the synchronization pulse sequence number.

[0021] Step 3: Data Frame Packaging and Wireless Reporting Data frame structure: Each node packages the target data (e.g., 6 sets of 16-bit data from a six-dimensional force sensor, totaling 12 bytes), dual sequence number identifiers (1 byte for message sequence number + 1 byte for pulse sequence number), and sensor type identifier into a data frame. The total number of bytes in the data frame is... Bytes (including checksum bytes).

[0022] Wireless communication method: UWB short-range wireless communication is adopted, with a communication distance of 0-10m, which meets the communication needs of sensors in various parts of the robot and the main node; the micro wireless module adopts a low-power design with a standby current of ≤8μA, and is powered by a built-in battery with a battery life of ≥1000h.

[0023] Step 4: Master Node Integrity Verification and Retransmission Dual sequence number verification process: After the master node receives the data frame, the data verification module (a module under the core unit of the level 100 master node) extracts the message sequence number. and pulse sequence number Compared with the previous valid serial number , contrast: Normal scenario: ; The data is deemed valid. Packet loss scenarios: Trigger retransmission ( ).

[0024] Checksum verification: by algorithm Calculate the first 14 bytes of data in the example data frame. , ,but The master node recalculates after receiving the data. The result matches the checksum in the data frame, indicating no transmission error.

[0025] Retransmission mechanism: The master node sends a retransmission command to the corresponding sub-node through the wireless gateway module. After receiving the command, the sub-node re-reports the data frame within 1ms to ensure data integrity.

[0026] Step 5: Data Parsing and Output Multimodal adaptation implementation: The master node pre-stores the parsing protocols for various sensors, and calls the corresponding protocol through the sensor type identifier (Type) in the data frame. (Binary): Six-dimensional force sensor, parsing protocol is "converting 16-bit digital data into force / torque physical quantities (unit: N / N)". m), range ±500N / ±50N m”; (Binary): Visual sensor, the parsing protocol is "extracting parameters such as image pixel coordinates and grayscale values".

[0027] Data output: The main control module converts the parsed target data into control parameters that the robot can recognize, and transmits them to the robot execution unit via the bus to achieve real-time control (such as using six-dimensional force data for force control adjustment of the robotic arm).

[0028] Part classification application Top-level component 100: Master node core unit (main control module, SPU); Secondary component 110: Sub-node packaging unit, wireless gateway module; Low-level component 111: Interface adapter unit (connection interface between sub-node and sensor), miniature antenna, for easy individual replacement and maintenance.

[0029] Formula and Terminology Clarification Time synchronization calibration algorithm:

[0030] Clarification of Terminology Definitions: The system time recorded when the master node sends out a synchronization pulse is provided by the master node's high-precision clock module, with an accuracy of up to 1 ns. Synchronization signal transmission delay is calculated by the round-trip time delay of "master node sends synchronization pulse → slave node receives and immediately replies with acknowledgment signal → master node receives acknowledgment signal", and the formula is as follows: ,in The time the master node sends the message. The time it takes for the master node to receive the acknowledgment signal; The initial deviation between the local clock of the sub-node and the clock of the master node is calibrated once when the system starts up. The calibration command is sent by the master node, and the sub-nodes compare their local clocks with the master node time in the calibration command to obtain the deviation.

[0031] Example calculation: Assumption Round trip delay ,but The system was calibrated at startup. ,but This refers to the data acquisition timestamp after node calibration, ensuring that the time synchronization accuracy of each node is ≤1μs.

[0032] Double sequence number check retransmission algorithm Clarification of term definitions: The sequence number of the currently received data frame is used to identify the collection batch and ensure that the data is transmitted in the order of collection. The pulse sequence number of the currently received data frame is used to associate the synchronization signal and ensure that the data corresponds one-to-one with the synchronization time. R: Retransmission trigger flag, triggered only when sequence numbers are not consecutive, to avoid invalid retransmissions.

[0033] By using a dual constraint of "message sequence number (collection batch) + pulse sequence number (synchronization time)," the problems of "data packet loss" and "time mismatch" are solved simultaneously: if only the message sequence number is checked, there may be a situation where "collection batches are continuous but synchronization time is misaligned"; if only the pulse sequence number is checked, there may be a situation where "synchronization time is continuous but collected data is missing". Dual verification ensures data integrity and time consistency.

[0034] Checksum algorithm:

[0035] Clarification of Terminology Definitions: The XOR operation follows the logic rule of "0 for the same, 1 for different". It is simple to operate and has strong anti-interference capabilities, making it suitable for error detection in data frame transmission. The data in the i-th byte of the data frame includes the target data, the double sequence number identifier, and the sensor type identifier, but does not include the checksum itself; m: The total number of bytes involved in the checksum in the data frame, i.e., the total number of bytes excluding the checksum byte.

[0036] Example calculation: Assume the number of bytes in the data frame used for verification is... , but The master node recalculates after receiving the data. The data frame was determined to have no transmission errors.

[0037] Synchronization frequency adjustment formula:

[0038] Clarification of Terminology Definitions: k: Fit coefficient, range of values The value is dynamically set by the master node according to the sensor's functional requirements. A larger value is used when the function priority is high (such as force control), and a smaller value is used when the function priority is low (such as environmental monitoring). The inherent sampling frequency of a sensor is determined by its hardware parameters and is the maximum frequency at which the sensor can stably output data.

[0039] "The synchronization frequency should not exceed the inherent sampling frequency of the sensor" to avoid the sensor from being unable to respond due to an excessively high synchronization frequency. At the same time, the "data update speed" and "system power consumption" are balanced by the adaptation coefficient. For example, since the inherent sampling frequency of the vision sensor is low, taking a smaller k can reduce the power consumption of the sub-nodes and extend the battery life.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sensor data acquisition method for collaborative data acquisition of multiple sensors in a robot, characterized in that, Includes the following steps: Step 1: The master node generates and sends out a synchronization signal, which is used to calibrate the acquisition clock of each sub-node; Step 2: After receiving the synchronization signal, each sub-node collects the target data of the corresponding sensor and generates a dual sequence number identifier, which includes a message sequence number and a pulse sequence number. Step 3: The sub-nodes package the target data and the dual sequence number identifier into a data frame and report it to the master node via short-range wireless communication. Step 4: After receiving the data frame, the master node performs an integrity check on the data frame based on the dual sequence number identifier. If the check passes, the target data is parsed; if the check fails, a retransmission mechanism is triggered. Step 5: The master node adapts to the corresponding parsing protocol based on the sensor type to complete the parsing and output of the target data; the core algorithm includes: a) Time synchronization calibration algorithm: , This is the data acquisition timestamp after node calibration. The reference timestamp for the master node synchronization signal. To delay the transmission of synchronization signals, This represents the initial clock offset between the branch node and the master node; b) Double sequence number check retransmission algorithm: , ,or , Retransmission is triggered at that time.

2. The sensor data acquisition method according to claim 1, characterized in that, The synchronization signal mentioned in step one is a high-precision hardware synchronization pulse, which is generated by the master node through the signal synchronization processing unit.

3. The sensor data acquisition method according to claim 1 or 2, characterized in that, The frequency of the synchronization pulse in step one is obtained through the formula... Adaptive adjustment, where k is the adaptation coefficient. This corresponds to the inherent sampling frequency of the sensor.

4. The sensor data acquisition method according to claim 1, characterized in that, The message sequence number mentioned in step two is an n-bit binary number ( The numbers are incremented sequentially according to the acquisition order; each pulse number corresponds one-to-one with a synchronization pulse, and the number increments by 1 each time a synchronization pulse is sent.

5. The sensor data acquisition method according to claim 1, characterized in that, Step four of the integrity verification also includes checksum verification, checksum... , For XOR operation, Let m be the data of the i-th byte in the data frame, and m be the total number of bytes participating in the verification.

6. The sensor data acquisition method according to claim 1, characterized in that, The short-range wireless communication method mentioned in step three is one or a combination of UWB, Bluetooth, or WiFi.

7. The sensor data acquisition method according to claim 1, characterized in that, In step five, the sensor type is distinguished by a 2-bit binary identifier Type. The master node pre-stores the parsing protocols for various types of sensors and calls the corresponding protocol based on Type.

8. The sensor data acquisition method according to claim 1, characterized in that, The sub-node adopts an integrated packaging structure of "data acquisition board + hardware synchronization module + micro wireless module", which does not require external wiring harness.

9. The sensor data acquisition method according to claim 1, characterized in that, The initial deviation A one-time calibration is completed when the system starts up, via calibration instructions issued by the master node.

10. The sensor data acquisition method according to claim 1, characterized in that, After the retransmission command is issued in step four, the sub-nodes need to complete the data retransmission within a preset time. If no response is received within the time limit, the master node will trigger the retransmission again.

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