EtherCAT wired-to-wireless robotic arm control system

Abstract

This invention discloses an EtherCAT wired-to-wireless robotic arm control system, comprising a management center PLC, a robotic arm wireless communication management center, multiple robotic arm wireless communication terminals, and multiple communication terminal lower-level PLCs. The management center PLC is connected to the robotic arm wireless communication management center via an EtherCAT bus. The robotic arm wireless communication management center is connected to the multiple robotic arm wireless communication terminals via frequency hopping wireless communication technology (FHSS). Data transmission between the robotic arm wireless communication terminals and the robotic arm wireless communication management center is performed using an encryption algorithm. Each of the multiple robotic arm wireless communication terminals is connected to one of the multiple communication terminal lower-level PLCs via an EtherCAT bus. This invention employs FHSS frequency hopping technology, effectively avoiding the influence of operating conditions and electromagnetic interference signals, thus effectively ensuring work efficiency.

Description

Technical Field

[0001] This invention relates to the field of robotics, and in particular to an EtherCAT wired-to-wireless robotic arm control system. Background Technology

[0002] A robotic arm is a complex system characterized by high precision, multiple inputs and multiple outputs, high nonlinearity, and strong coupling. Due to its unique operational flexibility, it has been widely used in numerous fields such as industrial assembly, safety, and explosion protection.

[0003] Currently, most existing robotic arm systems use the EtherCAT bus to enable data communication between management nodes and various terminal nodes, transmitting production parameters, operating status information, and control commands in real time, quickly, and accurately. However, in actual production processes, robotic arms need to perform various operations and corresponding movements for extended periods, such as moving back and forth, flipping up and down, and rotating left and right. Over time, the wired EtherCAT data cable at the end of the robotic arm is prone to tangling, detachment, or breakage, leading to equipment misalignment or even shutdown. This can range from minor production disruptions, delays, and reduced efficiency to serious accidents or even major incidents, causing irreparable losses to the production unit. Therefore, production units urgently need a highly efficient and stable robotic arm system that can convert wired EtherCAT communication to wireless communication to overcome the current drawbacks and address the aforementioned problems.

[0004] Currently, there are various wireless communication methods, such as 4G, 5G, Bluetooth, WiFi, ZigBee, and infrared. Since 4G and 5G require SIM cards, data communication incurs costs, resulting in high costs. Bluetooth, WiFi, and ZigBee, on the other hand, occupy the ISM band and do not incur communication costs. However, due to the complex working conditions in production workshops, such as strong interference signals like electromagnetic signals, Bluetooth, WiFi, and ZigBee cannot resist interference signals, leading to data packet loss and making it impossible to ensure stable and reliable data communication. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this invention is to provide an EtherCAT wired-to-wireless robotic arm control system. This invention employs FHSS frequency hopping technology, which effectively avoids the influence caused by operating conditions and electromagnetic interference signals, thus effectively ensuring work efficiency.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: an EtherCAT wired-to-wireless robotic arm control system, comprising a management center upper computer PLC, a robotic arm wireless communication management center, multiple robotic arm wireless communication terminals, and multiple communication terminal lower computer PLCs; the management center upper computer PLC is communicatively connected to the robotic arm wireless communication management center via an EtherCAT bus, the robotic arm wireless communication management center is communicatively connected to the multiple robotic arm wireless communication terminals via frequency hopping wireless communication technology (FHSS), and the robotic arm wireless communication terminals and the robotic arm wireless communication management center transmit data through an encryption algorithm; the multiple robotic arm wireless communication terminals are each communicatively connected to the multiple communication terminal lower computer PLCs one by one via an EtherCAT bus.

[0007] As a further improvement of the present invention, the data transmission between the robotic arm wireless communication terminal and the robotic arm wireless communication management center via an encryption algorithm specifically includes the following steps:

[0008] Step 1: First transmission of raw data: The sender adds a frame header flag to the beginning of the raw data, and adds a data end flag, the length information of the raw data, and the error control information to the end of the raw data. Then, it adds a frame tail flag. The receiver receives the data according to the transmission protocol. After the raw data is received, the receiver first verifies whether the received data contains the frame header flag, data end flag, and frame tail flag in sequence. If it does, the receiver counts the length of the received raw data, generates error control information on-site according to the established error control protocol, and then compares the received data length information with the on-site data length information and the received error control information with the on-site generated error control information. If the comparison results of the two types of information are consistent, it means that the received information is complete, and the receiver immediately returns an acknowledgment flag to the sender indicating that the first received data is complete.

[0009] Step 2: Second Transmission of Encrypted Data: After receiving the data acknowledgment flag from the receiver, the sender transmits the data a second time. This second transmission is a new data form after encrypting the original data from the first transmission; the sender adds a frame header flag to the beginning of the encrypted data, a data end flag, and data values ​​for the length and error control information of the encrypted data. Finally, a frame tail flag is added. The receiver receives the encrypted data according to the transmission protocol. After receiving the encrypted data, the receiver first verifies whether the received data contains the frame header, data end, and frame tail flags. If so, the receiver counts the length of the received data, generates error control information on-site according to the established error control protocol, and compares the length of the received encrypted data with the length of the on-site encrypted data. The receiver also compares the received error control information with the on-site generated error control information. If both comparisons are consistent, the received information is complete, and the receiver immediately returns an acknowledgment flag indicating that the second received encrypted data is complete.

[0010] Step 3: Upon receiving the second acknowledgment flag, the receiver indicates that the second data reception was complete. It then decrypts the received encrypted data according to the encryption protocol, obtaining a set of decrypted data. The decrypted data is then compared and analyzed with the original data to verify if the two received data are identical. If they are identical, the data is stored in a designated memory location, and a data integrity flag is sent back to the sender. If they are different, the data is invalid and is not stored, and an abnormal data flag is sent back to the sender. If the sender receives a data integrity flag, it executes subsequent program instructions; if it receives an abnormal data flag, it repeats steps 1 and 2.

[0011] As a further improvement of the present invention, if the data received does not contain the three data frame flags—frame header flag, data end flag, and frame tail flag—or is not in the order of frame header flag, data end flag, and frame tail flag, then the data received by the receiver is invalid. Additionally, if the received data length information is inconsistent with the data length information generated on-site, or if the received error control information is inconsistent with the error control information generated on-site, it also indicates that the data received by the receiver is invalid, and the receiver returns a received data invalid flag value to the sender. Upon receiving the data invalid flag value from the receiver, the sender needs to retransmit the original data that was just sent incorrectly until the original data is completely transmitted.

[0012] As a further improvement of the present invention, the encryption of the original data specifically includes:

[0013] Based on the original data transmitted in the first transmission, encryption is performed according to a certain mathematical method to generate a new set of data related to the original data transmitted in the first transmission, namely encrypted data. The mathematical method is to take the original data transmitted in the first transmission as the parameter of a certain fixed mathematical expression or function, and then the result generated after the mathematical expression or function is operated is used as the encrypted new data.

[0014] As a further improvement of the present invention, in step 2, the encryption of the original data specifically includes: if the received data does not contain the three data frame flag values—frame header flag, data end flag, and frame tail flag—or is not in the order of frame header flag, data end flag, and frame tail flag, then the data received by the receiver is invalid; in addition, if the received data length information is inconsistent with the data length information generated on-site, or if the received error control information is inconsistent with the error control information generated on-site, it also indicates that the data received by the receiver is invalid, and the receiver returns a received data invalid flag value to the sender; when the sender receives the data invalid flag value sent by the receiver, it needs to resend the encrypted data that was just sent with an error until the encrypted data is sent completely.

[0015] As a further improvement of the present invention, each of the robotic arm wireless communication terminals includes a high-performance processor and an FHSS wireless module, an EtherCAT bus interface, a production parameter acquisition module, a data display module, and an early warning information module connected to the high-performance processor.

[0016] As a further improvement of the present invention, the robotic arm wireless communication management center includes a high-performance microprocessor and an FHSS wireless module, an EtherCAT bus interface, and a production parameter / early warning information display module connected to the high-performance microprocessor. The production parameter / early warning information display module is communicatively connected to multiple robotic arm wireless communication terminals.

[0017] The beneficial effects of this invention are:

[0018] 1. In this invention, wireless communication between the robotic arm terminal and the wireless management center effectively avoids malfunctions such as data cable tangling, breakage, or detachment, thereby effectively preventing equipment misalignment and downtime losses caused by data cable tangling, breakage, or detachment. This significantly improves production efficiency.

[0019] 2. This invention uses FHSS frequency hopping technology, which effectively avoids the influence caused by operating conditions and electromagnetic interference signals, and effectively ensures work efficiency.

[0020] 3. This invention reduces maintenance caused by data cable tangling, breakage, or detachment, lowers production costs, and effectively promotes production efficiency.

[0021] 4. In this invention, the robotic arm's wireless communication terminal needs to exchange data between the EtherCAT bus and the FHSS wireless communication method. This involves a significant amount of data processing, fusion, encryption, and corresponding algorithms. If the EtherCAT bus is converted to the FHSS wireless communication method, the EtherCAT bus data must be extracted before data exchange. After extraction, wireless transmission must be performed according to the FHSS data format. Conversely, if the FHSS wireless communication method is converted to the EtherCAT bus, the FHSS data must be extracted before interaction. After extraction, transmission must be performed according to the EtherCAT bus data format.

[0022] 5. This invention utilizes frequency hopping spread spectrum (FHSS) wireless communication technology, which has strong anti-interference capabilities, and employs a highly efficient data encryption algorithm to effectively avoid data packet loss, thereby ensuring efficient data communication. Attached Figure Description

[0023] Figure 1 This is a block diagram of the system design for the wireless communication function of the robotic arm based on EtherCAT in an embodiment of the present invention;

[0024] Figure 2 This is a block diagram illustrating the functional design of the robotic arm wireless communication terminal in an embodiment of the present invention.

[0025] Figure 3 This is a block diagram illustrating the functional design of the robotic arm wireless communication management center in an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of a complete original data frame in an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of a complete encrypted data frame in an embodiment of the present invention. Detailed Implementation

[0028] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] Example

[0030] An EtherCAT wired-to-wireless robotic arm control system is disclosed. This system is a many-to-one system, consisting of multiple robotic arm wireless communication terminals, multiple lower-level PLCs for these terminals, a robotic arm wireless communication management center, and a higher-level PLC for the management center. Figure 1 As shown, the robotic arm wireless communication terminal is a node of the robotic arm working on-site. Its main function is to collect production data related to on-site production, then classify, screen, and analyze it to effectively grasp the current working status and condition of the robotic arm. If any abnormality is detected, it can automatically issue an early warning and stop the machine. Next, the data is aggregated and packaged, and transmitted accurately to the lower-level PLC according to the EtherCAT bus data format. Simultaneously, it is transmitted to the robotic arm wireless communication management center according to the wireless communication data format. Due to the complex working conditions in the workshop, such as the presence of extremely strong interference signals and electromagnetic signals, to ensure the reliability and data stability of wireless communication—preventing data loss—a strong anti-interference frequency hopping wireless communication technology (FHSS, Frequency Hopping Spread Spectrum) is used, effectively avoiding data loss. Of course, the robotic arm wireless communication terminal can also accurately receive control commands from the lower-level PLC according to the EtherCAT bus data format and execute corresponding actions or operations. Simultaneously, the robotic arm wireless communication terminal can accurately receive relevant control commands from the robotic arm wireless communication management center according to the data format of the FHSS wireless communication method, and execute corresponding actions or operations. Therefore, the robotic arm wireless communication terminal involves data exchange between the EtherCAT bus and the FHSS wireless communication method. If the EtherCAT bus is converted to the FHSS wireless communication method, EtherCAT bus data extraction must be completed before the interaction. After extraction, wireless transmission must be achieved according to the FHSS wireless communication format. Similarly, if the FHSS wireless communication method is converted to the EtherCAT bus, FHSS wireless communication data extraction must be completed before the interaction. After extraction, transmission must be achieved according to the EtherCAT bus format. Therefore, the robotic arm wireless communication terminal consists of multiple modules, such as FHSS wireless, a high-performance microprocessor, an EtherCAT bus interface, production parameter acquisition, data display, and early warning information. Figure 2 As shown. Furthermore, the individual robotic arm wireless communication terminals cannot exchange data with each other. The positions of the robotic arm wireless communication terminals can be either dynamic or fixed.

[0031] The robotic arm wireless communication management center receives production data from various robotic arm wireless communication terminals, then performs classification, screening, analysis, early warning, and summarization to promptly grasp the working status and operation of each terminal. The center can not only proactively query the production data of a specific terminal but also send relevant commands to actively control one, several, or all terminals. The location of the robotic arm wireless communication management center is fixed. It consists of multiple modules, including FHSS wireless communication, a high-performance microprocessor, an EtherCAT bus interface, and displays of production parameters and early warning information for each terminal. Figure 3 As shown.

[0032] The robotic arm's wireless communication terminal transmits data with the robotic arm's wireless communication management center using an encryption algorithm. The encryption algorithm is as follows:

[0033] 1. The first transmission is of raw data. Before transmission, the sender adds a frame header flag "#$%!" to the beginning of the raw data and a data end flag "#$&*" to the end. Next, it adds the length information of the raw data (i.e., the total number of bytes, stored in 2 bytes), error control information (generated according to a pre-defined error control protocol standard), and other data values. Finally, it adds a frame trailer flag "#$@+". This forms a complete raw data frame, such as... Figure 4As shown. Then data transmission proceeds. After all data transmission is complete, the receiver receives data according to the method specified in the transmission protocol. Once the data is received, the receiver first verifies whether the received data contains the flag values ​​of the three data frames "#$%!", "#$&*", and "#$@+" in sequence. If it does, the receiver immediately calculates the length of the received field data; and generates error control information on-site according to the established error control protocol. Then, the receiver compares the received data length information with the field data length information, and compares the received error control information with the on-site generated error control information. If the comparison results of the two types of information are consistent, it means that the received information is complete, and the receiver immediately returns an acknowledgment flag value "#$OK" to the sender indicating that the first received data is complete, signifying that the receiver has completely received the data just transmitted by the sender. If the received data does not contain the three data frame flag values ​​"#$%!", "#$&*", and "#$@+", or is not in the order of "#$%!", "#$&*", and "#$@+", it means that the data received by the receiver is invalid. Additionally, if the received data length information is inconsistent with the data length information generated on-site, or if the received error control information is inconsistent with the error control information generated on-site, it also indicates that the data received by the receiver is invalid. In this case, the receiver returns a received data invalid flag value "#$KR" to the sender. Upon receiving the data invalid flag value "#$KR" from the receiver, the sender needs to retransmit the original data that was just sent incorrectly, that is, retransmit the data according to the aforementioned steps. If the data transmitted this time is also incorrect, the aforementioned steps are continued until the original data is transmitted completely.

[0034] 2. After receiving the data acknowledgment flag "#$OK" from the receiver, the sender knows that the first data transmission has been complete and proceeds with the second data transmission. The second transmitted data is new data—encrypted data—formed by encrypting the first original data. The encryption algorithm works as follows: based on the first transmitted original data, it is encrypted according to a certain mathematical method (the first original data can be used as a parameter of a fixed mathematical expression or function, and the result of the mathematical expression or function is used as the encrypted new data), generating a set of new data related to the first original data—encrypted data. Before transmitting the encrypted data, the sender adds a frame header flag "" / MN" before the encrypted data and a data end flag "" / RT" after the encrypted data. Next, it adds the length information of the encrypted data (i.e., the total number of bytes, stored in 2 bytes), error control information (error control information is generated according to the pre-defined error control protocol standard), and other data values. Finally, it adds a frame tail flag "" / QP". This forms a complete encrypted data frame, such as... Figure 5 As shown. Then data transmission proceeds. After all data transmission is complete, the receiver receives encrypted data according to the transmission protocol. Once the encrypted data is received, the receiver first verifies whether the received encrypted data contains the flag values ​​of the three data frames " / MN", " / RT", and " / QP" in sequence. If it does, the receiver immediately calculates the length of the received data; and generates error control information on-site according to the established error control protocol. Then, the receiver compares the length of the received encrypted data with the length of the on-site encrypted data, and compares the received error control information with the on-site generated error control information. If the comparison results of the two types of information are consistent, it means that the received information is complete, and the receiver immediately returns an acknowledgment value " / YS" indicating that the second received data is complete, signifying that the receiver has completely received the encrypted data just transmitted by the sender. If the received data does not contain the three data frame flag values ​​" / MN", " / RT", and " / QP", or is not in the order of " / MN", " / RT", and " / QP", it means that the data received by the receiver is invalid. Additionally, if the received data length information is inconsistent with the data length information generated on-site, or if the received error control information is inconsistent with the error control information generated on-site, it also indicates that the data received by the receiver is invalid. If the received data is invalid, the receiver returns an invalid data flag value "" / >=" to the sender. Upon receiving the invalid data flag value "" / >=" from the receiver, the sender needs to retransmit the encrypted data that was just sent incorrectly, i.e., retransmit the data following the steps described above. If the data transmitted again fails, the sender continues to follow the steps described above until the encrypted data is transmitted completely.

[0035] 3. Upon receiving " / YS", the receiver indicates that both data receptions are complete. It then decrypts the received encrypted data according to the encryption protocol, obtaining a set of decrypted data. The decrypted data is then compared and analyzed with the first received original data to verify if the two received data are identical. If they are identical, the data is stored in a designated memory location, and a "DATAOK" flag is sent back to the sender. If they are different, the data is invalid and not stored, and an "DATAERROR" flag is sent back to the sender. If the sender receives the "DATAOK" flag, it executes subsequent program instructions. If the sender receives the "DATAERROR" flag, it retransmits the first set of original data following steps 1 and 2.

[0036] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A robotic arm control system for EtherCAT wired-to-wireless communication, characterized in that, The system includes a management center PLC, a robotic arm wireless communication management center, multiple robotic arm wireless communication terminals, and multiple communication terminal lower-level PLCs. The management center PLC communicates with the robotic arm wireless communication management center via an EtherCAT bus. The robotic arm wireless communication management center communicates with the multiple robotic arm wireless communication terminals via frequency hopping wireless communication technology (FHSS). Data transmission between the robotic arm wireless communication terminals and the robotic arm wireless communication management center is performed using an encryption algorithm. Each of the multiple robotic arm wireless communication terminals communicates with each of the multiple communication terminal lower-level PLCs via an EtherCAT bus. The data transmission between the robotic arm wireless communication terminal and the robotic arm wireless communication management center via encryption algorithm specifically includes the following steps: Step 1: First transmission of raw data: The sender adds a frame header flag to the beginning of the raw data, and adds a data end flag, the length information of the raw data, and the error control information to the end of the raw data. Then, it adds a frame tail flag. The receiver receives the data according to the transmission protocol. After the raw data is received, the receiver first verifies whether the received data contains the frame header flag, data end flag, and frame tail flag in sequence. If it does, the receiver counts the length of the received raw data, generates error control information on-site according to the established error control protocol, and then compares the received data length information with the on-site data length information and the received error control information with the on-site generated error control information. If the comparison results of the two types of information are consistent, it means that the received information is complete, and the receiver immediately returns an acknowledgment flag to the sender indicating that the first received data is complete. Step 2: Second Transmission of Encrypted Data: After receiving the data acknowledgment flag from the receiver, the sender transmits the data a second time. This second transmission is a new data form after encrypting the original data from the first transmission; the sender adds a frame header flag to the beginning of the encrypted data, a data end flag, and data values ​​for the length and error control information of the encrypted data. Finally, a frame tail flag is added. The receiver receives the encrypted data according to the transmission protocol. After receiving the encrypted data, the receiver first verifies whether the received data contains the frame header, data end, and frame tail flags. If so, the receiver counts the length of the received data, generates error control information on-site according to the established error control protocol, and compares the length of the received encrypted data with the length of the on-site encrypted data. The receiver also compares the received error control information with the on-site generated error control information. If both comparisons are consistent, the received information is complete, and the receiver immediately returns an acknowledgment flag indicating that the second received encrypted data is complete. Step 3: Upon receiving the second acknowledgment flag, the receiver indicates that the second data reception was complete. It then decrypts the received encrypted data according to the encryption protocol, obtaining a set of decrypted data. This decrypted data is then compared and analyzed with the original data received the first time to verify if the two received data are identical. If they are identical, the data is stored in a designated memory location, and a data integrity flag is sent back to the sender. If they are different, the data is invalid and is not stored, and an abnormal data flag is sent back to the sender. If the sender receives the data integrity flag, it executes subsequent program instructions. If the sender receives the data abnormal flag, it repeats steps 1 and 2. In step 1, if the data received does not contain the three data frame flags—frame header flag, data end flag, and frame trailer flag—or is not in the order of frame header flag, data end flag, and frame trailer flag, then the data received by the receiver is invalid. Additionally, if the received data length information is inconsistent with the data length information generated on-site, or if the received error control information is inconsistent with the error control information generated on-site, it also indicates that the data received by the receiver is invalid, and the receiver returns a received data invalid flag value to the sender. Upon receiving the data invalid flag value from the receiver, the sender must retransmit the original data that was just sent incorrectly until the original data is transmitted completely. In step 2, encrypting the original data specifically includes: Based on the original data transmitted in the first transmission, it is encrypted according to a certain mathematical method to generate a new set of data related to the original data transmitted in the first transmission, namely encrypted data; the mathematical method is to take the original data transmitted in the first transmission as the parameter of a certain fixed mathematical expression or function, and then the result generated after the mathematical expression or function is operated is used as the encrypted new data. In step 2, encrypting the original data specifically includes: if the received data does not contain the three data frame flags—frame header flag, data end flag, and frame tail flag—or is not in the order of frame header flag, data end flag, and frame tail flag, then the data received by the receiver is invalid; in addition, if the received data length information is inconsistent with the data length information generated on-site, or if the received error control information is inconsistent with the error control information generated on-site, it also indicates that the data received by the receiver is invalid, and the receiver returns a received data invalid flag value to the sender; upon receiving the data invalid flag value from the receiver, the sender needs to retransmit the encrypted data that was just sent with an error until the encrypted data is sent completely.

2. The EtherCAT wired-to-wireless robotic arm control system according to claim 1, characterized in that, Each of the robotic arm wireless communication terminals includes a high-performance processor and an FHSS wireless module, an EtherCAT bus interface, a production parameter acquisition module, a data display module, and an early warning information module connected to the high-performance processor.

3. The EtherCAT wired-to-wireless robotic arm control system according to claim 1 or 2, characterized in that, The robotic arm wireless communication management center includes a high-performance microprocessor and an FHSS wireless module, an EtherCAT bus interface, and a production parameter / early warning information display module connected to the high-performance microprocessor. The production parameter / early warning information display module is communicatively connected to multiple robotic arm wireless communication terminals.

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